FN Thomson Reuters Web of Science™ VR 1.0 PT B AU Kroening, SE AF Kroening, SE BE Maxwell, WHC Preul, HC Stout, GE TI Nitrogen and phosphorus in streams in part of the Upper Mississippi River Basin, Minnesota and Wisconsin, 1984-93 SO RIVERTECH '96 - 1ST INTERNATIONAL CONFERENCE ON NEW/EMERGING CONCEPTS FOR RIVERS, PROCEEDINGS, VOLS 1 AND 2: CELEBRATING THE TWENTY-FIFTH ANNIVERSARY OF IWRA LA English DT Proceedings Paper CT 1st International Conference on New/Emerging Concepts for Rivers (RIVERTECH96), Celebrating the 25th Anniversary of IWRA CY SEP 22-26, 1996 CL CHICAGO, IL SP Int Water Resources Assoc, Univ Illinois Urbana Champaign, Univ Illinois Chicago, Univ Cincinnati, Marquette Univ, Metropolitan Reclamat Dist Greater Chicago, Water Dept Chicago, Illinois Dept Nat Resources, US Geol Survey, Harza Engn, Chicago, Ill AB Stream-water nitrogen- and phosphorus-concentration data from part of the Upper Mississippi River Basin were compiled and analyzed as part of a retrospective analysis of existing data for the Upper Mississippi River Basin study unit of the U.S. Geological Survey's National Water-Quality Assessment Program. This data analysis focused on data collected from water years 1984 through 1993 in a study area that encompassed 19,500 square miles in the eastern part of the study unit. The study area included the Mississippi River Basin from Royalton, Minnesota, to the outlet of Lake Pepin; the Minnesota River Basin from Jordan, Minnesota, to the confluence with the Mississippi River; and the entire drainage basins of the St. Croix, Cannon, and Vermillion Rivers. Sources of data were ambient stream-monitoring programs maintained by the Metropolitan Council Environmental Services, Minnesota Pollution Control Agency, US. Geological Survey, and the Wisconsin Department of Natural Resources. Total nitrite plus nitrate nitrogen, total organic plus ammonia nitrogen, total nitrogen, and total phosphorus concentrations were significantly larger in the Minnesota, Straight, and Cannon Rivers, which drain areas with a large percentage of agricultural land, than in the St Croix, Namekagon, and Kettle Rivers, which drain areas with a larger percentage of forested land. In the Mississippi River, nitrogen and phosphorus concentrations varied in the downstream direction Mean concentrations of nitrate and total nitrogen were significantly larger downstream of the confluence with the Minnesota River than upstream. Mean total phosphorus concentrations were significantly larger downstream of wastewater discharges from Newport, Minnesota, to Lock and Dam 3 than mean concentrations upstream of the confluence with the Minnesota River. RP Kroening, SE (reprint author), US GEOL SURVEY,2280 WOODALE DR,MOUNDS VIEW,MN 55112, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU INTERNATIONAL WATER RESOURCES ASSOCIATION PI URBANA PA 205 N MATHEWS AVE, URBANA, IL 61801 PY 1996 BP 37 EP 44 PG 4 WC Water Resources SC Water Resources GA BG72S UT WOS:A1996BG72S00008 ER PT B AU Phillips, JV Hjalmarson, HW AF Phillips, JV Hjalmarson, HW BE Maxwell, WHC Preul, HC Stout, GE TI Implication of translatory-wave phenomena for engineering design SO RIVERTECH '96 - 1ST INTERNATIONAL CONFERENCE ON NEW/EMERGING CONCEPTS FOR RIVERS, PROCEEDINGS, VOLS 1 AND 2: CELEBRATING THE TWENTY-FIFTH ANNIVERSARY OF IWRA LA English DT Proceedings Paper CT 1st International Conference on New/Emerging Concepts for Rivers (RIVERTECH96), Celebrating the 25th Anniversary of IWRA CY SEP 22-26, 1996 CL CHICAGO, IL SP Int Water Resources Assoc, Univ Illinois Urbana Champaign, Univ Illinois Chicago, Univ Cincinnati, Marquette Univ, Metropolitan Reclamat Dist Greater Chicago, Water Dept Chicago, Illinois Dept Nat Resources, US Geol Survey, Harza Engn, Chicago, Ill AB Design-discharge criteria are normally based on the assumption that the discharge associated with a given drainage area in one basin is likely to be experienced in nearby basins that are subjected to similar hydroclimatic conditions. Recent studies suggest several floods that occurred in steep sand channels in the lower Colorado River Basin may not conform to this commonly applied assumption. Results of free-surface instability and wave-celerity computations and several eyewitness accounts indicate that translatory waves may have significantly influenced the peak discharge and peak stage obtained by these floods. Use of conventional hydrologic and hydraulic methodologies for design criteria in channels susceptible to the production of translatory-wave phenomena may result in gross underestimates of peak water-surface elevations. Fully developed translatory waves not only reduce the carrying capacity of a channel, but they also may bring about significant structural damage and even loss of life. Engineers and designers need to consider seriously translatory wave phenomena and the environmental and human hazards associated with them. RP Phillips, JV (reprint author), US GEOL SURVEY,1545 W UNIV DR,TEMPE,AZ 85281, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INTERNATIONAL WATER RESOURCES ASSOCIATION PI URBANA PA 205 N MATHEWS AVE, URBANA, IL 61801 PY 1996 BP 453 EP 460 PG 4 WC Water Resources SC Water Resources GA BG72S UT WOS:A1996BG72S00067 ER PT B AU Morin, R Flamand, R AF Morin, R Flamand, R BE Aubertin, M Hassani, F Mitri, H TI Quantifying lithospheric stress from the shape of oval fractures in a borehole SO ROCK MECHANICS TOOLS AND TECHNIQUES, VOLS 1 AND 2 LA English DT Proceedings Paper CT 2nd North American Rock Mechanics Symposium (NARMS 96) CY JUN 19-21, 1996 CL MONTREAL, CANADA SP Ecole Polytech Montreal, McGill Univ, Canadian Inst Min Met & Petr, Canadian Geotech Soc C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-838-X PY 1996 BP 883 EP 890 PG 8 WC Engineering, Civil; Engineering, Petroleum; Geosciences, Multidisciplinary; Mining & Mineral Processing SC Engineering; Geology; Mining & Mineral Processing GA BF79B UT WOS:A1996BF79B00110 ER PT S AU Fitzgerald, KK Miller, TL Demas, CR Rickert, DA AF Fitzgerald, KK Miller, TL Demas, CR Rickert, DA BE Morgan, JH TI US geological survey protocol for measuring low levels of inorganic constituents, including trace elements, in surface-water samples SO SAMPLING ENVIRONMENTAL MEDIA SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Sampling Environmental Media CY APR 05-07, 1995 CL ALEXANDRIA, VA SP Amer Soc Testing & Mat, Comm D 34 Waste Management DE water quality; water sampling; trace elements C1 US GEOL SURVEY,OFF WATER QUAL,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 SN 1071-5827 BN 0-8031-2043-5 J9 AM SOC TEST MATER PY 1996 VL 1282 BP 329 EP 342 DI 10.1520/STP16582S PG 14 WC Engineering, Environmental SC Engineering GA BG39M UT WOS:A1996BG39M00023 ER PT J AU Slack, JF Passchier, CW Zhang, JS AF Slack, JF Passchier, CW Zhang, JS TI Metasomatic tourmalinite formation along basement-cover decollements, Orobic Alps, Italy SO SCHWEIZERISCHE MINERALOGISCHE UND PETROGRAPHISCHE MITTEILUNGEN LA English DT Article DE tourmalinite; geochemistry; metasomatism; basement-cover decollement; cataclasite; Orobic Alps; Italy ID URANIUM MINERALIZATION; SOUTHERN ALPS; MASS-TRANSFER; VOLUME; ROCKS; METAMORPHISM; DEFORMATION; EVOLUTION; MYLONITES; AUSTRALIA AB Cryptocrystalline tourmalinites that occur discontinuously for similar to 30 km along basement-cover decollements of the Orobic Alps (Italy) formed by the metasomatism of aluminous cataclasites derived from Permian conglomerates and/or feldspathic sandstones. Using Al as an immobile element monitor, calculations show that the majority of tourmalinites in the region formed through the addition of moderate to significant amounts of B, Mg, Na, Sr, and Be, and the loss of moderate to significant Mn, Ca, K, P, Rb, Ba, and Cr; minor Si, Ti, V, light REE, and Eu also were lost. Data for relatively immobile Al, Zr, Th, Sc, Nb, and heavy REE indicate that, on average, these tourmalinites formed through similar to 12% net mass loss assuming an original conglomerate protolith, or through similar to 7% net mass loss assuming a sandstone protolith. The B and other introduced constituents in the tourmalinites were deposited by hydrothermal fluids focused along and near basement-cover decollements. These fluids, believed to be associated with late Hercynian felsic magmatism, probably are related to fluids that formed the tourmaline-rich U-Mo-Zn deposits at the nearby Novazza mine and the U-Zn deposits at the nearby Val Vedello mine. C1 UNIV MAINZ,INST GEOWISSENSCH TEKTONOPHYS,D-55099 MAINZ,GERMANY. STATE SEISMOL BUR,INST GEOL,BEIJING 100029,PEOPLES R CHINA. RP Slack, JF (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 954,RESTON,VA 22092, USA. NR 48 TC 6 Z9 6 U1 0 U2 3 PU STAUBLI VERLAG AG PI ZURICH PA POSTFACH 566, CH-8045 ZURICH, SWITZERLAND SN 0036-7699 J9 SCHWEIZ MINER PETROG JI Schweiz. Mineral. Petrogr. Mitt. PY 1996 VL 76 IS 2 BP 193 EP 207 PG 15 WC Geology; Mineralogy SC Geology; Mineralogy GA VC998 UT WOS:A1996VC99800006 ER PT S AU Osterkamp, WR Hupp, CR AF Osterkamp, WR Hupp, CR BE Rhoads, BL Thorn, CE TI The evolution of geomorphology, ecology, and other composite sciences SO SCIENTIFIC NATURE OF GEOMORPHOLOGY SE BINGHAMTON SYMPOSIA IN GEOMORPHOLOGY : INTERNATIONAL SERIES LA English DT Proceedings Paper CT 27th Binghamton Symposium in Geomorphology CY SEP 27-29, 1996 CL BINGHAMTON, NY AB Geomorphology, ecology, and related disciplines are complex composites of the basic sciences -physics, chemistry, and biology. The basic sciences have developed through paradigm (exemplar) definition and replacement, but the composite sciences, too complex to generate applicable exemplars, developed from principles borrowed from basic science. Succeeding periods of speculation and observation, composite sciences adopted exemplars of evolution from biology and equilibrium from chemistry. Effort continues to unite these conflicting approaches. Work of geomorphologists, ecologists, and other composite scientists suggests that periods of Darwinian evolution, equilibrium, and integration occurred in common sequence but with different timing in the composite sciences. Fundamental differences between the basic and composite sciences -simplicity versus complexity, suitability versus inappropriateness to direction by exemplars, and a generally theoretical versus applied quality -provide explanations for different patterns of development. Based on common characteristics and methods of investigation, future trends in composite science are anticipated. RP Osterkamp, WR (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 0 TC 15 Z9 15 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA BAFFINS LANE, CHICHESTER, WEST SUSSEX, ENGLAND PO19 1UD SN 0261-3174 BN 0-471-96811-0 J9 BING SYMP G PY 1996 BP 415 EP 441 PG 27 WC Geosciences, Multidisciplinary SC Geology GA BJ84P UT WOS:A1996BJ84P00017 ER PT J AU Humphrey, MD Istok, JD Flint, LE Flint, AL AF Humphrey, MD Istok, JD Flint, LE Flint, AL TI Improved method for measuring water imbibition rates on low-permeability porous media SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID SORPTIVITY AB Existing methods for measuring water imbibition rates are inadequate when imbibition rates are small (e.g., clay soils and many igneous rocks). We developed an improved laboratory method for performing imbibition measurements on soil or rock cores with a wide range of hydraulic properties, Core specimens are suspended from an electronic strain gauge (load cell) in a closed chamber while maintaining the lower end of the core in contact with a free water surface in a constant water level reservoir. The upper end of the core is open to the atmosphere. During imbibition, mass increase of the core is recorded continuously by a datalogger that converts the load cell voltage signal into mass units using a calibration curve. Computer automation allows imbibition rate measurement on as many as eight cores simultaneously and independently. Performance of each component of the imbibition apparatus was evaluated using a set of rock cores (2.5 cm in diameter and 2-5 cm in length) from a single lithostratigraphic unit composed of non-to-moderately welded ash-flow tuff (a glass-rich pyroclastic rock partially fused by heat and pressure) with porosities ranging from 0.094 to 0.533 m(3) m(-3). Reproducibility of sample handling and testing procedures was demonstrated using replicate measurements. Precision and accuracy of load cell measurements were assessed using mass balance calculations and indicated agreement within a few tenths of a percent of total mass, Computed values of sorptivity, S, ranged from 8.83 x 10(-6) to 4.55 x 10(-4) m s(-0.5). The developed method should prove useful for measuring imbibition rates on a wide range of porous materials. C1 US GEOL SURVEY,MERCURY,NV 89023. RP Humphrey, MD (reprint author), OREGON STATE UNIV,DEPT CIVIL ENGN,CORVALLIS,OR 97331, USA. NR 11 TC 2 Z9 2 U1 3 U2 4 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 1996 VL 60 IS 1 BP 28 EP 34 PG 7 WC Soil Science SC Agriculture GA TR434 UT WOS:A1996TR43400004 ER PT J AU Andraski, BJ AF Andraski, BJ TI Properties and variability of soil and trench fill at an arid waste-burial site SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID HYDRAULIC CONDUCTIVITY; DESERT SOIL AB Arid sites commonly are assumed to be ideal for long-term isolation of wastes. Information on properties and variability of desert soils is limited, however, and little is known about how the natural site environment is altered by installation of a waste facility. During fall construction of two test trenches next to the waste facility on the Amargosa Desert near Beatty, NV, samples were collected to: (i) characterize physical and hydraulic properties of native soil (upper 5 m) and trench fill, (ii) determine effects of trench construction on selected properties and vertical variability of these properties, and (iii) develop conceptual models of vertical variation within the soil profile and trench fill. Water retention was measured to air dryness (Psi = 2 x 10(6) cm water suction). The 15 300-cm pressure-plate data were omitted from the analysis because water-activity measurements showed the actual suction values were significantly less than the expected 15 300-cm value (avg. difference = 8550 +/- 2460 cm water). Trench construction significantly altered properties and variability of the natural site environment. For example, water content ranged from 0.029 to 0.041 m(3) m(-3) for fill vs. 0.030 to 0.095 m(3) m(-3) for soil; saturated hydraulic conductivity was approximate to 10(-4) cm s(-1) for fill vs. 10(-2) to approximate to 10(-4) cm s(-1) for soil. Statistical analyses showed that the native soil may be represented by three major horizontal components and the fill by a single component. Under initial conditions, calculated liquid conductivity (K-1) plus isothermal vapor conductivity (K-v) for the upper two soil layers and the trench fill was approximate to 10(-13) cm s(-1), and K-1 was less than or equal to K-v. For the deeper (2-5 m) soil, total conductivity was approximate to 10(-10) cm s(-1), and K-1 was > K-v. This study quantitatively describes hydraulic characteristics of a site using data measured across a water-content range that is representative of arid conditions, but is seldom studied. RP Andraski, BJ (reprint author), US GEOL SURVEY,333 N NYE LANE,CARSON CITY,NV 89706, USA. NR 33 TC 22 Z9 22 U1 0 U2 1 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 1996 VL 60 IS 1 BP 54 EP 66 PG 13 WC Soil Science SC Agriculture GA TR434 UT WOS:A1996TR43400008 ER PT J AU Vepraskas, MJ Guertal, WR Kleiss, HJ Amoozegar, A AF Vepraskas, MJ Guertal, WR Kleiss, HJ Amoozegar, A TI Porosity factors that control the hydraulic conductivity of soil-saprolite transitional zones SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID SEQUENCE AB Slowly permeable transitional horizons separate soil and saprolite, but these horizons cannot be identified easily in the field. The objectives of this study were to determine why the soil-saprolite transitional zone (BC and CB horizons) is slowly permeable, and to evaluate ways for identifying it in the field, Two saprolite deposits were studied in the North Carolina Piedmont. At each site, saturated and unsaturated hydraulic conductivities (K-sat and K-unsat) were measured for major horizons. Volume fractions of water-conducting pores were also compared with the changes in hydraulic conductivity with depth. Horizon mean K-sat values at both sites ranged from virtually 0 to approximately 3 cm h(-1). The lowest K-sat values (<0.3 cm h(-1)) occurred in or near the transitional horizons that were directly below the Bt horizons. Changes in the volume of pores within or between mineral grains (termed inter/intraparticle pores) with depth corresponded to changes in both K-sat and K-unsat. In the transitional horizons, the inter/intraparticle pores were plugged with clay and this caused the horizons to have low K values. In situ measurements of K-sat with depth were the most accurate technique to use for identifying transitional zones in the field. Examination of both the soil and rock structures in pits was also an acceptable technique. Texture and consistence were not considered reliable for pin-pointing transitional horizons. C1 US GEOL SURVEY,DIV WATER RESOURCES,YUCCA MT PROJECT BRANCH,MERCURY,NV. RP Vepraskas, MJ (reprint author), N CAROLINA STATE UNIV,DEPT SOIL SCI,RALEIGH,NC 27695, USA. NR 27 TC 15 Z9 16 U1 0 U2 1 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 1996 VL 60 IS 1 BP 192 EP 199 PG 8 WC Soil Science SC Agriculture GA TR434 UT WOS:A1996TR43400030 ER PT B AU Beauchamp, PM Alkalai, L Brown, RH Capps, RW Chen, GS Crisp, MP Cutts, JA Davidson, JM Petrick, SW Rodgers, DH Vane, G AF Beauchamp, PM Alkalai, L Brown, RH Capps, RW Chen, GS Crisp, MP Cutts, JA Davidson, JM Petrick, SW Rodgers, DH Vane, G BE Casani, EK VanderDoes, MA TI The sciencecraft process SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 22 EP 30 DI 10.1117/12.255135 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00003 ER PT B AU Wahl, KL Miller, JE AF Wahl, KL Miller, JE BE Tickle, KS Goulter, IC Xu, CC Wasimi, SA Bouchart, F TI The occurrence of critical and supercritical velocities in natural channels SO STOCHASTIC HYDRAULICS '96 LA English DT Proceedings Paper CT 7th IAHR International Symposium on Stochastic Hydraulics CY JUL 29-31, 1996 CL MACKAY, AUSTRALIA SP IAHR, Cent Queensland Univ, Ctr Land & Water Dev, Inst Engineers, Australia, Mackay Branch C1 US GEOL SURVEY,LAKEWOOD,CO 80225. NR 0 TC 1 Z9 1 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-817-7 PY 1996 BP 561 EP 568 PG 8 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA BF88T UT WOS:A1996BF88T00073 ER PT S AU Williams, JH Morrissey, DJ AF Williams, JH Morrissey, DJ BE Ritchey, JD Rumbaugh, JO TI Recharge of valley-fill aquifers in the glaciated northeast from upland runoff SO SUBSURFACE FLUID-FLOW (GROUND-WATER AND VADOSE ZONE) MODELING SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Subsurface Fluid Flow (Groundwater) Modeling CY JUN 22-23, 1996 CL DENVER, CO DE aquifers; recharge; stream infiltration; ground-water flow model C1 US GEOL SURVEY,TROY,NY 12180. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 SN 1071-5827 BN 0-8031-2021-4 J9 AM SOC TEST MATER PY 1996 VL 1288 BP 97 EP 113 DI 10.1520/STP38381S PG 17 WC Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA BG48P UT WOS:A1996BG48P00007 ER PT B AU Allerton, DK Desborough, GA Olsen, HW Chang, NY AF Allerton, DK Desborough, GA Olsen, HW Chang, NY BE Nelson, JD TI Waste containment barrier enhancement with zeolite SO TAILINGS AND MINE WASTE '96 LA English DT Proceedings Paper CT 3rd International Conference on Tailings and Mine Waste 96 CY JAN 16-19, 1996 CL FT COLLINS, CO C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 2 Z9 2 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-594-1 PY 1996 BP 255 EP 264 PG 10 WC Engineering, Environmental; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA BE97K UT WOS:A1996BE97K00028 ER PT J AU Rabbel, W Mooney, WD AF Rabbel, W Mooney, WD TI Seismic anisotropy of the crystalline crust: What does it tell us? SO TERRA NOVA LA English DT Article ID SOUTHWEST GERMANY; UPPER-MANTLE; BENEATH AB The study of the directional dependence of seismic velocities (seismic anisotropy) promises more refined insight into mineral composition and physical properties of the crystalline crust than conventional deep seismic refraction or reflection profiles providing average values of P- and S-wave velocities. The alignment of specific minerals by ductile rock deformation, for instance, causes specific types of seismic anisotropy which can be identified by appropriate field measurements. Vice versa, the determination of anisotropy can help to discriminate between different rock candidates in the deep crust. Seismic field measurements at the Continental Deep Drilling Site (KTB, S Germany) are shown as an example that anisotropy has to be considered in crustal studies. At the KTB, the dependence of seismic velocity on the direction of wave propagation in situ was found to be compatible with the texture, composition and fracture density of drilled crustal rocks. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Rabbel, W (reprint author), CHRISTIAN ALBRECHTS UNIV KIEL,INST GEOPHYS,OLSHAUSENSTR 40-60,D-24098 KIEL,GERMANY. NR 37 TC 24 Z9 28 U1 0 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0954-4879 J9 TERRA NOVA JI Terr. Nova PY 1996 VL 8 IS 1 BP 16 EP 21 DI 10.1111/j.1365-3121.1996.tb00721.x PG 6 WC Geosciences, Multidisciplinary SC Geology GA UG249 UT WOS:A1996UG24900004 ER PT J AU Quinn, TP Peterson, NP Spalding, S AF Quinn, TP Peterson, NP Spalding, S TI Effects of instream brush on juvenile coho salmon: Response SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID CUTTHROAT TROUT; GROWTH C1 SIMPSON TIMBER CO, SHELTON, WA 98584 USA. US FISH & WILDLIFE SERV, OLYMPIA, WA 98501 USA. RP Quinn, TP (reprint author), UNIV WASHINGTON, SCH FISHERIES, BOX 357980, SEATTLE, WA 98195 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JAN PY 1996 VL 125 IS 1 BP 151 EP 153 DI 10.1577/1548-8659-125.1.151 PG 3 WC Fisheries SC Fisheries GA TP350 UT WOS:A1996TP35000019 ER PT J AU Lowenstern, JB Sinclair, WD AF Lowenstern, JB Sinclair, WD TI Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the cretaceous logtung W-Mo deposit, Yukon territory, Canada SO TRANSACTIONS OF THE ROYAL SOCIETY OF EDINBURGH-EARTH SCIENCES LA English DT Article; Proceedings Paper CT 3rd Hutton Symposium on the Origin of Granites and Related Rocks CY AUG 27-SEP 02, 1995 CL UNIV MARYLAND COLL PK, COLLEGE PK, MD SP Univ Maryland Coll Pk, Dept Geol, US Geol Survey, Reston, Carnegie Inst Washington, Dept Terrestrial Magnetism & Geophys Lab HO UNIV MARYLAND COLL PK DE volatiles; magma; degassing; comb quartz; comb layering; unidirectional solidification textures; Mo; W; porphyry; infra-red; FTIR; trace elements ID HYDROGEN SPECIATION; GRANITIC PEGMATITES; CRYSTALLIZATION; GEOTHERMOMETER; MINERALS; COLORADO; WATER; MODEL; ROCKS AB Comb-layered quartz is a type of unidirectional solidification texture found at the roofs of shallow silicic intrusions that are often associated spatially with Mo and W mineralisation. The texture consists of multiple layers of euhedral, prismatic quartz crystals (Type I) that have grown on subplanar aplite substrates. The layers are separated by porphyritic aplite containing equant phenocrysts of quartz (Type II), which resemble quartz typical of volcanic rocks and porphyry intrusions. At Logtung, Type I quartz within comb layers is zoned with respect to a number of trace elements, including Al and K. Concentrations of these elements as well as Mn, Ti, Ge, Rb and H are anomalous and much higher than found in Type II quartz From Logtung or in igneous quartz reported elsewhere. The two populations appear to have formed under different conditions. The Type II quartz phenocrysts almost certainly grew from a high-silica melt between 600 and 800 degrees C (as beta-quartz), in contrast, the morphology of Type I quartz is consistent with precipitation from a hydrothermal solution, possibly as alpha-quartz grown below 600 degrees C. The bulk compositions of comb-layered rocks, as well as the aplite interlayers, are consistent with the hypothesis that these textures did not precipitate solely from a crystallising silicate melt. Instead, Type I quartz may have grown from pockets of exsolved magmatic fluid located between the magma and its crystallised border. The Type II quartz represents pre-existing phenocrysts in the underlying magma; this magma was quenched to aplite during fracturing/degassing events. Renewed and repeated formation and disruption of the peckers of exsolved aqueous fluid accounts for the rhythmic banding of the rocks. RP Lowenstern, JB (reprint author), US GEOL SURVEY,MAIL STOP 910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. OI Lowenstern, Jacob/0000-0003-0464-7779 NR 51 TC 39 Z9 43 U1 2 U2 8 PU ROYAL SOC EDINBURGH PI EDINBURGH PA 22-24 GEORGE ST, EDINBURGH, MIDLOTHIAN, SCOTLAND EH2 2PQ SN 0263-5933 J9 T ROY SOC EDIN-EARTH JI Trans. R. Soc. Edinb.-Earth Sci. PY 1996 VL 87 BP 291 EP 303 PN 1-2 PG 13 WC Geosciences, Multidisciplinary; Paleontology SC Geology; Paleontology GA VH759 UT WOS:A1996VH75900029 ER PT S AU Reynolds, RE Cohan, DR Johnson, MA AF Reynolds, RE Cohan, DR Johnson, MA BE Wadsworth, KG McCabe, RE TI Using landscape information approaches to increase duck recruitment in the prairie pothole region SO TRANSACTIONS OF THE SIXTY-FIRST NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE SE TRANSACTIONS OF THE NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE LA English DT Proceedings Paper CT 61st North-American Wildlife and Natural Resources Conference on Facing Realities in Resource Management CY MAR 22-27, 1996 CL TULSA, OK RP Reynolds, RE (reprint author), US FISH & WILDLIFE SERV,BISMARCK,ND, USA. NR 0 TC 19 Z9 20 U1 1 U2 2 PU WILDLIFE MANAGEMENT INSTITUTE PI WASHINGTON PA 1101 14TH STREET NW, SUITE 801, WASHINGTON, DC 20005 SN 0078-1355 J9 T N AM WILDL NAT RES PY 1996 BP 86 EP 93 PG 8 WC Ecology; Fisheries; Forestry; Ornithology; Zoology SC Environmental Sciences & Ecology; Fisheries; Forestry; Zoology GA BG62W UT WOS:A1996BG62W00010 ER PT J AU Angus, SF AF Angus, SF BE Wadsworth, KG McCabe, RE TI Diversity: Maintenance tips for a double-edged sword SO TRANSACTIONS OF THE SIXTY-FIRST NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE SE TRANSACTIONS OF THE NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE LA English DT Proceedings Paper CT 61st North-American Wildlife and Natural Resources Conference on Facing Realities in Resource Management CY MAR 22-27, 1996 CL TULSA, OK RP Angus, SF (reprint author), US FISH & WILDLIFE SERV,MANAGEMENT ASSISTANCE TEAM,FT COLLINS,CO, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILDLIFE MANAGEMENT INSTITUTE PI WASHINGTON PA 1101 14TH STREET NW, SUITE 801, WASHINGTON, DC 20005 SN 0078-1355 J9 T N AM WILDL NAT RES PY 1996 BP 162 EP 167 PG 6 WC Ecology; Fisheries; Forestry; Ornithology; Zoology SC Environmental Sciences & Ecology; Fisheries; Forestry; Zoology GA BG62W UT WOS:A1996BG62W00020 ER PT S AU Amend, SR Gasson, W AF Amend, SR Gasson, W BE Wadsworth, KG McCabe, RE TI Beyond rhetoric: Facing the new realities in fish and wildlife agency management SO TRANSACTIONS OF THE SIXTY-FIRST NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE SE TRANSACTIONS OF THE NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE LA English DT Proceedings Paper CT 61st North-American Wildlife and Natural Resources Conference on Facing Realities in Resource Management CY MAR 22-27, 1996 CL TULSA, OK RP Amend, SR (reprint author), US FISH & WILDLIFE SERV,FT COLLINS,CO, USA. NR 0 TC 7 Z9 7 U1 0 U2 1 PU WILDLIFE MANAGEMENT INSTITUTE PI WASHINGTON PA 1101 14TH STREET NW, SUITE 801, WASHINGTON, DC 20005 SN 0078-1355 J9 T N AM WILDL NAT RES PY 1996 BP 168 EP 176 PG 9 WC Ecology; Fisheries; Forestry; Ornithology; Zoology SC Environmental Sciences & Ecology; Fisheries; Forestry; Zoology GA BG62W UT WOS:A1996BG62W00021 ER PT S AU Rasmussen, JL AF Rasmussen, JL BE Wadsworth, KG McCabe, RE TI MICRA - From dream to reality SO TRANSACTIONS OF THE SIXTY-FIRST NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE SE TRANSACTIONS OF THE NORTH AMERICAN WILDLIFE AND NATURAL RESOURCES CONFERENCE LA English DT Proceedings Paper CT 61st North-American Wildlife and Natural Resources Conference on Facing Realities in Resource Management CY MAR 22-27, 1996 CL TULSA, OK RP Rasmussen, JL (reprint author), US FISH & WILDLIFE SERV,BETTENDORF,IA 52722, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILDLIFE MANAGEMENT INSTITUTE PI WASHINGTON PA 1101 14TH STREET NW, SUITE 801, WASHINGTON, DC 20005 SN 0078-1355 J9 T N AM WILDL NAT RES PY 1996 BP 534 EP 539 PG 6 WC Ecology; Fisheries; Forestry; Ornithology; Zoology SC Environmental Sciences & Ecology; Fisheries; Forestry; Zoology GA BG62W UT WOS:A1996BG62W00064 ER PT B AU VonThun, JL AF VonThun, JL BE Shackelford, CD Nelson, PP Roth, MJS TI Risk assessment of Nambe Falls Dam SO UNCERTAINTY IN THE GEOLOGIC ENVIRONMENT: FROM THEORY TO PRACTICE, VOLS 1 AND 2: PROCEEDINGS OF UNCERTAINTY '96 SE GEOTECHNICAL SPECIAL PUBLICATION LA English DT Proceedings Paper CT ASCE Geotechnical-Engineering-Division Specialty Conference on Uncertainty in the Geologic Environment - From Theory to Practice (UNCERTAINTY 96) CY JUL 31-AUG 03, 1996 CL MADISON, WI SP Amer Soc Civil Engineers, Geotech Engn Div, ASFE, Profess Firms Practicing Geosci, Amer Soc Testing & Mat, Comm D 18, Natl Sci Fdn, US Dept Transportat, Fed Highway Adm, US EPA C1 US GEOL SURVEY,DENVER FED CTR,RECLAMAT SERV CTR,BUR RECLAMAT,DENVER,CO 80225. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 BN 0-7844-0188-8 J9 GEOTECH SP PY 1996 IS 58 BP 604 EP 635 PG 32 WC Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA BG40S UT WOS:A1996BG40S00036 ER PT B AU Carter, V AF Carter, V BE Warner, BG McBean, EA TI Environmental gradients, boundaries, and buffers: An overview SO WETLANDS: ENVIRONMENTAL GRADIENTS, BOUNDARIES, AND BUFFERS LA English DT Proceedings Paper CT International Symposium on Wetlands - Environmental Gradients, Boundaries, and Buffers CY APR 22-23, 1994 CL WATERLOO, CANADA SP Univ Waterloo, Wetlands Res Ctr, Univ Waterloo, Fac Engn Environm Studies & Sci RP Carter, V (reprint author), US GEOL SURVEY,430 NATL CTR,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. NR 0 TC 3 Z9 3 U1 0 U2 2 PU LEWIS PUBLISHERS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, BOCA RATON, FL 33431 BN 1-56670-147-3 PY 1996 BP 9 EP 17 PG 9 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA BG92L UT WOS:A1996BG92L00002 ER PT B AU Tiner, RW AF Tiner, RW BE Warner, BG McBean, EA TI Practical considerations for wetland identification and boundary delineation SO WETLANDS: ENVIRONMENTAL GRADIENTS, BOUNDARIES, AND BUFFERS LA English DT Proceedings Paper CT International Symposium on Wetlands - Environmental Gradients, Boundaries, and Buffers CY APR 22-23, 1994 CL WATERLOO, CANADA SP Univ Waterloo, Wetlands Res Ctr, Univ Waterloo, Fac Engn Environm Studies & Sci AB Since the 1970s, the federal government in the United States has been increasingly more active in regulating construction in wetlands. During this time many states have similarly developed programs to control development in wetlands. These regulations have necessitated the establishment of standardized procedures to identify and delineate wetlands. These methods utilize one or more types of wetland indicators, including hydrophytic vegetation, hydric soils, and other indicators of periodic wetness associated with wetlands. Several methods have been used for wetland identification: (1) vegetation-based methods, (2) soil-based methods, (3) three-parameter methods (using plants, soils, and other signs of wetland hydrology), and (4) the primary indicators method (relying on unique features to indicate wetlands). This article reviews wetland indicators and bow they have been used in these methods to identify and delineate wetlands. Wetland mapping is also discussed. Recommendations are offered on how to improve identification of wetlands for regulatory purposes. RP Tiner, RW (reprint author), US FISH & WILDLIFE SERV,300 WESTGATE CTR DR,HADLEY,MA 01035, USA. NR 0 TC 3 Z9 3 U1 0 U2 3 PU LEWIS PUBLISHERS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, BOCA RATON, FL 33431 BN 1-56670-147-3 PY 1996 BP 113 EP 137 PG 25 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA BG92L UT WOS:A1996BG92L00008 ER PT J AU Gilbert, DW Anderson, DR Ringelman, JK Szymczak, MR AF Gilbert, DW Anderson, DR Ringelman, JK Szymczak, MR TI Response of nesting ducks to habitat and management on the Monte Vista National Wildlife Refuge, Colorado SO WILDLIFE MONOGRAPHS LA English DT Review DE biomonitoring; grazing; line-transect sampling; nest density; nest success; refuge management; waterfowl ID NORTH-DAKOTA; CROW PREDATION; CLUTCH SIZE; SUCCESS; COVER; MALLARDS; PINTAILS; GADWALL; ALBERTA; ECOLOGY AB We analyzed duck nesting data from the Monte Vista National Wildlife Refuge (MVNWR) in the San Luis Valley (SLV) of Colorado to evaluate the influence of habitat and management on nest density and success. From 1964 to 1990 (except 1977), 4,154 duck nests were found on 16,159 km (10,041 miles) of transect. Strip transects were searched twice annually, with a follow-up visit to nest sites to determine nest fate. During 1964-68, 521 km (324 miles) of transect were searched (142 transects) twice each year, but this was reduced by half during 1969-90 (71 transects). We evaluated information on duck nests in 22 of 24 refuge management units. Mallards (Anas platyrhynchos) composed 54.5% of the duck nests on MVNWR, followed in abundance by teal species (A. cyanoptera, A, discors, A. crecca) and northern pintails (A, acuta). Refuge nest densities ranged from a low of 36 nests/km(2) (93 nests/mi(2)) in 1979 to a high of 161 nests/km(2) (418 nests/mi(2)) in 1973. Over the 26-year period (1964-90), 52.4% of 4,154 nests were successful. Apparent annual nest success averaged 49.4% and ranged from 27% in 1978 to 72% in 1966. Nest failure resulted from predation (25.8% of total nests), desertion (10.6%), flooding (4.9%), or-unknown causes (10.8%). It was not possible to directly estimate true nest success, but indirect methods suggest that true nest success was 60 to 90% that of apparent nest success. Nest success rates were similar among species. Baltic rush (Juncus balticus) was the most common vegetation on the refuge, followed in abundance by black greasewood (Sarcobatus vermiculatus), inland saltgrass (Distichlis stricta), and other grass species. Stands of common cattail (Typha latifolia), miscellaneous herbaceous vegetation, and Baltic rush were preferred nesting cover, whereas greasewood and saltgrass generally were avoided. Nest density declined (P = 0.037) with increasing grazing intensity, with large (38%) declines apparent the first season after only light grazing (0.2 animal unit month/ha [0.5 AUM/acre]). Three years after grazing, nest density was still depressed at least 17% below estimated pregrazing levels. In addition, nest success declined as grazing intensity increased (P = 0.070). Duck nesting densities on the MVNWR are among the highest reported in North America. High duck production can be maintained by applying water in late March; reducing the frequency of grazing and burning treatments; and developing wetland management units to achieve their potential. C1 COLORADO STATE UNIV,US FISH & WILDLIFE SERV,COLORADO COOPERAT FISH & WILDLIFE RES UNIT,FT COLLINS,CO 80523. COLORADO STATE UNIV,DEPT FISHERY & WILDLIFE BIOL,FT COLLINS,CO 80523. COLORADO DIV WILDLIFE,WILDLIFE RES CTR,FT COLLINS,CO 80526. NR 107 TC 0 Z9 0 U1 1 U2 8 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0084-0173 J9 WILDLIFE MONOGR JI Wildl. Monogr. PD JAN PY 1996 IS 131 BP 5 EP 44 PG 40 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA TU168 UT WOS:A1996TU16800001 ER PT J AU Bove, DJ Ratte, JC McIntosh, WC Snee, LW Futa, K AF Bove, DJ Ratte, JC McIntosh, WC Snee, LW Futa, K TI The evolution of the Eagle Peak Volcano - A distinctive phase of Middle Miocene volcanism in the western Mogollon Datil volcanic field, New Mexico SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID SOUTHWESTERN NEW-MEXICO; CHEMICAL CLASSIFICATION; NORTH-AMERICA; ROCKS; ELEMENTS; DIAGRAM; BASALT; MAGMAS; LAVAS AB The andesitic to dacitic Eagle Peak volcano represents a distinctive phase of Middle Miocene, post-caldera volcanism in the western part of the Mogollon-Datil volcanic field in southwestern New Mexico. Erupted during Basin and Range extensional tectonism, rocks of the Eagle Peak volcano are chemically and isotopically distinct from the bimodal suite, extension-related basalt and rhyolite that also erupted in this area from the Early Miocene to the Pleistocene. Instead, they have close petrogenetic affinities to the early post-caldera (similar to 27-23 Ma) calc-alkaline, Bearwallow Mountain Andesite erupted from shield volcanos aligned along prominent Basin and Range fault structures. Geologic mapping and detailed petrographic and chemical studies of the Eagle Peak volcano has enabled the distinction of five different flow units, a central plug and a feeder dike. The flows were erupted from a central vent and two subsidiary ''satellitic'' centers on the western and southwestern flanks of the volcano. Ar-40/Ar-39 age-spectrum and paleomagnetic studies indicate that the Eagle Peak volcano was active between 12.1 and 11.4 Ma; its activity spanned at least one magnetic polarity reversal. With exception of late satellitic eruptions on the northwestern margin of the volcano, central vent and satellitic flows were erupted in rapid succession and have an average age of 11.7 Ma. The central plug yielded a plateau age of 11.4 Ma, which is a minimum of 90,000 years (2 sigma) younger than the 11.7 Ma average age of the central vent and satellitic flows. Major-oxide, trace-element and isotope geochemistry define two distinct magmatic series: a central vent and a satellitic series. Rocks of the satellitic series, although similar in modal mineralogy and rare earth element patterns, are slightly more alkaline and relatively enriched in the high field strength elements Nb, Ta, P and Ti compared to the central vent eruptives. Sr and Nd isotopes further demonstrate these differences; a sample of the satellitic flows exhibits lower (Sr-87/Sr-86)(i)(0.7084) and higher epsilon(Nd) values (epsilon(Nd)=-4.8) relative to an upper flow of the central vent series [(Sr-87/Sr-86)(i)=0.7096), epsilon(Nd)=-8.5]. Major- and trace-element data support petrogenetic models based on periodic tapping of the central vent and satellitic series magmas, which both evolved by crystal fractionation. Central vent magmas evolved mainly by a modified process of filter pressing that accompanied the transfer of magma from a deep into a higher-level reservoir. Thus, a portion of the melt with some of the original crystals was extracted during this transer changing the resulting bulk magma chemistry but not affecting the major phenocryst compositions. In contrast, crystal fractionation within the satellitic magmas accompanied a progressive evolution in both phenocryst composition and bulk magma chemistry. Although temporally associated with bimodal basalt-rhyolite volcanism (<21 Ma to Holocene), Eagle Peak rocks differ markedly from the suite of mafic bimodal rocks in trace-element and Sr and Nd isotope chemistry. Mafic rocks of the bimodal suite have Sr and Nd isotopic initial ratios that range from depleted mantle to bulk earth values [(Sr-87/Sr-86)i=0.7030-0.7057, epsilon(Nd) = 0 to +9.12], and are substantially more primitive than Eagle Peak rocks [(Sr-87/Sr-86)i=0.70839-0.70958, epsilon(Nd)=-8.4 to -4.9]. In contrast, Eagle Peak volcanics are geochemically more similar to the 27-23 Ma post-caldera Bearwallow Mountain Andesite, which is characterized by (Sr-87/Sr-86)i=0.7070-0.7102 and epsilon(Nd)=-8.15 to -5.95. The Eagle Peak volcanics, like the Bearwallow Mountain Andesite, assimilated a significant component of crustal material and were both likely derived from a similar lithospheric mantle source beneath the western Mogollon-Datil volcanic field. C1 NEW MEXICO BUR MINES & MINERAL RESOURCES,SOCORRO,NM 87801. RP Bove, DJ (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 905,DENVER,CO 80225, USA. NR 49 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC 30 PY 1995 VL 69 IS 3-4 BP 159 EP 186 DI 10.1016/0377-0273(95)00031-3 PG 28 WC Geosciences, Multidisciplinary SC Geology GA TX469 UT WOS:A1995TX46900002 ER PT J AU Duffield, WA Ruiz, J Webster, JD AF Duffield, WA Ruiz, J Webster, JD TI Roof rock contamination of magma along the top of the reservoir for the Bishop Tuff SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID TAYLOR CREEK RHYOLITE; LONG VALLEY CALDERA; SILICIC MAGMA; NEW-MEXICO; LAVA DOMES; CALIFORNIA; SR; GRADIENTS; CHAMBERS; CRYSTALLIZATION AB The Bishop Tuff, a well known Quaternary high-silica rhyolite in east-central California, is widely considered the type example of a vertically and monotonically zoned pyroclastic deposit that represents zoning in the source magma reservoir, inverted during the process of pyroclastic emplacement. However, the deposit of plinian pumice, which forms the base of the Bishop Tuff and represents the initial 10% or so of all magma erupted during the event that produced the Bishop Tuff, contains features at odds with monotonic zoning for the reservoir, Relative to overlying ignimbrite, the plinian deposit contains a reversal in trace-element zoning. Moreover, the Sr-87/Sr-86 is significantly higher than that in overlying ignimbrite (about 0.7084 vs 0.7064), and melt inclusions trapped in quartz phenocrysts exhibit notable variability of trace-element concentrations, even within a single host crystal (e.g., U:10.77 to 8.91 ppm). These data have been previously interpreted as due to processes of chemical fractionation and evolution operating within a magma system closed to chemical interactions with its roof rocks. For example, the reversal in trace-element zoning has been explained by the first-erupted magma being erupted from somewhat below the top of a monotonically zoned reservoir. However, we submit that the reversed zoning and other above-noted features can be explained equally well as consequences of minor assimilation of roof rocks into a magma reservoir that was erupted from the top down. The basal part of the Bishop Tuff exhibits extreme concentrations and depletions of trace elements, relative to the average composition of crustal rocks. For example, the upward decrease of Sr in the Bishop magma reservoir (downward decrease in the ignimbrite) results in concentrations as low as 2-4 ppm, Because of the attendant 'chemical leverage', assimilation of <1 wt.% of Sierra Nevada bathorith racks typical of the area could readily reverse an 'uncontaminated' Sr (and other trace elements) trend of zoning and could also substantially raise Sr-87/Sr-86. Small-scale trace-element variability in the uppermost part of the Bishop magma reservoir, as recorded by the above-mentioned melt inclusions, may simply reflect melt heterogeneity produced by the process of assimilation. C1 UNIV ARIZONA, DEPT GEOSCI, TUCSON, AZ 85721 USA. AMER MUSEUM NAT HIST, DEPT MINERAL SCI, NEW YORK, NY 10024 USA. RP Duffield, WA (reprint author), US GEOL SURVEY, 2255 N GEMINI DR, FLAGSTAFF, AZ 86001 USA. NR 25 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 EI 1872-6097 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC 30 PY 1995 VL 69 IS 3-4 BP 187 EP 195 DI 10.1016/0377-0273(95)00026-7 PG 9 WC Geosciences, Multidisciplinary SC Geology GA TX469 UT WOS:A1995TX46900003 ER PT J AU Walker, GPL Eyre, PR AF Walker, GPL Eyre, PR TI Dike complexes in American Samoa SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID VOLCANISM; HAWAII AB Coherent dike complexes in which dikes make up more than 50% of the total rock occur in American Samoa in two volcanoes on Tutuila and in Ofu-Olosega volcano in the Manu'a Islands, The dikes are remarkably narrow (median width 0.24-0.36 m; average width 0.46-0.56 m, based on 860 measured dikes), significantly narrower than dikes in the Koolau volcano (Oahu, Hawaii), the most closely comparable volcano for which quantitative data are available. The vesicularity of these narrow dikes indicates that they were injected at shallow depths below the land surface: depths of 200-900 m are inferred from the topography. Many dikes have prominent bands of vesicles parallel with their margins. They tend to form clusters where the weakness of the vesicular rock favored center injection of one dike up the center of another, Examples are found of center injection repeated up to eight times. Local breccias, often composed largely of dike fragments evidently brecciated in situ, occur where irregular dikes were accommodated by deforming the host rocks. We see evidence for two dike facies: (1) narrow and vesicle banded, early formed and shallow-injected ''clustered'' dikes in the dike complexes, which are cut by (2) scattered broad and almost nonvesicular deep-injected ''solitary'' dikes. Surface eruptions were fed by solitary dikes. The ENE-trending dikes and elongation of Tutuila Island contrast with the WNW trend of rift zones and island elongation elsewhere in Samoa. Tutuila is nearly in line with the North Fiji transform fracture zone suggesting that at 1.5-1.0 Ma, when Tutuila was formed, the volcanism of Tutuila was guided by a temporary extension of this fault zone into the Pacific Plate. Fault movement offset the Samoan hotspot trace by 45 km. The en-echelon arrangement of dike exposures on Tutuila is consistent with left-lateral transcurrent motion above this concealed fracture zone. C1 US GEOL SURVEY,DIV WATER RESOURCES,HONOLULU,HI 96813. RP Walker, GPL (reprint author), UNIV HAWAII,DEPT GEOL & GEOPHYS,SOEST,HONOLULU,HI 96822, USA. NR 29 TC 22 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC 30 PY 1995 VL 69 IS 3-4 BP 241 EP 254 DI 10.1016/0377-0273(95)00041-0 PG 14 WC Geosciences, Multidisciplinary SC Geology GA TX469 UT WOS:A1995TX46900006 ER PT J AU Gaddis, LR McEwen, AS Becker, TL AF Gaddis, LR McEwen, AS Becker, TL TI Compositional variations on the Moon: Recalibration of Galileo solid-state imaging data for the Orientale region and farside SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID LUNAR IMPACT BASINS; WESTERN LIMB; FLYBY AB Updated radiometric calibration and systematic processing procedures for Galileo solid-state imaging (SSI) data from the first(1990) Earth-Moon encounter are presented. These procedures were applied to a whole-disk imaging sequence of the Moon centered near Mare Orientale, called Lunmap 14 (L14). Processing of L14 data included radiometric calibration, subpixel coregistration, scattered light removal, geometric control and reprojection, photometric normalization, and calibration to Earth-based spectra. Coregistration and scattered-light removal procedures are improvements over the initial calibration of the SSI mosaics. The effects of scattered light correction are best seen using a whole-Moon view such as L14; resolution of the debated amounts of light scattering from within or outside the camera field of view is not necessary. Scattered light removal particularly affects the 1-mu m spectral region and has implications for interpretation of mafic mineral signatures in mare deposits of the lunar limb and farside. Recalibrated spectra indicate that mare ponds of the limb show moderately deep 1-mu m absorptions, and thus mafic mineral contents, comparable to those of other nearside basalts. Mafic mineral contents of Schiller-Shickard cryptomaria are higher than previously thought and are similar to some low-Ti nearside basalts. Many of the recalibrated spectra from South Pole/Aitken are similar to those of Schiller-Schickard cryptomaria, suggesting that many of these soils represent a mixed mare/highland lithology, The hypothesis that there is an olivine enrichment in southern South Pole/Aitken basin is not supported strongly by spectra shown here. RP US GEOL SURVEY, 2255 N GEMINI DR, FLAGSTAFF, AZ 86001 USA. NR 22 TC 22 Z9 22 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26345 EP 26355 DI 10.1029/95JE03102 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700007 ER PT J AU SMITH, FA BETANCOURT, JL BROWN, JH AF SMITH, FA BETANCOURT, JL BROWN, JH TI EVOLUTION OF BODY-SIZE IN THE WOODRAT OVER THE PAST 25,000 YEARS OF CLIMATE-CHANGE SO SCIENCE LA English DT Article ID VEGETATION; RESPONSES; MEXICO AB Microevolutionary changes in the body size of the bushy-tailed woodrat (Neotoma cinerea) since the last glacial maximum were estimated from measurements of fecal pellets preserved in paleomiddens from the Great Basin and Colorado Plateau of the United States. The changes closely track regional temperature fluctuations simulated by the Community Climate Model of the National Center for Atmospheric Research and also those estimated from deuterium isotope ratios of plant cellulose recovered from paleomiddens. Body size decreased during periods of climatic warming, as predicted from Bergmann's rule and from physiological responses to temperature stress. Fossil woodrat middens, by providing detailed temporal sequences of body sizes from many locations, permit precise quantification of responses to climatic change that have occurred in the past and may occur in the future. C1 US GEOL SURVEY, DESERT LAB, TUCSON, AZ 85745 USA. RP UNIV NEW MEXICO, DEPT BIOL, ALBUQUERQUE, NM 87131 USA. NR 46 TC 135 Z9 135 U1 6 U2 48 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD DEC 22 PY 1995 VL 270 IS 5244 BP 2012 EP 2014 DI 10.1126/science.270.5244.2012 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TL420 UT WOS:A1995TL42000048 ER PT J AU COLMAN, SM PECK, JA KARABANOV, EB CARTER, SJ BRADBURY, JP KING, JW WILLIAMS, DF AF COLMAN, SM PECK, JA KARABANOV, EB CARTER, SJ BRADBURY, JP KING, JW WILLIAMS, DF TI CONTINENTAL CLIMATE RESPONSE TO ORBITAL FORCING FROM BIOGENIC SILICA RECORDS IN LAKE BAIKAL SO NATURE LA English DT Article ID CHINESE LOESS; ICE AGES; HOLOCENE; MICHIGAN AB CHANGES in insolation caused by periodic changes in the Earth's orbital parameters provide the primary forcing for global ice ages(1-6). But it is not clear to what extent the climates in continental interiors are controlled directly by regional variations in insolation and to what extent they are driven instead by the highly nonlinear response of the oceans and ice sheets, Here we investigate this question using the record of biogenic silica in Lake Baikal as a proxy for climate change in this high-latitude mid-continental region, We find a good correlation between this record and that of marine oxygen isotopes(4). Over the past 250 kyr the Baikal record exhibits both a strongly nonlinear component (manifested in a 100-kyr periodicity) and weaker direct-insolation components (manifested in the 41-kyr (obliquity) and 23- and 19-kyr (precession) orbital cycles). These results show that even though extreme continental climates such as this are influenced directly by insolation variations, they are dominated by the nonlinear rhythm of the oceans and ice sheets. C1 UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. UNIV S CAROLINA,DEPT GEOL SCI,COLUMBIA,SC 29209. US GEOL SURVEY,DENVER,CO 80225. RP COLMAN, SM (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. NR 32 TC 207 Z9 233 U1 3 U2 25 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD DEC 21 PY 1995 VL 378 IS 6559 BP 769 EP 771 DI 10.1038/378769a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TL419 UT WOS:A1995TL41900022 ER PT J AU Price, LC AF Price, LC TI Origins, characteristics, controls, and economic viabilities of deep-basin gas resources SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on Sources of Natural Gases, at the American-Chemical-Society Meeting CY AUG, 1993 CL CHICAGO, IL SP Amer Chem Soc ID NATURAL GASES; VITRINITE REFLECTANCE; ORGANIC GEOCHEMISTRY; SOURCE-ROCK; GENERATION; PRESSURE; OIL; HYDROCARBONS; MATURATION; STABILITY AB Dry-gas deposits (methane greater than or equal to 95% of the hydrocarbon (HC) gases) are thought to originate from in-reservoir thermal cracking of oil and C-2+ HC gases to methane. However, because methanes from Anadarko Basin dry-gas deposits do not carry the isotopic signature characteristic of C-15+ HC destruction, an origin of these methanes from this process is considered improbable. Instead, the isotopic signature of these methanes suggests that they were cogenerated with C-15+ HC's. Other gas-composition data from both nature and laboratory experiments also suggest that most methane in dry-gas deposits originates from a post-expulsion fractionation of wet gases generated with C-15+ HC's into methane-rich deposits. Only a limited resource of deep-basin gas deposits may be expected by the accepted model for the origin of dry-gas deposits because of a limited number of deep-basin oil deposits originally available to be thermally converted to dry gas. However, by the models of this paper (inefficient source-rock oil and gas expulsion, closed fluid systems in petroleum-basin depocenters, and most dry-gas methane cogenerated with C-15+ HC's), very large, previously unrecognized, unconventional, deep-basin gas resources are expected. Nonetheless, economic recovery of these gas resources will depend on drilling, completion, stimulation, production, and maintenance procedures applicable to the unique characteristics of each unconventional gas-resource base. Isotopic values of methanes from nature and laboratory experiments suggest that most 'thermogenic' methanes with delta(13)C values of -50 to -45 may have a significant component of biogenic methane. Also, laboratory experiments demonstrate that organic-matter facies variations have as strong a control on HC gas chemical and isotopic values as maturity. Thus, estimation of gas maturities by gas isotopic or chemical characteristics can be misleading. RP Price, LC (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 940,BOX 25046,DENVER,CO 80225, USA. NR 53 TC 18 Z9 19 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD DEC 20 PY 1995 VL 126 IS 3-4 BP 335 EP 349 DI 10.1016/0009-2541(95)00126-3 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ070 UT WOS:A1995TQ07000009 ER PT J AU Schoell, M Rice, DD AF Schoell, M Rice, DD TI Processes of natural gas formation - Preface SO CHEMICAL GEOLOGY LA English DT Editorial Material C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Schoell, M (reprint author), CHEVRON PETR TECHNOL CO,POB 446,LA HABRA,CA 90633, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD DEC 20 PY 1995 VL 126 IS 3-4 BP R3 EP R3 DI 10.1016/0009-2541(95)90012-8 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ070 UT WOS:A1995TQ07000001 ER PT J AU Langbein, J Wyatt, F Johnson, H Hamann, D Zimmer, P AF Langbein, J Wyatt, F Johnson, H Hamann, D Zimmer, P TI Improved stability of a deeply anchored geodetic monument for deformation monitoring SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID 2-COLOR GEODIMETER MEASUREMENTS; SURFACE MONUMENTS; CALIFORNIA; DISPLACEMENT; PARKFIELD; PRECISION; MOTION AB A test of two different monument designs used in geodetic networks shows that monuments installed to depths of 5 to 10 meters, and laterally braced, exhibit less environmentally caused displacement than those installed to 2 meters depth. At Parkfield, California, we have been monitoring the lengths of 17 baselines over the past decade with a 2 to 3 day interval between measurements using a two-color geodimeter with a nominal precision of 0.5mm over 5km long baselines. Significant variations are observed on many of these baselines which appear to be related to the seasonally occurring rainfall, with the larger variations approaching 10 mm over the past decade. To test whether we could improve upon the measurements on some of the more susceptible lines, at two sites we installed new monuments within about 30 meters of the original monuments. After 1.5 years of measurements it is evident that the new monuments significantly attenuate the seasonal displacements to less than 1 mm. The use of deeply anchored monuments should improve the ability of fault-scale geodetic monitoring arrays to detect small tectonic displacements. C1 UNIV CALIF SAN DIEGO,IGPP 0225,LA JOLLA,CA 92093. RP Langbein, J (reprint author), US GEOL SURVEY,MS 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 14 TC 36 Z9 36 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1995 VL 22 IS 24 BP 3533 EP 3536 DI 10.1029/95GL03325 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TM728 UT WOS:A1995TM72800026 ER PT J AU Stuart, WD Tullis, TE AF Stuart, WD Tullis, TE TI Fault model for preseismic deformation at Parkfield, California SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS-FAULT; STATE DEPENDENT FRICTION; STRIKE-SLIP FAULT; EARTHQUAKE PREDICTION; ROCK FRICTION; CONSTITUTIVE-EQUATIONS; MODERATE EARTHQUAKES; RECURRENCE MODEL; SINGLE DEGREE; SYSTEM AB We construct an earthquake instability model to estimate precursory faulting and ground deformation before the next moderate (M 5.5-6) earthquake on the San Andreas fault near Parkfield, California. The quasi-static model simulates fault slip, fault shear stress, and ground deformation for all stages of repeated earthquake cycles. Unstable slip, which is the analog of a moderate Parkfield mainshock, is caused by overall failure of a postulated strong area or patch of the fault zone, The brittle patch and surrounding weaker viscous fault are defined by the sign of a spatially varying coefficient of a slip rate dependent fault law. Stable failure of the patch leading up to mainshock failure causes slip rate to increase at depth. Amplitudes and timescales of the resulting preseismic deformation anomalies are found for the current earthquake cycle at Parkfield, starting just after the 1966 mainshock, in two ways. In the first way we vary parameter values in a sequence of simulations so as to find the simulation giving best agreement with locations, moments, and recurrence times of past moderate earthquakes and also with fault creep and trilateration line length changes since the 1966 mainshock. In the second way we assign values of most parameters from laboratory friction experiments and a temperature-depth profile inferred from heat flow data. Overall agreement between model results and observations is comparable for the two methods. In all simulations, preseismic deformation anomalies arise from slip rate increase near the model earthquake focus and start several years or less before instability. Preseismic anomalies in surface fault creep and line length are always too small to detect in current measurements. However, for some simulations constrained mainly by field data the predicted anomalies in borehole dilatation are large enough to detect. C1 BROWN UNIV, DEPT GEOL SCI, PROVIDENCE, RI 02912 USA. RP US GEOL SURVEY, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 76 TC 63 Z9 64 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24079 EP 24099 DI 10.1029/95JB02517 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400005 ER PT J AU Stuart, WD Banks, PO Sasai, Y Liu, SW AF Stuart, WD Banks, PO Sasai, Y Liu, SW TI Piezomagnetic field for Parkfield fault model SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CALIFORNIA; EARTHQUAKE; INSTABILITY; FRICTION; STRESSES AB A theoretical piezomagnetic field is calculated as a function of time and ground position for an earthquake instability model applied to moderate (M similar to 6) earthquakes on the San Andreas fault near Parkfield, California. The instability model simulates fault slip and stress for all parts of a 32-year earthquake cycle, including unstable (mainshock) slip. Mainshock slip occurs when a nearly locked patch of the fault becomes suffciently loaded by surrounding aseismic slip that it reaches a condition of rapid failure. The piezomagnetic field is calculated directly from fault slip using analytic solutions based on piezomagnetic nuclei that are analogous to strain nuclei. During the interseismic interval, increasing stress concentration on the locked patch is accompanied by a gradual evolution of the magnetic anomaly field, leading to maximum cumulative changes of about +/-2 nT in the vicinity of the pending epicenter. Mainshock slip cancels about half of the interseismically accumulated changes, and rapid postseismic relaxation cancels most of the rest. At certain sites near the locked patch the rate of change of the field progressively increases during the interseismic interval, while at others it progressively decreases. This effect is most pronounced during the last 3-4 years before the mainshock and, at suitably chosen pairs of sites, results in reversal of the temporal trend of the differential field. Such reversals, if separable from geomagnetic variation due to other sources, would constitute precursory indicators of approaching failure. C1 UNIV TOKYO, EARTHQUAKE RES INST, BUNKYO KU, TOKYO 113, JAPAN. US GEOL SURVEY, MS 977, MENLO PK, CA 94025 USA. RP Stuart, WD (reprint author), CASE WESTERN RESERVE UNIV, DEPT GEOL SCI, CLEVELAND, OH 44106 USA. NR 31 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24101 EP 24110 DI 10.1029/95JB02516 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400006 ER PT J AU Hagstrum, JT Champion, DE AF Hagstrum, JT Champion, DE TI Late Quaternary geomagnetic secular variation from historical and C-14-dated lava flows on Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID PACIFIC NONDIPOLE LOW; PALEOSECULAR VARIATION; PALEOINTENSITY; MAGNETIZATION; COMPACTION; SEDIMENTS; QUESTION AB A paleomagnetic record of geomagnetic paleosecular variation (PSV) is constructed for the last 4400 years based on 191 sites in historical and C-14-dated lava flows from Mauna Loa, Kilauea, and Hualalai Volcanoes on the island of Hawaii. The features of this new record are similar to those recorded by sediments from Lake Waiau near the summit of Mauna Kea Volcano, but overall mean inclinations for the lava flows (31 degrees to 33 degrees, depending on window size) are nearer the expected dipole-field value (35 degrees) than is that for the sediments (27 degrees). Divergence of the inclination records with increasing age suggests that the Lake Waiau values at depths below 2 m have been affected by compaction-related inclination shallowing, although magnetic terrain effects cannot be ruled out. The rate of PSV indicated by the record presented here is highly variable (<0.5 degrees/century to >20 degrees/century), and a pronounced shift in inclination from 25 degrees to 40 degrees occurred between similar to 1030 and similar to 975 years B.P. Paleomagnetic directions from undated materials can be correlated with our calibrated curve, but the resolution is largely dependent on the PSV rate and data densities for both the reference and unknown directions. The upper part of the Puna Basalt (18 lava flows), previously sampled for paleomagnetism along the northern wall of Kilauea's caldera (Uwekahuna Bluff), was likely deposited sometime between 1030 and 750 years B.P., but the lowest two flows beneath the Uwekahuna Ash (similar to 2100 years B.P.) are correlated with an age of similar to 3034 years B.P. Paleomagnetic data for 54 lava flows of the Ka'u Basalt, exposed in the northwest wall of Mauna Loa's summit caldera (Mokuaweoweo), indicate that they probably accumulated over a relatively short time interval (similar to 200+ years) and are assigned to a 1000 to 1199 year B.P. time window. The mean of ages within this window is similar to 1030 years B.P., but mapping and other C-14 dates indicate that these summit overflows are probably closer to similar to 1200 years B.P. in age. RP Hagstrum, JT (reprint author), US GEOL SURVEY, ISOTOPE GEOL BRANCH, MS 937, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 39 TC 22 Z9 22 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24393 EP 24403 DI 10.1029/95JB02913 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400023 ER PT J AU Denlinger, RP Okubo, P AF Denlinger, RP Okubo, P TI Structure of the mobile south flank of Kilauea Volcano, Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MAUNA-LOA AB How do huge landslides occur in Hawaii? We can begin to address this question by examining an incipient landslide structure on the mobile south flank of Kilauea volcano. Between 1970 and 1989 this part of the south flank moved in a southeast direction (seaward by 4 m on its eastern end and by 10 m on its western end), parallel to the western boundary of a large offshore topographic bench. We show that abrupt decreases in cumulative flank movement correspond to abrupt decreases in hypocenter concentration. Most of the earthquakes occur in a 7- to 10-km-deep band beneath the south flank, and relative relocation of a subset of these events shows that they are derived from a single horizontal plane which appears to be a decollement. Focal mechanisms for this deep seismicity are dominated by thrust fault mechanisms. with the overlying block moving seaward. A comparison of south flank bathymetry with decollement structures on other volcanoes suggests that the distal end of this decollement coincides with the distal end of the offshore topographic bench (30-50 km from shore and 5 km below sea level). The fault system forming the Hilina pall is connected with this decollement, so that slip on the Hilina pall's normal faults coincides with slip of the decollement and with reverse faulting of the distal end of the bench. (This interpretation is supported by studies of the events associated with the M 7.2 Kalapana earthquake in 1975.) When the Hilina pall is connected to the outer bench with a decollement inferred from seismicity, a wedge 8-km thick adjacent to Kilauea's magma system and 1-2 km thick along the edge of the outer bench (an area over 3000 km(2)) is defined. The thickness adjacent to the magma system decreases eastward along Kilauea's East Rift Zone and southwestward from Kilauea caldera, whereas the thickness of the lip of the outer bench decreases only eastward. Geologic observations and geophysical studies of the subaerial flank reveal an extensive magma system beneath the Koae fault system as well as beneath Kilauea caldera and its East Rift Zone. We infer that the boundary of the proximal end of the mobile flank is the southern boundary of this magma system and that this boundary coincides with the southern boundaries of both the Koae fault system and Kilauea's East Rift Zone. RP Denlinger, RP (reprint author), US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, POB 51, HAWAII VOLCANOES NATL PK, HILO, HI 96718 USA. NR 41 TC 66 Z9 66 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24499 EP 24507 DI 10.1029/95JB01479 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400029 ER PT J AU Moore, JG Hickson, CJ Calk, LC AF Moore, JG Hickson, CJ Calk, LC TI Tholeiitic-alkalic transition at subglacial volcanoes, Tuya region, British Columbia, Canada SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ICELAND; BASALT AB Ash Mountain, South Tuya, and Tuya Butte are three small basaltic volcanoes in the Stikine volcanic belt of northern British Columbia. The volcanoes rise 700, 500, and 400 m above their bases and are about 3.2, 1.6, and 2.6 km(3) in volume, respectively. They began eruptive activity under several hundred meters of overlying glacial ice, or water in an ice-impounded lake, and undegassed pillow lava was erupted and forms the bases of all three. Later, as the vents grew into shallow water, explosive phreatomagmatic activity erupted partly degassed glassy tuffs. Finally, when the volcano emerged through the surface of the ice or water (or the water was drained), degassed subaerial lava flows were erupted and were converted to assemblages of foreset-bedded pillow breccia and pillow lava when subaerial flows crossed a shoreline and flowed into meltwater lakes. The undegassed subglacial pillow base of Ash Mountain is overlain by partly degassed pillows and hyaloclastite tuff cut by dikes; at South Tuya the pillow base is overlain by hyaloclastite tuffs and lenses of pillow lava; at Tuya Butte the pillow base is overlain by foreset-bedded pillow lava, pillow breccias, and hyaloclastite tuffs, which in turn are overlain by subaerial lava flows composing a small shield volcano. The undegassed basal subglacial pillow lava of the three volcanoes contain 0.10 +/- 0.01 wt % sulfur and similar to 0.5 wt % H2O. The overlying partly degassed assemblages contain 0.06 +/- 0.02% sulfur and similar to 0.2% H2O at Ash Mountain, 0.07 +/- 0.01% sulfur at South Tuya, and 0.03 +/- 0.01% sulfur at Tuya Butte. The differences in the degree of degassing can be related to the nature of eruption and quenching and the distance of flow of the subaerial lava. When the volcanoes switched from subglacial to shallow water or subaerial eruptions, as shown by change to more explosive activity and then to subaerial lava flows (and by a marked reduction of sulfur in volcanic glass), the magma shifted from tholeiitic to alkalic composition. This transition occurs at each of the three volcanoes. The tholeiitic and alkalic magmas cannot be related by shallow crystal fractionation and apparently originated by differing degrees of deep melting at a mantle source. Prior to eruption the tholeiitic melts overlay alkalic melts in shallow chambers underlying each of the volcanoes because of their lower density and were, therefore, the first to erupt under subglacial conditions. As the volcano grew through the ice (or ice-impounded water), the volcanic conduit vented to the atmosphere, producing a partial depressurization of the conduit and the subsurface chamber. This sudden reduction in confining pressure caused enhanced vesiculation of volatile saturated melts, particularly of the more volatile-rich alkalic melts, causing them to rise to the top of the chamber and erupt. C1 GEOL SURVEY CANADA, VANCOUVER, BC V6B 1R8, CANADA. RP Moore, JG (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 910, MENLO PK, CA 94025 USA. NR 31 TC 20 Z9 20 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24577 EP 24592 DI 10.1029/95JB02509 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400034 ER PT J AU Best, MG Christiansen, EH Deino, AL Gromme, CS Tingey, DG AF Best, MG Christiansen, EH Deino, AL Gromme, CS Tingey, DG TI Correlation and emplacement of a large, zoned, discontinuously exposed ash flow sheet: The Ar-40/Ar-39 chronology, paleomagnetism, and petrology of the Pahranagat Formation, Nevada SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DISCRIMINATION; CALIBRATION; TUFFS; KENYA; ROCKS; UTAH AB Many single-crystal Ar-40/Ar-39 ages and thermoremanent magnetization directions have resolved the problematic stratigraphic correlation of the laterally and vertically zoned rhyolite ash flow sheet of the Pahranagat Formation in the southern Great Basin. This outflow sheet was previously designated by four different stratigraphic names in different locations over its highly discontinuous exposure area of 33,000 km(2). We show that it is a single cooling unit emplaced at 22.639 +/- 0.009 Ma around its source, the Kawich caldera. The volume of the outflow sheet was about 1600 km(3) after compensation for 50% post volcanic east-west extension. A comparable volume of tuff likely accumulated inside the Kawich caldera. Modal and chemical compositions of bulk tuff and cognate pumice fragments, together with compositions of phenocrysts, show the preeruption magma body was zoned from high-silica rhyolite (two feldspars, quartz, biotite, and titanomagnetite) to underlying, silica-poor, more mafic rhyolite and trachydacite (plagioclase, minor biotite, titanomagnetite, amphibole, and clinopyroxene). Initial evacuation of the uppermost evolved zone produced proximal outflow hundreds of meters thick of relatively densely welded, pumice-poor, high-silica rhyolite tuff. As eruption progressed, tens of meters of more mafic ejecta were deposited in distal areas and locally near the caldera and consist of less welded, pumice-rich ash flow tuff derived by physical mixing of pyroclasts from all zones of the magma chamber. This mixing during eruption invalidates direct comparison of the composition of tuff and a particular part of the magma chamber. The Pahranagat ash flow sheet provides a rigorous test case for application of high-precision correlation tools because of the zonal emplacement of ejecta from the compositionally stratified magma chamber together with the subsequent tectonic dismemberment and erosion of the sheet that created widely scattered exposures. C1 BERKELEY GEOCHRONOL CTR, BERKELEY, CA 94709 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP BRIGHAM YOUNG UNIV, DEPT GEOL, PROVO, UT 84602 USA. RI Christiansen, Eric/A-8948-2009 NR 33 TC 28 Z9 28 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24593 EP 24609 DI 10.1029/95JB01690 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400035 ER PT J AU Zierenberg, RA Schiffman, P Jonasson, IR Tosdal, R Pickthorn, W McClain, J AF Zierenberg, RA Schiffman, P Jonasson, IR Tosdal, R Pickthorn, W McClain, J TI Alteration of basalt hyaloclastite at the off-axis Sea Cliff hydrothermal field, Gorda Ridge SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Workshop on the Mantle-Ocean Connection CY AUG 24-26, 1994 CL AMSTERDAM, NETHERLANDS SP European Assoc Geochem, Netherlands Res Sch Sedimentary Geol ID EAST PACIFIC RISE; MASSIVE SULFIDE DEPOSITS; ISOTOPIC COMPOSITION; ELECTRON-MICROPROBE; HEAVY-METALS; 500 BARS; 21-DEGREES-N; SEAWATER; SULFUR; OCEAN AB The Sea Cliff hydrothermal field on the northern segment of the Gorda Ridge is situated along a rift-bounding normal fault about 2.6 km east of the neovolcanic zone and approximately 300 m above the spreading axis, The structural setting of this hydrothermal field differs from that of most other active seafloor hydrothermal sites investigated to date, which are typically situated in the neovolcanic zone, Mineralization occurs in basaltic talus covering a large normal-fault scarp, Hydrothermal crusts cover much of the seafloor in the area of the active hydrothermal field. These crusts form by extensive alteration of basaltic hyaloclastite in a zone of mixing between ascending hydrothermal fluid and entrained seawater. The initial stage of alteration is magnesian metasomatism of both crystalline basalt and basaltic glass, converting the rock to Mg-rich smectite and smectite/ chlorite, Further alteration removes nearly all cations and ultimately leads to silicification. Preservation of basaltic texture in the silicified rocks provides evidence that even such sparingly soluble elements as Al and Ti have been removed, Oxygen-isotopic ratios of the altered rocks constrain initial alteration to temperatures near 220 degrees C, close to the maximum measured vent temperatures of 247 degrees C, Silicification proceeded to much lower temperatures, and most amorphous silica deposition occurred at temperatures below 100 degrees C. Sulfur-, strontium-, and lead-isotopic data all indicate a predominantly basaltic source, with important contributions from seawater but no significant contribution from sedimentary sources. Comparison with ophiolite-hosted massive sulfide deposits shows that the structural setting, alteration sequence, and depositional environment are all similar and suggests that mineralization and replacement of basaltic breccia in the Sea Cliff hydrothermal field likely occur in the subsurface beneath a capping layer of silicified hyaloclastite. C1 UNIV CALIF DAVIS,DEPT GEOL,DAVIS,CA 95616. GEOL SURVEY CANADA,OTTAWA,ON K1A 0E8,CANADA. RP Zierenberg, RA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 901,MENLO PK,CA 94025, USA. RI Zierenberg, Robert/F-9329-2012 OI Zierenberg, Robert/0000-0001-9384-7355 NR 58 TC 27 Z9 27 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD DEC 5 PY 1995 VL 126 IS 2 BP 77 EP 99 DI 10.1016/0009-2541(95)00111-2 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK833 UT WOS:A1995TK83300002 ER PT J AU MAGOON, LB SANCHEZ, RMO AF MAGOON, LB SANCHEZ, RMO TI BEYOND THE PETROLEUM SYSTEM SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID CLASSIFICATION; BASIN; PLAYS; OIL AB The first joint AAPG/AMGP (Association of Mexican Petroleum Geologists) Hedberg Conference on ''Geologic Aspects of Petroleum Systems'' was held October 2-6, 1994, in Mexico City, Mexico. This research conference attracted nearly 150 geoscientists from 15 countries; 41 papers and 27 posters were presented. The opposite response occurred when the petroleum-system concept was presented more than 20 yr ago; it was largely overlooked. In the past decade, however interest in this concept as an exploration tool has been growing rapidly. The research conference addressed the concept itself, its elements and processes, the tools and methods used to identify a petroleum system, and many case studies. We summarize responses by the participants to the following three questions. First, what is gained from using the petroleum-system concept? Second, in what new directions will the petroleum-system concept take us in the future? Third, has anything new come out of this research conference? C1 PETR MEXICANOS,PROLONGAC AMORES,MEXICO CITY 03100,DF,MEXICO. RP MAGOON, LB (reprint author), US GEOL SURVEY,MS 999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 34 TC 4 Z9 10 U1 1 U2 2 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD DEC PY 1995 VL 79 IS 12 BP 1731 EP 1736 PG 6 WC Geosciences, Multidisciplinary SC Geology GA TJ285 UT WOS:A1995TJ28500002 ER PT J AU Yen, S Liu, SP Kolpin, D AF Yen, S Liu, SP Kolpin, D TI Analysis of nitrate in near-surface aquifers in the midcontinental United States: An application of the inverse hyperbolic sine tobit models SO AMERICAN JOURNAL OF AGRICULTURAL ECONOMICS LA English DT Meeting Abstract C1 IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. US GEOL SURVEY,IOWA CITY,IA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER AGRICULTURAL ECONOMICS ASSOC PI AMES PA 1110 BUCKEYE AVE, AMES, IA 50010-8063 SN 0002-9092 J9 AM J AGR ECON JI Am. J. Agr. Econ. PD DEC PY 1995 VL 77 IS 5 BP 1358 EP 1358 PG 1 WC Agricultural Economics & Policy; Economics SC Agriculture; Business & Economics GA UA027 UT WOS:A1995UA02700083 ER PT J AU Laughland, A Shortle, J Musser, W AF Laughland, A Shortle, J Musser, W TI Nonpoint source pollution regulation in a second best world SO AMERICAN JOURNAL OF AGRICULTURAL ECONOMICS LA English DT Meeting Abstract C1 US FISH & WILDLIFE SERV,WASHINGTON,DC. PENN STATE UNIV,UNIVERSITY PK,PA 16802. UNIV MARYLAND,COLLEGE PK,MD 20742. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER AGRICULTURAL ECONOMICS ASSOC PI AMES PA 1110 BUCKEYE AVE, AMES, IA 50010-8063 SN 0002-9092 J9 AM J AGR ECON JI Am. J. Agr. Econ. PD DEC PY 1995 VL 77 IS 5 BP 1388 EP 1388 PG 1 WC Agricultural Economics & Policy; Economics SC Agriculture; Business & Economics GA UA027 UT WOS:A1995UA02700357 ER PT J AU Shealy, DB Lohrmann, R Ruth, JR Narayanan, N Sutter, SL Casay, GA Evans, L Patonay, G AF Shealy, DB Lohrmann, R Ruth, JR Narayanan, N Sutter, SL Casay, GA Evans, L Patonay, G TI Spectral characterization and evaluation of modified near-infrared laser dyes for DNA sequencing SO APPLIED SPECTROSCOPY LA English DT Article DE near-infrared; DNA sequencing; fluorescence; cyanine dyes; oligonucleotides ID GAUCHERS-DISEASE; ELECTROPHORESIS; PRIMERS AB Several derivatives of IR-144, a commercially available near-infrared (near-IR) laser dye, have been synthesized with different moieties, which produce bathochromic shifts of the absorbance maximum without affecting their fluorescence emission spectrum. With this capability, the absorbance maximum of the dye can be adjusted to coincide with the maximum output wavelength of various semiconductor laser diodes. This capability allows compatibility with a multidye fluorescence system that has different excitation sources but a common near-IR detector, The utility of IR-144 derivatives with an absorbance maximum close to the output wavelength of commercially available semiconductor laser diodes was illustrated by coupling oligonucleotide primers that contain an amino linker to a dye derivative and sequencing DNA with the use of an instrument designed specifically for near-IR detection. Before sequencing reactions were performed, the near-IR laser dye-DNA conjugates were purified by reversed-phase high-performance liquid chromatography. We report the synthesis and spectral characterization of IR-144 derivatives. In addition, the conjugation reaction between the near-IR laser dye and amino-modified oligonucleotides and subsequent purification is discussed. Data that validate the subfemptomole detection of the labeled DNA strands are presented. C1 GEORGIA STATE UNIV,DEPT CHEM,ATLANTA,GA 30303. MOLEC BIOSYST INC,SAN DIEGO,CA 92121. US FISH & WILDLIFE SERV,FORENS LAB,ASHLAND,OR 97520. LI COR INC,LINCOLN,NE 68504. RI Barr, Dana/E-6369-2011; Barr, Dana/E-2276-2013 NR 30 TC 9 Z9 13 U1 0 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD DEC PY 1995 VL 49 IS 12 BP 1815 EP 1820 DI 10.1366/0003702953965858 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA TM586 UT WOS:A1995TM58600019 ER PT J AU Kerby, JH Everson, JM Harrell, RM Starling, CC Revels, H Geiger, JG AF Kerby, JH Everson, JM Harrell, RM Starling, CC Revels, H Geiger, JG TI Growth and survival comparisons between diploid and triploid sunshine bass SO AQUACULTURE LA English DT Meeting Abstract C1 NATL BIOL SURVEY,LEETOWN SCI CTR,AQUAT ECOL LAB,KEARNEYSVILLE,WV 25430. UNIV MARYLAND,HORN POINT ENVIRONM LAB,CAMBRIDGE,MD 21613. FLORIDA GAME & FRESH WATER FISH COMMISS,WEBSTER,FL 33597. US FISH & WILDLIFE SERV,HADLEY,MA 01035. NR 0 TC 4 Z9 5 U1 3 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD DEC 1 PY 1995 VL 137 IS 1-4 BP 355 EP 355 DI 10.1016/0044-8486(96)83592-7 PG 1 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA TN873 UT WOS:A1995TN87300105 ER PT J AU Coates, JD Lonergan, DJ Philips, EJP Jenter, H Lovley, DR AF Coates, JD Lonergan, DJ Philips, EJP Jenter, H Lovley, DR TI Desulfuromonas palmitatis sp nov, a marine dissimilatory Fe[III] reducer that can oxidize long-chain fatty acids SO ARCHIVES OF MICROBIOLOGY LA English DT Article DE Desulfuromonas; Fe(III) reduction; sulfur reduction; marine sediments; palmitate ID ORGANIC-CARBON OXIDATION; FERRIC IRON; PHYLOGENETIC ANALYSIS; MANGANESE REDUCTION; SULFATE REDUCTION; RIBOSOMAL-RNA; GEN-NOV; SEDIMENTS; MICROORGANISM; BACTERIA AB Studies on the microorganisms living in hydrocarbon-contaminated sediments in San Diego Bay, California led to the isolation of a novel Fe(III)-reducing microorganism. This organism, designated strain SDBY1, was an obligately anaerobic, non-motile, non-flagellated, gram-negative rod. Strain SDBY1 conserves energy to support growth from the oxidation of acetate, lactate, succinate, fumarate, laurate, palmitate, or stearate. Hz was also oxidized with the reduction of Fe(III), but growth with H-2 as the sole electron donor was not observed. In addition to various forms of soluble and insoluble Fe(III), strain SDBY1 also coupled growth to the reduction of fumarate, Mn(IV), or S-o. Air-oxidized minus dithionite-reduced difference spectra exhibited peaks at 552.8, 523.6, and 422.8 nm, indicative of c-type cytochrome(s). Strain SDBY1 shares physiological characteristics with organisms in the genera Geobacter, Pelobacter, and Desulfuromonas. Detailed analysis of the 16S rRNA sequence indicated that strain SDBY1 should be placed in the genus Desulfuromonas. The new species name Desulfuromonas palmitatis is proposed. D. palmitatis is only the second marine organism found (after D. acetoxidants) to oxidize multicarbon organic compounds completely to carbon dioxide with Fe(III) as an electron acceptor and provides the first pure culture model for the oxidation of long-chain fatty acids coupled to Fe(III) reduction. C1 UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003. US GEOL SURVEY,DIV WATER RESOURCES,NATL CTR 430,RESTON,VA 22092. NR 50 TC 103 Z9 110 U1 5 U2 15 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0302-8933 J9 ARCH MICROBIOL JI Arch. Microbiol. PD DEC PY 1995 VL 164 IS 6 BP 406 EP 413 PG 8 WC Microbiology SC Microbiology GA TM487 UT WOS:A1995TM48700004 PM 8588742 ER PT J AU Reimnitz, E Eicken, H Martin, T AF Reimnitz, E Eicken, H Martin, T TI Multiyear fast ice along the Taymyr Peninsula, Siberia SO ARCTIC LA English DT Article DE multiyear land-fast sea ice; incipient ice shelves; sediment entrainment; interglacial glacial transition; Siberia; Laptev Sea ID FAST SEA-ICE; SEDIMENT; GROWTH; ALASKA AB A 20 km wide zone of fast ice, reaching offshore to the 20 m isobath and sealing off coastal embayments along the Taymyr Peninsula, survived until at least 23 November 1993, becoming multiyear land-fast sea ice (MLSI). Barrier islands show characteristic recurved spits indicating dominant southwest direction of longshore transport in intermittent years. At the time of observation, the fast ice was undisturbed, only heaving vertically with tides, protecting the coastal zone from wave reworking. The 1 to 2 m thick ice cover affects light and oxygen, creating profound effects on marine life in the zone. A herd of walrus, in other summers reported to haul out on local beaches, was displaced by the fast ice. We saw no evidence for sediment loading of the ice by rivers or for eolian deposition on ice. MLSI is considered an incipient ice shelf, which could grow in thickness and strength in successive winters. Salinity and delta(18)O profiles in ice cores from some smaller areas of MLSI provide a record of environmental conditions during the first year of ice growth, such as local hydrography and contribution of congealed snow to the solid fast ice. On ice charts we found no record of waxing and waning MLSI in the area, and do not know whether the observed ice survived the next summer. Since arctic ice shelves have developed from MLSI in the past, the observed phenomenon permits a view of how transitions from interglacial to full glacial conditions can begin. C1 ALFRED WEGENER INST POLAR & MARINE RES,D-27515 BREMERHAVEN,GERMANY. RP Reimnitz, E (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 999,MENLO PK,CA 94025, USA. RI Eicken, Hajo/M-6901-2016 NR 29 TC 9 Z9 9 U1 0 U2 1 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY AB T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD DEC PY 1995 VL 48 IS 4 BP 359 EP 367 PG 9 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA TP285 UT WOS:A1995TP28500008 ER PT J AU Hough, SE Dreger, DS AF Hough, SE Dreger, DS TI Source parameters of the 23 April 1992 M 6.1 Joshua Tree, California, earthquake and its aftershocks: Empirical green's function analysis of GEOS and TERRAscope data SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID NORTH PALM-SPRINGS; CORNER FREQUENCIES; SITE RESPONSE; FAULT PLANE; SPECTRA; MODELS; INVERSION; EVENTS; WAVES AB Source parameters of-the M 6.1 23 April 1992 Joshua Tree mainshock and 86 M 1.8 to 4.9 aftershocks are determined using an empirical Green's function methodology. For the aftershocks, deconvolved P- and S-wave spectra are calculated for 126 pairs of closely spaced events recorded on portable GEOS stations; S-wave spectra from the two horizontal components are averaged. The deconvolved spectra are fit by a ratio of omega-square source models, yielding an optimal (least-squares) corner frequency for both the large and the small event in each pair. We find no resolved difference between the inferred P- and S-wave corner frequencies. Using the standard Brune model for stress drop, we also find no resolved nonconstant scaling of stress drop with moment, although we also conclude that detailed scaling systematics would be difficult to resolve. In particular, a weak increase of stress drop with moment over a limited moment/magnitude cannot be ruled out. For magnitudes smaller than M 3 to 3.5, the inferred stress-drop values will be limited by the maximum observable corner frequency value of 60 Hz. For the mainshock, source-time functions are obtained from mainshock recordings at three TERRAscope stations (PFO, PAS, and GSC) using an M 4.3 foreshock as an empirical Green's function. The results indicate a fairly simple, single-pulse source-time function, with clear south-to-north directivity and an inferred rupture radius of 5 to 6 km. The deconvolved source-time functions are inverted to obtain a finite-rupture model that gives a robust estimate of rupture dimension. Early aftershocks are found to lie along the perimeters of regions with high mainshock slip. The inferred mainshock stress-drop value, 56 bars, is within the range determined for the aftershocks. Our derived mainshock source spectra do not show resolvable deviation from the omega-square model. C1 UNIV CALIF BERKELEY,SEISMOG STN,BERKELEY,CA 94720. RP Hough, SE (reprint author), US GEOL SURVEY,PASADENA,CA 91106, USA. NR 44 TC 63 Z9 66 U1 0 U2 5 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD DEC PY 1995 VL 85 IS 6 BP 1576 EP 1590 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TL814 UT WOS:A1995TL81400004 ER PT J AU Frohlich, C KadinskyCade, K Davis, SD AF Frohlich, C KadinskyCade, K Davis, SD TI A reexamination of the Bucaramanga, Colombia, earthquake nest SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID MOMENT TENSOR SOLUTIONS; FOCAL MECHANISMS; MAGNITUDE SCALE; B-VALUES; SEISMICITY; PLATE AB The Bucaramanga earthquake nest is situated at a depth of about 160 km beneath Colombia at 6.8 degrees N, 73 degrees W, and it produces about eight earthquakes of m(b) 4.7 or more each year from a source region having dimensions of about 10 km or less. In this study, we evaluate nest properties using reported locations, focal mechanisms, and moment tensors, as well as relocations determined from teleseismic P, pP, and PKP arrivals. We also introduce a novel method for determining the ''volume'' of a group of hypocenters and use this volume as a statistic for evaluating the accuracy of nest hypocenters. We have relocated 26 nest earthquakes occurring between 1964 and 1986 using the JHD method and carefully reread teleseismic P, pP, and PKPdf arrivals. The relocated earthquakes cluster within a region having a volume of 776 km(3) and east-west, north-south, and vertical dimensions of 13 x 18 X 12 km, a smaller region than any found previously from analysis of teleseismic data. In practical terms, this represents an approximate upper bound on the accuracy of relative earthquake locations possible using teleseismic data and standard relocation methods. This compares with a volume of 11 km(3) and dimensions of 5.1 x 3.4 X 3.8 km as determined by Schneider et al. (1987) from observations of microearthquakes collected over 16 days with a temporary local network. These dimensions are comparable to those of the rupture dimensions of the largest observed nest earthquakes, as determined from an analysis of their seismic moments (similar to 5 X 10(24) dyne-cm). Furthermore, an evaluation of cumulative moment rate since 1964 indicates that strain rates within the nest volume must be between 10(-13)/sec and 10(-11)/sec. The b values (similar to 2.0) and beta values (similar to 0.9) determined from available magnitudes and moments are remarkably high, suggesting that earthquakes of all observed sizes (3 X 10(20) to 5 X 10(24) dyne-cm) contribute significantly to the moment release. Focal mechanisms determined from teleseismic observations exhibit a consistent pattern, most having westward-dipping P axes and eastward-dipping T axes; this differs from the more varied pattern reported by Schneider et al. (1987) for microseismic earthquakes. C1 PHILLIPS LAB, GEOPHYS DIRECTORATE, DIV EARTH SCI, BEDFORD, MA 01731 USA. MEMPHIS UNIV, CERI, US GEOL SURVEY, MEMPHIS, TN 38152 USA. RP UNIV TEXAS, INST GEOPHYS, AUSTIN, TX 78759 USA. RI Frohlich, Cliff/A-8573-2008 NR 36 TC 14 Z9 14 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD DEC PY 1995 VL 85 IS 6 BP 1622 EP 1634 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TL814 UT WOS:A1995TL81400007 ER PT J AU Harp, EL Wilson, RC AF Harp, EL Wilson, RC TI Shaking intensity thresholds for rock falls and slides: Evidence from 1987 Whittier Narrows and Superstition Hills earthquake strong-motion records SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID RUPTURE PROCESS; CALIFORNIA; INVERSION AB Due to inconsistencies in using descriptive intensity scales to describe earthquake shaking necessary to trigger landslides, Arias intensity, a quantity calculated from seismic strong-motion records, has been employed as a measure of the seismic energy required to initiate landslides. Because Arias intensity is defined as the sum of all the squared acceleration values from a strong-motion record, it is a measure of the energy dissipated at a site by shaking. It incorporates both amplitude and duration information, making it more useful to compare with the failure of slopes than parameters, such as peak acceleration. Arias intensities calculated from the 24 October 1987 Superstition Hills and the I October 1987 Whittler Narrows earthquakes in southern California allow comparisons with the limits of landslides, specifically, falls and slides from rock and soil in these two earthquakes. These comparisons establish two shaking thresholds for the Limits of falls and slides. A range of 0.08 to 0.6 m/sec is observed for Tertiary and younger deposits, while the range of 0.01 to 0.07 m/sec is observed for Mesozoic and older rocks. These two ranges of shaking levels are controlled by the relative degree of fracturing and aperture of fracture systems within the two general age groups of rocks and soils in the Los Angeles area and the Imperial Valley. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Harp, EL (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 966,DENVER,CO 80225, USA. NR 26 TC 64 Z9 73 U1 0 U2 3 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD DEC PY 1995 VL 85 IS 6 BP 1739 EP 1757 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TL814 UT WOS:A1995TL81400016 ER PT J AU Davis, SD Nyffenegger, PA Frohlich, C AF Davis, SD Nyffenegger, PA Frohlich, C TI The 9 April 1993 earthquake in south-central Texas: Was it induced by fluid withdrawal? SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID GAS-FIELD; SEISMICITY; CALIFORNIA; STRESS; OIL AB An earthquake that occurred 9 April 1993, about 80-km south of San Antonio, is the largest earthquake known (m(b)Lg = 4.3) in south-central Texas in historic times. The earthquake was felt over a 4000-km(2) area, and modified Mercalli intensities were as high as VI at a gas production facility near Fashing, Texas. Similar, smaller events have occurred since 1973 at three sites near Fashing, Pleasanton, and Falls City, Texas. We propose a list of nine yes-no questions to assess whether a sequence of earthquakes may have been induced by fluid withdrawal. The criteria suggest that at least two sites (Fashing and Pleasanton) had earthquakes that were induced by fluid withdrawal related to ongoing oil and gas production. An alternative possibility is that these events are the southwesternmost examples in a band of weak, natural seismic activity between 135 and 240 km from the coast of the Gulf of Mexico and extending from this region east to the Texas-Louisiana border. In addition, some injection occurs at all three sites, although the volumes of fluid injected at Fashing and Pleasanton are low enough as to make injection an unlikely cause. C1 MEMPHIS UNIV, CTR EARTHQUAKE RES & INFORMAT, MEMPHIS, TN 38152 USA. UNIV TEXAS, DEPT GEOL SCI, AUSTIN, TX 78759 USA. UNIV TEXAS, INST GEOPHYS, AUSTIN, TX 78759 USA. RP MEMPHIS UNIV, US GEOL SURVEY, MEMPHIS, TN 38152 USA. RI Frohlich, Cliff/A-8573-2008 NR 29 TC 22 Z9 23 U1 2 U2 7 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD DEC PY 1995 VL 85 IS 6 BP 1888 EP 1895 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TL814 UT WOS:A1995TL81400028 ER PT J AU Parfitt, EA Wilson, L Neal, CA AF Parfitt, EA Wilson, L Neal, CA TI Factors influencing the height of Hawaiian lava fountains: Implications for the use of fountain height as an indicator of magma gas content SO BULLETIN OF VOLCANOLOGY LA English DT Article DE lava fountains; magma gas content; volume flux; re-entrainment; gas bubble coalescence; lava re-entrainment; Pu'u 'O'o eruption ID KILAUEA VOLCANO; EAST RIFT; PUU-OO; ERUPTIONS; GEOMETRY; PRESSURE; PATTERNS; DYNAMICS; SYSTEMS; STORAGE AB The heights of lava fountains formed in Hawaiian-style eruptions are controlled by magma gas content, volume flux and the amounts of lava re-entrainment and gas bubble coalescence. Theoretical models of lava fountaining are used to analyse data on lava fountain height variations collected during the 1983-1986 Pu 'u 'O'o vent of Kilauea volcano, Hawaii. The results show that the variable fountain heights can be largely explained by the impact of variations in volume flux and amount of lava re-entrainment on erupting magmas with a constant gas content of similar to 0.32 wt.% H2O. However, the gas content of the magma apparently declined by similar to 0.05 wt.% during the last 10 episodes of the eruption series and this decline is attributed to more extensive pre-eruption degassing due to a shallowing of the sub-vent feeder dike. It is concluded that variations in lava fountain height cannot be simply interpreted as variations in gas content, as has previously been suggested, but that fountain height can still be a useful guide to minimum gas contents. Where sufficient data are available on eruptive volume fluxes and extent of lava entrainment, greatly improved estimates can be made of magma gas content from lava fountain height. C1 BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. UNIV LANCASTER,DIV ENVIRONM SCI,LANCASTER LA1 4YQ,ENGLAND. US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. NR 31 TC 39 Z9 39 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD DEC PY 1995 VL 57 IS 6 BP 440 EP 450 DI 10.1007/s004450050104 PG 11 WC Geosciences, Multidisciplinary SC Geology GA TN584 UT WOS:A1995TN58400005 ER PT J AU Cain, DJ Luoma, SN Axtmann, EV AF Cain, DJ Luoma, SN Axtmann, EV TI Influence of gut content in immature aquatic insects on assessments of environmental metal contamination SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID DECOMPOSING PLANKTONIC DEBRIS; CONSPERSA CURTIS TRICHOPTERA; TRACE-METALS; BENTHIC INVERTEBRATES; RELEASE RATES; HEAVY-METALS; ELEMENTS; SEDIMENT; CADMIUM; LARVAE AB We evaluated the effect of metal associated with the gut content in immature aquatic insects (larvae and nymphs) on spatial and interspecific comparisons of whole-body metal concentrations. Four species, common to cobble-bottom rivers and streams, were collected along an established contamination gradient in the Clark Fork River, and from tributaries of the Clark Fork. Metal concentrations were determined in the gut and its content and in the insect body. Whole-body metal concentrations were higher and more variable as a result of gut content. The positive bias produced by the gut content did not alter interpretations of site contamination in most cases. Interspecific comparisons of metal bioaccumulation also were not greatly affected by the presence of gut content. The influence of gut content was specific for metal, species, and site. Feeding habit, gut size, and metal bioaccumulation in the body affected the relative contribution of the gut and its content to metal concentrations in the whole insect. C1 US GEOL SURVEY,BOULDER,CO 80303. RP Cain, DJ (reprint author), US GEOL SURVEY,MS 465,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. OI Cain, Daniel/0000-0002-3443-0493 NR 40 TC 25 Z9 27 U1 0 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 1995 VL 52 IS 12 BP 2736 EP 2746 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UA096 UT WOS:A1995UA09600020 ER PT J AU Sherlock, RL Tosdal, RM Lehrman, NJ Graney, JR Losh, S Jowett, EC Kesler, SE AF Sherlock, RL Tosdal, RM Lehrman, NJ Graney, JR Losh, S Jowett, EC Kesler, SE TI Origin of the McLaughlin mine sheeted vein complex: Metal zoning, fluid inclusion, and isotopic evidence SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Review ID WAIOTAPU GEOTHERMAL SYSTEM; GREAT VALLEY SEQUENCE; THERMAL WATERS; CLAY-MINERALS; ORE-DEPOSITS; NEW-ZEALAND; ARC BASIN; CALIFORNIA; OXYGEN; NORTHERN AB The McLaughlin deposit is a large hot spring-type gold deposit located in the northern Coast Ranges of California at the faulted lithologic contact between the Coast Range ophiolite and the Great Valley sequence. The McLaughlin deposit is centered around the sheeted vein complex, a large multistage vein swarm, localized in a dilation zone formed by theologic contrasts in the footwall polymictic melange. The surface expression of tile sheeted vein complex is a subaerial sinter terrace. Metal zoning in the sheeted vein complex is highly telescoped. The sinter is enriched in mercury, whereas gold and silver are restricted to the upper 350 m, with the proportion of gold to silver decreasing with depth. Gold is typically present as electrum and is associated with silver and base metal-bearing sulfosalts. Below 350 m mineralization is dominated by small quartz veins with base metal sulfides. Fluid inclusion studies indicate that NaCl is the main dissolved salt, in concentrations averaging 2.4 wt percent NaCl equiv. The bulk of the salinity data can be explained by variable amounts of adiabatic boiling and mixing with steam-heated ground water. Fluid inclusion homogenization data ranges from 121 degrees to 263 degrees C with the deepest portion of the system examined having the highest temperatures and the shallowest samples having the lowest temperatures. Fluid inclusion gas concentrations vary with depth below the sinter; CO2, and to a lesser extent CH4, shows a systematic increase with depth. Fluid pressures, calculated from fluid inclusion homogenization temperatures and gas analysis, are in excess of the hydrostatic pressure and approach, or exceed, lithostatic pressure. Self-sealing of the system and tectonic dilation most likely resulted in catastrophic phase separation and hydrothermal eruption breccias. Geothermometry results, based on fluid inclusion gas ratios, show a reasonable correspondence with the highest fluid inclusion homogenization temperatures. There is a strong trend for decreasing delta(18)O(quartz) values with depth due to the effect of temperature. The calculated delta(18)O(H2O) values are fairly constant at about 9 to 10 per mil. Oxygen and hydrogen isotope values, as well as geologic relationships, are consistent with those of hydrothermal fluids originating as meteoric water; these evolved to increasingly high ones by interaction with Great Valley sequence sedimentary rocks. Lead isotope compositions, of sulfides and potential source rocks, indicate that lead, and by inference other metals, was derived from a crustal source. The lead source may have been detritus from the Sierra Nevada batholith that comprises the Great Valley sequence, or alternatively, it may have been derived from a thorough mixture of radiogenic lead and nonradiogenic lead that occurred prior to mineralization. C1 UNIV WATERLOO,DEPT EARTH SCI,WATERLOO,ON N2L 3G1,CANADA. UNIV WATERLOO,WATERLOO CTR GROUND WATER RES,WATERLOO,ON N2L 3G1,CANADA. US GEOL SURVEY,MENLO PK,CA 94025. HOMESTAKE MIN CO INC,SPARKS,NV 89431. UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. CORNELL UNIV,DEPT GEOL SCI,ITHACA,NY 14853. NR 108 TC 39 Z9 41 U1 0 U2 1 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1995 VL 90 IS 8 BP 2156 EP 2181 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF903 UT WOS:A1995UF90300003 ER PT J AU LeAnderson, PJ Yoldash, M Johnson, PR Offield, TW AF LeAnderson, PJ Yoldash, M Johnson, PR Offield, TW TI Structure, vein paragenesis, and alteration in the Al Wajh gold district, Saudi Arabia SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID OPHIOLITES; ACCRETION; SHIELD AB The Al Wajh gold district contains small deposits of gold-bearing quartz veins located in sheared and altered Neoproterozoic mafic lavas and volcaniclastic sandstone and siltstone. Tile veins formed during multiple episodes of deformation and have structural and mineralogic features characteristic of mesothermal, low sulfide, gold-bearing quartz veins. Three early deformation episodes (D-1, D-2, D-3) are interpreted as progressive phases of a major deformation event that culminated about 660 Ma; episode D-4 makes up part of a later event about 620 Ma. The bulk of the gold-bearing veins in the district are located in D-2 and D-3 structures. D-1 veins consist of thin quartz veins in phyllite. D-2 veins are located in throughgoing, steeply dipping sinistral shear zones and in the crests of folds along the shears. D-3 veins, typically associated with carbonate alteration, are concentrated in small thrust faults that in places modify earlier D-2 shears. Umm al Qurayyat, the largest deposit in the district (155,634 metric tons averaging 3.8 g/t gold), comprises shallowly to moderately steeply clipping sheeted quartz veins in the hanging wall of a D-3 thrust in basaltic andesite and dacite. It is center ed on an inner sericite alteration zone and an outer orange-weathering carbonate alteration zone. Structural evidence indicates that sericite alteration was contemporaneous with D-2 deformation, predating the main quartz veining event, whereas carbonate alteration was contemporary with D-3 thrusting and emplacement of the deposit's principal gold-bearing quartz veins. Quartz at Umm al Qurayyat contains an average of 3.1 g/t gold and sericite-altered wall rock contains an average of 3.9 g/t. Basaltic country lock outside tile deposit contains as much as 1 g/t gold, tile higher grades occurring adjacent to the prospect. C1 MINIST MINERAL RESOURCES,JEDDAH,SAUDI ARABIA. US GEOL SURVEY MISSION,JEDDAH,SAUDI ARABIA. US GEOL SURVEY,RESTON,VA 22092. NR 34 TC 3 Z9 3 U1 0 U2 2 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1995 VL 90 IS 8 BP 2262 EP 2273 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF903 UT WOS:A1995UF90300009 ER PT J AU Eaton, GF Criss, RE Fleck, RJ Bond, WD Cleland, RW Wavra, CS AF Eaton, GF Criss, RE Fleck, RJ Bond, WD Cleland, RW Wavra, CS TI Oxygen, carbon, and strontium isotope geochemistry of the sunshine mine, Coeur d'Alene mining district, Idaho SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID FRACTIONATION; MONTANA; ORIGIN; WATERS AB The Pb-Ag ores of the Sunshine mine, located in tile Coeur d'Alene mining district of northern Idaho, occur within steeply dipping, tabular, west-northwest trending veins of siderite gangue, that crosscut the overturned northern limb of the Big Creek anticline. The delta(13)C(PDB) (9.9 to -6.4 parts per thousand) and delta(18)O(SMOW) (13.1-17.7 parts per thousand) values of the siderites vary in a proportion of about 1:2, but siderites with delta(18)O greater than or equal to 16 exhibit a slope close to the 1:4 trend expected for a system with variable temperature, whereas no correlation is evident for siderites with delta(18)O < 16. The delta(18)O values of crosscutting quartz veins (13.4-15.5) and the surrounding wall rocks (10.7-15.5) are several per mil too low to be in isotopic equilibrium with tl-le siderite at the temperature of similar to 325 degrees C determined from fluid inclusion studies. At this temperature the calculated delta(18)O values for the precipitating fluids range from 7.8 to 12.4 for the siderite and 6.9 to 8.9 for the quartz. The high delta(18)O values calculated for these fluids reflect their exchange with the high O-18 metasedimentary rocks of the Belt Super group in higher temperature fluid source regions. Detailed sample traverses across two 1- to 3-m-mide siderite veins show that il)some veins are composite, containing materials deposited at different times or in different places which were juxtaposed by subsequent, vein-parallel faulting; (2) siderite in structurally simple veins is most enriched in C-13 and O-18 adjacent to the walls, resulting in U-shaped spatial trends; and (3) the delta(18)O values of metasedimentary wall rocks are substantially lower than those of the siderite in the veins and increase adjacent to them. These small-scale variations account for the lack of a simple relationship between delta(18)O and depth in the vein systems. These data also indicate that the vein fluids were hotter and considerably higher in O-18 than the fluids in equilibrium with adjacent wall rock. The progressive O-18 decrease from the margins to the centers of the siderite veins, further decreasing into the early crosscutting quartz veins, probably represents a progressive increase in the temperature of deposition but could also represent variations in fluid source in an evolving system. The dispersion of delta(13)C values for samples with delta(18)O < 16 per mil may be the result of late-stage explosive pressure release and CO2 effervescence during fluid decompression, when fissure filling was nearly complete. The structural simplicity of the veins and the primary hydrothermal character of tile stable isotope variations argue against postdepositional deformation and metamorphism. Stable isotope and strontium isotope data support the interpretation that ore deposition occurred during the Late Cretaceous or early Tertiary as the result of metamorphic hydrothermal processes associated with regional compression and the formation of major granitic batholiths. C1 UNIV CALIF DAVIS,DEPT GEOL,DAVIS,CA 95616. WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130. US GEOL SURVEY,MENLO PK,CA 94025. SUNSHINE PRECIOUS MET INC,KELLOGG,ID 83837. NR 36 TC 18 Z9 20 U1 1 U2 1 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1995 VL 90 IS 8 BP 2274 EP 2286 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF903 UT WOS:A1995UF90300010 ER PT J AU Gibson, PC McKee, EH Noble, DC Swanson, KE AF Gibson, PC McKee, EH Noble, DC Swanson, KE TI Timing and interrelation of magmatic, tectonic, and hydrothermal activity at the Orcopampa district, southern Peru SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID ACID-SULFATE; DEPOSITS; CALDERA; ANDES; MINERALIZATION; DEFORMATION; EVOLUTION; VOLCANISM; COLORADO; SYSTEM C1 UNIV NEVADA,MACKAY SCH MINES,RENO,NV 89557. US GEOL SURVEY,MENLO PK,CA 94025. NR 68 TC 12 Z9 12 U1 0 U2 4 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1995 VL 90 IS 8 BP 2317 EP 2325 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF903 UT WOS:A1995UF90300014 ER PT J AU Rye, RO Stoffregen, RE AF Rye, RO Stoffregen, RE TI Jarosite-water oxygen and hydrogen isotope fractionations: Preliminary experimental data SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID ALUNITE; SULFATE C1 SO METHODIST UNIV,DEPT GEOL SCI,DALLAS,TX 75275. RP Rye, RO (reprint author), US GEOL SURVEY,MAIL STOP 963,DENVER,CO 80225, USA. NR 23 TC 14 Z9 14 U1 0 U2 5 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 1995 VL 90 IS 8 BP 2336 EP 2342 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF903 UT WOS:A1995UF90300017 ER PT J AU BASSETT, RL BUSZKA, PM DAVIDSON, GR CHONGDIAZ, D AF BASSETT, RL BUSZKA, PM DAVIDSON, GR CHONGDIAZ, D TI IDENTIFICATION OF GROUNDWATER SOLUTE SOURCES USING BORON ISOTOPIC COMPOSITION SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ADSORPTION; GEOCHEMISTRY; ALUMINUM; EXCHANGE; OXIDE AB In a long-term evaluation of the injection of treated wastewater into an alluvial aquifer near El Paso, TX, the boron (B) concentration and B stable isotopic values were investigated as potential intrinsic tracers of recharge-water source. The B stable isotopic values (delta(11)B) of background groundwater (14 parts per thousand) and water from anthropogenic sources such as treated municipal wastewater (6-10 parts per thousand) and irrigation-affected water (> 40 parts per thousand) were distinctly different. The B concentrations in combination with the B stable isotope values distinguished these water types and natural saline water as sources of recharge to groundwater. Boron is suited for use as a conservative tracer in groundwater because of its high solubility in aqueous solution (predominantly as boric acid), its natural presence in nearly all water, and the lack of effects by evaporation or volatilization, by oxidation-reduction reactions, or by mineral precipitation or dissolution in all but extremely saline waters. The variability of any observed isotopic ratio in groundwater can be from several processes, such as variability in the B source, mixing, and partitioning reactions, including sorption, which cause isotopic fractionation. For rocks and minerals, a range in delta(11)B values of more than 70 parts per thousand has been reported. Water sources sampled to date have a similarly broad range. In this injection test, B concentrations in all samples were below 1 mg/l, and differences between individual sources of salinity were indistinct based on analytical concentration alone. In contrast, a hypothetical, nonlinear mixture between solutions with different delta(11)B values and different B concentrations demonstrated a detectable isotopic shift for smalt volume percent contributions of the source water with the largest boron concentration. The Hueco Bolson aquifer at the injection site is geologically heterogeneous, and the cost to establish a sufficient density of monitoring wells to describe the flow of injected water in groundwater is prohibitive. For this and other sites, chemical and isotopic tracers such as B and delta(11)B may be used to identify the influence of various water sources with potentially adverse environmental consequences. C1 US GEOL SURVEY,INDIANAPOLIS,IN 46278. RP BASSETT, RL (reprint author), UNIV ARIZONA,DEPT HYDROL & WATER RESOURCES,TUCSON,AZ 85721, USA. NR 28 TC 66 Z9 68 U1 0 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC PY 1995 VL 29 IS 12 BP 2915 EP 2922 DI 10.1021/es00012a005 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TJ354 UT WOS:A1995TJ35400021 PM 22148196 ER PT J AU HARVEY, JW CHAMBERS, RM HOELSCHER, JR AF HARVEY, JW CHAMBERS, RM HOELSCHER, JR TI PREFERENTIAL FLOW AND SEGREGATION OF POREWATER SOLUTES IN WETLAND SEDIMENT SO ESTUARIES LA English DT Article; Proceedings Paper CT Symposium on Pulsed Ecosystems - A New Paradigm/Estuarine-Research-Federation Meeting CY NOV, 1993 CL HILTON HEAD ISL, SC SP Estuarine Res Federat ID SALT-MARSH SEDIMENTS; PORE-WATER; TIDAL MARSHES; NUTRIENT; TRANSPORT; FLUXES; GROUNDWATER; ESTUARIES; DYNAMICS; SOILS AB Sediment macropores (with effective diameters larger than 100 mu m) comprise 11% of the hulk sediment volume in a tidal freshwater wetland vegetated with Peltandra virginica. In order to determine effects of macroporous sediment structure on solute transport, we conducted a solute tracer experiment in the sediment. The effective transport volume (theta(eff), the volume of sediment through which solute was transported normalized to sediment hulk volume) was 0.15 cm(3) cm(-3), which is considerably smaller than the total pore space that is potentially available for transport (porosity of sediment is 0.63 cm(3) cm(-3)). A mean transport time of 13 d was required to flush preferential flow paths in Peltandra hummocks; hydrologic turnover of the volumetrically dominant matrix pores (0.53 cm(3) cm(-3)) was apparently much slower. Based on porewater sampler design and hydrological principles, we suggest that N-2-purged tension solution samplers and diffusion equilibrators preferentially sample porewater from macropore and matrix domains, respectively. Dissolved ammonium and orthophosphate concentrations were three-fold higher in matrix pores compared to macropores, which is consistent with our finding that more rapid hydrological flushing occurred in macropores compared to matrix pores, Further evaluation of porewater sampler designs in macroporous sediment is needed to improve studies of hydrologic transport and biogeochemical cycling in wetlands. C1 FAIRFIELD UNIV,DEPT BIOL,FAIRFIELD,CT 06430. UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. RP HARVEY, JW (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MAIL STOP 496,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Harvey, Judson/L-2047-2013 OI Harvey, Judson/0000-0002-2654-9873 NR 38 TC 31 Z9 32 U1 2 U2 10 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1995 VL 18 IS 4 BP 568 EP 578 DI 10.2307/1352377 PG 11 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TA813 UT WOS:A1995TA81300004 ER PT J AU Haag, WR Butler, RS Hartfield, PD AF Haag, WR Butler, RS Hartfield, PD TI An extraordinary reproductive strategy in fresh water bivalves: Prey mimicry to facilitate larval dispersal SO FRESHWATER BIOLOGY LA English DT Article ID GLOCHIDIA; UNIONIDAE; MOLLUSCA; VIRGINIA; MUSSELS AB 1. Females of the North American freshwater bivalve Lampsilis perovalis release their larvae, which are obligate parasites on fish, in a discrete mass (superconglutinate) resembling a small fish in shape and coloration. After release, the mass remains tethered to the female by a long, transparent, mucous strand and, in stream currents, displays a darting motion that further mimics a small fish. 2. Release of superconglutinates was observed in March and April at water temperatures of 14-17 degrees C. However, superconglutinates detached from the parent mussel were observed from March to June at water temperatures of 11-26 degrees C, indicating that release may occur into the summer. 3. The superconglutinate lure may function to attract a predaceous fish to ingest the mass, ensuring that the larvae are exposed to a suitable host. 4. This reproductive strategy was confirmed recently to occur in a congener, L. subangulata and is suspected to occur in another congener, L. australis. C1 US FISH & WILDLIFE SERV,JACKSONVILLE,FL 32216. US FISH & WILDLIFE SERV,JACKSON,MS 39213. RP Haag, WR (reprint author), US FOREST SERV,FOREST HYDROL LAB,SO RES STN,POB 947,OXFORD,MS 38655, USA. NR 18 TC 40 Z9 41 U1 0 U2 14 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0046-5070 J9 FRESHWATER BIOL JI Freshw. Biol. PD DEC PY 1995 VL 34 IS 3 BP 471 EP 476 DI 10.1111/j.1365-2427.1995.tb00904.x PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA TP034 UT WOS:A1995TP03400006 ER PT J AU BALISTRIERI, LS MURRAY, JW PAUL, B AF BALISTRIERI, LS MURRAY, JW PAUL, B TI THE GEOCHEMICAL CYCLING OF STABLE PB, PB-210, AND PO-210 IN SEASONALLY ANOXIC LAKE SAMMAMISH, WASHINGTON, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID OLIGOTROPHIC LAKE; WATER COLUMN; IRON; MANGANESE; HYPOLIMNION; ADSORPTION; SEAWATER; BALANCE; OCEAN AB The geochemical processes controlling the behavior of stable Pb, Pb-210, and Po-210 in seasonally anoxic Lake Sammamish, Washington were identified from water column distributions and box model calculations. Total (sum of dissolved and particulate) inventories of stable Pb, Pb-210, and Po-210 increased in the whole lake during the latter part of the oxic stage of the lake and were attributed to diffusion from sediments. Large decreases in the total inventories of these elements occurred during the transition from oxic to anoxic conditions, and the lowest inventories were observed during the sulfidic stage of stratification. The cycling of stable Pb and Pb-210 during oxic periods appeared to be linked to Fe cycling while Po-2l0 cycling was more closely linked to the cycling of Mn. The behavior of stable and radioactive Pb and, possibly, Po-210 during anoxia was influenced by sulfur cycling. Thermodynamic calculations indicated that dissolved Pb concentrations might be controlled by PbS precipitation during anoxia. Flux balance calculations during stratification indicated that atmospheric deposition was the major source of both Pb-210 and Po-210 to the lake and fluvial input was more important for Po-210 than for Pb-210. Pb-210 and Po-210 supplied by atmospheric deposition were scavenged and removed by sedimentation from the epilimnion. Residence times with respect to scavenging and sedimentation in the epilimnion were 1-3 and 6-17 days, respectively, for Pb-210 and 9-22 and 9-26 days for Po-210. Model results in the hypolimnion indicated that at certain times the radionuclides diffused out of the sediments and at other times into the sediments. Residence times with respect to sedimentation of particulate nuclides in the hypolimnion were 2-124 days for Pb-210 and 8-48 days for Po-210. The behavior of Pb-210 and Po-210 in Lake Sammamish was compared to that in Bickford Reservoir, Massachusetts. Although the comparison indicated similarities (e.g., links to Fe and Mn cycling, larger scavenging rates for Pb-210 than for Po-210, the major differences between the systems were that atmospheric inputs were greater than fluvial inputs, activities of the radionuclides were lower, and the presence of sulfide in the hypolimnion during anoxia affected the cycling of stable Pb, Pb-210, and Po-210 in, Lake Sammamish. C1 UNIV WASHINGTON, SCH OCEANOG, SEATTLE, WA 98195 USA. RP BALISTRIERI, LS (reprint author), UNIV WASHINGTON, US GEOL SURVEY, SCH OCEANOG, BOX 357940, SEATTLE, WA 98195 USA. NR 39 TC 28 Z9 28 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC PY 1995 VL 59 IS 23 BP 4845 EP 4861 DI 10.1016/0016-7037(95)00334-7 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TJ546 UT WOS:A1995TJ54600005 ER PT J AU KYTE, FT BOHOR, BF AF KYTE, FT BOHOR, BF TI NICKEL-RICH MAGNESIOWUSTITE IN CRETACEOUS/TERTIARY BOUNDARY SPHERULES CRYSTALLIZED FROM ULTRAMAFIC, REFRACTORY SILICATE LIQUIDS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EARLY SOLAR NEBULA; TERTIARY BOUNDARY; EVAPORATION METAMORPHISM; IMPACT EVENT; CARAVACA; MEXICO; SPAIN; OCEAN; MICROKRYSTITES; SEDIMENTS AB We have found trace inclusions of Ni-rich magnesiowustite within grains of magnesioferrite spinel recovered from Cretaceous/Tertiary boundary sediments from DSDP Site 596, South Pacific (23 degrees 51.20'S, 169 degrees 39.27'W) and DSDP Site 577, North Pacific (32 degrees 26.51'N, 157 degrees 43.40'E). Measured compositions of these inclusions range from (Mg.85Ni.11Fe0.4)O to (Mg.74Ni.09Fe.17)O. Coexisting magnesioferrite and magnesiowustite can only crystallize from ultramafic, refractory, Mg-rich liquids with Mg/Si > 2 (atom ratio). Such liquid compositions cannot form as a result of fractional crystallization and are unknown to occur as a result of terrestrial igneous processes or meteoroid ablation. We infer that these minerals crystallized from liquid droplets that equilibrated with silicate vapor at high temperatures (probably >2300 degrees C), resulting in fractionation of volatile SiO2 from more refractory MgO. The most plausible source of this high-temperature vapor is in the fireball of the major impact event that terminated the Cretaceous. C1 US GEOL SURVEY,DENVER,CO 80225. RP KYTE, FT (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024, USA. NR 50 TC 18 Z9 19 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC PY 1995 VL 59 IS 23 BP 4967 EP 4974 DI 10.1016/0016-7037(95)00343-6 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TJ546 UT WOS:A1995TJ54600013 ER PT J AU Horan, MF Walker, RJ Fedorenko, VA Czamanske, GK AF Horan, MF Walker, RJ Fedorenko, VA Czamanske, GK TI Osmium and neodymium isotopic constraints on the temporal and spatial evolution of Siberian flood basalt sources SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID RE-OS; TRACE-ELEMENT; CRUSTAL CONTRIBUTIONS; TRIASSIC BOUNDARY; CONTINENTAL-CRUST; NORILSK REGION; MANTLE PLUME; SR-ISOTOPE; ND; VOLCANISM AB High-Mg volcanic rocks from the ca. 250 Ma old Siberian Flood Basalt Province (SFBP) were analyzed for their osmium and neodymium isotopic compositions in order to help to constrain source characteristics as the system evolved. Picrites from the Gudchikhinsky suite, the oldest rocks examined, have gamma(Os) of +5.3 to +6.1 and epsilon(Nd) of +3.7 to +4.0. The osmium and neodymium isotopic compositions of these rocks are similar to some modern ocean-island basalts (OIB), consistent with their derivation from a mantle plume, and show little evidence for interaction with either subcontinental lithospheric mantle (SCLM), or the Precambrian Siberian craton through which the parental melts passed. Picrites from the stratigraphically higher Tuklonsky suite have similar gamma(Os) of +3.4 to +6.5, but epsilon(Nd) of -0.9 to -2.6. The similar gamma(Os) but lower epsilon(Nd), for the Tuklonsky picrites as compared with the Gudchikhinsky picrites suggest that some magmas from the same OIB-type, mantle source were contaminated by lithospheric components. The osmium isotopic composition of the Tuklonsky picrites was not significantly affected by this interaction, possibly because Os concentrations in the magmas were substantially greater than those in the contaminant. A differentiated ankaramite flow, associated with the top of the stratigraphically higher Morongovsky suite, has gamma(Os) of +9.8 to +10.2 and epsilon(Nd) of +1.3 to +1.4. The higher gamma(Os) may indicate that the plume source was heterogeneous with respect to osmium isotopic composition, consistent with osmium isotopic measurements in rocks from other plume sources. In contrast to these rocks, Mg-rich, alkaline rocks (meymechites) from the Gull area that erupted much nearer the end of the flood-basalt event have gamma(Os) of -1.2 to -2.6 and epsilon(Nd) of +3.7 to +4.9. These rocks were probably produced by low degrees of partial melting of mantle after the main stages of flood-basalt production. The relatively low gamma(Os) and high epsilon(Nd) for the meymechites, together with a variety of trace-element characteristics, are most consistent with derivation from a mixed source-one that included both the OIB-type source that fed the majority of the flood-basalt system and a major component from the SCLM underlying the Siberian craton. These results, taken together with earlier investigations of the Noril'sk-type ore-bearing intrusions, suggest that much of the SFBP consists dominantly of plume-derived material, until relatively late in the magmatic event, when the SCLM became a significant source of material. C1 US GEOL SURVEY,RESTON,VA 22092. UNIV MARYLAND,DEPT GEOL,COLLEGE PK,MD 20742. TSNIGRI,MOSCOW 113545,RUSSIA. US GEOL SURVEY,MENLO PK,CA 94025. RI Walker, Richard/K-6869-2016 OI Walker, Richard/0000-0003-0348-2407 NR 57 TC 72 Z9 77 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC PY 1995 VL 59 IS 24 BP 5159 EP 5168 DI 10.1016/0016-7037(96)89674-8 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TL898 UT WOS:A1995TL89800010 ER PT J AU PERKINS, ME NASH, WP BROWN, FH FLECK, RJ AF PERKINS, ME NASH, WP BROWN, FH FLECK, RJ TI FALLOUT TUFFS OF TRAPPER-CREEK, IDAHO - A RECORD OF MIOCENE EXPLOSIVE VOLCANISM IN THE SNAKE RIVER PLAIN VOLCANIC PROVINCE SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID WESTERN UNITED-STATES; METAMORPHIC CORE COMPLEXES; NORTHERN GREAT-BASIN; YELLOWSTONE PLATEAU; CRUSTAL STRUCTURE; SILICIC MAGMA; TEMPERATURE; RHYOLITES; FIELD; ASH AB A 900-m-thick section of tuffaceous sedimentary rock, vitric fallout tuff, and ash-flow tuff is well exposed along Trapper Creek in south-central Idaho, This section provides nearly continuous exposure through the fill of the Goose Creek basin, a major north-trending Miocene extensional basin located along the southern margin of the Snake River Plain volcanic province (SRPVP), Some 51 separate units of vitric fallout tuff are recognized in the Trapper Creek section, Petrographic and chemical characteristics of these vitric tuffs indicate that most are from SRPVP sources, New Ar-40/Ar-39 laser-fusion dating, along with prior isotopic age determinations, show that the Trapper Creek tuffs span the period ca, 13.9-8.6 Ma. Chemical correlation indicates that fallout tuffs in the central part of the Trapper Creek section (12.5-10.0 Ma) are from sources in the Bruneau-Jarbidge volcanic field of the SRPVP centered approximate to 200 km west of Trapper Creek. Underlying fallout tuffs may have had sources in the Owyhee-Humboldt field of the SRPVP centered approximate to 200 km west of Trapper Creek, while overlying fallout tuffs, interlayered with several ash-flow tuffs, had a relatively proximal source, possibly in the proposed Twin Falls volcanic field centered approximate to 60 km north of Trapper Creek. The Trapper Creek tuffs provide insight into the characteristics of explosive silicic volcanism within the SRPVP during middle-late Miocene time, From ca, 13.9 to ca, 9.5 Ma, major eruptions (those depositing greater than or equal to 1.5 m of fallout tuff) were frequent (about one event per 200 ty,); their products display a trend toward the eruption of progressively less evolved, higher temperature silicic magma after 12.5 Ma, This trend to higher temperature eruptions, termed the Cougar Point ''flare-up,'' culminated in the eruption of high-temperature (approximate to 1000 degrees C), plagioclase-rich magma during the period 10.5-9.5 Ma, In contrast to these eruptions, later (<7.0 Ma) major silicic eruptions within the SRPVP were characterized by the lower temperature (approximate to 850 degrees C) of the erupted magma and by the longer intervals (about one event per approximate to 500-600 k.y,) between eruptions. Variations in the character of SRPVP explosive silicic eruptions may reflect changes in the structure, composition, or state of stress in the crust beneath the eastward propagating SRPVP, or, perhaps, changes in the Yellowstone hot-spot plume that may drive the SRPVP volcanism. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP PERKINS, ME (reprint author), UNIV UTAH, DEPT GEOL & GEOPHYS, SALT LAKE CITY, UT 84112 USA. NR 68 TC 88 Z9 88 U1 0 U2 7 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0016-7606 EI 1943-2674 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD DEC PY 1995 VL 107 IS 12 BP 1484 EP 1506 DI 10.1130/0016-7606(1995)107<1484:FTOTCI>2.3.CO;2 PG 23 WC Geosciences, Multidisciplinary SC Geology GA TG953 UT WOS:A1995TG95300008 ER PT J AU SHINOHARA, H KAZAHAYA, K LOWENSTERN, JB AF SHINOHARA, H KAZAHAYA, K LOWENSTERN, JB TI VOLATILE TRANSPORT IN A CONVECTING MAGMA COLUMN - IMPLICATIONS FOR PORPHYRY MO MINERALIZATION SO GEOLOGY LA English DT Article ID RHEOLOGY AB We propose that convection in a column of silicic magma allows transport of volatile components from large (>50 km(3)) magma chambers to the sites of shallow (similar to 3 km) porphyry-type Mo deposits. Using constraints from the Henderson and Pine Grove systems, we show that even at temperatures as low as 700 degrees C, a granitic magma, with 30 vol% phenocrysts can flow through a magma column with a 150 m radius at a rate >10 km(3)/yr-enough magma to contribute the Mo necessary to form an ore deposit in a geologically reasonable time frame. This process requires an efficient mechanism for bubble separation at the top of the magma column to produce degassd magma that can descend down through the column. It also requires slow rates of crystallization in the silicic magma, consistent with experimental studies. Hydrothermal fluids released from the convecting magma column can explain many geologic features of the deposits. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP SHINOHARA, H (reprint author), GEOL SURVEY JAPAN,1-1-3 HIGASHI,TSUKUBA,IBARAKI 305,JAPAN. RI Kazahaya, Kohei/P-6140-2016; OI Lowenstern, Jacob/0000-0003-0464-7779 NR 18 TC 73 Z9 87 U1 2 U2 25 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD DEC PY 1995 VL 23 IS 12 BP 1091 EP 1094 DI 10.1130/0091-7613(1995)023<1091:VTIACM>2.3.CO;2 PG 4 WC Geology SC Geology GA TG965 UT WOS:A1995TG96500009 ER PT J AU BEHRENDT, JC BLANKENSHIP, DD DAMASKE, D COOPER, AK AF BEHRENDT, JC BLANKENSHIP, DD DAMASKE, D COOPER, AK TI GLACIAL REMOVAL OF LATE CENOZOIC SUBGLACIALLY EMPLACED VOLCANIC EDIFICES BY THE WEST ANTARCTIC ICE-SHEET SO GEOLOGY LA English DT Article AB Local maxima of the horizontal gradient of pseudogravity from closely spaced aeromagnetic surveys over the Ross Sea, northwestern Ross Ice Shelf, and the West Antarctic ice sheet, reveal a linear magnetic rift fabric and numerous subcircular, high-amplitude anomalies, Most of these anomalies have sources that probably resulted from late Cenozoic volcanism, Some of these volcanic structures penetrate the Neogene sediments beneath the deglaciated continental shelf and are present at the base of the present grounded ice sheet and beneath the ice shelf, Geophysical data indicate two or three youthful volcanic edifices at widely separated areas beneath the sea and ice cover in the West Antarctic rift system. In contrast, we suggest glacial removal of edifices of volcanic sources of many more anomalies, Magnetic models, controlled by marine seismic reflection and radar ice-sounding data, allow us to infer that glacial removal of the associated late Cenozoic volcanic edifices (probably debris, comprising pillow breccias, and hyaloclastites) has occurred essentially concomitantly with their subglacial eruption, ''Removal'' of unconsolidated volcanic debris erupted beneath the ice is probably a more appropriate term than ''erosion,'' given its fragmented, ice-contact origin, The exposed volcanoes may have been protected from erosion by the surrounding ice sheet because of more competent rock or high elevation above the ice sheet, Glacial removal may be the general case; exposed late Cenozoic volcanic peaks and outcrops, consisting primarily of flows, which erupted during Antarctic glacial conditions since similar to 30 Ma, may be the exceptions, The volume of the exposed volcanoes is small in contrast to the much greater volume (>10(6) km(3)) of late Cenozoic magmatic rock remaining at volcanic centers beneath the continental shelf, Ross Ice Shelf, and West Antarctic ice sheet. C1 UNIV TEXAS,INST GEOPHYS,AUSTIN,TX 78759. GERMAN FED INST GEOSCI & NAT RESOURCES,HANNOVER,GERMANY. US GEOL SURVEY,MENLO PK,CA 94025. RP BEHRENDT, JC (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. RI Blankenship, Donald/G-5935-2010 NR 15 TC 18 Z9 18 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD DEC PY 1995 VL 23 IS 12 BP 1111 EP 1114 DI 10.1130/0091-7613(1995)023<1111:GROLCS>2.3.CO;2 PG 4 WC Geology SC Geology GA TG965 UT WOS:A1995TG96500014 ER PT J AU HANSEN, VL OLIVER, DH DUSELBACON, C AF HANSEN, VL OLIVER, DH DUSELBACON, C TI HOT-SIDE-UP AUREOLE IN SOUTHWEST YUKON AND LIMITS ON TERRANE ASSEMBLY OF THE NORTHERN CANADIAN CORDILLERA - COMMENT SO GEOLOGY LA English DT Note ID TESLIN SUTURE ZONE; TANANA TERRANE; EVOLUTION; ALASKA C1 US GEOL SURVEY,MENLO PK,CA 94025. RP HANSEN, VL (reprint author), SO METHODIST UNIV,DEPT GEOL SCI,DALLAS,TX 75275, USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD DEC PY 1995 VL 23 IS 12 BP 1151 EP 1152 DI 10.1130/0091-7613(1995)023<1151:HSUAIS>2.3.CO;2 PG 2 WC Geology SC Geology GA TG965 UT WOS:A1995TG96500025 ER PT J AU Grimm, MM Wohl, EE Jarrett, RD AF Grimm, MM Wohl, EE Jarrett, RD TI Coarse-sediment distribution as evidence of an elevation limit for flash flooding, Bear Creek, Colorado SO GEOMORPHOLOGY LA English DT Article ID GEOMORPHOLOGY; AUSTRALIA; DEPOSITS; GORGE AB Bear Creek is a tributary of the South Platte River in central Colorado. The stream flows east from an elevation of 4348 m at the Continental Divide to the mountain front at 1670 m. It thus encompasses the 2300 m elevation limit for substantial rainfall flooding in the Colorado Front Range proposed by Jarrett. Maximum paleoflood discharges estimated from flood deposits at four sites along Bear Creek demonstrate a consistent decrease in unit discharge with increasing elevation and support the hypothesis of an upper elevation limit for rainfall floods. The unit discharge values were used to explain coarse-sediment distribution along Bear Creek. Measurements of coarse-grained channel sediment at 19 sites along the creek indicate a decrease in particle size in flood deposits with increasing elevation, as well as a decrease in the size of clasts introduced to the main channel along tributaries. These changes in grain size are hypothesized to reflect changes in the competence of channel transport as a result of snowmelt-dominated versus rainfall-dominated discharge regimes above and below 2100 m elevation. Calculations of flow competence versus entrainment thresholds for the deposits may support this interpretation. One of the geomorphic implications of the elevation limit on Bash flooding is a reversal of the usual downstream-fining trend in coarse channel sediments. C1 US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,DENVER,CO 80225. COLORADO STATE UNIV,DEPT EARTH RESOURCES,FT COLLINS,CO 80523. NR 50 TC 25 Z9 25 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD DEC PY 1995 VL 14 IS 3 BP 199 EP 210 DI 10.1016/0169-555X(95)00037-6 PG 12 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA TT679 UT WOS:A1995TT67900001 ER PT J AU Poag, CW AF Poag, CW TI Modern meteoritics SO GEOTIMES LA English DT Letter RP Poag, CW (reprint author), US GEOL SURVEY,384 WOODS HOLE RD,WOODS HOLE,MA 02543, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD DEC PY 1995 VL 40 IS 12 BP 4 EP 4 PG 1 WC Geosciences, Multidisciplinary SC Geology GA VT036 UT WOS:A1995VT03600001 ER PT J AU LUNTZ, SJ BUTMAN, B WILLIAMS, AJ AF LUNTZ, SJ BUTMAN, B WILLIAMS, AJ TI COMPARISON OF BASS AND VACM CURRENT MEASUREMENTS DURING STRESS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CURRENT-METER; SHELF AB Current measurements from a vector-averaging current meter (VACM) on a subsurface mooring and a benthic acoustic stress sensor(BASS) on a bottom tripod are compared to assess their relative accuracy. The instruments were deployed off northern California at a midshelf site (water depth approximately 90 m) as part of the STRESS (Sediment Transport Events on Shelves and Slopes) field program. The subsurface mooring and bottom tripod were within a few hundred meters of each other, with the BASS 5.0 m and the VACM 6.7 m above the bottom, during two tripod deployments of 49 and 32 days in the winter of 1988/89. Speed differences between the VACM and BASS current observations have a mean of 0.2 cm s(-1) and a standard deviation of 1.2 cm s(-1). If the mean speed profile is logarithmic, the expected mean speed difference due to the vertical separation is about 0.4 cm s(-1). The avenge speed difference between the VACM and BASS increases as near-bottom wave orbital velocities get large relative to hourly averaged currents, consistent with laboratory studies of VACMs in oscillating flows. Direction differences have a mean of 1 degrees and standard deviations of about 5 degrees for speeds greater than 10 cm s(-1). The relative accuracy of the corresponding velocity measurements is +/-2 cm s(-1) (mean differences less than 0.6 cm s(-1) and standard deviations of about 1 cm s(-1)). The equations used to convert VACM rotor rotation rates to current speed are based on a calibration study by Woodward and Appell rather than one based on a study by Cherriman that is routinely used at the Woods Hole Oceanographic Institution. The former yields closer agreement between the BASS and VACM speed measurements during STRESS(mean speed difference 0.2 cm s(-1) versus 1.4 cm s(-1)). C1 US GEOL SURVEY,WOODS HOLE,MA 02543. RP LUNTZ, SJ (reprint author), WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,CLARK LAB 319,WOODS HOLE,MA 02543, USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1995 VL 12 IS 6 BP 1328 EP 1337 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA TE756 UT WOS:A1995TE75600013 ER PT J AU JENNINGS, AE NELSON, AR SCOTT, DB ARAVENA, JC AF JENNINGS, AE NELSON, AR SCOTT, DB ARAVENA, JC TI MARSH FORAMINIFERAL ASSEMBLAGES IN THE VALDIVIA ESTUARY, SOUTH-CENTRAL CHILE, RELATIVE TO VASCULAR PLANTS AND SEA-LEVEL SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE HOLOCENE SEA-LEVEL CHANGES; SALT-MARSH FORAMINIFERA; CHILEAN COAST; INTERTIDAL ZONATION; LITTORAL PALEOENVIRONMENTS; COASTAL PALEOSEISMOLOGY; TROCHAMMINITA SALSA ID OREGON TIDAL MARSHES; FRASER-RIVER DELTA; ZONATION; HISTORY AB High marsh foraminiferal assemblages are distinct from those of the low marsh, mud flat, and upland floral zones in two transects across tidal marshes in the Valdivia estuary of south-central Chile. Assemblages from the high marsh, mapped on the basis of vascular plant communities, consist mostly of Trochamminita salsa and have higher concentrations of foraminifera than samples from lower intertidal zones. Fossil assemblages in a core that records the sudden subsidence of the Valdivia estuary during the great earthquake of 1960 cannot be used to estimate the amount of sudden sea-level rise during the earthquake because the core contains only low marsh/mud dat assemblages, which are indistinguishable from one another. The 0.8-0.5 m vertical range of the high marsh assemblage zone, and the undefined ranges of the low marsh/mud Bat and upland zones also limit the precision of estimates of relative sealevel change. More precise estimates of the amount of land-level change during past great earthquakes in this region will require identification of assemblage zones with narrower elevational ranges. The Valdivia high marsh foraminiferal assemblages differ dramatically from other reported high marsh assemblages from the mid-latitude Americas in being dominated by Trochamminita salsa. Our study of the large populations of the genus Trochamminita Cushman and Bronnimann encountered along the transects indicates that the two species of Trochamminita that have been described previously should be combined into the single species, Trochamminita salsa. C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. US GEOL SURVEY,DENVER,CO 80225. DALHOUSIE UNIV,CTR MARINE GEOL,HALIFAX,NS B3H 3J5,CANADA. UNIV CHILE,FAC CIENCIAS,DEPT BIOL,SECC BOT,SANTIAGO,CHILE. RP JENNINGS, AE (reprint author), UNIV COLORADO,INSTAAR,CAMPUS BOX 450,BOULDER,CO 80309, USA. NR 60 TC 34 Z9 40 U1 1 U2 6 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1995 VL 11 IS 1 BP 107 EP 123 PG 17 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA QG342 UT WOS:A1995QG34200006 ER PT J AU FLETCHER, CH RICHMOND, BM BARNES, GM SCHROEDER, TA AF FLETCHER, CH RICHMOND, BM BARNES, GM SCHROEDER, TA TI MARINE FLOODING ON THE COAST OF KAUAI DURING HURRICANE INIKI - HINDCASTING INUNDATION COMPONENTS AND DELINEATING WASHOVER SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE HURRICANE INIKI; HAWAII; KAUAI; COASTAL OVERWASH; FEMA V-ZONE; FIRM; DEBRIS LINE; HINDCAST ANALYSIS ID NATURAL BEACH; SWASH AB The right frontal quadrant of Hurricane Iniki crossed the southeast coast of Kaua'i on the afternoon of September 11, 1992 and produced marine overwash with excursion distances of approximately 20-250 m and elevations in the range 4-9 m (mllw). Using a combination of field data, empirical relationships, and theory, we estimate that the effective maximum sustained wind velocity (V-theta max) was in the range 52.4+/-2 m/s. We also analyze the meteorological and oceanographic components of marine flooding under the right frontal quadrant of the storm. Overwash was principally a function of eye-relative position and orientation of the coast, tan theta (slope), the friction-controlled wave run-up, and the wave set-up. Maximum overwash was adjacent to a major bathymetric channel and a slightly embayed coastline which reduced wave-energy dissipation in the nearshore, affording greater landward translation of deep-water wave characteristics. Total combined calculated overwash on the south shore of Kaua'i at Kukuiula (similar to 5.2 m mllw) is the sum of pressure set-up (0.39 m), wave set-up (1 m), wind stress set-up (0.06 m), run-up (2.9 m) and tidal stage (similar to 0.8 m). Measured debris-line and still-water mark elevations there ranged from 3.91-5.90 m (mllw). To the east on the steeper Koloa Landing coast, the calculated overwash components equaled approximately 6.6 m (mllw), and measured debris-line elevations ranged from 6.84 to 9.16 m (mllw). We present and discuss maps of the Iniki debris line relative to the FEMA V-zone and 100-yr flood zone, and major transportation arteries along the shoreline at five major coastal population centers on Kaua'i. C1 US GEOL SURVEY,PACIFIC MARINE GEOL BRANCH,MENLO PK,CA 94025. UNIV HAWAII,DEPT METEOROL,HONOLULU,HI 96822. RP FLETCHER, CH (reprint author), UNIV HAWAII,DEPT GEOL & GEOPHYS,2525 CORREA RD,HONOLULU,HI 96822, USA. NR 17 TC 33 Z9 34 U1 1 U2 3 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1995 VL 11 IS 1 BP 188 EP 204 PG 17 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA QG342 UT WOS:A1995QG34200012 ER PT J AU KNEBEL, HJ CIRCE, RC AF KNEBEL, HJ CIRCE, RC TI SEA-FLOOR ENVIRONMENTS WITHIN THE BOSTON HARBOR MASSACHUSETTS BAY SEDIMENTARY SYSTEM - A REGIONAL SYNTHESIS SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE SEDIMENTARY ENVIRONMENTS; ESTUARINE AND COASTAL SEDIMENTATION; ESTUARINE AND COASTAL PROCESSES; SEA-FLOOR TEXTURE ID INNER SHELF; MAINE; ESTUARY; GULF AB Modern seafloor sedimentary environments within the glaciated, topographically complex Boston Harbor and Massachusetts Bay area have been interpreted and mapped from an extensive collection of sidescan sonar records and supplemental marine geologic data. Three categories of environments are present that reflect the dominant long-term processes of erosion or nondeposition, deposition, and sediment reworking. (1) Environments of erosion or nondeposition comprise exposures of bedrock, glacial drift, coarse lag deposits, and possibly coastal plain rocks that contain sediments (where present) ranging from boulder fields to gravelly sands and occur in areas of relatively strong currents. (2) Environments of deposition contain fine-grained sediments ranging from muddy sands to muds that have accumulated in areas of predominantly weak bottom currents. (3) Environments of sediment reworking contain patches with textures ranging from sandy gravels to muds that have been produced by a combination of erosion and deposition in areas with variable bottom currents. The distribution of sedimentary environments across the Boston Harbor-Massachusetts Bay area is extremely patchy. Locally, this patchiness is due either to modifications of bottom-currentstrength (caused by the irregular topography and differences in water depth) or to small-scale changes in the supply of fine-grained sediments. Regional patchiness, however, reflects differences in geologic and oceanographic conditions among the estuarine, inner shelf, and basinal parts of the sedimentary system. The estuarine part of the system (Boston Harbor) is a depositional trap for fine-grained sediments because it is protected from large waves, has generally weak and variable tidal currents, and receives a large supply of fine-grained detritus from natural and anthropogenic sources. The inner shelf, on the other hand, is largely an area of erosion or nondeposition due to sediment removal and redistribution during past sea-level changes, to sediment resuspension and winnowing by modern waves and currents, and to an inadequate supply of fine-grained sediments. The basinal part of the system (Stellwagen Basin) is mainly a tranquil depositional environment in which fine-grained sediments from several potential sources settle through the water column and accumulate under weak bottom currents. This study indicates areas within the Boston Harbor-Massachusetts Bay sedimentary system where tine-grained sediments and associated contaminants are likely to be either moved or deposited. It also provides a guide to the locations and variability of benthic habitats. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP KNEBEL, HJ (reprint author), US GEOL SURVEY,ATLANTIC MARINE GEOL BRANCH,WOODS HOLE,MA 02543, USA. NR 67 TC 13 Z9 13 U1 0 U2 4 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1995 VL 11 IS 1 BP 230 EP 251 PG 22 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA QG342 UT WOS:A1995QG34200015 ER PT J AU Hickman, SH Younker, LW Zoback, MD Cooper, GA AF Hickman, SH Younker, LW Zoback, MD Cooper, GA TI The san Andreas fault zone drilling project: Scientific objectives and technological challenges SO JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID HEAT-FLOW; STRESS; PRESSURE; FRICTION; STATE; EARTHQUAKES; CALIFORNIA AB We are leading a new international initiative to conduct scientific drilling within the San Andreas fault zone at depths of up to 10 km. This project is motivated by the need to understand the physical and chemical processes operating within the fault zone and to answer fundamental questions about earthquake generation along major plate-boundary faults. Through a comprehensive program of coring, fluid sampling, downhole measurements, laboratory experimentation, and long-term monitoring, we hope to obtain critical information on the structure, composition, mechanical behavior and physical state of the San Andreas fault system at depths comparable to the nucleation zones of great earthquakes. The drilling, sampling and observational requirements needed to ensure the success of this project are stringent. These include: 1) drilling stable vertical holes to depths of about 9 km in fractured rock at temperatures of up to 300 degrees C; 2) continuous coring and completion of inclined holes branched off these vertical boreholes to intersect the fault at depths of 3, 6, and 9 km; 3) conducting sophisticated borehole geophysical measurements and fluid/rock sampling at high temperatures and pressures; and 4) instrumenting some or all of these inclined core holes for continuous monitoring of earthquake activity, fluid pressure, deformation and other parameters for periods of lip to several decades. For all of these tasks, because of the overpressured clay-rich formations anticipated within the fault zone at depth, we expect to encounter difficult drilling, coring and hole-completion conditions in the region of greatest scientific interest. RP Hickman, SH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 30 TC 2 Z9 2 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0195-0738 J9 J ENERG RESOUR-ASME JI J. Energy Resour. Technol.-Trans. ASME PD DEC PY 1995 VL 117 IS 4 BP 263 EP 270 DI 10.1115/1.2835422 PG 8 WC Energy & Fuels SC Energy & Fuels GA TY073 UT WOS:A1995TY07300003 ER PT J AU FEND, SV CARTER, JL AF FEND, SV CARTER, JL TI THE RELATIONSHIP OF HABITAT CHARACTERISTICS TO THE DISTRIBUTION OF CHIRONOMIDAE (DIPTERA) AS MEASURED BY PUPAL EXUVIAE COLLECTIONS IN A LARGE RIVER SYSTEM SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article ID STREAM; CLASSIFICATION; POLLUTION; PATTERNS AB Floating chironomid pupal exuviae were collected throughout the Yakima River (Washington, USA) and tributaries in 1989 and 1990. Al samples were taken during the October-November low-now season and most sites were visited once with a sampling effort of approximately 10 minutes. Sampled stream segments ranged from 3rd to 7th order and elevation ranged from 140-1200 m. The total number of taxa distinguished in 77 samples was 150 with a mean of 24 per site. Species richness was not highly correlated with stream order or elevation. An ecological gradient defined by ordinating the taxa by site data was highly correlated with site elevation (r=.93). Comparison with published attributes of chironomid genera suggested that temperature regime was a dominant environmental variable controlling chironomid distribution in this basin. However, since most measured habitat variables were associated with altitude, their effects could not be separated. Cluster analysis of taxa by site data resulted in groupings that distinguished montane from valley sites and agricultural drains from other valley sites. Differences in species composition between moderately enriched agricultural drains and less-impacted sites were minor compared with the underlying elevation gradient. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MAILSTOP 465, MENLO PK, CA 94025 USA. NR 35 TC 5 Z9 7 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0270-5060 EI 2156-6941 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD DEC PY 1995 VL 10 IS 4 BP 343 EP 359 DI 10.1080/02705060.1995.9663457 PG 17 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TJ404 UT WOS:A1995TJ40400005 ER PT J AU Allen, CM Wooden, JL Howard, KA Foster, DA Tosdal, RM AF Allen, CM Wooden, JL Howard, KA Foster, DA Tosdal, RM TI Sources of the Early Cretaceous plutons in the Turtle and West Riverside mountains, California: Anomalous Cordilleran Interior intrusions SO JOURNAL OF PETROLOGY LA English DT Article DE Cordilleran Interior; Cretaceous; Mojave; pseudochron; Turtle Mountains ID METAMORPHIC CORE COMPLEXES; SOUTHWESTERN UNITED-STATES; EASTERN MOJAVE DESERT; FELDSPAR AGE SPECTRA; NORTHERN-GREAT-BASIN; SOUTHEASTERN CALIFORNIA; ISOTOPIC EVIDENCE; PROTEROZOIC DIABASE; CRUSTAL STRUCTURE; MULE MOUNTAINS AB Ages and initial isotopic ratios of Early Cretaceous (similar to 100 Ma) plutons of the Cordilleran Interior in the southern Turtle and West Riverside mountains distinguish then from Late Cretaceous plutons in surrounding ranges in the eastern Mojave Desert. Furthermore, the studied plutons have isotopic and geochemical characteristics more similar to plutons of Cretaceous age in the coastal batholiths (Peninsular Ranges and Sierra Nevada) than to most Mesozoic plutons in the Cordilleran Interior. The studied plutons are calcic, in contrast to the mostly calc-alkaline Mesozoic plutons of the eastern Mojave Desert. Distinctive isotopic signatures of the granitoids include lower initial Sr-87/Sr-86 of 0.705-0.710, delta(18)O of + 6.3 to + 77 parts per thousand, Pb-208/Pb-204 of 38.3-39.5, and higher epsilon(Nd) of - 3.86 to - 9.60 than the Late Cretaceous plutons in the region. The distinctive characteristics of these Early Cretaceous plutons are probably both location and time specific and result from: (I) emplacement in a cold, untapped 'Mojave-type' Proterozoic upper crust, (2) a significant component of basaltic magmas partially melted from the asthenosphere or subcontinental lithosphere and (3) a magmatic component derived from Proterozoic, mafic, lower crust. They interacted less with their crustal hosts than did the later, more voluminous Late Cretaceous plutons. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. LA TROBE UNIV, SCH EARTH SCI, BUNDOORA, VIC 3083, AUSTRALIA. RP Allen, CM (reprint author), AUSTRALIAN NATL UNIV, DEPT GEOL, GPO BOX 4, CANBERRA, ACT 0200, AUSTRALIA. RI Foster, David/F-1727-2010; OI Foster, David/0000-0002-5603-9372 NR 87 TC 5 Z9 5 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0022-3530 J9 J PETROL JI J. Petrol. PD DEC PY 1995 VL 36 IS 6 BP 1675 EP 1700 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ778 UT WOS:A1995TQ77800009 ER PT J AU Wang, WX Fisher, NS Luoma, SN AF Wang, WX Fisher, NS Luoma, SN TI Assimilation of trace elements ingested by the mussel Mytilus edulis: Effects of algal food abundance SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE mussels; assimilation; bioindicators; metals; Americium; cadmium; cobalt; selenium; silver; zinc ID DEPOSIT FEEDERS; CADMIUM UPTAKE; MODEL; BIOKINETICS; ABSORPTION; DIGESTION; AMERICIUM; SELENIUM; BIVALVES; ZINC AB Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements (Ag-110, Am-241, Cd-109, Co-57, Se-75 and Zn-65) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h(-1)). Uniformly radio-labeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with inges tion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis. In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels. C1 SUNY STONY BROOK, MARINE SCI RES CTR, STONY BROOK, NY 11794 USA. US GEOL SURVEY, DIV WATER RESOURCES, MENLO PK, CA 94025 USA. RI Wang, Wen-Xiong/E-7254-2011; OI Wang, Wenxiong/0000-0001-9033-0158 NR 48 TC 107 Z9 109 U1 2 U2 18 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD DEC PY 1995 VL 129 IS 1-3 BP 165 EP 176 DI 10.3354/meps129165 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA TP664 UT WOS:A1995TP66400018 ER PT J AU Langer, MR Lipps, JH Ingle, JC Sliter, WV AF Langer, MR Lipps, JH Ingle, JC Sliter, WV TI FORAMS '94 - Selected papers from the Fifth International Symposium of Foraminifera, held July 5-9, 1994 at the Clark Kerr Campus of the University of California at Berkeley - Preface SO MARINE MICROPALEONTOLOGY LA English DT Editorial Material C1 STANFORD UNIV,DEPT GEOL,STANFORD,CA 94305. US GEOL SURVEY,MENLO PK,CA 94025. RP Langer, MR (reprint author), UNIV CALIF BERKELEY,MUSEUM PALEONTOL,BERKELEY,CA 94720, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD DEC PY 1995 VL 26 IS 1-4 BP 1 EP 2 DI 10.1016/0377-8398(95)90011-X PG 2 WC Paleontology SC Paleontology GA TQ757 UT WOS:A1995TQ75700001 ER PT J AU Starratt, SW AF Starratt, SW TI Latest Quaternary foraminifers and sediment transport in Pervenets Canyon, Bering Sea SO MARINE MICROPALEONTOLOGY LA English DT Article; Proceedings Paper CT 5th International Symposium on Foraminifera (FORAMS 94) CY JUL 04-05, 1994 CL UNIV CALIF BERKELEY, CLARK KERR CAMPUS, BERKELEY, CA SP US Geol Survey, Branch Paleontol & Stratig, Cushman Fdn Foraminiferal Res, Stanford Univ, Geol Dept, Museum Paleontol HO UNIV CALIF BERKELEY, CLARK KERR CAMPUS ID CONTINENTAL-SHELF; HOLOCENE FORAMINIFERA; NORWAY; CALIFORNIA; ALASKA; BASINS; TROMS; SLOPE AB A combination of microfossil and sediment analysis has been used in an attempt to understand oceanographic processes and the late Quaternary history of the Pervenets Canyon region. The primary sedimentation process in Pervenets Canyon is downslope transport. Near the shelfbreak, there is evidence of turbidite and debris-flow activity, but at the distal end of the upper canyon and on the continental slope there is no macroscopic evidence for these processes. Analysis of the foraminiferal assemblages shows that the fauna is 97.6% from the Suborder Rotaliina and about 2.0% from the Suborder Textulariina. The Suborder Miliolina accounts for approximately 0.4% of the fauna. The Pervenets Canyon fauna is most similar to other faunas from the Bering Sea, indicating a North Pacific Ocean influence on the fauna. Foraminiferal abundance and species diversity vary widely in the samples studied. The major factors controlling these values are downslope transport of sediment, disintegration of arenaceous taxa, dissolution of calcareous taxa, and diversity limited by low-oxygen bottom waters. Downslope transport of shelf species is indicated by the presence of Elphidium clavatum and E. excauatum. Shallow-shelf and low-oxygen foraminiferal faunas are often intermixed in the samples. The distribution of these low-oxygen faunas in Core 81-65 suggests that the oxygen-minimum zone fluctuated with sea level. RP Starratt, SW (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 959,MENLO PK,CA 94025, USA. NR 63 TC 1 Z9 1 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD DEC PY 1995 VL 26 IS 1-4 BP 233 EP 243 DI 10.1016/0377-8398(95)00041-0 PG 11 WC Paleontology SC Paleontology GA TQ757 UT WOS:A1995TQ75700023 ER PT J AU Evans, JR Kaminski, MA Cronin, TM Futterer, DK AF Evans, JR Kaminski, MA Cronin, TM Futterer, DK TI Pleistocene agglutinated foraminifera from the Lomonosov Ridge and Amundsen Basin, Arctic Basin. Initial report on piston cores 2177-5 (KAL) and 2176-3 (KAL) SO MARINE MICROPALEONTOLOGY LA English DT Article; Proceedings Paper CT 5th International Symposium on Foraminifera (FORAMS 94) CY JUL 04-05, 1994 CL UNIV CALIF BERKELEY, CLARK KERR CAMPUS, BERKELEY, CA SP US Geol Survey, Branch Paleontol & Stratig, Cushman Fdn Foraminiferal Res, Stanford Univ, Geol Dept, Museum Paleontol HO UNIV CALIF BERKELEY, CLARK KERR CAMPUS ID OCEAN AB Noncalcareous Pleistocene sediments of the Central Arctic Ocean contain sparse benthic foraminiferal assemblages consisting entirely of agglutinated taxa. Deep water agglutinated foraminifera are studied from two piston cores collected from the Lomonosov Ridge and Amundsen Basin [Cores PS 2177-5 (KAL) and 2176-3 (KAL)]. Core PS 2177-5 (KAL) contains an assemblage of 10 species, dominated by Cyclammina pusilla Brady, and is interpreted to reflect a bathyal environment with variable organic flux and nutrition levels. Core PS 2176-3 (KAL) in the Amundsen Basin yielded a very depauperate benthic foraminiferal assemblage, It is assumed that the environment was inhospitable for agglutinated foraminifera. C1 UNIV LONDON BIRKBECK COLL,RES SCH,LONDON WC1E 6BT,ENGLAND. US GEOL SURVEY,RESTON,VA 22092. ALFRED WEGENER INST POLAR & MARINE RES,D-27515 BREMERHAVEN,GERMANY. RP Evans, JR (reprint author), UNIV LONDON UNIV COLL,DEPT GEOL SCI,GOWER ST,LONDON WC1E 6BT,ENGLAND. RI Kaminski, Michael/K-3334-2012 NR 19 TC 5 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD DEC PY 1995 VL 26 IS 1-4 BP 245 EP 253 DI 10.1016/0377-8398(95)00016-X PG 9 WC Paleontology SC Paleontology GA TQ757 UT WOS:A1995TQ75700024 ER PT J AU Mullen, MW McNeil, DH AF Mullen, MW McNeil, DH TI Biostratigraphic and paleoclimatic significance of a new Pliocene foraminiferal fauna from the central Arctic Ocean SO MARINE MICROPALEONTOLOGY LA English DT Article; Proceedings Paper CT 5th International Symposium on Foraminifera (FORAMS 94) CY JUL 04-05, 1994 CL UNIV CALIF BERKELEY, CLARK KERR CAMPUS, BERKELEY, CA SP US Geol Survey, Branch Paleontol & Stratig, Cushman Fdn Foraminiferal Res, Stanford Univ, Geol Dept, Museum Paleontol HO UNIV CALIF BERKELEY, CLARK KERR CAMPUS ID NORTH-ATLANTIC; OLIGOCENE; SEA AB A Pliocene benthic foraminiferal fauna containing a previously unknown species association was found in the basal section of a piston core collected from the crest of Northwind Ridge (NWR) in the central Arctic Ocean. The fauna is dominated by Epistominella exigua, Cassidulina reniforme, Eponides tumidulus, Cibicides scaldisiensis, Lagena spp., Cassidulina teretis, Eponides weddellensis, Bolivina arctica, and Patellina corrugata. The presence of Cibicides scaldisiensis in the assemblage and the occurrence of Cibicides grossus higher in the core are indicative of an early Pliocene age. The morphologically distinctive species Cibicidoides sp. 795 of McNeil (in press) which occurs in the NWR core sample was previously known only from Oligocene through Miocene deposits in the Beaufort-Mackenzie Basin of Arctic Canada. Ehrenbergina sp. A and Cibicidoides aff. C. sp. 795, also present in the core, are new and endemic to the Arctic late Miocene and early Pliocene. These species, and possibly others, are survivors of the late Miocene (Messinian) sea-level crisis, which caused a significant faunal turnover in the Arctic Ocean. The predominantly calcareous assemblage indicates deposition above the calcium carbonate compensation depth in an upper bathyal environment. Paleogeographic affinities for the bulk of the assemblage indicate probable connections between the Arctic and the North Atlantic Oceans, but the endemic species identify environmental differences or partial isolation of the western Arctic Ocean. The species association suggests a cold but milder paleoclimate than that which existed during Pleistocene glacial intervals. C1 GEOL SURVEY CANADA,INST SEDIMENTARY & PETR GEOL,CALGARY,AB T2L 2A7,CANADA. RP Mullen, MW (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 22 TC 12 Z9 12 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD DEC PY 1995 VL 26 IS 1-4 BP 273 EP 280 DI 10.1016/0377-8398(96)87758-9 PG 8 WC Paleontology SC Paleontology GA TQ757 UT WOS:A1995TQ75700026 ER PT J AU STEINWAND, DR HUTCHINSON, JA SNYDER, JP AF STEINWAND, DR HUTCHINSON, JA SNYDER, JP TI MAP PROJECTIONS FOR GLOBAL AND CONTINENTAL DATA SETS AND AN ANALYSIS OF PIXEL DISTORTION CAUSED BY REPROJECTION SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB With growing emphasis on global monitoring research using remotely sensed data and geographic information systems is increasingly focused on large regions studied at small scales. These global change studies require the integration of data sets from several sources that are reprojected to a common map base. In small-area, large-scale studies the choice of a map projection has little effect on data quality. In global change studies the effects of map projection properties on data quality are more apparent, and the choice of projection is more significant To aid compilers of global and continental data sets, six equal-area projections were chosen: the interrupted Goode Homolosine, the interrupted Mollweide, the Wagner IV, and the Wagner VII for global maps; the Lambert Azimuthal Equal-Area for hemisphere maps; and the Oblated Equal-Area and the Lambert Azimuthal Equal-Area for continental maps. Distortions in small-scale maps caused by reprojection, and the additional distortions incurred when reprojecting roster images, were quantified and graphically depicted. For raster images, the errors caused by the usual resampling methods (pixel brightness level interpolation) were responsible for much of the additional error where the local resolution and scale change were the greatest. C1 US GEOL SURVEY,RESTON,VA 22092. RP STEINWAND, DR (reprint author), US GEOL SURVEY,EROS DATA CTR,HUGHES STX CORP,SIOUX FALLS,SD 57198, USA. NR 4 TC 30 Z9 31 U1 0 U2 4 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 1995 VL 61 IS 12 BP 1487 EP 1497 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA TH678 UT WOS:A1995TH67800006 ER PT J AU BATSON, RM ELIASON, EM AF BATSON, RM ELIASON, EM TI DIGITAL MAPS OF MARS SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID VIKING AB A cartographic digital model (DM) of Mars containing controlled image mosaics and topographic measurements has been prepared for distribution on CD-ROM optical disks. This database is the product of an exhaustive Mars cartography project based on data from the Viking Orbiter missions. It includes a radiometrically and geometrically controlled, photometrically modeled global image mosaic at a resolution of 1/256 degrees/pixel (231 m), a digital topographic model of the entire planet at a resolution of 1/64 degrees (about 1 km), a series of multispectral image mosaics, and selected high-resolution (greater than or equal to 7 m/pixel) image mosaics. This collection of 21 disks is expected to provide support not only for primary scientific investigations of Mars but also for the scientific and engineering operations of future expeditions to that planet. RP BATSON, RM (reprint author), US GEOL SURVEY,DIV GEOL,ASTROGEOL BRANCH,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 35 TC 11 Z9 11 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 1995 VL 61 IS 12 BP 1499 EP 1507 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA TH678 UT WOS:A1995TH67800007 ER PT J AU OKAL, EA KIRBY, SH AF OKAL, EA KIRBY, SH TI FREQUENCY-MOMENT DISTRIBUTION OF DEEP EARTHQUAKES - IMPLICATIONS FOR THE SEISMOGENIC ZONE AT THE BOTTOM OF SLABS SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article ID FOCUS EARTHQUAKES; SOURCE PARAMETERS; OCEANIC TRANSFORM; SCALING RELATIONS; RIDGE EARTHQUAKE; INTERMEDIATE; MECHANISM AB We present a systematic investigation of the variation with depth of the frequency of earthquake occurrence vs. seismic moment based on 16 years of Harvard Centroid Moment Tensor (CMT) solutions. We analyze depth variations of earthquake size distribution in terms of variations in the absolute value of the slope of the regression of the logarithm of the population vs. seismic moment, a quantity known as the beta parameter. The shallowest earthquakes (0-50 km depth) exhibit a well-defined and robust size distribution regime characterized by a discontinuous increase in beta with increasing moment. Others have shown that this increase probably represents the effects of a physical limit in the dimensions of the area of seismogenic slip of shallow earthquake sources. The population of deep earthquakes in the depth interval 500-600 km shows two markedly different distributions. The deep earthquakes in the Tonga region feature an initially high beta value (0.92) at small moments and a lower beta value (0.41) at high moments. In contrast, the size distribution of non-Tonga deep events shows the reverse of those changes (beta = 0.41 at low moment and beta = 1.17 at higher moment). To help explain these observations, we propose a model of deep seismogenesis that assumes three-dimensional earthquake source regions that vary principally in their transverse dimensions. The two-beta segment behavior in the Tonga region and other subduction zones is thought to represent, in part, constraints owing to the threshold of completeness of the CMT catalog and to its short time interval of sampling. We interpret the differences between Tonga and other deep Wadati-Benioff zones as being a consequence of Tonga's markedly higher subduction rate and, hence, its colder thermal structure and presumably thicker region of seismogenesis. We interpret the critical moments at which beta values change in terms of variations in the transverse thickness of deep seismogenic zones and estimate that it is about 11 km for the Tonga region and about 3 km for other zones at depths of 500-600 km. These results are generally consistent with deep earthquakes being restricted to wedge-shaped regions of peridotite persisting metastably to as deep as 700 km in old, rapidly descending and hence cold slabs. Failure is thought to occur in metastable peridotite by transformational faulting. Great deep earthquakes present special challenges to any theory of deep earthquakes based on slab thermal structure. For example, a continuing question is how such large events can fit in a thermally controlled seismogenic zone that is diminishing in its transverse dimensions with increasing depth. The very concept of a scale-invariant earthquake size distribution may be inappropriate for these rare events and the unusual settings in which they are found. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP OKAL, EA (reprint author), NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60208, USA. NR 54 TC 27 Z9 27 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD DEC PY 1995 VL 92 IS 3-4 BP 169 EP 187 DI 10.1016/0031-9201(95)03037-8 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TG818 UT WOS:A1995TG81800003 ER PT J AU Cai, YG Wang, CY Hwang, WT Cochrane, GR AF Cai, YG Wang, CY Hwang, WT Cochrane, GR TI The effect of fault-bend folding on seismic velocity in the marginal ridge of accretionary prisms SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT IUTAM/IASPEI Symposium on Mechanics Problems in Geodynamics CY SEP 05-09, 1994 CL BEIJING, PEOPLES R CHINA SP IUTAM, IASPEI DE fault-bend folding; seismic velocity; accretionary prisms ID FLUID-FLOW; SUBDUCTION ZONE; OREGON; COMPLEX; DEFORMATION; WEDGES; WASHINGTON; SEDIMENTS; PRESSURE AB Fluid venting in accretionary prisms, which feeds chemosynthetic biological communities, occurs mostly on the marginal thrust ridge. New seismic data for the marginal ridge of the Cascadia prism show significantly lower velocity than that in the adjacent oceanic basin and place important constraints on the interpretations of why fluid venting occurs mostly on the marginal ridge. We employed a finite-element method to analyze a typical fault-bend folding model to explain the phenomenon. The fault in the model is simulated by contact elements. The elements are characterized not only by finite sliding along a slide line, but also by elastoplastic deformation. We present the results of a stress analysis which show that the marginal ridge is under subhorizontal extension and the frontal thrust is under compression. This state of stress favors the growth of tensile cracks in the marginal ridge, facilitates fluid flow and reduces seismic velocities therein; on the other hand, it may close fluid pathways along the frontal thrust and divert fluid how to the marginal ridge. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Cai, YG (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. NR 34 TC 3 Z9 4 U1 0 U2 2 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 1995 VL 145 IS 3-4 BP 637 EP 646 DI 10.1007/BF00879593 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TT006 UT WOS:A1995TT00600014 ER PT J AU Lockner, DA Byerlee, JD AF Lockner, DA Byerlee, JD TI An earthquake instability model based on faults containing high fluid-pressure compartments SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT IUTAM/IASPEI Symposium on Mechanics Problems in Geodynamics CY SEP 05-09, 1994 CL BEIJING, PEOPLES R CHINA SP IUTAM, IASPEI DE earthquake cycle; overpressure; fluid compartments; dynamic earthquake model ID TIME-DEPENDENT FRICTION; PORE FLUID; SIMULATED FAULT; STICK-SLIP; HEAT-FLOW; GOUGE; ZONE; AFTERSHOCKS; COMPACTION; MECHANICS AB It has been proposed that large strike-slip faults such as the San Andreas contain water in seal-bounded compartments. Arguments based on heat flow and stress orientation suggest that in most of the compartments, the water pressure is so high that the average shear strength of the fault is less than 20 MPa. We propose a variation of this basic model in which most of the shear stress on the fault is supported by a small number of compartments where the pore pressure is relatively low. As a result, the fault gouge in these compartments is compacted and lithified and has a high undisturbed strength. When one of these locked regions fails, the system made up of the neighboring high and low pressure compartments can become unstable. Material in the high fluid pressure compartments is initially underconsolidated since the low effective confining pressure has retarded compaction. As these compartments are deformed, fluid pressure remains nearly unchanged so that they offer little resistance to shear. The low pore pressure compartments, however, are overconsoiidated and dilate as they are sheared. Decompression of the pore fluid in these compartments lowers fluid pressure, increasing effective normal stress and shear strength. While this effect tends to stabilize the fault, it can be shown that this dilatancy hardening can be more than offset by displacement weakening of the fault (i.e., the drop from peak to residual strength). If the surrounding rock mass is sufficiently compliant to produce an instability, slip will propagate along the fault until the shear fracture runs into a low-stress region. Frictional heating and the accompanying increase in fluid pressure that are suggested to occur during shearing of the fault zone will act as additional destabilizers. However, significant heating occurs only after a finite amount of slip and therefore is more likely to contribute to the energetics of rupture propagation than to the initiation of the instability. We present results of a one-dimensional dynamic Burridge-Knopoff-type model to demonstrate various aspects of the fluid-assisted fault instability described above. In the numerical model, the fault is represented by a series of blocks and springs, with fault rheology expressed by static and dynamic friction. In addition, the fault surface of each block has associated with it pore pressure, porosity and permeability. All of these variables are allowed to evolve with time, resulting in a wide range of phenomena related to fluid diffusion, dilatancy, compaction and heating. These phenomena include creep events, diffusion-controlled precursors, triggered earthquakes, foreshocks, aftershocks, and multiple earthquakes. While the simulations have limitations inherent to I-D fault models, they demonstrate that the fluid compartment model can, in principle, provide the rich assortment of phenomena that have been associated with earthquakes. RP Lockner, DA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 45 TC 27 Z9 28 U1 1 U2 4 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 1995 VL 145 IS 3-4 BP 717 EP 745 DI 10.1007/BF00879597 PG 29 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TT006 UT WOS:A1995TT00600018 ER PT J AU SKOG, JE LITWIN, RJ AF SKOG, JE LITWIN, RJ TI REEXAMINATION OF THE FOSSIL FERN GENUS DRYOPTERITES BERRY BASED ON REPRODUCTIVE CHARACTERISTICS SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Article ID SPORES; MATONIACEAE; INSITU AB The specimens assigned to the genus Dryopterites Berry were reexamined and details of the reproductive characters including the spores are described for the first time. Based upon this new information about the ferns, two species have remained in the genus Dryopterites with one designated as the type species (D. virginica) and a lectotype for this species is chosen; one species (D. dentata) has previously been reassigned to the family Schizaeaceae, and the remaining species (D. macrocarpa, D. elliptica, D. cystopteroides) have been assigned to the genus Delosorus in the family Matoniaceae. This new information and comparisons with Sporae Dispersae suggest a later Cretaceous occurrence of ferns related to the modern dryopterids. C1 US GEOL SURVEY,RESTON,VA 22092. RP SKOG, JE (reprint author), GEORGE MASON UNIV,DEPT BIOL,FAIRFAX,VA 22030, USA. NR 16 TC 4 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0034-6667 J9 REV PALAEOBOT PALYNO JI Rev. Palaeobot. Palynology PD DEC PY 1995 VL 89 IS 3-4 BP 235 EP 256 DI 10.1016/0034-6667(95)00002-9 PG 22 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA TK117 UT WOS:A1995TK11700004 ER PT J AU Saltus, RW Thompson, GA AF Saltus, RW Thompson, GA TI Why is it downhill from Tonopah to Las Vegas? A case for mantle plume support of the high northern Basin and Range SO TECTONICS LA English DT Article ID WESTERN UNITED-STATES; SOUTHERN GREAT-BASIN; CONTINENTAL LITHOSPHERE; NORTHWESTERN BASIN; CRUSTAL STRUCTURE; ISOTOPIC EVIDENCE; NEVADA; PROVINCE; MAGMATISM; MODEL AB A major, abrupt, southward decline in elevation (similar to 800 m) with an accompanying increase in Bouguer gravity anomaly (similar to 80 mGal) crosses a seismically active region of southern Nevada at about 37 degrees N. The steepness of the gravity gradient requires significant crustal density contrast, some of which is probably caused by the plutonic roots of voluminous Tertiary volcanism to the north, but the amplitude of the anomaly requires additional contrast within the mantle. The topographic step probably developed in mid-Miocene time, coincident with the arrival of the starting head of the Yellowstone thermal plume at the base of the lithosphere. A plausible combination of crustal and deep buoyancy sources, related to the heat and melt input of an anomalously hot asthenospheric source, is consistent with gravity, seismic, heat flow, and isotopic observations and explains the origin of the topographic step. C1 STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305. RP Saltus, RW (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 964,BOX 25046,DENVER,CO 80225, USA. NR 54 TC 37 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD DEC PY 1995 VL 14 IS 6 BP 1235 EP 1244 DI 10.1029/95TC02288 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TN077 UT WOS:A1995TN07700001 ER PT J AU Holland, D Simmons, C Smith, L Cohn, T Baier, G Lynch, J Grimm, J Oehlert, G Lindberg, S AF Holland, D Simmons, C Smith, L Cohn, T Baier, G Lynch, J Grimm, J Oehlert, G Lindberg, S TI Long-term trends in NADP/NTN precipitation chemistry data: Results of different statistical analyses SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT 5th International Conference on Acidic Deposition - Science and Policy: Acid Reign 95 CY JUN 26-30, 1995 CL GOTHENBURG, SWEDEN SP Swedish Environm Protect Agcy, Swedish Environm Res Inst, Provincial Govt Goteborg, Provincial Govt Bohus Ian DE long-term trends; sulfate; statistical models ID SULFATE AB This paper summarizes the results of four statistical approaches for the estimation of long-term trends (1983-92) in sulfate concentration data from 90 monitoring sites across the United States. Least squares regression models and nonparametric techniques were applied to these data. Sulfate concentrations were found to be generally decreasing on the order of 0-4% at most sites. There was general agreement that trends were significant in the Great Lakes, Pacific northwest, and southwest regions. Although strengths and weaknesses are described for each approach, all of these approaches are useful for long-term trend estimation. Visualization techniques are recommended for displaying trend patterns and associated levels of statistical significance. C1 COLORADO STATE UNIV,FT COLLINS,CO 80523. MANTECH ENVIRONM TECHNOL INC,RES TRIANGLE PK,NC 27709. US GEOL SURVEY,RESTON,VA 22092. PENN STATE UNIV,UNIVERSITY PK,PA 16802. UNIV MINNESOTA,ST PAUL,MN 55108. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Holland, D (reprint author), US EPA,RES TRIANGLE PK,NC 27711, USA. NR 10 TC 10 Z9 10 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD DEC PY 1995 VL 85 IS 2 BP 595 EP 601 DI 10.1007/BF00476894 PG 7 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA UB053 UT WOS:A1995UB05300052 ER PT J AU Spiker, EC Hosker, RP Weintraub, VC Sherwood, SI AF Spiker, EC Hosker, RP Weintraub, VC Sherwood, SI TI Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT 5th International Conference on Acidic Deposition - Science and Policy: Acid Reign 95 CY JUN 26-30, 1995 CL GOTHENBURG, SWEDEN SP Swedish Environm Protect Agcy, Swedish Environm Res Inst, Provincial Govt Goteborg, Provincial Govt Bohus Ian DE dry deposition; sulfur dioxide; chamber; wind tunnel; corrosion; limestone; marble; humidity; moisture ID WET DEPOSITION; STONE AB The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffeting capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O-3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet. C1 US OCEAN & ATMOSPHER ADM,OAK RIDGE,TN 37831. NATL PK SERV,WASHINGTON,DC 20013. RP Spiker, EC (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 18 TC 15 Z9 15 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD DEC PY 1995 VL 85 IS 4 BP 2679 EP 2685 DI 10.1007/BF01186239 PG 7 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA UE158 UT WOS:A1995UE15800135 ER PT J AU Hsieh, PA Cooley, RL AF Hsieh, PA Cooley, RL TI Horizontal aquifer movement in a Theis-Theim confined system - Comment SO WATER RESOURCES RESEARCH LA English DT Article C1 US GEOL SURVEY,DIV WATER RESOURCES,FED CTR,LAKEWOOD,CO 80225. RP Hsieh, PA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,345 MIDDLEFIELD RD,MS 496,MENLO PK,CA 94025, USA. NR 11 TC 4 Z9 4 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1995 VL 31 IS 12 BP 3107 EP 3111 DI 10.1029/95WR02713 PG 5 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TK647 UT WOS:A1995TK64700019 ER PT J AU Wood, WW Sanford, WE AF Wood, WW Sanford, WE TI Eolian transport, saline lake basins, and groundwater solutes SO WATER RESOURCES RESEARCH LA English DT Article ID DEPOSITION AB Eolian processes associated with saline lakes are shown to be important in determining solute concentration in groundwater in arid and semiarid areas. Steady state mass balance analyses of chloride in the groundwater at Double Lakes, a saline lake basin in the southern High Plains of Texas, United States, suggest that approximately 4.5 x 10(5) kg of chloride is removed from the relatively small (4.7 km(2)) basin floor each year by deflation. This mass enters the groundwater down the wind gradient from the lake, degrading the water quality. The estimates of mass transport were independently determined by evaluation of solutes in the unsaturated zone and by solute mass balance calculations of groundwater flux. Transport of salts from the lake was confirmed over a short term (2 years) by strategically placed dust collectors. Results consistent with those at Double Lake were obtained from dune surfaces collected upwind and downwind from a sabkha near the city of Abu Dhabi in the United Arab Emirates. The eolian transport process provides an explanation of the degraded groundwater quality associated with the 30-40 saline lake basins on the southern half of the southern High Plains of Texas and New Mexico and in many other arid and semiarid areas. RP Wood, WW (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 431,RESTON,VA 22092, USA. NR 31 TC 42 Z9 43 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1995 VL 31 IS 12 BP 3121 EP 3129 DI 10.1029/95WR02572 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TK647 UT WOS:A1995TK64700022 ER PT J AU Connell, TL Dreiss, SJ AF Connell, TL Dreiss, SJ TI Chemical evolution of shallow groundwater along the northeast shore of Mono Lake, California SO WATER RESOURCES RESEARCH LA English DT Article ID GREAT SALT LAKE; CLOSED-BASIN; GEOCHEMISTRY; WATER; UTAH; USA AB We attempted to quantitatively discriminate between hypothesized sources and geochemical processes responsible for the chemical evolution of shallow groundwater along the northeast shore of Mono Lake, an alkaline saline lake located in a hydrologically closed basin in east central California. Shallow groundwater samples from 17 sites perpendicular and 11 sites parallel to the lakeshore were analyzed for major ions. The shallow groundwater contains remnant solutes from higher lake stands, which are transported toward the lake by lateral flow and surface runoff. The flow system appears to be segregated into two different regions: a concentrated, highly saline groundwater underlying much of the northeast shore and pockets of more localized lower-salinity groundwater. The saturation stare of the groundwater with respect to certain minerals was determined, and simulations for both evaporative concentration of inflow and mixing of lake water with inflow coupled with mineral precipitation were performed. Solute trends in the shallow groundwater result primarily from the degree of mixing with historical lake water; however, evaporative concentration and redissolution cycles along with various chemical fractionation mechanisms including Ca, Mg, and Na carbonate precipitation, sulfate reduction, ion exchange, and potentially Mg silicate formation are also important controls. C1 UNIV CALIF SANTA CRUZ,DEPT EARTH SCI,SANTA CRUZ,CA 95064. RP Connell, TL (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 465,MENLO PK,CA 94025, USA. NR 44 TC 8 Z9 8 U1 3 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1995 VL 31 IS 12 BP 3171 EP 3182 DI 10.1029/95WR02566 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TK647 UT WOS:A1995TK64700025 ER PT J AU Essaid, HI Bekins, BA Godsy, EM Warren, E Baedecker, MJ Cozzarelli, IM AF Essaid, HI Bekins, BA Godsy, EM Warren, E Baedecker, MJ Cozzarelli, IM TI Simulation of aerobic and anaerobic biodegradation processes at a crude oil spill site SO WATER RESOURCES RESEARCH LA English DT Article ID COMPOSITIONAL MULTIPHASE MODEL; BIOLOGICALLY REACTING SOLUTES; OXYGEN-LIMITED BIODEGRADATION; EVALUATING PAH DEGRADATION; SANDY AQUIFER MATERIAL; POLLUTION PLUME VEJEN; SHALLOW SAND; GRAVEL AQUIFER; POROUS-MEDIA; GROUND-WATER AB A two-dimensional, multispecies reactive solute transport model with sequential aerobic and anaerobic degradation processes was developed and tested. The model was used to study the field-scale solute transport and degradation processes at the Bemidji, Minnesota, crude oil spill site. The simulations included the biodegradation of volatile and nonvolatile fractions of dissolved organic carbon by aerobic processes, manganese and iron reduction, and methanogenesis. Model parameter estimates were constrained by published Monod kinetic parameters, theoretical yield estimates, and field biomass measurements. Despite the considerable uncertainty in the model parameter estimates, results of simulations reproduced the general features of the observed groundwater plume and the measured bacterial concentrations. In the simulation, 46% of the total dissolved organic carbon (TDOC) introduced into the aquifer was degraded. Aerobic degradation accounted for 40% of the TDOC degraded. Anaerobic processes accounted for the remaining 60% of degradation of TDOC: 5% by Mn reduction, 19% by Fe reduction, and 36% by methanogenesis. Thus anaerobic processes account for more than half of the removal of DOC at this site. C1 US GEOL SURVEY, RESTON, VA 22092 USA. RP Essaid, HI (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. OI Cozzarelli, Isabelle/0000-0002-5123-1007 NR 84 TC 131 Z9 135 U1 3 U2 34 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1995 VL 31 IS 12 BP 3309 EP 3327 DI 10.1029/95WR02567 PG 19 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TK647 UT WOS:A1995TK64700036 ER PT J AU Angus, S AF Angus, S TI Women in natural resources: Stimulating thinking about motivations and needs SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE gender; motivation; professional opportunity; women RP Angus, S (reprint author), US FISH & WILDLIFE SERV,MANAGEMENT ASSISTANCE TEAM,1201 OAK RIDGE DR,SUITE 300,FT COLLINS,CO 80525, USA. NR 0 TC 7 Z9 7 U1 0 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD WIN PY 1995 VL 23 IS 4 BP 579 EP 582 PG 4 WC Biodiversity Conservation SC Biodiversity & Conservation GA TW251 UT WOS:A1995TW25100008 ER PT J AU Broyles, B AF Broyles, B TI Desert wildlife water developments: Questioning use in the Southwest SO WILDLIFE SOCIETY BULLETIN LA English DT Review DE critique; desert bighorn sheep; Ovis canadensis mexicana; Sonoran Desert; water development; wildlife ID BIGHORN SHEEP; ARIZONA C1 US FISH & WILDLIFE SERV, WASHINGTON, DC USA. NR 139 TC 53 Z9 56 U1 0 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1938-5463 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD WIN PY 1995 VL 23 IS 4 BP 663 EP 675 PG 13 WC Biodiversity Conservation SC Biodiversity & Conservation GA TW251 UT WOS:A1995TW25100022 ER PT J AU Saltz, D White, GC Bartmann, RM DelGiudice, G Riggs, MR Mech, LD Seal, US AF Saltz, D White, GC Bartmann, RM DelGiudice, G Riggs, MR Mech, LD Seal, US TI Assessing animal condition, nutrition, and stress from urine in snow - A critical view SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE condition; cortisol; creatine; nutrition; nutritional condition; urea nitrogen; urine in snow ID WHITE-TAILED DEER; DENSITY INDEX ASSUMPTION; UREA NITROGEN RESPONSES; MULE DEER; GRAY PARTRIDGE; SEASONAL INFLUENCES; BODY-COMPOSITION; WINTER; CORTISOL; PROTEIN C1 COLORADO STATE UNIV,DEPT FISHERY & WILDLIFE BIOL,FT COLLINS,CO 80523. COLORADO DIV WILDLIFE,RES SECT,FT COLLINS,CO 80526. MINNESOTA DEPT NAT RESOURCES,FOREST WILDLIFE POPULAT & RES GRP,GRAND RAPIDS,MN 55744. MINNESOTA DEPT NAT RESOURCES,SECT WILDLIFE,ST PAUL,MN 55155. US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. WORLD CONSERVAT UNION,CAPT BREEDING SPECIALIST GRP,APPLE VALLEY,MN 55124. RP Saltz, D (reprint author), NATL RESERVES AUTHOR,DIV SCI,78 YIMEYAHU ST,IL-94467 JERUSALEM,ISRAEL. RI SALTZ, DAVID/F-1581-2012 NR 58 TC 23 Z9 24 U1 0 U2 10 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD WIN PY 1995 VL 23 IS 4 BP 694 EP 704 PG 11 WC Biodiversity Conservation SC Biodiversity & Conservation GA TW251 UT WOS:A1995TW25100026 ER PT J AU Loesch, CR Twedt, DJ Reinecke, KJ AF Loesch, CR Twedt, DJ Reinecke, KJ TI Conservation partnerships in the lower Mississippi Alluvial Valley SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE birds; conservation; Mississippi Valley; neotropical migrant; partnership; waterfowl C1 NATL BIOL SERV, SO SCI CTR, VICKSBURG, MS 39180 USA. RP Loesch, CR (reprint author), US FISH & WILDLIFE SERV, E CAPITOL AVE, BISMARCK, ND 58501 USA. OI Twedt, Daniel/0000-0003-1223-5045 NR 10 TC 8 Z9 8 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD WIN PY 1995 VL 23 IS 4 BP 791 EP 795 PG 5 WC Biodiversity Conservation SC Biodiversity & Conservation GA TW251 UT WOS:A1995TW25100041 ER PT J AU STEIN, RS AF STEIN, RS TI EARTHQUAKES - CHARACTERISTIC OR HAPHAZARD SO NATURE LA English DT Editorial Material ID RECURRENCE RP STEIN, RS (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 30 PY 1995 VL 378 IS 6556 BP 443 EP 444 DI 10.1038/378443a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TH054 UT WOS:A1995TH05400038 ER PT J AU STROM, RG SCHABER, GG DAWSON, DD KIRK, RL AF STROM, RG SCHABER, GG DAWSON, DD KIRK, RL TI THE GLOBAL RESURFACING OF VENUS - REPLY SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Note C1 US GEOL SURVEY,ASTROGEOL BRANCH,FLAGSTAFF,AZ 86001. RP STROM, RG (reprint author), UNIV ARIZONA,DEPT PLANETARY SCI,TUCSON,AZ 85721, USA. NR 14 TC 6 Z9 6 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 25 PY 1995 VL 100 IS E11 BP 23361 EP 23365 DI 10.1029/95JE02294 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH091 UT WOS:A1995TH09100010 ER PT J AU DWYER, GS CRONIN, TM BAKER, PA RAYMO, ME BUZAS, JS CORREGE, T AF DWYER, GS CRONIN, TM BAKER, PA RAYMO, ME BUZAS, JS CORREGE, T TI NORTH-ATLANTIC DEEP-WATER TEMPERATURE-CHANGE DURING LATE PLIOCENE AND LATE QUATERNARY CLIMATIC CYCLES SO SCIENCE LA English DT Article ID DEEP-OCEAN CIRCULATION; EUSTATIC SEA-LEVEL; OSTRACODES; RATES; WATER; MODE AB Variations in the ratio of magnesium to calcium (Mg/Ca) in fossil ostracodes from Deep Sea Drilling Project Site 607 in the deep North Atlantic show that the change in bottom water temperature during late Pliocene 41,000-year obliquity cycles averaged 1,5 degrees C between 3.2 and 2.8 million years ago (Ma) and increased to 2.3 degrees C between 2.8 and 2.3 Ma, coincidentally with the intensification of Northern Hemisphere glaciation. During the last two 100,000-year glacial-to-interglacial climatic cycles of the Quaternary, bottom water temperatures changed by 4.5 degrees C. These results show that glacial deepwater cooling has intensified since 3.2 Ma, most likely as the result of progressively diminished deepwater production in the North Atlantic and of the greater influence of Antarctic bottom water in the North Atlantic during glacial periods. The ostracode Mg/Ca data also allow the direct determination of the temperature component of the benthic foraminiferal oxygen isotope record from Site 607, as well as derivation of a hypothetical sea-level curve for the late Pliocene and late Quaternary. The effects of dissolution on the Mg/Ca ratios of ostracode shells appear to have been minimal. C1 US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,RESTON,VA 22092. MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. UNIV VERMONT,DEPT MATH & STAT,BURLINGTON,VT 05051. UNIV BORDEAUX 1,DEPT GEOL & OCEANOG,BORDEAUX,FRANCE. RP DWYER, GS (reprint author), DUKE UNIV,DEPT GEOL,DURHAM,NC 27708, USA. NR 50 TC 144 Z9 147 U1 0 U2 24 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 24 PY 1995 VL 270 IS 5240 BP 1347 EP 1351 DI 10.1126/science.270.5240.1347 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TF899 UT WOS:A1995TF89900035 ER PT J AU PRICE, LC SCHOELL, M AF PRICE, LC SCHOELL, M TI CONSTRAINTS ON THE ORIGINS OF HYDROCARBON-GAS FROM COMPOSITIONS OF GASES AT THEIR SITE OF ORIGIN SO NATURE LA English DT Article ID NATURAL GASES; KEROGEN AB It is widely accepted that natural gas is formed from thermal decomposition of both oil in reservoirs and, to a lesser extent, the organic matter in shales from which the oil was derived(1-6). But laboratory pyrolysis experiments on shales do not reproduce the methane-rich composition typical of most gas reservoirs(7), leading to suggestions(7) that other mechanisms, such as transition-metal catalysis, may be important. The discrepancy might, however, instead arise because gas (and oil) deposits have migrated from their source rocks, so that the reservoir composition might not be representative of the composition in the source rocks where the hydrocarbons were generated. To address this question, we have analysed gas samples coproduced with oils directly from a source rock (the Bakken shales, North Dakota, USA) where the local geology has prevented significant hydrocarbon migration. The methane contents of these Bakken-shale gases are much lower than that of conventional gas reservoirs, but are consistent with that from pyrolysis experiments(8,9) on these shales. Thus, because these Bakken gases form with (rather than from) oils, we argue that compositional differences between gases from source rocks and conventional gas deposits result from fractionation processes occurring after hydrocarbon expulsion from the source rock. C1 CHEVRON PETR TECHNOL CO,LA HABRA,CA 90633. RP PRICE, LC (reprint author), US GEOL SURVEY,DENVER FED CTR,MS-940,DENVER,CO 80225, USA. NR 20 TC 62 Z9 72 U1 2 U2 27 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 23 PY 1995 VL 378 IS 6555 BP 368 EP 371 DI 10.1038/378368a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TF893 UT WOS:A1995TF89300052 PM 11536709 ER PT J AU NELSON, AR ATWATER, BF BOBROWSKY, PT BRADLEY, LA CLAGUE, JJ CARVER, GA DARIENZO, ME GRANT, WC KRUEGER, HW SPARKS, R STAFFORD, TW STUIVER, M AF NELSON, AR ATWATER, BF BOBROWSKY, PT BRADLEY, LA CLAGUE, JJ CARVER, GA DARIENZO, ME GRANT, WC KRUEGER, HW SPARKS, R STAFFORD, TW STUIVER, M TI RADIOCARBON EVIDENCE FOR EXTENSIVE PLATE-BOUNDARY RUPTURE ABOUT 300 YEARS AGO AT THE CASCADIA SUBDUCTION ZONE SO NATURE LA English DT Article ID TIME SCALE; CALIBRATION; EARTHQUAKE; TECTONICS; BC AB THE Cascadia subduction zone, a region of converging tectonic plates along the Pacific coast of North America, has a geological history of very large plate-boundary earthquakes(1,2), but no such earthquakes have struck this region since Euro-American settlement about 150 years ago. Geophysical estimates of the moment magnitudes (M(w)) of the largest such earthquakes range from 8 (ref. 3) to 9 1/2 (ref. 4). Radiocarbon dating of earthquake-killed vegetation can set upper bounds on earthquake size by constraining the length of plate boundary that ruptured in individual earthquakes. Such dating has shown that the most recent rupture, or series of ruptures, extended at least 55 km along the Washington coast within a period of a few decades about 300 years ago(5). Here we report 85 new C-14 ages, which suggest that this most recent rupture (or series) extended at least 900 km between southern British Columbia and northern California. By comparing the C-14 ages with written records of the past 150 years, we conclude that a single magnitude 9 earthquake, or a series of lesser earthquakes, ruptured most of the length of the Cascadia subduction zone between the late 1600s and early 1800s, and probably in the early 1700s. C1 UNION COLL,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. UNIV WASHINGTON,DEPT GEOL SCI,US GEOL SURVEY,SEATTLE,WA 98195. BRITISH COLUMBIA GEOL SURVEY BRANCH,VICTORIA,BC V8V 1X4,CANADA. GEOL SURVEY CANADA,VANCOUVER,BC V6B 1R8,CANADA. HUMBOLDT STATE UNIV,DEPT GEOL,ARCATA,CA 95521. PORTLAND STATE UNIV,DEPT GEOL,PORTLAND,OR 97207. KRUEGER ENTERPRISES INC,DIV GEOCHRON LABS,CAMBRIDGE,MA 02138. INST GEOL & NUCL SCI LTD,RAFTER RADIOCARBON LAB,NUCL SCI GRP,LOWER HUTT,NEW ZEALAND. UNIV WASHINGTON,QUATERNARY RES CTR,SEATTLE,WA 98195. RP NELSON, AR (reprint author), US GEOL SURVEY,MS 966,BOX 25046,DENVER,CO 80225, USA. NR 32 TC 94 Z9 95 U1 1 U2 12 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 23 PY 1995 VL 378 IS 6555 BP 371 EP 374 DI 10.1038/378371a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TF893 UT WOS:A1995TF89300053 ER PT J AU MARONE, C VIDALE, JE ELLSWORTH, WL AF MARONE, C VIDALE, JE ELLSWORTH, WL TI FAULT HEALING INFERRED FROM TIME-DEPENDENT VARIATIONS IN-SOURCE PROPERTIES OF REPEATING EARTHQUAKES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FRICTION AB We analyze two sets of repeating earthquakes on the Calaveras fault to estimate in-situ rates of fault strengthening (healing). Earthquake recurrence intervals t(r) range from 3 to 803 days. Variations in relative moment and duration are combined to study changes in stress drop, rupture dimension, rupture velocity, and particle velocity as a function of t(r). Healing rates and source variations are compared with predictions of laboratory-derived friction laws. Two interpretations of event duration tau are used: one in which tau is given by the ratio of slip to particle velocity and one in which it scales as rupture dimension divided by rupture velocity. Our data indicate that faults strengthen during the interseismic period. We infer that source dimension decreases with t(r) due to aseismic creep within the region surrounding the repeating events. Stress drop increases 1-3MPa per decade increase in t(r), which represents an increase of a factor of 2-3 relative to events with t(r) between 10 and 100 days. This rate of fault healing is consistent with extrapolations of laboratory measurements of healing rates if fault strength is high, on order of 60MPa, and stress drop is roughly 10% of this value. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP MARONE, C (reprint author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 15 TC 104 Z9 109 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 15 PY 1995 VL 22 IS 22 BP 3095 EP 3098 DI 10.1029/95GL03076 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TF972 UT WOS:A1995TF97200022 ER PT J AU COLE, RB STANLEY, RG AF COLE, RB STANLEY, RG TI MIDDLE TERTIARY EXTENSION RECORDED BY LACUSTRINE FAN-DELTA DEPOSITS, PLUSH RANCH BASIN, WESTERN TRANSVERSE RANGES, CALIFORNIA SO JOURNAL OF SEDIMENTARY RESEARCH SECTION B-STRATIGRAPHY AND GLOBAL STUDIES LA English DT Article ID SAN-ANDREAS FAULT; ALLUVIAL-FAN; SOUTHERN-CALIFORNIA; DEBRIS-FLOW; TURBIDITY CURRENTS; JOAQUIN BASIN; BRAIDED-RIVER; SEDIMENTATION; EVOLUTION; SYSTEM AB The Plush Ranch Formation (upper Oligocene and lower Miocene) consists of more than 1800 m of nonmarine sedimentary and volcanic rocks that record the history of an extensional basin referred to here as the Plush Ranch basin, Distinctive depositional facies, provenance, and sediment transport directions along each basin margin suggest an asymmetric basin shape that is consistent with a half-graben origin. The northern basin margin consists of sandstone-dominated al luvial-plain deposits (0.1-1.5 m thick, normally graded, lenticular sandstone beds), Small deltaic sequences 1-2 m thick were formed where these alluvial systems flowed southward into a lake, Lenses of massive, boulder-rich granitic breccia that represent rockslide deposits derived from a nearby northern granitic provenance interfinger with the alluvial-plain facies, In contrast to the northern margin, the southern basin margin is represented by coarse grained fan-delta deposits, Matrix- and clast-supported lenticular conglomerate beds 0.2-5 m thick with interbedded trough-cross-bedded pebbly sandstone represent braided-stream and flood flow and/or noncohesive debris-flow deposits of alluvial fans that drained a highland area to the south. The alluvial fan deposits interfinger to the north with several types of subaqueous sediment-gravity flow facies including turbidite sandstone beds and matrix supported debris-flow conglomerate. Each of the basin-margin depositional systems grades basinward and to the east into lacustrine deposits that include organic rich dark shale, evaporite, and limestone, The lacustrine deposits represent the central and eastern parts of the Plush Ranch basin, which received little coarse siliciclastic sediment, Basalt deposits that are at least 50 m thick in the west and thicken eastward are interbedded mainly with the lacustrine facies. The southern margin of the Plush Ranch basin formed along a north dipping, normal-slip fault along which dip separation increased toward the southwest; the northern margin developed on the tilted hanging wall block of this fault, This fault was later reactivated in post-middle Miocene time as the present left lateral strike slip Big Pine fault, The Plush Ranch is one of several extensional and transtensional basins that formed in southern California and western Arizona about 25-20 Ma as a response to the change from a convergent to a strike-slip tectonic regime along western North America. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP COLE, RB (reprint author), ALLEGHENY COLL,DEPT GEOL,MEADVILLE,PA 16335, USA. NR 84 TC 11 Z9 13 U1 0 U2 2 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 1073-1318 J9 J SEDIMENT RES B JI J. Sediment. Res.-Sect. B-Stratigr. Glob. Stud. PD NOV 15 PY 1995 VL 65 IS 4 BP 455 EP 468 PG 14 WC Geology SC Geology GA TH904 UT WOS:A1995TH90400004 ER PT J AU TRINCARDI, F CORREGGIARI, A FIELD, ME NORMARK, WR AF TRINCARDI, F CORREGGIARI, A FIELD, ME NORMARK, WR TI TURBIDITE DEPOSITION FROM MULTIPLE SOURCES - QUATERNARY PAOLA BASIN (EASTERN TYRRHENIAN SEA) SO JOURNAL OF SEDIMENTARY RESEARCH SECTION B-STRATIGRAPHY AND GLOBAL STUDIES LA English DT Article ID CONTINENTAL-SHELF; MEDITERRANEAN-SEA; MARGIN; FAN; SEQUENCES; SEDIMENTATION; PATTERNS; ISOTOPE; SYSTEMS; CYCLES AB The western margin of the Calabrian Are is underlain by a thick (as much as 5 km) post-Miocene sedimentary succession, The uppermost part of this margin sequence is referred to as the Paola Basin System (Quaternary in age) and partially fills a present-day physiographic slope basin, Seismic and high-resolution reflection profiles reveal that a prominent unconformity marks the base of the Paola Basin System (PBS), The unconformity connects upslope to an area of recurrent shelf edge instability and is overlain by large mass-failure deposits over much of the basin area, Basin-wide sedimentary drape deposits form stratigraphic markers that subdivide the Paola Basin System into three stages, each with unique patterns of slope erosion, including mass wasting, and lower slope to basin-floor turbidite deposition, Three major sediment pathways elongated perpendicular to the margin developed between the unconformity and the first basin wide drape, Upsection, sediment input for turbidite sedimentation in Paola Basin has involved many, commonly ephemeral, point sources, Most of the turbidite deposits do not form complete submarine fan sequences but consist of only a few turbidite elements, Changes in the size and type of turbidite elements through time suggest a decrease in the size and/or duration of individual sediment sources in the latest Pleistocene. The Paola Basin System is an example of a complex fill of a tectonically controlled basin where the effects of cyclic eustatic changes in sea level modify the effects of longer-term changes in sedimentation driven by tectonic activity in the source region and structural deformation in the depositional area. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP TRINCARDI, F (reprint author), IST GEOL MARINA,I-40129 BOLOGNA,ITALY. RI Correggiari, Annamaria/I-6628-2013; Correggiari, Annamaria/J-3413-2013 OI Correggiari, Annamaria/0000-0001-9820-5423 NR 55 TC 16 Z9 16 U1 0 U2 5 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 1073-1318 J9 J SEDIMENT RES B JI J. Sediment. Res.-Sect. B-Stratigr. Glob. Stud. PD NOV 15 PY 1995 VL 65 IS 4 BP 469 EP 483 PG 15 WC Geology SC Geology GA TH904 UT WOS:A1995TH90400005 ER PT J AU LAWRENCE, GB DAVID, MB SHORTLE, WC AF LAWRENCE, GB DAVID, MB SHORTLE, WC TI A NEW MECHANISM FOR CALCIUM LOSS IN FOREST-FLOOR SOILS SO NATURE LA English DT Article ID ACIDIC DEPOSITION; ACIDIFICATION; WATERS AB CALCIUM is the fifth most abundant element in trees, and is an essential component for wood formation and the maintenance of cell walls. Depletion of Ca from the rooting zone can result in acidification of soil(1) and surface water(2) and possibly growth decline and dieback of red spruce(3,4). During the past six decades, concentrations of root-available Ca (exchangeable and acid-extractable forms) in forest-floor soils have decreased in the northeastern United States(5,6). Both net forest growth and acid deposition have been put forth as mechanisms that can account for this Ca depletion(5,6). Here, however, we present data collected in red spruce forests in the northeastern United States that are inconsistent with either of these mechanisms. We propose that aluminium, mobilized in the mineral soil by acid deposition, is transported into the forest floor in a reactive form that reduces storage of Ca, and thus its availability for root uptake. This results in potential stress to trees and, by increasing the demand for Ca, also decreases neutralization of drainage waters, thereby leading to acidification of lakes and streams. C1 UNIV ILLINOIS,URBANA,IL 61801. US FOREST SERV,NE FOREST EXPT STN,DURHAM,NH 03824. RP LAWRENCE, GB (reprint author), US GEOL SURVEY,425 JORDAN RD,TROY,NY 12180, USA. NR 28 TC 148 Z9 156 U1 3 U2 24 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 9 PY 1995 VL 378 IS 6553 BP 162 EP 165 DI 10.1038/378162a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TD759 UT WOS:A1995TD75900046 ER PT J AU Haselton, HT Chou, IM Shen, AH Bassett, WA AF Haselton, HT Chou, IM Shen, AH Bassett, WA TI Techniques for determining pressure in the hydrothermal diamond-anvil cell: Behavior and identification of ice polymorphs (I, III, V, VI) SO AMERICAN MINERALOGIST LA English DT Article ID EQUATION; WATER; TEMPERATURES; TRANSITION; QUARTZ; STATE; KBAR AB For H2O densities > 1.0 g/cm(3), a determination of the ice melting temperature provides the density information required to calculate the P-T path that the sample in a hydrothermal diamond-anvil cell follows when the sample is heated isochorically. The principal difficulty is the identification of the polymorph because of metastable behavior of ices in the H2O system. Usually, an accurate identification of the liquidus ice phase can be made without analytical instrumentation and requires only careful observations. C1 CORNELL UNIV,DEPT GEOL SCI,ITHACA,NY 14853. RP Haselton, HT (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. RI Shen, Andy/M-5001-2013 OI Shen, Andy/0000-0003-2929-683X NR 17 TC 23 Z9 24 U1 0 U2 0 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1995 VL 80 IS 11-12 BP 1302 EP 1306 PG 5 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TK917 UT WOS:A1995TK91700021 ER PT J AU Peng, GY Lewis, J Lipin, B McGee, J Bao, PS Wang, XB AF Peng, GY Lewis, J Lipin, B McGee, J Bao, PS Wang, XB TI Inclusions of phlogopite and phlogopite hydrates in chromite from the Hongguleleng ophiolite in Xinjiang, northwest China SO AMERICAN MINERALOGIST LA English DT Article ID UPPER MANTLE PERIDOTITES; COMPOSITIONAL VARIATION; SODIUM PHLOGOPITE; OMAN OPHIOLITE; FLUID PHASE; SPINEL; DEPOSITS; ORIGIN; XENOLITHS; MICAS AB Two types of chromite deposits occur in the Hongguleleng ophiolite in Xinjiang, northwest China. One is located in the mantle sequence, the other occurs in the transition zone between the mantle sequence and layered cumulates. Abundant primary silicate inclusions such as phlogopite, pargasite, clinopyroxene, orthopyroxene, and olivine are found in the segregated chromite, but silicate inclusions occur only rarely in accessory chromite of the ultramafic rocks from the transition zone and cumulates. These silicate phases are considered to have been entrapped as discrete and rare composite inclusions during magmatic precipitation of chromite rather than formed by postmagmatic entrapment. Phlogopite is the most abundant mineral found as inclusions in chromite in the Hongguleleng ophiolite. There are two types of substitutions for K in the phlogopite inclusions: (1) Na substitutes for K, and phlogopite shows a continuous range from almost pure sodium phlogopite to phlogopite; (2) Ca partially substitutes for K, resulting in the formation of Ca-bearing phlogopite. It is proposed that the alkalic aqueous liquid (melt) responsible for the formation of the phlogopite inclusions was derived from the mixture of the K-rich aqueous liquid related to the subduction of the oceanic slab and the Na-rich aqueous liquid from the primary magma of the ophiolite. Two types of phlogopite hydrates, hydrate I and possibly a new hydrate (hydrate H), occur as inclusions in the chromite and result from later hydrothermal processes. The fractures from brittle deformation provided passage for meteoric water to enter and react with the phlogopite inclusions. Compared with those in the transition zone, the inclusions of phlogopite and phlogopite hydrates in the mantle sequence are characterized by (1) smaller grain size and greater abundance, (2) undulatory extinction, (3) higher Si, Cr, Ni, and Ca, and (4) lower Ti and Al. These differences are possibly due to (I) P, T, and composition of chromite-precipitating magma, (2) subsolidus reequilibration with the host chromite, and (3) postmagmatic deformation and hydrothermal processes. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. CHINESE ACAD MED SCI,INST GEOL,BEIJING 100037,PEOPLES R CHINA. RP Peng, GY (reprint author), GEORGE WASHINGTON UNIV,DEPT GEOL,WASHINGTON,DC 20052, USA. NR 56 TC 22 Z9 22 U1 0 U2 2 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1995 VL 80 IS 11-12 BP 1307 EP 1316 PG 10 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TK917 UT WOS:A1995TK91700022 ER PT J AU Helz, RT AF Helz, RT TI The Stillwater Complex, Montana: A subvolcanic magma chamber? SO AMERICAN MINERALOGIST LA English DT Letter ID ULTRAMAFIC SERIES; BUSHVELD COMPLEX; EVOLUTION; CRYSTALLIZATION; PETROGENESIS; SILLS AB Five magma types occur as sills in the footwall of the Stillwater Complex, all of them coeval with the Stillwater in age. Two of the magma types have compositions that suggest they are similar to the magmas from which the cumulates of the Stillwater's Basal and Ultramafic series crystallized. Melting experiments performed on samples of these two magma types and on a 50-50 mix of the two types show that the crystallization sequence inferred from the Ultramafic series cumulates (olivine > orthopyroxene > plagioclase > augite) is matched only in the mixture of the two sill types at 1.5-3 kbar. Thus, the observed stratigraphy of the Basal and Ultramafic series may result from mixing of two distinct magmas rather than fractionation of a single magma. The permissible pressure range of 1.5-3 kbar implies that the depth of the Stillwater magma chamber was similar to that of subvolcanic magma chambers such as that of Kilauea Volcano, which raises the possibility that the Stillwater magma body may also have been a subvolcanic reservoir. RP Helz, RT (reprint author), US GEOL SURVEY,MS 107,RESTON,VA 22092, USA. NR 25 TC 10 Z9 11 U1 0 U2 1 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1995 VL 80 IS 11-12 BP 1343 EP 1346 PG 4 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TK917 UT WOS:A1995TK91700027 ER PT J AU GUO, X LICHTE, FE AF GUO, X LICHTE, FE TI ANALYSIS OF ROCKS, SOILS AND SEDIMENTS FOR THE CHALCOPHILE ELEMENTS BY LASER ABLATION-INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY SO ANALYST LA English DT Article DE CHALCOPHILE ELEMENT; LASER ABLATION; INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY; FIRE ASSAY; TRACE ELEMENT ANALYSIS ID ATOMIC-ABSORPTION SPECTROMETRY; QUANTIFICATION; ELIMINATION; METEORITES AB A method of analysis was developed to determine several chalcophile elements in geological materials by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), Instrumental parameters and response factors affecting the results mere established and then optimized, The chalcophile elements were concentrated by a fire-assay technique using Ni and S powders. The resulting metal alloy bead was used for direct laser sampling into an ICP-MS instrument. Recovery of most chalcophile elements was >95%, The limits of detection ranged from <1(Ag) to 100 (Te) ng g(-1) in the sample. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 15 TC 14 Z9 14 U1 1 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0003-2654 J9 ANALYST JI Analyst PD NOV PY 1995 VL 120 IS 11 BP 2707 EP 2711 DI 10.1039/an9952002707 PG 5 WC Chemistry, Analytical SC Chemistry GA TE861 UT WOS:A1995TE86100009 ER PT J AU HOTHEM, RL ZADOR, SG AF HOTHEM, RL ZADOR, SG TI ENVIRONMENTAL CONTAMINANTS IN EGGS OF CALIFORNIA LEAST TERNS (STERNA-ANTILLARUM-BROWNI) SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID COMMON TERNS; REPRODUCTION; RESIDUES; SELENIUM; MERCURY C1 US FISH & WILDLIFE SERV,SAN FRANCISCO BAY NATL WILDLIFE REFUGE,NEWARK,CA 94560. RP HOTHEM, RL (reprint author), UNIV CALIF DAVIS,DEPT WILDLIFE FISH & CONSERVAT BIOL,NATL BIOL SERV,CALIF PACIFIC SCI CTR,DAVIS,CA 95615, USA. NR 22 TC 13 Z9 15 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD NOV PY 1995 VL 55 IS 5 BP 658 EP 665 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RU629 UT WOS:A1995RU62900004 PM 8563197 ER PT J AU RIEHLE, JR MILLER, TF BAILEY, RA AF RIEHLE, JR MILLER, TF BAILEY, RA TI COOLING, DEGASSING AND COMPACTION OF RHYOLITIC ASH-FLOW TUFFS - A COMPUTATIONAL MODEL SO BULLETIN OF VOLCANOLOGY LA English DT Article DE IGNIMBRITE; PYROCLASTS; COMPACTION; TUFFS; MATAHINA IGNIMBRITE ID BISHOP-TUFF; CALIFORNIA; DEPOSITS; ALASKA AB Previous models of degassing, cooling and compaction of rhyolitic ash flow deposits are combined in a single computational model that runs on a personal computer. The model applies to a broader range of initial and boundary conditions than Riehle's earlier model, which did not integrate heat and mass flux with compaction and which for compound units was limited to two deposits. Model temperatures and gas pressures compare well with simple measured examples. The results indicate that degassing of volatiles present at deposition occurs within days to a few weeks. Compaction occurs for weeks to two to three years unless halted by devitrification; near-emplacement temperatures can persist for tens of years in the interiors of thick deposits. Even modest rainfall significantly chills the upper parts of ash deposits, but compaction in simple cooling units ends before chilling by rainwater influences cooling of the interior of the sheet. Rainfall does, however, affect compaction at the boundaries of deposits in compound cooling units, because the influx of heat from the overlying unit is inadequate to overcome heat previously lost to vaporization of water. Three density profiles from the Matahina Ignimbrite, a compound cooling unit, are fairly well reproduced by the model despite complexities arising from numerous cooling breaks. Uncertainties in attempts to correlate in detail among the profiles may be the result of the non-uniform distribution of individual deposits. Regardless, it is inferred that model compaction is approximately valid. Thus the model should be of use in reconstructing the emplacement history of compound ash deposits, for inferring the depositional environments of ancient deposits and for assessing how long deposits of modern ash flows are capable of generating phreatic eruptions or secondary ash flows. C1 PENN STATE UNIV,APPL RES LAB,STATE COLL,PA 16804. US GEOL SURVEY,MENLO PK,CA 94025. RP RIEHLE, JR (reprint author), US GEOL SURVEY,4200 UNIV DR,ANCHORAGE,AK 99508, USA. NR 60 TC 73 Z9 73 U1 1 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD NOV PY 1995 VL 57 IS 5 BP 319 EP 336 DI 10.1007/BF00301291 PG 18 WC Geosciences, Multidisciplinary SC Geology GA TH946 UT WOS:A1995TH94600004 ER PT J AU Amstrup, SC Garner, GW Cronin, MA Patton, JC AF Amstrup, SC Garner, GW Cronin, MA Patton, JC TI Sex identification of polar bears from blood and tissue samples (vol 71, pg 2174, 1993) SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Correction, Addition C1 LGL ECOL GENET INC,BRYAN,TX 77801. LGL ALASKA RES ASSOCIATES INC,ANCHORAGE,AK 99508. RP Amstrup, SC (reprint author), US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. NR 1 TC 1 Z9 1 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD NOV PY 1995 VL 73 IS 11 BP 2169 EP 2169 DI 10.1139/z95-256 PG 1 WC Zoology SC Zoology GA TQ063 UT WOS:A1995TQ06300025 ER PT J AU Deuser, WG Jickells, TD King, P Commeau, JA AF Deuser, WG Jickells, TD King, P Commeau, JA TI Decadal and annual changes in biogenic opal and carbonate fluxes to the deep Sargasso Sea SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID LONG-TERM TRENDS; LARGE OCEANIC DIATOMS; NORTH PACIFIC-OCEAN; SURFACE-OCEAN; VARIABILITY; ATLANTIC; PHYTOPLANKTON; SEDIMENTS; CLIMATE; WATER AB Analyses of samples from a 14-year series of sediment-trap deployments in the deep Sargasso Sea reveal a significant trend in the ratio of the sinking fluxes of biogenic calcium carbonate and silica. Although there are pronounced seasonal cycles for both flux components, the overall opal/CaCO3 ratio changed by 50% from 1978 to 1991 (largely due to a decrease of opal flux), while total flux had no significant trend. These results suggest that plankton communities respond rapidly to subtle climate change, such as is evident in regional variations of wind speed, precipitation, wintertime Ventilation and midwater temperatures. If the trends we observe in the makeup of sinking particulate matter occur on a large scale, they may in turn modify climate by modulating ocean-atmosphere CO2 exchange and albedo over the ocean. C1 UNIV E ANGLIA,SCH ENVIRONM SCI,NORWICH NR4 7TJ,NORFOLK,ENGLAND. US GEOL SURVEY,WOODS HOLE,MA 02540. RP Deuser, WG (reprint author), WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02540, USA. NR 44 TC 48 Z9 48 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD NOV-DEC PY 1995 VL 42 IS 11-12 BP 1923 EP 1932 DI 10.1016/0967-0637(95)00093-3 PG 10 WC Oceanography SC Oceanography GA TM669 UT WOS:A1995TM66900005 ER PT J AU VERPLANCK, PL FARMER, GL MCCURRY, M MERTZMAN, S SNEE, LW AF VERPLANCK, PL FARMER, GL MCCURRY, M MERTZMAN, S SNEE, LW TI ISOTOPIC EVIDENCE ON THE ORIGIN OF COMPOSITIONAL LAYERING IN AN EPIZONAL MAGMA BODY SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID NEW-MEXICO; VOLCANIC FIELD; CHAMBERS; GRADIENTS; EVOLUTION; ASSIMILATION; GRANITE; FLOW; ND AB A detailed isotopic study of the Oligocene age (36 Ma), alkaline composition Organ Needle pluton in south-central New Mexico was undertaken to test models for the generation of compositional layering in silicic, epizonal magma bodies. The pluton is isotopically heterogeneous with its alkali feldspar granite composition cap (73-76% SiO2) having lower initial epsilon(Nd) and higher Sr-87/Sr-86 ratio than the underlying main syenite (-5 vs. -2 and similar to 0.709 vs. similar to 0.706, respectively). Both lithologies have isotopic compositions significantly different from those of the Precambrian granite wall-rock(epsilon(Nd) similar to -12.1 and Sr-87/Sr-86 similar to 0.784 at 36 Ma). The isotope data indicate that none of the lithologies of the pluton represent the products solely of roof or wall-rock melting, and that the capping granite could not have been derived in a closed-system from differentiation of the underlying syenitic magma. However, the capping granite has isotopic compositions similar to those of a chemically heterogeneous inequigranular syenite found along the margin of the pluton at its deepest exposed level (4-6 km paleodepth). Field observations, and new Ar-40/Ar-39 age determinations, confirm that this lithology was comagmatic with the remainder of the pluton. We conclude that the capping granitic magma was derived from buoyant epsilon(Nd) similar to -5 magma rising along the margins of the magma chamber and that the inequigranular syenite preserves a remnant of this sidewall magma. The main syenite body was encapsulated in this marginal, lower epsilon(Nd), magma, while undergoing closed-system differentiation, most likely from a mafic progenitor. The epsilon(Nd) = -5 magma may represent mafic magma initially equivalent isotopically to the main syenite but which subsequently assimilated Precambrian wall-rock (similar to 10% by mass) at the base of the magma system. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT GEOL SCI, BOULDER, CO 80309 USA. IDAHO STATE UNIV, DEPT GEOL, POCATELLO, ID 83209 USA. FRANKLIN & MARSHALL COLL, DEPT GEOSCI, LANCASTER 17604, ENGLAND. US GEOL SURVEY, DENVER, CO 80225 USA. NR 22 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X EI 1385-013X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD NOV PY 1995 VL 136 IS 1-2 BP 31 EP 41 DI 10.1016/0012-821X(95)00147-6 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH182 UT WOS:A1995TH18200003 ER PT J AU Goldhaber, MB Church, SE Doe, BR Aleinikoff, JN Brannon, JC Podosek, FA Mosier, EL Taylor, CD Gent, CA AF Goldhaber, MB Church, SE Doe, BR Aleinikoff, JN Brannon, JC Podosek, FA Mosier, EL Taylor, CD Gent, CA TI Lead and sulfur isotope investigation of Paleozoic sedimentary rocks from the southern midcontinent of the United States: Implications for paleohydrology and ore genesis of the southeast Missouri lead belts SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID MISSISSIPPI VALLEY-TYPE; OIL-FIELD BRINES; VIBURNUM-TREND; GENETIC-IMPLICATIONS; FLUID INCLUSIONS; BARITE DEPOSITS; ZINC DEPOSITS; NORTH-AMERICA; OZARK REGION; BUICK MINE AB This study utilizes Pb isotope data to identify flow paths and Pb sources for Mississippi Valley-type ores in the midcontinent of the United States with emphasis on the Old and Nerv Lead Belt subdistricts bf southeast Missouri. Nearly 150 new analyses are reported which characterize the,isotope systematics of both ore samples and Pb hosted by sedimentary rocks away from ore districts. A subset of the samples has been analyzed for sulfur isotopes. The nonore samples contain trace amounts of Pb largely hosted by trace metal-rich FeS2 (termed ''sulfide trace Pb''). These metal-rich sulfide phases are constrained by previous petrographic studies to have precipitated from the mineralizing fluids responsible for Mississippi Valley-type ore formation. Sampling was designed to evaluate the role of potential Cambrian and Ordovician aquifers as transport paths for Pb and S in an area broadly surrounding the locus of lead belt mineralization in southeast Missouri. Analyses are also presented for various leach fractions of rocks (termed ''rock Pb'') associated with these same potential aquifer units. Analyses of ore samples establish important benchmarks with which to compare the nonore samples. Ore samples were analyzed from southeast Missouri and include new data for both galena and nongalena phases (chalcopyrite, sphalerite, dolomite) from the New Lead belt subdistrict (Viburnum Trend subdistrict), and galena from the Old Lead Belt subdistrict and the outlying subdistricts of Annapolis and Indian Creek. Also studied were galena samples from the Central Missouri and Tri-State districts. The new data plus published values from the Northern Arkansas and Upper Mississippi Valley districts are nearly collinear on a uranogenic Pb isotope plot (Pb-206/Pb-204 vs. Pb-207/Pb-204). The slope of the linear regression line through this data is consistent with all the ores having been derived from the approximately 1450 Ma basement in the midcontinent area. However, the ores are very clearly separated on a plot of thorogenic isotope data (Pb-206/Pb-204 vs. Pb-208/Pb-204). Ores from either end of the Illinois basin, the Upper Mississippi Valley and Illinois-Kentucky fluorspar districts, have markedly higher Pb-208/Pb-204 for a given Pb-206/Pb-204 compared to ores from the ore districts in the Ozark region. Conversely, data from main-stage galena samples from the Viburnum Trend (which are commonly cube octahedral in morphology but which may also be disseminated in the host rock) and limited data from the Old Lead Belt are notable for having a lower Pb-208/Pb-204 for a given Pb-206/Pb-204 compared not only to Illinois basin-associated ores but also compared to data from other districts in the Ozark region and even to paragenetically later, and volumetrically minor, cubic-stage mineralization data from the Viburnum Trend itself. Identifying the transport path and source for the Pb-208-depleted main-stage ores of the lead belts was a major goal of this study. Uranogenic Pb isotope data for sulfide trace Pb samples are generally collinear with ore Pb data. This similarity indicates that a basement source is also possible for sulfide trace Pb; however,the thorogenic isotopic plot shows much more complexity. Pb isotope data from samples of dominantly dolomitic Cambrian and Ordovician units younger than the Upper Cambrian Bonneterre Formation form an array which is collinear with data from the Northern Arkansas, Tri State, and Central Missouri districts and with the most radiogenic values from the late-stage cubic mineralization. This array is Significantly enriched in Pb-208 compared to main-stage Viburnum Trend mineralization. Data from the Bonneterre Formation, which hosts ore in the lead belts, show more scatter but tend to show even more Pb-208 enrichment compared to main-stage lead belt data. This trend toward increased scatter and increased Pb-208 enrichment continues to be supported by isotopic data from the underlying, coarse elastic Lamotte Sandstone, which many have postulated as a major aquifer for ore genesis in southeast Missouri. Thus, an extensive data set from a large area surrounding the lead belts failed to identify the isotopic tracks of Pb-208-depleted main-stage lend belt mineralization in aquifer units hosting sulfide-associated Pb, but did identify potential aquifers associated with dolomitic, post-Bonne-terre Cambrian rocks for Pb transport to less Pb-rich Mississippi Valley-type districts such as Tri-State, Northern Arkansas, and Central Missouri. The sulfide trace Pb samples present data which show that they are systematically enriched in S-32 (i.e., delta(34)S < 10%) compared to samples of main-stage ores of the Viburnum Trend (delta(34)S > 10 parts per thousand), although isotopically heavy trace sulfides are localized in the upper Bonneterre Formation. Combined Pb and S isotope data for sulfide trace Pb samples do not reflect the signature expected of a single, unique Mississippi Valley-type ore-forming fluid for the lead belts but are indicative of a fluid which could have represented the isotopically light S and slightly Pb-208-enriched end member of a mixture. Pb isotope data from leaches of rock samples from the Bonneterre Formation (a predominantly carbonate unit) and the elastic Lamotte Sandstone are easily distinguishable. On a thorogenic isotope plot, the Bonneterre Formation results, from both limestones and dolomites, form a linear array that is in good agreement with the array formed by sulfide trace Pb samples hosted by carbonate rock units (i.e., exclusive of the Lamotte Sandstone). The combined Pb isotope array, which we term the ''midcontinent carbonate Pb line'' is interpreted to reflect both sources of Pb (primary limestone and premineralization dolomite) and sinks (trace Pb,in sulfides and ore-stage hydrothermal dolomite). The slope of the uranogenic plot for the midcontinent carbonate Pb line, which gives an age similar to that of both ores and basement rocks, is interpreted to indicate an ultimate basement source for the uranium in these units, but some preferential transport and incorporation of U over Th did occur during formation of these rocks. A major finding of this study is that thorogenic Pb isotope data on sock Pb from the Lamotte Sandstone (supported by published data on Pb trapped in presumed ore-stage authigenic K feldspar) yield the Pb-208-depleted isotope signature expected for rocks of a transport path of main-stage Pb. The marked contrast between the lower Pb-208 values for rock Pb and higher Pb-208 values for sulfide-associated Pb in the Lamotte Sandstone is interpreted to reflect the geochemical evolution of this formation during the mineralizing event. Initially the Lamotte Sandstone contained hematite as a result of early diagenetic processes (i.e., red-bed formation). During early stages of ore genesis in southeast Missouri, fluids transported through the Lamotte Sandstone were buffered to high f(o2) (low H2S) by this hematite. The lack of H2S allowed effective leaching and transport of high concentrations of Pb (and probably Cu) by the warm saline brines. The source of this lead was probably the Lamotte Sandstone itself plus the upper (weathered?) portion of the Precambrian basement. Subsequently, bleaching (hematite removal) permitted the accumulation of H2S in the Lamotte Sandstone aquifer fluids. This transition from H2S-free to H2S-bearing fluids also coincided with a shift in Pb source from weathered and modified rocks (Lamotte Sandstone and upper basement), to much more thorogenic Pb in the unweathered basement. Other potential source regions for southeast Missouri Pb can be ruled out on the basis of data from this study. Both sulfide trace Pb and ores from the Illinois basin region are markedly enriched in Pb-208 compared to main-stage ores of the lead belts and thus did not contribute significantly. Likewise, analyses of rock Pb in the Reelfoot rift and sulfide trace Pb in sediments immediately adjacent to the rift margin are collinear with Illinois basin Pb isotopes on a thorogenic Pb plot and thus sediments of the rift are unsuitable Pb sources. The isotopic systematics of both Illinois basin and Reelfoot rift ores and sedimentary Pb samples are indicative of Pb leached from unmodified basement. Based on the results of this study, the main-stage ores of the southeast Missouri lead belts involved the mixing of fluids traveling along three separate aquifers. Most of the Pb, and specifically the distinctive Pb-208-depleted component, was transported through the Lamotte Sandstone. Isotopically heavy H2S migrated in the upper Bonneterre Formation (Sullivan Siltstone Member), and both Ph and isotopically light H2S were migrating in the carbonate section (exclusive of the upper Bonneterre). These fluids were forced to mix by profound sedimentological changes in the vicinity of the St. Francois Mountains. The Lamotte Sandstone locally pinches out against basement highs, and the overlying Bonneterre Formation undergoes a facies change from a fine-grained, basinal shale and micrite-confining bed, to a more porous and permeable dolomite. Both these changes permitted upward movement of fluid from the Lamotte Sandstone. Simultaneously, the fluid migrating in the upper Bonneterre Formation was forced to disperse because of the pinchout of the Sullivan Siltstone Member. Finally, the fluid carrying isotopically light H2S and Pb from the carbonates was plumbed into the ore zone along porous ''white rock'' zones which pinch out near the ore zones but extend for long distances to the south. This specific fluid-mixing hypothesis explains many key isotopic and textural characteristics of the ores. Ores formed stratigraphically higher in the section were progressively less influenced by Pb derived from the Lamotte Sandstone-basement and contain a progressively larger fraction of Ph derived from the carbonate portion of the section. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22093. WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,MCDONNELL CTR SPACE SCI,ST LOUIS,MO 63130. RP Goldhaber, MB (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 973,DENVER,CO 80225, USA. NR 99 TC 54 Z9 60 U1 6 U2 18 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD NOV PY 1995 VL 90 IS 7 BP 1875 EP 1910 PG 36 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UB414 UT WOS:A1995UB41400001 ER PT J AU Rowan, LC Bowers, TL Crowley, JK AntonPacheco, C Gumiel, P Kingston, MJ AF Rowan, LC Bowers, TL Crowley, JK AntonPacheco, C Gumiel, P Kingston, MJ TI Analysis of airborne visible infrared imaging spectrometer (AVIRIS) data of the Iron Hill, Colorado, carbonatite alkalic igneous complex SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SPECTRAL REFLECTANCE; VEGETATION; MINERALS; CALIFORNIA; ABUNDANCE; DESERTS; ROCKS; SOIL AB The Iron Hill, Colorado, carbonatite-alkalic igneous rock complex consists mainly of pyroxenite, uncompahgrite, fenite and nepheline syenite, and carbonatite. The study area has been explored intermittently for several decades for thorium, niobium, rare earth elements, titanium, and vermiculite. Airborne visible-infrared imaging spectrometer (AVIRIS) data were acquired for the Iron Hill Complex on August 28, 1992, under clear sky conditions. The data were calibrated using a laboratory reflectance spectrum of a tuff-sagebrush mixture to represent the spectral response of a topographically flat, homogeneous image area within the ash-flow tuff. Analysis of the data was conducted using the spectral angle mapper (SAM) and linear spectral unmixing algorithms in the spectral image processing system (SIPS). Image spectra in the 2.1- to 2.45-mu m wavelength region were used in the SAM method to map dolomite in the Iron Hill carbonatite (rauhaugite) stock and in several smaller bodies, calcite in a small carbonatite (sovite) plug and in travertine spring deposits, illite mainly in sericitized felsite and granite, and kaolinite in hydrothermally altered ash-flow tuff. The general distribution of the main alkalic igneous rocks (pyroxenite, uncompahgrite, and ijolite) was mapped using a full AVIRIS wavelength range (0.40-2.45 mu m) image spectrum of pyroxenite, excluding channels affected by strong atmospheric absorption. However, some areas consisting of felsite and fenite were not spectrally distinguished from the alkalic rocks. Linear spectral unmixing, using full wavelength image spectra, was used to improve the compositional mapping achieved using the SAM algorithm. The fractional abundance images obtained for dolomite and calcite were similar to the SAM results, but the distinction between illite and kaolinite was significantly improved, especially where scattered coniferous trees are resent. Hematite and goethite, which showed widely overlapping patterns in the SAM similarity images, were distinguished much better in the fractional abundance images. Biotite was used instead of pyroxenite as a reference end member in the unmixing analysis, and the results were better than those obtained in the SAM analysis. The results of the unmixing analysis show the potential for using imaging spectrometer data for identifying and mapping carbonate minerals within carbonatite bodies and hot spring deposits and biotite within pyroxenite. In addition, the most intense Al-OH absorption features occur in sericitized granite and felsite associated with thorium veins and in kaolinite in hydrothermally altered tuff. Concentrations of kaolinite, travertine, and silicified carbonatite along the trace of the Cimarron fault indicate that the fault was reactivated after deposition of the Tertiary tuff and provided a conduit for fluids. C1 INST TECNOL GEOMINERO ESPANA, E-28003 MADRID, SPAIN. RP Rowan, LC (reprint author), US GEOL SURVEY, MAIL STOP 954, RESTON, VA 22092 USA. NR 34 TC 20 Z9 22 U1 1 U2 5 PU SOC ECONOMIC GEOLOGISTS, INC PI LITTLETON PA 7811 SCHAFFER PARKWAY, LITTLETON, CO 80127 USA SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD NOV PY 1995 VL 90 IS 7 BP 1966 EP 1982 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UB414 UT WOS:A1995UB41400006 ER PT J AU Dickison, WR Force, ER Hagstrum, JT AF Dickison, WR Force, ER Hagstrum, JT TI Tilting history of the San Manuel-Kalamazoo porphyry system, southeastern Arizona - A reply SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Discussion C1 UNIV ARIZONA,US GEOL SURVEY,TUCSON,AZ 85721. US GEOL SURVEY,MENLO PK,CA 94025. RP Dickison, WR (reprint author), UNIV ARIZONA,DEPT GEOL SCI,GOULD SIMPSON BLDG,TUCSON,AZ 85721, USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD NOV PY 1995 VL 90 IS 7 BP 2096 EP 2098 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UB414 UT WOS:A1995UB41400020 ER PT J AU BRADLEY, PM CHAPELLE, FH AF BRADLEY, PM CHAPELLE, FH TI RAPID TOLUENE MINERALIZATION BY AQUIFER MICROORGANISMS AT ADAK, ALASKA - IMPLICATIONS FOR INTRINSIC BIOREMEDIATION IN COLD ENVIRONMENTS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article AB Sediments from a relatively cold (5 degrees C), petroleum hydrocarbon-contaminated aquifer in Adak, AK, mineralized [C-14]toluene at an aerobic rate (16.3% day(-1) at 5 degrees C) comparable to that (5.1% day(-1) at 20 degrees C) of sediments from a more temperate aquifer at Hanahan, SC. In addition, rates of overall microbial metabolism in sediments from the two aquifers, as estimated by [1-C-14]acetate mineralization, were similar (similar to 10.6% h(-1)) at their respective in situ temperatures. These results are not consistent with the common assumption that biodegradation rates in cold groundwater systems are depressed relative to more temperate systems. Furthermore,these results suggest that intrinsic bioremediation of petroleum hydrocarbon contaminants in cold groundwater systems may be technically feasible, in some cases. RP BRADLEY, PM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,STEPHENSON CTR,SUITE 129,720 GRACERN RD,COLUMBIA,SC 29210, USA. NR 13 TC 28 Z9 28 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV PY 1995 VL 29 IS 11 BP 2778 EP 2781 DI 10.1021/es00011a012 PG 4 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TC856 UT WOS:A1995TC85600030 PM 22206524 ER PT J AU LEBO, JA GALE, RW PETTY, JD TILLITT, DE HUCKINS, JN MEADOWS, JC ORAZIO, CE ECHOLS, KR SCHROEDER, DJ AF LEBO, JA GALE, RW PETTY, JD TILLITT, DE HUCKINS, JN MEADOWS, JC ORAZIO, CE ECHOLS, KR SCHROEDER, DJ TI USE OF THE SEMIPERMEABLE-MEMBRANE DEVICE AS AN IN-SITU SAMPLER OF WATERBORNE BIOAVAILABLE PCDD AND PCDF RESIDUES AT SUB-PARTS-PER-QUADRILLION CONCENTRATIONS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CONTAMINANTS; HYDROCARBONS; EQUIVALENTS; BIOASSAY; DIOXINS; SYSTEMS; SPMDS AB Semipermeable membrane devices (SPMDs) were used to passively sample aqueous polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in Bayou Meto, AR. The two sites were upstream and downstream from the confluence with a tributary that delivers PCDDs and PCDFs to the Bayou. Following dialysis, cleanup, and fractionation, four replicate 17-g SPMD samples from each site were analyzed by GC/MS, and four were evaluated by H4IIE bioassay. Traces of only OCDD and HpCDDs were detected in samples from the upstream site. The four samples from below the tributary contained averages of 1550 +/- 80 pg of 2,3,7,8-TCDD, 1640 +/- 80 pg of 2,3,7,8-TCDF, and lesser quantities of other congeners. The TCDD equivalents obtained by bioassay of replicate SPMD samples agreed well with results obtained by GC/MS. The quantities of 2,3,7,8-TCDD and 2,3,7,8-TCDF sequestered by SPMDs at the downstream site were used to estimate the aqueous concentrations for both compounds as 2 mu g/L. C1 US FISH & WILDLIFE SERV,VICKSBURG FIELD OFF,VICKSBURG,MS 39180. RP LEBO, JA (reprint author), US DEPT INTERIOR,NATL BIOL SERV,MIDWEST SCI CTR,4200 NEW HAVEN RD,COLUMBIA,MO 65201, USA. NR 46 TC 63 Z9 67 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV PY 1995 VL 29 IS 11 BP 2886 EP 2892 DI 10.1021/es00011a027 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TC856 UT WOS:A1995TC85600045 PM 22206539 ER PT J AU ELLIS, GS HUCKINS, JN ROSTAD, CE SCHMITT, CJ PETTY, JD MACCARTHY, P AF ELLIS, GS HUCKINS, JN ROSTAD, CE SCHMITT, CJ PETTY, JD MACCARTHY, P TI EVALUATION OF LIPID-CONTAINING SEMIPERMEABLE-MEMBRANE DEVICES FOR MONITORING ORGANOCHLORINE CONTAMINANTS IN THE UPPER MISSISSIPPI RIVER SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE SEMIPERMEABLE MEMBRANE DEVICE; ULTRAFILTRATION; ORGANOCHLORINE COMPOUNDS; FISH; MISSISSIPPI RIVER ID ORGANIC CONTAMINANTS; DIALYSIS; WATER; BIOCONCENTRATION; BIOACCUMULATION; POLLUTANTS; FISH AB Organochlorine contaminants sequestered in lipid-containing semipermeable membrane devices (SPMDs) were compared to those found in tangential-flow ultrafilter permeates as part of a pilot study at 10 sites in the Upper Mississippi River system. Caged and feral fish from three primary sites were also analyzed for comparison. Concentrated organochlorine (OC) compounds were readily extracted from the SPMDs by dialysis into hexane, and samples were analyzed by gas chromatography-negative chemical ionization-mass spectrometry. Fish and water samples were processed by conventional methods. Reasonable agreement was found between analyte SPMD-derived water concentrations and measured values of ultrafilter permeates; however, concentrations of the same analytes in caged fish did not appear to be proportional to water concentrations derived from SPMDs and ultrafilter permeates. The greatest number of OC compounds was detected in SPMDs; fewer were detected in caged fish and feral fish. C1 US NATL BIOL SERV,CTR MIDWEST SCI,COLUMBIA,MO 65201. COLORADO SCH MINES,DEPT CHEM & GEOCHEM,GOLDEN,CO 80401. US GEOL SURVEY,DIV WATER RESOURCES,ARVADA,CO 80002. OI Ellis, Geoffrey/0000-0003-4519-3320 NR 34 TC 89 Z9 91 U1 2 U2 12 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD NOV PY 1995 VL 14 IS 11 BP 1875 EP 1884 DI 10.1897/1552-8618(1995)14[1875:EOLSMD]2.0.CO;2 PG 10 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TB369 UT WOS:A1995TB36900009 ER PT J AU RIDLEY, WI AF RIDLEY, WI TI HYDROTHERMAL ALTERATION IN OCEANIC RIDGE VOLCANICS - A DETAILED STUDY AT THE GALAPAGOS FOSSIL HYDROTHERMAL FIELD (VOL 58, PG 2477 1994) SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Correction, Addition RP RIDLEY, WI (reprint author), US GEOL SURVEY,BRANCH GEOCHEM,MS 973,LAKEWOOD,CO 80225, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD NOV PY 1995 VL 59 IS 21 BP 4564 EP 4564 DI 10.1016/0016-7037(95)99269-M PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TE485 UT WOS:A1995TE48500017 ER PT J AU BERGGREN, WA HILGEN, FJ LANGEREIS, CG KENT, DV OBRADOVICH, JD RAFFI, I RAYMO, ME SHACKLETON, NJ AF BERGGREN, WA HILGEN, FJ LANGEREIS, CG KENT, DV OBRADOVICH, JD RAFFI, I RAYMO, ME SHACKLETON, NJ TI LATE NEOGENE CHRONOLOGY - NEW PERSPECTIVES IN HIGH-RESOLUTION STRATIGRAPHY SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Review ID MIOCENE-PLIOCENE BOUNDARY; POLARITY TIME-SCALE; PLANKTONIC FORAMINIFERAL DATUMS; CAPO-ROSSELLO AREA; BRUNHES-MATUYAMA; ASTRONOMICAL CALIBRATION; NORTH-ATLANTIC; PLEISTOCENE BOUNDARY; ICE AGES; SEA AB We present an integrated geochronology for late Neogene time (Pliocene, Pleistocene, and Holocene Epochs) based on an analysis of data from stable isotopes, magnetostratigraphy, radiochronology, and calcareous plankton biostratigraphy. Discrepancies between recently formulated astronomical chronologies and magneto-chronologies for the past 6 m.y. have been resolved on the basis of new, high-precision Ar/Ar ages in the younger part of this interval, the so-called Brunhes, Matuyama. and Gauss Epochs (= Chrons C1n-C2An; 0-3.58 Ma), and revised analysis of sea floor anomalies in the Pacific Ocean in the older part, the so-called Gilbert Epoch (= Chron C2Ar-C3r; 3.58-5.89 Ma). The magneto- and astrochronologies are now concordant back to the Chron C3r/C3 An boundary at 5.89 Ma. The Neogene (Miocene, Pliocene, Pleistocene, and Holocene) and Paleogene are treated here as period/system subdivisions of the Cenozoic Era/Erathem, replacements for the antiquated terms Tertiary and Qua ternary, The boundary between the Miocene and Pliocene Series (Messinian/Zanclean Stages), whose global stratotype section and point (GSSP) is currently proposed to be in Sicily, is located within the reversed interval just below the Thvera (C3n.4n) Magnetic Polarity Subchronozone with an estimated age of 5.32 Ma. The Pliocene/Pleistocene boundary, whose GSSP is located at Vrica (Calabria, Italy), is located near the top of the Olduvai (C2n) Magnetic Polarity Sub-chronozone with an estimated age of 1.81 Ma. The 13 calcareous nannoplankton and 48 planktonic foraminiferal datum events for the Pliocene, and 12 calcareous nannoplankton and 10 planktonic foraminiferal datum events for the Pleistocene, are calibrated to the newly revised late Neogene astronomical/geomagnetic polarity time scale. C1 UNIV UTRECHT,INST EARTH SCI,3584 CD UTRECHT,NETHERLANDS. COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964. US GEOL SURVEY,ISOTOPE GEOL BRANCH,DENVER,CO 80225. UNIV G DANNUNZIO,FAC SCI MM FF NN,CHIETI,ITALY. MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. UNIV CAMBRIDGE,GODWIN LAB QUATERNARY RES,CAMBRIDGE CB2 3RS,ENGLAND. RP BERGGREN, WA (reprint author), WOODS HOLE OCEANOG INST,DEPT GEOL & GEOPHYS,WOODS HOLE,MA 02543, USA. OI Langereis, Cor/0000-0001-9232-2178 NR 135 TC 294 Z9 309 U1 3 U2 32 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD NOV PY 1995 VL 107 IS 11 BP 1272 EP 1287 DI 10.1130/0016-7606(1995)107<1272:LNCNPI>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA TD519 UT WOS:A1995TD51900002 ER PT J AU DETHIER, DP PESSL, F KEULER, RF BALZARINI, MA PEVEAR, DR AF DETHIER, DP PESSL, F KEULER, RF BALZARINI, MA PEVEAR, DR TI LATE WISCONSINAN GLACIOMARINE DEPOSITION AND ISOSTATIC REBOUND, NORTHERN PUGET LOWLAND, WASHINGTON SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID RELATIVE SEA-LEVEL; BRITISH-COLUMBIA; LATE PLEISTOCENE; SOUTHEAST ALASKA; ISLAND; CANADA; SOUND; SHELF; GLACIATION; SEDIMENTS AB The distribution and age of glaciomarine and marine sediment in the northern Puget Lowland, Washington, demonstrate that rapid retreat of continental ice, the Everson marine incursion, and high rates of isostatic rebound occurred between about 13 600 and 11 300 C-14 yr B.P. (11.3 ka). Glaciomarine and marine deposits are thickest in zones where retreating ice lobes grounded, in the northeast Puget Lowland, and near large drainages. Glaciomarine sediment was deposited mainly from (1) submarine outwash in ice-proximal zones; (2) turbid underflows, dispersed melt water, icebergs, and resedimentation in transitional zones; and (3) dispersed melt water and currents in ice-distal zones, Marine, estuarine, and emergence (intertidal and beach) facies accumulated in areas more than 10 km from ice margins, particularly near major rivers. Molluscan and foraminiferal assemblages in the glaciomarine and marine deposits indicate that turbid, cool, brackish water covered much of the Puget Lowland during the Everson interval. Water was generally shallower (<30 m) in the southern part of the area and deeper (15-60 m) to the north. Mineralogy and geochemical properties such as boron or sodium content of the gravel-free fraction do not clearly distinguish glaciomarine and marine deposits from terrestrial deposits. Isostatic rebound rapidly lifted the glaciomarine and marine deposits through sea level between about 13.5 and 11.3 ka. The present altitudes of radiocarbon-dated shell and the marine limit show that initial rates of isostatic rebound exceeded 10 cm yr(-1) in the northern Puget Lowland, but dropped to 2 cm yr(-1) before 11 ka. The uplift gradient is about 0.6 m km(-1) to the north and steepens locally to at least 1.3 m km(-1). The pattern of emergence in the northern Puget Lowland is anomalous locally, perhaps as a result of complex isostatic effects near the glacier margin, rapid rise of sea level, or tectonic deformation. C1 US GEOL SURVEY,SEATTLE,WA 98105. UNIV WASHINGTON,SEATTLE,WA 98195. WESTERN WASHINGTON UNIV,BELLINGHAM,WA 98225. NR 78 TC 42 Z9 42 U1 0 U2 4 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD NOV PY 1995 VL 107 IS 11 BP 1288 EP 1303 DI 10.1130/0016-7606(1995)107<1288:LWGDAI>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA TD519 UT WOS:A1995TD51900003 ER PT J AU HAEUSSLER, PJ BRADLEY, D GOLDFARB, R SNEE, L TAYLOR, C AF HAEUSSLER, PJ BRADLEY, D GOLDFARB, R SNEE, L TAYLOR, C TI LINK BETWEEN RIDGE SUBDUCTION AND GOLD MINERALIZATION IN SOUTHERN ALASKA SO GEOLOGY LA English DT Article ID ACCRETIONARY PRISM; EASTERN GULF; FORE-ARC; CALIFORNIA; EVOLUTION; ORIGIN AB Ar-40/Ar-39 geochronology reveals that turbidite-hosted gold deposits in the southern Alaska accretionary prism are the same age as nearby near-trench plutons. These early Tertiary plutons and gold lodes formed above a slab window during subduction of an oceanic spreading center. Ridge subduction is a previously unrecognized tectonic process for the generation of lode gold. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP HAEUSSLER, PJ (reprint author), US GEOL SURVEY,4200 UNIV DR,ANCHORAGE,AK 99508, USA. OI Haeussler, Peter/0000-0002-1503-6247; Taylor, Cliff/0000-0001-6376-6298 NR 24 TC 90 Z9 99 U1 2 U2 7 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD NOV PY 1995 VL 23 IS 11 BP 995 EP 998 DI 10.1130/0091-7613(1995)023<0995:LBRSAG>2.3.CO;2 PG 4 WC Geology SC Geology GA TD518 UT WOS:A1995TD51800009 ER PT J AU YOUNG, JB PRESGRAVE, BW AF YOUNG, JB PRESGRAVE, BW TI THE POLITICAL SUBDIVISION OF SOUTHEAST-ASIA AND NORTHWEST AFRICA IN THE FLINN-ENGDAHL REGIONALIZATION SCHEME SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Note C1 US GEOL SURVEY,NATL EARTHQUAKE INFORMAT CTR,DENVER FED CTR,DENVER,CO 80225. RP YOUNG, JB (reprint author), AWE BLACKNEST,READING RG7 4RS,BERKS,ENGLAND. NR 6 TC 1 Z9 1 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD NOV PY 1995 VL 123 IS 2 BP 623 EP 627 DI 10.1111/j.1365-246X.1995.tb06876.x PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TD778 UT WOS:A1995TD77800021 ER PT J AU HARTE, PT WINTER, TC AF HARTE, PT WINTER, TC TI SIMULATIONS OF FLOW IN CRYSTALLINE ROCK AND RECHARGE FROM OVERLYING GLACIAL DEPOSITS IN A HYPOTHETICAL NEW-ENGLAND SETTING SO GROUND WATER LA English DT Article ID GROUNDWATER-FLOW; MODEL AB Cross-sectional, finite-difference, steady-state ground-water-flow models of a generalized New England landscape were constructed to examine the effects of hydraulic conductivity and topography on bulk-fluid flow processes in fractured crystalline rock. The generalized landscape consists of a flat hilltop, a hillside that has a slope of 0.17 ft/ft, and a net river valley. It includes three hydrogeologic units, stratified drift in the river valley, glacial till, and underlying crystalline rock. Distribution of recharge to and discharge from bedrock is affected by the presence of small topographic features, such as terraces on the hillside. Most of these terraces consist partly or entirely of sand, and they create localized areas of recharge to and discharge from bedrock, Maximum recharge to bedrock commonly occurs at downward inflections of the water table, and discharge occurs at upward inflections of the water table. These inflections of the water table are associated with inflections in topography because the shallow depth of water on hilltops and hillsides resemble the configuration of the land surface. Regional ground-water flow in crystalline rock and distribution of bedrock recharge and discharge are also affected by heterogeneities in hydraulic conductivity of the bedrock. Vertical heterogeneity creates short, shallow flow paths in high-relief terrain. Horizontal heterogeneity causes large variations in the size of bedrock recharge areas; in some cases the difference from homogeneous conditions is more than 50 percent. C1 US GEOL SURVEY,WRD,NRP,LAKEWOOD,CO 80225. RP HARTE, PT (reprint author), US GEOL SURVEY,WRD,525 CLINTON ST,BOW,NH 03301, USA. NR 42 TC 14 Z9 14 U1 1 U2 3 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1995 VL 33 IS 6 BP 953 EP 964 DI 10.1111/j.1745-6584.1995.tb00041.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TD127 UT WOS:A1995TD12700011 ER PT J AU SCHNOEBELEN, DJ BUGLIOSI, EF KROTHE, NC AF SCHNOEBELEN, DJ BUGLIOSI, EF KROTHE, NC TI DELINEATION OF A SALINE GROUNDWATER BOUNDARY FROM BOREHOLE GEOPHYSICAL-DATA SO GROUND WATER LA English DT Article ID BASIN AB This study uses borehole geophysical data to calculate the total dissolved solids (TDS) concentration of ground water in Devonian and Silurian carbonate aquifers in northern and southwestern Indiana and specifically, to delineate the 10,000 mg/l (milligrams per liter) TDS boundary, The 10,000 mg/l TDS boundary as used here refers to the transitional zone in the Devonian rocks where the TDS concentration of saline ground water changes from less than 10,000 mg/l to 10,000 mg/l or greater, The 10,000 mg/l boundary not only defines the maximum allowable TDS concentration recommended by the U.S. Environmental Protection Agency for potentially potable water, but also establishes an internal ''limit'' for the Silurian and Devonian carbonate aquifers in Indiana where density differences may be important for ground-water flow modeling. The study demonstrated that geophysical log data can provide a useful means of estimating TDS concentration in areas where water-quality data are lacking, found an excellent correlation between the resistivity-porosity method and measured TDS concentrations, and found several anomalous areas in Indiana where TDS concentration in Devonian and Silurian aquifers were higher or lower than expected. The TDS content of ground water in Devonian and some Silurian units was estimated by using three independent geophysical methods: static spontaneous-potential, mud-filtrate-resistivity, and resistivity-porosity. Each method yields values for formation-water resistivity (R(w)), from which TDS concentrations can be estimated. Calculated concentrations from each method were compared to available water-quality analyses. Use of the resistivity-porosity method produced the most accurate results, To help quantify the values used in the resistivity-porosity method, 19 samples cut from cores were evaluated by laboratory analyses. The static spontaneous-potential method was used only where data were not available for the resistivity-porosity method. The mud-filtrate-resistivity method yielded poor results and was not used, Chemical analyses of ground water and TDS concentrations estimated from borehole geophysical log data (resistivity-porosity and static spontaneous potential methods) were used to establish areas where TDS concentrations in ground water are less than or greater than 10,000 mg/l. The concentrations of TDS of water from the Silurian and Devonian carbonates were generally found to increase in a consistent trend downdip with depth into the Illinois and Michigan Basins; however, this trend was not observed in several anomalous areas where the 10,000 mg/l TDS boundary becomes more irregular in shape, There are also areas where the underlying Silurian carbonates have TDS concentrations that are less saline than the overlying Devonian carbonates. These anomalous areas may be the result of nonuniform recharge during Pleistocene time or more recent times, or from differences in permeability that control flow paths and rates. C1 US GEOL SURVEY,ITHACA,NY 14850. INDIANA UNIV,DEPT GEOL,BLOOMINGTON,IN 47401. RP SCHNOEBELEN, DJ (reprint author), US GEOL SURVEY,400 S CLINTON ST,IOWA CITY,IA 52240, USA. NR 27 TC 4 Z9 5 U1 1 U2 3 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1995 VL 33 IS 6 BP 965 EP 976 DI 10.1111/j.1745-6584.1995.tb00042.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TD127 UT WOS:A1995TD12700012 ER PT J AU BREWSTER, ML ANNAN, AP GREENHOUSE, JP KUEPER, BH OLHOEFT, GR REDMAN, JD SANDER, KA AF BREWSTER, ML ANNAN, AP GREENHOUSE, JP KUEPER, BH OLHOEFT, GR REDMAN, JD SANDER, KA TI OBSERVED MIGRATION OF A CONTROLLED DNAPL RELEASE BY GEOPHYSICAL METHODS SO GROUND WATER LA English DT Article ID NATURAL GRADIENT EXPERIMENT; SOLUTE TRANSPORT; SAND AQUIFER; FIELD EXPERIMENT; POROUS-MEDIA; TETRACHLOROETHYLENE; CONTAMINATION; DISPERSION; BEHAVIOR AB Seven hundred seventy liters of a dense nonaqueous phase liquid (DNAPL), tetrachloroethylene (PCE), were released into an isolated volume of a completely saturated natural sandy aquifer. The release was monitored over a period of 984 hours with a variety of geophysical methods including ground penetrating radar, time domain reflectometry, in situ resistivity, and a neutron soil moisture probe. The PCE formed a pool on a low permeability layer at approximately 1 m depth and spread over an area exceeding 32 m(2). In its course of downward migration, the PCE subsequently formed eight smaller pools. At the end of the experiment an estimated 41 percent of the total PCE volume remained trapped in the upper pool. The PCE mass and its spatial moments were calculated from radar reflection amplitudes. Between 48 and 100 percent of the PCE mass was accounted for by radar measurements. The center of mass moved a total of 0.5 m south southeast and 1.3 m downward. Spatial variances showed that the greatest lateral spreading occurred in the east-west direction. The results demonstrate that natural heterogeneities, even in a relatively homogeneous aquifer, can cause DNAPLs to spread laterally over large areas in the subsurface. This experiment also demonstrated that while the ability of geophysics to uniquely measure the presence of DNAPL is limited, certain techniques are well-suited to monitoring changes in DNAPL saturation. C1 KOMEX INT LTD,CALGARY,AB T3B 0M6,CANADA. QUEENS UNIV,DEPT CIVIL ENGN,KINGSTON,ON K7L 3N6,CANADA. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. COLORADO SCH MINES,GOLDEN,CO 80401. RP BREWSTER, ML (reprint author), UNIV WATERLOO,WATERLOO CTR GROUNDWATER RES,WATERLOO,ON N2L 3G1,CANADA. NR 24 TC 100 Z9 102 U1 2 U2 25 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1995 VL 33 IS 6 BP 977 EP 987 DI 10.1111/j.1745-6584.1995.tb00043.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TD127 UT WOS:A1995TD12700013 ER PT J AU ECKHARDT, DAV STACKELBERG, PE AF ECKHARDT, DAV STACKELBERG, PE TI RELATION OF GROUNDWATER QUALITY TO LAND-USE ON LONG-ISLAND, NEW-YORK SO GROUND WATER LA English DT Article ID COUNTY AB Water-quality data from 90 monitoring wells screened within 50 feet of the water table in the unconfined upper glacial aquifer beneath five areas of differing land use in Nassau and Suffolk Counties, Long Island, were compared to assess the effects of land use on ground-water quality. The areas, which range from 22 to 44 square miles, represent suburban land sewered more than 22 years at the time of the study (long-term sewered), suburban land sewered less than 8 years (recently sewered), suburban land without a regional sewer system, agricultural land, and undeveloped (forested) land. Comparison of water-quality data from the 90 wells indicated that samples from the undeveloped area had the lowest and smallest range in concentrations of several human-derived constituents, such as nitrate, alkalinity, boron, synthetic solvents, and pesticides. Concentrations of these constituents in samples from the three suburban areas and the agricultural area generally were intermediate to high and had the widest variation. Maximum-likelihood logistic regression analysis of explanatory variables that characterize the type of land use and population density within a 1/2-mile radius of each of the 90 wells was used to develop predictive equations for contaminant occurrence in ground water within 50 feet of the water table. Two logistic regression equations for the 90 monitoring wells were compared with equations developed independently from ground-water quality data at more than 240 other wells throughout Nassau and Suffolk Counties to evaluate the predictive value of the land-use variables at the larger two-county scale. The results demonstrate that the population density and amount of agricultural, commercial, and high- and medium-density residential land within specified areas around wells can be reliable predictors of contaminant presence. The strength of the correlations supports the premise that land use affects the quality of water in water-table aquifers overlain by highly permeable material because land use commonly determines the types and amounts of chemicals introduced at land surface. When coupled with GIS technology and accurate, detailed land-use and water-quality information, the methods and results of this study can be useful to local planning boards in evaluation of potential effects of development on ground-water quality. The methods can also be useful to hydrologists in the analysis and design of ground-water-monitoring networks. C1 US GEOL SURVEY,W TRENTON,NJ 08628. RP ECKHARDT, DAV (reprint author), US GEOL SURVEY,903 HANSHAW RD,ITHACA,NY 14850, USA. NR 35 TC 95 Z9 98 U1 1 U2 10 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1995 VL 33 IS 6 BP 1019 EP 1033 DI 10.1111/j.1745-6584.1995.tb00047.x PG 15 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TD127 UT WOS:A1995TD12700017 ER PT J AU EARLY, PJ LANDA, ER AF EARLY, PJ LANDA, ER TI USE OF THERAPEUTIC RADIONUCLIDES IN MEDICINE SO HEALTH PHYSICS LA English DT Article DE RADIATION, MEDICAL; RADIATION THERAPY; HISTORICAL PROFILES; NUCLEAR MEDICINE ID BONE AB The purpose of this paper is to follow the course of historical development in the use of radiopharmaceuticals as a therapeutic tool in nuclear medicine. This chapter is designed to point out the different phases of the development of therapeutic nuclear medicine, pointing out the events which most shaped its history along the way. Those events included the discovery of radioactivity, the development of the cyclotron and nuclear reactor as a method of delivering high specific activity radioactive sources, and a few significant therapeutic radionuclides such as I-131 and P-32. The most significant therapeutic radionuclide was radium, which is treated very extensively in this paper from an historical viewpoint. It is only recently that attention of the nuclear medicine community turned to new therapeutic agents, such as bone pain palliation agents, monoclonal antibodies, and others. It may be that the next growth phase of nuclear medicine will revolve around therapy with these radionuclides. C1 US GEOL SURVEY, DIV WATER RESOURCES, RESTON, VA 22092 USA. RP EARLY, PJ (reprint author), ASSOCIATES MED PHYS, LLC, 5284 TRANSPORTAT BLVD, CLEVELAND, OH 44125 USA. NR 50 TC 9 Z9 10 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD NOV PY 1995 VL 69 IS 5 BP 677 EP 694 DI 10.1097/00004032-199511000-00005 PG 18 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA TA722 UT WOS:A1995TA72200006 PM 7558861 ER PT J AU Nichols, DJ AF Nichols, DJ TI The role of palynology in paleoecological analyses of Tertiary coals SO INTERNATIONAL JOURNAL OF COAL GEOLOGY LA English DT Article AB Pollen, spores, and other plant microfossils are important constituents of Tertiary coals, both as petrographic components (the maceral sporinite) and as distinctive indicators of the nature of the depositional environment in which the coal-forming Feat accumulated. Palynological analyses, which have been conducted on Tertiary coals since the 1930's, play an increasingly important role in modem paleoecological analyses of coals. Among the most important factors controlling the petrographic composition and facies characteristics of coal deposits are the types and relative abundances of plants that composed the peat. At present, wetland environments in which peat accumulates (mires) range from marshes and bogs to forested swamps; each is inhabited by distinctive plant communities. These plant communities are associated with varied conditions of climate, water depth, chemistry, and nutrient supply, and the floras can be indicative of these conditions. In the Tertiary Period, plant communities of mires were also highly diverse and specialized (especially as compared with those of the Carboniferous). The dominant species in some Paleocene mire floras were gymnosperms, but continuing a trend begun in Late Cretaceous time, angiosperms became increasingly prominent through the Tertiary. The diverse angiosperm-dominated mire floras produced coals that vary significantly in facies and hence in quality. Such contrasts are evident in contemporaneous coals from different paleolatitudes, as well as among coals of different ages within the Tertiary, as exemplified by selected deposits in the western United States. The palynofloras of these coals reflect the floristic composition of the plant communities of the ancient mires. RP Nichols, DJ (reprint author), US GEOL SURVEY,MS 919,BOX 25046,DENVER,CO 80225, USA. NR 20 TC 13 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-5162 J9 INT J COAL GEOL JI Int. J. Coal Geol. PD NOV PY 1995 VL 28 IS 2-4 BP 139 EP 159 DI 10.1016/0166-5162(95)00017-8 PG 21 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA TM703 UT WOS:A1995TM70300005 ER PT J AU Warwick, PD Hook, RW AF Warwick, PD Hook, RW TI Petrography, geochemistry, and depositional setting of the San Pedro and Santo Tomas coal zones: Anomalous algae-rich coals in the middle part of the Claiborne Group (Eocene) of Webb County, Texas SO INTERNATIONAL JOURNAL OF COAL GEOLOGY LA English DT Article ID MISSISSIPPI DELTA; BASIN AB Two coal zones, the San Pedro and the overlying Santo Tomas, are present for nearly 35 km in outcrop, surface and underground mines, and shallow drill holes along the strike of the middle part of the Claiborne Group (Eocene) in Webb County, Texas. A sandstone-dominated interval of 25 to 35 m separates the two coal zones, which range up to 3 m in thickness. Each coal zone contains carbonaceous shales, thin (<0.75 m) impure coal beds, and thin (<0.85 m) but commercially significant nonbanded coal beds. The nonbanded coals are different from other Tertiary coals of the Gulf of Mexico Coastal Plain: unlike lignites that are typical of the older Wilcox Group (Paleocene-Eocene) and younger Jackson Group (Eocene), nonbanded coals of the Claiborne Group have high vitrinite-reflectance values (0.53 R(max)) and high calorific yields (average 6670) kcal/kg or 12,000 Btu, dry basis). The coals are weakly agglomerating (free-swelling index is 1.5-2.0) and have an apparent rank of high-volatile bituminous. The coal-bearing portion of the middle Claiborne Group in the Rio Grande area represents a fining-upward transition from sandstone-dominated, marine-influenced, lower delta plain depositional environments to more inland, mudstone-rich, predominantly freshwater deltaic settings. Discontinuities within the San Pedro coal zone are attributed mainly to the influence of contemporaneous deposition of distributary mouth-bar sand bodies. The less variable nature of the Santo Tomas coal zone reflects its origin in the upper part of an interlobe basin that received only minor elastic influx. Petrographic attributes of the nonbanded coals indicate that they formed subaqueously in fresh to possibly brackish waters. A highly degraded groundmass composed of eugelinite is the main petrographic component (approximately 71%, mineral-matter-free basis), An enriched liptinite fraction (approximately 23%) probably accounts for unusually high calorific values. There is negligible inertinite. Petrographic study of polished blocks indicates that approximately 10 percent of the nonbanded coal from both coal zones is composed of green algae fructifications, which also occur in clastic rocks of the coal-bearing interval. Such algal material cannot be identified or quantified by conventional coal petrographic techniques that utilize particle pellets or by palynological analyses that include acid preparation. C1 UNIV TEXAS,PALEONTOL VERTEBRES LAB,AUSTIN,TX 78712. RP Warwick, PD (reprint author), US GEOL SURVEY,NATL CTR MS 956,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. OI Warwick, Peter/0000-0002-3152-7783 NR 63 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-5162 J9 INT J COAL GEOL JI Int. J. Coal Geol. PD NOV PY 1995 VL 28 IS 2-4 BP 303 EP 342 DI 10.1016/0166-5162(95)00022-4 PG 40 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA TM703 UT WOS:A1995TM70300010 ER PT J AU GARBER, MJ DEYONGE, KG BYATT, JC LELLIS, WA HONEYFIELD, DC BULL, RC SCHELLING, GT ROEDER, RA AF GARBER, MJ DEYONGE, KG BYATT, JC LELLIS, WA HONEYFIELD, DC BULL, RC SCHELLING, GT ROEDER, RA TI DOES-RESPONSE EFFECTS OF RECOMBINANT BOVINE SOMATOTROPIN (POSILAC(TM)) ON GROWTH-PERFORMANCE AND BODY-COMPOSITION OF 2-YEAR-OLD RAINBOW-TROUT (ONCORHYNCHUS-MYKISS) SO JOURNAL OF ANIMAL SCIENCE LA English DT Article DE SOMATOTROPIN; RAINBOW TROUT; GROWTH ID PORCINE SOMATOTROPIN; SALMO-GAIRDNERI; MUSCLE COMPOSITION; DOSE-RESPONSE; HORMONE; KISUTCH; STEERS; PIGS AB Two hundred rainbow trout (Oncorhynchus mykiss, mean weight 301.5 g) were allotted to four treatments with five replicates in a randomized block design to determine the dose-response effects of recombinant bovine somatotropin (rbST; Posilac(TM)) on growth performance and carcass composition. Treatments were sham-injected controls (S), 10 mu g/g BW of rbST (L), 20 mu g/g BW of rbST (M), and 30 mu g/g BW of rbST (H). The tanks held 135 L; water flow = 15.1 L/min; temperature = 15 degrees C. The fish were maintained in a 12-h light:dark cycle and hand-fed twice daily. The fish received a single intraperitoneal (i.p.) injection on d 0 and were weighed on d 0, 14, 28, and 56. On d 56 the fish were killed. The whole body (WBW), eviscerated carcass (EC), viscera (VIS), and reproductive organ weights and the increase in average daily body length (ADL) were determined. Recombinant bST reduced (linear, P < .004) feed intake 17.6% from d 0 to 14 and improved ADG 44.8% from d 0 to 14 (linear, P < .001) and 8.1% from d 0 to 56 (linear, P < .022). Treated groups had improved (linear, P < .001) feed efficiencies for d 0 to 28. Treatment with rbST increased final weight (linear, P < .018) and length (linear, P < .001), decreased carcass dry matter (linear, P < .001) and fat(linear, P < .001), content, increased carcass ash (linear, P < .001) and tended to increase carcass protein (linear, P < .054) content. Recombinant bST increased WBW (linear, P < .018) and EC (linear, P < .003) but decreased (linear, P < .015) testes weight. Ovary weights, VIS and overall gonadosomatic index were unaffected (P > .05) by rbST. Recombinant bST was undetectable in serum samples taken on d 56 as determined by radioimmunoassay. Overall, the improved ADG, feed efficiency, body mass, and composition indicate that administration of rbST to rainbow trout may be an efficacious method of modulating growth in fish. C1 UNIV IDAHO,DEPT VET & ANIM SCI,MOSCOW,ID 83844. US FISH & WILDLIFE SERV,HAGERMAN,ID 83332. MONSANTO AGR CO,ST LOUIS,MO 63198. NR 30 TC 30 Z9 33 U1 1 U2 3 PU AMER SOC ANIMAL SCIENCE PI SAVOY PA 1111 NORTH DUNLAP AVE, SAVOY, IL 61874 SN 0021-8812 J9 J ANIM SCI JI J. Anim. Sci. PD NOV PY 1995 VL 73 IS 11 BP 3216 EP 3222 PG 7 WC Agriculture, Dairy & Animal Science SC Agriculture GA TF715 UT WOS:A1995TF71500004 PM 8586575 ER PT J AU KOLPIN, DW GOOLSBY, DA THURMAN, EM AF KOLPIN, DW GOOLSBY, DA THURMAN, EM TI PESTICIDES IN NEAR-SURFACE AQUIFERS - AN ASSESSMENT USING HIGHLY SENSITIVE ANALYTICAL METHODS AND TRITIUM SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; UNITED-STATES; GROUND-WATER; HERBICIDES; CONTAMINATION AB In 1992, the U.S. Geological Survey (USGS) determined the distribution of pesticides in near-surface aquifers of the midwestern USA to be much more widespread than originally determined during a 1991 USGS study. The frequency of pesticide detection increased from 28.4% during the 1991 study to 59.0% during the 1992 study. This increase in pesticide detection was primarily the result of a more sensitive analytical method that used reporting limits as much as 20 times lower than previously available and a threefold increase in the number of pesticide metabolites analyzed. No pesticide concentrations exceeded the U.S. Environmental Protection Agency's (USEPAs) maximum contaminant levels or health advisory levels for drinking water. However, five of the six most frequently detected compounds during 1999 were pesticide metabolites that currently do not have drinking water standards determined. The frequent presence of pesticide metabolites for this study documents the importance of obtaining information on these compounds to understand the fate and transport of pesticides in the hydrologic system, It appears that the 56 parent compounds analyzed follow similar pathways through the hydrologic system as atrazine. When atrazine was detected by routine or sensitive analytical methods, there was an increased likelihood of detecting additional parent compounds. As expected, the frequency of pesticide detection was highly dependent on the analytical reporting limit. The number of atrazine detections more than doubled as the reporting limit decreased from 0.10 to 0.01 mu g/L. The 1992 data provided no indication that the frequency of pesticide detection would level off as improved analytical methods provide concentrations below 0.003 mu g/L. A relation was determined between groundwater age and the frequency of pesticide detection, with 15.8% of the samples composed of pre-1953 water and 70.3% of the samples of post-1953 water having a detection of at least one pesticide or metabolite, Pre-1953 water is less likely to contain pesticides because it tends to predate the use of pesticides to increase crop production in the Midwest, Pre-1953 water was more likely to occur in the near-surface bedrock aquifers (50.0%) than in the near-surface unconsolidated aquifers (9.1%) sampled. C1 US GEOL SURVEY,DFC,DENVER,CO 80225. US GEOL SURVEY,LAWRENCE,KS 66049. RP KOLPIN, DW (reprint author), US GEOL SURVEY,400 S CLINTON ST,IOWA CITY,IA 52244, USA. RI Thurman, Earl/B-5131-2011 NR 30 TC 76 Z9 76 U1 1 U2 7 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD NOV-DEC PY 1995 VL 24 IS 6 BP 1125 EP 1132 PG 8 WC Environmental Sciences SC Environmental Sciences & Ecology GA TF758 UT WOS:A1995TF75800010 ER PT J AU WILLIAMS, MW YANG, DQ LIU, FJ TURK, J MELACK, JM AF WILLIAMS, MW YANG, DQ LIU, FJ TURK, J MELACK, JM TI CONTROLS ON THE MAJOR ION CHEMISTRY OF THE URUMQI-RIVER, TIAN-SHAN, PEOPLES-REPUBLIC-OF-CHINA SO JOURNAL OF HYDROLOGY LA English DT Article ID SIERRA-NEVADA; ALPINE BASIN; ACID-RAIN; SULFUR; NEUTRALIZATION; PRECIPITATION; GROUNDWATER; COLORADO; RUNOFF; WATER AB Water and snow samples were collected in May of 1990 and 1992 in headwater basins and along a longitudinal transect of the Urumqi River, located in northwestern China. Surface waters were dominated by Ca2+ and HCO3- at all sites. Maximum measured SO42- concentrations in surface waters were 550 mu eq L(-1), and were balanced by Ca2+ and HCO3-; pH was slightly alkaline at all locations, Several independent analyses each concluded that the solute composition of surface waters was dominated by dissolution of rocks with rapid weathering kinetics, such as calcite and dolomite, Preliminary analysis of stable sulfur ratios in headwater basins shows delta(34)S values of +6.8 for snow and +3.3 for surface waters. Changes in the delta(34)S value of surface waters with increasing basin area were variable, suggesting changes in the stable sulfur ratios of source materials. The large amounts of HCO3- and base cations at all sites indicates that the Urumqi River is not sensitive to acidification from atmospheric deposition. C1 UNIV COLORADO,INST ARTIC & ALPINE RES,BOULDER,CO 80309. LANZHOU INST GLACIOL & GEOCRYOL,LANZHOU 730000,PEOPLES R CHINA. US GEOL SURVEY,DIV WATER RESOURCES,DENVER,CO 80225. UNIV CALIF SANTA BARBARA,DEPT BIOL SCI,SANTA BARBARA,CA 93106. RP WILLIAMS, MW (reprint author), UNIV COLORADO,DEPT GEOG,BOULDER,CO 80309, USA. NR 39 TC 14 Z9 28 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD NOV PY 1995 VL 172 IS 1-4 BP 209 EP 229 PG 21 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA TE183 UT WOS:A1995TE18300013 ER PT J AU SCHWALB, A LOCKE, SM DEAN, WE AF SCHWALB, A LOCKE, SM DEAN, WE TI OSTRACODE DELTA-O-18 AND DELTA-C-13 EVIDENCE OF HOLOCENE ENVIRONMENTAL-CHANGES IN THE SEDIMENTS OF 2 MINNESOTA LAKES SO JOURNAL OF PALEOLIMNOLOGY LA English DT Article; Proceedings Paper CT 1994 Meeting of the American-Quaternary-Association CY JUN 19-22, 1994 CL UNIV MINNESOTA, MINNEAPOLIS, MN SP Amer Quaternary Assoc HO UNIV MINNESOTA DE MIDWESTERN UNITES STATES; STABLE ISOTOPES; OSTRACODES; HOLOCENE; PALEOCLIMATE; LAKE ID VEGETATION; CARBONATES; OXYGEN; RATIOS; IRON AB Stable oxygen and carbon isotope geochemistry of ostracode valves, abundance and assemblages of ostracode species, and sedimentological parameters from cores taken in Williams and Shingobee Lakes in north-central Minnesota show changes in climatic and hydrologic history during the Holocene. Isotopic records are consistent with the following scenario: Before 9800 yr B.P. the two lakes were connected. Increasing evaporation through the jack/red pine period (9800-7700 yr B.P.) led to lower lake levels, leaving small separated basins. The prairie period (7700-4000 yr B.P.) reflects high aridity, and lake levels reached low stands shortly before 6500 yr B.P. Low lake levels are associated with groundwater discharge between 6500 and 6000 yr B.P. The hardwood period (4000-3200 yr B.P.) corresponds to long cold winters and warm to cool summers with lower evaporation rates and slower sedimentation. During the white pine period (<3200 yr B.P.) evaporation increased and/or precipitation shifted to the summer months. These changes can be related to shifting atmospheric circulation patterns. Zonal flow was probably dominant during the early Holocene until the end of the prairie period (c. 4000 yr B.P.). During the hardwood period a combination of zonal and meridional flow patterns caused long and cold winters and wetter summers. During the white pine period winters were shorter and the meridional flow pattern more significant. Today meridional flow dominates the circulation pattern. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP SCHWALB, A (reprint author), UNIV MINNESOTA,LIMNOL RES CTR,220 PILLSBURY HALL,310 PILLSBURY DR SE,MINNEAPOLIS,MN 55455, USA. NR 46 TC 38 Z9 40 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-2728 J9 J PALEOLIMNOL JI J. Paleolimn. PD NOV PY 1995 VL 14 IS 3 BP 281 EP 296 DI 10.1007/BF00682429 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Limnology SC Environmental Sciences & Ecology; Geology; Marine & Freshwater Biology GA TD951 UT WOS:A1995TD95100006 ER PT J AU Baedecker, PA Grossman, JN AF Baedecker, PA Grossman, JN TI The SPECTRA program library: A PC based system for gamma-ray spectra analysis and INAA data reduction SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article AB A PC based system has been developed for the analysis of gamma-ray spectra and for the complete reduction of data from INAA experiments, including software to average the results from multiple lines and multiple countings and to produce a final report of analysis. Graphics algorithms may be called for the analysis of complex spectral features, to compare the data from alternate photopeaks and to evaluate detector performance during a given counting cycle. A database of results for control samples can be used to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. The entire software library can be accessed through a user-friendly menu interface with internal help. RP Baedecker, PA (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD NOV PY 1995 VL 198 IS 1 BP 55 EP 68 DI 10.1007/BF02038245 PG 14 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA TL238 UT WOS:A1995TL23800006 ER PT J AU PERALTA, RC CANTILLER, RRA TERRY, JE AF PERALTA, RC CANTILLER, RRA TERRY, JE TI OPTIMAL LARGE-SCALE CONJUNCTIVE WATER-USE PLANNING - CASE-STUDY SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID SUSTAINED GROUNDWATER YIELD; OPTIMIZATION MODEL; AQUIFER SYSTEMS; STEADY-STATE; MANAGEMENT AB Optimal sustained ground-water yield and conjunctive water-use strategies are presented for northeastern Arkansas, based on water demands projected for the five decades of 1990-2039. Each strategy consists of spatially and temporally distributed values of ground-water and surface-water use. The 33,700 km(2) region has much irrigation and is very dependent upon ground water. Ground-water flow simulation/optimization (S/O) models are used to attempt to satisfy temporally increasing water needs for alternative future management scenarios. The S/O models employ a sequential steady-state embedding approach, and contain over 1,600 embedded ground-water and river-volume balance constraints per decade (stage). C1 UNIV ARKANSAS,DEPT BIOL & AGR ENGN,FAYETTEVILLE,AR 72701. UNIV ARKANSAS,DEPT AGR & BIOL ENGN,FAYETTEVILLE,AR 72701. US GEOL SURVEY,WRD,LITTLE ROCK,AR 72201. RP PERALTA, RC (reprint author), UTAH STATE UNIV,DEPT BIOL & IRRIG ENGRG,LOGAN,UT 84322, USA. NR 33 TC 43 Z9 43 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD NOV-DEC PY 1995 VL 121 IS 6 BP 471 EP 478 DI 10.1061/(ASCE)0733-9496(1995)121:6(471) PG 8 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA TA123 UT WOS:A1995TA12300010 ER PT J AU Cloern, JE Grenz, C VidergarLucas, L AF Cloern, JE Grenz, C VidergarLucas, L TI An empirical model of the phytoplankton chlorophyll:carbon ratio - The conversion factor between productivity and growth rate SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID LEPTOCYLINDRUS-DANICUS CLEVE; STEADY-STATE DESCRIPTION; LIGHT-LIMITED GROWTH; MARINE-PHYTOPLANKTON; SKELETONEMA-COSTATUM; CONTINUOUS CULTURE; A-RATIO; IRRADIANCE; PHOTOSYNTHESIS; TEMPERATURE AB We present an empirical model that describes the ratio of phytoplankton chlorophyll a to carbon, Chl: C, as a function of temperature, daily irradiance, and nutrient-limited growth rate. Our model is based on 219 published measurements of algal cultures exposed to light-limited or nutrient-limited growth conditions. We illustrate an approach for using this estimator of Chl:C to calculate phytoplankton population growth rate from measured primary productivity. This adaptive Chl:C model gives rise to interactive light-nutrient effects in which growth efficiency increases with nutrient availability under low-light conditions. One implication of this interaction is the enhancement of phytoplankton growth efficiency, in addition to enhancement of biomass yield, as a response to eutrophication. C1 UNIV AIX MARSEILLE 2, CTR OCEANOL MARSEILLE, F-13007 MARSEILLE, FRANCE. STANFORD UNIV, DEPT CIVIL ENGN, STANFORD, CA 94305 USA. RP Cloern, JE (reprint author), US GEOL SURVEY, MS 496, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. RI Cloern, James/C-1499-2011; GRENZ, Christian/F-7586-2011; GRENZ, Christian/I-7830-2012; OI GRENZ, Christian/0000-0002-6922-9124; Cloern, James/0000-0002-5880-6862 NR 30 TC 273 Z9 276 U1 6 U2 52 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1995 VL 40 IS 7 BP 1313 EP 1321 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA TK469 UT WOS:A1995TK46900015 ER PT J AU HEQUETTE, A DESROSIERS, M BARNES, PW AF HEQUETTE, A DESROSIERS, M BARNES, PW TI SEA-ICE SCOURING ON THE INNER SHELF OF THE SOUTHEASTERN CANADIAN-BEAUFORT-SEA SO MARINE GEOLOGY LA English DT Article ID SEDIMENT TRANSPORT; SHOREFACE; ALASKA; BEACH AB About 2200 ice scours were observed and analyzed over a distance of approximately 500 km on the inner shelf of the southeastern Canadian Beaufort Sea. Ice scours were divided into two types based on their morphology: multiple scours consisting of a series of parallel scours and ridges, and single scours. Single scours are the dominant type representing more than 85% of the total observations. The mean scour depth and width are 0.3 m and 11 m respectively, but scour depths of more than 2 m and a scour width up to 345 m were documented. The magnitude of ice scouring processes increases with water depth. In water depths less than 10 m, less than 25% of the seafloor surface is reworked by ice scours. This percentage increases significantly seaward of the 10 m isobath, being more than 75% in water depths in excess of 12 m. A break in the seabed slope at about 10 to 12 m water depth marks a boundary between a nearshore zone moderately influenced by ice processes and an outer zone affected by intense ice scouring. This morphological boundary could be due to intense erosion by the keels of pressure ice ridges at the inner edge of a zone of grounded ice ridges. Most of the observed ice scours appear to be reworked, especially in water depths of less than 10 m, and represent small-scale sediment sinks. Inshore of the 10 m isobath, scour reworking is believed to be mainly due to frequent bottom disturbance by wave orbital currents and mean near-bottom flows during the open water season. Scour orientations show that the dominant motion of ice during scouring events is east or west, which is subparallel to the bathymetric contours and coastline. Scour terminal push mounds, however, suggest a dominant east to southeast movement that may contribute to onshore sediment transport during ice push events. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP HEQUETTE, A (reprint author), UNIV LAVAL,CTR ETUD NORD,ST FOY,PQ G1K 7P4,CANADA. NR 48 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD NOV PY 1995 VL 128 IS 3-4 BP 201 EP 219 DI 10.1016/0025-3227(95)00095-G PG 19 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA TG119 UT WOS:A1995TG11900006 ER PT J AU Lidz, BH AF Lidz, BH TI A tribute to Cesare Emiliani - Eminent scholar, professor, and friend - Obituary SO MARINE MICROPALEONTOLOGY LA English DT Item About an Individual RP Lidz, BH (reprint author), US GEOL SURVEY,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD NOV PY 1995 VL 25 IS 4 BP 219 EP 220 DI 10.1016/0377-8398(95)90000-4 PG 2 WC Paleontology SC Paleontology GA TN263 UT WOS:A1995TN26300001 ER PT J AU Lidz, BH McNeill, DF AF Lidz, BH McNeill, DF TI Reworked paleogene to early Neogene planktic foraminifera: Implications of an intriguing distribution at a late Neogene prograding margin, Bahamas SO MARINE MICROPALEONTOLOGY LA English DT Article ID RIO-GRANDE RISE; CARBONATE PLATFORMS; SOUTH-ATLANTIC; SEA; TERTIARY; BANK; SEDIMENTS; EVOLUTION; HIATUSES; MEXICO AB A rich, uniquely distributed assemblage (> 80 species) of reworked Paleogene to early Neogene (similar to 66 - 15 Ma) planktic foraminifera is documented within > 470 m of late Neogene (similar to 5.7-1.6 Ma) borehole limestone from the Great Bahama Bank west margin. Tests vary in size from 0.13 to 1.0 mm and are unusually well preserved. Where obtainable from the rock, the relict species constitute an estimated 20% to 50% of all taxa. Paleocene faunas occur in upper Miocene host rocks, Eocene species occur in upper Miocene and basal upper Pliocene rocks, and mixed Oligocene and early Miocene taxa occur throughout the section, including the uppermost Pliocene (i.e., the oldest groups disappear successively uphole). Each host-rock interval is separated by major disconformities. This record provides a substantial proxy for: (1) a probable source feature (an epipelagic marine tectonic wall, escarpment, or outcrop composed of pelagic and hemipelagic sediments); (2) a probable tectonically active source area (northern Cuba or southern Bahamas); and (3) a variety of events that span > 60 Myr and have wide-ranging implications, from local (progressive isolation of the oldest faunas), to regional (changes in water depth indicated by the faunas), to global (hiatuses that correlate with one or more major sequence boundaries in the Atlantic, Bahamas, and Gulf of Mexico, as well as proposed eustatic lowstands). Seven unidentified foraminiferal biozones correspond to a proposed early Eocene composite condensed section on the eustatic curve and may have regional implications. The relict faunas also have significant implications for the timing and types of Paleogene and early Neogene sedimentation or nondeposition, sea-level fluctuations, slumping or changing depth of effective marine erosion, and regional late Neogene events that occurred over 4 Myr (age of host rocks). The direction of the source area from the secondary-emplacement site and the estimated percentages of relict faunas indicate that not all the microfossils in the late Neogene borehole sediments and, by extrapolation therefore, along the entire west margin of the platform, were locally derived. The amount of a possible attendant sedimentary component is not known. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. RP Lidz, BH (reprint author), US GEOL SURVEY,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 82 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD NOV PY 1995 VL 25 IS 4 BP 221 EP 268 DI 10.1016/0377-8398(96)80993-5 PG 48 WC Paleontology SC Paleontology GA TN263 UT WOS:A1995TN26300002 ER PT J AU Kvenvolden, KA AF Kvenvolden, KA TI A review of the geochemistry of methane in natural gas hydrate SO ORGANIC GEOCHEMISTRY LA English DT Review DE gas hydrate; methane; hydrocarbon gases; carbon-isotopic composition; microbial; thermal ID DRILLING PROJECT LEG-76; BLAKE OUTER RIDGE; NORTH SLOPE; SEA; MEXICO; GULF; SEDIMENTS; SEEPAGE; MARINE; ALASKA AB The largest accumulations on Earth of natural gas are in the form of gas hydrate, found mainly offshore in outer continental margin sediment and, to a lesser extent, in polar regions commonly associated with permafrost. Measurements of hydrocarbon gas compositions and of carbon-isotopic compositions of methane from natural gas hydrate samples, collected in subaquatic settings from around the world, suggest that methane guest molecules in the water clathrate structures are mainly derived by the microbial reduction of CO2 from Sedimentary organic matter. Typically, these hydrocarbon gases are composed of >99% methane, with carbon-isotopic compositions (delta(13)C(PDB)) ranging from -57 to -73 parts per thousand. In only two regions, the Gulf of Mexico and the Caspian Sea, has mainly thermogenic methane been found in gas hydrate. There, hydrocarbon gases have methane contents ranging from 21 to 97%, with delta(13)C values ranging from -29 to -57 parts per thousand. At a few locations, where the gas hydrate contains a mixture of microbial and thermal methane, microbial methane is always dominant. Continental: gas hydrate, identified in Alaska and Russia, also has hydrocarbon gases composed of >99% methane, with carbon-isotopic compositions ranging from -41 to -49 parts per thousand. These gas hydrate deposits also contain a mixture of microbial and thermal methane, with thermal methane likely to be dominant. Published by Elsevier Science Ltd RP Kvenvolden, KA (reprint author), US GEOL SURVEY,WESTERN MARINE & COASTAL GEOL SURVEYS TEAM,345 MIDDLEFIELD RD,M-S 999,MENLO PK,CA 94025, USA. NR 52 TC 190 Z9 263 U1 17 U2 90 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD NOV-DEC PY 1995 VL 23 IS 11-12 BP 997 EP 1008 DI 10.1016/0146-6380(96)00002-2 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ412 UT WOS:A1995UQ41200001 ER PT J AU FRIEDLY, JC DAVIS, JA KENT, DB AF FRIEDLY, JC DAVIS, JA KENT, DB TI MODELING HEXAVALENT CHROMIUM SEDUCTION IN GROUNDWATER IN FIELD-SCALE TRANSPORT AND LABORATORY BATCH EXPERIMENTS SO WATER RESOURCES RESEARCH LA English DT Article ID GRADIENT TRACER TEST; SOLUTE TRANSPORT; ORGANIC SOLUTES; MASS-TRANSFER; POROUS-MEDIA; CAPE-COD; SAND AQUIFER; GRAVEL; MASSACHUSETTS; NONEQUILIBRIUM AB A plausible and consistent model is developed to obtain a quantitative description of the gradual disappearance of hexavalent chromium (Cr(VI)) from groundwater in a small-scale field tracer test and in batch kinetic experiments using aquifer Sediments under similar chemical conditions. The data exhibit three distinct timescales. Fast reduction occurs in well-stirred batch reactors in times much less than 1 hour and is followed by slow reduction over a timescale of the order of 2 days. In the field, reduction occurs on a timescale of the order of 8 days. The model is based on the following hypotheses. The chemical reduction reaction occurs very fast, and the longer timescales are caused by diffusion resistance, Diffusion into the secondary porosity of grains causes the apparent slow reduction rate in batch experiments. In the model of the field experiments, the reducing agent, heavy Fe(II)-bearing minerals, is heterogeneously distributed in thin strata located between larger nonreducing sand lenses that comprise the bulk of the aquifer solids. It is found that reducing strata of the order of centimeters thick are sufficient to contribute enough diffusion resistance to cause the observed longest timescale in the field. A one-dimensional advection/dispersion model is formulated that describes the major experimental trends. Diffusion rates are estimated in terms of an elementary physical picture of flow through a stratified medium containing identically sized spherical grains. Both reduction and sorption reactions are included. Batch simulation results are sensitive to the fraction of reductant located at or near the surface of grains, which controls the amount of rapid reduction, and the secondary porosity, which controls the rate of slow reduction observed in batch experiments. Results of Cr(VI) transport simulations are sensitive to the thickness and relative size of the reducing stratum. Transport simulation results suggest that nearly all of the reductant must be located in the reducing stratum. Within this context and as long as there is adequate reductive capacity present, the transport simulation results are insensitive to the parameters important for the batch simulations. The results illustrate how a combination of field measurements and batch laboratory studies can be used to improve predictive modeling of contaminant transport. C1 US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. RP FRIEDLY, JC (reprint author), UNIV ROCHESTER,DEPT CHEM ENGN,ROCHESTER,NY 14627, USA. NR 43 TC 23 Z9 23 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1995 VL 31 IS 11 BP 2783 EP 2794 DI 10.1029/95WR02104 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TD805 UT WOS:A1995TD80500015 ER PT J AU CAMPBELL, DH CLOW, DW INGERSOLL, GP MAST, MA SPAHR, NE TURK, JT AF CAMPBELL, DH CLOW, DW INGERSOLL, GP MAST, MA SPAHR, NE TURK, JT TI PROCESSES CONTROLLING THE CHEMISTRY OF 2 SNOWMELT-DOMINATED STREAMS IN THE ROCKY-MOUNTAINS SO WATER RESOURCES RESEARCH LA English DT Article ID SIERRA-NEVADA; CALIFORNIA; COLORADO; SNOWPACK; FOREST; WATER; LAKE AB Time-intensive discharge and chemical data for two alpine streams in the Loch Vale watershed, Colorado, were used to identify sources of runoff, flow paths, and important biogeochemical processes during the 1992 snowmelt runoff season. In spite of the paucity of soil cover the chemical composition of the streams is regulated much as in typical forested watersheds. Soils and other shallow groundwater matrices such as boulder fields appear to be more important in controlling surface-water chemistry than their abundance would indicate. The chemical composition of the major source waters (usually thought of as end-members whose chemical composition is relatively constant over time) changes at the same time that their mixing ratio in streams changes, confounding use of end-member mixing models to describe stream-water chemistry. Changes in the chemical composition of these source waters are caused by the ionic pulse of solutes from the snowpack and the small size of the shallow groundwater reservoir compared to the volume of snowmelt passing through it. The brief hydrologic residence time in the shallow groundwater indicates that concentrations of most dissolved constituents of stream water were controlled by fast geochemical processes that occurred on timescales of hours to days, rather than slower processes such as weathering of primary minerals. Differences in the timing of snowmelt-related processes between different areas of the watershed also affect the stream-water chemical composition. Cirque lakes affect discharge and chemical composition of one of the streams; seasonal control on stream-water NO3 and SiO2 concentrations by diatom uptake in the lakes was inferred. Elution of acidic waters from the snowpack, along with dilution of base cations originating in shallow groundwater, caused episodes of decreased acid-neutralizing capacity in the streams, but the streams did not become acidic. RP CAMPBELL, DH (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,MAIL STOP 415,LAKEWOOD,CO 80225, USA. NR 27 TC 130 Z9 131 U1 1 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1995 VL 31 IS 11 BP 2811 EP 2821 DI 10.1029/95WR02037 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TD805 UT WOS:A1995TD80500017 ER PT J AU REICHARD, EG AF REICHARD, EG TI GROUNDWATER-SURFACE WATER MANAGEMENT WITH STOCHASTIC SURFACE-WATER SUPPLIES - A SIMULATION OPTIMIZATION APPROACH SO WATER RESOURCES RESEARCH LA English DT Article ID STREAM-AQUIFER SYSTEM; CHANCE-CONSTRAINED MODEL; IRRIGATED AGRICULTURE; QUALITY MANAGEMENT; CONJUNCTIVE USE; UNCERTAINTY; REMEDIATION; DESIGN; INFORMATION; HYDRAULICS AB A new simulation optimization model for groundwater-surface water management identifies efficient strategies for meeting water demand and controlling a regional water quality problem, while accounting for varying availability of surface water supplies. Optimal values of model variables are computed for ranges of surface water availability. Expected groundwater levels are computed using a response function approach, which incorporates a probability for each hydraulic stress. Three objective functions are considered: (1) minimize need for supplemental water, (2) minimize imposed water use reductions, and (3) minimize changes from current pumping patterns. The model imposes constraints on expected groundwater levels, expected hydraulic gradients (surrogates for controlling contaminant transport), capacities of pipeline and recharge facilities, and water demand requirements. Capacity and demand constraints must be met every year for all possible surface water conditions. Application to the Santa Clara-Calleguas Basin in southern California indicates that a large quantity of supplemental water or significant pumpage reductions, particularly in the lower aquifer, may be required to control seawater intrusion with current facilities. Supplemental water would be delivered directly to users through pipelines and artificially recharged. Results also indicate that the current artificial-recharge program has been valuable and that construction of new artificial-recharge facilities might be beneficial. It should be noted that local agencies are currently developing several potential sources of supplemental water. Monte Carlo simulations yield estimates of the reliability of gradient constraints in controlling advective transport and the likelihood that water level constraints will be violated. RP REICHARD, EG (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,5735 KEARNY VILLA RD,SUITE O,SAN DIEGO,CA 92123, USA. NR 59 TC 58 Z9 59 U1 1 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1995 VL 31 IS 11 BP 2845 EP 2865 DI 10.1029/95WR02328 PG 21 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TD805 UT WOS:A1995TD80500020 ER PT J AU BAEHR, AL BAKER, RJ AF BAEHR, AL BAKER, RJ TI USE OF A REACTIVE GAS-TRANSPORT MODEL TO DETERMINE RATES OF HYDROCARBON BIODEGRADATION IN UNSATURATED POROUS-MEDIA SO WATER RESOURCES RESEARCH LA English DT Note ID GROUNDWATER; SAND AB A mathematical model is presented that simulates the transport and reaction of any number of gaseous phase constituents (e.g. CO2, O-2, N-2, and hydrocarbons) in unsaturated porous media. The model was developed as part of a method to determine rates of hydrocarbon biodegradation associated with natural cleansing at petroleum product spill sites. The one-dimensional model can be applied to analyze data from column experiments or from field sites where gas transport in the unsaturated zone is approximately vertical. A coupled, non-Fickian constitutive relation between fluxes and concentration gradients, together with the capability of incorporating heterogeneity with respect to model parameters, results in model applicability over a wide range of experimental and field conditions. When applied in a calibration mode, the model allows for the determination of constituent production/consumption rates as a function of the spatial coordinate. Alternatively, the model can be applied in a predictive mode to obtain the distribution of constituent concentrations and fluxes on the basis of assumed values of model parameters and a biodegradation hypothesis. Data requirements for the model are illustrated by analyzing data from a column experiment designed to determine the aerobic degradation rate of toluene in sediments collected from a gasoline spill site in Galloway Township, New Jersey. RP BAEHR, AL (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,810 BEAR TAVERN RD,W TRENTON,NJ 08628, USA. NR 15 TC 24 Z9 24 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD NOV PY 1995 VL 31 IS 11 BP 2877 EP 2882 DI 10.1029/95WR02077 PG 6 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TD805 UT WOS:A1995TD80500022 ER PT J AU NAIMAN, RJ MAGNUSON, JJ MCKNIGHT, DM STANFORD, JA KARR, JR AF NAIMAN, RJ MAGNUSON, JJ MCKNIGHT, DM STANFORD, JA KARR, JR TI FRESH-WATER ECOSYSTEMS AND THEIR MANAGEMENT - A NATIONAL INITIATIVE SO SCIENCE LA English DT Editorial Material ID FISHES C1 UNIV WISCONSIN,CTR LIMNOL,MADISON,WI 53711. US GEOL SURVEY,BOULDER,CO 80303. UNIV MONTANA,FLATHEAD LAKE BIOL STN,POLSON,MT 59860. RP NAIMAN, RJ (reprint author), UNIV WASHINGTON,CTR STREAMSIDE STUDIES,SEATTLE,WA 98195, USA. RI Naiman, Robert /K-3113-2012; OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 17 TC 44 Z9 50 U1 4 U2 11 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 27 PY 1995 VL 270 IS 5236 BP 584 EP 585 DI 10.1126/science.270.5236.584 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TB557 UT WOS:A1995TB55700023 ER PT J AU KOSKI, RA AF KOSKI, RA TI MARINE GEOLOGY - THE MAKING OF METAL DEPOSITS SO NATURE LA English DT Editorial Material ID MASSIVE SULFIDE DEPOSITS; MID-ATLANTIC RIDGE; CHIMNEYS; SNAKEPIT; HISTORY; TAG RP KOSKI, RA (reprint author), US GEOL SURVEY,PACIFIC MARINE GEOL BRANCH,345 MIDDLEFIELD RD,MS 999,MENLO PK,CA 94025, USA. NR 13 TC 2 Z9 2 U1 0 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD OCT 26 PY 1995 VL 377 IS 6551 BP 679 EP 680 DI 10.1038/377679a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TB469 UT WOS:A1995TB46900028 ER PT J AU CUFFEY, KM CLOW, GD ALLEY, RB STUIVER, M WADDINGTON, ED SALTUS, RW AF CUFFEY, KM CLOW, GD ALLEY, RB STUIVER, M WADDINGTON, ED SALTUS, RW TI LARGE ARCTIC TEMPERATURE-CHANGE AT THE WISCONSIN-HOLOCENE GLACIAL TRANSITION SO SCIENCE LA English DT Article ID GREENLAND ICE CORES; YOUNGER DRYAS EVENT; SURFACE-TEMPERATURE; GISP2; SHEET; PROFILES; RECORDS; CYCLE AB Analysis of borehole temperature and Greenland Ice Sheet Project II ice-core isotopic composition reveals that the warming from average glacial conditions to the Holocene in central Greenland was large, approximately 15 degrees C. This is at least three times the coincident temperature change in the tropics and mid-latitudes. The coldest periods of the last glacial were probably 21 degrees C colder than at present over the Greenland ice sheet. C1 US GEOL SURVEY,MENLO PK,CA 94025. PENN STATE UNIV,CTR EARTH SYST SCI,UNIVERSITY PK,PA 16802. PENN STATE UNIV,DEPT GEOSCI,UNIVERSITY PK,PA 16802. UNIV WASHINGTON,QUATERNARY ISOTOPE LAB,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT GEOSCI,SEATTLE,WA 98195. UNIV WASHINGTON,GEOPHYS PROGRAM,SEATTLE,WA 98195. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP CUFFEY, KM (reprint author), UNIV WASHINGTON,DEPT GEOL SCI,BOX 351310,SEATTLE,WA 98195, USA. NR 49 TC 301 Z9 312 U1 0 U2 38 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 20 PY 1995 VL 270 IS 5235 BP 455 EP 458 DI 10.1126/science.270.5235.455 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TA374 UT WOS:A1995TA37400037 ER PT J AU BUSZKA, PM ROSE, DL OZUNA, GB GROSCHEN, GE AF BUSZKA, PM ROSE, DL OZUNA, GB GROSCHEN, GE TI DETERMINATION OF NANOGRAM PER LITER CONCENTRATIONS OF VOLATILE ORGANIC-COMPOUNDS IN WATER BY CAPILLARY GAS-CHROMATOGRAPHY AND SELECTED-ION MONITORING MASS-SPECTROMETRY AND ITS USE TO DEFINE GROUNDWATER-FLOW DIRECTIONS IN EDWARDS-AQUIFER, TEXAS SO ANALYTICAL CHEMISTRY LA English DT Article AB method has been developed to measure nanogram per liter amounts of selected volatile organic compounds (VOCs) including dichlorodifluoromethane, trichlorofluoromethane, cis-1,2-dichloroethene, trichloroethene, tetrachloroethene, and the isomers of dichlorobenzene in water. The method uses purge-and-trap techniques on a 100 mL sample, gas chromatography with a megabore capillary column, and electron impact, selected ion monitoring mass spectrometry. Minimum detection levels for these compounds ranged from 1 to 4 ng/L in water. Recoveries from organic-free distilled water and natural groundwater ranged from 70.5% for dichlorodifluoromethane to 107.8% for 1,4-dichlorobenzene. Precision was generally best for cis-1,2-dichloroethene, tetrachloroethene, and the dichlorobenzene isomers and worst for dichlorodifluoromethane and trichlorofluoromethane. Blank data indicated persistent, trace-level introduction of dichlorodifluoromethane, 1,4-dichlorobenzene and tetrachloroethene to samples during storage and shipment at concentrations less than the method reporting limits. The largest concentrations of the selected VOCs in 27 water samples from the Edwards aquifer near San Antonio, TX, were from contined-zone wells near an abandoned landfill. The results defined a zone of water with no detectable VOCs in nearly all of the aquifer west of San Antonio and from part of the confined zone beneath San Antonio. C1 US GEOL SURVEY,AUSTIN,TX 78754. US GEOL SURVEY,NATL WATER QUAL LAB,ARVADA,CO 80002. US GEOL SURVEY,SAN ANTONIO,TX 78216. NR 22 TC 8 Z9 8 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1995 VL 67 IS 20 BP 3659 EP 3667 DI 10.1021/ac00116a008 PG 9 WC Chemistry, Analytical SC Chemistry GA RZ452 UT WOS:A1995RZ45200008 ER PT J AU PERSONIUS, SF AF PERSONIUS, SF TI LATE QUATERNARY STREAM INCISION AND UPLIFT IN THE FORE-ARC OF THE CASCADIA SUBDUCTION ZONE, WESTERN OREGON SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID PLATE BENEATH WASHINGTON; DE-FUCA PLATE; COAST RANGE; PACIFIC NORTHWEST; CONVERGENT MARGIN; HILLSLOPE EROSION; TECTONIC ROTATION; NORTHERN OREGON; MARINE TERRACES; DEFORMATION AB Documentation of a latest Pleistocene/earliest Holocene episode of strath formation and fluvial aggradation in the Oregon Coast Range provides a datum from which long-term bedrock stream incision rates are determined. Variations in long-term incision rates probably reflect cumulative differential uplift in the forearc of the Cascadia subduction zone, although factors such as bedrock and climatic controls and isostatic adjustments to erosion obscure the precise relationship between surface uplift and stream incision. Patterns of differential incision are most striking near the latitude of Newport, where a steep gradient divides a region of higher rates (similar to 0.6-0.9 mm/yr) in the northern Coast Range from a region of lower rates (similar to 0.1-0.3 mm/yr) in the central Coast Range. The steep incision gradient is nearly coincident with abrupt changes in marine terrace (similar to 80-125 kyr) uplift rates, the locations of Quaternary faults, and the southern flank of a saddle of low historic (similar to 40-70 years) uplift. The exact causes of these variable patterns of incision/uplift are unknown. Analogies with uplift patterns in other subduction zones and comparisons with other neotectonic data in the region indicate that patterns of differential incision probably are caused by variations in permanent strain accumulation along the Cascadia subduction zone. Such variations may be related to differences in seismic moment release during individual earthquakes, to changes in plate geometry or rates of wedge accretion, to segmentation of earthquake ruptures, and/or to deformation on active structures in the North American plate and accretionary wedge. RP PERSONIUS, SF (reprint author), US GEOL SURVEY, DENVER FED CTR, POB 25046, MS 966, DENVER, CO 80225 USA. NR 96 TC 52 Z9 55 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20193 EP 20210 DI 10.1029/95JB01684 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200014 ER PT J AU SAVAGE, JC LISOWSKI, M SVARC, JL GROSS, WK AF SAVAGE, JC LISOWSKI, M SVARC, JL GROSS, WK TI STRAIN ACCUMULATION ACROSS THE CENTRAL NEVADA SEISMIC ZONE, 1973-1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EASTERN CALIFORNIA; SHEAR ZONE; DEFORMATION; BASIN; FAULT; GAP AB Five trilateration networks extending for 280 km along the central Nevada seismic zone (1915 Pleasant Valley, M = 7.3; 1954 Dixie Valley, M = 6.8; 1954 Stillwater, M = 6.8; 1954 Rainbow Mountain, M = 6.6; 1954 Fairview Peak, M = 7.1; and 1932 Cedar Mountain, M = 7.2) have been surveyed 8 times since 1973 to determine deformation along the zone. Within the precision of measurement the deformation appears uniform along the zone and is described by the principal strain rates 0.036 +/- 0.008 mu strain/yr N60 degrees W +/- 3 degrees and -0.031 +/- 0.008 mu strain/yr N30 degrees E +/- 3 degrees, extension reckoned positive. The observed strain rates are consistent with simple, right-lateral, teaser shear at the rate of 0.033 mu strain/yr across a shear zone striking N15 degrees W. This central Nevada shear zone appears to be the northward continuation of the eastern California shear zone. The orientation of the strike-slip and normal-slip ruptures within the central Nevada seismic zone are consistent with principal stress axes parallel to the measured principal strain rate axes. Space-based geodetic measurements (very long baseline interferometry) indicate that the relative motion accommodated across the Basin and Range province west of fly, Nevada, is about 9.1+/-1.5 mm/yr N16 degrees W +/- 8 degrees (Dixon et al., 1995.) Notice that the right-lateral shear zone postulated to explain deformation in the central Nevada seismic zone is properly oriented to accommodate that relative motion. Howsoever, a 135-km effective width of the shear zone would be required to accommodate all of the 9.1 mm/yr relative motion st the strain rates observed in the Nevada seismic zone; only about 3 mm/yr of that relative motion is accommodated within the span of the trilateration networks. RP SAVAGE, JC (reprint author), US GEOL SURVEY, MS-977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 33 TC 26 Z9 26 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20257 EP 20269 DI 10.1029/95JB01872 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200018 ER PT J AU KING, ME SVARC, JL FOGLEMAN, EB GROSS, WK CLARK, KW HAMILTON, GD STIFFLER, CH SUTTON, JM AF KING, ME SVARC, JL FOGLEMAN, EB GROSS, WK CLARK, KW HAMILTON, GD STIFFLER, CH SUTTON, JM TI CONTINUOUS GPS OBSERVATIONS ACROSS THE HAYWARD FAULT, CALIFORNIA, 1991-1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CREEP AB In September 1991, the U.S. Geological Survey began continuous operation of two permanent Global Positioning System (GPS) sites near the Hayward fault. We use two and one half years of data from an 8-km baseline to investigate GPS processing strategies, errors in the time and frequency domains and the uncertainties of rates of change calculated from such data. Experiments with session lengths show that at least 6 hours of data should be used to obtain a precision of 2 to 4 mm. Experiments with broadcast and improved orbits show that the broadcast orbit is sufficient for this short baseline. Single-frequency solutions have larger rms scatter; for scenarios made mostly in daylight, ionospheric delay systematically shortens the baseline length by 2.4 parts per million for L1 and 4.0 parts per million for L2. For the dual-frequency results, the rms scatter about the best-fitting straight line is:2.1 mm for baseline length, 2.2 mm for north, 2.9 mm for east, and 11.2 mm for vertical. For Winton relative to Chabot, the rates of change are -0.6 +/- 0.1 mm/yr in length, 2.8 +/- 0.1 mm/yr in north, -8.1 +/- 0.2 mm/yr in east, and -8.1 +/- 0.6 mm/yr in vertical. The baseline rate of change is consistent with right-lateral shear across the Hayward fault but is not consistent with the -3.5 mm/yr predicted by the model of Lienkaemper et al. (1991). The large westward and downward motion of Winton relative to Chabot may be due to monument instability. Power spectra appear white at high frequencies; the estimated standard deviations for periods shorter than 5 days are 1.2 mm for length and north, 1.9 mm for east, and 5.5 mm for vertical. Power spectral density increases only slightly as frequency decreases from 0.2 to 0.03 cycle per day, and there is no distinct corner. In particular, no characteristic 1/f(2) signature of random walk monument noise emerges from the white noise. Estimated autocorrelations for length, north, east, and vertical fall to about 0.1 for lag times shorter than 10 days and fluctuate about zero for lag times longer than about 25 days. Because the time series is short, it is possible that random walk monument noise exists but is undetectable in the estimated power spectral density and autocorrelation functions. We use the estimated full covariance matrix to calculate the standard deviations of the baseline rate of change for various sampling schemes. The theoretical standard deviation of dL/dt determined from 1 year of daily observations is 0.28 times that determined from 1 year of annual observations. We can obtain a similar uncertainty from 2 years of measurements made every 30 days and better results from 5 years of annual measurements. However, daily measurements allow the detection and correction of offsets that sometimes occur with equipment or firmware changes. RP KING, ME (reprint author), US GEOL SURVEY, MS-977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 18 TC 23 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20271 EP 20283 DI 10.1029/95JB02035 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200019 ER PT J AU MORI, J HELMBERGER, DV AF MORI, J HELMBERGER, DV TI LOCALIZED BOUNDARY-LAYER BELOW THE MID-PACIFIC VELOCITY ANOMALY IDENTIFIED FROM A PCP PRECURSOR SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CORE-MANTLE BOUNDARY; THERMAL STATE; EARTH; WAVES; BASE; IRON AB Dense record sections from deep earthquakes in Fiji and Argentina recorded on hundreds of short-period stations in California at distances of 81 degrees to 85 degrees are used to investigate the detailed P wave velocity structure above the core-mantle boundary (CMB). In the Fiji data a secondary phase arriving 2 to 4 s after the direct P is identified as a precursor to PcP. This phase provides good evidence for a reflection off the top of a thin low-velocity layer above the CMB. Comparisons to synthetic seismograms indicate a layer thickness of 10 km and a velocity reduction of 5%-10% compared to the overlying mantle. A record section from an Argentina event does not show the PcP precursor, indicating that the low-velocity layer is not a global feature. This thin low-velocity layer is in the same place as a much larger S wave velocity anomaly in the lower mantle and is probably indicative of a boundary layer just above the CMB under the mid-Pacific. C1 CALTECH, SEISMOL LAB, PASADENA, CA 91125 USA. RP MORI, J (reprint author), US GEOL SURVEY, 525 S WILSON AVE, PASADENA, CA 91106 USA. NR 24 TC 91 Z9 93 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20359 EP 20365 DI 10.1029/95JB02243 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200026 ER PT J AU MUNSON, CG THURBER, CH LI, YP OKUBO, PG AF MUNSON, CG THURBER, CH LI, YP OKUBO, PG TI CRUSTAL SHEAR-WAVE ANISOTROPY IN SOUTHERN HAWAII - SPATIAL AND TEMPORAL ANALYSIS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ANZA SEISMIC NETWORK; FAULT-PLANE SOLUTIONS; MAUNA-LOA VOLCANO; EARTHQUAKE PREDICTION; QUANTITATIVE MEASUREMENTS; POLARIZATION ANALYSIS; EARTHS CRUST; STRESS; KAOIKI; CALIFORNIA AB Split shear wave arrivals are analyzed in seismograms from local earthquakes in southern Hawaii recorded at five temporary arrays and one permanent network station. We identify split shear wave arrivals by their orthogonally polarized pulses, linear particle motions, and similar waveforms and estimate the delay time for the slow shear wave arrival (S-2) using a waveform cross-correlation method. Consistent leading shear wave polarizations were measured at the majority of our stations. Comparison of observed and predicted shear wave polarizations confirms that the former are due to anisotropy rather than earthquake source mechanism. Agreement between fast shear wave (S-1) polarizations and independently estimated directions of the maximum horizontal compressive stress (sigma(H)) for the Ainapo and Punaluu Gulch arrays leads us to conclude that the predominant source of the observed anisotropy for these two areas is stress-aligned cracks consistent with the extensive dilatancy anisotropy (EDA) hypothesis. Two distinct S-1 polarization directions were observed over distances less than 1 km for the Bird Park and South Flank arrays. S-1 polarizations parallel to the NE striking Kaoiki Pall fault system for the Bird Park array combined with a nonhorizontal maximum principal stress (sigma(1)) for the South Flank region suggest stress-induced cracks aligned by nearby faulting as a source for the observed anisotropy. Large station-to-station variations in S-1 polarization and the relationship between delay time and event depth for arrays in the Kaoiki and South Flank regions provide evidence for anisotropy that is predominantly shallow rather than pervasive. Average delay times for the five arrays vary from about 100 to 230 ms, with standard deviations of the order of 30 ms. Estimated anisotropic velocity variations and crack densities exceeding 10% indicate that the upper crust of southern Hawaii is highly fractured. A search for possible temporal changes in delay time associated with the 1983 Kaoiki main shock (M(L) = 6.6), at a station near the epicenter, finds no evidence for change. C1 UNIV WISCONSIN, DEPT GEOL & GEOPHYS, MADISON, WI 53706 USA. MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02139 USA. US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HAWAII NATL PK, HI 96718 USA. NR 41 TC 30 Z9 31 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20367 EP 20377 DI 10.1029/95JB01288 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200027 ER PT J AU WEILAND, CM STECK, LK DAWSON, PB KORNEEV, VA AF WEILAND, CM STECK, LK DAWSON, PB KORNEEV, VA TI NONLINEAR TELESEISMIC TOMOGRAPHY AT LONG VALLEY CALDERA, USING 3-DIMENSIONAL MINIMUM TRAVEL-TIME RAY-TRACING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COMPRESSIONAL WAVE VELOCITY; UPPER CRUSTAL STRUCTURE; EASTERN CALIFORNIA; ATTENUATION STRUCTURE; INVERSION; ANOMALIES; 3-D; OPTIMIZATION; LITHOSPHERE; REGION AB We explore the impact of three-dimensional minimum travel time ray tracing on nonlinear teleseismic inversion. This problem has particular significance when trying to image strongly contrasting low-velocity bodies, such as magma chambers, because strongly refracted and/or diffracted rays may precede the direct P wave arrival traditionally used in straight-ray seismic tomography. We use a simplex-based ray tracer to compute the three-dimensional, minimum travel time ray paths and employ an iterative inversion technique to cope with nonlinearity. Results from synthetic data show that our algorithm results in better model reconstructions compared with traditional straight-ray inversions, We reexamine the teleseismic data collected at Long Valley caldera by the U.S. Geological Survey. The most prominent feature of our result is a 25-30% low-velocity zone centered at 11.5 km depth beneath the northwestern quadrant of the caldera. Beneath this at a depth of 24.5 km is a more diffuse 15% low-velocity zone. In general, the low velocities tend to deepen to the south and east, We interpret the shallow feature to be the residual Long Valley caldera magma chamber, while the deeper feature may represent basaltic magmas ponded in the midcrust. The deeper position of the prominent low-velocity region in comparison to earlier tomographic images is a result of using three-dimensional rays rather than straight rays in our ray tracing. The magnitude of our low-velocity anomaly is a factor of similar to 3 times larger than earlier models from linear arrival time inversions and is consistent with models based on observations of ray bending at sites within the caldera. Our results imply the presence of anywhere from 7 to 100% partial melt beneath the caldera. C1 LOS ALAMOS NATL LAB, GEOENGN GRP, LOS ALAMOS, NM USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV EARTH SCI, BERKELEY, CA 94720 USA. RP WEILAND, CM (reprint author), UNIV CALIF SANTA BARBARA, DEPT GEOL, SANTA BARBARA, CA 93106 USA. NR 40 TC 59 Z9 59 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 10 PY 1995 VL 100 IS B10 BP 20379 EP 20390 DI 10.1029/95JB01147 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ312 UT WOS:A1995RZ31200028 ER PT J AU RICE, SB FREUND, H HUANG, WL CLOUSE, JA ISAACS, CM AF RICE, SB FREUND, H HUANG, WL CLOUSE, JA ISAACS, CM TI APPLICATION OF FOURIER-TRANSFORM INFRARED-SPECTROSCOPY TO SILICA DIAGENESIS - THE OPAL-A TO OPAL-CT TRANSFORMATION SO JOURNAL OF SEDIMENTARY RESEARCH SECTION A-SEDIMENTARY PETROLOGY AND PROCESSES LA English DT Article ID MONTEREY FORMATION; TEMBLOR RANGE; CALIFORNIA; SHALE; SEA AB An important goal in silica diagenesis research is to understand the kinetics of opal transformation from noncrystalline opal-A to the disordered silica polymorph opal-CT, Because the conventional technique for monitoring the transformation, powder X-ray diffraction (XRD), is applicable only to phases with long-range order, we used Fourier transform infrared spectroscopy (FTIR) to monitor the transformation. We applied this technique, combined with XRD and TEM, to experimental run products and natural opals from the Mon terey Formation and from siliceous deposits in the western Pacific Ocean. Using a ratio of two infrared absorption intensities (omega = I-472cm-1-/I-500cm-1), the relative proportions of opal-A and opal-CT can be determined. The progress of the transformation is marked by changes in slope of omega vs. depth or time when a sufficient stratigraphic profile is available. There are three stages in the opal-A to opal-CT reaction: (1) opal A dissolution; (2) opal-CT precipitation, whose end point is marked by completion of opal A dissolution; and (3) opal-CT ordering, during which tridymite stacking is eliminated in favor of cristobalite stacking. C1 EXXON PROD RES CO,HOUSTON,TX 77252. US GEOL SURVEY,MENLO PK,CA 94025. NR 30 TC 27 Z9 28 U1 2 U2 10 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 1073-130X J9 J SEDIMENT RES A JI J. Sediment. Res. Sect. A-Sediment. Petrol. Process. PD OCT 2 PY 1995 VL 65 IS 4 BP 639 EP 647 PG 9 WC Geology SC Geology GA TA111 UT WOS:A1995TA11100006 ER PT J AU MAGOON, LB AF MAGOON, LB TI THE PLAY THAT COMPLEMENTS THE PETROLEUM SYSTEM - A NEW EXPLORATION EQUATION SO OIL & GAS JOURNAL LA English DT Editorial Material RP MAGOON, LB (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD OCT 2 PY 1995 VL 93 IS 40 BP 83 EP 85 PG 3 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA RX661 UT WOS:A1995RX66100017 ER PT J AU ROWAN, LC POOLE, FG PAWLEWICZ, MJ AF ROWAN, LC POOLE, FG PAWLEWICZ, MJ TI THE USE OF VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTRA FOR ESTIMATING ORGANIC-MATTER THERMAL MATURITY SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID MINERALS; ROCKS; SHALE; IR AB Measurements of visible and near-infrared spectral reflectance of 41 samples of mudstone, siltstone, and carbonate rocks representing two major depositional settings in Nevada were compared to vitrinite reflectance (R(o)) and hydrogen index (HI) measurements to determine the relation between spectral reflectance and organic matter (OM) maturity. The samples range in age from Devonian to Paleogene and have highly variable total organic carbon (TOC) contents, recycled OM contents, and kerogen compositions. Visible and near-infrared spectral reflectance of the samples changes systematically as OM maturity increases from submature to supermature (R(o) range of 0.28 to 4.32); therefore, spectral reflectance generally can be used to estimate the thermal maturity of the contained OM. The sum of several ratios (compound ratio) used to express spectral changes in the visible and near-infrared wavelength region is high for most submature samples, decreases rapidly with increasing R(o) into the mature range, and then decreases less rapidly through the remaining mature range and the supermature range. A similar trend is displayed in the plot of HI vs. compound ratio. Some spectra are affected by iron absorption features and the presence of recycled OM. Iron absorption generally causes the compound ratio values to be anomalously high relative to the OM maturity, whereas recycled OM results in unusually low ratio values. TOC variations do not affect the ratio-OM maturity relation substantially. Iron absorption occurs in the short wavelength part of the visible and near-infrared region and is readily identified in the laboratory spectra. Spectra affected by recycled OM were identified by using a pair of ratios that expresses the difference in spectral shape between these spectra and spectra of supermature samples, which they resemble. Samples containing recycled kerogen are much more numerous from the Mississippian prodelta basin of the Antler foreland basin than from the Antler orogene; this difference indicates derivation of much of the kerogen from the orogene. C1 US GEOL SURVEY,FED CTR,LAKEWOOD,CO 80225. RP ROWAN, LC (reprint author), US GEOL SURVEY,NATL CTR,MS-927,RESTON,VA 22092, USA. NR 21 TC 3 Z9 3 U1 1 U2 4 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD OCT PY 1995 VL 79 IS 10 BP 1464 EP 1480 PG 17 WC Geosciences, Multidisciplinary SC Geology GA RY628 UT WOS:A1995RY62800003 ER PT J AU WANG, YS MILLER, DR ANDERSON, DE MCMANUS, ML AF WANG, YS MILLER, DR ANDERSON, DE MCMANUS, ML TI A LAGRANGIAN STOCHASTIC-MODEL FOR AERIAL SPRAY TRANSPORT ABOVE AN OAK FOREST SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID TURBULENT AIR-FLOW; RANDOM-WALK MODEL; PARTICLE TRAJECTORIES; INHOMOGENEOUS TURBULENCE; AGRICULTURAL SPRAYS; VELOCITY VARIANCE; SPORE DISPERSAL; HEAVY-PARTICLES; PLANT CANOPIES; SURFACE-LAYER AB An aerial spray droplets' transport model has been developed by applying recent advances in Lagrangian stochastic simulation of heavy particles. A two-dimensional Lagrangian stochastic model was adopted to simulate the spray droplet dispersion in atmospheric turbulence by adjusting the Lagrangian integral time scale along the drop trajectory. The other major physical processes affecting the transport of spray droplets above a forest canopy, the aircraft wingtip vortices and the droplet evaporation, were also included in each time step of the droplets' transport. The model was evaluated using data from an aerial spray field experiment. In generally neutral stability conditions, the accuracy of the model predictions varied from run-to-run as expected. The average root-mean-square error was 24.61 IU cm(-2), and the average relative error was 15%. The model prediction was adequate in two-dimensional steady wind conditions, but was less accurate in variable wind condition, The results indicated that the model can simulate successfully the ensemble average transport of aerial spray droplets under neutral, steady atmospheric wind conditions. C1 UNIV CONNECTICUT,DEPT NAT RESOURCES MANAGEMENT & ENGN,STORRS,CT 06269. US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,DENVER,CO 80225. US FOREST SERV,NE FOREST EXPT STN,HAMDEN,CT. NR 39 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD OCT PY 1995 VL 76 IS 3-4 BP 277 EP 291 DI 10.1016/0168-1923(95)02221-I PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA TE154 UT WOS:A1995TE15400008 ER PT J AU LAVERMAN, AM BLUM, JS SCHAEFER, JK PHILLIPS, EJP LOVLEY, DR OREMLAND, RS AF LAVERMAN, AM BLUM, JS SCHAEFER, JK PHILLIPS, EJP LOVLEY, DR OREMLAND, RS TI GROWTH OF STRAIN SES-3 WITH ARSENATE AND OTHER DIVERSE ELECTRON-ACCEPTORS SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SELENATE REDUCTION; ELEMENTAL SELENIUM; ANAEROBIC-BACTERIA; SPECIATION; SPIRILLUM-5175; ADSORPTION; CHEMISTRY; SEDIMENTS; IRON; PH AB The selenate-respiring bacterial strain SES-3 was able to use a variety of inorganic electron accepters to sustain growth. SES-3 grew with the reduction of arsenate to arsenite, Fe(III) to Fe(II), or thiosulfate to sulfide, It also grew in medium in which elemental sulfur, Mn(IV), nitrite, trimethylamine N-oxide, or fumarate was provided as an electron acceptor. Growth on oxygen was microaerophilic. There was no growth with arsenite or chromate, Washed suspensions of cells grown on selenate or nitrate had a constitutive ability to reduce arsenate but were unable to reduce arsenite. These results suggest that strain SES-3 may occupy a niche as an environmental opportunist by being able to take advantage of a diversity of electron accepters. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,RESTON,VA 22092. NR 38 TC 129 Z9 138 U1 4 U2 12 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD OCT PY 1995 VL 61 IS 10 BP 3556 EP 3561 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA RY071 UT WOS:A1995RY07100007 PM 16535143 ER PT J AU GIESY, JP BOWERMAN, WW MORA, MA VERBRUGGE, DA OTHOUDT, RA NEWSTED, JL SUMMER, CL AULERICH, RJ BURSIAN, SJ LUDWIG, JP DAWSON, GA KUBIAK, TJ BEST, DA TILLITT, DE AF GIESY, JP BOWERMAN, WW MORA, MA VERBRUGGE, DA OTHOUDT, RA NEWSTED, JL SUMMER, CL AULERICH, RJ BURSIAN, SJ LUDWIG, JP DAWSON, GA KUBIAK, TJ BEST, DA TILLITT, DE TI CONTAMINANTS IN FISHES FROM GREAT LAKES-INFLUENCED SECTIONS AND ABOVE DAMS OF 3 MICHIGAN RIVERS .3. IMPLICATIONS FOR HEALTH OF BALD EAGLES SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DOUBLE-CRESTED CORMORANTS; CHICK-EDEMA DISEASE; HERRING-GULLS; 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN EQUIVALENTS; ENVIRONMENTAL CONTAMINANTS; POLYCHLORINATED-BIPHENYLS; BREEDING SUCCESS; EATING BIRDS; EGGS; ORGANOCHLORINE AB Recently, there have been discussions of the relative merits of passage of fishes around hydroelectric dams on three rivers (Au Sable, Manistee, and Muskegon) in Michigan. A hazard assessment was conducted to determine the potential for adverse effects on bald eagles that could consume such fishes from above and below dams on the three primary rivers. The hazard assessments were verified by comparing the reproductive productivities of eagles nesting in areas where they ate vl primarily fish from either above or below darns on the three primary rivers, as well as on two additional rivers in Michigan, the Menominee and Thunder Bay. Concentrations of organochlorine insecticides (OCI), polychlorinated biphenyls (total PCBs), 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), and total mercury (Hg) were measured in composite samples of fishes from above and below hydroelectric darns on the Manistee and Muskegon Rivers, which flow into Lake Michigan, and the Au Sable River, which flows into Lake Huron. Mean concentrations of OCI, total PCBs, and TCDD-EQ were all greater in fishes from below the dams than in those from above. The hazard assessment indicated that current concentrations of Hg and OCI other than DDT (DDT + DDE + DDD) in fish from neither above nor below dams would present a significant hazard to bald eagles (Haliaeetus leucocephalus). Both total PCBs and TCDD-EQ in fishes from below the darns currently present a significant hazard to bald eagles, since their mean hazard quotients (HQ) were all greater than one. C1 MICHIGAN STATE UNIV, INST ENVIRONM TOXICOL, E LANSING, MI 48824 USA. SERE GRP, VICTORIA, BC V8P 3C8, CANADA. CONSUMERS POWER CO, DEPT ENVIRONM, JACKSON, MI 49201 USA. MICHIGAN STATE UNIV, DEPT ANIM SCI, E LANSING, MI 48824 USA. US FISH & WILDLIFE SERV, E LANSING FIELD OFF, E LANSING, MI 48823 USA. MIDWEST RES CTR, NATL BIOL SERV, COLUMBIA, MO 65201 USA. RP GIESY, JP (reprint author), MICHIGAN STATE UNIV, PESTICIDE RES CTR, DEPT WILDLIFE & FISHERIES, E LANSING, MI 48824 USA. RI Mora, Miguel/B-1344-2009 FU NIEHS NIH HHS [ES-04911] NR 84 TC 56 Z9 56 U1 2 U2 16 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 EI 1432-0703 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 1995 VL 29 IS 3 BP 309 EP 321 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RR148 UT WOS:A1995RR14800006 PM 7487154 ER PT J AU WILLIAMS, LL GIESY, JP VERBRUGGE, DA JURZYSTA, S STROMBORG, K AF WILLIAMS, LL GIESY, JP VERBRUGGE, DA JURZYSTA, S STROMBORG, K TI POLYCHLORINATED-BIPHENYLS AND 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN EQUIVALENTS IN EGGS OF DOUBLE-CRESTED CORMORANTS FROM A COLONY NEAR GREEN-BAY, WISCONSIN, USA SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DIBENZO-PARA-DIOXINS; AROMATIC-HYDROCARBONS; RAINBOW-TROUT; GREAT-LAKES; TOXICITY; BIRDS; CONGENERS; MIXTURES; RESIDUES; AROCLOR AB Great Lakes colonial waterbirds have experienced poor reproduction and a greater incidence of birth defects than those in remote areas. An egg was collected from each of 1,000 marked cormorant nests at Spider Island (Lake Michigan): Nine pools comprised of three eggs were randomly selected for instrumental quantification of polychlorinated biphenyls (PCB) congeners, calculation of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEq) and measurement of equivalents by bioassay (TCDD-EQ). PCB analysis of the nine samples was semiautomated with high performance liquid chromatography (HPLC) columns including a porous graphitic carbon column. TEqs were calculated from concentrations of PCB congeners and bioassay-derived toxic equivalency factors (TEfs), and TCDD-EQ were measured directly with an H4IIE bioassay. Total PCB concentrations ranged from 9.7 to 38 mu g/g, wet weight (ww). Mean concentrations of PCB 77, 126, and 169 were 2, 7, and 1 ng/g, ww. The mean TEqs and TCDD-EQ were 150 and 350 pg/g, ww, respectively. Thus, PCB congeners contributed less than 50% of the total TCDD-EQs as measured by the bioassay. C1 MICHIGAN STATE UNIV,PESTICIDE RES CTR,DEPT FISHERIES & WILDLIFE,E LANSING,MI 48824. MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,E LANSING,MI 48824. US FISH & WILDLIFE SERV,GREEN BAY FIELD OFF,GREEN BAY,WI 54311. FU NIEHS NIH HHS [ES-04911] NR 27 TC 13 Z9 13 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 1995 VL 29 IS 3 BP 327 EP 333 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RR148 UT WOS:A1995RR14800008 PM 7487156 ER PT J AU HEATON, SN BURSIAN, SJ GIESY, JP TILLITT, DE RENDER, JA JONES, PD VERBRUGGE, DA KUBIAK, TJ AULERICH, RJ AF HEATON, SN BURSIAN, SJ GIESY, JP TILLITT, DE RENDER, JA JONES, PD VERBRUGGE, DA KUBIAK, TJ AULERICH, RJ TI DIETARY EXPOSURE OF MINK TO CARP FROM SAGINAW BAY, MICHIGAN .2. HEMATOLOGY AND LIVER PATHOLOGY SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID OTTER LUTRA-LUTRA; GREAT-LAKES FISH; POLYCHLORINATED-BIPHENYLS; COMPARATIVE TOXICOLOGY; TISSUE RESIDUES; RHESUS-MONKEYS; MUSTELA-VISON; TOXICITY; REPRODUCTION; RATS AB The effects of consumption of environmental contaminants contained in carp (Cyprinus carpio) from Saginaw Bay, Michigan on various hematological parameters and liver integrity of adult female mink (Mustela vison) were determined. Mink were fed diets that contained 0 (control), 10, 20, or 40% carp prior to and throughout the reproductive period (182 days). The diets contained 0.015, 0.72, 1.53, and 2.56 mg polychlorinated biphenyls (PCBs)/kg diet and 1.0, 19, 40, and 81 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs)/g diet, respectively. Mink fed the diets containing carp showed a general dose-dependent occurrence of clinical signs commonly associated with chlorinated hydrocarbon toxicity, including listlessness, nervousness when approached, anorexia, and melena. Erythrocyte counts were less in mink exposed to Saginaw Bay carp than in controls, while the number of white blood cells was greater than in controls. Significant differences (p < 0.05) in the concentrations of neutrophils, lymphocytes, monocytes, and eosinophils were also found between the control and carp-fed groups, but are considered to be of limited clinical or biological importance. Hematocrit values for the mink fed the 20 and 40% carp diets were significantly less than those of mink in the control and 10% carp groups. There were no significant differences in hemoglobin concentrations among the groups. Necropsies revealed enlarged yellowish livers in many of the carp-fed mink, especially those fed the 40% carp diet. Liver, spleen, and lung weights of carp-fed mink were significantly greater than those of control mink. Histopathologic examination of the livers revealed various degrees of congestion, hepatocellular fatty changes, and scattered portal lymphocytic infiltration which were most prevalent in mink fed the carp diets. These clinical signs, hematological effects, and histologic alterations are similar to those previously described for chlorinated hydrocarbon toxicoses in mink. C1 MICHIGAN STATE UNIV,DEPT ANIM SCI,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT WILDLIFE & FISHERIES,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PATHOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,INST EXPTL TOXICOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,PESTICIDE RES CTR,E LANSING,MI 48824. NATL BIOL SURVEY,MIDWEST SCI CTR,COLUMBIA,MO 65201. US FISH & WILDLIFE SERV,E LANSING,MI 48823. RI Jones, Paul/O-2046-2015 OI Jones, Paul/0000-0002-7483-5380 NR 58 TC 20 Z9 20 U1 0 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 1995 VL 29 IS 3 BP 411 EP 417 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RR148 UT WOS:A1995RR14800020 PM 7487160 ER PT J AU Warnock, SE Takekawa, JY AF Warnock, SE Takekawa, JY TI Habitat preferences of wintering shorebirds in a temporally changing environment: Western Sandpipers in the San Francisco Bay estuary SO AUK LA English DT Article ID HOME RANGE; MIGRATION; INCREASE; WADERS AB We examined habitat preferences of 106 radio-marked Western Sandpipers (Calidris mauri) in the San Francisco Bay estuary during winter and spring at two scales: comparing proportions of habitats in their home range with habitats available in the study area (second-order selection), and comparing proportions of radio locations in different habitats with their availability in the home range (third-order selection). Daily and seasonal habitat preferences differed significantly as habitat availability changed temporally. Under second-order selection, Western Sandpipers preferred tidal sloughs and mud flats on winter low tides, and salt-pond levees at high tides. They preferred salt-pond levees and mud flats at low tides, and salt-pond levees at high tides under third-order selection. During the spring, their preferred habitats were drained and tidal salt ponds, and seasonal wetlands at high tide. At low tide, their preferred habitats were tidal sloughs and tidal salt ponds. Salt-marsh plains were the least preferred habitats during both seasons. Adults were more selective than juveniles in use of low tide habitats, but sail-pond levees were the most preferred habitats for both. Habitat preferences varied considerably when different estimates of habitat availability and use were used. If mud-flat habitats were measured as linear foraging areas along the tide line, the preference for those habitats increased from second to first. When second-order selection was estimated from radio locations rather than home ranges, the resulting composition was similar to third-order selection. Our results suggest that regional conservation plans that restore salt marshes for the benefit of endangered species must consider the effects of losing artificial salt-pond habitats, which are locally important for sandpipers. C1 US FISH & WILDLIFE SERV,PRAIRIE & NO WILDLIFE RES CTR,FIELD STN,DIXON,CA 95620. NR 36 TC 59 Z9 62 U1 0 U2 14 PU AMER ORNITHOLOGISTS UNION PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 SN 0004-8038 J9 AUK JI AUK PD OCT PY 1995 VL 112 IS 4 BP 920 EP 930 PG 11 WC Ornithology SC Zoology GA UF267 UT WOS:A1995UF26700009 ER PT J AU LIU, HP AF LIU, HP TI APPLICATION OF BAND-LIMITED ANELASTIC MODELS TO WAVE-PROPAGATION IN HIGHLY ATTENUATIVE MEDIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID VISCOELASTIC MEDIA; DISPERSION; SCATTERING; SURFACE; STRAIN AB Because of its simple form, a bandlimited, four-parameter anelastic model that yields nearly constant midband Q for low-loss materials is often used for calculating synthetic seismograms. The four parameters used in the Literature to characterize anelastic behavior are tau(1), tau(2), Q(m), and M(R) in the relaxation-function approach (s(1) = 1/tau(1) and s(2) = 1/tau(2) are angular frequencies defining the bandwidth, and M(R) is the relaxed modulus, and Q(m) is approximately the midband quality factor when Q(m) much greater than 1); or tau(1), tau(2), Q(m), and M(R) in the creep-function approach (s(1) = 1/tau(1), and s(2) = 1/tau(2) are angular frequencies defining the bandwidth, and Q(m) is approximately the midband quality factor when Q(m) much greater than 1). In practice, it is often the case that, for a particular medium, the quality factor Q(omega(0)) and phase velocity c(omega(0)) at an angular frequency omega(0) (s(1) < omega(0) < s(2); s(1) < omega(0) < s(2)) are known from held measurements. If values are assigned to tau(1), and tau(2) (tau(2) < tau(1)), or to tau(1) and tau(2) (tau(2) < tau(1)), then the two remaining parameters, Q(m) and M(R), or Q(m), and M(R), can be obtained from Q(omega(0) and c(omega(0)). However, for highly attenuative media, e.g., Q(omega(0)) less than or equal to 5, Q(omega) can become highly skewed and negative at low frequencies (for the relaxation-function approach) or at high frequencies (for the creep-function approach) if this procedure is followed. A negative Q(omega) is unacceptable because it implies an increase in energy for waves propagating in a homogeneous and attenuative medium. This article shows that given (tau(1), tau(2), omega(0)) or (tau(1), tau(2), omega(0)), a lower limit of Q(omega(0)) exists for a bandlimited, four-parameter anelastic model. In the relaxation-function approach, the minimum permissible Q(omega(0)) is given by In [(1 + omega(0)(2) tau(1)(2))/(1 + omega(0)(2) tau(2)(2))]/{2 arctan [omega(0)(tau(1) - tau(2))/(1 + omega(0)(2) tau(1) tau(2))]}. In the creep-function approach, the minimum permissible Q(omega(0)) is given by {2 In (tau(1)/tau(2)) - In [(1 + omega(0)(2) tau(1)(2))/(1 + omega(0)(2) tau(2)(2))])/{2 arctan omega(0)(tau(1) - tau(2))/(1 + omega(0)(2) tau(1) tau(2))]}. The more general statement that, for a given set of relaxation mechanisms, a lower limit exists for Q(omega(0)) is also shown to hold. Because a nearly constant midband Q cannot be achieved for highly attenuative media using a four-parameter anelastic model, a bandlimited, six-parameter anelastic model that yields a nearly constant midband Q for such media is devised; an expression for the minimum permissible Q(omega(0)) is given. Six-parameter anelastic models with quality factors Q similar to 5 and Q similar to 16, constant to 6% over the frequency range 0.5 to 200 Hz, illustrate this result. In conformity with field observations that Q(omega) for near-surface earth materials is approximately constant over a wide frequency range, the bandlimited, six-parameter anelastic models are suitable for modeling wave propagation in highly attenuative media for bandlimited time functions in engineering and exploration seismology. RP LIU, HP (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1995 VL 85 IS 5 BP 1359 EP 1372 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TA774 UT WOS:A1995TA77400007 ER PT J AU FISCHER, KM SALVATI, LA HOUGH, SE GONZALEZ, E NELSEN, CE ROTH, EG AF FISCHER, KM SALVATI, LA HOUGH, SE GONZALEZ, E NELSEN, CE ROTH, EG TI SEDIMENT-INDUCED AMPLIFICATION IN THE NORTHEASTERN UNITED-STATES - A CASE-STUDY IN PROVIDENCE, RHODE-ISLAND SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-FRANCISCO-BAY; EARTHQUAKE SITE RESPONSE; 5-SECOND MICRO-TREMORS; GROUND MOTION; 1-SECOND; MICROTREMORS; RESONANCES; STATION; VALLEY AB We employed ambient-noise measurements to assess the potential for seismic site response in sediment-filled valleys that intersect beneath downtown Providence, Rhode Island, At eight valley stations and at two sites on an adjacent bedrock highland, we recorded ground motion from two types of sources: pile drivers at a local construction site and ambient microtremors. At all valley sites where sediment thicknesses exceed 10 m, spectral ratios contain amplitude peaks at frequencies of 1.5 to 3.0 Hz. In contrast, spectral ratios from the two sites on the bedrock highland where sediment cover is less than 4-m thick are relatively flat within this frequency range. A variety of borehole logs identified two fundamental sediment types (soft sediment and a consolidated glacial till) and were used to map layer thicknesses over the entire study region. Refraction data constrained P-wave velocity in the bedrock to be 3680 +/- 160 m/sec and indicated two soft-sediment layers with P-wave velocities of 300 +/- 50 and 1580 +/- 120 m/sec. Using a one-dimensional reflection matrix technique, we matched the spectral-ratio peak observed at each valley site with the frequency of fundamental resonance predicted for local layer thicknesses and velocities. A positive correlation between the best-fitting soft-sediment velocities and bedrock depth may reflect greater compaction in the deepest sediments or a locally two-dimensional sediment resonance at the deepest sediment sites. We conclude that unconsolidated sediment layers under downtown Providence have the potential to amplify earthquake ground motion at frequencies damaging to engineered structures. C1 US GEOL SURVEY,PASADENA,CA 91106. RP FISCHER, KM (reprint author), BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912, USA. NR 33 TC 3 Z9 3 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1995 VL 85 IS 5 BP 1388 EP 1397 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TA774 UT WOS:A1995TA77400010 ER PT J AU EVANS, JR PITT, AM AF EVANS, JR PITT, AM TI RELIABLE AUTOMATIC DETECTION OF LONG-PERIOD VOLCANIC EARTHQUAKES AT LONG-VALLEY CALDERA, CALIFORNIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Note AB Capturing the rare long-period (LP) volcanic earthquakes occurring in and near Long Valley caldera, California, is important to ongoing volcanic-hazards monitoring. It is difficult, however, because LP events are weak, emergent, and almost devoid of energy above a few hertz. Automatic systems designed for tectonic earthquakes routinely fail to capture LP events. We applied a PC-based teleseism-specific event-detection computer program to capturing these events. Retuning the software for LP events involved only changing parameters originally designed for change in this algorithm. Our retuned algorithm has captured every known LP event at Long Valley from October 1992 through the end of 1994. We monitored up to 16 stations known to produce good records of LP events, saving those events that triggered enough of these stations (typically 10 of 16) within a specified time window. The principal difficulty has been the algorithm's sensitivity to regional earthquakes, which have waveforms similar to LP events. During our test, the 1992 Landers, 1994 Northridge, and 1994 Double Springs Flat (Nevada) earthquakes each have swamped the detector, requiring careful, active management of PC disk resources. The efficacy of this retuned algorithm and the poor performance of tectonic-earthquake detectors during some volcanic emergencies make this algorithm an attractive candidate for volcano monitoring. RP EVANS, JR (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 7 TC 4 Z9 5 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1995 VL 85 IS 5 BP 1518 EP 1522 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TA774 UT WOS:A1995TA77400024 ER PT J AU CROVELLI, RA AF CROVELLI, RA TI ENVIRONMENTAL PROBABILISTIC QUANTITATIVE ASSESSMENT METHODOLOGIES SO COMPUTERS & GEOSCIENCES LA English DT Article DE ANALYTIC PROBABILITY SYSTEMS; QUANTITATIVE POLLUTION ESTIMATION; LANDFILL REFUSE; ANALOGOUS METHODS ID PROGRAM AB Probabilistic methodologies developed originally for one area of application may be applicable in another area. Therefore, it is extremely important to communicate across disciplines. Of course, a physical reinterpretation is necessary and perhaps some modification of the methodology. This seems to be the situation in applying resource assessment methodologies as environmental are presented methodologies. In this paper, four petroleum resources assessment methodologies are presented as possible pollution assessment methodologies, even though petroleum as a resources is desirable, whereas pollution is undesirable. It is ironic that oil as a precious resource in the ground can become a serious pollutant as a spill in the ocean. There are similarities in both situations where the quality of undiscovered crude oil and natural gas resources, and the quality of a pollutant or contaminant are to be estimated. Obviously, we re interested in making a quantitive assessment in order to answer the question, ''How much material is there?'' For situations in which there are a lack of statistical data, risk analysis is used rather than classical statistical analysis. That is, a relatively subjective evaluation is made rather than an evaluation based on random sampling which may be impossible. Hence, probabilistic quantitative assessment methodologies are needed for the risk analysis. A methodology is defined in this paper to consist of a probability model and a probabilistic method, where the method is used to solve the model. The following four basic types of probability models are considered: (1) direct assessment, (2) accumulation size, (3) volumetric yield, and (4) reservoir engineering. Three of the four petroleum resources assessment methodologies were written as microcomputer systems, viz., TRIAGG for direct assessment, APPAS for accumulation size, and FASPU for reservoir engineering. A fourth microcomputer system termed PROBDIST supports the three assessment systems. TRIAGG is the simplesr assessment system, and therefore, more general in application. APRAS is more complex, and FASPU is the most complex. TRIGG and PROBDIST are completely generic, or general probability systems, in that they are not dependent on the physical context, only on the structure. Hence, they would require no modifications for pollution assessment application. APRAS would require some modification, and FASPU even more; however, many of the ideas of both would be applicable. The three assessment systems have different probability models but the same type of probabilistic method. The type of probabilistic method is analytic probability theory instead of Monte Carlo simulation. Among the advantages of the analytic method are its computational speed and flexibility, making it ideal for a microcomputer. All four OBM-PC compatible microcomputer systems are available from the U.S. Geological Survey Books and Open-File Reports Section. RP CROVELLI, RA (reprint author), US GEOL SURVEY,BOX 25046,MS-971,DENVER,CO 80225, USA. NR 13 TC 0 Z9 0 U1 3 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0098-3004 J9 COMPUT GEOSCI JI Comput. Geosci. PD OCT PY 1995 VL 21 IS 8 BP 971 EP 984 DI 10.1016/0098-3004(95)00034-6 PG 14 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA TC683 UT WOS:A1995TC68300007 ER PT J AU CHAMBERS, SM AF CHAMBERS, SM TI SPATIAL STRUCTURE, GENETIC-VARIATION, AND THE NEIGHBORHOOD ADJUSTMENT TO EFFECTIVE POPULATION-SIZE SO CONSERVATION BIOLOGY LA English DT Note C1 US FISH & WILDLIFE SERV,DIV ENDANGERED SPECIES,ALBUQUERQUE,NM 87103. NR 31 TC 10 Z9 10 U1 0 U2 6 PU BLACKWELL SCIENCE PUBL INC CAMBRIDGE PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 1995 VL 9 IS 5 BP 1312 EP 1315 DI 10.1046/j.1523-1739.1995.9051312.x PG 4 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA TB449 UT WOS:A1995TB44900047 ER PT J AU WALTER, MJ SISSON, TW PRESNALL, DC AF WALTER, MJ SISSON, TW PRESNALL, DC TI A MASS PROPORTION METHOD FOR CALCULATING MELTING REACTIONS AND APPLICATION TO MELTING OF MODEL UPPER-MANTLE LHERZOLITE SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID PHASE-RELATIONS; RIDGE BASALTS; OCEAN-RIDGE; PERIDOTITE; CRYSTALLIZATION; GENERATION; ORIGIN; MAGMA AB We present a method for calculating quantitative melting reactions in systems with multiple solid solutions that accounts for changes in the mass proportions of phases between two points at different temperatures along a melting curve. This method can be applied to any data set that defines the phase proportions along a melting curve. The method yields the net change in mass proportion of all phases for the chosen melting interval, and gives an average reaction for the melting path. Instantaneous melting reactions can be approximated closely by choosing sufficiently small melting intervals. As an application of the method, reactions for melting of model upper mantle peridotite are calculated using data from the system CaO-MgO-Al2O3-SiO2-Na2O (CMASN) over the pressure interval 0.7-3.5 GPa. Throughout almost this entire pressure range, melting of model Iherzolite involves the crystallization of one or more solid phases, and is analogous to melting at a peritectic invariant point, In addition, we show that melting reactions for small melting intervals(< 5%) along the solidus of mantle peridotite are significantly different from those calculated for large melting intervals. For large melting intervals (> 10%), reaction stoichiometries calculated in CMASN are usually in good agreement with those available for melting of natural peridotite, The coefficients of melting reactions calculated from this method can be used in equations that describe the behavior of trace elements during melting. We compare results from near-fractional melting models using (1) melting reactions and rock modes from CMASN, and (2) constant reactions representative of those used in the literature. In modeling trace element abundances in melt, significant differences arise for some elements at low degrees of melting(< 10%). In modeling element abundances in the residue, differences increase with increase in degree of melting. Reactions calculated along the model Iherzolite solidus in CMASN are the only ones available at present for small degrees of melting so we recommend them for accurate trace element modeling of natural lherzolite. C1 CARNEGIE INST WASHINGTON,GEOPHYS LAB,WASHINGTON,DC 20015. CTR HIGH PRESSURE RES,WASHINGTON,DC 20015. US GEOL SURVEY,MENLO PK,CA 94025. UNIV TEXAS,CTR LITHOSPHER STUDIES,MAGMAL LAB,RICHARDSON,TX 75083. NR 36 TC 70 Z9 71 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT PY 1995 VL 135 IS 1-4 BP 77 EP 90 DI 10.1016/0012-821X(95)00148-6 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TC786 UT WOS:A1995TC78600006 ER PT J AU SHARMA, M WASSERBURG, GJ PAPANASTASSIOU, DA QUICK, JE SHARKOV, EV LAZKO, EE AF SHARMA, M WASSERBURG, GJ PAPANASTASSIOU, DA QUICK, JE SHARKOV, EV LAZKO, EE TI HIGH ND-143/ND-144 IN EXTREMELY DEPLETED MANTLE ROCKS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID OCEAN-RIDGE BASALTS; SAMAIL OPHIOLITE; SM-ND; RB-SR; PERIDOTITES; EARTH; GARNET; CRUST; GEOCHEMISTRY; SYSTEMATICS AB Using an iron hydroxide precipitation to concentrate the rare earth elements it was possible to obtain precise Nd isotopic data on ultramafic rocks. Four samples of unserpentinized harzburgite from the Voykar ophiolite, Polar Urals, are characterized by extreme depletion in fertile components including light rare earth elements down to similar to 1.7 ppb Nd. These samples have f(Sm/Nd) values > +1 and epsilon(Nd)(0) values ranging from +21 to +47, the highest ever measured in terrestrial whole rock samples. Combined epsilon(Nd) and epsilon(Sr) values of the ultramafic and mafic rocks and a leach indicate that alteration from seawater and/or groundwater is orders of magnitude less than required to produce a detectable change in the epsilon(Nd) values even in samples with > 50% serpentine. Three of the harzburgites plot on a Sm-Nd whole rock array along with samples of dunite, websterite, gabbro and diabase from the ophiolite. The slope of the array corresponds to an age of 387 +/- 34 Ma and an initial epsilon(Nd) = +8.6 +/- 1.8. These results indicate that the oceanic crustal rocks and the harzburgites are complementary and come from a MORE source. While the linear Sm-147/Nd-144-/Nd-143/Nd-144 correlation is consistent with this model, one sample of harzburgite is far removed from the array, indicating the presence of older, depleted mantle material that is unrelated to the crustal section, This must be locally available in the upper mantle for tectonic occlusion during obduction of the ophiolite, Alternatively, this ''aberrant'' sample may represent the original ultrabasic section from older basalt extraction that was permeated by basalts derived from much deeper layers that provided the Voykar ophiolite crust. The major-element and low-REE-compositions of the Voykar harzburgites can be formed by progressive extraction of melt from an undepleted mantle protolith with the requirement that melt separation began in the garnet Iherzolite stability field. The extreme chemical and isotopic characteristics of the Voykar harzburgites demonstrate that extraction of partial melt can generate an upper mantle with highly variable epsilon(Nd) and very low Nd concentrations. The potential presence of large amounts of such material in the upper mantle poses an intriguing geochemical problem in that its bulk isotopic signature may not be detectably expressed in basalts, which are dominated by sources with higher average Nd concentrations and much lower epsilon(Nd) and f(Sm/Nd). C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RUSSIAN ACAD SCI,IGEM,MOSCOW 109017,RUSSIA. RP SHARMA, M (reprint author), CALTECH,DIV GEOL & PLANETARY SCI,CHARLES ARMS LAB,LUNAT ASYLUM,PASADENA,CA 91125, USA. RI WASSERBURG, GERALD /F-6247-2011 NR 54 TC 52 Z9 53 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT PY 1995 VL 135 IS 1-4 BP 101 EP 114 DI 10.1016/0012-821X(95)00150-B PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TC786 UT WOS:A1995TC78600008 ER PT J AU WOODWARD, RL MOLNAR, P AF WOODWARD, RL MOLNAR, P TI LATERAL HETEROGENEITY IN THE UPPER-MANTLE AND SS-S TRAVEL-TIME INTERVALS FOR SS-RAYS REFLECTED FROM THE TIBETAN PLATEAU AND ITS SURROUNDINGS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID WAVE VELOCITY STRUCTURE; TECTONIC IMPLICATIONS; STRUCTURE BENEATH; TIME RESIDUALS; INDIAN SHIELD; INVERSION; ANOMALIES; EARTH; CONSTRAINTS; EARTHQUAKES AB We report large differences between measured and calculated intervals between arrival times of S waves and SS phases whose bounce points lie beneath different parts of the Tibetan Plateau and its surroundings. When compared with traveltimes calculated from the laterally homogeneous Preliminary Reference Earth Model (PREM), the shortest intervals between SS and S correspond to paths with SS reflected from the Karakorum and westernmost parts of the Tibetan Plateau and Himalaya. Comparable, but more scattered, SS - S residuals characterize paths with SS reflected beneath southern Tibet. The longest such intervals typify paths with SS reflected beneath north central Tibet. If upper mantle structure near the bounce points of SS causes these average apparent advances of 7 s and delays of up to 6 s, then these data suggest that material with high S-wave speeds underlie the Karakorum, and low S-wave speeds underlie north central Tibet, a result that concurs with other seismological observations. If such high- or low-speed regions were confined to the upper 250 km of the mantle, they would imply a difference on the order of 13% in S-wave speeds between these two regions. Heterogeneity in the lower mantle, inferred in part from these data, can, however, account for part of the large variation in residuals that we observe. After correcting for large-scale heterogeneity in the upper and lower mantle, roughly 9 s of difference persists, which would correspond to average differences of 9% or 0.4 km/s in S-wave speeds in the upper 250 km of the mantle beneath these regions. Only at subduction zones can one find such a difference in average S-wave speeds in the mantle beneath regions only 500-1000 km apart, suggesting that dynamic flow in the mantle presently occurs in the upper mantle beneath the Tibetan Plateau. This difference supports the contention that small-scale convection occurs beneath the Tibetan Plateau. C1 MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. UNIV OXFORD,DEPT EARTH SCI,OXFORD OX1 3PR,ENGLAND. RP WOODWARD, RL (reprint author), US GEOL SURVEY,ALBUQUERQUE SEISMOL LAB,ALBUQUERQUE,NM, USA. NR 34 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT PY 1995 VL 135 IS 1-4 BP 139 EP 148 DI 10.1016/0012-821X(95)00154-5 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TC786 UT WOS:A1995TC78600011 ER PT J AU PEVERLY, JH SURFACE, JM WANG, TG AF PEVERLY, JH SURFACE, JM WANG, TG TI GROWTH AND TRACE-METAL ABSORPTION BY PHRAGMITES-AUSTRALIS IN WETLANDS CONSTRUCTED FOR LANDFILL LEACHATE TREATMENT SO ECOLOGICAL ENGINEERING LA English DT Article DE IRON; LEAD; COPPER; ROOT PLAQUE; EVAPOTRANSPIRATION; X-RAY; PHRAGMITES AUSTRALIS; GROWTH RATE ID CAV TRIN; OXYGEN AB Phragmites australis (common reed) grew well in the presence of high concentrations of NH4+-N (300 mg/l), BOD (300 mg/l), Fe (30 mg/l), Mn (1.5 mg/l) and K (500 mg/l). Other metals were not particularly elevated with the pH of the landfill leachate being 7-7.2. Reed standing crop continued to increase in the two years after leachate applications began, ranging to about 1100, 100, and 1000 g/m(2) dry wt. for shoots, roots and rhizomes, respectively. Nutrient elements like N, K, Ca, and Mg were absorbed to normally sufficient levels, while tissue P was low at 0.04%. Metals were not translocated to and accumulated by shoots or rhizomes, but exhibited elevated levels in roots. Fe, Cu, Zn, Pb, and Cd were at levels of 3700, 65, 45, 12 and 0.2 mg/kg respectively, but the roots acted as effective filters for transport of metals to the shoots and rhizomes. Only P and Zn accumulation by plants approached total amounts in leachate entering the constructed beds. SEM and X-ray microanalysis showed Fe accumulation on root surfaces, with Fe and other metals at lower concentrations inside the root tissue. The rhizosphere may provide a particularly effective, locally oxidized environment for metal precipitation and adsorption outside the root. C1 US GEOL SURVEY,ITHACA,NY 14850. RP PEVERLY, JH (reprint author), CORNELL UNIV,DEPT SOIL CROP & ATMOSPHER SCI,ITHACA,NY 14853, USA. NR 10 TC 110 Z9 123 U1 0 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD OCT PY 1995 VL 5 IS 1 BP 21 EP 35 DI 10.1016/0925-8574(95)00018-E PG 15 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA TB359 UT WOS:A1995TB35900004 ER PT J AU SANFORD, WE STEENHUIS, TS SURFACE, JM PEVERLY, JH AF SANFORD, WE STEENHUIS, TS SURFACE, JM PEVERLY, JH TI FLOW CHARACTERISTICS OF ROCK-REED FILTERS FOR TREATMENT OF LANDFILL LEACHATE SO ECOLOGICAL ENGINEERING LA English DT Article DE CONSTRUCTED WETLANDS; PREFERENTIAL FLOW; HYDROLOGY; WASTE-WATER TREATMENT; TRACERS ID ROOT-ZONE METHOD; WASTE-WATER; SCALE AB To characterize the flow patterns of wastewater through subsurface-flow rock-reed filters, a combination of tracer studies and specific conductance measurements were used. Neither the tracer study nor the specific conductance measurements alone provided the necessary information to understand the flow of wastewater through the system. However, the data taken together indicate that preferential flow occurred due to density effects and surface flow. In gravel substrates, dense wastewater flowed beneath the less dense rainwater and influent, resulting in a decrease in the residence time. Sand-and-gravel substrates, which experienced a great deal of surface flow as a result of clogging, were shown to have very little, if any, flow through the subsurface. The results of this study indicate that both preferential and overland flow should be taken into account for the proper design of rock-reed filters. C1 UNIV TENNESSEE,DEPT CIVIL & ENVIRONM ENGN,KNOXVILLE,TN. CORNELL UNIV,DEPT AGR & BIOL ENGN,ITHACA,NY 14853. US GEOL SURVEY,DIV WATER RESOURCES,ITHACA,NY. CORNELL UNIV,DEPT SOIL CROP & ATMOSPHER SCI,ITHACA,NY 14853. RP SANFORD, WE (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS-6352 BLDG,OAK RIDGE,TN 37831, USA. RI Sanford, William/F-7380-2016 OI Sanford, William/0000-0001-9085-1367 NR 13 TC 12 Z9 14 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD OCT PY 1995 VL 5 IS 1 BP 37 EP 50 DI 10.1016/0925-8574(95)00012-8 PG 14 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA TB359 UT WOS:A1995TB35900005 ER PT J AU OWEN, DE OTTON, JK AF OWEN, DE OTTON, JK TI MOUNTAIN WETLANDS - EFFICIENT URANIUM FILTERS - POTENTIAL IMPACTS SO ECOLOGICAL ENGINEERING LA English DT Article DE ENVIRONMENTAL IMPACT; ENRICHMENT; FILTRATION FUNCTION; METAL; URANIUM; WATER QUALITY ID HUMIC ACIDS; BIOSORPTION; URANYL; WATER; ROCK AB Wetlands are common in montane and subalpine settings in the Rocky Mountains, Sierra Nevada, and other mountainous regions of the western U.S. Because they are efficient filters, many contain anomalous concentrations of uranium and other metals. Sorption by organic matter, complexing of the uranyl ion, (UO2) (2+), with humic and fulvic acids, and action by bacteria has produced geochemical enrichment factors greater than 10000 to 1 between peat and uranium-bearing waters. Sediments in 67 of 145 Colorado wetlands sampled by the U.S. Geological Survey contain moderate (20 ppm) or greater concentrations of uranium (some as high as 3000 ppm) based on dry weight. The proposed maximum contaminant level (MCL) for uranium in drinking water is 20 mu g/l or 20 ppb. By comparison, sediments in many of these wetlands contain 3 to 5 orders of magnitude more uranium than the proposed MCL. Wetlands near the workings of old mines (widespread in Colorado and other areas) may be trapping any number of additional metals/elements including Cu, Pb, Zn, As and Ag. Anthropogenic disturbances and natural changes may release uranium and other loosely bound metals presently contained in wetland sediments. Draining of wetlands with resulting oxidation of organic-rich sediments, acidification, and other environmental and geochemical changes may free relatively high concentrations of metals that have accumulated for thousands of years in the organic-rich sediments. Destruction of wetlands eliminates the natural filtration function which serves to protect water quality. RP OWEN, DE (reprint author), US GEOL SURVEY,MS-939 DFC,DENVER,CO 80225, USA. NR 49 TC 30 Z9 30 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD OCT PY 1995 VL 5 IS 1 BP 77 EP 93 DI 10.1016/0925-8574(95)00013-9 PG 17 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA TB359 UT WOS:A1995TB35900007 ER PT J AU PETTY, JD HUCKINS, JN ORAZIO, CE LEBO, JA POULTON, BC GALE, RW CHARBONNEAU, CS KAISER, EM AF PETTY, JD HUCKINS, JN ORAZIO, CE LEBO, JA POULTON, BC GALE, RW CHARBONNEAU, CS KAISER, EM TI DETERMINATION OF WATERBORNE BIOAVAILABLE ORGANOCHLORINE PESTICIDE-RESIDUES IN THE LOWER MISSOURI RIVER SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SEMIPERMEABLE-MEMBRANE DEVICES; ORGANIC CONTAMINANTS; GREAT-LAKES; ACCUMULATION; HYDROCARBONS; CHEMICALS; WATERS; FISH; RISK AB The semipermeable membrane device (SPMD) technology, developed and patented by the National Biological Service's (NBS) Midwest Science Center (MSG), was used to determine the presence of bioavailable organochlorine (OC) pesticides in the water of the main stem Missouri River. Specifically, the SPMDs were deployed for 28 days at five main stem sites-Sioux City, IA; Nebraska City, NE; Kansas City, MO (above metropolitan area); Glasgow, MO; and Hermann, MO. In general, OCs were present at all sites. Of all targeted analytes, the chlordane components, heptachlor expoxide, toxaphene, and dieldrin were generally present at the highest concentrations. For example, heptachlor epoxide ranged from a high of 180 ng/sample at Hermann to a low of 22 ng/sample at Sioux City, while dieldrin ranged from a high of 800 ng/sample at Glasgow to a low of 64 ng/sample at Sioux City. Replicate (n = 4) SPMD samplers sequestered similar quantities (typical CV = 10-35%) of each OC pesticide. The sequestered residues represent an estimation of bioavailable (by respiration process) or dissolved OCs present in the main stem of the Missouri River. C1 US FISH & WILDLIFE SERV, COLUMBIA, MO 65201 USA. UNIV MISSOURI, DEPT CHEM, COLUMBIA, MO 65211 USA. RP PETTY, JD (reprint author), NATL BIOL SERV, 4200 NEW HAVEN RD, COLUMBIA, MO 65201 USA. NR 34 TC 51 Z9 55 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1995 VL 29 IS 10 BP 2561 EP 2566 DI 10.1021/es00010a016 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA RY885 UT WOS:A1995RY88500035 PM 22191955 ER PT J AU KVENVOLDEN, KA HOSTETTLER, FD CARLSON, PR RAPP, JB THRELKELD, CN WARDEN, A AF KVENVOLDEN, KA HOSTETTLER, FD CARLSON, PR RAPP, JB THRELKELD, CN WARDEN, A TI UBIQUITOUS TAR BALLS WITH A CALIFORNIA-SOURCE SIGNATURE ON THE SHORELINES OF PRINCE WILLIAM SOUND, ALASKA SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CRUDE OILS; STERANES; MATURATION; TERPANES AB Although the shorelines of Prince William Sound still bear traces of the 1989 Exxon Valdez oil spill, most of the flattened tar balls that can be found today on these shorelines are not residues of Exxon Valdez oil. Instead, the carbon-isotopic and hydrocarbon-biomarker signatures of 61 tar ball samples, collected from shorelines throughout the northern and western parts of the sound, are all remarkably similar and have characteristics consistent with those of oil products that originated from the Monterey Formation source rocks of California. The carbon-isotopic compositions of the tar balls are all closely grouped (delta(13)C(PDB) = -23.7 +/- 0.2 parts per thousand), within the range found in crude oils from those rocks, but are distinct from isotopic compositions of 28 samples of residues from the Exxon Valdez oil spill (delta(13)C(PDB) = -29.4 +/- 0.1 parts per thousand). Likewise, values for selected biomarker ratios in the tar balls are all similar but distinct from values of residues from the 1989 oil spill. Carbon-isotopic and biomarker signatures generally relate the tar balls to oil products used in Alaska before similar to 1970 for construction and pavements. How these tar balls with such similar geochemical characteristics became so widely dispersed throughout the northern and western parts of the sound is not known with certainty, but the great 1964 Alaska earthquake was undoubtedly an important trigger, causing spills from ruptured storage facilities of California-sourced asphalt and fuel oil into Prince William Sound. C1 US GEOL SURVEY, DENVER, CO 80225 USA. RP KVENVOLDEN, KA (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 999, MENLO PK, CA 94025 USA. NR 24 TC 85 Z9 87 U1 4 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1995 VL 29 IS 10 BP 2684 EP 2694 DI 10.1021/es00010a033 PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA RY885 UT WOS:A1995RY88500052 PM 22191972 ER PT J AU TORIGOYEKITA, N MISAWA, K TATSUMOTO, M AF TORIGOYEKITA, N MISAWA, K TATSUMOTO, M TI U-TH-PB AND SM-ND ISOTOPIC SYSTEMATICS OF THE GOALPARA UREILITE - RESOLUTION OF TERRESTRIAL CONTAMINATION - REPLY SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Note ID WESTERN UNITED-STATES; MESOZOIC CRUSTAL STRUCTURE; CONTINENTAL-CRUST; RB-SR; PENINSULAR RANGES; TERTIARY GRANITE; SIERRA-NEVADA; NEODYMIUM; ORIGIN; PROVENANCE C1 KOBE UNIV,DEPT EARTH & PLANETARY SCI,NADA KU,KOBE 657,JAPAN. US GEOL SURVEY,MS 963,DENVER,CO 80225. RP TORIGOYEKITA, N (reprint author), GEOL SURVEY JAPAN,HIGASHI 1-1-3,TSUKUBA,IBARAKI 305,JAPAN. RI Kita, Noriko/H-8035-2016 OI Kita, Noriko/0000-0002-0204-0765 NR 30 TC 7 Z9 7 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD OCT PY 1995 VL 59 IS 19 BP 4087 EP 4091 DI 10.1016/0016-7037(95)00297-D PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RY653 UT WOS:A1995RY65300017 ER PT J AU VIDALE, JE DING, XY GRAND, SP AF VIDALE, JE DING, XY GRAND, SP TI THE 410-KM-DEPTH DISCONTINUITY - A SHARPNESS ESTIMATE FROM NEAR-CRITICAL REFLECTIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UPPER-MANTLE STRUCTURE; STRUCTURE BENEATH; AUSTRALIA AB The abrupt increase in seismic velocity and density about 410 km below the surface of the Earth occurs at the depth where a phase change in olivine is expected [Akaogi et al., 1989; Katsura and Ito, 1989; Ringwood, 1969]. We have assembled recordings from 22 short-period seismometers in Washington and British Columbia of 35 nuclear explosions in Nevada. These data reveal relatively noise-free reflections from the ''410'' discontinuity. Most of the transition is completed within a depth interval of less than 10 km under the western United States. This result adds to the accumulating seismic evidence of a fairly sharp ''410'' transition. C1 UNIV TEXAS,AUSTIN,TX 78712. US GEOL SURVEY,MENLO PK,CA 94025. RI Grand, Stephen/B-4238-2011; Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 28 TC 33 Z9 33 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1995 VL 22 IS 19 BP 2557 EP 2560 DI 10.1029/95GL02663 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RX918 UT WOS:A1995RX91800002 ER PT J AU Bargar, KE Terry, ECKI Trusdell, FA AF Bargar, KE Terry, ECKI Trusdell, FA TI Fluid-inclusion evidence for past temperature fluctuations in the Kilauea East Rift Zone geothermal area, Hawaii SO GEOTHERMICS LA English DT Article DE Kilauea East Rift Zone; geothermal coreholes; fluid inclusions; hydrothermal alteration; past temperatures; Hawaii ID HYDROTHERMAL ALTERATION; MINERALS; ICELAND; SYSTEM AB Heating and freezing data were obtained for fluid inclusions in hydrothermal quartz, calcite, and anhydrite from several depths in three scientific observation holes drilled along the lower East Rift Zone of Kilauea volcano, Hawaii. Compositions of the inclusion fluids range from dilute meteoric water to highly modified sea water concentrated by boiling. Comparison of measured drill-hole temperatures with fluid-inclusion homogenization-temperature (Th) data indicates that only about 15% of the fluid inclusions could have formed under the present thermal conditions. The majority of fluid inclusions studied must have formed during one or more times in the past when temperatures fluctuated in response to the emplacement of nearby dikes and their subsequent cooling. The fluid-inclusion data indicate that past temperatures in SOH-4 well were as much as 64 degrees C hotter than present temperatures between 1000 and 1500 m depth and they were a maximum of 68 degrees C cooler than present temperatures below 1500 m depth. Similarly, the data show that past temperatures near the bottoms of SOH-1 and SOH-2 wells were up to 45 and 59 degrees C, respectively, cooler than the present thermal conditions; however, the remainder of fluid-inclusion Th values for these two drill holes suggests that the temperature's of the trapped waters were nearly the same as the present temperatures at these slightly shallower depths. Several hydrothermal minerals (erionite, mordenite, truscottite, smectite, chlorite-smectite, chalcedony, anhydrite, and hematite), occurring in the drill holes at higher temperatures than they are found in geothermal drill holes of Iceland or other geothermal areas, provide additional evidence for a recent heating trend. C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. US GEOL SURVEY,HAWAII VOLCANO OBSERV,HAWAII NATL PK,HI 96718. RP Bargar, KE (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 910,MENLO PK,CA 94025, USA. NR 62 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD OCT-DEC PY 1995 VL 24 IS 5-6 BP 639 EP 659 DI 10.1016/0375-6505(95)00034-8 PG 21 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA TP300 UT WOS:A1995TP30000004 ER PT J AU Coplen, TB AF Coplen, TB TI Reporting of stable hydrogen, carbon, and oxygen isotopic abundances - (Technical report) SO GEOTHERMICS LA English DT Article ID NATURAL-WATERS AB To eliminate possible confusion in the reporting of isotopic abundances on noncorresponding scales, the Commission on Atomic Weights and Isotopic Abundances recommended at the 37(th) General Assembly at Lisbon, Portugal that (i) H-2/H-1 relative ratios of all substances be expressed relative to VSMOW (Vienna Standard Mean Ocean Water) on a scale such that H-2/H-1 Of SLAP (Standard Light Antarctic Precipitation) is 0.572 times that of VSMOW, (ii) C-13/C-12 relative ratios of all substances be expressed relative to VPDB (Vienna Peedee belemnite) on a scale such that C-13/C-12 of NBS 19 carbonate is 1.00195 times that of VPDS, and (iii) O-18/O-16 ratios of all substances be expressed relative to either VSMOW or VPDB on scales such that O-18/O-16 of SLAP is 0.9445 times that of VSMOW. RP Coplen, TB (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 8 TC 24 Z9 24 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD OCT-DEC PY 1995 VL 24 IS 5-6 BP 708 EP 712 PG 5 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA TP300 UT WOS:A1995TP30000008 ER PT J AU FREEMAN, DC EMLEN, JM AF FREEMAN, DC EMLEN, JM TI ASSESSMENT OF INTERSPECIFIC INTERACTIONS IN PLANT-COMMUNITIES - AN ILLUSTRATION FROM THE COLD DESERT SALTBUSH GRASSLANDS OF NORTH-AMERICA SO JOURNAL OF ARID ENVIRONMENTS LA English DT Article DE SPECIES INTERACTION; COMPETITION; COLD DESERT; SALTBUSH; GRASSLANDS ID CRYPTOGAMIC SOIL CRUSTS; UTAH; POPULATION; ALLOCATION; PATTERNS AB Interspecific interactions influence both the productivity and composition of plant communities. Here, we propose new field procedures and analytical approaches for assessing interspecific interactions in nature and apply these procedures to the salt desert shrub grasslands of western Utah. Data were collected from two grazing treatments over a period of 2 years. The proposed equations were fairly consistent across both treatments and years. In addition to illustrating how to assess interspecific interactions within a community, we also develop a new approach for projecting the community composition as a result of some alteration, i.e. increase or decrease in the abundance of one or more species. Results demonstrate competition both within and between plant life-form groups. While introduced annuals were found to depress profoundly the likelihood of perennial plants replacing themselves, perennials had little influence on annuals. Thus, as native perennials die, they are more likely to be replaced by perennials than for the reverse to occur. Our results suggest that unless conditions change, these communities will become increasingly dominated by introduced annuals. (C) 1995 Academic Press Limited C1 USN STN,US FISH & WILDLIFE SERV,SEATTLE,WA 98115. RP FREEMAN, DC (reprint author), WAYNE STATE UNIV,DEPT BIOL SCI,DETROIT,MI 48202, USA. NR 21 TC 18 Z9 19 U1 1 U2 4 PU ACADEMIC PRESS (LONDON) LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0140-1963 J9 J ARID ENVIRON JI J. Arid. Environ. PD OCT PY 1995 VL 31 IS 2 BP 179 EP 198 PG 20 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA RZ577 UT WOS:A1995RZ57700005 ER PT J AU KOMADA, N WESTRUM, EF HEMINGWAY, BS ANOVITZ, LM AF KOMADA, N WESTRUM, EF HEMINGWAY, BS ANOVITZ, LM TI THERMODYNAMIC PROPERTIES OF 2 IRON SILICATES - HEAT-CAPACITIES OF DEERITE FROM THE TEMPERATURE 10K TO 700 K AND OF GRUNERITE FROM 10 K TO 1000 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID MAGNETIC-PROPERTIES; CRITICAL-BEHAVIOR; SHEET SILICATES; LAYER MINERALS; ISING MODELS; SCALE AB Heat-capacity measurements were made on deerite and on grunerite with an adiabatic calorimetric system from the temperature 10 K to 350 K and by d.s.c. in the super-ambient region. Slight Schottky-like and bell-shaped anomalies appear near T = 16 K and 34 K in the deerite heal-capacity curve. The smaller than expected magnetic susceptibility and Mossbauer spectral changes at T > 210 K were interpreted as a thermally activated electron-delocalization mechanism in the deerite sample and yet another deerite sample by adjusting for anharmonicity and resolving the small excess heat capacities by the Komada-Westrum approach. A sharp anomaly centered at T = 35.5 K was observed in the heat capacity of grunerite curve. Measured values of C-y,C-m/R, {S-m degrees(T') - S-m degrees(10 K)}/R, and -{Phi(m) degrees(T') - Phi(m) degrees(10 K)}/R at T' = 298.15 K for deerite are 94.55, 95.21, and -43.50, respectively, where C-y,C-m denotes molar heat capacity, S-m degrees standard molar entropy, H-m degrees standard molar enthalpy, and where Phi(m) degrees = Delta(0)(T)S(m) degrees - Delta(0)(T)H(m) degrees/T. The corresponding values for grunerite are 82.38, 83.98, and -39.69, respectively. The standard molar entropy at T = 298.15 K, after adjusting to the end-member compositions, is 96.39 . R for deerite (Fe6Fe3O3)-Fe-II-O-III(Si6O17)(OH)(5) except for possible residual S-m at T-->0. That for grunerite Fe7Si8O22(OH)(2) is 90.01 . R, except for possible magnetic excess entropy at T < 10 K. (C) 1995 Academic Press Limited C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. US GEOL SURVEY,RESTON,VA 22092. UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. NR 56 TC 9 Z9 9 U1 0 U2 3 PU ACADEMIC PRESS (LONDON) LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD OCT PY 1995 VL 27 IS 10 BP 1097 EP 1118 DI 10.1006/jcht.1995.0115 PG 22 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA RY236 UT WOS:A1995RY23600005 ER PT J AU KOMADA, N WESTRUM, EF HEMINGWAY, BS ZOLOTOV, MY SEMENOV, YV KHODAKOVSKY, IL ANOVITZ, LM AF KOMADA, N WESTRUM, EF HEMINGWAY, BS ZOLOTOV, MY SEMENOV, YV KHODAKOVSKY, IL ANOVITZ, LM TI THERMODYNAMIC PROPERTIES OF SODALITE AT TEMPERATURES FROM 15 K TO 1000 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID THERMAL-EXPANSION; MINERALS AB The heat capacity of sodalite was measured with a computerized adiabatic calorimetric system at temperatures from 15 K to 350 K and with a d.s.c. from 340 K to 1000 K. No anomalies were observed over the entire range except for a peak at T approximate to 250 K associated with fusion of NaCl(aq) fluid inclusions. The temperature of the spontaneous freezing of the fluid inclusions was remarkably reproducible, and the metastable liquid phase persisted from T = 250 K to 200 K upon cooling. The standard molar entropy for the end-member composition: Na-8(Al6Si6O24)Cl-2 is 102.0 . R at T = 298.15 K. The enthalpy of solution of sodalite was measured in 2PbO . B2O3(I) at T = 973 K with a Calvet-type calorimeter. The value of Delta(sol)H(m) degrees(973 K) is (58.98 +/- 0.71). 10(3) . R . K. The calculated standard molar enthalpy and standard molar Gibbs free energy of formation for Na(Al6Si6O24)Cl-2 are -(1618.6 +/- 1.9) . 10(3) . R . K and -(1527.9 +/- 2.0) . 10(3) . R . K, respectively. (C) 1995 Academic Press Limited C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. US GEOL SURVEY,RESTON,VA 22092. RUSSIAN ACAD SCI,VERNADSKY INST GEOCHEM & ANALYT CHEM,MOSCOW,RUSSIA. UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. OI Anovitz, Lawrence/0000-0002-2609-8750 NR 50 TC 14 Z9 14 U1 1 U2 2 PU ACADEMIC PRESS (LONDON) LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD OCT PY 1995 VL 27 IS 10 BP 1119 EP 1132 DI 10.1006/jcht.1995.0116 PG 14 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA RY236 UT WOS:A1995RY23600006 ER PT J AU CHEN, CL AF CHEN, CL TI FREE-SURFACE STABILITY-CRITERION AS AFFECTED BY VELOCITY DISTRIBUTION SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID FLOW STABILITY AB This paper examines how the velocity distribution of flow in open channels affects the kinematic and dynamic wave velocities, from which the various forms of the Vedernikov number (V) can be formulated. When V > 1, disturbances created in open-channel flow will amplify in the form of roll waves; when V < 1, some (though not all) disturbances will attenuate. The specific state of flow at V = 1 represents a limiting case of neutral stability. A study of the Vedernikov stability criterion (V (sic) 1) reveals that it can be readily deduced within the framework of the kinematic and dynamic wave theories by comparing the kinematic wave velocity to the corresponding dynamic wave velocity. This in effect recasts V as the ratio of the kinematic and dynamic wave velocities. This ratio further proves equivalent to F/F-s, the ratio of the Froude number (F) to the stability limit for the Froude number (F-s). Thus, distinguishing among theoretical F-s-values for laminar and turbulent flows with various velocity distributions enables one to evaluate the role that the velocity distribution plays in the formulation of the Vedernikov stability criterion. RP CHEN, CL (reprint author), US GEOL SURVEY,DIV WATER RESOUR,345 MIDDLEFIELD RD,MS496,MENLO PARK,CA 94025, USA. NR 44 TC 7 Z9 7 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD OCT PY 1995 VL 121 IS 10 BP 736 EP 743 DI 10.1061/(ASCE)0733-9429(1995)121:10(736) PG 8 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA RW509 UT WOS:A1995RW50900007 ER PT J AU LEAHY, PP AF LEAHY, PP TI GROUNDWATER SAMPLING - PREFACE SO JOURNAL OF HYDROLOGY LA English DT Editorial Material RP LEAHY, PP (reprint author), US GEOL SURVEY,ASSESSMENT PROGRAM,959 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD OCT PY 1995 VL 171 IS 3-4 BP 217 EP 218 DI 10.1016/0022-1694(95)90031-4 PG 2 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RV895 UT WOS:A1995RV89500001 ER PT J AU WILSON, CJN HOUGHTON, BF MCWILLIAMS, MO LANPHERE, MA WEAVER, SD BRIGGS, RM AF WILSON, CJN HOUGHTON, BF MCWILLIAMS, MO LANPHERE, MA WEAVER, SD BRIGGS, RM TI VOLCANIC AND STRUCTURAL EVOLUTION OF TAUPO VOLCANIC ZONE, NEW-ZEALAND - A REVIEW SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Review ID KERMADEC ISLAND-ARC; NORTH-ISLAND; TEPHRA HORIZONS; GLASS SHARDS; HAVRE TROUGH; ISOTOPE DATA; SW PACIFIC; MAGMA; ERUPTION; ORIGIN AB The Taupo Volcanic Zone (TVZ) in the central North Island is the main focus of young volcanism in New Zealand. Andesitic activity started at c. 2 Ma, joined by voluminous rhyolitic (plus minor basaltic and dacitic) activity from c. 1.6 Ma. The TVZ is c. 300 km long (200 km on land) and up to 60 km wide, as defined by vent positions and caldera structural boundaries. The total volume of TVZ volcanic deposits is uncertain because a sub-volcanic basement has not been identified, but present data suggest bulk volumes of 15-20,000 km(3), and that faulted metasediments form most of the immediate subvolcanic basement. Rhyolite (greater than or equal to 15,000 km(3), bulk volume, typically 70-77% SiO2) is the dominant magma erupted in the TVZ (mostly as caldera forming ignimbrite eruptions), andesite is an order of magnitude less abundant,and basalt and dacite are minor in volume (< 100 km(3) each). The history of the TVZ is here divided into 'old TVZ' from 2.0 Ma to 0.34 Ma, and 'young TVZ' from 0.34 Ma onwards, separated by the Whakamaru eruptions, which obscured much of the evidence for older activity within the zone. The TVZ shows a pronounced segmentation into northeastern and southwestern andesite-dominated extremities with composite cones and no calderas, and a central 125-km-long rhyolite-dominated segment. Eight rhyolitic caldera centres have so far been identified in the central segment, of which two (Mangakino and Kapenga) are composite features, and more centres will probably be delineated as further data accumulate. These centres account for 34 inferred caldera-forming ignimbrite eruptions, in the c. 1.6-Ma lifetime of the central TVZ. The modern central TVZ is the most frequently active and productive silicic volcanic system on Earth, erupting rhyolite at c. 0.28 m(3) s(-1), and available information suggests this has been so for at least the past 0.34 Ma. The rhyolites show no major compositional changes with time, though the extent of magma chamber zonation may have changed with the incoming of rifting and crustal extension in the past c. 0.9 Ma. Within the central TVZ, non-rhyolitic compositions have been erupted apparently irregularly in time and space; in particular there is no evidence for a geographic separation of basalts from andesites. Between 0.9 and 0.34 Ma, a major episode of uplift affected areas around the TVZ, while at the same time the main focus of activity may have migrated eastwards within the TVZ accompanying rifting along the axis of the zone. The modern TVZ is rifting at rates between 7 and 18 mm a(-1) and restoration of the thin (15 km) 'crust' (V-p less than or equal to 6.1 km s(-1)) beneath the central TVZ to its pre-rifting thickness (25 km) implies that rifting at such rates may have begun only at c. 0.9 Ma. The TVZ is a rifted are, but its longitudinally segmented nature, high thermal flux and voluminous rhyolitic volcanism make it unique on Earth. C1 STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. UNIV CANTERBURY, DEPT GEOL SCI, CHRISTCHURCH, NEW ZEALAND. UNIV WAIKATO, DEPT EARTH SCI, HAMILTON, NEW ZEALAND. RP WILSON, CJN (reprint author), WAIRAKEI RES CTR, INST GEOL & NUCL SCI, PRIVATE BAG 2000, TAUPO, NEW ZEALAND. RI McWilliams, Michael/A-9548-2011; Wilson, Colin/E-9457-2011 OI McWilliams, Michael/0000-0002-4107-7069; Wilson, Colin/0000-0001-7565-0743 NR 152 TC 409 Z9 415 U1 5 U2 51 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 EI 1872-6097 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD OCT PY 1995 VL 68 IS 1-3 BP 1 EP 28 DI 10.1016/0377-0273(95)00006-G PG 28 WC Geosciences, Multidisciplinary SC Geology GA TF926 UT WOS:A1995TF92600002 ER PT J AU WARNOCK, N SCHWARZBACH, SE AF WARNOCK, N SCHWARZBACH, SE TI INCIDENTAL KILL OF DUNLIN AND KILLDEER BY STRYCHNINE SO JOURNAL OF WILDLIFE DISEASES LA English DT Note DE STRYCHNINE POISONING; SHOREBIRDS; CALIDRIS ALPINA; CHARADRIUS VOCIFERUS; CALIFORNIA; PESTICIDES AB Strychnine poisoning of 36 dunlin (Calidris alpina) and two killdeer (Charadrius uociferus) in Yolo County, California (USA) was documented from 11 to 17 December 1990. Birds were found dead on a field containing treated wheat seeds (337 mu g strychnine/g seed) in postures consistent with the known physiopathology of strychnine poisoning: rapid rigor mortis, wings folded over backs, straightened toes, and fecal material extruding from vents. Five dunlin and two killdeer were necropsied, and their crop and stomach contents were analyzed by high performance liquid chromatography for the presence of strychnine. The mean (+/- SD) actual unabsorbed strychnine concentration per amount stomach content for the five dunlin was 110 (+/- 108) mu g/g and for the two killdeer, 210 (+/- 109) mu g/g. Shorebirds have not been identified previously as victims of pesticides. C1 UNIV CALIF DAVIS,DAVIS,CA 95616. SAN DIEGO STATE UNIV,DEPT BIOL,SAN DIEGO,CA 92182. US FISH & WILDLIFE SERV,ECOL SERV,SACRAMENTO,CA 95825. NR 12 TC 11 Z9 11 U1 0 U2 3 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD OCT PY 1995 VL 31 IS 4 BP 566 EP 569 PG 4 WC Veterinary Sciences SC Veterinary Sciences GA TC335 UT WOS:A1995TC33500021 PM 8592394 ER PT J AU REYNOLDS, RE BLOHM, RJ NICHOLS, JD HINES, JE AF REYNOLDS, RE BLOHM, RJ NICHOLS, JD HINES, JE TI SPRING-SUMMER SURVIVAL RATES OF YEARLING VERSUS ADULT MALLARD FEMALES SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE ALBERTA; ANAS PLATYRHYNCHOS; MALLARD; MANITOBA; MORTALITY; NESTING; SASKATCHEWAN; SURVIVAL AB Knowledge of the timing, magnitude, and cause of mortality in wildlife populations is imperative for developing management strategies that protect or. improve the status of these populations. Age- and sex-specific population parameter estimates provide the most useful information for this purpose. Numerous studies have provided information about survival rates in mallards (Anas platyrhynchos), but little is known about age-related differences in female survival during the breeding period. We examined band-recovery data for female mallards banded in southern portions of Alberta, Saskatchewan, and Manitoba during spring and summer 1981-85. We used band-recovery models to test the hypothesis that yearling females would exhibit higher survival compared with that of older females during spring-summer. There was evidence (P = 0.08) that spring-summer survival rates of yearling females (0.728) were higher than that of older females (0.574). These findings support the hypothesis that age-specific differences in nesting behavior (e.g., later nest initiation and fewer nesting attempts by yearlings) influence losses to predators and are responsible for the difference in spring-summer survival. Management treatments that increase nest success, and consequently reduce the need for prolonged nesting, will increase mallard survival during spring-summer. C1 US FISH & WILDLIFE SERV,ARLINGTON,VA 22203. NATL BIOL SERV,PATUXENT ENVIRONM SCI CTR,LAUREL,MD 20708. RP REYNOLDS, RE (reprint author), US FISH & WILDLIFE SERV,1500 CAPITOL AVE,BISMARCK,ND 58501, USA. NR 18 TC 25 Z9 26 U1 0 U2 6 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 1995 VL 59 IS 4 BP 691 EP 696 DI 10.2307/3801945 PG 6 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RY589 UT WOS:A1995RY58900008 ER PT J AU NICHOLS, JD REYNOLDS, RE BLOHM, RJ TROST, RF HINES, JE BLADEN, JP AF NICHOLS, JD REYNOLDS, RE BLOHM, RJ TROST, RF HINES, JE BLADEN, JP TI GEOGRAPHIC-VARIATION IN BAND REPORTING RATES FOR MALLARDS BASED ON REWARD BANDING SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE ANAS PLATYRHYNCHOS; BAND REPORTING RATE; HARVEST RATE; MALLARD; REWARD BANDS ID SURVIVAL; HYPOTHESES; RECOVERY AB We conducted a reward band study on mallards (Anas platyrhynchos) to estimate and test hypotheses about sources of variation in band reporting rate. We banded 25,398 mallards with standard and $100 reward bands (3 mallards banded with standard bands for every reward-banded mallard) during preseason (Jul-Sep), 1988. We used a series of multinomial models to model the resulting 2,776 band recoveries from 1988 to 1991. Estimates of reporting rate for males shot in 10 harvest areas ranged from 0.29 to 0.46 and averaged 0.38 (SE = 0.020). We found evidence (P < 0.01) of geographic variation in reporting rates, but not of smooth latitudinal or longitudinal gradients. There was evidence (P = 0.07) of lower reporting rates for females than males, especially in prairie Canada and the Central Flyway. Except for young males in the northern Atlantic Flyway, estimated harvest rates were lower than historical estimates, as expected from recent restrictive hunting regulations. Patterns of geographic and age-sex variation in harvest rates were similar to those obtained using historical band-recovery data. C1 US FISH & WILDLIFE SERV,BISMARCK,ND 58501. US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,ARLINGTON,VA 22203. RP NICHOLS, JD (reprint author), NATL BIOL SERV,PATUXENT ENVIRONM SCI CTR,LAUREL,MD 20708, USA. NR 21 TC 40 Z9 41 U1 1 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 1995 VL 59 IS 4 BP 697 EP 708 DI 10.2307/3801946 PG 12 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RY589 UT WOS:A1995RY58900009 ER PT J AU HOHMAN, WL MOORE, JL TWEDT, DJ LOGERWELL, E LOGERWELL, E AF HOHMAN, WL MOORE, JL TWEDT, DJ LOGERWELL, E LOGERWELL, E TI AGE CLASS SEPARATION OF BLUE-WINGED DUCKS SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE AGE; ANAS CLYPEATA; ANAS CYANOPTERA; ANAS DISCORS; BLUE-WINGED TEAL; CINNAMON TEAL; DISCRIMINANT ANALYSIS; MOLT; NORTHERN SHOVELER; NUTRITIONAL STRESS; WATERFOWL ID REPRODUCTIVE-PERFORMANCE; PAIRING CHRONOLOGY; FEMALE; CANVASBACKS; DOMINANCE; GADWALLS; MALLARDS AB Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged < 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for Fl. Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual and flyway differences in remigial measurements and reduced performance of age classification models as evidence of high variability in size of blue-winged ducks' remiges. Variability in remigial size of these and other small-bodied waterfowl may be related to nutrition during molt. C1 NATL BIOL SERV,SO SCI CTR,VICKSBURG,MS 39180. US FISH & WILDLIFE SERV,SACRAMENTO NATL WILDLIFE REFUGE,WILLOWS,CA 95988. UNIV CALIF IRVINE,DEPT ECOL & EVOLUTIONARY BIOL,IRVINE,CA 92717. RP HOHMAN, WL (reprint author), NATL BIOL SERV,SO SCI CTR,700 CAJUNDOME BLVD,LAFAYETTE,LA 70506, USA. OI Twedt, Daniel/0000-0003-1223-5045 NR 37 TC 5 Z9 5 U1 1 U2 4 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 1995 VL 59 IS 4 BP 727 EP 735 DI 10.2307/3801949 PG 9 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RY589 UT WOS:A1995RY58900012 ER PT J AU KRAPU, GL REINECKE, KJ JORDE, DG SIMPSON, SG AF KRAPU, GL REINECKE, KJ JORDE, DG SIMPSON, SG TI SPRING-STAGING ECOLOGY OF MIDCONTINENT GREATER WHITE-FRONTED GEESE SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE ALASKA; ANSER ALBIFRONS; DISEASE; FAT; FOODS; HABITAT; MIGRATION; NEBRASKA; NUTRIENT DYNAMICS; PROTEIN; RAINWATER BASIN AREA; RECRUITMENT; SPRING STAGING; TIME BUDGETS; WHITE-FRONTED GEESE ID LESSER SNOW GEESE; REPRODUCTIVE-PERFORMANCE; BODY-COMPOSITION; DIET; ACCUMULATION; MIGRATION; DYNAMICS; RESERVES; HABITATS; IMPACT AB A major part of the midcontinent greater white-fronted goose (Anser albifrons) population stages for several weeks in spring in the Rainwater Basin Area (RBA) of south-central Nebraska where substantial mortality from disease occurs periodically. Effective management of this population requires better data on use of habitat, vulnerability to disease, and the role of staging areas in migration and reproduction. We studied use of habitat, foods, nutrient dynamics, and effect of changes in agriculture on food availability and habitat needs in spring 1979-80. During daylight, geese were observed primarily in harvested cornfields (76%) and growing winter wheat (23%). Corn grain and winter wheal shoots composed 90 and 9%, respectively, of foods consumed by collected geese (n = 42). Feeding activity did not vary among post-harvest cornfield treatments except that little feeding occurred (P < 0.05) in moldboard-plowed fields (< 1%). Fat content for all geese increased (P less than or equal to 0.01) with Julian date; protein content increased (P = 0.03) only among adult females, and there was no evidence (P > 0.05) of temporal variation in calcium content. Adult geese storing 14.2 g of fat per day deposited approximately 582 g of fat between 22 February and 3 April. Energy requirements for thermal regulation were small compared with requirements for fat synthesis and probably had little effect on nutrient deposition, The 34,000 white-fronted geese present on the Harvard Marsh and Prairie Dog Marsh study areas in March 1980 probably used < 20% of the corn available within a 5-km radius. We believe that midcontinent white-fronted geese arrive on Arctic breeding grounds with larger and less variable fat reserves than prior to modern agricultural development. We attribute this response to increased food availability on staging areas where the net effect of agricultural changes has been an increase in corn availability. Waterfowl managers can increase dispersion of geese and provide favorable foraging conditions by maintaining well-distributed wetland roosting habitat and by working with private landowners to ensure access to grain in the vicinity of wetlands. C1 NATL BIOL SERV,PATUXENT ENVIRONM SCI CTR,VICKSBURG,MS 39180. US FISH & WILDLIFE SERV,OFF SPECIAL STUDIES,ANCHORAGE,AK 99503. RP KRAPU, GL (reprint author), NATL BIOL SERV,NO PRAIRIE SCI CTR,8711 37TH ST SE,JAMESTOWN,ND 58401, USA. NR 48 TC 34 Z9 38 U1 0 U2 15 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 1995 VL 59 IS 4 BP 736 EP 746 DI 10.2307/3801950 PG 11 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RY589 UT WOS:A1995RY58900013 ER PT J AU SCHULZ, JH SHERIFF, SL HE, ZQ BRAUN, CE DROBNEY, RD TOMLINSON, RE DOLTON, DD MONTGOMERY, RA AF SCHULZ, JH SHERIFF, SL HE, ZQ BRAUN, CE DROBNEY, RD TOMLINSON, RE DOLTON, DD MONTGOMERY, RA TI ACCURACY OF TECHNIQUES USED TO ASSIGN MOURNING DOVE AGE AND GENDER SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE AGE; GENDER; MOURNING DOVE; SEX RATIOS; TECHNIQUES; ZENAIDA MACROURA AB Sex ratios of mourning doves (Zenaida macroura) reported in banding studies have differed markedly between states and years suggesting that techniques used to assign gender may be biased. We tested this hypothesis with experienced mourning dove biologists (n = 4) who assigned age, gender, primary molt progression, and certainty of classification, using external characteristics of harvested doves (n = 468) in Missouri during September 1993. The probability of correctly classifying adult mourning doves, verified with gonadal examination, was 0.904-0.985 and 0.957-0.990 for immatures. Assessment of age and gender combined was 0.944-0.990 for adult females and 0.533-0.993 for adult males. Error probabilities of observer ability to correctly assign age and gender was 0.0-0.045 for adult females and 0.007-0.451 for adult males. Among individual mourning doves examined, only 1 adult and 6 immature doves were incorrectly assigned age and gender by all 4 participants. Error in assigning gender to adult doves could have contributed to disparate sex ratios reported in previous mourning dove banding studies. We recommend that standard training procedures be developed and implemented across states and regions in future banding studies of mourning doves. C1 COLORADO DIV WILDLIFE,WILDLIFE RES CTR,FT COLLINS,CO 80526. UNIV MISSOURI,NATL BIOL SERV,MISSOURI COOPERAT FISH & WILDLIFE RES UNIT,COLUMBIA,MO 65211. US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,ALBUQUERQUE,NM 87103. US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,LAUREL,MD 20708. MAX MCGRAW WILDLIFE FDN,DUNDEE,IL 60118. RP SCHULZ, JH (reprint author), MISSOURI DEPT CONSERVAT,FISH & WILDLIFE RES CTR,1110 S COLL AVE,COLUMBIA,MO 65201, USA. NR 24 TC 18 Z9 18 U1 0 U2 1 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD OCT PY 1995 VL 59 IS 4 BP 759 EP 765 DI 10.2307/3801953 PG 7 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RY589 UT WOS:A1995RY58900016 ER PT J AU BARTON, BA ZITZOW, RE AF BARTON, BA ZITZOW, RE TI PHYSIOLOGICAL-RESPONSES OF JUVENILE WALLEYES TO HANDLING STRESS WITH RECOVERY IN SALINE WATER SO PROGRESSIVE FISH-CULTURIST LA English DT Article ID TROUT SALMO-GAIRDNERI; FINGERLING RAINBOW-TROUT; ONCORHYNCHUS-KISUTCH; PLASMA-CORTISOL; COHO SALMON; BROWN TROUT; TRUTTA-L; LARGEMOUTH BASS; CHINOOK SALMON; FRESH-WATER AB Juvenile walleyes (Stizostedion vitreum) were subjected to a 30-s net handling to determine their physiological stress responses and differential recovery in freshwater (FW) and saline water (SW; 0.5% NaCl). Plasma cortisol rose from 11 +/- 4.4 ng/mL (mean +/- SE) to 286 +/- 40 ng/mL within 15 min of handling, and blood lymphocyte-erythrocyte (RBC) ratios decreased from 40 +/- 6.0 per thousand RBCs to 13 +/- 0.7 in 3 h. Plasma cortisol recovered more quickly (e.g., 123 +/- 22 ng/mL in FW versus 44 +/- 7.1 in SW at 3 h) and plasma osmolality was less affected (e.g., 269 +/- 4.5 in FW versus 283 +/- 4.7 milliosmol/kg in SW at 6 h) in fish during recovery in SW compared with those in FW. However, declines in lymphocyte-RBC ratios appeared unmodified by salt use. Confining fish during recovery evoked a second increase in plasma cortisol in both FW and SW, but the increase was less in SW (186 +/- 26 and 118 +/- 11 ng/mL, respectively). Plasma osmolality remained unchanged in fish held in SW, and the increase in the neutrophil-RBC ratio evident in confined fish held in FW was moderated in SW An increase in the thrombocyte-RBC ratio occurred in handled fish during recovery in FW without confinement but not in confined fish. The use of salt in the recovery medium did not attenuate corticosteroid responses of walleyes to handling, but salt may have allowed the fish to recover more quickly and eliminated the osmoregulatory imbalance often associated with acute stress. C1 UNIV N DAKOTA,DEPT BIOL,GRAND FORKS,ND 58202. US FISH & WILDLIFE SERV,VALLEY CITY NATL FISH HATCHERY,VALLEY CITY,ND 58072. NR 44 TC 44 Z9 47 U1 5 U2 16 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0033-0779 J9 PROG FISH CULT JI Progress. Fish-Cult. PD OCT PY 1995 VL 57 IS 4 BP 267 EP 276 DI 10.1577/1548-8640(1995)057<0267:PROJWT>2.3.CO;2 PG 10 WC Fisheries SC Fisheries GA TA654 UT WOS:A1995TA65400002 ER PT J AU WATERSTRAT, PR MARKING, LL AF WATERSTRAT, PR MARKING, LL TI CLINICAL-EVALUATION OF FORMALIN, HYDROGEN-PEROXIDE, AND SODIUM-CHLORIDE FOR THE TREATMENT OF SAPROLEGNIA-PARASITICA ON FALL CHINOOK SALMON EGGS SO PROGRESSIVE FISH-CULTURIST LA English DT Note AB The effectiveness of formalin, hydrogen peroxide, and salt (NaCl) in controlling fungal infections on eggs of fall chinook salmon (Oncorhynchus tshawytscha) was evaluated under hatchery conditions. The clinical trial involved the treatment of eggs exposed to Saprolegnia parasitica with daily 15-min treatments of either 500 ppm or 1,000 ppm formalin, 500 ppm or 1,000 ppm hydrogen peroxide, and 15,000 ppm or 30,000 ppm salt (NaCl) solutions. Formalin and hydrogen peroxide at concentrations of either 500 ppm and 1.000 ppm appeared effective in controlling fungal infections on eggs. Salt solution at a concentration of 15,000 ppm failed to effectively control fungal infections. Although salt solution at a concentration of 30,000 ppm controlled fungal infection, the large quantity of salt required to treat eggs over the 35-d incubation period, coupled with an apparent increase in egg mortality, may render 30,000 ppm salt impractical for current hatchery operations. Both hydrogen peroxide and formalin at concentrations of 500 ppm and 1,000 ppm appear to be effective alternatives to the standard hatchery practice of treating eggs with formalin at a concentration of 1,667 ppm. C1 US FISH & WILDLIFE SERV,ABERNATHY SALMON CULTURE TECHNOL CTR,LONGVIEW,WA 98632. US FISH & WILDLIFE SERV,NATL FISHERIES RES CTR,NATL BIOL SERV,LA CROSSE,WI 54602. NR 13 TC 55 Z9 56 U1 1 U2 13 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0033-0779 J9 PROG FISH CULT JI Progress. Fish-Cult. PD OCT PY 1995 VL 57 IS 4 BP 287 EP 291 DI 10.1577/1548-8640(1995)057<0287:CCEOFH>2.3.CO;2 PG 5 WC Fisheries SC Fisheries GA TA654 UT WOS:A1995TA65400004 ER PT J AU AALTO, KR MCLAUGHLIN, RJ CARVER, GA BARRON, JA SLITER, WV MCDOUGALL, K AF AALTO, KR MCLAUGHLIN, RJ CARVER, GA BARRON, JA SLITER, WV MCDOUGALL, K TI UPLIFTED NEOGENE MARGIN, SOUTHERNMOST CASCADIA-MENDOCINO TRIPLE JUNCTION REGION, CALIFORNIA SO TECTONICS LA English DT Article ID NORTHERN CALIFORNIA; COMPLEX; SUBDUCTION; TECTONICS; ACCRETION; PALEOGENE; LIMESTONE; BASIN AB Along a 10-km length of coast north of the Mendocino triple junction, a Neogene accretionary complex has been uplifted greater than or equal to 2 km and tilted northward in response to the interaction of the southern Juan de Fuca (Gorda) plate with the older North American and Pacific plates. These plate interactions were accompanied by tectonic intercalation of Miocene to Pliocene deposits of the southern Cascadia forearc (Wildcat Group), with penetratively deformed Oligocene to Miocene accretionary prism deposits of the False Cape terrane (new name) and the Cretaceous to Eocene Coastal terrace of the Franciscan Complex. North of Cape Mendocino, more than 2 km of stratigraphic section of the accretionary False Cape terrane crops out at beach level in an east-west trending anticline and recumbent syncline. The folded False Cape rocks are juxtaposed with forearc deposits to the north along the subvertical Russ shear zone. To the south, a second subvertical shear zone truncates the False Cape terrane near the mouth of the Bear River. This North Bear River shear zone interleaves rocks of the False Cape and Coastal terranes with additional Neogene forearc deposits (the Bear River beds). South of the North Bear River shear zone, the Bear River beds crop out for about 5 km in a continuous folded and imbricated section that is again truncated to the south by a third subvertical shear zone. This South Bear River shear zone interleaves rocks of the Coastal terrane, the Bear River beds, and Pliocene to Pleistocene shelf deposits. Folding, tilting, and shear zone development reflect ongoing north-south crustal shortening that has occurred in response to interplate coupling and wedge thickening in the deforming Miocene and younger accretionary complex. The strain recorded in the accreted terranes and in the forearc overlap assemblage reflects a stress regime unlike that in Cascadia fold-and-thrust belt north of the Eel River syncline. Thus the deformation pattern may be unique to the triple junction area. The False Cape terrane is one of only two localities along the Cascadia margin where the Oligocene to Miocene accretionary complex is exposed on land. The other locality is that of the Hoh melange on the southwest Olympic Peninsula. On-land exposure of accretionary rocks in these two areas is a consequence of high uplift rates, focused compression, and triple-junction tectonism. Framework grain composition data for sandstones in the Hoh melange and coeval continental deposits in northernmost California (the Oligocene to Miocene Weaverville Formation) suggest a provenance link, while sandstone of the False Cape terrane, presently situated directly west of the Weaverville Formation, is dissimilar. Given the northward component of Farallon (Juan de Fuca) plate translation with respect to North America for the past 20 m.y., provenance links of Hoh and Weaverville sandstones might reflect a substantial component of northward translation between the Farallon and North American plates that was accommodated within the accretionary prism. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP AALTO, KR (reprint author), HUMBOLDT STATE UNIV,DEPT GEOL,ARCATA,CA 95521, USA. NR 51 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD OCT PY 1995 VL 14 IS 5 BP 1104 EP 1116 DI 10.1029/95TC01695 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ633 UT WOS:A1995RZ63300004 ER PT J AU BOGUE, SW GROMME, S HILLHOUSE, JW AF BOGUE, SW GROMME, S HILLHOUSE, JW TI PALEOMAGNETISM, MAGNETIC-ANISOTROPY, AND MIDCRETACEOUS PALEOLATITUDE OF THE DUKE-ISLAND (ALASKA) ULTRAMAFIC COMPLEX SO TECTONICS LA English DT Article ID COAST PLUTONIC COMPLEX; CENTRAL BRITISH-COLUMBIA; REGIONAL TILT RATHER; CENTRAL SOUTHEASTERN ALASKA; LARGE-SCALE DISPLACEMENT; CANADIAN CORDILLERA; NORTH-AMERICA; TERRANE-I; ROCKS; MARGIN AB We report paleomagnetic results from layered igneous rocks that imply substantial post mid-Cretaceous poleward motion of the Insular superterrane (western Canadian Cordillera and southeast Alaska) relative to North America. The samples studied are from the stratiform zoned ultramafic body at Duke Island, which intruded rocks of the Alexander terrane at the south end of the southeastern Alaska archipelago at about 110 Ma. Thermal and alternating field demagnetization experiments show that the characteristic remanence of the ultramafic rocks has high coercivity and a narrow unblocking temperature range just below the Curie temperature of magnetite. This remanence is likely carried by low-Ti titanomagnetite exsolved within clinopyroxene and perhaps other silicate hosts. The Duke Island intrusion exhibits a well-developed gravitational layering that was deformed during initial cooling (but below 540 degrees C) into folds that plunge moderately to the west-southwest. The characteristic remanence clearly predates this early folding and is therefore primary; the Fisher parameter describing the concentration of the overall mean remanence direction improves from 3 to 32 when the site-mean directions are corrected by restoring the layering to estimated paleo-horizontal. All samples exhibit a magnetic anisotropy that is strong but nonuniform in orientation across the intrusion, and we show that it has no significant or systematic effect on the site-mean directions of remanence. At least some of the anisotropy derives from secondary magnetite formed during partial serpentinization. The mean paleomagnetic inclination (56 degrees +/- 10 degrees) corroborates paleomagnetic results from five coeval silicic plutons of the Canadian Coast Plutonic Complex to the south and southeast and implies 3000 km (+/- 1300 km) of poleward transport relative to the North American craton. Between mid-Cretaceous and middle Eocene time, the Insular superterrane and Coast Plutonic Complex shared a common paleolatitude history, with more poleward transport than coeval inboard terranes. C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 67 TC 27 Z9 27 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD OCT PY 1995 VL 14 IS 5 BP 1133 EP 1152 DI 10.1029/95TC01579 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ633 UT WOS:A1995RZ63300006 ER PT J AU WRUCKE, CT STEVENS, CH WOODEN, JL AF WRUCKE, CT STEVENS, CH WOODEN, JL TI THE BUTTE VALLEY AND LAYTON WELL THRUSTS OF EASTERN CALIFORNIA - DISTRIBUTION AND REGIONAL SIGNIFICANCE SO TECTONICS LA English DT Article ID SOUTHERN-CALIFORNIA; CORDILLERA; TECTONICS AB The Butte Valley and Layton Well Thrusts are major structural features in two adjacent mountain ranges west of southern Death Valley. The Butte Valley Thrust in the southern Panamint Range underlies most of the range and emplaces Proterozoic rocks over strata as young as Jurassic(?) in age. The Layton Well Thrust to the southwest in the Slate Range has been interpreted to have Proterozoic rocks juxtaposed on rocks as young as Jurassic, suggesting that the Butte Valley Thrust and the Layton Well Thrust might be correlative. New information indicates that the allochthonous rocks of the Layton Well Thrust are Mesozoic in age and are not likely part of the same allochthon as that above the Butte Valley Thrust. In addition, the Butte Valley Thrust cuts sharply downward to the north and west across lower plate Paleozoic strata, suggesting that the fault roots beneath the Layton Well Thrust. The Layton Well Thrust probably belongs to the East Sierran thrust system and thus would be in the upper plate of the Butte Valley Thrust. C1 SAN JOSE STATE UNIV,DEPT GEOL,SAN JOSE,CA 95192. RP WRUCKE, CT (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS-901,MENLO PK,CA 94025, USA. NR 28 TC 11 Z9 11 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD OCT PY 1995 VL 14 IS 5 BP 1165 EP 1171 DI 10.1029/95TC01932 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ633 UT WOS:A1995RZ63300008 ER PT J AU SACKS, LA HERMAN, JS KAUFFMAN, SJ AF SACKS, LA HERMAN, JS KAUFFMAN, SJ TI CONTROLS ON HIGH SULFATE CONCENTRATIONS IN THE UPPER FLORIDAN AQUIFER IN SOUTHWEST FLORIDA SO WATER RESOURCES RESEARCH LA English DT Article ID WATER; CEMENTATION; GROUNDWATER; ISOTOPE; SYSTEMS; MODELS; SULFUR AB Chemical profiles of groundwater in the Upper Floridan aquifer in southwest Florida vary between an inland and a coastal site. At the inland site, sulfate concentrations increase with depth, and chloride concentrations remain low. At the coastal site; sulfate concentrations are high and constant, but chloride concentrations increase with depth. The sulfate source at the inland site is gypsum dissolution, whereas at the coastal site, the sulfate source is predominantly gypsum dissolution overprinted by saltwater mixing. Mass transfer modeling in conjunction with isotopic data was used to evaluate hypothetical flow paths within the aquifer. Dedolomitization reactions (gypsum and dolomite dissolution with calcite precipitation) dominate along flow paths where sulfate concentrations increase. The distribution of gypsum in the aquifer Indicates that a deeply circulating flow path controls the chemical evolution of groundwater between the two sites. Fresh groundwater moves into deep zones in the aquifer where gypsum is found. Farther along the flow path in the discharge area, this groundwater moves upward to shallower depths prior to the saltwater mixing zone. Saltwater mixing becomes more pronounced with both proximity to the coast and with increasing depth. These results underscore the importance of evaluating vertical, as well as lateral, flow paths when quantifying geochemical reactions in a chemically stratified aquifer. C1 UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. RP SACKS, LA (reprint author), US GEOL SURVEY,4710 EISENHOWER BLVD,SUITE B-5,TAMPA,FL 33634, USA. NR 45 TC 31 Z9 31 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD OCT PY 1995 VL 31 IS 10 BP 2541 EP 2551 DI 10.1029/95WR02105 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RX715 UT WOS:A1995RX71500016 ER PT J AU MCMAHON, PB TINDALL, JA COLLINS, JA LULL, KJ NUTTLE, JR AF MCMAHON, PB TINDALL, JA COLLINS, JA LULL, KJ NUTTLE, JR TI HYDROLOGIC AND GEOCHEMICAL EFFECTS ON OXYGEN-UPTAKE IN BOTTOM SEDIMENTS OF AN EFFLUENT-DOMINATED RIVER SO WATER RESOURCES RESEARCH LA English DT Article ID SURFACE-WATER; NITRIFICATION; GROUNDWATER; RATES AB More than 95% of the water in the South Platte River downstream from the largest wastewater treatment plant serving the metropolitan Denver, Colorado, area consists of treated effluent during some periods of low flow. Fluctuations in effluent-discharge rates caused daily changes in river stage that promoted exchange of water between the river and bottom sediments. Groundwater discharge measurements indicated fluxes of water across the sediment-water interface as high as 18 m(3) s(-1) km(-1). Laboratory experiments indicated that downward movement of surface water through bottom sediments at velocities comparable to those measured in the field (median rate approximate to 0.005 cm s(-1)) substantially increased dissolved oxygen uptake rates in bottom sediments (maximum rate 212 +/- 10 mu mol O-2 L(-1) h(-1)) compared with rates obtained when no vertical advective flux was generated (maximum rate 25 +/- 8.8 mu mol O-2 L(-1) h(-1)). Additions of dissolved ammonium to surface waters generally increased dissolved oxygen uptake rates relative to rates measured in experiments without ammonium. However, the magnitude of the advective flux through bottom sediments had a greater effect on dissolved oxygen uptake rates than did the availability of ammonium. Results from this study indicated that efforts to improve dissolved oxygen dynamics in effluent-dominated rivers might include stabilizing daily fluctuations in river stage. C1 METRO WASTEWATER RECLAMAT DIST,DENVER,CO 80229. RP MCMAHON, PB (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 415,DENVER,CO 80225, USA. NR 14 TC 26 Z9 27 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD OCT PY 1995 VL 31 IS 10 BP 2561 EP 2569 DI 10.1029/95WR02106 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RX715 UT WOS:A1995RX71500018 ER PT J AU WAGNER, BJ AF WAGNER, BJ TI SAMPLING DESIGN METHODS FOR GROUNDWATER MODELING UNDER UNCERTAINTY SO WATER RESOURCES RESEARCH LA English DT Article ID WASTE MANAGEMENT SITES; NETWORK DESIGN; PARAMETER-IDENTIFICATION; AQUIFER REMEDIATION; ENGINEERING DESIGN; REGULATORY POLICY; SOLUTE TRANSPORT; INVERSE PROBLEM; TRACER TEST; CONTAMINATION AB A sampling network design model is presented that evaluates the trade-off between the varying costs of different types of data and the contribution of those data to improving model reliability. The methodology couples parameter-estimate and model-prediction uncertainty analyses with optimization to identify the mix of hydrogeologic information (e.g., head, concentration, and/or hydraulic conductivity measurement locations) that will minimize model prediction uncertainty for a given data collection budget. Two alternative optimization algorithms are presented and compared: a branch-and-bound algorithm and a genetic algorithm. A series of synthetic examples are presented to demonstrate the adaptability of the methodology to different sampling scenarios. The examples reveal two important properties of this network design problem. First, model-parameter and model-prediction uncertainty analyses are important components of the network design methodology because they provide a natural framework for evaluating the cost/information trade-off for different types of data and different sampling network designs. Second, the genetic algorithm can identify near-optimal solutions for a small fraction of the computational effort needed to determine the globally optimal solutions of the branch-and-bound algorithm. RP WAGNER, BJ (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 421,MENLO PK,CA 94025, USA. NR 37 TC 69 Z9 75 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD OCT PY 1995 VL 31 IS 10 BP 2581 EP 2591 DI 10.1029/95WR02107 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RX715 UT WOS:A1995RX71500020 ER PT J AU CARR, MH BELTON, MJS BENDER, K BRENEMAN, H GREELEY, R HEAD, JW KLAASEN, KP MCEWEN, AS MOORE, JM MURCHIE, S PAPPALARDO, RT PLUTCHAK, J SULLIVAN, R THORNHILL, G VEVERKA, J AF CARR, MH BELTON, MJS BENDER, K BRENEMAN, H GREELEY, R HEAD, JW KLAASEN, KP MCEWEN, AS MOORE, JM MURCHIE, S PAPPALARDO, RT PLUTCHAK, J SULLIVAN, R THORNHILL, G VEVERKA, J TI THE GALILEO IMAGING TEAM PLAN FOR OBSERVING THE SATELLITES OF JUPITER SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article; Proceedings Paper CT Icy Galilean Satellites Conference CY FEB, 1994 CL SAN JUAN CAPISTRANO INST, SAN JUAN CAPISTRANO, CA SP Galileo Project Off, San Juan Capistrano Inst HO SAN JUAN CAPISTRANO INST ID INTERNAL STRUCTURE; GROOVED TERRAIN; DOME CRATERS; ICE SHELL; GANYMEDE; EUROPA; CALLISTO; SURFACE; SYSTEM; EVOLUTION AB The Galileo spacecraft carries a 1500-nm focal length camera with a 800 X 800 CCD detector that will provide images with a spatial resolution of 10 mu rad/pixel. The spacecraft will fly by Io at the time of Jupiter Orbit Insertion (JOI) and, subsequently, while in Jupiter's orbit, will have a total of 10 close passes by Europa, Ganymede, and Callisto. These dose passes, together with more distant encounters, will be used by the imaging experiment primarily to obtain high-resolution coverage of selected targets, to fill gaps left in the Voyager coverage, to extend global color coverage of each satellite, and to follow changes in the volcanic activity of Io. The roughly 390 Mbit allocated for imaging during the tour will be distributed among several hundred frames compressed by factors that range from 1 to possibly as high as 50. After obtaining high-resolution samples during the initial Io encounter at JOI, roughly 10% of imaging resources are devoted to near-terminator mapping of Io's topography at 2- to 10-km resolution, monitoring color and albedo changes of the Ionian surface, and monitoring plume activity. Observations of Europa range in resolution from several kilometers per pixel to 10 m/pixel. The objectives of Europa are (1) to determine the nature, origin, and age of the tectonic features, (2) to determine the nature, rates, and sequence of resurfacing events, (3) to assess the satellite's cratering history, and (4) to map variations in spectral and photometric properties. Europa was poorly imaged by Voyager, so the plan includes a mix of high- and low-resolution sequences to provide context. The imaging objectives at Ganymede are (1) to characterize any volcanism, (2) to determine the nature and timing of any tectonic activity, (3) to determine the history of formation and degradation of impact craters, and (4) to determine the nature of the surface materials. Because Ganymede was well imaged by Voyager, most of the resources at Ganymede are devoted to high-resolution observations. The Callisto observations will be directed mostly toward (1) filling Voyager gaps, (2) acquiring high-resolution samples of typical cratered terrain and components of the Valhalla and Asgaard basins, (3) acquiring global color, and (4) determining the photometric properties of the surface. A small number of frames will be used to better characterize the small inner satellites of Jupiter, Thebe, Amalthea, Metis, and Adrastea. C1 NATL OPT ASTRON OBSERV,TUCSON,AZ. ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287. JET PROP LAB,PASADENA,CA. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. US GEOL SURVEY,FLAGSTAFF,AZ 86001. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. APPL PHYS LAB,BALTIMORE,MD. CORNELL UNIV,ITHACA,NY. RP CARR, MH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 70 TC 24 Z9 24 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 25 PY 1995 VL 100 IS E9 BP 18935 EP 18955 DI 10.1029/95JE00971 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RW743 UT WOS:A1995RW74300002 ER PT J AU SMYTHE, WD LOPESGAUTIER, R OCAMPO, A HUI, J SEGURA, M SODERBLOM, LA MATSON, DL KIEFFER, HH MCCORD, TB FANALE, FP CALVIN, WM SUNSHINE, J BARBINIS, E CARLSON, RW WEISSMAN, PR AF SMYTHE, WD LOPESGAUTIER, R OCAMPO, A HUI, J SEGURA, M SODERBLOM, LA MATSON, DL KIEFFER, HH MCCORD, TB FANALE, FP CALVIN, WM SUNSHINE, J BARBINIS, E CARLSON, RW WEISSMAN, PR TI GALILEAN SATELLITE OBSERVATION PLANS FOR THE NEAR-INFRARED MAPPING SPECTROMETER EXPERIMENT ON THE GALILEO SPACECRAFT SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article; Proceedings Paper CT Icy Galilean Satellites Conference CY FEB, 1994 CL SAN JUAN CAPISTRANO INST, SAN JUAN CAPISTRANO, CA SP Galileo Project Off, San Juan Capistrano Inst HO SAN JUAN CAPISTRANO INST ID SULFUR FLOWS; LONGITUDINAL DISTRIBUTION; IOS SURFACE; REFLECTANCE; VOLCANISM; CALLISTO; GANYMEDE; SPECTRA; SO2; VOYAGER-1 AB On December 7, 1995, the Galileo spacecraft will begin observations of the Jovian system with orbit insertion and a satellite tour of 10 orbits. The Galilean satellites will be observed with four remote sensing instruments spanning the ultraviolet, visible, near infrared, and thermal infrared regions of the spectrum. The Galileo near-infrared mapping spectrometer will observe the satellites in the wavelength range 0.7-5.2 mu m, a region particularly well suited for analyzing volatile components. Planned observations include mapping most available longitudes at about 100-km resolution per pixel at full wavelength resolution, together with observing limited regions at high spatial resolution. The opportunity to affect the choice and design of observations for the Galileo tour ex-tends until June 1996. C1 US GEOL SURVEY,ASTROGEOL STUDIES BRANCH,FLAGSTAFF,AZ 86001. UNIV HAWAII,DIV PLANETARY GEOSCI,HONOLULU,HI 96822. SETS TECHNOL INC,MILILANI,HI 96789. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. RP SMYTHE, WD (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Lopes, Rosaly/D-1608-2016 OI Lopes, Rosaly/0000-0002-7928-3167 NR 53 TC 20 Z9 20 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 25 PY 1995 VL 100 IS E9 BP 18957 EP 18972 DI 10.1029/95JE01766 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RW743 UT WOS:A1995RW74300003 ER PT J AU CALVIN, WM CLARK, RN BROWN, RH SPENCER, JR AF CALVIN, WM CLARK, RN BROWN, RH SPENCER, JR TI SPECTRA OF THE ICY GALILEAN SATELLITES FROM 0.2 TO 5 MU-M - A COMPILATION, NEW OBSERVATIONS, AND A RECENT SUMMARY SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article; Proceedings Paper CT Icy Galilean Satellites Conference CY FEB, 1994 CL SAN JUAN CAPISTRANO INST, SAN JUAN CAPISTRANO, CA SP Galileo Project Off, San Juan Capistrano Inst HO SAN JUAN CAPISTRANO INST ID MAGNETOSPHERIC ION-BOMBARDMENT; INFRARED-SPECTRA; REFLECTANCE SPECTROSCOPY; OPTICAL-CONSTANTS; CALLISTO; EUROPA; SPECTROPHOTOMETRY; MICROMETERS; ULTRAVIOLET; AMMONIA AB From a variety of sources in the literature and from recent, unpublished, high-spectral-resolution data, we can now piece together spectra of both leading and trailing hemispheres for all three icy Galilean satellites from 0.24 to 4 or, in some cases, to 5 mu m. The presentation of composite spectra for both hemispheres of all three satellites lends itself to a brief summary of recent results and observations, discussion of the variation in surface composition and surface processing among the three satellites, evolution of our understanding since the comprehensive reviews of the early to mid-1980's, and suggestions for future observations. The data compilation will assist those planning telescopic observations or spectral modeling studies in support of the Galileo mission to Jupiter, those making observations of other icy solar system bodies, or those designing observation plans for the Cassini mission to Saturn. C1 CALTECH,JET PROP LAB,MS 183-501,PASADENA,CA 91109. US GEOL SURVEY,DENVER FED CTR,MS 964,DENVER,CO 80225. LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP CALVIN, WM (reprint author), US GEOL SURVEY,ASTROGEOL BRANCH,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 47 TC 83 Z9 83 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 25 PY 1995 VL 100 IS E9 BP 19041 EP 19048 DI 10.1029/94JE03349 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RW743 UT WOS:A1995RW74300008 ER PT J AU SPENCER, JR CALVIN, WM PERSON, MJ AF SPENCER, JR CALVIN, WM PERSON, MJ TI CHARGE-COUPLED-DEVICE SPECTRA OF THE GALILEAN SATELLITES - MOLECULAR-OXYGEN ON GANYMEDE SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article; Proceedings Paper CT Icy Galilean Satellites Conference CY FEB, 1994 CL SAN JUAN CAPISTRANO INST, SAN JUAN CAPISTRANO, CA SP Galileo Project Off, San Juan Capistrano Inst HO SAN JUAN CAPISTRANO INST ID REFLECTANCE; IO; SURFACE; MICROMETERS; ASTEROIDS; SULFUR AB We have obtained 3200-7800 Angstrom CCD spectra of the Galilean satellites at a variety of orbital longitudes, with spectral resolution between 3 and 18 Angstrom and signal-to-oise ratios of up to 2000 at 6000 Angstrom. Despite the higher resolution and signal-to-noise ratio than previous published spectra, no new features are seen on Io, Europa, and Callisto. However, Ganymede shows an unusual and previously unreported shallow absorption feature at 5773 Angstrom, which is much stronger on the trailing side, and a weaker band at 6275 Angstrom. The features are apparently due to diatomic oxygen, and require simultaneous electronic transitions in two adjacent molecules: they are the strongest visible-wavelength absorption bands in solid or liquid oxygen. Because condensed pure oxygen is not stable at Ganymede surface temperatures and pressures, the oxygen must be trapped in other surface materials, perhaps in water ice, with the constraint that O-2 molecules must be close enough together for simultaneous electronic transitions. Magnetospheric bombardment of water ice is a plausible production mechanism for the O-2. Continuum shapes on all four satellites are more clearly seen than in previous spectra. The shape of the continuum is very similar on Ganymede and Callisto but is strikingly different on Europa, indicating a different origin for the nonice component on Europa. The shape of the Europa continuum suggests that allotropes or compounds of sulfur may be the dominant spectrally active materials in the visible spectrum. No convincing changes since 1978 are visible in Io's spectrum, despite the high resurfacing rates, suggesting that volcanic resurfacing tends to overpaint areas with more material of the same composition. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. RP SPENCER, JR (reprint author), LOWELL OBSERV,1400 W MARS HILL RD,FLAGSTAFF,AZ 86001, USA. NR 32 TC 119 Z9 119 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 25 PY 1995 VL 100 IS E9 BP 19049 EP 19056 DI 10.1029/95JE01503 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RW743 UT WOS:A1995RW74300009 ER PT J AU HELZ, RT BANKS, NG HELIKER, C NEAL, CA WOLFE, EW AF HELZ, RT BANKS, NG HELIKER, C NEAL, CA WOLFE, EW TI COMPARATIVE GEOTHERMOMETRY OF RECENT HAWAIIAN ERUPTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BASALTIC MAGMA AB In this paper we compare lava temperatures measured using Cr-Al thermocouples or infrared spectrometry with estimated quenching temperatures based on the glass geothermometry calibration of Helz and Thornber (1987). Comparative data are available for the April 1982 and September 1982 summit eruptions, the Pu'u 'O'o east rift eruption (1983-1986), all three eruptions at Kilauea, and the 1984 Mauna Loa eruption. The results show that quenching temperatures, based on the MgO contents of Kilauean glasses (T-MgO), lie within +/- 10 degrees C of field measurements using the infrared spectrometer for 85% of the samples. Where a Cr-Al thermocouple was used, 90% of the field measurements lie within +1 degrees to -11 degrees C of T-MgO for samples with T-field > 1130 degrees C. Samples where T-field < 1130 degrees C show larger divergence. The uncertainty in T-MgO by itself is +/- 10 degrees C, so the level of agreement between held measurements and T-MgO is very good for Kilauean lavas. Systematic comparison of field measurements df temperature with glass geothermometry for the 1984 Mauna Loa eruption suggests that, although the field and glass temperatures lie within +/- 10 degrees C of each other, the Kilauean T-MgO calibration is nevertheless not appropriate for Mauna Loa glasses and that actual quenching temperatures for Mauna Loa samples will lie 10 degrees-20 degrees C higher than would be predicted from the Kilauea calibration curve. Consideration of possible effects of variable volatile content suggest that in most cases these are small. Samples erupted early in an eruption may reflect preeruptive water contents different enough to affect T-MgO significantly, but later spatter samples and all flow samples appear to have equilibrated at low enough water contents for the calibration to be applicable. We conclude that the MgO-based geothermometer can be applied to glassy Kilauean samples to give temperatures that generally will lie within +/- 10 degrees C of a field measurement. Plots of glass MgO content versus time, if a suitable sample base is available, should give a thorough, quantitative record of the thermal history of any Kilauean eruption. C1 US GEOL SURVEY, CASCADES VOLCANO OBSERV, VANCOUVER, WA 98661 USA. US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HILO, HI 96718 USA. US GEOL SURVEY, ALASKAN VOLCANO OBSERV, ANCHORAGE, AK 99508 USA. RP HELZ, RT (reprint author), US GEOL SURVEY, NATL CTR, MS959, RESTON, VA 22092 USA. NR 56 TC 20 Z9 20 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1995 VL 100 IS B9 BP 17637 EP 17657 DI 10.1029/95JB01309 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RU400 UT WOS:A1995RU40000005 ER PT J AU RYBERG, T FUCHS, K EGORKIN, AV SOLODILOV, L AF RYBERG, T FUCHS, K EGORKIN, AV SOLODILOV, L TI OBSERVATION OF HIGH-FREQUENCY TELESEISMIC P-N ON THE LONG-RANGE QUARTZ PROFILE ACROSS NORTHERN EURASIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SN PHASES; LITHOSPHERE; MANTLE; WAVE; PROPAGATION; SCATTERING; ATTENUATION; PACIFIC; MODEL AB Short-period, three-component recordings of the seismic wave field of Peaceful Nuclear Explosions (PNEs) on long-range profiles are used to determine the finestructure of the mantle lithosphere. By analyzing the frequency content of the recorded phases and applying different band-pass filters to the data, it is possible to divide the wave field into two distinctly different constituents: low-frequency body waves traveling along Fermat paths (first arrivals) and the high-frequency teleseismic (or long-range) P-n phase traveling with a group velocity of 8.1 km/s and accompanied by a long, incoherent coda. This high-frequency teleseismic P-n phase is observable from about 750 km, where it separates from the faster first arrival, to the maximum recording distance of 3145 km, It is recorded from shots at different locations and appears to be almost unaffected by the major tectonic feature along the profile, the Urals. The frequency spectrum of this P-n phase contains more high-frequency energy (up to 12 Hz) than first arrivals that penetrate deeper into the upper mantle, The teleseismic high-frequency P-n arrival has a remarkable coda, which is incoherent between closely spaced stations, The coda duration is dependent on the component of motion, being shortest on the vertical and longest on the transverse component. We propose a velocity model that is characterized by a zone extending from the crust-mantle boundary to a depth of about 100 km, This zone has randomly distributed, spatially anisotropic velocity fluctuations, We propose that these velocity heterogeneities are ''stretched'' in the horizontal direction, This zone forms a scattering waveguide that confines the high-frequency teleseismic P-n. There are indications that below this P-n waveguide, either the scale of the velocity fluctuations or the Q factor changes. This is expressed in a separation of the teleseismic P-n phase from the phase diving deeper into the mantle lithosphere. C1 GEON, CTR REG GEOPHYS & GEOECOL RES, MOSCOW 119034, RUSSIA. UNIV KARLSRUHE, INST GEOPHYS, D-76187 KARLSRUHE, GERMANY. RP US GEOL SURVEY, MS977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. RI Ryberg, Trond/H-4329-2013 OI Ryberg, Trond/0000-0001-7129-5596 NR 26 TC 55 Z9 57 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1995 VL 100 IS B9 BP 18151 EP 18163 DI 10.1029/95JB01691 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RU400 UT WOS:A1995RU40000041 ER PT J AU CHOY, GL BOATWRIGHT, JL AF CHOY, GL BOATWRIGHT, JL TI GLOBAL PATTERNS OF RADIATED SEISMIC ENERGY AND APPARENT STRESS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MACQUARIE RIDGE EARTHQUAKE; SOURCE PARAMETERS; RUPTURE PROCESS; WAVEFORM DATA; MARCH 3; CHILEAN EARTHQUAKE; GDSN DATA; INVERSION; DROP; ATTENUATION AB Radiated energies from shallow earthquakes with magnitudes greater than or equal to 5.8 that occurred between 1986 and 1991 are used to examine global patterns of energy release and apparent stress. In contrast to traditional methods which have relied upon empirical formulas, these energies are computed through direct spectral analysis of broadband seismic waveforms. Velocity-squared spectra of body waves are integrated after they have been corrected for effects arising from depth phases, frequency-dependent attenuation, and focal mechanism. The least squares regression fit of energy E(S) to surface wave magnitude M(S) for a global set of 397 earthquakes yields log E(S) = 4.4 + 1.5M(S), which implies that the Gutenberg-Richter relationship overestimates the energies of earthquakes. The least squares fit between E(S) and seismic moment M(o) is given by the relationship E(S) = 1.6 X 10(-5)M(o), which yields 0.47 MPa as the average global value of apparent stress. However, the regression lines of both E(S)-M(S) and E(S)-M(o) yield poor empirical predictors for the actual energy radiated by any given earthquake; the scatter of data is more than an order of magnitude about each of the regression lines. On the other hand, global variations between E(S) and M(o), while large, are not random. When subsets of E(S)-M(o) are plotted as a function of seismic region and faulting type, the scatter in data is substantially reduced. The E(S)-M(o) fits for many seismic regions and tectonic environments are very distinctive, and a characteristic apparent stress tau(c) can be derived. The lowest apparent stresses (<1.5 MPa) are associated with thrust earthquakes at subduction zones. The highest apparent stresses (>3.0 MPa) are associated with strike-slip earthquakes that occur at oceanic ridge-ridge transforms and in intraplate environments seaward of island arcs. Intermediate values of apparent stress (1.5 < tau(a) < 3.0 MPa) are associated with strike-slip earthquakes at incipient or transitional plate boundaries. In general the dominant mode of failure for a tectonic environment is associated with the faulting type that has the lowest apparent stress. An energy magnitude M(E) can complement moment magnitude M(W) in describing the size of an earthquake. M(E), being derived from velocity power spectra, is a measure of seismic potential for damage. M(W), being derived from the low-frequency asymptote of displacement spectra, is more physically related to the final static displacement of an earthquake. When earthquake size is ranked by moment, a list of the largest events is dominated by earthquakes with thrust mechanisms. When earthquake size is ranked by energy, the list of the largest events is dominated by strike-slip earthquakes. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP CHOY, GL (reprint author), US GEOL SURVEY, NATL EARTHQUAKE INFORMAT CTR, DENVER FED CTR, BOX 25046, DENVER, CO 80225 USA. NR 41 TC 168 Z9 205 U1 2 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1995 VL 100 IS B9 BP 18205 EP 18228 DI 10.1029/95JB01969 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RU400 UT WOS:A1995RU40000045 ER PT J AU WU, TC SHEN, AH WEATHERS, RS BASSETT, WA CHOU, IM AF WU, TC SHEN, AH WEATHERS, RS BASSETT, WA CHOU, IM TI ANISOTROPIC THERMAL-EXPANSION OF CALCITE AT HIGH-PRESSURES - AN IN-SITU X-RAY-DIFFRACTION STUDY IN A HYDROTHERMAL DIAMOND-ANVIL CELL SO AMERICAN MINERALOGIST LA English DT Article ID TRANSITION AB Lattice parameters of calcite were measured at simultaneous high pressures and temperatures up to 10 kbar and 500 degrees C. Samples of Solnhofen limestone and distilled, deionized water were loaded in a hydrothermal diamond-anvil cell. In situ energy-dispersive X-ray diffraction was used to determine lattice parameters along live H2O isochores with densities of 1.040, 0.964, 0.760, 0.670, and 0.595 g/cm(3) from 30 to 500 degrees C; these densities correspond to the ice-melting temperature of -7.7 degrees C and the liquid-vapor homogenization temperatures 92.4, 274.5, 318.9, and 344.6 degrees C, respectively. In addition, data along the P axis were collected by hydrostatic compression at room temperature and along the T axis by heating at atmospheric pressure. Our results show that anisotropic thermal expansion of calcite continues up to 10 kbar, therefore making it a good double internal X-ray standard. Both a and c lattice parameters are fitted to second-order polynomials of pressure, temperature, and a cross term. C1 US GEOL SURVEY,RESTON,VA 22092. RP WU, TC (reprint author), CORNELL UNIV,DEPT GEOL SCI,MINERAL PHYS LAB,SNEE HALL,ITHACA,NY 14853, USA. RI Shen, Andy/M-5001-2013 OI Shen, Andy/0000-0003-2929-683X NR 17 TC 11 Z9 11 U1 1 U2 4 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1995 VL 80 IS 9-10 BP 941 EP 946 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RY403 UT WOS:A1995RY40300010 ER PT J AU Welch, AH Szabo, Z Parkhurst, DL VanMetre, PC Mullin, AH AF Welch, AH Szabo, Z Parkhurst, DL VanMetre, PC Mullin, AH TI Gross-beta activity in ground water: Natural sources and artifacts of sampling and laboratory analysis SO APPLIED GEOCHEMISTRY LA English DT Article ID RIVER BASIN; THORIUM AB Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements. Although K-40 and Ra-228 appear to be the primary sources of beta activity in ground water, the sum of K-40 plus Ra-228 appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities >10 pCi/L, where these 2 radionuclides account for less than one-half the measured gross-beta activity. One exception is ground water from the Coastal Plain of New Jersey, where K-40 plus Ra generally contribute most of the gross-beta activity. In contrast, K-40 and Ra-228 generally contribute most of beta activity in ground water with gross-beta activities < 1 pCi/L. The gross-beta technique does not measure all beta activity in ground water. Although H-3 contributes beta activity to some ground water, it is driven from the sample before counting and therefore is not detected by gross-beta measurements. Beta-emitting radionuclides with half-lives shorter than a few days can decay to low values between sampling and counting. Although little is known about concentrations of most short-lived beta-emitting radionuclides in environmental ground water (water unaffected by direct releases from nuclear facilities and weapons tests), their activities are expected to be low. Ingrowth of beta-emitting radionuclides during sample holding times can contribute to gross-beta activity, particularly in ground water with gross-beta activities > 10 pCi/L. Ingrowth of beta-emitting progeny of U-238, specifically (234)pa and Th-234, contributes much of the measured gross-beta activity in ground water from 4 of the 5 areas studied. Consequently, gross-beta activity measurements commonly overestimate the abundance of beta-emitting radionuclides actually present in ground water. Differing sample holding times before analysis lead to differing amounts of ingrowth of the two progeny. Therefore, holding times can affect observed gross-beta measurements, particularly ground water with U-238 activities that are moderate to high compared with the activity of K-40 plus Ra-238. Uncertainties associated with counting efficiencies for beta particles with different energies further complicate the interpretation of gross-beta measurements. C1 US GEOL SURVEY,W TRENTON,NJ. US GEOL SURVEY,LAKEWOOD,CO 80225. US GEOL SURVEY,AUSTIN,TX. US GEOL SURVEY,ARVADA,CO. RP Welch, AH (reprint author), US GEOL SURVEY,CARSON CITY,NV, USA. OI Van Metre, Peter/0000-0001-7564-9814 NR 31 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD SEP PY 1995 VL 10 IS 5 BP 491 EP 503 DI 10.1016/0883-2927(95)00020-8 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP127 UT WOS:A1995TP12700001 ER PT J AU Revesz, K Coplen, TB Baedecker, MJ Glynn, PD Hult, M AF Revesz, K Coplen, TB Baedecker, MJ Glynn, PD Hult, M TI Methane production and consumption monitored by stable H and C isotope ratios at a crude oil spill site, Bemidji, Minnesota SO APPLIED GEOCHEMISTRY LA English DT Article ID BACTERIAL METHANE; UNSATURATED ZONE; GRAVEL AQUIFER; CARBON-DIOXIDE; NATURAL GASES; SHALLOW SAND; HYDROGEN; ACETATE; MARINE; GROUNDWATER AB Stable isotopic ratios of C and H in dissolved CH4 and C in dissolved inorganic C in the ground water of a crude-oil spill near Bemidji, Minnesota, support the concept of CH4 production by acetate fermentation with a contemporaneous increase in HCO3- concentration. Methane concentrations in the saturated zone decrease from 20.6 mg L(-1) to less than 0.001 mg L(-1) along the investigated flow path. Dissolved N-2 and Ar concentrations in the ground water below the oil plume are 25 times lower than background; this suggests that gas exsolution is removing dissolved CH4 (along with other dissolved gases) from the ground water. Oxidation of dissolved CH4 along the flow path seems to be minimal because no measurable change in isotopic composition of CH4 occurs with distance from the oil body. However, CH4 is partly oxidized to CO2 as it diffuses upward from the ground water through a 5- to 7-m thick unsaturated zone; the delta(13)C of the remaining CH4 increases, the delta(13)C of the CO2 decreases, and the partial pressure of CO2 increases. Calculations of C fluxes in the saturated and unsaturated zones originating from the degradation of the oil plume lead to a minimum estimated life expectancy of 110 years. This is a minimum estimate because the degradation of the oil body should slow down with time as its more volatile and reactive components are leached out and preferentially oxidized. The calculated life expectancy is an order of magnitude estimate because of the uncertainty in the average linear ground-water velocities and because of the factor of 2 uncertainty in the calculation of the effective CO2 diffusion coefficient. C1 MACALESTER COLL,DEPT GEOL,ST PAUL,MN 55105. RP Revesz, K (reprint author), US GEOL SURVEY,431 NATL CTR,RESTON,VA 22092, USA. NR 48 TC 61 Z9 61 U1 3 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD SEP PY 1995 VL 10 IS 5 BP 505 EP 516 DI 10.1016/0883-2927(95)00021-6 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP127 UT WOS:A1995TP12700002 ER PT J AU LINK, WA SAUER, JR AF LINK, WA SAUER, JR TI ESTIMATION AND CONFIDENCE-INTERVALS FOR EMPIRICAL MIXING DISTRIBUTIONS SO BIOMETRICS LA English DT Article DE BOOTSTRAP; EMPIRICAL BAYES; MIXING DISTRIBUTION; SUMMARY ANALYSIS ID MAXIMUM LIKELIHOOD; BAYES METHODS; VALUES AB Questions regarding collections of parameter estimates can frequently be expressed in terms of an empirical mixing distribution (EMD). This report discusses empirical Bayes estimation of an EMD, with emphasis on the construction of interval estimates. Estimation of the EMD is accomplished by substitution of estimates of prior parameters in the posterior mean of the EMD. This procedure is examined in a parametric model (the normal-normal mixture) and in a semi-parametric model. In both cases, the empirical Bayes bootstrap of Laird and Louis (1987, Journal of the American Statistical Association 82, 739-757) is used to assess the variability of the estimated EMD arising from the estimation of prior parameters. The proposed methods are applied to a meta-analysis of population trend estimates for groups of birds. RP LINK, WA (reprint author), US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708, USA. NR 13 TC 5 Z9 5 U1 0 U2 1 PU INTERNATIONAL BIOMETRIC SOC PI WASHINGTON PA 808 17TH ST NW SUITE 200, WASHINGTON, DC 20006-3910 SN 0006-341X J9 BIOMETRICS JI Biometrics PD SEP PY 1995 VL 51 IS 3 BP 810 EP 821 DI 10.2307/2532983 PG 12 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA RW742 UT WOS:A1995RW74200002 ER PT J AU SHORT, HL HESTBECK, JB AF SHORT, HL HESTBECK, JB TI NATIONAL BIOTIC RESOURCE INVENTORIES AND GAP ANALYSIS - PROBLEMS OF SCALE AND UNPROVED ASSUMPTIONS LIMIT A NATIONAL PROGRAM SO BIOSCIENCE LA English DT Article ID COMMUNITIES C1 UNIV MASSACHUSETTS,MASSACHUSETTS COOPERAT FISH & WILDLIFE RES UNIT,NATL BIOL SERV,AMHERST,MA 01003. RP SHORT, HL (reprint author), US FISH & WILDLIFE SERV,300 WESTGATE CTR DR,HADLEY,MA 01035, USA. NR 23 TC 22 Z9 25 U1 0 U2 0 PU AMER INST BIOL SCI PI WASHINGTON PA 730 11TH STREET, NW, WASHINGTON, DC 20001-4521 SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD SEP PY 1995 VL 45 IS 8 BP 535 EP 539 DI 10.2307/1312698 PG 5 WC Biology SC Life Sciences & Biomedicine - Other Topics GA RT256 UT WOS:A1995RT25600011 ER PT J AU LYONS, PC MILLAY, MA ZODROW, EL CROSS, AT GILLIS, KS AF LYONS, PC MILLAY, MA ZODROW, EL CROSS, AT GILLIS, KS TI DISCOVERY OF PERMINERALIZED PLANT FOSSILS (COAL BALLS) IN THE BOLSOVIAN (EG, WESTPHALIAN C) (MIDDLE PENNSYLVANIAN, UPPER CARBONIFEROUS), STELLARTON BASIN, NOVA-SCOTIA, CANADA SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE LA English DT Article DE PERMINERALIZED PLANTS; COAL BALLS; CARBONIFEROUS; CANADA ID SWAMP VEGETATION AB Permineralized plant fossils (coal balls) of Bolsovian age (ex Westphalian C) were discovered in the Foord seam of the Stellarton Basin of Nova Scotia. The coal-ball plants were preserved in a siderite-dolomite matrix and formed in a nonmarine intermontane setting. The coal-ball flora is dominated by arborescent lycopods and contains a few ferns, as well as occasional seed ferns, calamiteans, and cordaiteans. The following taxa were identified: Diaphorodendron, Paralycopodites brevifolia, Lepidocarpon lomaxii, Stigmaria, Scolecopteris, Botryopteris tridentata, Medullosa, Heterangium, Astromyelon, and Cordaianthus. This assemblage contains plants typical of Westphalian coal-swamp floras and helps fill a stratigraphic gap in Westphalian coal-ball floras of Euramerica. C1 OHIO UNIV,DEPT ECOL & PLANT BIOL,IRONTON,OH 45638. UNIV COLL CAPE BRETON,SYDNEY,NS B1P 6L2,CANADA. MICHIGAN STATE UNIV,DEPT GEOL SCI,E LANSING,MI 48824. NOVA SCOTIA DEPT NAT RESOURCES,STELLARTON,NS B0K 1S0,CANADA. RP LYONS, PC (reprint author), US GEOL SURVEY,MS 956 NATL CTR,RESTON,VA 22092, USA. NR 38 TC 3 Z9 4 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4026 J9 CAN J BOT JI Can. J. Bot.-Rev. Can. Bot. PD SEP PY 1995 VL 73 IS 9 BP 1407 EP 1416 PG 10 WC Plant Sciences SC Plant Sciences GA RX213 UT WOS:A1995RX21300012 ER PT J AU CARRARA, PE AF CARRARA, PE TI A 12000 YEAR RADIOCARBON DATE OF DEGLACIATION FROM THE CONTINENTAL-DIVIDE OF NORTHWESTERN MONTANA SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article ID GLACIER PEAK TEPHRA; NORTH CASCADE RANGE; WASHINGTON; STRATIGRAPHY; AGE AB During the Pinedale (Late Wisconsinan) glaciation, an outlet glacier from a mountain ice field flowed eastward across the Continental Divide through Marias Pass in northwestern Montana. This outlet glacier was the major source of the Two Medicine glacier, a large piedmont glacier that extended from the mountain front east about 55 km onto the plains. An accelerator mass spectrometry radiocarbon age of 12 194 +/- 145 BP (AA-9530) was obtained from a wood fragment, underlying a Glacier Peak tephra and a Mount Saint Helens set J tephra in a section of lake sediments, near Marias Pass. This radiocarbon age provides a minimum date of deglaciation for the Marias Pass area that is about 800 years older than a previous estimate. Furthermore, the radiocarbon age indicates that the Two Medicine glacier was no longer being supplied by its major source and if it still existed was only as a dying, stagnant ice mass. RP CARRARA, PE (reprint author), US GEOL SURVEY, DENVER FED CTR, MAIL STOP 913, LAKEWOOD, CO 80225 USA. NR 16 TC 9 Z9 9 U1 0 U2 0 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD SEP PY 1995 VL 32 IS 9 BP 1303 EP 1307 AR 10.1139/e95-106 DI 10.1139/e95-106 PG 5 WC Geosciences, Multidisciplinary SC Geology GA TF848 UT WOS:A1995TF84800003 ER PT J AU WOODWARD, DF FARAG, AM BERGMAN, HL DELONAY, AJ LITTLE, EE SMITH, CE BARROWS, FT AF WOODWARD, DF FARAG, AM BERGMAN, HL DELONAY, AJ LITTLE, EE SMITH, CE BARROWS, FT TI METALS-CONTAMINATED BENTHIC INVERTEBRATES IN THE CLARK-FORK RIVER, MONTANA - EFFECTS ON AGE-0 BROWN TROUT AND RAINBOW-TROUT SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SALMO-GAIRDNERI RICHARDSON; AQUATIC INSECTS; HEAVY-METALS; DIETARY; FOOD; TOXICITY; CADMIUM; ZINC; LEAD; FISH AB Benthic organisms in the upper Clark Fork River have recently been implicated as a dietary source of metals that may be a chronic problem for young-of-the-year rainbow trout (Oncorhynchus mykiss). In this present study, early life stage brown trout (Salmo trutta) and rainbow trout were exposed for 88 d to simulated Clark Fork River water and a diet of benthic invertebrates collected from the river. These exposures resulted in reduced growth and elevated levels of metals in the whole body of both species. Concentrations of As, Cd, Cu, and Pb increased in whole brown trout; in rainbow trout, As and Cd increased in whole fish, and As also increased in liver. Brown trout on the metals-contaminated diets exhibited constipation,,out impaction, increased cell membrane damage (lipid peroxidation), decreased digestive enzyme production (zymogen), and a sloughing of intestinal mucosal epithelial cells. Rainbow trout fed the contaminated diets exhibited constipation and reduced feeding activity. We believe that the reduced standing crop of trout in the Clark Fork River results partly from chronic effects of metals contamination in benthic invertebrates that are important as food for young-of-the-year fish. C1 UNIV WYOMING,DEPT ZOOL & PHYSIOL,LARAMIE,WY 82071. NATL BIOL SERV,MIDWEST SCI CTR,COLUMBIA,MO 65201. US FISH & WILDLIFE SERV,BOZEMAN FISH TECHNOL CTR,BOZEMAN,MT 59715. RP WOODWARD, DF (reprint author), NATL BIOL SERV,MIDWEST SCI CTR,JACKSON FIELD STN,POB 1089,JACKSON,WY 83001, USA. NR 35 TC 88 Z9 92 U1 2 U2 18 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1995 VL 52 IS 9 BP 1994 EP 2004 DI 10.1139/f95-791 PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA TH585 UT WOS:A1995TH58500017 ER PT J AU FARAG, AM STANSBURY, MA HOGSTRAND, C MACCONNELL, E BERGMAN, HL AF FARAG, AM STANSBURY, MA HOGSTRAND, C MACCONNELL, E BERGMAN, HL TI THE PHYSIOLOGICAL IMPAIRMENT OF FREE-RANGING BROWN TROUT EXPOSED TO METALS IN THE CLARK-FORK RIVER, MONTANA SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID RAINBOW-TROUT; SALMO-GAIRDNERI; LIPID-PEROXIDATION; GLUTATHIONE-PEROXIDASE; SALVELINUS-FONTINALIS; COPPER; CADMIUM; METALLOTHIONEIN; TOXICITY; LEAD AB Tissue metal accumulation and physiological responses were measured in brown trout (Salmo trutta) collected from two sites on the Clark Fork River, Montana, and two reference sites to determine the health status of the resident fish population. Concentrations of metals in tissues, products of lipid peroxidation, and microscopic Cu inclusions were significantly higher in fish collected from the upper Clark Fork River site than in fish from reference sites. Metallothionein concentrations were higher in the livers of fish from the upper Clark Fork River than in those of fish from reference sites. The health of the fish population in the upper Clark Fork River is probably impaired because of previously reported elevated concentrations of metals including As, Cd, Cu, Pb, and Zn in the surface water and aquatic invertebrates in the upper Clark Fork River. The high concentrations of metals in the surface waters and sediments of the Clark Fork River are typical of rivers in the intermountain western United States where discharges from mining activities have occurred since the late 1800s. Thus, our findings can be used as a guide for researchers throughout the intermountain western United States who may investigate similar field conditions. C1 UNIV WYOMING,DEPT ZOOL & PHYSIOL,LARAMIE,WY 82071. MCMASTER UNIV,DEPT BIOL,HAMILTON,ON L8S 4K1,CANADA. US FISH & WILDLIFE SERV,BOZEMAN FISH TECHNOL CTR,BOZEMAN,MT 59715. RI Hogstrand, Christer/C-9041-2013 NR 51 TC 80 Z9 85 U1 1 U2 18 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1995 VL 52 IS 9 BP 2038 EP 2050 DI 10.1139/f95-795 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA TH585 UT WOS:A1995TH58500021 ER PT J AU LARSON, SJ CAPEL, PD GOOLSBY, DA AF LARSON, SJ CAPEL, PD GOOLSBY, DA TI RELATIONS BETWEEN PESTICIDE USE AND RIVERINE FLUX IN THE MISSISSIPPI RIVER BASIN SO CHEMOSPHERE LA English DT Article AB In an intensive subcontinental study of pesticides in surface waters of the United States, concentrations of 26 high-use pesticides were measured at nine sites in the Mississippi River basin from May 1991 through March 1992. Calculated total fluxes were combined with agricultural-use data to estimate the percentage of applied pesticide reaching the mouths of the Mississippi River and six major tributaries. For most pesticides, the riverine flux was less than 2% of the mass applied agriculturally. The fluxes were only marginally related to runoff-potential ratings based solely on the pesticides' chemical and environmental properties. The insecticide diazinon was detected frequently in rivers draining the three basins with the highest population densities, apparently as a result of urban use. C1 US GEOL SURVEY,DIV WATER RESOURCES,LAKEWOOD,CO 80225. US GEOL SURVEY,DIV WATER RESOURCES,ARVADA,CO 80002. RP LARSON, SJ (reprint author), US GEOL SURVEY,GRAY FRESHWATER BIOL INST,DIV WATER RESOURCES,NAVARRE,MN 55392, USA. OI Sandstrom, Mark/0000-0003-0006-5675 NR 23 TC 86 Z9 88 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD SEP PY 1995 VL 31 IS 5 BP 3305 EP 3321 DI 10.1016/0045-6535(95)00176-9 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA RW143 UT WOS:A1995RW14300011 ER PT J AU DETTINGER, MD GHIL, M KEPPENNE, CL AF DETTINGER, MD GHIL, M KEPPENNE, CL TI INTERANNUAL AND INTERDECADAL VARIABILITY IN UNITED-STATES SURFACE-AIR TEMPERATURES, 1910-87 SO CLIMATIC CHANGE LA English DT Article ID PRINCIPAL COMPONENTS ANALYSES; SINGULAR-SPECTRUM ANALYSIS; NORTHERN-HEMISPHERE; DOMAIN SHAPE; TIME-SERIES; INTRASEASONAL OSCILLATIONS; SOUTHERN OSCILLATION; GLOBAL ATMOSPHERE; CLIMATE CHANGE; FLUCTUATIONS AB Monthly mean surface-air temperatures at 870 sites in the contiguous United States were analyzed for interannual and interdecadal variability over the time interval 1910-87. The temperatures were analyzed spatially by empirical-orthogonal-function analysis and temporally by singular-spectrum analysis (SSA). The dominant modes of spatio-temporal variability are trends and nonperiodic variations with time scales longer than 15 years, decadal-scale oscillations with periods of roughly 7 and 10 years, and interannual oscillations of 2.2 and 3.3 years. Together, these modes contribute about 18% of the slower-than-annual United States temperature variance. Two leading components roughly capture the mean hemispheric temperature trend and represent a long-term warming, largest in the southwest, accompanied by cooling of the domain's southeastern quadrant. The extremes of the 2.2-year interannual oscillation characterize temperature differences between the Northeastern and Southwestern States, whereas the 3.3-year cycle is present mostly in the Western States. The 7- to 10-year oscillations are much less regular and persistent than the interannual oscillations and characterize temperature differences between the western and interior sectors of the United States. These continental- or regional-scale temperature variations may be related to climatic variations with similar periodicities, either global or centered in other regions; such variations include quasi-biennial oscillations over the tropical Pacific or North Atlantic and quasi-triennial oscillations of North Pacific sea-surface temperatures. C1 UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA. CALTECH,JET PROP LAB,NASA,PASADENA,CA 91109. RP DETTINGER, MD (reprint author), US GEOL SURVEY,SAN DIEGO,CA 92123, USA. NR 66 TC 46 Z9 47 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD SEP PY 1995 VL 31 IS 1 BP 35 EP 66 DI 10.1007/BF01092980 PG 32 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TA779 UT WOS:A1995TA77900004 ER PT J AU GAZIS, CA LANPHERE, M TAYLOR, HP GURBANOV, A AF GAZIS, CA LANPHERE, M TAYLOR, HP GURBANOV, A TI AR-40/AR-39 AND O-18/O-16 STUDIES OF THE CHEGEM ASH-FLOW CALDERA AND THE ELDJURTA GRANITE - COOLING OF 2 LATE PLIOCENE IGNEOUS BODIES IN THE GREATER-CAUCASUS MOUNTAINS, RUSSIA SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID METAMORPHIC ROCKS; AGE SPECTRA; TEMPERATURE; DIFFUSION; EXAMPLE; COMPLEX AB Volcanic and intrusive rocks of the Chegem caldera and the nearby Eldjurta (Eldzhurtinskiy) Granite record a late Pliocene episode of silicic magmatism in the north-central Caucasus Mountains. Surface exposures, created by the recent rapid uplift and erosion of the Caucasus Mountains, span a 2 km vertical section of Chegem caldera fill and 1150 m of the Eldjurta Granite; cored mineral-exploration drillholes in the Eldjurta Granite extend the sampling to a depth of 4 km. The unique sampling range available in these two young igneous bodies affords an excellent opportunity to study their denudation and cooling histories, which we examine by means of Ar-40/Ar-39 and O-18/O-16 measurements on an extensive sample suite. Total-fusion biotite and sanidine ages from eight Chegem Tuff samples, both intracaldera and outflow, are analytically indistinguishable with a weighted mean of 2.82 +/- 0.02 Ma. A cross-cutting granodiorite porphyry intrusion has a sanidine total fusion age of 2.84 +/- 0.03 Ma, and whole-rock incremental heating of a post-caldera andesite flow, which caps the caldera fill, yields an age of 2.82 +/- 0.02 Ma, Thus, caldera formation and post-caldera resurgence and volcanism all occurred within a very short time (< 50,000 yr). Biotite total-fusion ages of ten Eldjurta Granite samples, including seven from similar to 500 m intervals in the 4 km deep drillhole, show a systematic linear decrease in age with depth from 1.90 Ma near the roof contact of the granite to 1.56 Ma at a depth of 3700 m. Assuming these ages were set at the same temperature, this age/depth gradient implies an isotherm migration rate of 13 mm/yr between 1.90 and 1.56 Ma. This migration rate is due to a combination of rapid denudation and downward relaxation of isotherms, with cooling rates between 200 and 500 degrees C/Ma during this period. Oxygen isotopic compositions of quartz, K-feldspar, plagioclase and biotite from the drillhole samples below the 800 m depth are fairly uniform and record primary igneous delta(18)O values with little evidence for subsolidus hydrothermal activity. However, in surface outcrop samples and in the shallowest drillhole sample, mineral delta(18)O values have been lowered by up to 3 parts per thousand by interaction with an external (meteoric-hydrothermal?) fluid. The primary mineral delta(18)O values of the Eldjurta Granite are distinctly higher than the corresponding phenocryst delta(18)O values in the Chegem volcanic rocks, indicating that the two bodies evolved as separxate magma batches. C1 CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125. US GEOL SURVEY,MENLO PK,CA 94025. RUSSIAN ACAD SCI,INST ORE DEPOSIT GEOL PETROG MINERAL & GEOCHE,MOSCOW 109017,RUSSIA. NR 36 TC 35 Z9 39 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP PY 1995 VL 134 IS 3-4 BP 377 EP 391 DI 10.1016/0012-821X(95)00141-X PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RY541 UT WOS:A1995RY54100012 ER PT J AU PUCKETT, LJ AF PUCKETT, LJ TI IDENTIFYING THE MAJOR SOURCES OF NUTRIENT WATER-POLLUTION SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CONSTITUENT LOADS; CHESAPEAKE BAY; NITROGEN RP PUCKETT, LJ (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092, USA. NR 20 TC 57 Z9 59 U1 4 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1995 VL 29 IS 9 BP A408 EP A414 DI 10.1021/es00009a001 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA RT053 UT WOS:A1995RT05300014 ER PT J AU COSTON, JA FULLER, CC DAVIS, JA AF COSTON, JA FULLER, CC DAVIS, JA TI PB2+ AND ZN2+ ADSORPTION BY A NATURAL ALUMINUM-BEARING AND IRON-BEARING SURFACE COATING ON AN AQUIFER SAND SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HEAVY-METALS; OXIDE; DISSOLUTION; SEDIMENTS; CALCITE; SOILS; ZINC; OXYHYDROXIDES; ENVIRONMENT; DIAGENESIS AB Pb2+ and Zn2+ adsorption was studied in batch experiments with material collected from a shallow, unconfined aquifer of glacial outwash sand and gravel in Falmouth, Massachusetts, USA. The aquifer solids contain primarily quartz (95% w/w), with minor amounts of alkali feldspars and ferromagnetic minerals. Pb2+ and Zn2+ adsorption experiments with various grain size and mineral fractions of the aquifer solids showed that (1) Zn2+ adsorption was independent of grain size, but Pb2+ was preferentially adsorbed by the <64 mu m size fraction and (2) Pb2+ adsorption decreased after removal of the paramagnetic, Fe-bearing mineral fraction, but Zn2+ adsorption was unaffected. Pb2+ and Zn2+ adsorption on mineral separates from the aquifer material compared with metal adsorption on a purified quartz powder indicated that adsorption of both metal ions was dominated by coatings on the quartz fraction of the sediment. Characterization of the coatings by AES, SEM-EDS, and TOF- SIMS demonstrated that the natural quartz grains were extensively coated with Al- and Fe-bearing minerals of variable composition. Thin sections of quartz grains examined by TEM showed that the coatings contained both polycrystalline regions and single mineral crystals. The coating thickness varied from <10 nm up to 30 mu m. The coatings were mostly resistant to dissolution by an extraction protocol designed to dissolve noncrystalline phases. The effect on metal adsorption of dissolving surface coatings from the sediment by chemical extraction was also measured. A hydroxylamine-HCl extraction designed to dissolve crystalline Fe oxide phases decreased Pb2+ and Zn2+ adsorption relative to untreated sediment extracted Fe/Al approximate to 1), but Pb2+ and Zn2+ adsorption were not appreciably changed after sediment was extracted with dithionite-citrate (extracted Fe/AI approximate to 5). Overall, the results suggest that Pb2+ preferred to form complexes with iron hydroxyl sites, while aluminol sites were more important for Zn2+ adsorption. However, a definitive understanding of adsorption reactions in groundwaters will require detailed studies of the extensive coatings formed at mineral-water interfaces by chemical weathering processes. RP COSTON, JA (reprint author), US GEOL SURVEY, DIV WATER RESOURCES, 345 MIDDLEFIELD RD, MS 465, MENLO PK, CA 94025 USA. NR 70 TC 196 Z9 205 U1 2 U2 35 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1995 VL 59 IS 17 BP 3535 EP 3547 DI 10.1016/0016-7037(95)00231-N PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RV075 UT WOS:A1995RV07500007 ER PT J AU WAYCHUNAS, GA DAVIS, JA FULLER, CC AF WAYCHUNAS, GA DAVIS, JA FULLER, CC TI GEOMETRY OF SORBED ARSENATE ON FERRIHYDRITE AND CRYSTALLINE FEOOH - REEVALUATION OF EXAFS RESULTS AND TOPOLOGICAL FACTORS IN PREDICTING SORBATE GEOMETRY, AND EVIDENCE FOR MONODENTATE COMPLEXES SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Note ID ABSORPTION FINE-STRUCTURE AB Manceau's (1995) reinterpretation of some of our EXAFS results (Waychunas et al., 1993) has been analyzed using both old and newly collected data in an attempt to clarify the nature of proposed monodentate and edge-sharing bidentate arsenate complexes on the ferrihydrite surface. It is shown that EXAFS analysis utilizing data with sufficient k-range does indicate the presence of relatively short As-Fe bonds, suggestive of an edge-sharing complex as indicated by Manceau (1995). However, a variety of data analysis factors and crystal chemical considerations create doubt in this assignment. Most significantly, X-ray scattering data collected on a sample of ferrihydrite with a large density of sorbed arsenate, which should show a substantial fraction of the edge-sharing complex, does not show any such correlation within fitting uncertainty. We also suggest that it is unnecessary to invoke the presence of edge-sharing bidentate arsenate to explain the surface growth poisoning of ferrihydrite with increasing sorbed arsenate, as Manceau (1995) claims. Further, we show that a model based on the topology of close packed oxygen ions offers a clear explanation why monodentate arsenate should appear on some surfaces and not on others, and why differing As-Fe distances might be observed on a single surface with a single type of complex, This model also explains why bidentate sorbed arsenate can occupy positions with consistent ''tilt'' angles. Without such consistency, the sorbed arsenate would be highly positionally disordered, and difficult to detect accurately via EXAFS methods. C1 US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. RP WAYCHUNAS, GA (reprint author), STANFORD UNIV,CTR MAT RES,STANFORD,CA 94305, USA. OI Fuller, Christopher/0000-0002-2354-8074 NR 6 TC 148 Z9 160 U1 3 U2 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1995 VL 59 IS 17 BP 3655 EP 3661 DI 10.1016/0016-7037(95)00276-6 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RV075 UT WOS:A1995RV07500016 ER PT J AU REHEIS, MC GOODMACHER, JC HARDEN, JW MCFADDEN, LD ROCKWELL, TK SHROBA, RR SOWERS, JM TAYLOR, EM AF REHEIS, MC GOODMACHER, JC HARDEN, JW MCFADDEN, LD ROCKWELL, TK SHROBA, RR SOWERS, JM TAYLOR, EM TI QUATERNARY SOILS AND DUST DEPOSITION IN SOUTHERN NEVADA AND CALIFORNIA SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID EASTERN MOJAVE DESERT; PEDOGENIC PROCESSES; CLIMATIC CHANGES; PARENT MATERIAL; VOLCANIC FIELD; GREAT-BASIN; HOLOCENE; CARBONATE; GENESIS; RATES AB Eolian dust constitutes much of the pedogenic material in late Pleistocene and Holocene soils of many arid regions of the world. Comparison of the compositions and influx rates of modern dust with the eolian component of dated soils at 24 sites in southern Nevada and California yields information on (1) the composition and influx rate of dust in late Pleistocene and Holocene soils, (2) paleoclimate and its effects on the genesis of aridic soils, especially with regard to dustfall events, (3) the timing and relative contribution of dust from playa sources versus alluvial sources, and (4) the effects of accumulation of dust in soil horizons. The <2 mm fractions of A and B horizons of soils formed on gravelly alluvial-fan deposits in the study area are similar to modern dust in grain size, content of CaCO3 and salt, major oxides, and clay mineralogy; thus, they are interpreted tb consist largely of dust. The major-oxide compositions of the shallow soil horizons are nearly identical to that of the modern dust, but the compositions of progressively deeper horizons approach that of the parent material. The clay mineralogy of modern dust at a given site is similar to that of the Av horizons of nearby Holocene soils but is commonly different from the mineralogies of deeper soil horizons and of the Av horizons of nearby Pleistocene soils. These results are interpreted to indicate that dust both accumulates and is transformed in Av horizons with time. Changes in soil-accumulation rates provide insights into the interplay of paleoclimate, dust supply, and soil-forming processes. Modern dust-deposition rates are more than large enough to account for middle and late Holocene soil-accumulation rates at nearly all sites. However, the early Holocene soil-accumulation rates in areas near late Pleistocene pluvial lakes are much higher than modern rates and clearly indicate a dust-deflation and -deposition event that caused rapid formation of fine-grained shallow soil horizons on uppermost Pleistocene and lower Holocene deposits. We interpret late Pleistocene soil-accumulation rates to indicate that dust-deposition rates were low during this period but that increased effective moisture during the late Wisconsinan favored translocation of clay and CaCO3 from near the surface to deeper in the soil profile. Pre-late Pleistocene rates are very low in most areas, mainly due to a pedogenic threshold that was crossed when accumulations of silt, clay, and CaCO3 began to inhibit the downward transport of eolian material, but in part due to erosion. C1 SAN DIEGO STATE UNIV,DEPT GEOL SCI,SAN DIEGO,CA 92182. US GEOL SURVEY,MENLO PK,CA 94025. UNIV NEW MEXICO,DEPT GEOL SCI,ALBUQUERQUE,NM 87131. WILLIAM LETTIS & ASSOCIATES,OAKLAND,CA 94607. RP REHEIS, MC (reprint author), US GEOL SURVEY,FED CTR,BOX 250,LAKEWOOD,CO 80225, USA. NR 76 TC 125 Z9 127 U1 4 U2 20 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 1995 VL 107 IS 9 BP 1003 EP 1022 DI 10.1130/0016-7606(1995)107<1003:QSADDI>2.3.CO;2 PG 20 WC Geosciences, Multidisciplinary SC Geology GA RT699 UT WOS:A1995RT69900001 ER PT J AU BLAKELY, RJ WELLS, RE YELIN, TS MADIN, IP BEESON, MH AF BLAKELY, RJ WELLS, RE YELIN, TS MADIN, IP BEESON, MH TI TECTONIC SETTING OF THE PORTLAND-VANCOUVER AREA, OREGON AND WASHINGTON - CONSTRAINTS FROM LOW-ALTITUDE AEROMAGNETIC DATA SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID CASCADE RANGE; SEGMENTATION; ROTATION; ARC AB Seismic activity in the Portland-Vancouver metropolitan area may be associated with various mapped faults that locally offset volcanic basement of Eocene age and younger. This volcanic basement is concealed in most places by young deposits, vegetation, and urban development. The U.S. Geological Survey conducted an aeromagnetic survey in September 1992 to investigate the extent of these mapped faults and possibly to help identify other seismic and volcanic hazards in the area. The survey was flown approximately 240 m above terrain, along flight lines spaced 460 m apart, and over an area about 50 x 50 km. These magnetic data indicate a pronounced northwest-striking magnetic lineation east of the Willamette River in downtown Portland associated with a fault concealed beneath Quaternary sedimentary deposits and previously inferred from shallow well data. The magnetic lineation confirms the existence of the fault and suggests that it has had a prolonged history: (1) Although well data indicate <200 m of vertical offset of underlying volcanic basement, models based on the aeromagnetic data from down-town Portland suggest reverse faulting with up to 1 km of offset deeper in the section. (2) The magnetic lineation associated with this fault extends southeast to the Clackamas River drainage, a distance of 50 km and considerably beyond the mapped extent of the fault. A northwest-striking magnetic anomaly located southwest of the Tualatin Mountains corresponds closely with another mapped fault and with mixed reverse and strike-slip faulting during a seismic swarm (M less than or equal to 3) in 1991. We believe these and other anomalies in the aeromagnetic data reflect the Portland Hills fault zone, believed to be the southwestern boundary of a structural basin now occupied by Portland and Vancouver. The postulated northeastern boundary of the basin, the Frontal fault zone, is also evident, although less well represented in the aeromagnetic data. Aeromagnetic anomalies, geologic mapping, and earthquake focal-plane solutions demonstrate a complex deformational history in the Portland-Vancouver area since middle Miocene time that includes elements of compression, extension, and dextral slip. These complexities reflect Portland-Van couver's unique position within a north-south transition in tectonic styles along the Cascadia margin, from compressional in the north to extensional in the south. C1 UNIV WASHINGTON,US GEOL SURVEY,GEOPHYS PROGRAM AK50,SEATTLE,WA 98195. OREGON DEPT GEOL & MINERAL IND,PORTLAND,OR 97230. PORTLAND STATE UNIV,DEPT GEOL,PORTLAND,OR 97207. RP BLAKELY, RJ (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 35 TC 16 Z9 16 U1 2 U2 10 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 1995 VL 107 IS 9 BP 1051 EP 1062 DI 10.1130/0016-7606(1995)107<1051:TSOTPV>2.3.CO;2 PG 12 WC Geosciences, Multidisciplinary SC Geology GA RT699 UT WOS:A1995RT69900004 ER PT J AU YAMAGUCHI, DK HOBLITT, RP AF YAMAGUCHI, DK HOBLITT, RP TI TREE-RING DATING OF PRE-1980 VOLCANIC FLOWAGE DEPOSITS AT MOUNT ST-HELENS, WASHINGTON SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID PLANT SUCCESSION; ERUPTIONS; MUDFLOW; HISTORY; DEBRIS; LAHARS AB Tree-ring dating (ring-width pattern matching) was used to determine emplacement dates for eight subfossil-tree-bearing, pre-1980 pyroclastic-flow and lahar deposits in stream valleys draining Mount St, Helens, Washington, Limiting dates were also established for nine other pre-1980 flowage deposits from the ages of trees rooted on or near them, or from exhumed trees. The 17 new dates improve understanding of the chronology of events during and after Mount St. Helens's Kalama eruptive period, which extended from A.D. 1479 to the mid-1700s. We assign bracketing dates to the three phases of the Kalama eruptive period: 1479-1510 to the early Kalama, during which Mount St. Helens erupted explosive dacitic tephras, pyroclastic flows, and one or more domes; 1489-1566 to the middle Kalama, during which Mount St. Helens produced andesitic tephras, pyroclastic flows, and lava flows; and 1489-1750 to the late Kalama, during which Mount St. Helens again erupted dacite. Overlap of the brackets reflects the limits of our dating resolution. The revised chronology confirms that little time (perhaps 50 yr) elapsed between the end of Mount St. Helens's Kalama eruptive period and the start of the succeeding Goat Rocks eruptive period (A.D. 1800-1857). Eruptions apparently occurred sporadically during the entire 1479-1857 interval. The record also indicates that a large pyroclastic flow occurred 7-10 yr after the explosive eruptions that began the Kalama eruptive period. The dates further imply that extrusion of the pre-1980 summit dome continued intermittently for approximate to 100 yr and limit the ages of two tephras. These findings demonstrate the usefulness of relict tree-bearing deposits to volcanic history studies. C1 UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. RP YAMAGUCHI, DK (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 61 TC 13 Z9 14 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 1995 VL 107 IS 9 BP 1077 EP 1093 DI 10.1130/0016-7606(1995)107<1077:TRDOPV>2.3.CO;2 PG 17 WC Geosciences, Multidisciplinary SC Geology GA RT699 UT WOS:A1995RT69900006 ER PT J AU WALTON, AW WOJCIK, KM GOLDSTEIN, RH BARKER, CE AF WALTON, AW WOJCIK, KM GOLDSTEIN, RH BARKER, CE TI DIAGENESIS OF UPPER CARBONIFEROUS ROCKS IN THE OUACHITA FORELAND SHELF IN MIDCONTINENT USA - AN OVERVIEW OF WIDESPREAD EFFECTS OF A VARISCAN-EQUIVALENT OROGENY SO GEOLOGISCHE RUNDSCHAU LA English DT Article; Proceedings Paper CT Evolution of Variscan (Hercynian) and Comparable Paleozoic Orogenic Belts Meeting CY FEB 17-19, 1994 CL PRAGUE, CZECH REPUBLIC SP Czech Geol Soc, Geolog Vereinig DE DIAGENESIS; FLUID FLOW; FLUID COMPOSITION; FORELAND; VARISCAN-TYPE OROGEN; OUACHITA MOUNTAINS; LATE CARBONIFEROUS ID LEAD-ZINC DEPOSITS; STRATABOUND ORE-DEPOSITS; NORTH-AMERICA; GROUNDWATER-FLOW; GENESIS; MISSOURI; SHALE; STRATIGRAPHY; BRACHIOPODS; MIGRATION AB Diagenesis of Upper Carboniferous foreland shelf rocks in southeastern Kansas took place at temperatures as high as 100-150 degrees C at a depth of less than 2 km. High temperatures are the result of the long distance (hundreds of kilometers) advection of groundwater related to collisional orogeny in the Ouachita tectonic belt to the south. Orogenic activity in the Ouachita area was broadly Late Carboniferous, equivalent to the Variscan activity of Europe. Mississippi Valley-type Pb-Zn deposits and oil and gas fields in the US midcontinent and elsewhere are commonly attributed to regional groundwater flow resulting from such collisional events. This paper describes the diagenesis and thermal effects in sandstone and limestone of Upper Carboniferous siliciclastic and limestone-shale cyclothems, the purported confining layer of a supposed regional aquifer. Diagenesis took place in early, intermediate, and late stages. Many intermediate and late stage events in the sandstones have equivalents in the limestones, suggesting that the causes were regional. The sandstone paragenesis includes siderite cement (early stage), quartz overgrowths (intermediate stage), dissolution of feldspar and carbonates, followed by minor Fe calcite, pore-filling kaolinite and sub-poikilotopic Ca ankerite (late stage). The limestone paragenesis includes calcite cement (early stage); megaquartz, chalcedeny, and Fe calcite spar (intermediate stage); and dissolution, Ca-Fe dolomite and kaolinite (late stage). The R(m) value of vitrinite shows a regional average of 0.6-0.7%; Rock-Eval T-max suggests a comparable degree of organic maturity. The T-h of aqueous fluid inclusions in late stage Ca-Fe-Mg carbonates ranges from 90 to 160 degrees and T-mice indicates very saline water (> 200 000 ppm NaCl equivalent); delta(18)O suggests that the water is of basinal origin. Local warm spots have higher R(m), T-max, and T-h. The results constrain numerical models of regional fluid migration, which is widely viewed as an artesian flow from recharge areas in the Ouachita belt across the foreland basin onto the foreland shelf area. Such models must account for heating effects that extend at least 500 km from the orogenic front and affect both supposed aquifer beds and the overlying supposed confining layer. Warm spots indicate either more rapid or more prolonged flow locally. T-h and T-mice data show the highest temperatures coincided with high salinity fluids. C1 US GEOL SURVEY,DENVER,CO 80225. RP WALTON, AW (reprint author), UNIV KANSAS,DEPT GEOL,LAWRENCE,KS 66045, USA. NR 66 TC 10 Z9 10 U1 1 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0016-7835 J9 GEOL RUNDSCH JI Geol. Rundsch. PD SEP PY 1995 VL 84 IS 3 BP 535 EP 551 DI 10.1007/s005310050023 PG 17 WC Geosciences, Multidisciplinary SC Geology GA RZ213 UT WOS:A1995RZ21300009 ER PT J AU GEHRELS, GE DICKINSON, WR ROSS, GM STEWART, JH HOWELL, DG AF GEHRELS, GE DICKINSON, WR ROSS, GM STEWART, JH HOWELL, DG TI DETRITAL ZIRCON REFERENCE FOR CAMBRIAN TO TRIASSIC MIOGEOCLINAL STRATA OF WESTERN NORTH-AMERICA SO GEOLOGY LA English DT Article ID PALEOZOIC CONTINENTAL-MARGIN; CANADIAN CORDILLERA; UNITED-STATES; GEOCHRONOLOGY; EVOLUTION; BASEMENT; OROGEN AB U-Pb analyses of 656 single zircon grains from Cambrian to Triassic miogeoclinal strata provide a latitudinal and temporal reference for the ages of grains that accumulated along the western margin of North America, Comparisons between this detrital zircon reference and the ages of grains in potentially displaced terranes outboard (west) of the miogeocline should help establish when the terranes first arrived in sedimentary proximity to western North America, North-south variations in the ages of grains in Cambrian and Devonian to Triassic strata, which reflect the north-south changes in the age of cratonal rocks near the margin, should also help place constraints on a terrane's paleolatitude during these time periods, The technique cannot be used to determine paleolatitude during Ordovician time, however, because miogeoclinal strata from northern Canada to northern Mexico are dominated by grains shed from the Peace River arch (northwestern Canada). C1 GEOL SURVEY CANADA,CALGARY,AB T2L 2A7,CANADA. US GEOL SURVEY,MENLO PK,CA 94025. RP GEHRELS, GE (reprint author), UNIV ARIZONA,DEPT GEOSCI,TUCSON,AZ 85721, USA. NR 27 TC 136 Z9 138 U1 3 U2 15 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 1995 VL 23 IS 9 BP 831 EP 834 DI 10.1130/0091-7613(1995)023<0831:DZRFCT>2.3.CO;2 PG 4 WC Geology SC Geology GA RT701 UT WOS:A1995RT70100016 ER PT J AU HAYNES, JT MELSON, WG KUNK, MJ AF HAYNES, JT MELSON, WG KUNK, MJ TI COMPOSITION OF BIOTITE PHENOCRYSTS IN ORDOVICIAN TEPHRAS CASTS DOUBT ON THE PROPOSED TRANS-ATLANTIC CORRELATION OF THE MILLBRIG K-BENTONITE (UNITED-STATES) AND THE KINNEKULLE K-BENTONITE (SWEDEN) SO GEOLOGY LA English DT Article ID NORTH-AMERICA AB Biotite phenocryst compositions in three thick, widespread Ordovician K-bentonites, the Deicke and Millbrig from Big Ridge, Alabama, and the Kinnekulle from Mossen, Vastergotland, Sweden, fall into three distinct groups, and so the proposed intercontinental correlation of the Millbrig and the Kinnekulle is suspect. Because the biotites are nearly pristine compositionally, electron microprobe analyses provide a precise geochemical fingerprint of each bed. Millbrig and Kinnekulle biotites contain more FeO* and MnO and less MgO and TiO2 than do Deicke biotites, Millbrig biotites contain more MgO and less TiO2 than Kinnekulle biotites, and Kinnekulle biotites contain appreciably more Al2O3 than either Deicke or Millbrig biotites. Each of these tephras was unmistakably the product of a gigantic explosive volcanic eruption, but the differences in phenocryst chemistry point to derivation from three compositionally different magma batches. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP HAYNES, JT (reprint author), NATL MUSEUM NAT HIST,MRC 119,SMITHSONIAN INST,DEPT MINERAL SCI,WASHINGTON,DC 20560, USA. NR 17 TC 33 Z9 38 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 1995 VL 23 IS 9 BP 847 EP 850 DI 10.1130/0091-7613(1995)023<0847:COBPIO>2.3.CO;2 PG 4 WC Geology SC Geology GA RT701 UT WOS:A1995RT70100020 ER PT J AU OSTERKAMP, WR HUPP, CR SCHENING, MR AF OSTERKAMP, WR HUPP, CR SCHENING, MR TI LITTLE-RIVER REVISITED - 35 YEARS AFTER HACK AND GOODLETT SO GEOMORPHOLOGY LA English DT Article; Proceedings Paper CT 26th Binghamton Symposium in Geomorphology CY OCT 06-08, 1995 CL BINGHAMTON, NY ID VIRGINIA; FLOODS AB In possibly the first detailed study to relate geomorphology, vegetation, and hydrology at a watershed scale, Hack and Goodlett (1960) documented variation in the eastern forest with topograhic positions of cove, side slope, and nose. Runoff identified as convergent, parallel, or divergent, supported forest types, respectively, of northern hardwood, oak, and yellow pine. The study, conducted in the Little River Basin of northwestern Virginia, also described effects on landforms and vegetation of a catastrophic flood that occurred in June, 1949. Field investigations, conducted nearly 4 decades later, review selected parts of the study by Hack and Goodlett (1960). Replicate data provide a basis to evaluate interpretations of Hack and Goodlett, to document geomorphic change within the Little River Basin since the 1949 flood, and to identify vegetation change in uplands and bottomlands. Results suggest that change to hillslope landforms has been minor since 1949, but that changes have occurred to the Little River and its tributaries, seemingly during flow events of 1952, 1955, and 1985. Change in areal extent of forest types was not detected. Change in the relative abundances of dominant species may have resulted from 20th-century fire suppression. C1 US GEOL SURVEY,RESTON,VA 22092. RP OSTERKAMP, WR (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 46 TC 16 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 1995 VL 13 IS 1-4 BP 1 EP 20 DI 10.1016/0169-555X(95)00063-B PG 20 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA RW295 UT WOS:A1995RW29500002 ER PT J AU JOHNSON, WC DIXON, MD SIMONS, R JENSON, S LARSON, K AF JOHNSON, WC DIXON, MD SIMONS, R JENSON, S LARSON, K TI MAPPING THE RESPONSE OF RIPARIAN VEGETATION TO POSSIBLE FLOW REDUCTIONS IN THE SNAKE RIVER, IDAHO SO GEOMORPHOLOGY LA English DT Article; Proceedings Paper CT 26th Binghamton Symposium in Geomorphology CY OCT 06-08, 1995 CL BINGHAMTON, NY ID SOUTHERN ALBERTA; MISSOURI RIVER; FOREST; FLOODPLAIN; DYNAMICS; STREAM; COTTONWOOD; WATERFOWL; SURVIVAL; WETLANDS AB This study was initiated to determine the general effects of potential flow reductions in the middle Snake River (Swan Falls Dam downstream to the Idaho-Oregon border) on its riparian vegetation. Considerable water from the river is currently used to irrigate the adjacent Snake River Plain, and increased demand for water in the future is likely. The problem was subdivided into several research components including: field investigation of the existing riparian vegetation and river environment, hydrological modeling to calculate the effects of one flow scenario on hydrological regime, and integration of vegetation and hydrological modeling results with a Geographic Information System (GIS) to map the riverbed, island, and bank conditions under the scenario flow, Field work was conducted in summer 1990. Riparian vegetation along 40 U.S. Geological Survey cross-sections was sampled at approximately 1.25 mile intervals within the 50 mile long study area. Cross-section and flow data were provided by the U.S. Geological Survey, GIS mapping of land/water cover using ARC/INFO was based on 1987 aerial photographs. Riverbed contour maps were produced by linking cross-section data, topographic contouring software (ANUDEM),and GIS, The maps were used to spatially display shallow areas in the channel likely to become vegetated under reduced flow conditions. The scenario would reduce flow by approximately 20% (160 MAF) and lower the river an average of 0.5 ft. The scenario flow could cause a drop in the elevation of the riparian zone comparable to the drop in mean river level and expansion of the lower riparian zone into shallow areas of the channel, The GIS maps showed that the shallow areas of the channel more likely to become vegetated under the scenario flow are located in wide reaches near islands. Some possible ecological consequences of the scenario flow include a greater area of riparian habitat, reduced flow velocity and sedimentation in shallow channels leading to channel deactivation, increased island visitation and nest predation by predatory mammals due to loss of a water barrier between some islands and banks, and larger populations of alien plant species in the new riparian vegetation. C1 SIMONS & ASSOCIATES INC,FT COLLINS,CO 80525. US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD. RP JOHNSON, WC (reprint author), S DAKOTA STATE UNIV,DEPT HORT FORESTRY LANDSCAPE & PARKS,BROOKINGS,SD 57007, USA. RI Dixon, Mark/F-2641-2011 OI Dixon, Mark/0000-0002-0345-5655 NR 63 TC 37 Z9 38 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 1995 VL 13 IS 1-4 BP 159 EP 173 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA RW295 UT WOS:A1995RW29500012 ER PT J AU MCKENNEY, R JACOBSON, RB WERTHEIMER, RC AF MCKENNEY, R JACOBSON, RB WERTHEIMER, RC TI WOODY VEGETATION AND CHANNEL MORPHOGENESIS IN LOW-GRADIENT, GRAVEL-BED STREAMS IN THE OZARK PLATEAUS, MISSOURI AND ARKANSAS SO GEOMORPHOLOGY LA English DT Article; Proceedings Paper CT 26th Binghamton Symposium in Geomorphology CY OCT 06-08, 1995 CL BINGHAMTON, NY ID RIVER; EXAMPLES; FEATURES; FORM AB Woody vegetation affects channel morphogenesis in Ozark streams of Missouri and Arkansas by increasing local roughness, increasing bank strength, providing sedimentation sites, and creating obstructions to flow. Variations in physiographic controls on channel morphology result in systematic changes in vegetation patterns and geomorphic functions with increasing drainage basin area, In upstream reaches, streams have abundant bedrock control and bank heights that typically are less than or equal to the rooting depth of trees. In downstream reaches where valleys are wider and alluvial banks are higher vegetation has different geomorphic functions, At drainage areas of greater than 100-200 km(2), Ozarks streams are characterized by longitudinally juxtaposed reaches of high and low lateral channel migration rates, referred to as disturbance reaches and stable reaches, respectively. Whereas stable reaches can develop stable forested floodplains (if they are not farmed), disturbance reaches are characterized by dynamic vegetation communities that interact with erosion and deposition processes. Disturbance reaches can be subdivided into low-gradient and high-gradient longitudinal zones. Low-energy zones are characterized by incremental, unidirectional lateral channel migration and deposition of gravel and sand bars. The bars are characterized by prominent bands of woody vegetation and ridge and swale topography. Channel monitoring data indicate that densely vegetated bands of woody vegetation formed depositional sites during bedload-transporting events. The same floods caused up to 20 m of erosion of adjacent cutbanks, scoured non-vegetated areas between vegetation bands, and increased thalweg depth and definition, In high-energy (or riffle) zones, channel movement is dominantly by avulsion. In these zones, vegetation creates areas of erosional resistance that become temporary islands as the channel avulses around or through them, Woody vegetation on islands creates steep, root-defended banks that contribute to narrow channels with high velocities. Calculation of hydraulic roughness from density and average diameter of woody vegetation groups of different ages indicates that flow resistance provided by vegetation decreases systematically with group age, mainly through decreasing stem density. If all other factors remain constant, the stabilizing effect of a group of woody vegetation on a gravel bar decreases with vegetation age. C1 US GEOL SURVEY,ROLLA,MO. CARLETON COLL,NORTHFIELD,MN 55057. RP MCKENNEY, R (reprint author), PENN STATE UNIV,104 DAVEY LAB,UNIVERSITY PK,PA 16802, USA. NR 40 TC 91 Z9 93 U1 2 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 1995 VL 13 IS 1-4 BP 175 EP 198 DI 10.1016/0169-555X(95)00034-3 PG 24 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA RW295 UT WOS:A1995RW29500013 ER PT J AU HUPP, CR OSTERKAMP, WR HOWARD, AD AF HUPP, CR OSTERKAMP, WR HOWARD, AD TI UNTITLED - PREFACE SO GEOMORPHOLOGY LA English DT Editorial Material C1 US GEOL SURVEY,TUCSON,AZ 85745. UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. RP HUPP, CR (reprint author), US GEOL SURVEY,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. NR 9 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 1995 VL 13 IS 1-4 BP R7 EP R8 DI 10.1016/0169-555X(95)90009-I PG 2 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA RW295 UT WOS:A1995RW29500001 ER PT J AU LIU, PC HARTZELL, S STEPHENSON, W AF LIU, PC HARTZELL, S STEPHENSON, W TI NONLINEAR MULTIPARAMETER INVERSION USING A HYBRID GLOBAL SEARCH ALGORITHM - APPLICATIONS IN REFLECTION SEISMOLOGY SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE INVERSION; INVERSE PROBLEM; SEISMIC REFLECTION ID WAVE-FORM INVERSION; RESIDUAL STATICS ESTIMATION; GENETIC ALGORITHMS; OPTIMIZATION AB Many interesting inverse problems in geophysics are non-linear and multimodal. Parametrization of these problems leads to an objective function, or measure of agreement between data and model predictions, that has a complex topography with many local minima. Optimization algorithms that rely on local gradients in the objective function or that search the model space locally may become trapped in these local minima. By combining simulated annealing with the downhill simplex method, a hybrid global search algorithm is presented in this paper for non-linear, multimodal, inverse problems. The hybrid algorithm shares the advantages of both local search methods that perform well if the local model is suitable, and global methods that are able to explore efficiently the full model space. The hybrid algorithm also utilizes a larger and more complex memory to store information on the objective function than simulated annealing algorithms. The effectiveness of this new scheme is evaluated in three problems: minimization of the multidimensional Rosenbrock function, non-linear, 1-D, acoustic waveform inversion, and residual statics. The performance of the hybrid algorithm is compared with simulated annealing and genetic algorithms and is shown to converge more rapidly and to have a higher success rate of locating the global minimum for the cases investigated. C1 US GEOL SURVEY,EARTHQUAKE & LANDSLIDE HAZARDS BRANCH,DENVER,CO 80225. RP LIU, PC (reprint author), CHINESE ACAD SCI,INST GEOPHYS,BOX 9701,BEIJING 100101,PEOPLES R CHINA. NR 25 TC 51 Z9 63 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 1995 VL 122 IS 3 BP 991 EP 1000 DI 10.1111/j.1365-246X.1995.tb06851.x PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RU035 UT WOS:A1995RU03500023 ER PT J AU GREENE, EA RAHN, PH AF GREENE, EA RAHN, PH TI LOCALIZED ANISOTROPIC TRANSMISSIVITY IN A KARST AQUIFER SO GROUND WATER LA English DT Article ID CARBONATE AB Maps of cave passageways in the outcrop area of the uplifted Madison Limestone in the Black Hills, South Dakota, show that principal cavern development is oriented in the major direction of ground-water flow, roughly radial to the Black Hills, Fracture-trace analysis and measuremnt of joints in the Wind Cave area show that these orientations coincide with cave passageways. Aquifer testing at Rapid City indicates that a local principal transmissivity tenser is oriented in the direction of cave development and along the strikes of bedding-plane fractures, This indicates that much of the permeability of the Madison aquifer is modern karst (post-Laramide-Orogeny). From the above, we conclude that a localized anisotropic permeability (principal direction of transmissivity) is developed by ground water flowing through fractures, dissolving the rock, and producing dissolution-enhanced conduits along the direction of ground-water flow, This localized principal direction of transmissivity can be deduced from analysis of the potentiometric surface, stream-aquifer hydrographs, mapped cave passageways, aquifer tests, fracture traces, and measurements of joints in the field. C1 S DAKOTA SCH MINES & TECHNOL,DEPT GEOL & GEOL ENGN,RAPID CITY,SD 57701. RP GREENE, EA (reprint author), US GEOL SURVEY,931 NATL CTR,RESTON,VA 22092, USA. NR 25 TC 17 Z9 17 U1 0 U2 2 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1995 VL 33 IS 5 BP 806 EP 816 DI 10.1111/j.1745-6584.1995.tb00028.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RT130 UT WOS:A1995RT13000014 ER PT J AU BROOKS, GR KINDINGER, JL PENLAND, S WILLIAMS, SJ MCBRIDE, RA AF BROOKS, GR KINDINGER, JL PENLAND, S WILLIAMS, SJ MCBRIDE, RA TI EAST LOUISIANA CONTINENTAL-SHELF SEDIMENTS - A PRODUCT OF DELTA REWORKING SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE DELTAIC SEDIMENTATION; SHELF DEVELOPMENT; MISSISSIPPI RIVER DELTA; AND NEARSHORE PROCESSES ID MISSISSIPPI AB Data from 77 vibracores were integrated with 6,700 line-km of high-resolution seismic reflection profiles collected off the eastern Louisiana coast in the region of the St. Bernard Delta, the first of the Holocene highstand deltas of the Mississippi River. Seismic facies and sediment facies were integrated in order to establish the stratigraphic details within this relict delta. Results provide a regional geologic framework from which comparisons can be made with other areas. Holocene deposits in the study area overlie a heavily dissected surface interpreted to represent a lowstand erosional surface. Resting on this surface is a thin unit of relatively clean, quartz sand interpreted to have been deposited during early transgression. This unit is overlain by sediments of the St. Bernard Delta, a seaward-prograding. coarsening-upward wedge of sands and muds that contain vertically-stacked unite of deltaic succession. Two or more prograding units separated by an unconformity, delineated from regional seismic profiles, may represent laterally shifting subdelta lobes. Surficial sediments consist of a thin unit of sands and muds derived from and reflecting the individual subenvirons of the underlying delta. Holocene inner-shelf development off eastern Louisiana has been controlled by relative sea-level rise and sediment supply. Sediment supply and deposition are a product of delta progradation and delta lobe switching. The modern shelf configuration and surficial sediment distribution patterns reflect reworking of underlying deltaic deposits. The lack of modern sediment input helps to maintain the imprint of this ancient delta on the modern shelf surface. C1 US GEOL SURVEY,ST PETERSBURG,FL 33711. LOUISIANA STATE UNIV,INST COASTAL STUDIES,BATON ROUGE,LA 70803. US GEOL SURVEY,RESTON,VA 22902. RP BROOKS, GR (reprint author), ECKERD COLL,DEPT MARINE SCI,ST PETERSBURG,FL 33711, USA. NR 10 TC 10 Z9 10 U1 0 U2 3 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 1995 VL 11 IS 4 BP 1026 EP 1036 PG 11 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA TB661 UT WOS:A1995TB66100006 ER PT J AU SALLENGER, AH LIST, JH GELFENBAUM, G STUMPF, RP HANSEN, M AF SALLENGER, AH LIST, JH GELFENBAUM, G STUMPF, RP HANSEN, M TI LARGE WAVE AT DAYTONA-BEACH, FLORIDA, EXPLAINED AS A SQUALL-LINE SURGE SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE FREAK WAVES; OVERWASH; FORCED WAVE; WAVE RUNUP AB On a dear calm evening during July 1992, an anomalously large wave, reportedly 6 m high, struck the Daytona Beach, Florida area. We hypothesize that a squall line and associated pressure jump, traveling at the speed of a free gravity wave, coupled resonantly with the sea surface forming the large wave or ''squall-line surge.'' The wave was forced along the length of the squall line, with the greatest amplitude occurring at the water depth satisfying the resonant condition. Radar observations showed a strong squall line moving at a steady speed for several hundred kilometers parallel, to the coast from Georgia towards central Florida. The squall line dissipated 10 inn north of Daytona Beach; any forced wave would then propagate freely and retract. Wave refraction analyses predict a longshore distribution of wave heights consistent with field measurements of maximum wave runup. RP SALLENGER, AH (reprint author), US GEOL SURVEY,CTR COASTAL GEOL & REG MARINE STUDIES,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 8 TC 17 Z9 17 U1 0 U2 2 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 1995 VL 11 IS 4 BP 1383 EP 1388 PG 6 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA TB661 UT WOS:A1995TB66100037 ER PT J AU SEILER, RL AF SEILER, RL TI PREDICTION OF AREAS WHERE IRRIGATION DRAINAGE MAY INDUCE SELENIUM CONTAMINATION OF WATER SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article AB The U.S. Department of the Interior has investigated 25 areas in the western USA to determine whether irrigation drainage has caused harmful effects on wildlife or has reduced subsequent beneficial uses of the water. A database of chemical analyses of water, sediment, and biota from the 25 areas was created and supplemented with geologic, climatologic, and hydrologic data. The data were evaluated to identify common features among study areas and principal factors that result in Se contamination of water in lakes, ponds, and streams downgradient of irrigated areas. From the analysis of data, a decision tree that uses readily available geologic, climatologic, and hydrologic data was derived for use by resource managers as a screening tool to predict the likelihood that irrigation drainage will result in Se contamination in areas of the western USA. Irrigation in areas that are not associated with marine sedimentary rocks of late Cretaceous age is unlikely to cause Se contamination. Irrigation in very arid areas that are associated with these Cretaceous sediments Is almost certain to cause Se contamination if the irrigation water drains to terminal lakes and ponds. The likelihood that an area will be contaminated with Se because of irrigation drainage can change, particularly with changes in precipitation. During normal or wet periods, Se contamination may not occur in an area, even though it has seleniferous soils, but reduced water deliveries during a drought in such an area may result in Se contamination. RP SEILER, RL (reprint author), US GEOL SURVEY,333 W NYE LANE,CARSON CITY,NV 89706, USA. NR 17 TC 20 Z9 20 U1 0 U2 2 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 1995 VL 24 IS 5 BP 973 EP 979 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA RV384 UT WOS:A1995RV38400026 ER PT J AU Flint, PL MacCluskie, MC AF Flint, PL MacCluskie, MC TI A device for simultaneously measuring nest attendance and nest temperature in waterfowl SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article AB Previous studies of waterfowl have measured nest attendance and nest temperature separately using a variety of methods. A device was developed that monitors nest attendance and temperature simultaneously. The device consists of an artificial egg with a microswitch that records nest attendance and a thermistor probe that records temperature. Data are stored in a single-channel data logger. The device described measures the length of incubation breaks, and nest cooling and warming rates. C1 UNIV ALASKA FAIRBANKS,DEPT BIOL & WILDLIFE,FAIRBANKS,AK 99775. UNIV ALASKA FAIRBANKS,INST ARCTIC BIOL,FAIRBANKS,AK 99775. RP Flint, PL (reprint author), US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,NATL BIOL SERV,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. NR 5 TC 16 Z9 16 U1 0 U2 4 PU ASSOC FIELD ORNITHOLOGISTS PI BELOIT PA BELOIT COLLEGE, DEPT BIOLOGY, 700 COLLEGE ST, BELOIT, WI 53511 SN 0273-8570 J9 J FIELD ORNITHOL JI J. Field Ornithol. PD FAL PY 1995 VL 66 IS 4 BP 515 EP 521 PG 7 WC Ornithology SC Zoology GA TL751 UT WOS:A1995TL75100008 ER PT J AU OCOLA, LC LUETGERT, JH ALDRICH, LT MEYER, RP HELSEY, CE AF OCOLA, LC LUETGERT, JH ALDRICH, LT MEYER, RP HELSEY, CE TI VELOCITY STRUCTURE OF THE COASTAL REGION OF SOUTHERN PERU FROM SEISMIC-REFRACTION WIDE-ANGLE REFLECTION DATA SO JOURNAL OF GEODYNAMICS LA English DT Article ID CRUSTAL STRUCTURE; CENTRAL ANDES; PLATE; TECTONICS; TRENCH AB Refraction information from three separate experiments in southern Peru has been integrated to produce two reversed profiles and five unreversed profiles of travel-time data for the coastal region of the area. A fan of records NW of Atico, at ranges beyond the Pn crossover show azimuthal variability in their arrival times and waveform. These are interpreted to indicate local and large variations in the velocity structure in this region and impose limitations of the possible interpretation of the results. The two reversed profiles and one split profile sample about 1000 km of the coast, from Lima tb the Chilean border. The data have been fitted with two-dimensional models with plane dipping interfaces, and have been found to be well represented by such models. Since profiles sample different azimuths, one obtains a quasi-three-dimensional picture of the region which includes gently dipping (about 5 degrees to the NE), interfaces. The reversed profiles are best fit by a model which includes: (a) a thin upper crustal layer with velocities of 5.4-6.0 km/s; (b) a fairly thick 6.5 km/s layer; (c) a relatively thick layer of unusually high crustal velocity, 7.3 km/s, which is commonly found among the first arrivals and may be interpreted from later arrivals in all the record sections; and finally, (d) a mantle velocity of 8 km/s. C1 UNIV WISCONSIN,DEPT GEOL & GEOPHYS,MADISON,WI 53706. INST GEOFIS,LIMA,PERU. US GEOL SURVEY,MENLO PK,CA 94025. CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,WASHINGTON,DC 20015. UNIV HAWAII,HAWAII INST GEOPHYS,HONOLULU,HI 96822. NR 38 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD SEP PY 1995 VL 20 IS 1 BP 1 EP 30 DI 10.1016/0264-3707(94)00026-R PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC762 UT WOS:A1995RC76200002 ER PT J AU SCHUSTER, RL MEYER, W AF SCHUSTER, RL MEYER, W TI POTENTIAL FOR SEEPAGE EROSION OF LANDSLIDE DAM - CLOSURE SO JOURNAL OF GEOTECHNICAL ENGINEERING-ASCE LA English DT Discussion C1 US GEOL SURVEY,HONOLULU,HI 96813. RP SCHUSTER, RL (reprint author), US GEOL SURVEY,MAIL STOP 966,POB 25046,DENVER,CO 80225, USA. NR 9 TC 0 Z9 0 U1 1 U2 3 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9410 J9 J GEOTECH ENG-ASCE JI J. Geotech. Eng.-ASCE PD SEP PY 1995 VL 121 IS 9 BP 674 EP 675 DI 10.1061/(ASCE)0733-9410(1995)121:9(674) PG 2 WC Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA RQ981 UT WOS:A1995RQ98100010 ER PT J AU LICHTY, RW KARLINGER, MR AF LICHTY, RW KARLINGER, MR TI SPATIAL TRENDS IN PEARSON TYPE-III STATISTICAL PARAMETERS SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID REGIONAL HYDROLOGIC ANALYSIS; SKEW COEFFICIENT; FLOOD FREQUENCY AB Spatial trends in the statistical parameters (mean, standard deviation, and skewness coefficient) of a Pearson Type III distribution of the logarithms of annual flood peaks for small rural basins (less than 90 km(2)) are delineated using a climate factor, C-T (T = 2-, 25-, and 100-yr recurrence intervals) which quantifies the effects of long-term climatic data (rainfall and pan evaporation) on observed T-yr floods, The statistical parameters are computed from gridded estimates of the geographically varying climate factors and regression models relating at-site T-yr floods as a function of drainage area, climate factor, hydrograph shape, and infiltration. Spatial portrayals, covering a large part of the United States east of the 105th meridian, are presented for averaged statistical parameters and their variability obtained using data from a sample of 200 small basins scattered over 12 states. Maps showing trends in average parameter values demonstrate the geographically varying influence of climate on the magnitude of Pearson Type III statistical parameters. The spatial trends in variability of the parameter values characterize the sensitivity of statistical parameters to the interaction of basin-runoff characteristics (hydrology) and climate. RP LICHTY, RW (reprint author), US GEOL SURVEY,WRD,MS 418,DENVER,CO 80225, USA. NR 17 TC 0 Z9 0 U1 1 U2 2 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD SEP PY 1995 VL 121 IS 9 BP 672 EP 678 DI 10.1061/(ASCE)0733-9429(1995)121:9(672) PG 7 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA RQ819 UT WOS:A1995RQ81900007 ER PT J AU COBBAN, WA KENNEDY, WJ AF COBBAN, WA KENNEDY, WJ TI MAASTRICHTIAN AMMONITES CHIEFLY FROM THE PRAIRIE BLUFF CHALK IN ALABAMA AND MISSISSIPPI SO JOURNAL OF PALEONTOLOGY LA English DT Review ID CRETACEOUS-TERTIARY BOUNDARY; HETEROMORPH AMMONITES; WESTERN-AUSTRALIA; SOUTH-INDIA; PONDICHERRY; BACULITES; INTERIOR AB The Prairie Bluff Chalk of Alabama and Mississippi yields a diverse ammonite fauna of Maastrichtian age. Twenty-eight species, of which three are new, are recorded herein: Pseudophyllites indra (Forbes, 1846), Hauericeras rembda (Forbes, 1846), Pachydiscus (Pachydiscus) maconensis n. sp., P. (P.) cf. gollevillensis (d'Orbigny, 1850), P. (P.) jacquoti (Seunes, 1890), P. (P.) egertoni (Forbes, 1846), Sphenodiscus lobatus (Tuomey, 1854), S. pleurisepta (Conrad, 1857), Coahuilites sheltoni Bose, 1928, Nostoceras (Nostoceras) alternatum (Tuomey, 1854), N. (N.) mendryki Cobban, 1974a, N. (N.) magdadiae Lefeld and Uberna, 1991, N. (N.) irregulare n. sp., Glyptoxoceras torquatum (Morton, 1834), Glyptoxoceras sp. A, Glyptoxoceras? sp., Baculites lomaensis Anderson, 1958, Baculites spp. A-C, Eubaculites labyrinthicus (Morton, 1834), E. carinatus (Morton, 1834), Baculites? trabeatus (Morton, 1834), Trachybaculites columna (Morton, 1834), Discoscaphites conradi (Morton, 1834), D. gulosus (Morton, 1834), Jeletzkytes criptonodosus Riccardi, 1983, Trachyscaphites alabamensis n. sp., and T. yorkensis (Stephenson, 1941). One genus, Trachybaculites, is new. The bulk of the fauna can be referred to a Discoscaphites conradi assemblage zone, but some elements in the fauna are significantly older. C1 UNIV OXFORD MUSEUM,GEOL COLLECT,OXFORD OX1 3PW,ENGLAND. RP COBBAN, WA (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MAIL STOP 919,DENVER,CO 80225, USA. NR 142 TC 11 Z9 13 U1 0 U2 1 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD SEP PY 1995 VL 69 IS 5 SU S BP 1 EP 40 PN 3 PG 40 WC Paleontology SC Paleontology GA RY180 UT WOS:A1995RY18000001 ER PT J AU ANDERSEN, DE AF ANDERSEN, DE TI PRODUCTIVITY, FOOD-HABITS, AND BEHAVIOR OF SWAINSONS HAWKS BREEDING IN SOUTHEAST COLORADO SO JOURNAL OF RAPTOR RESEARCH LA English DT Article DE BUTEO SWAINSONI; COLORADO; FOOD HABITS; HOME RANGE; REPRODUCTION; SWAINSONS HAWK ID CHANGING PREY DENSITIES; NEST SUCCESS; POPULATIONS; ECOLOGY; SITE AB From 1984 through 1988, I studied Swainson's hawk (Buteo swainsoni) ecology during the breeding season on the Pinon Canyon Maneuver Site (PCMS) in southeast Colorado. The number of nesting attempts located and monitored annually ranged from four in 1984, to 22 in 1987. Nests used by Swainson's hawks were located predominantly in one-seed juniper (Juniperus monosperma) or cottonwood (Populus spp.) trees. Traditional nesting success estimates averaged 0.64 and ranged from 0.42 in 1985 to 1.00 in 1984. Mayfield estimates of nesting success ranged from 0.27 (1988) to 1.00 (1984). Based on prey remains collected at nest sites, food deliveries to nestlings consisted primarily of small birds (50%) and mammals (45%), and diet breadth over the 5-yr study period was high. Minimum-convex-polygon home-range size of radio-marked adults during the late-nestling and post-fledging period averaged 21.2 km(2) in 1985 and 27.3 km(2) in 1986, with males exhibiting larger home ranges than females (P = 0.15) across years. Compared with other breeding Swainson's hawk populations, breeding area reoccupancy among years on the PCMS was moderately high, home ranges during the late-nestling and post-fledging periods were large, and ground-nesting birds were important in the breeding-season diet. C1 UNIV WISCONSIN,DEPT WILDLIFE ECOL,MADISON,WI 53706. US FISH & WILDLIFE SERV,COLORADO FISH & WILDLIFE ASSISTANCE OFF,GOLDEN,CO 80401. NR 56 TC 8 Z9 8 U1 0 U2 5 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD SEP PY 1995 VL 29 IS 3 BP 158 EP 165 PG 8 WC Ornithology SC Zoology GA RX347 UT WOS:A1995RX34700002 ER PT J AU GARCELON, DK SLATER, GL DANILSON, CD HELM, RC AF GARCELON, DK SLATER, GL DANILSON, CD HELM, RC TI COOPERATIVE NESTING BY A TRIO OF BALD EAGLES SO JOURNAL OF RAPTOR RESEARCH LA English DT Note DE BALD EAGLE; BREEDING; CALIFORNIA; HALIAEETUS LEUCOCEPHALUS; NEST HELPERS ID HAWK BUTEO-GALAPAGOENSIS; KINGFISHER CERYLE-RUDIS; REPRODUCTIVE SUCCESS; HELPERS; POLYANDRY C1 US FISH & WILDLIFE SERV,PORTLAND,OR 97232. RP GARCELON, DK (reprint author), INST WILDLIFE STUDIES,POB 1104,ARCATA,CA 95521, USA. NR 28 TC 3 Z9 4 U1 1 U2 1 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD SEP PY 1995 VL 29 IS 3 BP 210 EP 213 PG 4 WC Ornithology SC Zoology GA RX347 UT WOS:A1995RX34700012 ER PT J AU TOY, TJ OSTERKAMP, WR AF TOY, TJ OSTERKAMP, WR TI THE APPLICABILITY OF RUSLE TO GEOMORPHIC STUDIES SO JOURNAL OF SOIL AND WATER CONSERVATION LA English DT Article; Proceedings Paper CT International Symposium on Water Research and Management in Semiarid Environments CY NOV 01-03, 1994 CL TUCSON, AZ ID EROSION AB The Universal Soil Loss Equation (USLE) has been the best, most convenient technology for estimating soil loss in a wide variety of investigations. Recent revisions to USLE incorporated new knowledge and improved the versatility of the revised USLE (RUSLE). Following a brief description of the evolution and utilization of USLE, this presentation addresses the applicability of RUSLE in geomorphic research. In general, consideration of both temporal and spatial scales is essential for the appropriate application of RUSLE in geomorphic research. Soil-loss estimates may be extended into the past only so long as the environmental conditions remain virtually the same as those used in the computations. Soil-loss estimates are likely to be of satisfactory accuracy at spatial scales ranging from landscape profiles (hillslopes) up to small drainage basins in which there is minimal sediment storage. C1 US GEOL SURVEY,DESERT LAB,DIV WATER RESOURCES,NATL RES PROGRAM,TUCSON,AZ 85745. RP TOY, TJ (reprint author), UNIV DENVER,DEPT GEOG,DENVER,CO 80208, USA. NR 61 TC 8 Z9 9 U1 1 U2 3 PU SOIL WATER CONSERVATION SOC PI ANKENY PA 7515 N E ANKENY RD, ANKENY, IA 50021-9764 SN 0022-4561 J9 J SOIL WATER CONSERV JI J. Soil Water Conserv. PD SEP-OCT PY 1995 VL 50 IS 5 BP 498 EP 503 PG 6 WC Ecology; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA RX578 UT WOS:A1995RX57800022 ER PT J AU AGAR, SM KLITGORD, KD AF AGAR, SM KLITGORD, KD TI RIFT FLANK SEGMENTATION, BASIN INITIATION AND PROPAGATION - A NEOTECTONIC EXAMPLE FROM LAKE BAIKAL SO JOURNAL OF THE GEOLOGICAL SOCIETY LA English DT Article DE BAIKAL RIFT ZONE; DEFORMATION; NEOTECTONICS; SEGMENTATION; SEDIMENTARY BASINS ID EXTENDED CONTINENTAL LITHOSPHERE; STRUCTURAL EVOLUTION; SEISMIC DATA; ZONE; FAULTS; EARTHQUAKES; WASATCH; FRAMEWORK; EXTENSION; TECTONICS AB New surficial data (field, Landsat TM and topography) define morpho-tectonic domains and rift flank segmentation in the Ol'khon region of the Central Baikal rift. Deformation, drainage and depositional patterns indicate a change in the locus of active extension that may relate to a recent (<1 Ma) change in the kinematics of the Siberian plate boundary. The westwards migration of the border fault location has broadened the rift with concomitant shifts in depocentres. Within the hanging wall of the new western border fault, distinct segments control the location of drainage paths and syn-rift deposits. Morphology, sediment thicknesses and fault scarp amplitude indicate that a segmented rift flank graben has propagated southwards along the rift flank and is still actively fragmenting. These surficial data are used to constrain a model for the time-dependent topographic variations during progressive subsidence along a rift flank, involving the transfer of footwall units to hanging-wall domains. Rapid changes in border fault footwall relief in this model are associated with change in the active border fault location with widespread mass-wasting. The model shows that time-dependent histories need to be integrated with flexural uplift models for active normal faults. The active, syn-rift depositional systems of the Ol'khon region provide a valuable analogue for the early evolution of continental margins and the structural controls on syn-rift hydrocarbon sources and reservoirs. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP AGAR, SM (reprint author), NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60208, USA. NR 52 TC 33 Z9 33 U1 2 U2 4 PU GEOLOGICAL SOC PUBL HOUSE PI BATH PA UNIT 7, BRASSMILL ENTERPRISE CENTRE, BATH, AVON, ENGLAND BA1 3JN SN 0016-7649 J9 J GEOL SOC LONDON JI J. Geol. Soc. PD SEP PY 1995 VL 152 BP 849 EP 860 DI 10.1144/gsjgs.152.5.0849 PN 5 PG 12 WC Geosciences, Multidisciplinary SC Geology GA RR231 UT WOS:A1995RR23100013 ER PT J AU BOWERS, JE WEBB, RH RONDEAU, RJ AF BOWERS, JE WEBB, RH RONDEAU, RJ TI LONGEVITY, RECRUITMENT AND MORTALITY OF DESERT PLANTS IN GRAND-CANYON, ARIZONA, USA SO JOURNAL OF VEGETATION SCIENCE LA English DT Article DE DEMOGRAPHY; DESERT SHRUB; EPHEDRA; LARREA; LIFE-SPAN; OPUNTIA; REPEAT PHOTOGRAPHY AB The demography of woody desert plants along the Colorado River in Grand Canyon, Arizona, USA, was analyzed using 355 pairs of replicated photographs taken as long ago as 1872. Longevity, recruitment, and mortality were determined for 38 species characteristic of ungrazed desert scrub. Individual plants that survived 100 yr or more included Acacia greggii, Ambrosia dumosa, Atriplex canescens, A. confertifolia, Echinocactus polycephalus, Ephedra spp., Fouquieria splendens, Larrea tridentata, Lycium andersonii, Opuntia acanthocarpa, O. basilaris, O. erinacea, Pleuraphis rigida, and Yucca angustissima. This is the first evidence of long lifespan for most of these species, particularly the succulents. Most of the long-lived species registered overall increases in population during the past century. Only four species with lifespans greater than or equal to 100 yr had a net loss of individuals between 1889 and the present, and only two decreased between 1923 and the present. It seems likely that climatic fluctuations over the past century are largely responsible for these recruitment and mortality patterns; however, nurse plants, predation refuges and other biotic factors may also play a role. RP BOWERS, JE (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 0 TC 71 Z9 74 U1 2 U2 18 PU OPULUS PRESS UPPSALA AB PI KNIVSTA PA APELSINVAGEN 47, S 741 00 KNIVSTA, SWEDEN SN 1100-9233 J9 J VEG SCI JI J. Veg. Sci. PD SEP PY 1995 VL 6 IS 4 BP 551 EP 564 DI 10.2307/3236354 PG 14 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA TD404 UT WOS:A1995TD40400012 ER PT J AU Anderson, DK Damuth, J Bown, TM AF Anderson, DK Damuth, J Bown, TM TI Rapid morphological change in Miocene marsupials and rodents associated with a volcanic catastrophe in Argentina SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article ID SANTA-CRUZ-PROVINCE; MOUNT ST-HELENS; GENETIC VARIANCE; PHENOTYPIC EVOLUTION; FOSSIL PLATYRRHINES; PINTURAS FORMATION; FOUNDER EVENTS; BOTTLENECK; DIFFERENTIATION; INTEGRATION AB Large fossil samples collected from a continuous series of stratigraphic levels are ideal for studying the tempo and mode of phyletic evolution. Study of two such coeval mammalian lineages (caenolestoid marsupials and octodontoid rodents) from Miocene rocks of southern Argentina revealed marked, simultaneous changes in molar dimensions in both lineages. The changes occur across a 1.65-1.80 m thick tuff unit that covers a widespread bonebed. Geologic and taphonomic data indicate that the tuff unit marks the rapid (geologically instantaneous) burial of an ancient land surface by pyroclastic products of a single major volcanic eruption. This suggests that the morphological changes observed in the fossil mammal samples were associated with catastrophic reduction in population size or the local or regional extermination of small mammal populations. Samples of both Lineages showed changes in dental dimensions that are not simply the continuation of long-term morphological trends established before the volcanic event. Rapid ''jumps'' in morphology are seen in the opposite direction to longterm trends. The observed changes are consistent with responses to new selection pressures imposed by a strongly altered environment, and with the genetic and phenotypic phenomena associated with rapid and severe population reductions (''bottlenecks''). This is one example of the effect that geologically instantaneous environmental events can have upon evolving lineages, both immediately following the event and for geologically significant periods of time thereafter. Such morphological ''punctuations'' may easily occur without lineage splitting (cladogenesis). This suggests that traditional punctuated equilibrium theory may place too much emphasis on processes associated with speciation in the generation of macroevolutionary patterns. C1 UNIV CALIF SANTA BARBARA, DEPT BIOL SCI, SANTA BARBARA, CA 93106 USA. US GEOL SURVEY, PALEONTOL & STRATIG BRANCH, DENVER, CO 80225 USA. RP Anderson, DK (reprint author), ST NORBERT COLL, DIV NAT SCI, DE PERE, WI 54115 USA. NR 35 TC 11 Z9 11 U1 2 U2 13 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0272-4634 EI 1937-2809 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD SEP PY 1995 VL 15 IS 3 BP 640 EP 649 PG 10 WC Paleontology SC Paleontology GA UH151 UT WOS:A1995UH15100013 ER PT J AU GROSSMAN, JN MACPHERSON, GJ HSU, W ZINNER, EK AF GROSSMAN, JN MACPHERSON, GJ HSU, W ZINNER, EK TI PLAGIOCLASE-RICH OBJECTS IN THE UNGROUPED E3 CHONDRITE LEWIS-CLIFF-87234 - PETROLOGY AND ALUMINUM-MAGNESIUM ISOTOPIC DATA SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,RESTON,VA 22092. NATL MUSEUM NAT HIST,DEPT MINERAL SCI,WASHINGTON,DC 20560. WASHINGTON UNIV,MCDONNELL CTR SPACE SCI,ST LOUIS,MO 63130. NR 6 TC 5 Z9 5 U1 1 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 514 EP 514 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800073 ER PT J AU KING, TVV CALVIN, WM AF KING, TVV CALVIN, WM TI SINGLE VS CUMULATIVE GRAIN-SIZE DISTRIBUTION - EFFECTS ON THEORETICAL REFLECTANCE CALCULATIONS SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,FLAGSTAFF,AZ 86001. NR 0 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 527 EP 527 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800102 ER PT J AU KITA, NT MISAWA, K TATSUMOTO, M AF KITA, NT MISAWA, K TATSUMOTO, M TI LREE-RICH COMPONENT IN UREILITES - FURTHER EVIDENCE OF TERRESTRIAL CONTAMINATION SO METEORITICS LA English DT Meeting Abstract ID SM-ND; RB-SR; SYSTEMATICS C1 GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. KOBE UNIV,DEPT EARTH & PLANETARY SCI,KOBE 657,JAPAN. US GEOL SURVEY,DENVER,CO 80225. NR 7 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 528 EP 528 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800104 ER PT J AU KOEBERL, C REIMOLD, WU BRANDT, D POAG, CW AF KOEBERL, C REIMOLD, WU BRANDT, D POAG, CW TI CHESAPEAKE BAY CRATER, VIRGINIA - CONFIRMATION OF IMPACT ORIGIN SO METEORITICS LA English DT Meeting Abstract C1 UNIV VIENNA,INST GEOCHEM,A-1090 VIENNA,AUSTRIA. UNIV WITWATERSRAND,DEPT GEOL,JOHANNESBURG 2050,SOUTH AFRICA. US GEOL SURVEY,WOODS HOLE,MA 02543. NR 5 TC 2 Z9 2 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 528 EP 529 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800105 ER PT J AU POAG, CW AF POAG, CW TI GEOPHYSICAL SIGNATURE OF THE CHESAPEAKE BAY IMPACT CRATER (LATE EOCENE) SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,WOODS HOLE,MA 02543. NR 1 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 561 EP 562 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800173 ER PT J AU POAG, CW AF POAG, CW TI LATE EOCENE STAR-WARS - THE TOMS CANYON AND CHESAPEAKE BAY IMPACT CRATERS, US EAST-COAST SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,WOODS HOLE,MA 02543. NR 4 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 562 EP 562 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800174 ER PT J AU RIDLEY, WI PLUMLEE, GS DEBRAAL, JD REED, MH AF RIDLEY, WI PLUMLEE, GS DEBRAAL, JD REED, MH TI ALTERATION OF THE MARTIAN SURFACE THROUGH TIME - A REACTION-PATH MODELING APPROACH SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,GEOCHEM BRANCH,DENVER,CO 80225. UNIV OREGON,DEPT GEOL SCI,EUGENE,OR 97403. NR 3 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 565 EP 565 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800182 ER PT J AU ROBINSON, M BELL, J CHAPMAN, C CHENG, A GOLD, R MALIN, M MCFADDEN, L MURCHIE, S THOMAS, P VEVERKA, J WARREN, J AF ROBINSON, M BELL, J CHAPMAN, C CHENG, A GOLD, R MALIN, M MCFADDEN, L MURCHIE, S THOMAS, P VEVERKA, J WARREN, J TI NEAR MSI AND NIS - HIGH-RESOLUTION ORBITAL IMAGING AND SPECTROSCOPY OF THE ASTEROID 433-EROS SO METEORITICS LA English DT Meeting Abstract C1 CORNELL UNIV,ITHACA,NY. PLANETARY SCI INST,TUCSON,AZ. JOHNS HOPKINS UNIV,APPL PHYS LAB,BALTIMORE,MD. MALIN SPACE SCI SYST,SAN DIEGO,CA. UNIV MARYLAND,COLLEGE PK,MD. US GEOL SURVEY,FLAGSTAFF,AZ 86001. RI Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 0 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 566 EP 567 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800184 ER PT J AU RODDY, DJ SHOEMAKER, EM AF RODDY, DJ SHOEMAKER, EM TI METEOR CRATER (BARRINGER METEORITE CRATER), ARIZONA - SUMMARY OF IMPACT CONDITIONS SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. LOWELL OBSERV,FLAGSTAFF,AZ 86001. NR 4 TC 3 Z9 3 U1 0 U2 5 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 567 EP 567 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800185 ER PT J AU SHOEMAKER, EM RODDY, DJ MOORE, CB PFEILSTICKER, R CURLEY, CL DUNKELMAN, T KUERZEL, K TAYLOR, M SHOEMAKER, C DONNELLY, P AF SHOEMAKER, EM RODDY, DJ MOORE, CB PFEILSTICKER, R CURLEY, CL DUNKELMAN, T KUERZEL, K TAYLOR, M SHOEMAKER, C DONNELLY, P TI IMPACT CRATER IDENTIFIED ON THE NAVAJO NATION NEAR CHINLE, ARIZONA SO METEORITICS LA English DT Meeting Abstract C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. LOWELL OBSERV,FLAGSTAFF,AZ 86001. ARIZONA STATE UNIV,CTR METEORITE STUDIES,TEMPE,AZ 85287. NAVAJO ENVIRONM PROTECT AGCY,WINDOW ROCK,AZ 86515. US EPA,SAN FRANCISCO,CA 94105. ECOL & ENVIRONM INC,SAN FRANCISCO,CA 94105. NO ARIZONA UNIV,DEPT BIOL SCI,FLAGSTAFF,AZ 86011. NR 0 TC 0 Z9 0 U1 0 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD SEP PY 1995 VL 30 IS 5 BP 578 EP 579 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RR518 UT WOS:A1995RR51800207 ER PT J AU KVENVOLDEN, K AF KVENVOLDEN, K TI NATURAL-GAS HYDRATE OCCURRENCE AND ISSUES SO SEA TECHNOLOGY LA English DT Article RP KVENVOLDEN, K (reprint author), US GEOL SURVEY,DIV GEOL,PACIFIC MARINE GEOL BRANCH,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 0 TC 5 Z9 5 U1 1 U2 2 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD SEP PY 1995 VL 36 IS 9 BP 69 EP 74 PG 6 WC Engineering, Ocean SC Engineering GA RW458 UT WOS:A1995RW45800012 ER PT J AU HUNTINGTON, TG AF HUNTINGTON, TG TI CARBON SEQUESTRATION IN AN AGGRADING FOREST ECOSYSTEM IN THE SOUTHEASTERN USA SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID UNITED-STATES; ATMOSPHERIC CARBON; TEMPERATE FOREST; STORAGE; SOILS; CO2; BUDGET; CULTIVATION; DEPOSITION; PIEDMONT AB An analysis of C pools at the Panola Mountain Research Watershed (PMRW) near Atlanta, GA, indicates that aggrading forests in the U.S. Southeast are an important regional C sink. The forests in this area were cut in the early 1800s and the land was cultivated until the early 1900s, when farming was abandoned and forest regeneration began. Cultivation resulted in extensive erosion, which depleted soil C pools. The rate of soil C sequestration during the 70-yr period of forest regeneration was estimated to be between 0.34 (standard error [SE] = 0.12) and 0.79 (SE = 0.19) Mg C ha(-1) yr(-1). There is a large potential for continued C accumulation in the soil at PMRW based on the difference between current measured soil C pools of 82 Mg C ha(-1) at PMRW and 122 Mg C ha(-1) at the nearby ''undisturbed'' Fernbank Forest in Atlanta, GA. The rate of C sequestration in biomass at PMRW was 1.17 Mg C ha(-1) yr(-1) for the regeneration period, bringing the ecosystem total to between 1.81 and 2.26 Mg C ha(-1) yr(-1). Carbon sequestration in temperate forest ecosystems partially mitigates the effects of increased atmospheric loading of CO2. RP HUNTINGTON, TG (reprint author), US GEOL SURVEY,PEACHTREE BUSINESS CTR,SUITE 130,3039 AMWILER RD,ATLANTA,GA 30360, USA. OI Huntington, Thomas/0000-0002-9427-3530 NR 70 TC 49 Z9 60 U1 1 U2 17 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD SEP-OCT PY 1995 VL 59 IS 5 BP 1459 EP 1467 PG 9 WC Soil Science SC Agriculture GA RU917 UT WOS:A1995RU91700037 ER PT J AU ALBINO, GV JALAL, S CHRISTENSEN, K AF ALBINO, GV JALAL, S CHRISTENSEN, K TI NEOPROTEROZOIC MESOTHERMAL GOLD MINERALIZATION AT SUKHAYBARAT EAST MINE, SAUDI-ARABIA SO TRANSACTIONS OF THE INSTITUTION OF MINING AND METALLURGY SECTION B-APPLIED EARTH SCIENCE LA English DT Article ID ABITIBI GREENSTONE-BELT; INVISIBLE GOLD; SIGMA-MINE; SHIELD; EVOLUTION; BEARING; QUEBEC; VEINS AB The Sukhaybarat East gold deposit, which had preproduction reserves of 8 400 000 t at an average grade of 2.5 g/t Au, is located in the northeastern part of the Neoproterozoic Arabian Shield. It is hosted by a small diorite to tonalite stock (617 m.y.) and adjacent contact-metamorphosed siltstones of the Murdama group (670-655 m.y.). Gold ore is present in a moderately dipping zone that transects the host intrusion and in a smaller, vertical zone along one contact of the stock. The ore consists of ribboned to massive quartz veins and veinlets and altered and mineralized diorite, tonalite and hornfels. The veins include a conjugate set of moderately dipping shear veins and sub-horizontal extension veins. Arsenopyrite (<1 to 3-5 wt%) is the main opaque mineral, with much smaller amounts of pyrite and local traces of base-metal sulphides. Visible gold is extremely rare, and even microscopically visible gold is not common in unoxidized ore. Ore-related alteration includes zones of 'visual' alteration in which the host rocks are bleached as a result of the formation of carbonates, white mica and chlorite at the expense of biotite and hornblende. These zones are narrow (typically less than one to two vein widths), and some gold-bearing veins lack such envelopes. Some ore-grade material appears unaltered to the unaided eye ('cryptic' alteration) and lacks quartz veinlets, with disseminated arsenopyrite the only obvious indication that the rock is mineralized. The geological setting, ore mineralogy and geochemistry, together with the style of veining and alteration, indicate that the Sukhaybarat East gold deposit is a mesothermal gold deposit similar to those in Archaean to Mesozoic orogenic belts elsewhere in the world. The presence of Liquid CO2 in fluid inclusions is consistent with such a classification. The deposit formed during a period of north-south compression that followed most of the deformation and metamorphism in the region. Gold mineralization predated the emplacement of undeformed, shallow-level, alkalic granite intrusions. The alkalic intrusions probably postdate cratonization in the northeastern Arabian Shield, suggesting that gold mineralization at the Sukhaybarat East and nearby deposits may be related in time to the cratonization of accreted crust, as has been suggested for other mesothermal gold provinces. RP ALBINO, GV (reprint author), US GEOL SURVEY,POB 1488,JEDDAH 21431,SAUDI ARABIA. NR 46 TC 3 Z9 3 U1 0 U2 1 PU INST MINING METALLURGY PI LONDON PA 44 PORTLAND PLACE, LONDON, ENGLAND W1N 4BR SN 0371-7453 J9 T I MIN METALL B JI Tran. Inst. Min. Metall. Sect. B-App. Earth Sci. PD SEP-DEC PY 1995 VL 104 BP B157 EP B170 PG 14 WC Geosciences, Multidisciplinary SC Geology GA TC243 UT WOS:A1995TC24300001 ER PT J AU FERNANDEZ, IJ LAWRENCE, GB SON, YH AF FERNANDEZ, IJ LAWRENCE, GB SON, YH TI SOIL-SOLUTION CHEMISTRY IN A LOW-ELEVATION SPRUCE-FIR ECOSYSTEM, HOWLAND, MAINE SO WATER AIR AND SOIL POLLUTION LA English DT Article ID NORTHERN NEW-ENGLAND; FOREST SOILS; SURFACE WATERS; NITROGEN; MINERALIZATION; TEMPERATURE; DEPOSITION; LYSIMETER; STAND; USA AB Soil solutions were collected monthly by tension and zero-tension lysimeters in a low-elevation red spruce stand in east-central Maine from May 1987 through December 1992. Soil solutions collected by Oa tension lysimeters had higher concentrations of most constituents than the Oa zero-tension lysimeters. In Oa horizon soil solutions growing season concentrations for SO4, Ca, and Mg averaged 57, 43, and 30 mu mol L(-1) in tension lysimeters, and 43, 28, and 19 mu mol L(-1) in zero-tension lysimeters, respectively. Because tension lysimeters remove water held by the soil at tensions up to 10 kPa, solutions are assumed to have more time to react with the soil compared to freely draining solutions collected by zero-tension lysimeters. Solutions collected in the Bs horizon by both types of collectors were similar which was attributed to the frequency of time periods when the water table was above the Bs lysimeters. Concentrations of SO4 and NO3 at this site were lower than concentrations reported for most other eastern U.S. spruce-fir sites, but base cation concentrations fell in the same range. Aluminum concentrations in this study were also lower than reported for other sites in the eastern U.S. and Ca/Al ratios did not suggest inhibition of Ca uptake by roots. Concentrations of SO4, Ca, K, and Cl decreased significantly in both the Oa and Bs horizons over the 56-month sampling period, which could reflect decreasing deposition rates for sulfur and base cations, climatic influences, or natural variation. A longer record of measured fluxes will be needed to adequately define temporal trends in solution chemistry and their causes. C1 KOREA UNIV,DEPT FOREST RESOURCES,SEOUL 136701,SOUTH KOREA. US GEOL SURVEY,ALBANY,NY. RP FERNANDEZ, IJ (reprint author), UNIV MAINE,DEPT APPL ECOL & ENVIRONM SCI,ORONO,ME 04469, USA. NR 40 TC 16 Z9 16 U1 2 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD SEP PY 1995 VL 84 IS 1-2 BP 129 EP 145 DI 10.1007/BF00479593 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA RY463 UT WOS:A1995RY46300009 ER PT J AU GREEN, TR FREYBERG, DL AF GREEN, TR FREYBERG, DL TI STATE-DEPENDENT ANISOTROPY - COMPARISONS OF QUASI-ANALYTICAL SOLUTIONS WITH STOCHASTIC RESULTS FOR STEADY GRAVITY DRAINAGE SO WATER RESOURCES RESEARCH LA English DT Article ID UNSATURATED POROUS-MEDIA; HYDRAULIC CONDUCTIVITY; HETEROGENEOUS SOILS; SPATIAL VARIABILITY; FLOW; INFILTRATION; HILLSLOPE; SAND AB Anisotropy in large-scale unsaturated hydraulic conductivity of layered soils changes with the moisture state. Here, state-dependent anisotropy is computed under conditions of large-scale gravity drainage. Soils represented by Gardner's exponential function are perfectly stratified, periodic, and inclined. Analytical integration of Darcy's law across each layer results in a system of nonlinear equations that is solved iteratively for capillary suction at layer interfaces and for the Darcy flux normal to layering. Computed fluxes and suction profiles are used to determine both upscaled hydraulic conductivity in the principal directions and the corresponding ''state-dependent'' anisotropy ratio as functions of the mean suction. Three groups of layered soils are analyzed and compared with independent predictions from the stochastic results of Yeh et al. (1985b). The small-perturbation approach predicts appropriate behaviors for anisotropy under nonarid conditions. However, the stochastic results are limited to moderate values of mean suction; this limitation is linked to a Taylor series approximation in terms of a group of statistical and geometric parameters. Two alternative forms of the Taylor series provide upper and lower bounds for the state-dependent anisotropy of relatively dry soils. C1 STANFORD UNIV,DEPT CIVIL ENGN,STANFORD,CA 94305. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. RI Green, Timothy/E-1178-2011 NR 28 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD SEP PY 1995 VL 31 IS 9 BP 2201 EP 2211 DI 10.1029/95WR00790 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RT301 UT WOS:A1995RT30100007 ER PT J AU KRABBENHOFT, DP WEBSTER, KE AF KRABBENHOFT, DP WEBSTER, KE TI TRANSIENT HYDROGEOLOGICAL CONTROLS ON THE CHEMISTRY OF A SEEPAGE LAKE SO WATER RESOURCES RESEARCH LA English DT Article ID ESTIMATING GROUNDWATER EXCHANGE; ACIDIC LAKE; ALKALINITY REGULATION; FLORIDA; WISCONSIN; TRANSPORT; FLOW AB A solute mass balance method was used to estimate groundwater inflow and outflow rates for Nevins Lake, Michigan, a seepage lake in the upper peninsula that historically has shown extremely variable water chemistry compared with most other seepage lakes. A 4-year Study (1989-1992) of the hydrology and geochemistry of Nevins Lake and its contiguous groundwater system revealed that changes in the mass of dissolved solutes are the result of annual hydraulic gradient reversals. A pronounced acidification of Nevins Lake from 1986 to 1988 was likely caused by drought-induced diminished groundwater inflow rates. In this study, dissolved calcium (the major cation in water of Nevins Lake, groundwater, and precipitation) was used for estimating mass flow rates. During the 1989-1992 period, Nevins Lake showed a reproducible annual cycle in calcium mass. Immediately following spring snowmelt and the resulting hydraulic gradient reversal, the mass of dissolved calcium in the lake increases rapidly, and then it decreases steadily throughout the summer and early fall, at which time the lake becomes hydraulically mounded and receives no groundwater inflow. Groundwater flow rates estimated by the solute mass balance method are sensitive to assumed solute concentrations in discharging groundwater. Pore water samples from the lake bed are shown to be more representative of water discharging to the lake than are samples from piezometers near the lake shore, but spatial and temporal variability in pore water chemistry must be considered. Stable isotope analyses (O-18 and H-2) of lake water, groundwater, and pore water samples show that water discharging to Nevins Lake in the spring is entirely recycled lake water, and no groundwater derived from terrestrial recharge reaches the lake. The conceptual model formulated during this study linking lake chemistry and the contiguous groundwater system and general groundwater flow patterns surrounding highly transient lake systems are likely transferable to other similar systems. C1 WISCONSIN DEPT NAT RESOURCES,BUR RES,MONONA,WI 53716. RP KRABBENHOFT, DP (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,6417 NORMANDY LANE,MADISON,WI 53719, USA. OI Webster, Katherine/0000-0002-6009-0146 NR 26 TC 33 Z9 33 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD SEP PY 1995 VL 31 IS 9 BP 2295 EP 2305 DI 10.1029/95WR01582 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RT301 UT WOS:A1995RT30100015 ER PT J AU ARAVENA, R WASSENAAR, LI PLUMMER, LN AF ARAVENA, R WASSENAAR, LI PLUMMER, LN TI ESTIMATING C-14 GROUNDWATER AGES IN A METHANOGENIC AQUIFER SO WATER RESOURCES RESEARCH LA English DT Article ID DISSOLVED ORGANIC-CARBON; ISOTOPIC COMPOSITION; SOUTH-CAROLINA; METHANE; WATER; ONTARIO; SYSTEMS; CANADA; CO2; FERMENTATION AB This paper addresses the problem of C-14 age dating of groundwaters in a confined regional aquifer affected by methanogenesis. Increasing CH4 concentrations along the groundwater flow system and C-13 and C-14 isotopic data for dissolved inorganic carbon, dissolved organic carbon, and CH4 clearly show the effect of methanogenesis on groundwater chemistry. Inverse reaction path modeling using NETPATH indicates the predominant geochemical reactions controlling the chemical evolution of groundwater in the aquifer are incongruent dissolution of dolomite, ion exchange, methanogenesis, and oxidation of sedimentary organic matter. Modeling of groundwater C-14 ages using NETPATH indicates that a significant part of groundwater in the Alliston aquifer is less than 13,000 years old; however, older groundwater in the range of 15,000-23,000 years is also present in the aquifer. This paper demonstrates that C-14 ages calculated using NETPATH, incorporating the effects of methanogenesis on the carbon pools, provide reasonable groundwater ages that were not possible by other isotopic methods. C1 US GEOL SURVEY,432 NATL CTR,RESTON,VA 22092. ENVIRONM CANADA,NATL HYDROL RES INST,SASKATOON,SK S7N 3H5,CANADA. RP ARAVENA, R (reprint author), UNIV WATERLOO,WATERLOO CTR GROUNDWATER RES,WATERLOO,ON N2L 3G1,CANADA. RI Wassenaar, Leonard/B-5996-2013; OI Geyer, Stefan/0000-0003-1746-9019 NR 50 TC 52 Z9 53 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD SEP PY 1995 VL 31 IS 9 BP 2307 EP 2317 DI 10.1029/95WR01271 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RT301 UT WOS:A1995RT30100016 ER PT J AU BOHLKE, JK DENVER, JM AF BOHLKE, JK DENVER, JM TI COMBINED USE OF GROUNDWATER DATING, CHEMICAL, AND ISOTOPIC ANALYSES TO RESOLVE THE HISTORY AND FATE OF NITRATE CONTAMINATION IN 2 AGRICULTURAL WATERSHEDS, ATLANTIC COASTAL-PLAIN, MARYLAND SO WATER RESOURCES RESEARCH LA English DT Article ID CHLOROFLUOROCARBONS CCL3F; HYDROLOGIC TRACERS; DELMARVA PENINSULA; NITROGEN-ISOTOPE; SANDY AQUIFER; SURFACE-WATER; DENITRIFICATION; CO2; REDUCTION; WETLANDS AB The history and fate of groundwater nitrate (NO3-) contamination were compared in 2 small adjacent: agricultural watersheds in the Atlantic coastal plain by combined use of chronologic (CCl2F2,H-3), chemical (dissolved solids, gases), and isotopic (delta(15)N, delta(13)C, delta(34)S) analyses of recharging groundwaters, discharging groundwaters, and surface waters. The results demonstrate the interactive effects of changing agricultural practices, groundwater residence times, and local geologic features on the transfer of NO3- through local flow systems. Recharge dates of groundwaters taken in 1990-1992 from the surficial aquifer in the Chesterville Branch and Morgan Creek watersheds near Locust Grove, Maryland, ranged from pre-1940 to the late 1980's. When corrected for localized denitrification by use of dissolved gas concentrations, the dated waters provide a 40-year record of the recharge rate of NO3-, which increased in both watersheds by a factor of 3-6, most rapidly in the 1970's. The increase in groundwater NO3- over time was approximately proportional to the documented increase in regional N fertilizer use, and could be accounted for by oxidation and leaching of about 20-35% of the fertilizer N. Groundwaters discharging upward beneath streams in both watersheds had measured recharge dates from pre-1940 to 1975, while chemical data for second-order reaches of the streams indicated average groundwater residence times in the order of 20+ years. At the time of the study, NO3- discharge rates were less than NO3- recharge rates for at least two reasons: (1) discharge of relatively old waters with low initial NO3- concentrations, and (2) local denitrification. In the Chesterville Branch watershed, groundwaters remained oxic throughout much of the surficial aquifer and discharged relatively unaltered to the stream, which had a relatively high NO3- concentration (9-10 mg/L as N). In the Morgan Creek watershed, groundwaters were largely reduced and denitrified before discharging to the stream, which had a relatively low NO3- concentration (2-3 mg/L as N). Chemical and isotopic data indicate that quantitative denitrification occurred within buried calcareous glauconitic marine sediments that are present at relatively shallow depths beneath the Morgan Creek watershed. NO3- removal by forests, wetlands, and shallow organic-rich soils in near-stream environments was largely avoided by groundwaters that followed relatively deep flow paths before converging and discharging rapidly upward to the streams. C1 US GEOL SURVEY,DOVER,DE 19901. RP BOHLKE, JK (reprint author), US GEOL SURVEY,431 NATL CTR,RESTON,VA 22092, USA. NR 83 TC 370 Z9 378 U1 13 U2 107 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD SEP PY 1995 VL 31 IS 9 BP 2319 EP 2339 DI 10.1029/95WR01584 PG 21 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RT301 UT WOS:A1995RT30100017 ER PT J AU FREAD, DL SHEDD, RC SMITH, GF FARNSWORTH, R HOFFEDITZ, CN WENZEL, LA WIELE, SM SMITH, JA DAY, GN AF FREAD, DL SHEDD, RC SMITH, GF FARNSWORTH, R HOFFEDITZ, CN WENZEL, LA WIELE, SM SMITH, JA DAY, GN TI MODERNIZATION IN THE NATIONAL WEATHER SERVICE RIVER AND FLOOD PROGRAM SO WEATHER AND FORECASTING LA English DT Article AB Hydrologic forecasting is vital not only to the National Weather Service mission of saving lives and protecting property but also to our nation's water management decision makers. Since its inception, the River and Flood Program has continually endeavored to modernize its tools and techniques. Modernization is an innovative process of research and development that strives to make available the best methods, data, and equipment for hydrologic forecasts. This paper addresses the role of modern technology (e.g., automation, computers, and radar) in hydrologic forecasting and also examines some of the problems of river modeling and forecasting and what modernization tools are available to remedy them. In addition, this paper looks at the increasing importance of training personnel to effectively use these modernized methods, procedures, and equipment in their jobs. C1 NATL WEATHER SERV,OFF HYDROL,SILVER SPRING,MD 20910. US GEOL SURVEY,LAKEWOOD,CO 80225. PRINCETON UNIV,PRINCETON,NJ 08544. RIVERSIDE TECHNOL INC,COLUMBIA,MD. NR 9 TC 30 Z9 30 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1995 VL 10 IS 3 BP 477 EP 484 DI 10.1175/1520-0434(1995)010<0477:MITNWS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA RQ784 UT WOS:A1995RQ78400003 ER PT J AU WINTER, TC ROSENBERRY, DO AF WINTER, TC ROSENBERRY, DO TI THE INTERACTION OF GROUND-WATER WITH PRAIRIE POTHOLE WETLANDS IN THE COTTONWOOD LAKE AREA, EAST-CENTRAL NORTH-DAKOTA, 1979-1990 SO WETLANDS LA English DT Article DE HYDROLOGY; PRAIRIE POTHOLE; EVAPOTRANSPIRATION; SEEPAGE; GROUNDWATER MOVEMENT; CLIMATE; SOIL FROST AB The interaction of ground water with prairie wetlands in the Cottonwood Lake area has been the focus of research by the U.S. Geological Survey and the U.S. Fish and Wildlife Service since 1977. During this time, climatic conditions at the site ranged from near the driest to near the wettest of he century. Water levels in wetlands and in water-table wells throughout the study area responded to these changing climate conditions in a variety of ways. The topographically highest wetlands recharged ground water whenever they received water from precipitation. The wetland of principal interest, Wetland P1, which is at an intermediate altitude, received ground-water discharge much of the time, but it also had transpiration-induced seepage from it along parts of its perimeter during all bur the wettest year. The large;fluctuations of the water table in response to recharge and transpiration reflect the ease with which water moves vertically through the fractured till. Lateral movement of ground water is much slower; pore-water velocities are generally less than 3 m yr(-1). The water supply to the wetlands is largely from precipitation during fall, winter, and spring. During these periods, precipitation either falls directly on the wetland, or precipitation that falls on the upland runs over frozen soils or saturated soils into the wetland. The average ratio of stage rise to total overwinter precipitation was 2.59 for the 12-year study period. After plants leaf out, precipitation generally results in much lower rises of the wetland water level. The average ratio of stage rise to over-summer precipitation was less than 1.0. RP WINTER, TC (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 413,LAKEWOOD,CO 80225, USA. RI Rosenberry, Donald/C-2241-2013; OI Rosenberry, Donald/0000-0003-0681-5641 NR 0 TC 105 Z9 106 U1 1 U2 14 PU SOC WETLAND SCIENTISTS PI LAWRENCE PA 810 E TENTH ST, P O BOX 1897, LAWRENCE, KS 66044 SN 0277-5212 J9 WETLANDS JI Wetlands PD SEP PY 1995 VL 15 IS 3 BP 193 EP 211 PG 19 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA RX938 UT WOS:A1995RX93800001 ER PT J AU WILLIAMS, BK JOHNSON, FA AF WILLIAMS, BK JOHNSON, FA TI ADAPTIVE MANAGEMENT AND THE REGULATION OF WATERFOWL HARVESTS SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE ADAPTIVE MANAGEMENT; DECISION; HARVEST; HUNTING; UNCERTAINTY; WATERFOWL C1 UNIV VERMONT,COOPERAT FISH & WILDLIFE RES UNIT,BURLINGTON,VT 05405. US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,LAUREL,MD 20708. NR 19 TC 95 Z9 98 U1 1 U2 22 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD FAL PY 1995 VL 23 IS 3 BP 430 EP 436 PG 7 WC Biodiversity Conservation SC Biodiversity & Conservation GA RR480 UT WOS:A1995RR48000020 ER PT J AU HAUKOS, DA SMITH, LM AF HAUKOS, DA SMITH, LM TI CHEMICAL-COMPOSITION OF SEEDS FROM PLANTS IN PLAYA WETLANDS SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE CARBOHYDRATES; DETERGENT ANALYSIS; FAT; FIBER; MOIST-SOIL MANAGEMENT; PLAYAS; PROTEIN; PROXIMATE ANALYSIS; SEEDS; WATERFOWL ID NORTHERN PINTAILS; LAKES AB We evaluated effects of moist-soil management on chemical constituents of seeds from 5 moist-soil plant species. We measured ash, total nonstructural carbohydrates (TNC), crude protein, crude fat, hemicellulose, cellulose, lignin, and cutin-suberin. There were no differences between moist-soil managed and unmanaged playas. Chemical constituents differed among species, with seeds from barnyardgrass (Echinochloa crusgalli) and smartweeds (Persicaria spp.) the preferred species for management. Large-scale environmental conditions may determine chemical composition of seeds from moist-soil plants in playas. Future chemical analyses of seeds from wetland plants should concentrate on isolation of specific constituents to provide a complete analysis of forage. RP HAUKOS, DA (reprint author), TEXAS TECH UNIV,DEPT RANGE & WILDLIFE MANAGEMENT,US FISH & WILDLIFE SERV,LUBBOCK,TX 79409, USA. NR 23 TC 12 Z9 12 U1 0 U2 1 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD FAL PY 1995 VL 23 IS 3 BP 514 EP 519 PG 6 WC Biodiversity Conservation SC Biodiversity & Conservation GA RR480 UT WOS:A1995RR48000033 ER PT J AU KILBRIDE, KM PAVEGLIO, FL GRUE, CE AF KILBRIDE, KM PAVEGLIO, FL GRUE, CE TI CONTROL OF SMOOTH CORDGRASS WITH RODEO(R) IN A SOUTHWESTERN WASHINGTON ESTUARY SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE ESTUARY; GLYPHOSATE; MUDFLATS; NONYLPHENOL POLYETHOXYLATES; RODEO(R); SMOOTH CORDGRASS; SPARTINA ALTERNIFLORA; SURFACTANT ID GLYPHOSATE; METABOLISM; FATE AB We investigated efficacy of aerial and ground application of Rodeo(R) to control smooth cordgrass (Spartina alterniflora) on intertidal mudflats in Willapa Bay, Washington during 1992-1993. The herbicidal formula was applied to 2 1-ha plots using a helicopter with toe-mounted spray boom or by hand-held wand sprayer. Stem densities did not differ from pre- to post-treatment between aerially treated and control clones, Stem densities were reduced on clones where the herbicidal formulation was applied by hand, Stem density was reduced most at plots located highest in the intertidal zone, Efficacy depended on the time between treatment and subsequent tidal inundation of treated plants. C1 UNIV WASHINGTON,SCH FISHERIES WH-10,WASHINGTON COOPERAT FISH & WILDLIFE RES UNIT,NATL BIOL SERV,SEATTLE,WA 98195. RP KILBRIDE, KM (reprint author), US FISH & WILDLIFE SERV,9317 NE HIGHWAY 99,SUITE D,VANCOUVER,WA 98665, USA. NR 18 TC 11 Z9 13 U1 0 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD FAL PY 1995 VL 23 IS 3 BP 520 EP 524 PG 5 WC Biodiversity Conservation SC Biodiversity & Conservation GA RR480 UT WOS:A1995RR48000034 ER PT J AU MAYER, PM LICHT, DS AF MAYER, PM LICHT, DS TI PERSISTENCE AND USE OF ARTIFICIAL PRAIRIE FALCON AERIES IN NORTH-DAKOTA SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE AERIE; ARTIFICIAL NEST; FALCO MEXICANUS; NORTH DAKOTA; PRAIRIE FALCON C1 US FISH & WILDLIFE SERV,BISMARCK,ND 58501. NR 10 TC 0 Z9 0 U1 0 U2 0 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD FAL PY 1995 VL 23 IS 3 BP 532 EP 534 PG 3 WC Biodiversity Conservation SC Biodiversity & Conservation GA RR480 UT WOS:A1995RR48000036 ER PT J AU GEISSLER, P THOMPSON, WR GREENBERG, R MOERSCH, J MCEWEN, A SAGAN, C AF GEISSLER, P THOMPSON, WR GREENBERG, R MOERSCH, J MCEWEN, A SAGAN, C TI GALILEO MULTISPECTRAL IMAGING OF EARTH SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THEMATIC MAPPER; SNOW; COVER AB Nearly 6000 multispectral images of Earth were acquired by the Galileo spacecraft during its two flybys. The Galileo images offer a unique perspective on our home planet through the spectral capability made possible by four narrowband near-infrared filters, intended for observations of methane in Jupiter's atmosphere, which are not incorporated in any of the currently operating Earth orbital remote sensing systems. Spectral variations due to mineralogy, vegetative cover, and condensed water are effectively mapped by the visible and near-infrared multispectral imagery, showing a wide variety of biological, meteorological, and geological phenomena. Global tectonic and volcanic processes are clearly illustrated by these images, providing a useful basis for comparative planetary geology. Differences between plant species are detected through the narrowband IR filters on Galileo, allowing regional measurements of variation in the ''red edge'' of chlorophyll and the depth of the 1-mu m water band, which is diagnostic of leaf moisture content. Although evidence of life is widespread in the Galileo data set, only a single image (at similar to 2 km/pixel) shows geometrization plausibly attributable to our technical civilization Water vapor can be uniquely imaged in the Galileo 0.73-mu m band, permitting spectral discrimination of moist and dry clouds with otherwise similar albedo. Surface snow and ice can be readily distinguished from cloud cover by narrowband imaging within the sensitivity range of Galileo's silicon CCD camera. Ice grain size variations can be mapped using the weak H2O absorption at 1 mu m, a technique which may find important applications in the exploration of the moons of Jupiter. The Galileo images have the potential to make unique contributions to Earth science in the areas of geological, meteorological and biological remote sensing, due to the inclusion of previously untried narrowband IR filters. The vast scale and near global coverage of the Galileo data set complements the higher-resolution data from Earth orbiting systems and may provide a valuable reference point for future studies of global change. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. CORNELL UNIV,PLANETARY STUDIES LAB,ITHACA,NY 14853. RP GEISSLER, P (reprint author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA. RI Moersch, Jeffrey/F-7189-2010 NR 29 TC 10 Z9 10 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 1995 VL 100 IS E8 BP 16895 EP 16906 DI 10.1029/95JE01407 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT914 UT WOS:A1995RT91400003 PM 11539416 ER PT J AU FARRAR, CD SOREY, ML EVANS, WC HOWLE, JF KERR, BD KENNEDY, BM KING, CY SOUTHON, JR AF FARRAR, CD SOREY, ML EVANS, WC HOWLE, JF KERR, BD KENNEDY, BM KING, CY SOUTHON, JR TI FOREST-KILLING DIFFUSE CO2 EMISSION AT MAMMOTH MOUNTAIN AS A SIGN OF MAGMATIC UNREST SO NATURE LA English DT Article ID LONG VALLEY CALDERA; CARBON-DIOXIDE; CALIFORNIA; ERUPTIONS; VOLCANO; SOIL AB MAMMOTH Mountain, in the western United States, is a large dacitic volcano with a long history of volcanism that began 200 kyr ago(1) and produced phreatic eruptions as recently as 500+/- 200 yr sp (ref. 2). Seismicity, ground deformation and changes in fumarole gas composition suggested an episode of shallow dyke intrusion in 1989-90 (refs 3, 4), Areas of dying forest and incidents of near asphyxia in confined spaces, first reported in 1990, prompted us to search for diffuse flank emissions of magmatic CO2, as have been described at Mount Etna(5) and Vulcano(6). Here we report the results of a soil-gas survey, begun in 1994, that revealed CO2 concentrations of 30-96% in a 30-hectare region of killed trees, from which we estimate a total CO2 flux of greater than or equal to 1,200 tonnes per day, The forest die-off is the most conspicuous surface manifestation of magmatic processes at Mammoth Mountain, which hosts only weak fumarolic vents and no summit activity, Although the onset of tree kill coincided with the episode of shallow dyke intrusion, the magnitude and duration of the CO2 flux indicates that a larger, deeper magma source and/or a large reservoir of high-pressure gas is being tapped. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,SACRAMENTO,CA 95825. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP FARRAR, CD (reprint author), US GEOL SURVEY,CARNELIAN BAY,CA 96140, USA. RI Evans, William/J-4283-2012 NR 23 TC 194 Z9 198 U1 2 U2 12 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD AUG 24 PY 1995 VL 376 IS 6542 BP 675 EP 678 DI 10.1038/376675a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RQ672 UT WOS:A1995RQ67200056 ER PT J AU MILLS, MS THURMAN, EM AF MILLS, MS THURMAN, EM TI CHEMISTRY AND SOURCES OF NATURAL AQUATIC FOAM SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DIV WATER RESOURCES,LAWRENCE,KS 66049. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 15 EP IEC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601980 ER PT J AU BELKIN, HE AF BELKIN, HE TI PT-GROUP ELEMENT (PGE) PARAGENESIS IN MESOZOIC INTRUSIVE ROCKS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 25 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601872 ER PT J AU BEIHOFFER, J BOUR, E GIBSON, GP LOWRY, JH RESCHL, JJ SEIDEL, GL AF BEIHOFFER, J BOUR, E GIBSON, GP LOWRY, JH RESCHL, JJ SEIDEL, GL TI IDENTIFICATION AND DETERMINATION OF THE ISOMERIC BROMO AND/OR CHLOROSUBSTITUTED 1,3-DIHALO-5,5-DIMETHYLHYDANTOINS USED IN DISINFECTANTS AND PESTICIDES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 DENVER FED CTR,EPA,NEIC,DENVER,CO 80225. UNIV WISCONSIN,DEPT CHEM,OSHKOSH,WI 54901. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 26 EP ANYL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25600374 ER PT J AU THORN, KA GOLDENBERG, WS YOUNGER, SJ AF THORN, KA GOLDENBERG, WS YOUNGER, SJ TI COVALENT BINDING OF ANILINE TO HUMIC SUBSTANCES AND WHOLE SOIL ORGANIC-MATTER SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,ARVADA,CO 80002. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 35 EP IEC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601999 ER PT J AU PALMER, CA FINKELMAN, RB KRASNOW, MR EBLE, CF AF PALMER, CA FINKELMAN, RB KRASNOW, MR EBLE, CF TI LABORATORY LEACHING OF ENVIRONMENTALLY SENSITIVE TRACE-ELEMENTS FROM FLY-ASH AND BOTTOM ASH SAMPLES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. KENTUCKY GEOL SURVEY,LEXINGTON,KY 40506. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 75 EP FUEL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601776 ER PT J AU KILE, DE CHIOU, CT WERSHAW, RL ZHOU, H AF KILE, DE CHIOU, CT WERSHAW, RL ZHOU, H TI DIFFERENCES IN ORGANIC-MATTER POLARITIES BETWEEN SOILS AND SEDIMENTS AS MEASURED BY NONPOLAR SOLUTE PARTITION-COEFFICIENTS AND SOLID-STATE C-13 NMR SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 MINIST WATER RESOURCES,BEIJING 100044,PEOPLES R CHINA. US GEOL SURVEY,LAKEWOOD,CO 80225. RI Chiou, Cary/C-3203-2013 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 77 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601506 ER PT J AU MAJEWSKI, MS WOODROW, JE SEIBER, JN AF MAJEWSKI, MS WOODROW, JE SEIBER, JN TI METHYL-BROMIDE VOLATILITY MEASUREMENTS FROM TREATED FIELDS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,SACRAMENTO,CA 95825. UNIV CALIF DAVIS,DEPT ENVIRONM TOXICOL,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 90 EP AGRO PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25600330 ER PT J AU HURLEY, JP COWELL, SE BENOIT, JM SHAFER, MM HUGHES, PE AF HURLEY, JP COWELL, SE BENOIT, JM SHAFER, MM HUGHES, PE TI TOTAL AND METHYL MERCURY IN SELECTED GREAT-LAKES TRIBUTARIES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 WISCONSIN DEPT NAT RESOURCES,BUR RES,MONONA,WI 53176. UNIV WISCONSIN,WATER CHEM PROG,MADISON,WI 53706. US GEOL SURVEY,MADISON,WI 53719. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 94 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25601937 ER PT J AU CREPEAU, KL KUIVILA, KM DOMAGALSKI, JL AF CREPEAU, KL KUIVILA, KM DOMAGALSKI, JL TI DISSOLVED RICE PESTICIDE CONCENTRATIONS IN THE COLUSA BASIN DRAIN AND SACRAMENTO RIVER, CALIFORNIA, 1990-93 SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,SACRAMENTO,CA 95825. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 1995 VL 210 BP 108 EP AGRO PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA RP256 UT WOS:A1995RP25600348 ER PT J AU HOLROYD, PA CIOCHON, RL AF HOLROYD, PA CIOCHON, RL TI NEW ARTIODACTYL (MAMMALIA) FROM THE EOCENE PONDAUNG SANDSTONES, BURMA SO ANNALS OF CARNEGIE MUSEUM LA English DT Article AB Reanalysis of artiodactyl material from the late middle Eocene Pondaung sandstones of Burma indicates the presence of a new genus assignable to the Helohyidae. A single specimen, previously described as an anthracotheriid and placed in the genus Anthracokeryx, is described below as Pakkokuhyus, n. gen. Pakkokuhyus, n. gen., represents the most southerly occurrence of the family Helohyidae. The new Burmese genus also has resemblances to the putative raoellid Haqueina from the early or middle Eocene of Pakistan. C1 US GEOL SURVEY,DENVER,CO 80225. UNIV IOWA,DEPT ANTHROPOL,IOWA CITY,IA 52242. UNIV IOWA,DEPT PEDIAT DENT,IOWA CITY,IA 52242. NR 20 TC 10 Z9 11 U1 0 U2 0 PU CARNEGIE MUSEUM NATURAL HISTORY PI PITTSBURGH PA 4400 FORBES AVE, PITTSBURGH, PA 15213 SN 0097-4463 J9 ANN CARNEGIE MUS JI Ann. Carnegie Mus. PD AUG 18 PY 1995 VL 64 IS 3 BP 177 EP 183 PG 7 WC Paleontology; Zoology SC Paleontology; Zoology GA RT206 UT WOS:A1995RT20600001 ER PT J AU HON, K PALLISTER, J AF HON, K PALLISTER, J TI VOLCANISM - WRESTLING WITH RESTLESS CALDERAS AND FIGHTING FLOODS OF LAVA SO NATURE LA English DT Editorial Material RP HON, K (reprint author), US GEOL SURVEY,DENVER FED CTR,MS903,LAKEWOOD,CO 80225, USA. OI Pallister, John/0000-0002-2041-2147 NR 0 TC 2 Z9 2 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD AUG 17 PY 1995 VL 376 IS 6541 BP 554 EP 555 DI 10.1038/376554a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RP756 UT WOS:A1995RP75600028 ER PT J AU KOMOR, SC AF KOMOR, SC TI CHEMISTRY AND PETROGRAPHY OF CALCITE IN THE KTB PILOT BOREHOLE, BAVARIAN OBERPFALZ, GERMANY SO CHEMICAL GEOLOGY LA English DT Article ID BOHEMIAN MASSIF; ISOTOPE GEOCHEMISTRY; ROCKS; CONSTRAINTS; EVOLUTION; GRAPHITE; DEPOSITS; ORIGIN; HOLE AB The KTB (Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland) pilot borehole in northeast Bavaria, Germany, penetrates 4000 m of gneiss, amphibolite, and subordinate calc-silicate, lamprophyre and metagabbro. There are three types of calcite in the drilled section: (1) metamorphic calcite in calc-silicate and marble; (2) crack-filling calcite in all lithologies; and (3) replacement calcite in altered minerals. Crack-filling and replacement calcite postdate metamorphic calcite. Multiple calcite generations in individual cracks suggest that different generations of water repeatedly flowed through the same cracks. Cracks that eventually filled with calcite carried water to sites where replacement calcite formed by plagioclase hydrolysis or other decarbonation reactions. Whole-rock contents of all three calcite types range from similar to 35 wt% in near-surface calc-silicate to <0.1 wt% in amphibolite with calcite-filled cracks at 3872 m. Calcite contains average Sr concentrations of 180 ppm and Mn concentrations of 3980 ppm. Crack-filling calcite microdrilled from thin sections has average delta(13)C = -9.0 +/- 2.2 parts per thousand and delta(18)O = +10.5 +/- 1.5 parts per thousand (+/- values are 1 standard deviation). Crack-filling mineral assemblages that include calcite originally formed at temperatures of 150-350 degrees C. Presently, crack-filling calcite is in chemical and isotopic equilibrium with saline to brackish water in the borehole at temperatures of less than or equal to 120 degrees C. The saline to brackish water contains a significant proportion of meteoric water. Re-equilibration of crack-filling calcite to lower temperatures means that calcite chemistry tells us little about water-rock interactions in the crustal section at temperatures higher than similar to 120 degrees C. RP KOMOR, SC (reprint author), US GEOL SURVEY,2280 WOODALE DR,MOUNDS VIEW,MN 55112, USA. NR 33 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD AUG 15 PY 1995 VL 124 IS 3-4 BP 199 EP 215 DI 10.1016/0009-2541(95)00063-R PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT462 UT WOS:A1995RT46200003 ER PT J AU KESZTHELYI, L AF KESZTHELYI, L TI MEASUREMENTS OF THE COOLING AT THE BASE OF PAHOEHOE FLOWS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CRYSTAL-GROWTH; LAVA FLOWS; CRYSTALLIZATION; NUCLEATION; MODEL AB Temperature measurements were made in August and October of 1994 at the base of small active pahoehoe flow lobes on Kilauea Volcano, Hawai'i. Surprisingly, after about 2 minutes of initial rapid cooling, the basal temperatures increased significantly before resuming a slower cooling trend The recorded temperatures are also warmer than those predicted by simple conductive cooling models. Preliminary calculations suggest that these observations can be explained by the insulating effect of microfractures in the underlying flow and the kinetics of crystallization. The initial cooling may be rapid enough to supercool the lava such that the onset of crystallization is delayed. When crystallization does begin, it is initially rapid, releasing sufficient latent heat to re-heat the lava. As the system equilibrates, the now resumes a slow cooling. C1 US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HI 96718. NR 10 TC 30 Z9 30 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1995 VL 22 IS 16 BP 2195 EP 2198 DI 10.1029/95GL01812 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RT333 UT WOS:A1995RT33300030 ER PT J AU TAKAUCHI, Y EVANS, JR AF TAKAUCHI, Y EVANS, JR TI TELESEISMIC TOMOGRAPHY OF THE LOMA-PRIETA EARTHQUAKE REGION, CALIFORNIA - IMPLICATIONS FOR STRAIN PARTITIONING SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VELOCITY; EVOLUTION; IMAGES; SYSTEM AB From teleseismic travel times we derive three-dimensional velocity models of the upper 71 km in the 1989 Loma Prieta earthquake region, central California. Shallow crustal structure is consistent with local-earthquake tomography. Horizontal velocity gradients at all depths suggest that the San Andreas fault was a deep shear locus, at least at one time. A large low-velocity feature near the Moho beneath Loma Prieta probably is caused by a crustal root. Two low-velocity features at about 45-70 km depth are offset right-laterally along the San Andreas by about 45 km. Cooling of this portion of the upper mantle [Furlong et at, 1989] could have frozen in displacements in this region within a few million years after passage of the Mendocino Triple Junction. These results are consistent with Furlong et al.'s model. RP TAKAUCHI, Y (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS-977,MENLO PK,CA 94025, USA. NR 17 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1995 VL 22 IS 16 BP 2203 EP 2206 DI 10.1029/95GL01601 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RT333 UT WOS:A1995RT33300032 ER PT J AU KIRBY, SH OKAL, EA ENGDAHL, ER AF KIRBY, SH OKAL, EA ENGDAHL, ER TI THE 9 JUNE 94 BOLIVIAN DEEP EARTHQUAKE - AN EXCEPTIONAL EVENT IN AN EXTRAORDINARY SUBDUCTION ZONE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LITHOSPHERE; SEISMICITY AB We investigate the physical setting of the Bolivian shock based on the history of the subducting Nazca plate, intraslab seismicity, deep seismic moment release, and seismic tomography. South America has two broad regions of reverse are curvature. Subduction constrained to this unique geometry produces slab kinking contortions that may cause unusual slab thickening as they sink to the bottom of the transition zone and encounter resistance to penetration into the lower mantle. Such contortions are observed at intermediate depths ''upstream'' from the slab source regions of both the great 1970 Colombian and 1994 Bolivian events. Thickening helps explain how the Nazca slab accommodates large seismic source dimensions at depths of 625-650 km. C1 US GEOL SURVEY,DENVER,CO 80225. NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60208. RP KIRBY, SH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 19 TC 33 Z9 33 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1995 VL 22 IS 16 BP 2233 EP 2236 DI 10.1029/95GL01802 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RT333 UT WOS:A1995RT33300040 ER PT J AU ENGDAHL, ER VANDERHILST, RD BERROCAL, J AF ENGDAHL, ER VANDERHILST, RD BERROCAL, J TI IMAGING OF SUBDUCTED LITHOSPHERE BENEATH SOUTH-AMERICA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NAZCA PLATE; PERU AB Tomographic images are produced for the deep structure of the Andean subduction zone beneath western South America The data used in the imaging are the delay times of P, pP and pwP phases from relocated teleseismic earthquakes in the region. Regionally, structural features larger than about 150 km are resolved by the data. Presentations of layer anomaly maps and cross sections reveal: (1) The Nazca slab is probably continuous laterally and at depth over most legions; (2) The offset between the north and south deep earthquake zones, containing the 1994 deep Bolivia main shock and its aftershocks, can be modelled by a northwest striking and steeply northeast dipping slab structure; and (3) The Nazca slab clearly penetrates the lower mantle beneath central South America, but is partly deflected in the southern deep zone. C1 AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT,AUSTRALIA. UNIV SAO PAULO,INST GEOPHYS,SAO PAULO,BRAZIL. RP ENGDAHL, ER (reprint author), US GEOL SURVEY,NATL EARTHQUAKE INFORMAT CTR,DENVER,CO 80225, USA. NR 12 TC 59 Z9 61 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1995 VL 22 IS 16 BP 2317 EP 2320 DI 10.1029/95GL02013 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RT333 UT WOS:A1995RT33300061 ER PT J AU CREAGER, KC CHIAO, LY WINCHESTER, JP ENGDAHL, ER AF CREAGER, KC CHIAO, LY WINCHESTER, JP ENGDAHL, ER TI MEMBRANE STRAIN RATES IN THE SUBDUCTING PLATE BENEATH SOUTH-AMERICA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WADATI-BENIOFF ZONES; NAZCA PLATE; LITHOSPHERE; GEOMETRY; PERU; SEISMICITY AB Geometric constraints associated with the concave oceanward bend in the trench and Andes Mountains, known as the Bolivian Orocline, force along-strike compression in the subducting slab. Our calculations of membrane strain rates, in an assumed continuous slab, demonstrate that this can be accommodated by either 10% along-strike compressive strain, or by geometric buckling. In nearly all other subduction zones exhibiting a similar bend in the trench, the compression is accommodated by slab-arching landward of the trench bend. The slab geometry is markedly different in South America. Two regions of nearly flat-lying slab north and south of the Bolivian Orocline result in the 150-km slab depth contour being much straighter than the trench profile. Our calculations show that this geometry helps to relieve along-strike compression. Along the deeper part of the subduction zone, the along-strike compression seems to be accommodated by pronounced along-strike buckling. We infer the approximate geometry of this buckle, in an otherwise aseismic region, from the great Mw 8.3 Bolivian deep earthquake on June 9, 1994, and its aftershocks. The deep slab appears to have a nearly east-west strike in the vicinity of this earthquake, whereas the strike is more nearly north-south to the north and south. The focal mechanisms of deep earthquakes exhibit consistent down-dip compression and along-strike null axes, tracking the contortions in slab geometry, However, our calculations indicate that the particle paths themselves are not down dip everywhere. Instead, where the deep-slab strike is oriented nearly east-west, the particle flow is more nearly along strike than down dip. In general this is not a major problem, but if the slab is anchored in the lower mantle, and moving very slowly, this produces large deformation rates near the base of the upper mantle where the slab is assumed to move at near plate rates. This increased, complex deformation in the deep slab may contribute to the conditions for very large earthquakes in two ways, First, this may dramatically increase deformation rates, and secondly, the increased deformation may lead to anomalous advective thickening of a proposed overdriven olivine wedge. This provides a mechanism for locally thickening the olivine wedge and allowing transformational faulting to occur over a much larger volume than allowed for normal subduction. C1 NATL TAIWAN UNIV,INST OCEANOG,TAIPEI,TAIWAN. US GEOL SURVEY,DENVER FED CTR,NEIC,DENVER,CO 80225. RP CREAGER, KC (reprint author), UNIV WASHINGTON,GEOPHYS PROGRAM,SEATTLE,WA 98195, USA. NR 25 TC 26 Z9 26 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1995 VL 22 IS 16 BP 2321 EP 2324 DI 10.1029/95GL02321 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RT333 UT WOS:A1995RT33300062 ER PT J AU WALKER, RJ MORGAN, JW HORAN, MF AF WALKER, RJ MORGAN, JW HORAN, MF TI OS-187 ENRICHMENT IN SOME PLUMES - EVIDENCE FOR CORE-MANTLE INTERACTION SO SCIENCE LA English DT Article ID IRON-METEORITES; OCEANIC BASALTS; ISOTOPE SYSTEMATICS; ISLAND BASALTS; EARTHS CORE; ELEMENTS; SIDEROPHILE; ABUNDANCES; EVOLUTION; GROWTH AB Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the chondritic upper mantle, potentially leading to an outer core with an osmium-187/osmium-188 ratio at least 8 percent greater than that of chondrites. Because of the much greater abundance of osmium in the outer core relative to the mantle, even a small addition of metal to a plume ascending from the D '' layer would transfer the enriched isotopic signature to the mixture. Sources of certain plume-derived systems seem to have osmium-187/osmium-188 ratios 5 to 20 percent greater than that for chondrites, consistent with the ascent of a plume from the core-mantle boundary. C1 US GEOL SURVEY,RESTON,VA 22092. RP WALKER, RJ (reprint author), UNIV MARYLAND,DEPT GEOL,ISOTOPE GEOL LAB,COLLEGE PK,MD 20742, USA. RI Walker, Richard/K-6869-2016 OI Walker, Richard/0000-0003-0348-2407 NR 42 TC 153 Z9 161 U1 3 U2 19 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 11 PY 1995 VL 269 IS 5225 BP 819 EP 822 DI 10.1126/science.269.5225.819 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RN650 UT WOS:A1995RN65000039 PM 17778741 ER PT J AU BASU, AR POREDA, RJ RENNE, PR TEICHMANN, F VASILIEV, YR SOBOLEV, NV TURRIN, BD AF BASU, AR POREDA, RJ RENNE, PR TEICHMANN, F VASILIEV, YR SOBOLEV, NV TURRIN, BD TI HIGH-HE-3 PLUME ORIGIN AND TEMPORAL-SPATIAL EVOLUTION OF THE SIBERIAN FLOOD BASALTS SO SCIENCE LA English DT Article ID CONVECTION PLUMES; TRIASSIC BOUNDARY; RAPID ERUPTION; MANTLE PLUMES; TRACE-ELEMENT; PB; CONSTRAINTS; VOLCANISM; ISOTOPES; TRAPS AB An olivine nephelinite from the lower part of a thick alkalic ultrabasic and mafic sequence of volcanic rocks of the northeastern part of the Siberian flood basalt province (SFBP) yielded a Ar-40/Ar-39 plateau age of 253.3 +/- 2.6 million years, distinctly older than the main tholeiitic pulse of the SFBP at 250.0 million years. Olivine phenocrysts of this rock showed He-3/He-4 ratios up to 12.7 times the atmospheric ratio; these values suggest a lower mantle plume origin. The neodymium and strontium isotopes, rare earth element concentration patterns, and cerium/lead ratios of the associated rocks were also consistent with their derivation from a near-chondritic, primitive plume. Geochemical data from the 250-million-year-old volcanic rocks higher up in the sequence indicate interaction of this high-He-3 SFBP plume with a suboceanic-type upper mantle beneath Siberia. C1 BERKLEY GEOCHRONOL CTR,BERKELEY,CA 94709. RUSSIAN ACAD SCI,INST MINERAL & PETROL,NOVOSIBIRSK 630090,RUSSIA. US GEOL SURVEY,MENLO PK,CA 94025. RP BASU, AR (reprint author), UNIV ROCHESTER,DEPT EARTH & ENVIRONM SCI,ROCHESTER,NY 14627, USA. RI Sobolev, Nikolay/A-3850-2014; Vasiliev, Yurii/A-5374-2014 NR 35 TC 130 Z9 150 U1 1 U2 15 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 11 PY 1995 VL 269 IS 5225 BP 822 EP 825 DI 10.1126/science.269.5225.822 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RN650 UT WOS:A1995RN65000040 PM 17778742 ER PT J AU CRAYMER, MR VANICEK, P CASTLE, RO AF CRAYMER, MR VANICEK, P CASTLE, RO TI ESTIMATION OF ROD SCALE ERRORS IN GEODETIC LEVELING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SOUTHERN-CALIFORNIA; REFRACTION ERROR; SAUGUS-PALMDALE; FIELD-TEST; UPLIFT AB Comparisons among repeated geodetic levelings have often been used for detecting and estimating residual rod scale errors in leveled heights. Individual rod-pair scale errors are estimated by a two-step procedure using a model based on either differences in heights, differences in section height differences, or differences in section tilts. It is shown that the estimated rod-pair scale errors derived from each model are identical only when the data are correctly weighted, and the mathematical correlations are accounted for in the model based on heights. Analyses based on simple regressions of changes in height versus height can easily lead to incorrect conclusions. We also show that the statistically estimated scale errors are not a simple function of height, height difference, or tilt. The models are valid only when terrain slope is constant over adjacent pairs of setups (i.e., smoothly varying terrain). In order to discriminate between rod scale errors and vertical displacements due to crustal motion, the individual rod-pairs should be used in more than one leveling, preferably in areas of contrasting tectonic activity. From an analysis of 37 separately calibrated rod-pairs used in 55 levelings in southern California, we found eight statistically significant coefficients that could be reasonably attributed to rod scale errors, only one of which was larger than the expected random error in the applied calibration-based scale correction. However, significant differences with other independent checks indicate that caution should be exercised before accepting these results as evidence of scale error. Further refinements of the technique are clearly needed if the results are to be routinely applied in practice. C1 UNIV NEW BRUNSWICK, DEPT SURVEYING ENGN, FREDERICTON, NB E3B 5A3, CANADA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP CRAYMER, MR (reprint author), GEOMAT CANADA, DIV GEODET SURVEY, 615 BOOTH ST, OTTAWA, ON K1A 0E9, CANADA. NR 23 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD AUG 10 PY 1995 VL 100 IS B8 BP 15129 EP 15145 DI 10.1029/95JB00614 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RN992 UT WOS:A1995RN99200012 ER PT J AU MILLER, KC MOONEY, WD AF MILLER, KC MOONEY, WD TI CRUSTAL STRUCTURE AND COMPOSITION OF THE SOUTHERN FOOTHILLS METAMORPHIC BELT, SIERRA-NEVADA, CALIFORNIA, FROM SEISMIC DATA - REPLY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ORIENTATION C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP MILLER, KC (reprint author), UNIV TEXAS, DEPT GEOL SCI, EL PASO, TX 79968 USA. RI Miller, Kate/E-6800-2012 NR 7 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD AUG 10 PY 1995 VL 100 IS B8 BP 15405 EP 15405 DI 10.1029/95JB01050 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RN992 UT WOS:A1995RN99200031 ER PT J AU KELLEY, JS BROSGE, WP AF KELLEY, JS BROSGE, WP TI GEOLOGIC FRAMEWORK OF A TRANSECT OF THE CENTRAL BROOKS RANGE - REGIONAL RELATIONS AND AN ALTERNATIVE TO THE ENDICOTT MOUNTAINS ALLOCHTHON SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID ALASKA AB This paper evaluates the geologic framework and tectonic development of the central Brooks Range based on a transect through the range and Arctic foothills, A geologic cross section constructed through the transect is confirmed by comparing the retrodeformed section with the regional distribution of lithofacies in the central Brooks Range, Stratigraphic relations in the retrodeformed section are further explained by comparing them to similar stratigraphic relations in the Ikpikpuk-Umiat basin under the Arctic coastal plain. The structural framework of the central Brooks Range and Arctic foothills consists of fold nappes, thrust faults, and detached folds that sole in decollements and late-stage high-angle faults. In the central Brooks Range, shortening is by north-directed thrust faulting and folding of mostly Paleozoic rocks, and transport of any individual thrust sheet relative to underlying rocks is less than 30 km. In the middle of the range, imbricate blocks of lower Paleozoic basement are exposed in the core of the Doonerak anticline, and thrust sheets of stratigraphically higher Paleozoic rocks that overlie basement are exposed in the limbs of the anticline. In the northeast part of the anticline, the Amawk thrust emplaces Silurian and Upper Devonian rocks on a succession of Lower Mississippian and stratigraphically higher rocks that have been detached from the underlying basement along the Blarney Creek thrust. The Slatepile fault system, a system of high-angle faults in the north limb of the Doonerak anticline, drops the core and part of the north limb of the anticline down, giving the impression that the succession of Lower Mississippian and stratigraphically higher rocks that lie on basement south of the system high-angle faults extends under the Upper Devonian rocks that extensively crop out north of the high-angle faults, In the Arctic foothills, the mostly Paleozoic rocks of the northcentral Brooks Range extend under Lower Cretaceous rocks of the North Slope foreland basin, and blind thrusts that sole in the Paleozoic rocks ramp up into the Lower Cretaceous and stratigraphically higher rocks, Also in the Arctic foothills, a thrust sheet that contains the Arctic foothills assemblage overlies rocks of the north-central Brooks Range and Lower Cretaceous rocks of the North Slope foreland basin. Thrust transport of the Arctic foothills assemblage more than 40 km from south of the Doonerak anticline took place during the Early Cretaceous, but thrusting that deformed rocks of the North Slope foreland basin took place during the early Tertiary, with the vertical uplift of the Doonerak anticline being a late-formed feature. Conclusions based on the retrodeformed cross section contrast significantly with previous work in which the Upper Devonian and stratigraphically higher rocks north of the Doonerak anticline are considered part of the Endicott Mountains allochthon, a regional allochthon that extends the breadth of the Brooks Range, In these models, Upper Devonian and younger rocks in the northcentral Brooks Range have been thrust-transported 90 or 200 km from south of the Doonerak anticline, and emplacement of the allochthon could reflect as much as 885 km of tectonic shortening, The Lower Mississippian and stratigraphically higher rocks together with the underlying basement in the northeast part of the anticline are considered to be in a window in the Endicott Mountains allochthon and to extend northward beneath allochthonous Upper Devonian and stratigraphically higher rocks in the north-central Brooks Range. Lithofacies patterns in rocks in the central Brooks Range are consistent with the retrodeformed cross section and imply plausible Upper Devonian and Carboniferous depositional systems. Thick Upper Devonian and Lower Mississippian(?) elastic prisms were deposited in basins north of the Doonerak anticline. Mississippian carbonate rocks that overlie these elastic prisms were deposited in differentially subsiding shelf environments that included rocks in the Doonerak anticline. Restored across the Blarney Creek thrust, the Mississippian shelf carbonate rocks that presently lie north of the Doonerak anticline are those that were deposited on basement in the anticline. A carbonate ramp at the south edge of these shelf deposits extends east-southeast across the central Brooks Range and in the retrodeformed section lies south of the Doonerak anticline where Upper and Middle(?) Devonian shaly rocks thicken to the south. Unrestored, the ramp would extend across the Doonerak anticline. Restored Late Devonian and Carboniferous lithofacies patterns in the central Brooks Range also are plausible from a regional perspective and have implications for exploration of basins under the Arctic coastal plain. The Late Devonian to Early Mississippian(?) basins in the north-central Brooks Range are part of a system of Early(?) Devonian to Early Mississippian(?) elastic basins that extend the length of the Brooks Range and include basins under the Arctic coastal plain. These basins are a template for depositional patterns in overlying rocks. Marine shelves between these basins where Mississippian strata unconformably lie on basement, such as in the northeastern Brooks Range and the Doonerak anticline, have depositional histories that are in contrast to areas that overlie the basins. The resulting stratigraphic framework, together with the structural framework in the basement rocks that controlled the basins: has had a profound effect on the structural style of the fold belt, the salient effect being folds and thrust faults that are not orthogonal to the direction of structural transport. Stratigraphic relations exposed in the fold belt, especially the distribution of potential source rocks, likely model little-explored basins that underlie the North Slope foreland basin. C1 US GEOL SURVEY, BRANCH ALASKAN GEOL, MENLO PK, CA 94025 USA. RP KELLEY, JS (reprint author), US GEOL SURVEY, BRANCH ALASKAN GEOL, 4200 UNIV DR, ANCHORAGE, AK 99508 USA. NR 94 TC 7 Z9 7 U1 0 U2 1 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD AUG PY 1995 VL 79 IS 8 BP 1087 EP 1116 PG 30 WC Geosciences, Multidisciplinary SC Geology GA RN013 UT WOS:A1995RN01300001 ER PT J AU KELLOGG, KS SCHMIDT, CJ YOUNG, SW AF KELLOGG, KS SCHMIDT, CJ YOUNG, SW TI BASEMENT AND COVER-ROCK DEFORMATION DURING LARAMIDE CONTRACTION IN THE NORTHERN MADISON RANGE (MONTANA) AND ITS INFLUENCE ON CENOZOIC BASIN FORMATION SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID SOUTHWESTERN MONTANA; STRATIGRAPHY; FORELAND; HISTORY; BELT AB Two major Laramide fault systems converge in the northwestern Madison Range: the northwest-striking, southwest-vergent Spanish Peaks reverse fault and the north-striking, east-vergent Hilgard thrust system, Analysis of foliation attitudes in basement gneiss north and south of the Spanish Peaks fault indicates that the basement in thrusted blocks of the Hilgard thrust system has been rotated by an amount similar to that of the basement-cover contact. Steeply dipping, north-striking breccia zones enclosing domains of relatively undeformed basement may have permitted domino-style rotation of basement blocks during simple shear between pairs of thrusts. In most places along the Hilgard thrust system, a large basement overhang, produced by thrusting of Archean blocks above rocks as young as Late Cretaceous, overlies a tight footwall syncline, This tight folding is largely concentric and was accommodated by flexural slip, resulting in severe crowding in synclinal hinges that resulted in observed or inferred features such as bedding-plane slip, imbricate and out-of-syncline thrusting, and hinge collapse. The north-striking Madison normal fault system, a zone of Tertiary and Quaternary valley-forming normal faults, is approximately parallel to the Hilgard thrust system, In some places, normal faults are reactivated thrusts on which large basement overhangs of the Hilgard thrust system were dropped back into the Madison Valley and covered by Tertiary basin-fill deposits, leaving only the rocks of the footwall synclines exposed. In other places, both the thrusted Archean blocks and the near-isoclinal footwall synclines are well preserved. This paired fault system (the Madison normal fault system and the Hilgard thrust system) of the northern Madison Range is strikingly similar to other paired systems in southwestern Montana along and adjacent to the western margins of the Ruby Range, Snowcrest Range, Greenhorn Range, Tobacco Root Mountains, and Bridger Range, Such systems may be the result of collapse of the crestal zones of large Laramide basement uplifts (arches) during Tertiary extension. No hydrocarbon discoveries have been made in this unique structural province. However, petroleum exploration here has focused on basement-cored anticlines, both surface and subthrust, related to the two major Laramide fault systems and on the fault-bounded blocks of Tertiary rocks within the post-laramide extensional basins. The interplay of the two Laramide fault systems during both Laramide shortening and Tertiary extension has produced a variety of possible structural traps in the Madison Range that have not yet been thoroughly investigated. C1 WESTERN MICHIGAN UNIV,DEPT GEOL,KALAMAZOO,MI 49008. CONOCO INC,MIDLAND,TX 79705. RP KELLOGG, KS (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 913,DENVER,CO 80225, USA. NR 68 TC 9 Z9 10 U1 1 U2 3 PU AMER ASSN PETROL GEOLOGISTS PI TULSA PA 1444 S BOULDER AVE PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD AUG PY 1995 VL 79 IS 8 BP 1117 EP 1137 PG 21 WC Geosciences, Multidisciplinary SC Geology GA RN013 UT WOS:A1995RN01300002 ER PT J AU MCCABE, GJ FOUNTAIN, AG AF MCCABE, GJ FOUNTAIN, AG TI RELATIONS BETWEEN ATMOSPHERIC CIRCULATION AND MASS-BALANCE AT SOUTH CASCADE GLACIER, WASHINGTON, USA SO ARCTIC AND ALPINE RESEARCH LA English DT Article ID MONTHLY MEAN CIRCULATION; UNITED-STATES; MONTHLY PRECIPITATION; HEIGHT FIELD; FLUCTUATIONS; SPECIFICATION; WINTER; COAST; TIME; LONG AB The yearly net mass balance of South Cascade Glacier, Washington, has decreased since the mid-1970s. Results show that the decrease is primarily caused by a significant decrease in the winter mass balance. The decrease in winter mass balance is caused, in part, by changes in winter mean atmospheric circulation that began during the mid-1970s. Approximately 60% of the variability in winter mass balance can be explained by variations in winter mean 700-mb heights over western Canada. Since the mid-1970s, there has been an increase in winter mean 700-mb heights over western Canada and the northern western contiguous United States and a decrease in winter mean 700-mb heights in the eastern North Pacific Ocean centered near the Aleutian Islands. These changes in atmospheric circulation indicate a decrease in the movement of storms and moisture from the Pacific Ocean into the western contiguous United States. In addition, the increase in winter mean 700-mb heights over western Canada and the northern western contiguous United States indicates an increase in subsidence, which results in a warming and drying of the air that further reduces precipitation and also increases the ratio of rain to snow during the cold season. These factors contribute to below-average winter mass balances. RP MCCABE, GJ (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 412,DENVER,CO 80225, USA. NR 43 TC 54 Z9 54 U1 0 U2 4 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 SN 0004-0851 J9 ARCTIC ALPINE RES JI Arct. Alp. Res. PD AUG PY 1995 VL 27 IS 3 BP 226 EP 233 DI 10.2307/1551953 PG 8 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA RQ581 UT WOS:A1995RQ58100003 ER PT J AU WILES, GC CALKIN, PE POST, A AF WILES, GC CALKIN, PE POST, A TI GLACIER FLUCTUATIONS IN THE KENAI FJORDS, ALASKA, USA - AN EVALUATION OF CONTROLS ON ICEBERG-CALVING GLACIERS SO ARCTIC AND ALPINE RESEARCH LA English DT Article ID EQUILIBRIUM-LINE ALTITUDES; USA AB The histories of four iceberg-calving outlet-glacier systems in the Kenai Fjords National Park underscore the importance of fiord depth, sediment supply, and fiord geometry on glacier stability. These parameters, in turn, limit the reliability of calving glacier chronologies as records of climatic change. Tree-ring analysis together with radiocarbon dating show that the Northwestern and McCarty glaciers, with large drainage basins, were advancing in concert with nearby land-terminating glaciers about A.D. 600. After an interval of retreat and possible nonclimatically induced extension during the Medieval Warm Period, these ice margins advanced again through the Little Ice Age and then retreated synchronously with the surrounding land-terminating glaciers about A.D. 1900. In contrast, Holgate and Aialik glaciers, with deeper fiords and smaller basins, retreated about 300 yr earlier. Reconstructions of Little Ice Age glaciers suggest that equilibrium-line altitudes of Northwestern and McCarty glaciers were, respectively, 270 and 500 m lower than now. Furthermore, the reconstructions show that these two glaciers were climatically sensitive when at their terminal moraines. However, with ice margins at their present recessional positions and accumulation area ratios between 0.8 and 0.9, only McCarty Glacier shows evidence of advance. Aialik and Holgate glaciers were climatically insensitive during the Little Ice Age maxima and remain insensitive to climate. C1 SUNY BUFFALO,DEPT GEOL,BUFFALO,NY 14260. USGS,VASHON,WA 98070. RP WILES, GC (reprint author), COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,TREE RING LAB,PALISADES,NY 10964, USA. NR 39 TC 23 Z9 25 U1 0 U2 4 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 SN 0004-0851 J9 ARCTIC ALPINE RES JI Arct. Alp. Res. PD AUG PY 1995 VL 27 IS 3 BP 234 EP 245 DI 10.2307/1551954 PG 12 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA RQ581 UT WOS:A1995RQ58100004 ER PT J AU VANARSDALE, RB WILLIAMS, RA SCHWEIG, ES SHEDLOCK, KM ODUM, JK KING, KW AF VANARSDALE, RB WILLIAMS, RA SCHWEIG, ES SHEDLOCK, KM ODUM, JK KING, KW TI THE ORIGIN OF CROWLEYS-RIDGE, NORTHEASTERN ARKANSAS - EROSIONAL REMNANT OR TECTONIC UPLIFT SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID REELFOOT RIFT; MISSISSIPPI EMBAYMENT; ZONE AB The geomorphology of Crowley's Ridge, apparent Quaternary reactivation of the ridge-bounding faults, and orientation of the faults to the present stress field suggest that the faults bounding Crowley's Ridge and the western margin of the Reelfoot rift may be seismogenic. Fifteen high-resolution seismic reflection lines were acquired across and adjacent to the margins of Crowley's Ridge to test the hypothesis that Crowley's Ridge is fault bounded. Eleven of the reflection lines were 24-channel Mini-Sosie data with 1-sec record length and four lines were 24-channel shotgun-source data with 0.25-sec record length. Nine lines traversed the margins and adjacent areas of the northern segment of the ridge near Jonesboro, Arkansas, and the other six were located south of Jonesboro on the southern segment. The reflection data show that Paleozoic through Eocene Wilcox sections have been uplifted beneath Crowley's Ridge from 60 to 30 m across ridge-bounding faults. However, Eocene or Pliocene-Pleistocene near-surface strata appear to be displaced a maximum of 7.5 m. Based on reflection and geomorphologic data, we believe that reactivation of the bounding faults of Crowley's Ridge occurred concurrently with and strongly influenced Wisconsin denudation of the Mississippi valley. C1 US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,DENVER,CO 80225. MEMPHIS STATE UNIV,CTR EARTHQUAKE RES & INFORMAT,US GEOL SURVEY,MEMPHIS,TN 38152. RP VANARSDALE, RB (reprint author), MEMPHIS STATE UNIV,DEPT GEOL SCI,MEMPHIS,TN 38152, USA. NR 45 TC 29 Z9 29 U1 1 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1995 VL 85 IS 4 BP 963 EP 985 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT431 UT WOS:A1995RT43100001 ER PT J AU MADOLE, RF SCHUSTER, RL SARNAWOJCICKI, AM AF MADOLE, RF SCHUSTER, RL SARNAWOJCICKI, AM TI RIBBON CLIFF LANDSLIDE, WASHINGTON, AND THE EARTHQUAKE OF 14 DECEMBER 1872 SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID MOUNT AB Estimates of the epicentral location and maximum intensity of the earthquake of 14 December 1872, the largest and oldest historic earthquake documented in the Pacific Northwest, are controversial largely because the estimates are based on ground effects. The Ribbon Cliff landslide is one of the more critical ground effects used to argue that the epicenter was in the vicinity of Lake Chelan in central Washington. Sketchy historical accounts link the Ribbon Cliff landslide to the 1872 earthquake, but a subsequent study disputed the historical accounts and, on the basis of dendrochronology, concluded that the landslide occurred more than 100 yr prior to the earthquake. However, Quaternary stratigraphic relations and the results of multiple dating techniques reported here indicate that the main Ribbon Cliff landslide probably occurred within a 14-yr period that includes the time of the 1872 earthquake. Although our study supports the historical accounts that link the landslide to the December 1872 earthquake, it does not prove that seismic shaking triggered the landslide. Geomorphic and stratigraphic relations show that Ribbon Cliff has a long and complex history and that the landslide was not primarily a rockfall-rockslide that originated from the cliff itself, as some believe, but rather that the main failure occurred in colluvium that had accumulated beneath the cliff. Four colluvial units and two volcanic ash deposits, the Mazama ash bed (erupted about 6.8 ka), and the Mount St. Helens set W (erupted about 1480 A.D.), underlie the slopes below Ribbon Cliff. Most of the colluvium involved in the landslide accumulated after deposition of the Mazama ash bed. Loss of support at the foot of the colluvial wedge because of undercutting by the Columbia River probably was an important contributing factor to slope failure. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP MADOLE, RF (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 966,BOX 25046,DENVER,CO 80225, USA. NR 28 TC 1 Z9 1 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1995 VL 85 IS 4 BP 986 EP 1002 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT431 UT WOS:A1995RT43100002 ER PT J AU MEREMONTE, M GOMBERG, J CRANSWICK, E AF MEREMONTE, M GOMBERG, J CRANSWICK, E TI CONSTRAINTS ON THE 29 JUNE 1992 LITTLE-SKULL-MOUNTAIN, NEVADA, EARTHQUAKE SEQUENCE PROVIDED BY ROBUST HYPOCENTER ESTIMATES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOURCE PARAMETERS; CALIFORNIA; BENEATH; VALLEY AB The M(s) 5.4 Little Skull Mountain earthquake of 29 June 1992 occurred within 21 km of Yucca Mountain, Nevada, the site of a proposed high-level nuclearwaste repository. Data from a dense portable seismic network have enabled us to examine the faulting process in detail. Standard linearized least-squares procedures were used to determine hypocenter estimates for all the events. A grid-search technique was applied to test the robustness of estimates of the hypocenters of the mainshock and six of the largest aftershocks. Projection of the mainshock fault plane to the surface, delineated by its focal mechanism and the distribution of aftershocks, defines a strike subparallel to a north-northeast structural trend within Jackass Flats and collinear with the Mine Mountain fault system. This result implies reactivation of mapped faults with no known Quaternary movement, and growth or reactivation of buried faults having no clear surface manifestation. The aftershock distribution suggests that postseismic strain release occurred up-dip from the mainshock on the mainshock fault plane and on several secondary faults. The mainshock focal mechanism and the aftershock distribution indicate a normal-slip rupture on a plane with a strike of N55 degrees E, a dip of 56 degrees, and a rake of - 72 degrees. Results of the grid-search analysis show that the mainshock and three of the largest aftershocks probably occurred on the same fault plane and that the other three occurred off the mainshock fault plane; two on a steeply dipping, N200 degrees E-striking plane (with dextral strike-slip displacements), and the other possibly on a plane conjugate to the mainshock rupture plane (focal mechanism unknown), C1 MEMPHIS STATE UNIV,CTR EARTHQUAKE RES & INFORMAT,MEMPHIS,TN 38152. RP MEREMONTE, M (reprint author), US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225, USA. NR 47 TC 13 Z9 13 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1995 VL 85 IS 4 BP 1039 EP 1049 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT431 UT WOS:A1995RT43100005 ER PT J AU FRANKEL, A AF FRANKEL, A TI SIMULATING STRONG MOTIONS OF LARGE EARTHQUAKES USING RECORDINGS OF SMALL EARTHQUAKES - THE LOMA-PRIETA MAINSHOCK AS A TEST-CASE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID STRONG GROUND MOTION; EMPIRICAL GREENS-FUNCTIONS; TECTONIC STRESS; RUPTURE MODEL; CALIFORNIA; SPECTRA; SLIP; ACCELERATION AB A simple method is developed for predicting ground motions for future large earthquakes for specific sites by summing and filtering recordings of adjacent small earthquakes. This method is tested by simulating strong-motion records for the Loma Prieta earthquake (M 7.0) using aftershocks (M 3.7 to 4.0) recorded at the same sites. I use an asperity rupture model where the rms stress drop averaged over the fault plane is constant with moment. The observed spectra indicate that stress drop remains constant from the M 3 aftershocks up to the M 7 mainshock, about six orders of magnitude in seismic moment. Each simulation sums the seismogram of one aftershock with time delays appropriate for propagating rupture and incorporates directivity and site response. The simulation scales the spectrum in accordance with a constant stress drop, omega-2 source model. In this procedure, the high-frequency energy of the aftershock sum above the corner frequency of the aftershock is not reduced when it is convolved with the mainshock slip velocity function, unlike most previous methods of summation, For most cases, the spectra (0.6 to 20 Hz), peak accelerations, and durations of the simulated mainshock records are in good agreement with the observed strong-motion records, even though only one aftershock waveform was used in each simulation. This agreement indicates that the response of these soil sites is essentially linear for accelerations up to about 0.3 g. The summed aftershock records display the same site-dependent values of f(max) as the mainshock records, implying that f(max) is a site effect rather than a property of the mainshock rupture process. RP FRANKEL, A (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,DENVER,CO 80225, USA. NR 31 TC 63 Z9 68 U1 0 U2 5 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1995 VL 85 IS 4 BP 1144 EP 1160 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT431 UT WOS:A1995RT43100013 ER PT J AU BLACK, TA HARDEN, JW AF BLACK, TA HARDEN, JW TI EFFECT OF TIMBER HARVEST ON SOIL CARBON STORAGE AT BLODGETT-EXPERIMENTAL-FOREST, CALIFORNIA SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Article ID NORTHERN HARDWOODS; ORGANIC-MATTER; NITROGEN; FLOOR; EQUILIBRIUM; ECOSYSTEMS; DIOXIDE; EROSION AB Four plots from a mixed conifer forest were similarly cleared, burned, and replanted at various times over 17 years; a plot logged 79 years before sampling was used as a control. The plots had similar slope (2 to 15%, midslope position), aspect (south to southeast), and soil type (Holland series: mesic Haploxeralf; a Gray Brown Luvisol in the Canadian classification system). Twenty sites at each plot were sampled volumetrically by horizon to 20 cm below the organic - mineral soil boundary. Samples were analyzed for bulk density, organic C, and total N. There was an initial loss (15%) of organic C from the soil within 1 to 7 years, likely the result of oxidation (burning and decomposition) and erosion. For 17 years of forest regrowth, the soil continued to lose C (another 15%), probably owing to decomposition of slash material and possibly erosion, despite the slight accumulation of new litter and roots. After 80 years of regrowth, rates of carbon accumulation exceeded fates of loss, but carbon storage had declined and was not likely to recover to preharvest levels. Timber harvest and site preparation dramatically altered soil C and N distribution, in which C/N ratios after site preparation were initially high throughout the upper 20 cm. Subsequently, C/N ratios became lower with depth and with recovery age. Although stocks of C and N varied considerably among the plots and did not change consistently as a function of recovery age, the C/N ratios did vary systematically with recovery age. We hypothesize that the amount of C ultimately stored in the soil at steady state depends largely on N reserves and potentials, which appear to vary with erosion, intensity of burning, and site treatment. C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 30 TC 36 Z9 43 U1 4 U2 13 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0045-5067 J9 CAN J FOREST RES JI Can. J. For. Res.-Rev. Can. Rech. For. PD AUG PY 1995 VL 25 IS 8 BP 1385 EP 1396 DI 10.1139/x95-151 PG 12 WC Forestry SC Forestry GA RV273 UT WOS:A1995RV27300018 ER PT J AU DOBKIN, DS RICH, AC PRETARE, JA PYLE, WH AF DOBKIN, DS RICH, AC PRETARE, JA PYLE, WH TI NEST-SITE RELATIONSHIPS AMONG CAVITY-NESTING BIRDS OF RIPARIAN AND SNOWPOCKET ASPEN WOODLANDS IN THE NORTHWESTERN GREAT-BASIN SO CONDOR LA English DT Article DE ASPEN WOODLAND; CAVITY NESTERS; CAVITY ORIENTATION; GREAT BASIN; NEST-SITE CHARACTERISTICS; NORTHERN FLICKER; RED-NAPED SAPSUCKER; RIPARIAN WOODLAND ID RED-BELLIED WOODPECKERS; TREE SWALLOWS; EUROPEAN STARLINGS; HOUSE WRENS; SAPSUCKERS SPHYRAPICUS; EASTERN BLUEBIRDS; BRITISH-COLUMBIA; TRANSECT COUNTS; SELECTION; COMPETITION AB We examined nest-site and nest-cavity characteristics for six species of cavity-nesting birds in montane riparian and snowpocket aspen (Populus tremuloides) woodlands in the northwestern Great Basin. Live trees and snags with DBH >24 cm were favored as nest sites by all species. Red-naped Sapsuckers (Sphyrapicus nuchalis) and Northern Flickers (Colaptes auratus) provided different sizes of nest cavities for a suite of nonexcavator species. Flickers preferentially nested in snags; sapsuckers nested primarily in live trees, but used live trees and snags in proportion to their availabilities. Relative abundances of excavators and nonexcavators were associated positively with numbers of cavities. Nest-site variables overlapped extensively among species; Tree Swallows (Tachycineta bicolor) relied heavily on sapsuckers for provision of nest cavities, European Starlings (Sturnus vulgaris) and Mountain Bluebirds (Sialia currucoides) primarily used flicker-excavated cavities, and House Wrens (Troglodytes aedon) used nest cavities across the broadest range of nest-site characteristics. Compass orientation of nest-cavity entrances was strongly bimodal, with most facing east or southwest. Cavity entrances of species that foraged largely outside of riparian woodlands were oriented toward woodland edge, in contrast to nest cavities used by species that foraged largely within riparian woodlands. Snowpocket woodlands were much more extensive than riparian aspen, but birds strongly preferred riparian aspen stands as nesting habitats, presumably due to the scarcity of large aspen in snowpockets. Nest cavities appear to be a limiting resource with high potential for interspecific nest-site competition in these woodlands. Decades of livestock overuse and fire suppression have greatly diminished the availability of large aspen in riparian habitats throughout the region. C1 US FISH & WILDLIFE SERV,SHELDON HART MT REFUGE COMPLEX,LAKEVIEW,OR 97630. RP DOBKIN, DS (reprint author), HIGH DESERT ECOL RES INST,15 SW COLORADO AVE,SUITE 300,BEND,OR 97702, USA. NR 71 TC 76 Z9 77 U1 2 U2 23 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 SN 0010-5422 J9 CONDOR JI Condor PD AUG PY 1995 VL 97 IS 3 BP 694 EP 707 DI 10.2307/1369178 PG 14 WC Ornithology SC Zoology GA RT275 UT WOS:A1995RT27500007 ER PT J AU WAGNER, TP DONNELLYNOLAN, JM GROVE, TL AF WAGNER, TP DONNELLYNOLAN, JM GROVE, TL TI EVIDENCE OF HYDROUS DIFFERENTIATION AND CRYSTAL ACCUMULATION IN THE LOW-MGO, HIGH-AL2O3 LAKE BASALT FROM MEDICINE LAKE VOLCANO, CALIFORNIA SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID HIGH-ALUMINA BASALTS; CRATER LAVA-FIELD; NORTHERN CALIFORNIA; PHASE-RELATIONS; ISLAND-ARC; ANDESITE; MAGMA; ORIGIN; H2O; GENERATION AB The late Pleistocene Lake Basalt of Medicine Lake volcano, California is comprised of variably porphyritic basalt and basaltic andesite flows and scoria. These eruptives are similar in composition and phenocryst abundance to the low-MgO, high-Al2O3 mafic magmas common in convergent margin settings. The petrogenesis of the magmas that produced the Lake Basalt has been inferred from field relations, melting experiments and subsequent major and trace element modeling. Their formation involved both hydrous differentiation and plagioclase accumulation and thus the Lake Basalt can be used to constrain the relative contributions of these processes to the production of high-Al2O3 arc basalt. Phenocryst-poor lavas of the Lake Basalt formed by hydrous differentiation; their compositions and observed phenocrysts were reproduced in 1 kbar, H2O-saturated melting experiments. Anorthite-rich plagioclase compositions of the lavas of the Lake Basalt necessitate crystallization from melts with between 4 and 6 wt% dissolved H2O. Phenocryst-rich lavas of the Lake Basalt, with 18 modal% phenocrysts and greater, formed by pla gioclase accumulation in magmas similar to the phenocryst-poor lavas. This interpretation is supported by the depleted incompatible element abundances and enriched Sr/Zr ratio of the more porphyritic lavas relative to the phenocryst-poor lavas. We model the formation of the Lake Basalt as a two-stage process that combines a differentiation model and a plagioclase accumulation model. Stage one involved hydrous fractionation, granitic assimilation and mixing with undifferentiated parent magma. This process generated lavas with up to 19.2 wt% Al2O3 and 7 modal% phenocrysts. In stage two, plagioclase accumulated in these liquids and produced more aluminous and porphyritic lavas with up to 21.8 wt% Al2O3 and 33 modal% phenocrysts. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP WAGNER, TP (reprint author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA. RI Grove, Timothy/M-9638-2013 OI Grove, Timothy/0000-0003-0628-1969 NR 39 TC 31 Z9 32 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD AUG PY 1995 VL 121 IS 2 BP 201 EP 216 DI 10.1007/s004100050099 PG 16 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RT969 UT WOS:A1995RT96900007 ER PT J AU JACKSON, HR GRANTZ, A REID, I MAY, SD HART, PE AF JACKSON, HR GRANTZ, A REID, I MAY, SD HART, PE TI OBSERVATIONS OF ANOMALOUS OCEANIC-CRUST IN THE CANADA BASIN, ARCTIC-OCEAN SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID AGE AB We present a seismic reflection profile and coincident refraction data in deep water north of the Northwind Ridge, in the Canada Basin. The reflection profile shows a package of bright events, which are locally nonparallel and discontinuous, about 2.5 s below the seafloor. These bright reflectors are of interest because previous reflection profiles in the Canada Basin have not penetrated the coherent flat-lying events, which are typical of bedded sedimentary rocks. These prominent reflections are recorded on the refraction profile as wide-angle reflections, and the locally nonparallel and discontinuous event as a refraction. On the refraction profile the nonparallel and discontinuous event exhibits lower frequencies and has an associated refraction with a velocity of 4.5 km/s and a high gradient. This event is interpreted as representing the top of oceanic layer 2, which is observed for the first time in the Canada Basin. Three kilometres beneath layer 2 a velocity of 7.2-7.5 km/s is measured. This layer could represent either a high-velocity layer 3 or serpentinized mantle. Based on comparison with the eastern Grand Banks and the west Iberian and Labrador Sea margins the interpretation of serpentinized mantle is preferred. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP JACKSON, HR (reprint author), GEOL SURVEY CANADA,ATLANTIC GEOSCI CTR,BOX 1006,DARTMOUTH,NS B2Y 4A2,CANADA. NR 19 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD AUG PY 1995 VL 134 IS 1-2 BP 99 EP 106 DI 10.1016/0012-821X(95)00108-O PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RT480 UT WOS:A1995RT48000008 ER PT J AU YANOSKY, TM HUPP, CR HACKNEY, CT AF YANOSKY, TM HUPP, CR HACKNEY, CT TI CHLORIDE CONCENTRATIONS IN GROWTH RINGS OF TAXODIUM-DISTICHUM IN A SALTWATER-INTRUDED ESTUARY SO ECOLOGICAL APPLICATIONS LA English DT Article DE BALDCYPRESS; DENDROCHEMISTRY; FORESTED WETLANDS; SALTWATER INTRUSION; SEA LEVEL RISE; TREE RINGS; WETLAND LOSS ID GROUNDWATER CONTAMINATION; TREE RINGS; LOUISIANA; CHEMISTRY; FORESTS; IMPACT; LEVEL AB Element analysis by proton induced X-ray emission spectroscopy was performed on growth rings of baldcypress (Taxodium distichum) growing within the Cape Fear River estuary, North Carolina, USA. Trees from estuarine reaches heavily intruded by saltwater flooding contained larger concentrations of chloride, bromide, and sodium than did trees from less intruded reaches. At three intruded sites, trees nearest open water contained larger concentrations of these elements within outermost sapwood rings than did trees farther from open water and presumably flooded less often. Chloride was translocated from outer to inner sapwood rings of saltwater-intruded trees, resulting in larger concentrations within heartwood than within the inner sapwood. Chloride concentrations along the heartwood radius were used to estimate the position of the heartwood-sapwood interface during the beginning stages of intrusion, thus permitting historical estimates of the local onset of intrusion. Element analysis of the wood of baldcypress may aid assessments of tree growth and mortality in regions already subjected to saline flooding, and in coastal forests at risk from predicted sea level rises. C1 UNIV N CAROLINA,DEPT BIOL SCI,WILMINGTON,NC 28403. RP YANOSKY, TM (reprint author), US GEOL SURVEY,MAIL STOP 461,RESTON,VA 22092, USA. NR 27 TC 28 Z9 32 U1 1 U2 14 PU ECOLOGICAL SOC AMER PI TEMPE PA ARIZONA STATE UNIV CENTER ENVIRONMENTAL STUDIES, TEMPE, AZ 85287 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1995 VL 5 IS 3 BP 785 EP 792 DI 10.2307/1941986 PG 8 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA RM902 UT WOS:A1995RM90200022 ER PT J AU PLUMLEE, GS GOLDHABER, MB ROWAN, EL AF PLUMLEE, GS GOLDHABER, MB ROWAN, EL TI POTENTIAL ROLE OF MAGMATIC GASES IN THE GENESIS OF ILLINOIS-KENTUCKY FLUORSPAR DEPOSITS - IMPLICATIONS FROM CHEMICAL-REACTION PATH MODELING SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID THERMAL EVOLUTION; FLUID INCLUSION; STABLE ISOTOPE; NORTH-AMERICA; ORE FLUID; DISTRICT; MINERALS; EXPLORATION; GROUNDWATER; SYSTEMS AB In this gaper, we present results of reaction path calculations using the chemical speciation and reaction path Programs SOLVEQ and CHILLER to model possible fluorite deposition mechanisms in the Illinois-Kentucky fluorspar district. Input to the reaction path calculations were the temperatures, salinities, and concentrations of major cation and anions (Na, K, Cl, SO4, etc.) and dissolved gases (H2S, CO2, etc.) in the hydrothermal fluids, based on published fluid inclusion data and unpublished fluid inclusion gas compositions. Fluid pH values and concentrations of fluorine and various metals were then calculated assuming saturation with observed hydrothermal minerals. We assumed saturation with fluorite, dolomite, quartz, muscovite (approximating illite), anhydrite, sphalerite, galena, and pyrite. Fluorite ore deposition mechanisms which we initially modeled include (1) simple cooling (from 150 degrees-140 degrees C, based on data and conclusions of Richardson and Pinckney, 1984), (2) reactions of the hydrothermal fluids with limestones (based upon the observed extensive replacement of limestones by fluorite), (3) combinations of cooling and limestone reaction, (4) isothermal or near-isothermal boiling of the fluids in response to pressure drops, and (5) mixing of two fluids with different Ca and F contents. Using the assumed initial fluid composition discussed above, the modeling predicts that none of these mechanisms accurately reproduces the observed fluorite-dominant mineralization stages and limestone replacement features. We then modeled how interactions of the hydrothermal fluids at 300 degrees C with HF and CO2 (approximating a CO2- and HF-bearing gas phase expelled from a crystallizing alkalic magma) might affect fluid chemistries and results of the above deposition mechanisms. The influence of alkalic magmatism on Illinois-Kentucky fluorspar district mineralization is probable based on the geologic relations of the district. Titration of 0.5 g HF and 0.5 g CO2 into 1 kg of a fluorspar fluid composition produces extensive fluorite precipitation and acidic (pH 2.5 or lower), F-rich, Ca-poor fluids. Cooling of these fluids to 150 degrees C leads to further fluorite precipitation. Other possible magmatic gas compositions were modeled and yielded generally comparable results. Paths modeling subsequent reactions of these modified fluids at 150 degrees C with limestone (to produce the manto, Cave-In-Rock-style ores) predict extensive replacement of limestone initially by large amounts of fluorite; when the pH increases to above 4.5, dolomite and anhydrite also precipitate. When cooled from 150 degrees to 142 degrees C, these fluids produce large amounts of fluorite with lesser quartz. Isothermal or near-isothermal boiling reaction paths predict formation of somewhat lesser amounts of fluorite. Reaction paths modeling the mixing of the acidic, F-rich fluids with Ca-rich, F-poor fluids also predict copious fluorite precipitation with no associated minerals. Thus, cooling or mixing of a fluid previously acidified by HF could produce open-space, vein-style fluorspar mineralization. These results indicate that the fluids responsible for Illinois- Kentucky fluorspar mineralization were most likely quite acidic (pH < 4) and rich in fluorine in order to produce the fluorite-rich, dolomite-poor mineral assemblages and extensive dissolution of host limestones. A possible source for the acid and fluorine may have been HF-rich gases which were expelled from alkalic magmas and then incorporated by migrating basinal brines. A possible sequence for Illinois-Kentucky fluorspar district mineralization which fits the available data is an initial major gas explosion to form the Hicks Dome cryptovolcano, followed by continued, less violent leakage of magmatic gases from alkaline igneous sources. These magmatic gases could have migrated upward not only in the immediate vicinity of Hicks Dome itself but also along major Illinois-Kentucky fluorspar district faults which cut crystalline basement; titration of the gases into basinal brines at depth led to preferential mineralization of these structures. An analysis of the geologic setting of other fluorite deposits ana districts worldwide suggests that involvement of magmatic gases is probable for many of these districts as well. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP PLUMLEE, GS (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 973,DENVER,CO 80225, USA. NR 57 TC 23 Z9 25 U1 1 U2 5 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD AUG PY 1995 VL 90 IS 5 BP 999 EP 1011 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH194 UT WOS:A1995TH19400001 ER PT J AU WOITSEKHOWSKAYA, MB HEMLEY, JJ AF WOITSEKHOWSKAYA, MB HEMLEY, JJ TI MODELING METAL TRANSPORT AND DEPOSITION IN BUTTE-TYPE HYDROTHERMAL SYSTEMS SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Note ID EQUILIBRIA; FLUIDS; GASES C1 INST MINERAL & PETR, NOVOSIBIRSK 630090, RUSSIA. US GEOL SURVEY, RESTON, VA 22092 USA. NR 22 TC 4 Z9 4 U1 0 U2 0 PU SOC ECONOMIC GEOLOGISTS, INC PI LITTLETON PA 7811 SCHAFFER PARKWAY, LITTLETON, CO 80127 USA SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD AUG PY 1995 VL 90 IS 5 BP 1329 EP 1337 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH194 UT WOS:A1995TH19400019 ER PT J AU PLUMLEE, GS LEACH, DL HOFSTRA, AH LANDIS, GP ROWAN, EL VIETS, JG AF PLUMLEE, GS LEACH, DL HOFSTRA, AH LANDIS, GP ROWAN, EL VIETS, JG TI CHEMICAL-REACTION PATH MODELING OF ORE DEPOSITION IN MISSISSIPPI VALLEY-TYPE PB-ZN DEPOSITS OF THE OZARK REGION, US MIDCONTINENT - A REPLY SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Discussion ID FOCUSED FLUID-FLOW; GROUNDWATER-FLOW; SPHALERITE C1 US GEOL SURVEY,MENLO PK,CA 94025. RP PLUMLEE, GS (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 973,DENVER,CO 80225, USA. NR 16 TC 0 Z9 0 U1 1 U2 3 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD AUG PY 1995 VL 90 IS 5 BP 1346 EP 1349 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH194 UT WOS:A1995TH19400024 ER PT J AU KIDO, MH ASQUITH, A AF KIDO, MH ASQUITH, A TI ATTRACTION OF HAWAIIAN AQUATIC INSECTS TO PEST TEPHRITID PARAKAIROMONE LURES SO ENVIRONMENTAL ENTOMOLOGY LA English DT Article DE CHIRONOMIDAE; HAWAIIAN STREAMS; FRUIT FLY ERADICATION; NONTARGET INSECTS ID FRUIT-FLY DIPTERA AB Attraction to 3 pest tephritid parakairomone lures (methyl eugenol, trimedlure, and cuelure) or aquatic insects associated with swift-water habitat in representative Hawaiian stream systems is evaluated. Results indicate no attractancy of aquatic insects to methyl eugenol or cuelure. Attractancy is suggested for Hawaiian Orthocladiinae (Biptera: Chironomidae) to trimedlure; however, significant negative effects to stream insect communities are unlikely because total captures were low and likely limited to this family. High variability in aquatic insect response, both within and between streams as well as possible susceptibility to bucket traps suggest that weak-acting lures such as trimedlure are influenced by multiple variables (trap type and placement, season, insect phenology, population characteristics and dynamics, and stream ecotype). C1 US FISH & WILDLIFE SERV,PACIFIC ISL OFF,HONOLULU,HI 96813. RP KIDO, MH (reprint author), UNIV HAWAII,KAUAI RES FACIL,7370A KUAMOO RD,KAPAA,HI 96746, USA. NR 18 TC 6 Z9 8 U1 0 U2 0 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 SN 0046-225X J9 ENVIRON ENTOMOL JI Environ. Entomol. PD AUG PY 1995 VL 24 IS 4 BP 810 EP 816 PG 7 WC Entomology SC Entomology GA RP244 UT WOS:A1995RP24400004 ER PT J AU HOTHEM, RL ROSTER, DL KING, KA KELDSEN, TJ MAROIS, KC WAINWRIGHT, SE AF HOTHEM, RL ROSTER, DL KING, KA KELDSEN, TJ MAROIS, KC WAINWRIGHT, SE TI SPATIAL AND TEMPORAL TRENDS OF CONTAMINANTS IN EGGS OF WADING BIRDS FROM SAN-FRANCISCO BAY, CALIFORNIA SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE WADING BIRDS; EGGS; SAN FRANCISCO BAY; CONTAMINANTS; ORGANOCHLORINES ID CROWNED NIGHT-HERONS; GREAT-LAKES; ORGANOCHLORINE RESIDUES; NEST SUCCESS; SELENIUM; DDE; REPRODUCTION; TOXICITY; MALLARDS; MERCURY AB Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time. At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element. C1 US FISH & WILDLIFE SERV, SAN FRANCISCO BAY NATL WILDLIFE REFUGE, NEWARK, CA 94560 USA. US FISH & WILDLIFE SERV, ECOL SERV, PHOENIX, AZ 85021 USA. NATL BIOL SERV, MIDCONTINENT ECOL SCI CTR, FT COLLINS, CO 80525 USA. RP HOTHEM, RL (reprint author), NATL BIOL SERV, PATUXENT ENVIRONM SCI CTR, PACIFIC RES GRP, DAVIS, CA 95616 USA. NR 59 TC 34 Z9 34 U1 3 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD AUG PY 1995 VL 14 IS 8 BP 1319 EP 1331 DI 10.1897/1552-8618(1995)14[1319:SATTOC]2.0.CO;2 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RK786 UT WOS:A1995RK78600008 ER PT J AU BOHANNON, RG PARSONS, T AF BOHANNON, RG PARSONS, T TI TECTONIC IMPLICATIONS OF POST-30 MA PACIFIC AND NORTH-AMERICAN RELATIVE PLATE MOTIONS SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Review ID SAN-ANDREAS FAULT; WESTERN TRANSVERSE RANGES; CENTRAL CALIFORNIA MARGIN; METAMORPHIC CORE COMPLEXES; SOUTHWESTERN UNITED-STATES; SOUTHERN-CALIFORNIA; CONTINENTAL BORDERLAND; OCEANIC LITHOSPHERE; COASTAL CALIFORNIA; BAJA-CALIFORNIA AB The Pacific plate moved northwest relative to North America since 42 Ma. The rapid half rate of Pacific-Farallon spreading allowed the ridge to approach the continent at about 29 Ma. Extinct spreading ridges that occur. offshore along 65% of the margin (Lonsdale, 1991) document that fragments of the subducted Farallon slab became captured by the Pacific plate and assumed its motion prior to the actual subduction of the spreading ridge. This plate-capture process can be used to explain much of the post-29 Ma Cordilleran North America extension, strike slip, and the inland jump of oceanic spreading in the Gulf of California. The Pacific and North American contact zone lengthened with each successive plate capture event, underpinning the parts of western North America directly inland with a strong plate undergoing Pacific relative motion. We suggest that much of the post-29 Ma continental tectonism is the result of the strong traction imposed on the deep part of the continental crust by the gently inclined slab of subducted oceanic lithosphere as it moved to the northwest relative to the overlying continent. The plate-capture hypothesis is distinctly different from theories involving shallow slab gaps. Kinematic problems associated with shallow slab-gap models cause us to question them. This conclusion is consistent with seismic refraction interpretations that suggest there is an inclined layer with high velocities like that of basalt or gabbro at the base of the continental crust beneath much of the Californian margin and the documented reduction of slab-pull forces and density associated with young subducting slabs. Thermal and theologic modeling suggests that coastal California was a strong zone at all depths allowing it to be firmly linked to Pacific motion. Our model shows that deformed regions such as the basin and range and borderland provinces developed in predicted weak parts of the crustal section, but they have been incompletely linked to the deep plate across the ductile middle and lower crustal layer. RP BOHANNON, RG (reprint author), US GEOL SURVEY,MS 999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Parsons, Tom/A-3424-2008; OI Parsons, Tom/0000-0002-0582-4338 NR 121 TC 121 Z9 123 U1 2 U2 10 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD AUG PY 1995 VL 107 IS 8 BP 937 EP 959 DI 10.1130/0016-7606(1995)107<0937:TIOPMP>2.3.CO;2 PG 23 WC Geosciences, Multidisciplinary SC Geology GA RM681 UT WOS:A1995RM68100004 ER PT J AU TORGERSEN, T DRENKARD, S STUTE, M SCHLOSSER, P SHAPIRO, A AF TORGERSEN, T DRENKARD, S STUTE, M SCHLOSSER, P SHAPIRO, A TI MANTLE HELIUM IN-GROUND WATERS OF EASTERN NORTH-AMERICA - TIME AND SPACE CONSTRAINTS ON SOURCES SO GEOLOGY LA English DT Article ID BASINS; FLUXES; HILLS; CRUST; HE-4 AB Mantle helium in continental environments is generally considered to be the result of active volcanism and/or active extension. The latest episodes of volcanism in northeastern North America are the track of the New England hotspot (95-190 Ma) and the closure of the Iapetus sea (before 300 Ma). Thus, the identification of mantle helium in young ground waters of central New England is counter to the conventional, wisdom, On the basis of evaluation of helium evolution in emplaced magmas, we postulate an ''aged'' mantle source for the excess helium component in ground waters of central New England that is either (1) a local, near-surface-emplaced, gas-rich magma that has retained significant volatiles (e.g., in fluid inclusions) or (2) a deeply emplaced gas-rich magma with high initial He-3/He-4 (10(-5)) and helium transport (with dispersion) through the crust over time, This gas-rich initial condition may support the concept of a volatile-enriched mantle wedge and thus explain the increased buoyancy flux of the New England hotspot as it traversed eastern North America, as has been suggested by others. C1 LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964. US GEOL SURVEY,RESTON,VA 22092. RP TORGERSEN, T (reprint author), UNIV CONNECTICUT,DEPT MARINE SCI,GROTON,CT 06340, USA. RI Schlosser, Peter/C-6416-2012 OI Schlosser, Peter/0000-0002-6514-4203 NR 21 TC 17 Z9 17 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD AUG PY 1995 VL 23 IS 8 BP 675 EP 678 DI 10.1130/0091-7613(1995)023<0675:MHIGWO>2.3.CO;2 PG 4 WC Geology SC Geology GA RM682 UT WOS:A1995RM68200001 ER PT J AU QUICK, JE SINIGOI, S MAYER, A AF QUICK, JE SINIGOI, S MAYER, A TI EMPLACEMENT OF MANTLE PERIDOTITE IN THE LOWER CONTINENTAL-CRUST, IVREA-VERBANO ZONE, NORTHWEST ITALY SO GEOLOGY LA English DT Article ID IGNEOUS COMPLEX; WESTERN ALPS; SOUTHERN-ALPS; DEEP-CRUSTAL; CENERI ZONES; BALMUCCIA; TRANSITION; MASSIF; MODEL AB The Ivrea-Verbano zone has been cited repeatedly as an exposed pre-Alpine crust-mantle transition on the basis, in part, of the presence of lenses of mantle peridotite and a possible petrologic Moho. A 10-km-thick mafic complex has been described as an intrusion at the contact between the mantle and a thick crustal sequence of metamorphosed wacke and pelitic rocks. The significance of these features is now challenged by new mapping that demonstrates that mantle peridotites in the southern Ivrea-Verbano zone were lenses tectonically interfingered with metasedimentary rocks prior to intrusion of the gabbroic complex. Although it remains possible that the Ivrea-Verbano section exposes part of a complex crust-mantle interface within which crustal and mantle rocks were interleaved, the association of peridotite and metasedimentary rocks is also consistent with assembly in an accretionary wedge. In either case, present exposures are from an unknown distance above the pre-Alpine contiguous mantle and reference to the section as a complete crust-mantle transition could be misleading. C1 UNIV TRIESTE,IST MINERAL & PETROG,I-34100 TRIESTE,ITALY. US GEOL SURVEY,DENVER,CO 80225. RP QUICK, JE (reprint author), MAX PLANCK INST CHEM,SAARSTR 23,POSTFACH 3060,W-6500 MAINZ,GERMANY. OI SINIGOI, Silvano/0000-0001-6812-4083 NR 34 TC 55 Z9 55 U1 0 U2 6 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD AUG PY 1995 VL 23 IS 8 BP 739 EP 742 DI 10.1130/0091-7613(1995)023<0739:EOMPIT>2.3.CO;2 PG 4 WC Geology SC Geology GA RM682 UT WOS:A1995RM68200017 ER PT J AU RICHMOND, GM AF RICHMOND, GM TI DEFINING STRATOTYPES SO GEOTIMES LA English DT Letter RP RICHMOND, GM (reprint author), US GEOL SURVEY,FED CTR,INT COMMISS STRATIG,MS 913,BOX 25046,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD AUG PY 1995 VL 40 IS 8 BP 3 EP 3 PG 1 WC Geosciences, Multidisciplinary SC Geology GA RL876 UT WOS:A1995RL87600008 ER PT J AU BENNETT, JP AF BENNETT, JP TI ALGORITHM FOR RESISTANCE TO FLOW AND TRANSPORT IN SAND-BED CHANNELS SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID SEDIMENT TRANSPORT; SUSPENDED-LOAD; ROUGHNESS; FORMS; DEPTH AB An algorithm is developed that relates depth to discharge and determines bed- and suspended-load transport for the entire range of bed forms found in sand-bed channels; equilibrium-state geometry of lower flow regime bedforms is also predicted. Grain shear stress and form resistance are differentiated using a drag coefficient closure and a two-segment logarithmic velocity profile. A Meyer-Peter-type formulation is used to compute sand transport in the bed-load layer and for computing suspended sand transport, McLean's procedure of 1991 and 1992 is adopted. A bed-form classification scheme is developed that uses a particle size parameter and the transport strength to predict bed-form type; it correctly identifies 73% of the 1,192 mostly flume-scale calibration data sets. For 194 sets of dune-transition bed-form calibration data, a modified version of van Rijn's 1984 bed-form geometry predictor yields a geometric average predicted to observed height ratio of 1.00. After calibration, the algorithm produces overall geometric averages of predicted to observed depth and predicted to observed transport of 1.00. For a verification data set of 855 observations, mostly from rivers and canals, the overall geometric averages of predicted to observed depth and transport are 0.87 and 1.14. RP BENNETT, JP (reprint author), US GEOL SURVEY,MS 413,POB 25046,LAKEWOOD,CO 80225, USA. NR 43 TC 15 Z9 15 U1 1 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD AUG PY 1995 VL 121 IS 8 BP 578 EP 590 DI 10.1061/(ASCE)0733-9429(1995)121:8(578) PG 13 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA RK707 UT WOS:A1995RK70700001 ER PT J AU RICE, KC BRICKER, OP AF RICE, KC BRICKER, OP TI SEASONAL CYCLES OF DISSOLVED CONSTITUENTS IN STREAMWATER IN 2 FORESTED CATCHMENTS IN THE MID-ATLANTIC REGION OF THE EASTERN USA SO JOURNAL OF HYDROLOGY LA English DT Article ID ATMOSPHERIC DEPOSITION; NATIONAL-PARK; UNITED-STATES; SURFACE-WATER; ACIDIFICATION; CHEMISTRY; SULFATE AB Streamwater discharge and chemistry of two small catchments on Catoctin Mountain in north-central Maryland have been monitored since 1982. Repetitive seasonal cycles in streamwater chemistry have been observed each year, along with seasonal cycles in the volume of stream discharge and in groundwater levels. The hypothesis that the observed streamwater chemical cycles are related to seasonal changes in the hydrological flow paths that contribute to streamflow is examined using a combination of data on groundwater levels, shallow and deep groundwater chemistry, streamwater discharge, streamwater chemistry, soil-water. chemistry, and estimates of water residence times. The concentrations of constituents derived from rock weathering, particularly bicarbonate and silica, increase in streamwater during the summer when the water table is below the regolith-bedrock interface and stream discharge consists primarily of deep groundwater from the fractured-bedrock aquifer. Conversely, the concentrations in streamwater of atmospherically derived components, particularly sulfate, increase in winter when the water table is above the regolith-bedrock interface and stream discharge consists primarily of shallow groundwater from the regolith. Tritium and chlorofluorocarbon (CFC) measurements suggest that the groundwater in these systems is young, with a residence time of less than several years. The results of this study have implications for the design of large-scale water-quality monitoring programs. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP RICE, KC (reprint author), US GEOL SURVEY,1936 ARLINGTON BLVD,ROOM 118,CHARLOTTESVILLE,VA 22903, USA. RI Rice, Karen/A-8945-2013; OI Rice, Karen/0000-0002-9356-5443 NR 34 TC 55 Z9 57 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD AUG PY 1995 VL 170 IS 1-4 BP 137 EP 158 DI 10.1016/0022-1694(95)92713-N PG 22 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RH480 UT WOS:A1995RH48000010 ER PT J AU GEIST, D HOWARD, KA LARSON, P AF GEIST, D HOWARD, KA LARSON, P TI THE GENERATION OF OCEANIC RHYOLITES BY CRYSTAL FRACTIONATION - THE BASALT-RHYOLITE ASSOCIATION AT VOLCAN-ALCEDO, GALAPAGOS-ARCHIPELAGO SO JOURNAL OF PETROLOGY LA English DT Article DE GALAPAGOS; OCEANIC RHYOLITES; FRACTIONAL CRYSTALLIZATION; ISABELA ISLAND ID IGNEOUS ROCKS; DIFFERENTIATION PROCESSES; SOUTHEASTERN ICELAND; ISOTOPIC EVIDENCE; SPREADING CENTER; MIDOCEAN RIDGE; 1875 ERUPTION; MAGMA TYPES; CRYSTALLIZATION; PETROGENESIS AB Alcedo volcano is one of six shield volcanoes on Isabela Island in the western Galapagos Islands. Although Alcedo is dominantly basaltic, it is unusual in that it also has erupted similar to 1 km(3) of rhyolite. The rhyolitic phase marked a 10-fold decrease in the mass-eruption rate of the volcano, and the volcano has returned to erupting basalt. The basalts are tholeiitic and range from strongly to sparsely porphyritic. Olivine and plagioclase are the lipuidus Phases in the most primitive basalts. The MgO and Ni concentrations in the most primitive basalts indicate that they have undergone substantial differentiation since extraction from the mantle. The rhyolites contain the assemblage oligoclase-augite-titanomagnetite-fayalite-apatite and sparse xenoliths of quenched basalt and cumulate gabbros. Intermediate rocks are very rare, but some are apparently basalt-rhyolite hybrids, and others resulted from differentiation of tholeiitic magma. Several modeling approaches and Sr-, Nd-, and O-isotopic data indicate that the rhyolites resulted from similar to 90% fractionation (by weight) of plagioclase, augite, titanomagnetite, olivine, and apatite from the most primitive olivine tholeiite. The data are inconsistent with the rhyolites originating by crustal anatexis. The extreme Daly gap may be caused by the large increase in viscosity as the basaltic magma differentiates to intermediate and siliceous compositions; highly evolved magmas are eruptible only after they become saturated with volatiles by second boiling. The close association of the hybrid intermediate magmas and magmatic inclusions with the climactic plinian eruption indicates mixing between mafic and silicic magmas immediately before eruption. Rhyolite production was favored by the decrease in supply of basaltic magma as Alcedo was carried away from the focus of the Galapagos hot-spot. A three-stage model for the magmatic evolution of a Galapagos volcano is proposed In the first stage, the supply of basaltic magma is large. Basaltic magma continually intrudes the subcaldera magma chamber, buffering the magmas' compositional and thermal evolution. As the volcano is carried away from the basaltic source, the magma chamber is allowed to cool and differentiate, as exemplified by Alcedo's rhyolitic phase. Finally, the volcano receives even smaller influx of basalt, so a large magma chamber cannot be sustained, and the volcano shifts to isolated basaltic eruptions. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. WASHINGTON STATE UNIV, DEPT GEOL, PULLMAN, WA 99164 USA. RP GEIST, D (reprint author), UNIV IDAHO, MOSCOW, ID 83844 USA. NR 77 TC 102 Z9 115 U1 3 U2 16 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0022-3530 EI 1460-2415 J9 J PETROL JI J. Petrol. PD AUG PY 1995 VL 36 IS 4 BP 965 EP 982 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RU637 UT WOS:A1995RU63700004 ER PT J AU RICIPUTI, LR JOHNSON, CM SAWYER, DA LIPMAN, PW AF RICIPUTI, LR JOHNSON, CM SAWYER, DA LIPMAN, PW TI CRUSTAL AND MAGMATIC EVOLUTION IN A LARGE MULTICYCLIC CALDERA COMPLEX - ISOTOPIC EVIDENCE FROM THE CENTRAL SAN-JUAN VOLCANIC FIELD SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID OASIS-VALLEY CALDERA; RIO-GRANDE RIFT; ASH-FLOW TUFFS; SOUTHWESTERN COLORADO; CONTINENTAL-CRUST; TIMBER MOUNTAIN; GRANITIC MAGMAS; NORTH-AMERICA; LAACHER-SEE; ND AB The Sr, Nd and Pb isotope compositions of ash-flow tuffs and lavas from the central caldera cluster of the San Juan volcanic field, Colorado, suggest that the silicic magmas were derived by fractional crystallization of mantle-derived basalts, coupled with extensive assimilation of both lower-and upper-crustal components, Temporal trends of increasing epsilon(Nd) values and decreasing Sr-87/Sr-86 ratios of the ash-flow tuffs suggest that extensive crustal hybridization of both upper-and lower-crustal reservoirs occurred as a result of magmatism. Mantle-derived basalts are envisioned to have initially crystallized and significantly interacted with crust near the crust-mantle boundary, creating a hybrid crust that is a mixture of mantle and lower-crustal components. Evolved magmas ascended into the upper crust, where they continued to assimilate and crystallize, modifying the bulk upper-crustal composition through transfer of both lower-crustal and mantle components into the upper crust, strongly affecting the isotopic compositions of the lower and upper crust, Lower-crustal epsilon(Nd) values and Sr-87/Sr-86 ratios are calculated to have shifted > 30-40% toward mantle compositions during these processes, although Pb isotope compositions of the lower crust are not as strongly affected (< 30% shift to mantle compositions). Depending on the extent of upper crust-lower crust recycling, upper-crustal epsilon(Nd) values shift 15-30% toward mantle compositions, Sr-87/Sr-86 ratios shift 20-55% toward lower-crustal and mantle ratios and Pb-206/Pb-204 ratios decrease 15-25% toward lower-crustal ratios. Crustal hybridization during evolution of the central caldera cluster was intense, although hybridization in the upper crust was localized to the region immediately underlying the calderas. Two distinct isotopic cycles are recognized in the ash-flow tuffs, one from 27.8 to 26.9 Ma (first caldera cycle) and the second from 26.4 to 26.1 Ma (San Luis caldera cycle),The break between the two cycles may be due to a shift in the locus of magmatism to the northwest, into an area of relatively unhybridized, original Proterozoic crust, Isotopic compositions of the caldera-related lavas are variable, and unlike the ash-flow tuffs, there are no distinctive temporal trends. The lavas are believed to undergo late-stage evolution in smaller magma chambers surrounding the caldera cluster, where the crust has not been as intensely hybridized. The comparatively large isotopic variability of the lavas reflects the high susceptibility of small magma chambers to isotopic modification during interaction with heterogeneous crust, In contrast, ash-flow magmas evolve in much larger magma chambers which tend to average isotopic heterogeneity of crust and mantle end-members, and the isotopic compositions of the tuffs serve as a better monitor of changes in the average composition of the magmatic system and the crustal column. C1 UNIV WISCONSIN, DEPT GEOL & GEOPHYS, MADISON, WI 53706 USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP RICIPUTI, LR (reprint author), OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, POB 2008, OAK RIDGE, TN 37831 USA. NR 48 TC 33 Z9 33 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 EI 1872-6097 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD AUG PY 1995 VL 67 IS 1-3 BP 1 EP 28 DI 10.1016/0377-0273(94)00097-Z PG 28 WC Geosciences, Multidisciplinary SC Geology GA RV910 UT WOS:A1995RV91000002 ER PT J AU ARMSTRONG, AK RENAULT, JR OSCARSON, RL AF ARMSTRONG, AK RENAULT, JR OSCARSON, RL TI COMPARISON OF HYDROTHERMAL ALTERATION OF CARBONIFEROUS CARBONATE AND SILICLASTIC ROCKS IN THE VALLES CALDERA WITH OUTCROPS FROM THE SOCORRO CALDERA, NEW-MEXICO SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID JEMEZ VOLCANIC FIELD; GEOTHERMAL SYSTEM; EVOLUTION; DEPOSITS; CEMENTS AB Continental Scientific Drilling Program (CSDP) drill hole VC-2B [total depth 1761.7 m (5780 ft); maximum temperature 295 degrees C] was continuously cored through the Sulphur Springs hydrothermal system in the western ring-fracture zone of the 1.14 Ma Valles caldera. Among other units, the hole penetrated 760.2 m (2494.1 ft) of Paleozoic carbonate and siliciclastic strata underlying caldera fill and precaldera volcanic and epiclastic rocks. Comparison of the VC-2B Paleozoic rocks with corresponding lithologies within and around the 32.1 Ma Socorro caldera, 192 km (119 miles) to the south-southwest, provides insight into the variability of alteration responses to similar caldera-related hydrothermal regimes. The Pennsylvanian Madera Limestone and Sandia Formation from VC-2B preserve many of the sedimentological and diagenetic features observed in these units on a regional basis and where unaffected by high temperatures or hydrothermal activity. Micrites in these formations in VC-2B are generally altered and mineralized only where fractured or brecciated, that is, where hydrothermal solutions could invade carbonate rocks which were otherwise essentially impermeable. Alteration intensity (and correspondingly inferred paleopermeability) is only slightly higher in carbonate packstones and grainstones, low to intermediate in siltstones and claystones, and high in poorly cemented sandstones. Hydrothermal fracture-filling phases in these rocks comprise sericite (and phengite), chlorite, allanite, apatite, an unidentified zeolite and sphene in various combinations, locally with sphalerite, galena, pyrite and chalcopyrite. Terrigenous feldspars and clays are commonly altered to chlorite and sericite, and euhedral anhydrite ''porphyroblasts'' with minor chlorite occur in Sandia Formation siltstone. Fossils are typically unaltered, but the walls of some colonial bryozoans in the Madera Limestone are altered to the assemblage chlorite-sericite-epidote-allanite. La, Ce and Nd are present in an unidentified hydrothermal mineral occurring throughout much of the VC-2B Pennsylvanian sequence. Carboniferous carbonate and siliciclastic formations within and around the Socorro caldera show a similar style of alteration and mineralization to their Valles caldera counterparts, but by contrast locally host commercial, caldera-related, base-metal sulfide deposits. As in the Valles rocks, mineralization and alteration in those of the Socorro caldera were strongly controlled by porosity. Unless disrupted by fractures, breccias, or karat cavities (not identified in Valles caldera drill holes), the rocks remained relatively unaltered. Where these features allowed ingress of mineralizing, hydrothermal solutions, base-metal sulfides and rare-earth-element-bearing minerals were precipitated. C1 NEW MEXICO BUR MINES & MINERAL RESOURCES,SOCORRO,NM 87801. US GEOL SURVEY,MENLO PK,CA 94025. RP ARMSTRONG, AK (reprint author), US GEOL SURVEY,NEW MEXICO BUR MINES & MINERAL RESOURCES,SOCORRO,NM 87801, USA. NR 41 TC 2 Z9 2 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD AUG PY 1995 VL 67 IS 1-3 BP 207 EP 220 DI 10.1016/0377-0273(94)00104-O PG 14 WC Geosciences, Multidisciplinary SC Geology GA RV910 UT WOS:A1995RV91000013 ER PT J AU BROWN, CL LUOMA, SN AF BROWN, CL LUOMA, SN TI USE OF THE EURYHALINE BIVALVE POTAMOCORBULA-AMURENSIS AS A BIOSENTINEL SPECIES TO ASSESS TRACE-METAL CONTAMINATION IN SAN-FRANCISCO BAY SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE POTAMOCORBULA AMURENSIS; BIOSENTINEL; TRACE METALS; SAN FRANCISCO BAY; SIZE; GUT CONTENT; VARIABILITY ID MUSSEL MYTILUS-EDULIS; MACOMA-BALTHICA; HEAVY-METALS; INHERENT VARIABILITY; SCROBICULARIA-PLANA; REMARKABLE INVASION; AQUATIC ORGANISMS; INDICATOR; CADMIUM; POLLUTION AB Potamocorbula amurensis was assessed as a biosentinel species in San Francisco Bay, California, USA. Uptake of metal in both the laboratory and field showed that P. amurensis was sufficiently responsive to Ag, Cd, Cr, Ni and V to detect environmental differences in exposure; It was less suitable as an indicator of Cu and Zn contamination. Concentration factors for P. amurensis were: Ag, 386 000; Cd, 50 200; Cr, 36 600; Cu, 12 200; Ni, 5200; and Zn, 115 500. Samples were collected from 6 stations throughout the bay at near-monthly intervals from January 1991 to March 1992. Variability within a collection was influenced by gut content and animal size. Other sources of variability were time [coefficient of variation (CV) = 10 to 21%], small-scale spatial variability (within 3 km, CV = 10 to 25%), and large-scale spatial variability (CV = 3.3 to 12.4%). Depuration for 48 h was necessary to mitigate bias from gut content. Precision was improved by analyzing large numbers of individuals (60 to 120) separated into several (5 to 14) composites at each collection and by determining, from regression, the mean and variance for samples with significant correlations between metal concentration and shell length. Repeated monthly sampling increased the accuracy of long-term site characterizations. Temporal variability was small because of drought. The grand means of the concentrations of Ag, Cd, Cr, Ni, and V in the tissues of P. amurensis at each station for the 15 mo period revealed persistent contamination from industrialized Suisun Bay to the mouth of San Francisco Bay. Demonstration of responsiveness, precision and accuracy should be a prerequisite for the optimal use of biosentinels. RP BROWN, CL (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MAIL STOP 465, MENLO PK, CA 94025 USA. NR 53 TC 71 Z9 73 U1 0 U2 3 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD AUG PY 1995 VL 124 IS 1-3 BP 129 EP 142 DI 10.3354/meps124129 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA RW867 UT WOS:A1995RW86700011 ER PT J AU LIST, JH TERWINDT, JHJ AF LIST, JH TERWINDT, JHJ TI LARGE-SCALE COASTAL BEHAVIOR - INTRODUCTION SO MARINE GEOLOGY LA English DT Editorial Material C1 UNIV UTRECHT,INST MARINE & ATMOSPHER RES UTRECHT,NETHERLANDS CTR COASTAL RES,3508 TC UTRECHT,NETHERLANDS. RP LIST, JH (reprint author), US GEOL SURVEY,384 WOODS HOLE RD,WOODS HOLE,MA 02543, USA. NR 6 TC 9 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD AUG PY 1995 VL 126 IS 1-4 BP 1 EP 3 DI 10.1016/0025-3227(95)00062-4 PG 3 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA RY155 UT WOS:A1995RY15500001 ER PT J AU HEKINIAN, R STOFFERS, P AKERMAND, D BINARD, N FRANCHETEAU, J DEVEY, C GARBESCHONBERG, D AF HEKINIAN, R STOFFERS, P AKERMAND, D BINARD, N FRANCHETEAU, J DEVEY, C GARBESCHONBERG, D TI MAGMATIC EVOLUTION OF THE EASTER MICROPLATE-CROUGH SEAMOUNT REGION (SOUTH EAST PACIFIC) SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article DE PETROLOGY; STRUCTURE; VOLCANISM; MICROPLATE ID RARE-EARTH ELEMENTS; TECTONIC EVOLUTION; PLATE MOTIONS; MANTLE; BASALTS; VOLCANISM; ORIGIN; TRACE; RISE; PETROGENESIS AB The Easter microplate-Crough Seamount region located between 25 degrees S-116 degrees W and 25 degrees S-122 degrees W consists of a chain of seamounts forming isolated volcanoes and elongated (100-200 km in length) en echelon volcanic ridges oriented obliquely NE (N 065 degrees), to the present day general spreading direction (N 100 degrees) of the Pacific-Nazca plates. The extension of this seamount chain into the southwestern edge of the Easter microplate near 26 degrees 30' S-115 degrees W was surveyed and sampled. The southern boundary including the Orongo fracture zone and other shallow ridges (<2000 m high) bounding the Southwest Rift of the microplate consists of fault scarps where pillow lava, dolerite, and metabasalts are exposed. The degree of rock alternation inferred from palagonitization of glassy margins suggests that the volcanic ridges are as old as the shallow ridges bounding the Southwest Rift of the microplate. The volcanics found on the various structures west of the microplate consist of depleted (K/Ti<0.1), transitional (K/Ti=0.11-0.25) and enriched (K/Ti>0.25) MORBs which are similar in composition to other more recent basalts from the Southwest and East Rifts spreading axes of the Easter microplate. Incompatible element ratios normalized to chondrite values {(Ce/Yb)(N) = 1-2.5}, {(La/Sm)(N) = 0.4-1.2} and {(Zr/Y)(N) = 0.7-2.5} of the basalts are also similar to present day volcanism found in the Easter microplate. The volcanics from the Easter microplate-Crough region are unrelated to other known South Pacific intraplate magmatism (i.e, Society, Pitcairn, and Salas y Gomez Islands). Instead their range in incompatible element ratios is comparable to the submarine basalts from the recently investigated Ahu and Umu volcanic field (Easter hotspot) (Scientific Party SO80, 1993) and centered at about 80 km west of Easter Island. The oblique ridges and their associated seamounts are likely to represent ancient leaky transform faults created during the initial stage of the Easter microplate formation (approximate to 5 Ma), It appears that volcanic activity on seamounts overlying the oblique volcanic ridges has continued during their westward drift from the microplate as shown by the presence of relatively fresh lava observed on one of these structures, namely the first Oblique Volcanic Ridge near 25 degrees S-118 degrees W at about 160 km west of the Easter microplate West Rift. Based on a reconstruction of the Easter microplate, it is suggested that the Crough seamount (<800 m depth) was formed by earlier (7-10 Ma) hotspot magmatic activity which also created Easter Island. C1 CHRISTIAN ALBRECHTS UNIV KIEL,INST GEOL PALAONTOL,W-2300 KIEL,GERMANY. CHRISTIAN ALBRECHTS UNIV KIEL,INST MINERAL PETROG,W-2300 KIEL,GERMANY. US GEOL SURVEY,MENLO PK,CA 94025. UNIV BRETAGNE OCCIDENTALE,F-29287 BREST,FRANCE. RP HEKINIAN, R (reprint author), IFREMER,CTR BREST,BP 70,F-29263 PLOUZANE,FRANCE. RI Garbe-Schonberg, Dieter/E-2439-2016; Devey, Colin/I-3898-2016 OI Garbe-Schonberg, Dieter/0000-0001-9006-9463; Devey, Colin/0000-0002-0930-7274 NR 54 TC 14 Z9 14 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0025-3235 J9 MAR GEOPHYS RES JI Mar. Geophys. Res. PD AUG PY 1995 VL 17 IS 4 BP 375 EP 397 DI 10.1007/BF01227041 PG 23 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA RP093 UT WOS:A1995RP09300003 ER PT J AU HUGHES, JM FOORD, EE HUBBARD, MA NI, YX AF HUGHES, JM FOORD, EE HUBBARD, MA NI, YX TI THE CRYSTAL-STRUCTURE OF CHERALITE-(CE), (LREE, CA, TH, U) (P,SI)O-4, A MONAZITE-GROUP MINERAL SO NEUES JAHRBUCH FUR MINERALOGIE-MONATSHEFTE LA English DT Article DE CHERALITE; CRYSTAL STRUCTURE; MONAZITE AB Cheralite-(Ce), the title compound, is a monazite isostructure with stoichiometric Th4+; the phase is important because it is the natural analog of a proposed solid-state repository for radioactive actinides. The atomic arrangements of two samples of cheralite-(Ce), including material from the type locality, have been refined to R values of 0.022 and 0.024. The phase crystallizes in space group P2(1)/n, and no ordering of substituents causing a decrease in symmetry is noted. Like monazite, the atomic arrangement is formed of distorted, 9-coordinated REE (Th) polyhedra linked to P (Si) tetrahedra in [001] chains. Charge-balance for the REE(3+)<----> Th4+ substitution is maintained by concomitant substitutions of Ca2+ in the REE site and Si4+ for P5+ in the tetrahedral site. With the substitution of smaller constituents (Th-[9](4+) = 1.09 Angstrom and Ca-[9](2+) = 1.18 Angstrom for Ce-[9](3+) = 1.196 Angstrom) in the REE site, contraction of that site occurs principally along interchain equatorial bonds in (001). Intrachain bonds to the phosphate tetrahedra along [001] shorten to a lesser extent because the increased cation repulsion of the Th4+-P5+-Th4+ sequence in the cheralite-(Ce) chains, as opposed to the REE(3+)-P5+-REE(3+) sequence in monazite, hinders contraction of those bonds. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP HUGHES, JM (reprint author), MIAMI UNIV,DEPT GEOL,OXFORD,OH 45056, USA. NR 8 TC 5 Z9 5 U1 0 U2 9 PU E SCHWEIZERBART'SCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0028-3649 J9 NEUES JB MINER MONAT JI Neues Jahrb. Mineral.-Mon.hefte PD AUG PY 1995 IS 8 BP 344 EP 350 PG 7 WC Mineralogy SC Mineralogy GA TA066 UT WOS:A1995TA06600002 ER PT J AU SPIRAKIS, CS HEYL, AV AF SPIRAKIS, CS HEYL, AV TI EVALUATION OF PROPOSED PRECIPITATION MECHANISMS FOR MISSISSIPPI VALLEY-TYPE DEPOSITS SO ORE GEOLOGY REVIEWS LA English DT Review ID ROCK FLUORSPAR DISTRICT; THERMOCHEMICAL SULFATE REDUCTION; LEAD-ZINC DEPOSITS; FLUID INCLUSIONS; VIBURNUM-TREND; SOUTHEAST MISSOURI; ORE DEPOSITION; HYDROTHERMAL SYSTEMS; ISOTOPE SYSTEMATICS; THERMAL EVOLUTION AB The mechanism of precipitation is an important aspect of any genetic model for Mississippi Valley-type deposits. Yet most of the precipitation mechanisms for minerals in the Mississippi Valley-type association have serious flaws. Solution mixing would require an unlikely series of solutions to account for the various minerals in the ores, and it does not account for the universal occurrence of organic matter in the ores nor for the oxidation state of sulfur in pyrite in the ores. Sulfate reduction addresses some of these problems, but is inconsistent with kinetic data and could not be reversed to account for the oscillations between precipitation and dissolution of sulfide minerals in the ores. Carbon dioxide effervescence does not address the precipitation of most minerals in the ores, and all of the evidence for effervescence may be explained in other ways. Cooling of the mineralizing solution could precipitate many minerals, but fluid inclusion data suggest that, in many deposits, the solution did not cool significantly as any particular stage formed. A credible genetic model also must explain why all of the minerals precipitated at the same sites; any combination of the above mechanisms which suggests that unrelated mechanisms occurred at the same sites by coincidence is unlikely. The most reasonable scenario is that a hot, thiosulfate-bearing mineralizing solution reacted in various ways with organic matter at the sites of mineralization to precipitate the ore minerals. The organic matter acted as a reductant, source of carbon dioxide, source of organic acids, and a substrate for bacterial metabolism of thiosulfate in various stages of mineralization. Thus organic matter links all stages of the mineralization to the same sites. RP SPIRAKIS, CS (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 939,LAKEWOOD,CO 80225, USA. NR 78 TC 15 Z9 17 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-1368 J9 ORE GEOL REV JI Ore Geol. Rev. PD AUG PY 1995 VL 10 IS 1 BP 1 EP 17 DI 10.1016/0169-1368(95)00008-P PG 17 WC Geology; Mineralogy; Mining & Mineral Processing SC Geology; Mineralogy; Mining & Mineral Processing GA RX276 UT WOS:A1995RX27600001 ER PT J AU BENSON, L KASHGARIAN, M RUBIN, M AF BENSON, L KASHGARIAN, M RUBIN, M TI CARBONATE DEPOSITION, PYRAMID LAKE SUBBASIN, NEVADA .2. LAKE LEVELS AND POLAR-JET STREAM POSITIONS RECONSTRUCTED FROM RADIOCARBON AGES AND ELEVATIONS OF CARBONATES (TUFAS) DEPOSITED IN THE LAHONTAN BASIN SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY LA English DT Article ID GREAT-BASIN; PALEOCLIMATIC IMPLICATIONS; BONNEVILLE; CLIMATE; CACO3.6H2O; CHRONOLOGY; IKAITE; USA; BP AB Most of the tufas in the Pyramid Lake subbasin were deposited within the last 35,000 yr, including most of the mound tufas that border the existing lake. Many of the older tufas (>21,000 yr B.P.) contained in the mounds were formed in association with ground-water discharge. The radiocarbon (C-14) ages of the older tufas represent maximum estimates of the time of their formation. Lake Lahontan experienced large and abrupt rises in level at similar to 22,000, 15,000, and 11,000 yr B.P. and three abrupt recessions in level at similar to 16,000, 13,600, and 10,000 yr B.P. The lake-level rises that were initiated at similar to 23,500 and 15,500 yr B.P. are believed to indicate the passage of the polar jet stream over the Lahontan basin. During expansion of the Laurentide Ice Sheet, the jet stream moved south across the basin, and during the contraction of the Ice Sheet, the jet stream moved north across the basin. The bulk of the carbonate contained in the mound tufas was deposited during the last major lake cycle (similar to 23,500-12,000 yr B.P.), indicating that ground- and surface-water discharges increased at similar to 23,500 and decreased at similar to 12,000 yr B.P. A lake-level oscillation that occurred between 11,000 and 10,000 yr B.P. is represented by a 2-cm thick layer of dense laminated tufa that occurs at and below 1180 m in the low-elevation tufa mounds and at 1205 m in the Winnemucca Lake subbasin. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550. US GEOL SURVEY,RESTON,VA 22092. RP BENSON, L (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. RI Kashgarian, Michaele/E-1665-2011 OI Kashgarian, Michaele/0000-0001-7824-8418 NR 39 TC 74 Z9 75 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-0182 J9 PALAEOGEOGR PALAEOCL JI Paleogeogr. Paleoclimatol. Paleoecol. PD AUG PY 1995 VL 117 IS 1-2 BP 1 EP 30 DI 10.1016/0031-0182(94)00103-F PG 30 WC Geography, Physical; Geosciences, Multidisciplinary; Paleontology SC Physical Geography; Geology; Paleontology GA RV638 UT WOS:A1995RV63800001 ER PT J AU BRALOWER, TJ ZACHOS, JC THOMAS, E PARROW, M PAULL, CK KELLY, DC SILVA, IP SLITER, WV LOHMANN, KC AF BRALOWER, TJ ZACHOS, JC THOMAS, E PARROW, M PAULL, CK KELLY, DC SILVA, IP SLITER, WV LOHMANN, KC TI LATE PALEOCENE TO EOCENE PALEOCEANOGRAPHY OF THE EQUATORIAL PACIFIC-OCEAN - STABLE ISOTOPES RECORDED AT OCEAN DRILLING PROGRAM SITE-865, ALLISON-GUYOT SO PALEOCEANOGRAPHY LA English DT Article ID PLANKTONIC-FORAMINIFERA; SOUTH-ATLANTIC; MIDDLE EOCENE; BENTHIC FORAMINIFERA; SURFACE-TEMPERATURE; PALEOGENE; CIRCULATION; CLIMATE; MAGNETOBIOCHRONOLOGY; TERTIARY AB An expanded and largely complete upper Paleocene to upper Eocene section was recovered from the pelagic cap overlying Allison Guyot, Mid-Pacific Mountains at Ocean Drilling Program (ODP) Site 865 (18 degrees 26'N, 179 degrees 33'W; paleodepth 1300-1500 m). Reconstructions show that the site was within a few degrees of the equator during the Paleogene. Because no other Paleogene sections have been recovered in the Pacific Ocean at such a low latitude, Site 865 provides a unique record of equatorial Pacific paleoceanography. Detailed stable isotopic investigations were conducted on three planktonic foraminiferal taxa (species of Acarinina, Morozovella, and Subbotina). We studied benthic foraminiferal isotopes at much lower resolution on species of Cibicidoides and Lenticulina, Nuttallides truempyi and Gavelinella beccariiformis, because of their exceptional rarity. The delta(18)O and delta(13)C stratigraphies from Site 865 are generally similar to those derived from other Paleocene and Eocene sections. The planktonic foraminiferal records at Site 865, however, include significantly less short-term, single-sample variability than those from higher-latitude sites, indicating that this tropical, oligotrophic location had a comparatively stable water column structure with a deep mixed layer and less seasonal variability. Low-amplitude (0.1-0.8 parts per thousand) oscillations on timescales of 250,000 to 300,000 years correlate between the delta(13)C records of all planktonic taxa and may represent fluctuations in the mixing intensity of surface waters. Peak sea surface temperatures of 24 degrees-25 degrees C occurred in the earliest Eocene, followed by a rapid cooling of 3-6 degrees C in the late early Eocene. Temperatures remained cool and stable through the middle Eocene. In the late Eocene, surface water temperatures decreased further. Vertical temperature gradients decreased dramatically in the late Paleocene and were relatively constant through much of the Eocene but increased markedly in the late Eocene. Intermediate waters warmed through the late Paleocene, reaching a maximum temperature of 10 degrees C in the early Eocene. Cooling in the middle and late Eocene paralleled that of surface waters, with latest Eocene temperatures below 5 degrees C. Extinction patterns of benthic foraminifera in the latest Paleocene were similar to those observed at other Pacific sites and were coeval with a short-term, very rapid negative excursion in delta(13)C values in planktonic and benthic taxa as at other sites. During this excursion, benthic foraminiferal delta(18)O values decreased markedly, indicating warming of 4 to 6 degrees C for tropical intermediate waters, while planktonic taxa show slight warming (1 degrees C) followed by 2 degrees C of cooling. Convergence of delta(18)O values of planktonic and benthic foraminifera suggests that thermal gradients in the water column in this tropical location collapsed during the excursion. These data are consistent with the hypothesis that equatorial Pacific surface waters were a potential source of warm, higher salinity waters which filled portions of the deep ocean in the latest Paleocene. Oxygen isotopic data indicate that equator to high southern latitude sea surface thermal gradients decreased to as little as 4 degrees C at the peak of the excursion, suggesting some fundamental change in global heat transport. C1 UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. UNIV MILAN,DIPARTIMENTO SCI TERRA,I-20133 MILAN,ITALY. US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,MENLO PK,CA 94025. YALE UNIV,DEPT GEOL & GEOPHYS,NEW HAVEN,CT 06511. UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064. WESLEYAN UNIV,DEPT EARTH & ENVIRONM SCI,MIDDLETOWN,CT 06457. RP BRALOWER, TJ (reprint author), UNIV N CAROLINA,DEPT GEOL,CB 3315,CHAPEL HILL,NC 27599, USA. RI Zachos, James/A-7674-2008; Thomas, Ellen/E-5573-2011 OI Thomas, Ellen/0000-0002-7141-9904 NR 90 TC 150 Z9 154 U1 3 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD AUG PY 1995 VL 10 IS 4 BP 841 EP 865 DI 10.1029/95PA01143 PG 25 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA RM032 UT WOS:A1995RM03200010 ER PT J AU CARR, M AF CARR, M TI MARTIAN METEORITES REVEAL TORRID PAST SO PHYSICS WORLD LA English DT Article RP CARR, M (reprint author), US GEOL SURVEY,ASTROGEOL BRANCH,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8585 J9 PHYS WORLD JI Phys. World PD AUG PY 1995 VL 8 IS 8 BP 25 EP 26 PG 2 WC Physics, Multidisciplinary SC Physics GA RP762 UT WOS:A1995RP76200031 ER PT J AU LOVLEY, DR CHAPELLE, FH AF LOVLEY, DR CHAPELLE, FH TI DEEP SUBSURFACE MICROBIAL PROCESSES SO REVIEWS OF GEOPHYSICS LA English DT Review ID SULFATE-REDUCING BACTERIA; DISSOLVED INORGANIC CARBON; COASTAL-PLAIN SEDIMENTS; SAVANNAH RIVER PLANT; SOUTH-CAROLINA; ORGANIC-MATTER; GROUND-WATER; FE(III)-REDUCING BACTERIA; PHYSIOLOGICAL DIVERSITY; DENITRIFYING CONDITIONS AB Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron accepters just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H-2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of other habitats, the study of deep subsurface microbiology is still in its infancy. C1 US GEOL SURVEY,DIV WATER RESOURCES,COLUMBIA,SC 29210. RP LOVLEY, DR (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,430 NATL CTR,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. NR 122 TC 228 Z9 234 U1 10 U2 81 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD AUG PY 1995 VL 33 IS 3 BP 365 EP 381 DI 10.1029/95RG01305 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RJ301 UT WOS:A1995RJ30100003 ER PT J AU LEVY, DH SHOEMAKER, EM SHOEMAKER, CS AF LEVY, DH SHOEMAKER, EM SHOEMAKER, CS TI COMET - SHOEMAKER-LEVY-9 MEETS JUPITER SO SCIENTIFIC AMERICAN LA English DT Article C1 LOWELL OBSERV,FLAGSTAFF,AZ 86001. NO ARIZONA UNIV,FLAGSTAFF,AZ 86011. RP LEVY, DH (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 SN 0036-8733 J9 SCI AM JI Sci.Am. PD AUG PY 1995 VL 273 IS 2 BP 85 EP 91 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RK103 UT WOS:A1995RK10300036 ER PT J AU DIXON, TH ROBAUDO, S LEE, J REHEIS, MC AF DIXON, TH ROBAUDO, S LEE, J REHEIS, MC TI CONSTRAINTS ON PRESENT-DAY BASIN AND RANGE DEFORMATION FROM SPACE GEODESY SO TECTONICS LA English DT Article ID LATE QUATERNARY ACTIVITY; AMERICAN PLATE MOTION; WESTERN UNITED-STATES; SAN-ANDREAS FAULT; LINE INTERFEROMETRY; EASTERN CALIFORNIA; TRANSFORM FAULTS; OWENS-VALLEY; SHEAR ZONE; PROVINCE AB We use new space geodetic data from very long baseline interferometry and satellite laser ranging combined with other geodetic and geologic data to study contemporary deformation in the Basin and Range province of the western United States. Northwest motion of the central Sierra Nevada block relative to stable North America, a measure of integrated Basin and Range deformation, is 12.1+/-1.2 mm/yr oriented N38 degrees W+/-5 degrees (one standard error), in agreement with previous geological estimates within uncertainties. This velocity reflects both east-west extension concentrated in the eastern Basin and Range and north-northwest directed right lateral shear concentrated in the western Basin and Range. Fly, Nevada is moving west at 4.9+/-1.3 mm/yr relative to stable North America, consistent with dip-slip motion on the north striking Wasatch fault and other north striking normal faults. Comparison with ground-based geodetic data suggests that most of this motion is accommodated within similar to 50 lan of the Wasatch fault zone. Paleoseismic data for the Wasatch fault zone and slip rates based on seismic energy release in the region both suggest much lower slip rates. The discrepancy may be explained by some combination of additional deformation away from the Wasatch fault itself, aseismic slip, or a seismic rate that is anomalously low with respect to longer time averages. Deformation in the western Basin and Range province is also largely confined to a relatively narrow boundary zone and in our study area is partitioned into the eastern California shear zone, accommodating 10.7+/-1.6 mm/yr of north-northwest directed right-lateral shear, and a small component (similar to 1 mm/yr) of west-southwest - east-northeast extension. A slip rate budget for major strike-slip faults in our study area based on a combination of local geodetic or late Quaternary geologic data and the regional space geodetic data suggests the following rates of right-lateral slip: Owens Valley fault zone, 3.9+/-1.1 mm/yr; Death Valley-Furnace Creek fault zone, 3.3+/-2.2 mm/yr; White Mountains fault zone in northern Owens Valley, 3.4+/-1.2 mm/yr; Fish Lake Valley fault zone, 6.2+/-2.3 mm/yr. In the last few million years the locus of right-lateral shear in the region has shifted west and become more north trending as slip on the northwest striking Death Valley-Furnace Creek fault zone has decreased and is increasingly accommodated on the north-northwest striking Owens Valley fault zone. C1 CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125. US GEOL SURVEY,LAKEWOOD,CO 80225. RP DIXON, TH (reprint author), UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149, USA. NR 85 TC 143 Z9 143 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD AUG PY 1995 VL 14 IS 4 BP 755 EP 772 DI 10.1029/95TC00931 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RN833 UT WOS:A1995RN83300001 ER PT J AU GORDON, JD SCHRODER, LJ MORDENMOORE, AL BOWERSOX, VC AF GORDON, JD SCHRODER, LJ MORDENMOORE, AL BOWERSOX, VC TI THE STABILITY OF HYDROGEN-ION AND SPECIFIC CONDUCTANCE IN FILTERED WET-DEPOSITION SAMPLES STORED AT AMBIENT-TEMPERATURES SO WATER AIR AND SOIL POLLUTION LA English DT Article ID PRECIPITATION SAMPLES; PH AB Separate experiments by the U.S. Geological Survey (USGS) and the Illinois State Water Survey Central Analytical Laboratory (CAL) independently assessed the stability of hydrogen ion and specific conductance in filtered wet-deposition samples stored at ambient temperatures. The USGS experiment represented a test of sample stability under a diverse range of conditions, whereas the CAL experiment was a controlled test of sample stability. In the experiment by the USGS, a statistically significant (alpha = 0.05) relation between [H+] and time was found for the composited filtered, natural, wet-deposition solution when all reported values are included in the analysis. However, if two outlying pH values most likely representing measurement error are excluded from the analysis, the change in [H+] over time was not statistically significant. In the experiment by the CAL, randomly selected samples were reanalyzed between July 1984 and February 1991. The original analysis and reanalysis pairs revealed that [H+] differences, although very small, were statistically different from zero, whereas specific-conductance differences were not. Nevertheless, the results of the CAL reanalysis project indicate there appears to be no consistent, chemically significant degradation in sample integrity with regard to [H+] and specific conductance while samples are stored at room temperature at the CAL. Based on the results of the CAL and USGS studies, short-term (45-60 day) stability of [H+] and specific conductance in natural filtered wet-deposition samples that are shipped and stored unchilled at ambient temperatures was satisfactory. C1 ILLINOIS STATE WATER SURVEY,CENT ANALYT LAB,CHAMPAIGN,IL 61820. RP GORDON, JD (reprint author), US GEOL SURVEY,BOX 25046,MS 401,DENVER,CO 80225, USA. NR 19 TC 1 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD AUG PY 1995 VL 83 IS 3-4 BP 299 EP 313 DI 10.1007/BF00477359 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA RY462 UT WOS:A1995RY46200009 ER PT J AU KALKHOFF, SJ AF KALKHOFF, SJ TI RELATION BETWEEN STREAM-WATER QUALITY AND GEOHYDROLOGY DURING BASE-FLOW CONDITIONS, ROBERTS CREEK WATERSHED, CLAYTON COUNTY, IOWA SO WATER RESOURCES BULLETIN LA English DT Article DE WATER QUALITY; HYDROGEOLOGY; NONPOINT SOURCE POLLUTION; NITROGEN, KARST ID NITRATE; ATRAZINE; RIVER AB An investigation to determine the relation between stream water quality and geohydrology in the Roberts Creek watershed, Clayton County, Iowa, was conducted during selected baseflow periods in 1988-90. Discharge measurements were made and water samples collected for analyses of nutrients and selected herbicides in 19 subbasins along the main stem and tributaries of Roberts Creek. The areal extent of unconsolidated and bedrock units subcropping in each subbasin was quantified. The hydrologic data were correlated statistically with the geologic data to determine relations. Roberts Creek generally gained water and had larger nitrogen concentrations in subbasins in which loess and alluvial material were underlain primarily by low-permeability till and shale units. Roberts Creek generally lost water and had lower nitrate concentrations in subbasins with subcropping karstic units. Nitrogen concentrations decreased in streams underlain by the karstic units because the nitrogen removed by biological processes was not replaced by ground-water inflow. Seepage from Roberts Creek to ground water in areas of subcropping karstic carbonate rocks reduced the flow, which reduced the velocity, causing increased residence time of water in the stream. The additional residence time may allow additional time for biological processes to remove nitrogen from solution. There was no significant relation between dissolved orthophosphate or atrazine and the underlying geology. RP KALKHOFF, SJ (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,BOX 1230,IOWA CITY,IA 52244, USA. OI Kalkhoff, Stephen/0000-0003-4110-1716 NR 36 TC 8 Z9 8 U1 0 U2 2 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD AUG PY 1995 VL 31 IS 4 BP 593 EP 604 PG 12 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RP305 UT WOS:A1995RP30500005 ER PT J AU SCHMIDT, JC GRAMS, PE WEBB, RH AF SCHMIDT, JC GRAMS, PE WEBB, RH TI COMPARISON OF THE MAGNITUDE OF EROSION ALONG 2 LARGE REGULATED RIVERS SO WATER RESOURCES BULLETIN LA English DT Article DE COLORADO RIVER; DAMS; EROSION; GEOMORPHOLOGY; GRAND CANYON; HELLS CANYON; SNAKE RIVER ID GRAND-CANYON; RECIRCULATING FLOW; COLORADO RIVER; SEDIMENTATION; EVOLUTION; ARIZONA AB Historical inventories of sand bar number and area are sufficient to detect large-scale differences in geomorphic adjustment among regulated rivers that flow through canyons with abundant debris fans. In these canyons, bedrock and large boulders create constrictions and expansions, and alluvial bars occur in associated eddies at predictable sites. Although these bars may fluctuate considerably in size, the locations of these bars rarely change, and their characteristics can be compared through time and among rivers. The area of sand bars exposed at low discharge in Hells Canyon has decreased 50 percent since dam closure, and most of the erosion occurred in the first nine years after dam closure. The number and size of sand bars in Grand Canyon downstream from Glen Canyon Dam have decreased much less; the number of sand bars decreased by 40 percent in some 8.3-km reaches, but by less than 20 percent elsewhere. These differences are in part related to the fact that flood regulation is much greater in Grand Canyon than in Hells Canyon, and that downstream tributaries resupply sediment to Grand Canyon but not to most of Hells Canyon. C1 UTAH STATE UNIV,DEPT GEOL,LOGAN,UT 84322. US GEOL SURVEY,WRD,TUCSON,AZ 85745. RP SCHMIDT, JC (reprint author), UTAH STATE UNIV,DEPT GEOG & EARTH RESOURCES,LOGAN,UT 84322, USA. NR 29 TC 21 Z9 21 U1 1 U2 4 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD AUG PY 1995 VL 31 IS 4 BP 617 EP 631 PG 15 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RP305 UT WOS:A1995RP30500007 ER PT J AU GELLIS, AC CHEAMA, A LAAHTY, V LALIO, S AF GELLIS, AC CHEAMA, A LAAHTY, V LALIO, S TI ASSESSMENT OF GULLY-CONTROL STRUCTURES IN THE RIO-NUTRIA WATERSHED, ZUNI RESERVATION, NEW-MEXICO SO WATER RESOURCES BULLETIN LA English DT Article DE EROSION; GULLY; WATERSHED REHABILITATION; EROSION CONTROL ID COLORADO; BASIN AB During the latter part of the 19th century and the early part of the 20th century, a major cycle of erosion, arroyo cutting, and gullying occurred in the southwestern United States. Since this erosion cycle began, many projects to control erosion, such as the Civilian Conservation Corps projects in the 1930s, were initiated. However, in the Southwestern United States few studies have documented the effect of these structures in reducing erosion or their effect on gully systems. As part of a watershed rehabilitation project on the Zuni Reservation, New Mexico, 47 structures made either of earth or rocks and 23 rock and brush structures were assessed. Sixty percent of the 47 earth or rock structures have breached and relative to dam height, 65 percent of 47 structures are more than 50 percent silted. Of the 23 rock and brush structures, 22 percent have breached or are close to breaching. Reasons for breaching of all structural types may be piping, scour immediately below the structures, large runoff and large drainage area, poor maintenance, headcutting, and active arroyo deepening and widening. In most cases, documentation does not exist on structure design, the specific purpose for a structure, or when these structures were built. C1 PUEBLO ZUNI,ZUNI,NM 87327. RP GELLIS, AC (reprint author), US GEOL SURVEY,4501 INDIAN SCH RD NE,NO 200,ALBUQUERQUE,NM 87110, USA. NR 27 TC 11 Z9 11 U1 3 U2 8 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD AUG PY 1995 VL 31 IS 4 BP 633 EP 646 PG 14 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RP305 UT WOS:A1995RP30500008 ER PT J AU BELITZ, K PHILLIPS, SP AF BELITZ, K PHILLIPS, SP TI ALTERNATIVE TO AGRICULTURAL DRAINS IN CALIFORNIA SAN-JOAQUIN VALLEY - RESULTS OF A REGIONAL-SCALE HYDROGEOLOGIC APPROACH SO WATER RESOURCES RESEARCH LA English DT Article ID GROUNDWATER-FLOW; KESTERSON RESERVOIR; SHALLOW GROUNDWATER; SOLUTE MOVEMENT; IRRIGATION; CONTAMINATION; SELENIUM; LATERALS; MOBILITY; SALINITY AB The occurrence of selenium in agricultural drainage water derived from the central part of the western San Joaquin Valley has focused concern on alternatives to agricultural drains for managing shallow, poor-quality groundwater. A transient, three-dimensional simulation model was developed to evaluate the response of the water table to alternatives that affect recharge to or discharge from the groundwater flow system. The modeled area is 551 mi(2) (1 mi(2) = 2.59 km(2)) and includes both the semiconfined and confined zones above and below the Corcoran Clay Member of the Tulare Formation of Pleistocene age. The simulation model was calibrated using hydrologic data from 1972 to 1988, and was extended to the year 2040 to forecast for various management alternatives, including maintenance of present practices, land retirement, reduced recharge, increased groundwater pumping, and combinations of these alternatives. Maintenance of present practices results in a worsening of the situation: the total area subject to bare-soil evaporation increases from 224 mi(2) in 1990 to 344 mi(2) in 2040, and drain flow increases from 25,000 ac ft/yr (1 ac ft = 1234 m(3)) to 28,000 ac ft/yr. Although land retirement results in elimination of bare-soil evaporation and drain flow in the areas retired, it has little to no effect in adjacent areas. In contrast, regional-scale changes in recharge and pumping are effective for regional management. The area subject to bare-soil evaporation can be reduced to 78 mi(2), and drain flow to 8000 ac ft/yr if (1) recharge is reduced by 15% (26,009 ac ft/yr) in areas that currently use surface and groundwater (362 mi(2)); (2) recharge is reduced by 40% (28,000 ac ft/yr) in areas that currently use only surface water (137 mi(2)); and (3) pumping rates are uniformly incremented by 0.5 ft/yr (160,000 ac ft/yr) in both areas. If these water budget changes were to be implemented in the study area, and in adjacent areas with similiar hydrogeologic characteristics, then approximately 400,000 ac ft/yr of surface water would be made available. Thus a shift in the hydrologic budget in the central part of the western San Joaquin Valley improves the prospects for sustaining agriculture in the area, and could provide substantial water resources for other uses. C1 US GEOL SURVEY,DIV WATER RESOURCES,SACRAMENTO,CA 95825. RP BELITZ, K (reprint author), DARTMOUTH COLL,FAIRCHILD SCI CTR,DEPT EARTH SCI,HANOVER,NH 03755, USA. NR 63 TC 17 Z9 17 U1 2 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1995 VL 31 IS 8 BP 1845 EP 1862 DI 10.1029/95WR01328 PG 18 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RM644 UT WOS:A1995RM64400003 ER PT J AU WOLOCK, DM AF WOLOCK, DM TI EFFECTS OF SUBBASIN SIZE ON TOPOGRAPHIC CHARACTERISTICS AND SIMULATED FLOW PATHS IN SLEEPERS RIVER WATERSHED, VERMONT SO WATER RESOURCES RESEARCH LA English DT Article ID NEW-YORK; CATCHMENT; SOIL; SCALE; RUNOFF; MODEL; CHEMISTRY AB The effects of subbasin size on topographic characteristics and simulated flow paths were determined for the 111.5-km(2) Sleepers River Research Watershed in Vermont using the watershed model TOPMODEL. Topography is parameterized in TOPMODEL as the spatial and statistical distribution of the index ln (a/tan B), where In is the Napierian logarithm, a is the upslope area per unit contour length, and tan B is the slope gradient. The mean, variance, and skew of the ln (a/tan B) distribution were computed for several sets of nested subbasins (0.05 to 111.5 km(2)) along streams in the watershed and used as input to TOPMODEL. In general, the statistics of the ln (a/tan B) distribution and the simulated percentage of overland flow in total streamflow increased rapidly for some nested subbasins and decreased rapidly for others as subbasin size increased from 0.05 to 1 km(2), generally increased up to a subbasin size of 5 km(2), and remained relatively constant at a subbasin size greater than 5 km(2). Differences in simulated flow paths among subbasins of all sizes (0.05 to 111.5 km(2)) were caused by differences in the statistics of the ln (a/tan B) distribution, not by differences in the explicit spatial arrangement of ln (a/tan B) values within the subbasins. Analysis of streamflow chemistry data from the Neversink River watershed in southeastern New York supports the hypothesis that subbasin size affects flow-path characteristics. RP WOLOCK, DM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. NR 35 TC 22 Z9 26 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1995 VL 31 IS 8 BP 1989 EP 1997 DI 10.1029/95WR01183 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RM644 UT WOS:A1995RM64400014 ER PT J AU NELSON, JM SHREVE, RL MCLEAN, SR DRAKE, TG AF NELSON, JM SHREVE, RL MCLEAN, SR DRAKE, TG TI ROLE OF NEAR-BED TURBULENCE STRUCTURE IN BED-LOAD TRANSPORT AND BED FORM MECHANICS SO WATER RESOURCES RESEARCH LA English DT Article ID BOUNDARY-LAYER; FLOW; SEDIMENT; FLUME; MODEL AB The interactions between turbulence events and sediment motions during bed load transport were studied by means of laser-Doppler velocimetry and high-speed cinematography. Sweeps (u' > 0, w' < 0), which contribute positively to the mean bed shear stress, collectively move the majority of the sediment; primarily because they are extremely common. Outward interactions (u' > 0, w' > 0), which contribute negatively to the bed shear stress and are relatively rare, individually move as much sediment as sweeps of comparable magnitude and duration, however, and much more than bursts (u' < 0, w' > 0) and inward interactions (u' < 0, w' < 0). When the magnitude of the outward interactions increases relative to the other events, therefore, the sediment flux increases even though the bed shear stress decreases. Thus, although bed shear stress can be used to estimate bed load transport by flows with well-developed boundary layers, in which the flow is steady and uniform and the turbulence statistics all scale with the shear velocity, it is not accurate for flows with developing boundary layers, such as those over sufficiently nonuniform topography or roughness, in which significant spatial variations in the magnitudes and durations of the sweeps, bursts, outward interactions, and inward interactions occur. These variations produce significant peaks in bed load transport downstream of separation points, thus supporting the hypothesis that flow separation plays a significant role in the development of bed forms. C1 N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695. UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90095. UNIV CALIF SANTA BARBARA,DEPT MECH & ENVIRONM ENGN,OCEAN ENGN LAB,SANTA BARBARA,CA 93106. RP NELSON, JM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,NATL RES PROGRAM,DENVER FED CTR,MS 413,POB 25045,LAKEWOOD,CO 80225, USA. NR 37 TC 247 Z9 249 U1 4 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG PY 1995 VL 31 IS 8 BP 2071 EP 2086 DI 10.1029/95WR00976 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RM644 UT WOS:A1995RM64400022 ER PT J AU SCHWARZBACH, SE AF SCHWARZBACH, SE TI OZONE DEPLETION - CFC ALTERNATIVES UNDER A CLOUD SO NATURE LA English DT Editorial Material RP SCHWARZBACH, SE (reprint author), US FISH & WILDLIFE SERV,SACRAMENTO FIELD OFF,2800 COTTAGE WAY,ROOM E-1803,SACRAMENTO,CA 95825, USA. NR 9 TC 20 Z9 21 U1 0 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JUL 27 PY 1995 VL 376 IS 6538 BP 297 EP 298 DI 10.1038/376297a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RL443 UT WOS:A1995RL44300027 ER PT J AU LICHTE, FE AF LICHTE, FE TI DETERMINATION OF ELEMENTAL CONTENT OF ROCKS BY LASER-ABLATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY SO ANALYTICAL CHEMISTRY LA English DT Article ID RARE-EARTH ELEMENTS; GEOLOGICAL-MATERIALS; ICP-MS; ARGON AB Anew method of analysis for rocks and soils is presented using laser ablation inductively coupled plasma mass spectrometry. It is based on a lithium berate fusion and the free-running mode of a Nd/YAG laser. An Ar/N-2 sample gas improves sensitivity 7 x for most elements. Sixty-three elements are characterized for the fusion, and 49 elements can be quantified. Internal standards and isotopic spikes ensure accurate results. Limits of detection are 0.01 mu g/g for many trace elements. Accuracy approaches 5% for all elements. A new quality assurance procedure is presented that uses fundamental parameters to test relative response factors for the calibration. RP LICHTE, FE (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,MS 973,DENVER,CO 80225, USA. NR 26 TC 46 Z9 48 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUL 15 PY 1995 VL 67 IS 14 BP 2479 EP 2485 DI 10.1021/ac00110a024 PG 7 WC Chemistry, Analytical SC Chemistry GA RJ072 UT WOS:A1995RJ07200024 ER PT J AU HAUKSSON, E JONES, LM HUTTON, K AF HAUKSSON, E JONES, LM HUTTON, K TI THE 1994 NORTHRIDGE EARTHQUAKE SEQUENCE IN CALIFORNIA - SEISMOLOGICAL AND TECTONIC ASPECTS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WHITTIER-NARROWS EARTHQUAKE; SAN-FERNANDO EARTHQUAKE; OAK-RIDGE FAULT; SOUTHERN-CALIFORNIA; TRANSVERSE-RANGES; GEODETIC MEASUREMENT; FOCAL MECHANISMS; VENTURA-BASIN; LOS-ANGELES; DEFORMATION AB The M(W) 6.7 Northridge earthquake occurred on January 17, 1994, beneath the San Fernando Valley. Two seismicity clusters, located 25 km to the south and 35 km to the north-northwest, preceded the mainshock by 7 days and 16 hours, respectively. The mainshock hypocenter was relatively deep, at 19 km depth in the lower crust. It: had a thrust faulting focal mechanism with a rake of 100 degrees on a fault plane dipping 35 degrees to the south-southwest and striking N75 degrees W. Because the mainshock did not rupture the surface, its association with surficial geological features remains difficult to resolve. Nonetheless, its occurrence reemphasized the seismic hazard of concealed faults associated with the contractional deformation of the Transverse Ranges, The Northridge earthquake is part of the temporal increase in earthquake activity in the Los Angeles area since 1970, The mainshock was followed by an energetic aftershock sequence, Eight aftershocks of M greater than or equal to 5.0 and 48 aftershocks of 4 less than or equal to M < 5 occurred between January 17 and September 30, 1994. The aftershocks extend over most of the western San Fernando Valley and Santa Susana Mountains. They form a diffuse spatial distribution around the mainshock rupture plane, illuminating a previously unmapped thrust ramp, extending from 7-10 km depth into the lower crust to a depth of 23 km. No flattening of the aftershock distribution is observed near its bottom. At shallow depths, above 7-10 km, the thrust ramp is topped by a dense distribution of aftershock hypocenters bounded by some of the surficial faults. The dip of the ramp increases from east to west. The west side of the aftershock zone is characterized by a dense, steeply dipping, and north-northeast striking planar cluster of aftershocks that exhibited mostly thrust faulting. These events coincided with the Gillibrand Canyon! lateral ramp, along the ease side of the aftershock zone the aftershocks also exhibited primarily thrust faulting focal mechanisms. The focal mechanisms of;the aftershocks were dominated by thrust faulting in the large aftershocks, with some strike-slip and normal faulting in the smaller aftershocks. The 1971 San Fernando and the 1994 Northridge earthquakes ruptured partially abutting fault surfaces on opposite sides of a ridge. Both earthquakes accommodated north-south contractional deformation of the Transverse Ranges. The two earthquakes differ primarily in the dip direction of she faults and the depth of faulting. The 1971 north-northeast trend of left-lateral faulting (Chatsworth trend) was not activated in 1994. C1 US GEOL SURVEY, PASADENA, CA 91106 USA. RP HAUKSSON, E (reprint author), CALTECH, DIV GEOL & PLANETARY SCI, SEISMOL LAB, PASADENA, CA 91125 USA. NR 42 TC 107 Z9 108 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12335 EP 12355 DI 10.1029/95JB00865 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200001 ER PT J AU SOREY, ML FARRAR, CD MARSHALL, GA HOWLE, JF AF SOREY, ML FARRAR, CD MARSHALL, GA HOWLE, JF TI EFFECTS OF GEOTHERMAL DEVELOPMENT ON DEFORMATION IN THE LONG VALLEY-CALDERA, EASTERN CALIFORNIA, 1985-1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article AB Long Valley caldera in east central California has been the site of crustal unrest in the form of seismicity and ground deformation in response to magmatic inflation since 1980. Uplift of the resurgent dome has totaled similar to 0.6 m over the 1975-1992 period. Within this region of uplift, and near the southwestern edge of the resurgent dome, is the Casa Diablo area, which experienced relative subsidence of 0.17 m between 1985 and 1992. Geothermal fluid production began at Casa Diablo in 1985 to supply a binary electric power plant; currently, three such plants generate a total of about 40 MW of electricity. The plants are supplied by 170 degrees C water pumped from depths near 150 m; all the produced water is reinjected at cooler temperatures at depths near 600 m. Analyses of data from (1) regional leveling lines and a network of bench marks in the geothermal well field area, (2) tilt observations from an L-shaped array of bench marks, and (3) calculations relating pressure and temperature changes to subsidence indicate that relative subsidence at Casa Diablo results mainly from reductions in pressure in the shallow production reservoir and overlying formations and reductions in temperature in the underlying injection reservoir. Secondary effects on deformation are caused by offsets along the Taylor-Bryant fault bounding the west side of the well field. C1 US GEOL SURVEY, CARNELIAN BAY, CA 96140 USA. RP SOREY, ML (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 25 TC 10 Z9 10 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12475 EP 12486 DI 10.1029/95JB00955 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200012 ER PT J AU LANGBEIN, J DZURISIN, D MARSHALL, G STEIN, R RUNDLE, J AF LANGBEIN, J DZURISIN, D MARSHALL, G STEIN, R RUNDLE, J TI SHALLOW AND PERIPHERAL VOLCANIC SOURCES OF INFLATION REVEALED BY MODELING 2-COLOR GEODIMETER AND LEVELING DATA FROM LONG-VALLEY CALDERA, CALIFORNIA, 1988-1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EASTERN CALIFORNIA; 2-COLOR GEODIMETER; DEFORMATION; EARTHQUAKE AB We refined the model for inflation of the Long Valley caldera near Mammoth Lakes, California, by combining both geodetic measurements of baseline length and elevation changes. Baseline length changes measured using a two-color geodimeter with submillimeter precision revealed that the resurgent dome started to reinflate in late 1989. Measurements between late 1989 and mid-1992 revealed nearly 13 cm of extension across the resurgent dome. Geodetic leveling surveys with approximately 2-mm precision made in late 1988 and in mid-1992 revealed a maximum of about 8 cm of uplift of the resurgent dome. Two ellipsoidal sources satisfy both the leveling and two-color measurements, whereas spherical point sources could not. The model's primary inflation source is located 5.5 km beneath the resurgent dome with the two horizontal axes being nearly equal in size and the vertical axis being 4 times the length of the horizontal axes. A second ellipsoidal source was added to improve the fit to the two-color measurements. This secondary source is located at a depth between 10 and 20 km beneath the south moat of the caldera and has the geometry of an elongated ellipsoid or pipe that dips down to the northeast. In addition, the leveling data suggest dike intrusion beneath Mammoth Mountain during the 1988-1992 interval, which is likely associated with an intense swarm of small earthquakes during the summer of 1989 at that location. Our analysis shows the dike intrusion to be the shallowest of the three sources with a depth range of 1-3 km below the surface to the top of the intrusion. C1 US GEOL SURVEY, VANCOUVER, WA 98661 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP LANGBEIN, J (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 17 TC 72 Z9 72 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12487 EP 12495 DI 10.1029/95JB01052 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200013 ER PT J AU HARBERT, W HILLHOUSE, J VALLIER, T AF HARBERT, W HILLHOUSE, J VALLIER, T TI PALEOMAGNETISM OF THE PERMIAN WALLOWA TERRANE - IMPLICATIONS FOR TERRANE MIGRATION AND OROGENY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID APPARENT POLAR WANDER; NORTH-AMERICA; COLORADO PLATEAU; JURASSIC PLUTONS; OREGON; POLES; WRANGELLIA; ROTATION; DISPLACEMENT; ALASKA AB A sequence of volcaniclastic sedimentary and pyroclastic rocks of Permian age (late Leonardian or early Guadalupian; approximate to 260 Ma) in the Wallowa terrane of Oregon and Idaho has been sampled for paleomagnetic study. Forty-six sites (222 cores) were collected from folded, laminated siltstone, mudstone, and tuffaceous sandstone beds exposed along the Snake River in Hells Canyon. Several stratigraphic sections, within the 1500- to 2500-m-thick Hunsaker Creek Formation, were sampled over a stratigraphic interval of about 700 m. Thermal demagnetization revealed three components of magnetization. The A component has the lowest unblocking temperatures (generally less than about 200 degrees C), has normal polarity, and fails the fold test. The B component is removed between heating steps of about 200 degrees C and 550 degrees C, is of normal polarity, and also fails the fold test. The C component, observed between heating steps of approximately 550 degrees C and 660 degrees C, is always of negative inclination. The grouping of this component improves slightly upon unfolding, with the optimum grouping occurring at 95% unfolding, using sites with n greater than or equal to 3 and k greater than or equal to 10, (k(95)/k(0)=1.18), or 100% using sites n greater than or equal to 3 (k(95)/k(0)=1.51). This component is interpreted as the characteristic remanent ma,magnetization acquired during deposition of the Hunsaker Creek Formation based on the following observations: The better grouping of the high-temperature magnetic component after unfolding and the consistent reversed polarity seen in samples from the different sections. The resulting paleolatitude, calculated using inclination-only statistics, of 24 degrees +/- 12 degrees N (n greater than or equal to 3, k greater than or equal to 10), or 26 degrees +/- 9 degrees N (n greater than or equal to 3 sites), implies a northern hemisphere position of the Wallowa terrane during the Early Permian and possible southward transport of this terrane with respect to North America. If the Wallowa terrane was attached to the Wrangellia superterrane, our result indicates a northern hemisphere location for that superterrane during the Permian. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP HARBERT, W (reprint author), UNIV PITTSBURGH, DEPT GEOL & PLANETARY SCI, 321 OLD ENGN HALL, PITTSBURGH, PA 15260 USA. RI Harbert, William/E-3502-2010 NR 45 TC 6 Z9 6 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12573 EP 12588 DI 10.1029/94JB02129 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200018 ER PT J AU ANDREASSEN, K HART, PE GRANTZ, A AF ANDREASSEN, K HART, PE GRANTZ, A TI SEISMIC STUDIES OF A BOTTOM SIMULATING REFLECTION RELATED TO GAS HYDRATE BENEATH THE CONTINENTAL-MARGIN OF THE BEAUFORT SEA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MARINE-SEDIMENTS; METHANE HYDRATE; SOUND-VELOCITY; ROCKS; ZONE; COEFFICIENTS; RESERVOIR; BASE; WAVE AB The upper continental margin of the Beaufort Sea, north of Alaska, is underlain by a strong bottom simulating reflection (BSR) that lies 300 to 700 m beneath the seafloor and corresponds to the phase boundary between interstitial water and natural gas below and solid gas hydrate above. BSRs of similar origin are common worldwide, where they are usually interpreted to mark the base of gas hydrate-bearing elastic sediment, with or without underlying free gas in the sediment. Surprisingly little is known about the origin of these strong reflections. In this paper we analyze the contrasting physical properties which produce BSRs by comparing synthetic BSR amplitudes and waveforms for varying source-receiver offsets with multichannel seismic reflection data across the well-developed BSR of the Beaufort Sea. In order to discriminate whether free gas is present under the BSR or not, it was necessary to supplement near-vertical incidence data with prestack offset data. The amplitude-versus-offset (AVO) analysis indicates that the BSR is produced mainly by the existence of free gas in the elastic sediments beneath the BSR. The zone of free gas is, based on vertical incidence synthetics, estimated to be thinner than 11-16 m. It is possibly thicker than 16 m if the gas concentration decreases with depth. Saturation of gas hydrate in the sediment above the BSR is tentatively estimated from the AVO modeling to be less than 10% of the pore volume. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP ANDREASSEN, K (reprint author), UNIV TROMSO, INST BIOL & GEOL, N-9037 TROMSO, NORWAY. NR 54 TC 70 Z9 77 U1 2 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12659 EP 12673 DI 10.1029/95JB00961 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200023 ER PT J AU SAVAGE, JC AF SAVAGE, JC TI PRINCIPAL COMPONENT ANALYSIS OF INTERSEISMIC DEFORMATION IN SOUTHERN CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article AB Eight trilateration networks along the San Andreas fault in southern California have been surveyed repeatedly (8 to 19 times) within an approximately 15-year interval between 1971 and 1992. The data for each network were analyzed by principal component analysis to represent the observed changes in line length as a superposition of individual modes: L(ij) - L(i) = Sigma(k) A(ik)C(k)(t(j)), where L(ij) is the length of the ith line measured at the time t(j), L(i) is the average length of the ith line, and A(ik)C(k)(t(j)) is the kth mode. Each mode is described by a common time function C-k(t(j)) that is evaluated only at the times t(j) of the surveys, and the participation of each line in that mode is described by a constant amplitude A(ik), for that line. For all networks the deformation is largely described by the first mode, and the first-mode time function is essentially linear in time. That is, the deformation in each of the networks appears to be steady. Two anomalies in the accumulation of deformation were observed: In the network near Palmdale a transient strain event occurred in the second mode in early 1982, and in the network within Cajon Pass, fluctuations in the accumulation of deformation somewhat greater than would be attributed to measurement error were found. Although both anomalies are formally significant given the estimated measurement error, I am not confident that either anomaly is real. The principal conclusion is that the accumulation of interseismic deformation in the southern California trilateration networks is steady within the precision of measurement. RP SAVAGE, JC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS-977, MENLO PK, CA 94025 USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12691 EP 12701 DI 10.1029/95JB01155 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200025 ER PT J AU SAVAGE, JC LISOWSKI, M AF SAVAGE, JC LISOWSKI, M TI INTERSEISMIC DEFORMATION ALONG THE SAN-ANDREAS FAULT IN SOUTHERN CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID IMPERIAL-VALLEY EARTHQUAKE; STRESS REDISTRIBUTION; STRAIN ACCUMULATION; SLOW EARTHQUAKES; MOTION; GRAVITY; UPLIFT; MODEL AB Eight trilateration networks located along the San Andreas fault in southern California have been surveyed 8 to 19 times within a 14- to 17-year interval between 1971 and 1992. The data, measurements of distances between the same 10 to 32 pairs of geodetic monuments within a network in each of the surveys, have been corrected for coseismic offsets from nearby earthquakes calculated from dislocation models. The corrected data, a total of 2027 measurements, are displayed in the form of plots of measured distance versus time for each of the 167 lines measured. The hypothesis that the interseismic deformation is steady is tested by examining whether deviations from linear fits to the data in the plots are within the range expected for observational error. A significant deviation from steady deformation is found only for the network located near Palmdale, California. In that network, many of the measurements made in the survey of early 1982 deviate from the trend defined by the measurements in other surveys. The deviations are not of the form (fixed proportional error) one would generally expect from systematic survey error. If the survey of early 1982 is excluded, the remaining data at Palmdale are consistent-with steady deformation. Thus the apparent strain event observed near Palmdale in 1982 was transient. RP SAVAGE, JC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS-977, MENLO PK, CA 94025 USA. NR 30 TC 18 Z9 19 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12703 EP 12717 DI 10.1029/95JB01153 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200026 ER PT J AU JACHENS, RC GRISCOM, A ROBERTS, CW AF JACHENS, RC GRISCOM, A ROBERTS, CW TI REGIONAL EXTENT OF GREAT-VALLEY BASEMENT WEST OF THE GREAT-VALLEY, CALIFORNIA - IMPLICATIONS FOR EXTENSIVE TECTONIC WEDGING IN THE CALIFORNIA COAST RANGES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID NORTHERN CALIFORNIA; CRUSTAL STRUCTURE; FAULT; OPHIOLITE; SEISMOTECTONICS; BLUESCHISTS; SELDOVIA; ALASKA; THRUST; DIABLO AB Interpretation and modeling of the magnetic field of central California indicate that the magnetic basement of the forearc deposits of the Great Valley sequence extends westward beneath the coeval subduction-related rocks of the Franciscan Complex. The basement surface slopes gently to the west, reaching midcrustal depths (15-19 km) at distances of 50-100 km west of the Great Valley. This magnetic basement is disrupted by the Hayward-Rodgers Creek Fault system and is cut by the San Andreas Fault at the south end of the Great Valley and possibly throughout much of central California. The widespread presence of the Great Valley basement beneath rocks of the Franciscan Complex implies that the basement is more extensive than proposed in earlier interpretations based on seismic studies near the Franciscan Complex-Great Valley sequence contact. This result forces major modifications to ideas concerning this fossil subduction complex and other subduction zones. The eastern boundary fault of the Franciscan Complex (Coast Range Fault) is not (and never was) a subduction zone thrust fault but rather was originally a roof thrust (wedge-roof fault) formed above the eastward wedging mass of Franciscan Complex intruded along the top of the basement beneath the Great Valley deposits. This tectonic interpretation offers a solution for the question of how high-pressure metamorphic rocks of the Franciscan Complex were juxtaposed at the Coast Range Fault against low-pressure metamorphic rocks of the Great Valley sequence. This interpretation also implies an older flat-lying thrust fault (wedge-floor fault) that forms the top of magnetic basement between the active San Andreas and Hayward Faults at depths of 15-17 km. This older thrust fault may today transfer strain between the two young strike-slip faults, possibly explaining the apparent coupling of major nineteenth century earthquakes on these two faults. The former east dipping subduction zone along which the rocks of the Franciscan Complex accumulated must lie west of the western limit of the Great Valley magnetic basement. RP JACHENS, RC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 54 TC 37 Z9 38 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12769 EP 12790 DI 10.1029/95JB00718 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200030 ER PT J AU HICKMAN, S SIBSON, R BRUHN, R AF HICKMAN, S SIBSON, R BRUHN, R TI INTRODUCTION TO SPECIAL SECTION - MECHANICAL INVOLVEMENT OF FLUIDS IN FAULTING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID SAN-ANDREAS FAULT; HEAT-FLOW; ACCRETIONARY PRISMS; RUPTURE NUCLEATION; PRESSURE SOLUTION; THRUST BELTS; NEW-ZEALAND; VAL-DOR; EARTHQUAKES; STRESS C1 UNIV UTAH, DEPT GEOL & GEOPHYS, SALT LAKE CITY, UT 84112 USA. UNIV OTAGO, DEPT GEOL, DUNEDIN, NEW ZEALAND. RP HICKMAN, S (reprint author), US GEOL SURVEY, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 109 TC 259 Z9 277 U1 1 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12831 EP 12840 DI 10.1029/95JB01121 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200033 ER PT J AU EBERHARTPHILLIPS, D STANLEY, WD RODRIGUEZ, BD LUTTER, WJ AF EBERHARTPHILLIPS, D STANLEY, WD RODRIGUEZ, BD LUTTER, WJ TI SURFACE SEISMIC AND ELECTRICAL METHODS TO DETECT FLUIDS RELATED TO FAULTING SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID SAN-ANDREAS FAULT; SELF-POTENTIAL ANOMALIES; SATURATED CRACKED SOLIDS; LOMA-PRIETA EARTHQUAKE; CLAY CONTENT; COMPRESSIONAL WAVES; CENTRAL CALIFORNIA; VELOCITY STRUCTURE; ZONE; ATTENUATION AB In the absence of drilling, surface-based geophysical methods are necessary to observe fault zones and fault zone physical properties at seismogenic depths. These in situ physical properties can then be used to infer the presence and distribution of fluids along faults, although such observations are by nature indirect and become less exact with greater depth. Multiple observations of a range of such geophysical properties as compressional and shear seismic velocity (V-p and V-s), V-p/V-s ratio (related to Poisson's ratio), resistivity and attenuation in and adjacent to fault zones offer the greatest hope of making inferences of the fault zone geometry, fluids in the fault zone, and fluid reservoirs in the surrounding crust, For simple geometries, fault zone guided waves can provide information on fault zone width and velocities for faults of the order of 200 m wide. To address the question of whether a narrow fault zone can be imaged well enough at depths of seismic rupture to infer the presence of anomalously high fluid/rock ratios, we present synthetic seismic tomography and magnetotelluric examples for an ideal case of a narrow fault zone with a simple geometry, large changes in material properties, and numerous earthquakes within the fault zone. A synthetic 0.5-km wide fault zone with 20% velocity reduction is well imaged using local earthquake tomography. When sequential velocity inversions are done, the true fault width is found, even to 9 km depth, although the calculated amplitude of the velocity reduction is lower than the actual amplitude. V-p/V-s is as well determined as V-p Magnetotelluric imaging of a synthetic fault zone shows that a conductive fault zone can bk well imaged within the upper 10 km. Further, a narrow (1 km) very low resistivity (3 ohm m) fault core can be imaged within a broad (5 km) low resistivity (10 ohm m) fault zone, illustrating that regions of a fault containing large quantities of interconnected fluids within a broader, conductive fault zone should be detectable. Thus variations in fluid content and fluid pressure can be inferred from electrical and seismic methods but there will always be uncertainty in these inferences due to the trade-off with other factors, such as intrinsic variations in porosity, mineralogy, and pore geometry. The best approach is combined modeling of varied seismic and electrical data. C1 UNIV WISCONSIN, DEPT GEOL & GEOPHYS, MADISON, WI 53706 USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP INST GEOL & NUCL SCI, POB 1320, WELLINGTON, NEW ZEALAND. NR 107 TC 79 Z9 80 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12919 EP 12936 DI 10.1029/94JB03256 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200039 ER PT J AU FENOGLIO, MA JOHNSTON, MJS BYERLEE, JD AF FENOGLIO, MA JOHNSTON, MJS BYERLEE, JD TI MAGNETIC AND ELECTRIC-FIELDS ASSOCIATED WITH CHANGES IN HIGH PORE PRESSURE IN FAULT ZONES - APPLICATION TO THE LOMA-PRIETA ULF EMISSIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID FLUID-PRESSURE; EARTHQUAKE; RESISTIVITY; WATER; ANOMALIES; SYSTEMS; CALIFORNIA; VELOCITY; QUARTZ; FLOW AB We determined the electric and magnetic fields generated during failure of faults containing sealed compartments with pore pressures ranging from hydrostatic to lithostatic levels. Exhumed fault studies and strain measurement data limit the possible size of these compartments to less than 1 km in extent. Rupture of seals between compartments produces rapid pore pressure changes and fluid flow and may create fractures that propagate away from the high-pressure compartment, along the fault face. Nonuniform fluid flow results from pressure decrease in the fracture from crack-generated dilatancy, partial blockage by silica deposition, and clearing as pressure increases. A direct consequence of this unsteady fluid flow may be associated transient magnetic signals caused by electrokinetic, piezomagnetic, and magnetohydrodynamic effects. Models of these processes for fault geometries with 1-km-high pressure compartments show that electrokinetic effects are several orders of magnitude larger than the other mechanisms. The electrokinetic signals produced by this unsteady flow are comparable in magnitude and frequency to the magnetic signals observed prior to the M(L) 7.1 Loma Prieta earthquake of October 18, 1989, provided fracture lengths are less than 200 m. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP FENOGLIO, MA (reprint author), STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. NR 47 TC 109 Z9 114 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12951 EP 12958 DI 10.1029/95JB00076 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200041 ER PT J AU HILL, DP JOHNSTON, MJS LANGBEIN, JO BILHAM, R AF HILL, DP JOHNSTON, MJS LANGBEIN, JO BILHAM, R TI RESPONSE OF LONG-VALLEY CALDERA TO THE M(W)=7.3 LANDERS, CALIFORNIA, EARTHQUAKE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EASTERN CALIFORNIA; TENSILE FAULTS; HALF-SPACE; DEFORMATION; MODEL; CRYSTALLINE; PRESSURE; SYSTEMS; UNREST; STRESS AB Of the many sites in the western United States responding to the June 28, 1992, Landers earthquake (M(w) = 7.3) with remotely triggered seismicity, only Long Valley caldera is monitored by both seismic and continuous deformation networks. A transient strain pulse and surge in seismicity recorded by these networks began within tens of seconds following arrival:of the shear pulse from Landers. The cumulative strain and number of triggered earthquakes followed the same exponentially decaying growth rate (time constant 1.8 days) during the first 6 days following Landers. The strain transient, which was recorded on a borehole dilatometer at the west margin of the caldera and a long-base tiltmeter 20 km to the east, peaked on the sixth day at ;approximate to 0.25 ppm and gradually decayed over the next 15-20 days. The absence of a clear strain signal exceeding 0.4 ppm in data from the two-color geodimeter deformation lines, which span the central section of the caldera, indicates that the strain transient cannot be due solely to pressure changes in the concentrated pressure source 7 km beneath the central part of the caldera that accounts for most of the uplift of the resurgent dome since 1980. The triggered seismicity occupied the entire seismogenic volume beneath the caldera. The focal mechanisms, the frequency-magnitude distribution, and the spatial distribution of the triggered earthquakes are typical of other swarms in Long Valley caldera. The cumulative seismic moment of the triggered earthquakes through the first 2 weeks after the Landers earthquake corresponds to a single M = 3.8 earthquake, which is too small by nearly 2 orders of magnitude to account for the 0.25-ppm peak amplitude of the observed strain transients. Evidently, the strain transient represents the dominant response mode, which precludes direct triggering of local earthquakes by the large dynamic stresses from Landers as the dominant process. Conditionally viable models for the triggering process beneath the caldera include (1) the transient pressurization of magma bodies beneath the resurgent dome and Mammoth Mountain by the advective overpressure of rising bubbles, (2) a surge in fluid pressure within the seismogenic zone due to upward cascading failure of isolated compartments containing superhydrostatic pore fluids, (3) relaxation (fluidization) of a partially crystallized magma body or dike intrusion in the deep crustal roots of Long Valley magmatic system, or (4) aseismic slip on midcrustal faults. Either the deep, relaxing-magma body or lower crustal dike intrusion satisfy all the strain observations with a single deformation source. The latter model admits the possibility that large, regional earthquakes can trigger the episodic recharge of the deep roots of crustal magmatic systems. C1 UNIV COLORADO, DEPT GEOL, BOULDER, CO 80309 USA. RP HILL, DP (reprint author), US GEOL SURVEY, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 70 TC 65 Z9 68 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 12985 EP 13005 DI 10.1029/95JB00860 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200043 ER PT J AU BLANPIED, ML LOCKNER, DA BYERLEE, JD AF BLANPIED, ML LOCKNER, DA BYERLEE, JD TI FRICTIONAL SLIP OF GRANITE AT HYDROTHERMAL CONDITIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID VARIABLE NORMAL STRESS; SIMULATED FAULT GOUGE; ROCK FRICTION; CONSTITUTIVE-EQUATIONS; LABORATORY EXPERIMENTS; DEPENDENT FRICTION; WESTERLY GRANITE; HIGH-TEMPERATURE; SHEAR ZONES; STICK-SLIP AB Sliding on faults in much of the continental crust likely occurs at hydrothermal conditions, i.e., at elevated temperature and elevated pressure of aqueous pore fluids, yet there have been few relevant laboratory studies. To measure the strength, sliding behavior, and friction constitutive properties of faults at hydrothermal conditions, we slid laboratory granite faults containing a layer of granite powder (simulated gouge). Velocity stepping experiments were performed at temperatures of 23 degrees to 600 degrees C, pore fluid pressures P-H2O of 0 (''dry'') and 100 MPa (''wet''), effective normal stress of 400 MPa, and sliding velocities V of 0.01 to 1 mu m/s (0.32 to 32 m/yr). Conditions were similar to those in earlier tests on dry granite to 845 degrees C by Lockner et al. (1986). The mechanical results define two regimes. The first regime includes dry granite up to at least 845 degrees and wet granite below 250 degrees C. In this regime the coefficient of friction is high (mu = 0.7 to 0.8) and depends only modestly on temperature, slip rate, and P-H2O. The second regime includes wet granite above similar to 350 degrees C. In this regime friction decreases considerably with increasing temperature (temperature weakening) and with decreasing slip rate (velocity strengthening). These regimes correspond well to those identified in sliding tests on ultrafine quartz. We infer that one or more fluid-assisted deformation mechanisms are activated in the second, hydrothermal, regime and operate concurrently with cataclastic flow. Slip in the first (cool and/or dry) regime is characterized by pervasive shearing and particle Size reduction. Slip in the second (hot and wet) regime is localized primarily onto narrow shear bands adjacent to the gouge-rock interfaces. Weakness of these boundary shears may result either from an abundance of phyllosilicates preferentially aligned for easy dislocation glide, or from a dependence of strength on gouge particle size. Major features of the granite data set can be fit reasonably well by a rate- and temperature-dependent, three-regime friction constitutive model (Chester, this issue). We extrapolate the experimental data and model fit in order to estimate steady state shear strength versus depth along natural; slipping faults for sliding rates as low as 31 mm/yr. We do this for two end-member cases. In the first case, pore pressure is assumed hydrostatic at all depths. Shallow crustal strength in this case is similar to that calculated in previous work from room temperature friction data, while at depths below about 9-13 km (depending on slip rate), strength becomes less sensitive to depth but sensitive to slip rate. In the second case, pore pressure is assumed to be near-lithostatic at depths below similar to 5 km. Strength is low at all depths in this case (<20 MPa, in agreement with observations of ''weak'' faults such as the San Andreas). The predicted depth of transition from velocity weakening to velocity strengthening lies at about 13 km depth for a slip rate of 31 mm/yr, in rough agreement with the seismic-aseismic transition depth observed on mature continental faults. These results highlight the importance of fluid-assisted deformation processes active in faults at depth and the need for laboratory studies on the roles of additional factors such as fluid chemistry, large displacements, higher concentrations of phyllosilicates, and time-dependent fault healing. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MAIL STOP 977, MENLO PK, CA 94025 USA. NR 85 TC 248 Z9 262 U1 1 U2 31 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 13045 EP 13064 DI 10.1029/95JB00862 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200047 ER PT J AU LOCKNER, D EVANS, B AF LOCKNER, D EVANS, B TI DENSIFICATION OF QUARTZ POWDER AND REDUCTION OF CONDUCTIVITY AT 700-DEGREES-C SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID TRANSPORT-PROPERTIES; PRECIPITATION CREEP; CONTINUUM-SYSTEMS; PERMEABILITY; PRESSURE; GRANITE; POROSITY; ROCK; RESISTIVITY; TRANSITION AB We have measured axial strain, volumetric strain, and electrical conductivity during the densification at 700 degrees C of ultra-fine quartz powder (5-10 mu m diameter) saturated with distilled water. Individual experiments were run at confining pressures ranging from 200 to 370 MPa and pore pressures of 30, 100, and 200 MPa. During the experiments, which lasted from 10 hours to 8 days, the porosity decreased from an initial value of about 40% to final porosities ranging from 19% to as little as 8 +/- 1%. In all experiments, initial volumetric compaction rates were rapid (10(-5) to 10(-6) s(-1)) but decreased to between 10(-7) and 10(-8) s(-1) after approximately 1 day. Electrical conductivity also decreased monotonically from 10(-2) to 10(-4) S/m during the experiments. We present a model in which changes in conductivity are controlled by constrictions in interconnecting channels, while porosity is controlled primarily by deposition of quartz in the pores. Both experimental and model results suggest a densification process in which conductivity reduces to matrix conductivity while leaving a residual porosity of 3-5%. In the Earth, the porosity at a given instant will be the net resultant of porosity reducing processes and porosity producing processes including fracturing. The rapid loss of conductivity and, by inference, permeability suggests that in the absence of processes which increase permeability, both of these properties should have very small values in the lower crust. Furthermore, these experiments lend support to arguments that time-dependent compaction of fault gouge can play an important role in modifying fluid pressure and fault strength during the interseismic portion of the earthquake cycle for large earthquakes. C1 MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02138 USA. RP LOCKNER, D (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 45 TC 20 Z9 21 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 13081 EP 13092 DI 10.1029/94JB02818 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200049 ER PT J AU HICKMAN, SH EVANS, B AF HICKMAN, SH EVANS, B TI KINETICS OF PRESSURE SOLUTION AT HALITE-SILICA INTERFACES AND INTERGRANULAR CLAY FILMS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SURFACE FORCES; HYDRATION FORCES; PRECIPITATION CREEP; CERAMIC MATERIALS; MICA SURFACES; LIQUID-PHASE; QUARTZ SAND; WATER; FAULT; STRESS AB Pressure solution is widely regarded as a potentially important deformation mechanism along crustal faults and during diagenesis, yet the mechanisms and kinetics of this process remain highly controversial. To better understand the fundamental factors controlling the rates of pressure solution at the grain-to-grain scale, we conducted experiments in which convex halite lenses were pressed against flats of fused silica in brine. Fluid pressures were maintained at 0.1 MPa; temperatures and mean contact normal stresses ranged from 8.3 degrees to 90.2 degrees C and 0.5 to 13.5 MPa, respectively. The geometry and growth rate of the contact spot between the two lenses and the rate at which the lenses approached one another (convergence) were monitored using reflected light interferometry and transmitted light photomicrography. Convergence occurred when halite and silica lenses were pressed together in brine (halite/silica experiments). No undercutting was observed, and dry control experiments indicated negligible dislocation creep. Convergence rates in experiments at 50.2 degrees C ranged from 0.01 to 0.05 mu m/d, depending on mean normal stress and contact spot radius. The data are consistent with intergranular pressure solution (IFS) rate-limited by diffusion through an intergranular film with a very high diffusion coefficient (similar to 10(-5)-10(-7) cm(2)/s). The data further suggest that the diffusion coefficient and/or thickness of this film increases with decreasing normal stresses, at least for normal stresses less than about 4 MPa. As no island-channel boundary structures were observed, we propose that this film consists of a continuous layer of strongly adsorbed (i.e., structured) water that is maintained between the halite and silica lenses during deformation. Convergence rates in similar experiments conducted at a constant load of O.11 N but at 8.3 degrees, 50.2 degrees, and 90.2 degrees C were approximately constant at a given normal stress and contact spot size. The cause of this temperature insensitivity is unknown but might result from changes in interphase boundary structure or thickness with increasing temperature that are sufficient to offset the expected thermal activation. An experiment was also conducted in which a halite lens was pressed against a fused silica flat coated with an 0.8-mu m-thick film of Na-montmorillonite in brine. This clay film produced an approximately fivefold increase in convergence rates over those observed in a halite/silica experiment conducted without clay at the same load and temperature. The strong sensitivity of IPS rates both to contact spot radius and to the presence of second phases along grain boundaries suggests that fine-grained, clay-rich fault gouges and multiphase granular aggregates should be particularly susceptible to pressure solution creep in the middle to upper crust. C1 MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02139 USA. RP HICKMAN, SH (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 95 TC 118 Z9 118 U1 4 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUL 10 PY 1995 VL 100 IS B7 BP 13113 EP 13132 DI 10.1029/95JB00911 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH812 UT WOS:A1995RH81200051 ER PT J AU KING, CY KOIZUMI, N KITAGAWA, Y AF KING, CY KOIZUMI, N KITAGAWA, Y TI HYDROGEOCHEMICAL ANOMALIES AND THE 1995 KOBE EARTHQUAKE SO SCIENCE LA English DT Editorial Material C1 KYOTO UNIV,DISASTER PREVENT RES INST,KYOTO,JAPAN. RP KING, CY (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 5 TC 55 Z9 59 U1 0 U2 3 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 7 PY 1995 VL 269 IS 5220 BP 38 EP 39 DI 10.1126/science.269.5220.38 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RG980 UT WOS:A1995RG98000023 PM 17787700 ER PT J AU TALBOT, SS TALBOT, SL SCHOFIELD, WB AF TALBOT, SS TALBOT, SL SCHOFIELD, WB TI CONTRIBUTION TOWARD AN UNDERSTANDING OF POLYSTICHUM-ALEUTICUM C-CHR ON ADAK-ISLAND, ALASKA SO AMERICAN FERN JOURNAL LA English DT Article C1 UNIV BRITISH COLUMBIA,DEPT BOT,VANCOUVER,BC V6T 1Z4,CANADA. RP TALBOT, SS (reprint author), US FISH & WILDLIFE SERV,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. RI Talbot, Sandra/C-9433-2011 NR 13 TC 3 Z9 3 U1 1 U2 3 PU AMER FERN SOC INC PI ATLANTA PA RICHAR L HAUKE 456 MCGILL PL, ATLANTA, GA 30312-1049 SN 0002-8444 J9 AM FERN J JI Am. Fern J. PD JUL-SEP PY 1995 VL 85 IS 3 BP 83 EP 88 DI 10.2307/1547510 PG 6 WC Plant Sciences SC Plant Sciences GA TB528 UT WOS:A1995TB52800003 ER PT J AU SEILER, RL AF SEILER, RL TI VERIFICATION OF ESTIMATED GROWTH-RATES IN THE TREE FERN ALSOPHILA-SALVINII SO AMERICAN FERN JOURNAL LA English DT Note RP SEILER, RL (reprint author), US GEOL SURVEY,333 W NYE LANE,CARSON CITY,NV 89706, USA. NR 0 TC 9 Z9 11 U1 0 U2 0 PU AMER FERN SOC INC PI ATLANTA PA RICHAR L HAUKE 456 MCGILL PL, ATLANTA, GA 30312-1049 SN 0002-8444 J9 AM FERN J JI Am. Fern J. PD JUL-SEP PY 1995 VL 85 IS 3 BP 96 EP 97 DI 10.2307/1547513 PG 2 WC Plant Sciences SC Plant Sciences GA TB528 UT WOS:A1995TB52800006 ER PT J AU TAKEDA, H ROSS, M AF TAKEDA, H ROSS, M TI MICA POLYTYPISM - IDENTIFICATION AND ORIGIN SO AMERICAN MINERALOGIST LA English DT Article ID STACKING SEQUENCES; CRYSTAL-STRUCTURES; LEPIDOLITE AB Practical methods for identification of the complex mica polytypes have been developed by introducing a special function characteristic of their layer stacking sequences that is displayed in their X-ray diffraction patterns. This periodic intensity distribution (PID) function is the Fourier transform of a stacking sequence. The X-ray diffraction patterns of a polytype are expressed by the PID function modified by the Fourier transform of the unit mica layer. The PID function is used to determine the stacking sequences of several polytypes, and the mechanism by which the most frequently observed polytypes form is discussed. The axial settings of mica polytypes are defined in order to compute the PID functions in terms of the layer stacking sequences. Practical methods of obtaining observed PID functions are given together with tables of the PID functions of the three basic polytype series. The common polytypes have the basic sequences such as 1M, 3T, and 2M(1) and are modified by a stacking fault, but the subsequent sequences are so arranged that the original direction of stacking is recovered as readily as possible. C1 US GEOL SURVEY,NATL CTR 959,RESTON,VA 22092. RP TAKEDA, H (reprint author), UNIV TOKYO,FAC SCI,INST MINERAL,TOKYO 113,JAPAN. NR 38 TC 27 Z9 27 U1 1 U2 3 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL-AUG PY 1995 VL 80 IS 7-8 BP 715 EP 724 PG 10 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RN609 UT WOS:A1995RN60900008 ER PT J AU BOHLEN, SR ECKERT, JO HANKINS, WB AF BOHLEN, SR ECKERT, JO HANKINS, WB TI EXPERIMENTALLY DETERMINED SOLIDI IN THE CA-BEARING GRANITE SYSTEM NAALSI3O8-CAAL2SI2O8-KALSI3O8-SIO2-H2O-CO2 SO AMERICAN MINERALOGIST LA English DT Article ID MODEL; WATER AB We have determined the phase relationships of melting of synthetic granite (two ternary feldspars + quartz) in the presence of an H2O-CO2 fluid. Synthesis and reversed experiments were conducted in a piston-cylinder apparatus over the range 650-900 degrees C and 6-15 kbar. At X(H2O) = 0.75, melting occurred between 670 and 680 degrees C (15 kbar), 700 and 710 degrees C (10 kbar), and 710 and 720 degrees C (7.4 kbar). At X(H2O) = 0.5, melting occurred between 760 and 770 degrees C (15 kbar), 780 and 790 degrees C (10 kbar), and 800 and 820 degrees C (6-7.4 kbar). At X(H2O) = 0.25, melting occurred between 830 and 840 degrees C (15 kbar), 830 and 840 degrees C (10 kbar), and 860 and 870 degrees C (6-7.4 kbar). These results provide important constraints on the maximum temperatures of regional metamorphism attainable in vapor-saturated metapelitic and quartzofeldspathic rocks that escaped widespread melting. At pressures below 10 kbar, a fluid phase of X(H2O) = 0.75, 0.5, and 0.25 limits temperatures to below similar to 700-725, similar to 800-825, and similar to 850-875 degrees C, respectively. As a consequence, the formation of granulite does not require CO2 concentrations in a coexisting fluid to exceed an X(co2) of 0.25-0.5, a range that may include dilution of the H2O component of the fluid through internal buffering by devolatilization reactions. Therefore, the formation of granulites by the influx of CO2 may be a less common phenomenon than previously thought. RP BOHLEN, SR (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 910,MENLO PK,CA 94025, USA. NR 18 TC 7 Z9 8 U1 1 U2 2 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL-AUG PY 1995 VL 80 IS 7-8 BP 752 EP 756 PG 5 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RN609 UT WOS:A1995RN60900012 ER PT J AU CHOU, IM BASSETT, WA BAI, TB AF CHOU, IM BASSETT, WA BAI, TB TI HYDROTHERMAL DIAMOND-ANVIL CELL STUDY OF MELTS - EUTECTIC MELTING OF THE ASSEMBLAGE CA(OH)(2)+CACO3 WITH EXCESS H2O AND LACK OF EVIDENCE FOR PORTLANDITE-II PHASE SO AMERICAN MINERALOGIST LA English DT Letter ID PRESSURES AB Eutectic melting temperatures for the assemblage Ca(OH)(2) + CaCO3 in the presence of excess H2O were determined along six isochores of H2O in a hydrothermal diamond-anvil cell. These temperatures range from 610 degrees C at 1204 bar to 583 degrees C at 7203 bar; they agree very well (within 3 degrees C) with data obtained from high-pressure differential thermal analysis (HP-DTA) and are about 20 degrees C lower than those obtained from quench experiments. The additional DTA peaks near 630 degrees C for the melting experiments of pure portlandite reported by Harker (1964) and Bai et al. (1994) may be the result of a small amount of melting, caused by CaCO3 contamination, and not the result of a solid phase transition between portlandite and ''portlandite II.'' C1 CORNELL UNIV,DEPT GEOL SCI,ITHACA,NY 14853. UNIV ILLINOIS,DEPT GEOL SCI,CHICAGO,IL 60607. RP CHOU, IM (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 13 TC 3 Z9 3 U1 0 U2 1 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL-AUG PY 1995 VL 80 IS 7-8 BP 865 EP 868 PG 4 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RN609 UT WOS:A1995RN60900029 ER PT J AU OREMLAND, RS MILLER, LG DOWDLE, P CONNELL, T BARKAY, T AF OREMLAND, RS MILLER, LG DOWDLE, P CONNELL, T BARKAY, T TI METHYLMERCURY OXIDATIVE-DEGRADATION POTENTIALS IN CONTAMINATED AND PRISTINE SEDIMENTS OF THE CARSON RIVER, NEVADA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MERCURY METHYLATION; INTERTIDAL SEDIMENTS; WATER; DEMETHYLATION; SULFATE; REDUCTION; RESISTANCE; METHANE; LAKE; VOLATILIZATION AB Sediments from mercury-contaminated and uncontaminated reaches of the Carson River, Nevada, were assayed for sulfate reduction, methanogenesis, denitrification, and monomethylmercury (MeHg) degradation. Demethylation of [C-14]MeHg was detected at all sites as indicated by the formation of (CO2)-C-14 and (CH4)-C-14. Oxidative demethylation was indicated by the formation of (CO2)-C-14 and was present at significant levels in all samples. Oxidized/reduced demethylation product ratios (i.e., (CO2)-C-14/(CH4)-C-14 ratios) generally ranged from 4.0 in surface layers to as low as 0.5 at depth. Production of (CO2)-C-14 was most pronounced at sediment surfaces which were zones of active denitrification and sulfate reduction but was also significant within zones of methanogenesis. In a core taken from an uncontaminated site having a high proportion of oxidized, coarse-grain sediments, sulfate reduction and methanogenic activity levels were very low and (CO2)-C-14 accounted for 98% of the product formed from [C-14]MeHg. There was no apparent relationship between the degree of mercury contamination of the sediments and the occurrence of oxidative demethylation. However, sediments from Fort Churchill, the most contaminated site, were most active in terms of demethylation potentials. Inhibition of sulfate reduction with molybdate resulted in significantly depressed oxidized/reduced demethylation product ratios, but overall demethylation rates of inhibited and uninhibited samples were comparable. Addition of sulfate to sediment slurries stimulated production of (CO2)-C-14 from [C-14]MeHg, while 2-bromoethanesulfonic acid blocked production of (CH4)-C-14. These results reveal the importance of sulfate-reducing and methanogenic bacteria in oxidative demethylation of MeHg in anoxic environments. C1 US EPA,ENVIRONM RES LAB,GULF BREEZE,FL 32561. RP OREMLAND, RS (reprint author), US GEOL SURVEY,MS 465,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 57 TC 57 Z9 60 U1 0 U2 6 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUL PY 1995 VL 61 IS 7 BP 2745 EP 2753 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA RG334 UT WOS:A1995RG33400048 PM 16535081 ER PT J AU WILLIAMS, LL GIESY, JP VERBRUGGE, DA JURZYSTA, S HEINZ, G STROMBORG, K AF WILLIAMS, LL GIESY, JP VERBRUGGE, DA JURZYSTA, S HEINZ, G STROMBORG, K TI POLYCHLORINATED-BIPHENYLS AND 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN EQUIVALENTS IN EGGS OF RED-BREASTED MERGANSERS NEAR GREEN-BAY, WISCONSIN, USA, IN 1977-78 AND 1990 SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DOUBLE-CRESTED CORMORANTS; FISH-EATING BIRDS; DIBENZO-PARA-DIOXINS; LAKES FOOD-CHAINS; GREAT-LAKES; DEVELOPMENTAL TOXICANTS; REPRODUCTIVE OUTCOMES; PCB CONGENERS; RESIDUES; HYDROCARBONS AB The hypothesis that the concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEqs) contributed by non-ortho- and mono-ortho-substituted (coplanar) PCB congeners have changed relative to total concentrations of PCBs over time was tested by analyzing eggs of red-breasted mergansers collected from the same locality in 1977-78 and in 1990. Twelve eggs from each time period were analyzed for coplanar PCBs, using a porous graphitic carbon HPLC column and GC-ECD. TEqs were calculated from coplanar PCB concentrations and bioassay-derived toxic equivalency factors. Median total PCB concentrations decreased from 25 to 13 mu g/g, fresh weight (fw), and TEqs decreased from 320 pg/g to 160 pg/g, fw. The relative potency of the PCB mixtures, expressed as the ratio of TEqs contributed by the coplanar PCB congeners to total PCBs, did not change, nor did the ratio of concentrations of coplanar congeners to total PCBs. Thus, the relative potency of the mixture of PCBs in the eggs has not changed even as the concentrations declined significantly. The greater relative potency of TEqs relative to that which would be expected from the Aroclor(R) mixtures released into the environment is due to selective bioaccumulation, biomagnification, and metabolism, rather than as a result of differential weathering as a function of time. C1 MICHIGAN STATE UNIV,DEPT FISHERIES & WILDLIFE,PESTICIDE RES CTR,E LANSING,MI 48824. MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,E LANSING,MI 48824. PATUXENT ENVIRONM SCI CTR,LAUREL,MD 20708. US FISH & WILDLIFE SERV,GREEN BAY FIELD OFF,GREEN BAY,WI 54311. NR 37 TC 8 Z9 8 U1 1 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD JUL PY 1995 VL 29 IS 1 BP 52 EP 60 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RA088 UT WOS:A1995RA08800010 ER PT J AU Stewart, DB Unger, JD Hutchinson, DR AF Stewart, DB Unger, JD Hutchinson, DR TI Silurian tectonic history of Penobscot Bay region, Maine SO ATLANTIC GEOLOGY LA English DT Article ID SEISMIC-REFLECTION PROFILES; SOUTHWESTERN NEW-BRUNSWICK; AVALON COMPOSITE TERRANE; NORTHERN APPALACHIANS; NEWFOUNDLAND APPALACHIANS; REVISED STRATIGRAPHY; THERMAL HISTORIES; KINGSTON COMPLEX; COASTAL MAINE; COOKSON-GROUP AB Early Paleozoic amalgamation of composite terranes was contemporaneous at widely separated regions that were later accreted to either ancestral North America or to Gondwana as those two continents approached each other. Terranes closer to Laurentia amalgamated in the Late Cambrian to Middle Ordovician Penobscottian orogeny and were accreted to ancestral North America in the Middle and to Late Orodovician Taconic orogeny. PeriGondwanan terranes formed from Late Cambrian and Early Ordovician rocks were amalgamated in the Late Ordovician and Early Silurian to form the Salinic orogenic belt, now exposed from western Europe to southern New England. Salinic orogenic activity involved extensive thrust faulting and metamorphism, large strike-slip faults, and plutonism, all of which are represented in coastal Maine. In the Penobscot Bay region, Maine, the periGondwanan St. Croix terrane was thrust northwest in the Silurian(?) upon middle amphibolite facies Ordovician and Early Silurian rocks of the Fredericton trough. Seismic reflection profiles show that the thrust fault dips southeasterly at similar to 30 degrees and becomes listric at about 13 +/- 2 km. The thrust sheet was broken initially by the Late Silurian Penobscot Bay-Smith Cove-North Blue Hill dextral strike-slip fault which juxtaposed the peri-Gondwanan Ellsworth terrane, followed by emplacement of the South Penobscot Intrusive Suite and by a sequence of strike-slip fault zones each with up to 20 km of dextral Silurian and Early Devonian(?) movement. The strike-slip faults are interpreted to either remain steep until they reach the sole of the thrust sheet or to become listric within the thrust sheet. In the Devonian Acadian orogeny, more outboard terranes with Gondwanan affinities, like the Avalonian terranes in southern New Brunswick and in eastern Massachusetts, were amalgamated with the Silurian orogenic belt, and the resulting composite terrane was accreted to ancestral North America. Acadian deformation, metamorphism, and plutonism are superimposed on the Silurian orogen, blurring or obliterating the evidence of Silurian orogeny. RP Stewart, DB (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 75 TC 16 Z9 16 U1 0 U2 3 PU ATLANTIC GEOLOGY PI WOLFVILLE PA BOX 115, ACADIA UNIV, WOLFVILLE NS B0P 1X0, CANADA SN 0843-5561 J9 ATLANTIC GEOL JI Atl. Geol. PD JUL PY 1995 VL 31 IS 2 BP 67 EP 79 PG 13 WC Geology SC Geology GA TP287 UT WOS:A1995TP28700001 ER PT J AU HICKSON, CJ MOORE, JG CALK, L METCALFE, P AF HICKSON, CJ MOORE, JG CALK, L METCALFE, P TI INTRAGLACIAL VOLCANISM IN THE WELLS-GRAY CLEARWATER VOLCANIC FIELD, EAST-CENTRAL BRITISH-COLUMBIA, CANADA SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article ID SUBMARINE LAVAS; ICELAND; ROCKS; PERALKALINE; HAWAII; SULFUR AB Small-volume, subaerial, subaqueous and subglacial basaltic eruptions occurred in the Wells Gray - Clearwater area during Quaternary time. Part of this time, significant thicknesses of glacial ice were present. Dating of intraglacial volcanic features corroborates other evidence of an Early Pleistocene, Cordilleran-wide ice sheet. Of the intraglacial volcanoes investigated, three were studied in detail and of these, two probably erupted during the Fraser glaciation (11-20 ka), when maximum ice level exceeded 2100 m elevation. Major-element and sulphur concentrations were measured in glass from the volcanoes to provide insight into vent conditions at the time of eruption. Hyalo Ridge (2102 m elevation, whole-rock K-Ar age of 0.02 +/- 0.01 Ma) is a small volcanic edifice capped by lava flows with coherent pillowed lavas and interbedded hyaloclastite exposed over nearly 400 m altitude on its east flank. Low sulphur content (<0.03 wt.%) in pillow rim glasses indicates that the lavas are degassed. It is interpreted that the vent built above the water (or ice) surface then fed lava flows that crossed a shoreline and produced pillowed flows. Pyramid Mountain is a volcanic cone 240 m high, comprised of glassy, vesicular, lapilli-tuff breccia. The highly alkalic glass contains 0.1 wt.% S (considered high), and indicates a high original volatile content and drastic quenching, probably during phreatomagmatic eruption from a meltwater-flooded vent. East of the Clearwater River a sequence of massive pillowed flows and pillow joint-block breccias is exposed from 880 to 1320 m elevation (0.27 +/- 0.05 Ma). The vent location is unknown. Moderate S content (0.040-0.055 wt.%) indicates that the lavas were erupted in shallow water and are largely degassed. The S content of glass in dykes cutting the pillow breccias is low. The dykes are interpreted as lava that has flowed laterally or down into cracks. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP HICKSON, CJ (reprint author), GEOL SURVEY CANADA, 100 W PENDER ST, VANCOUVER, BC V6B 1R8, CANADA. NR 33 TC 19 Z9 19 U1 1 U2 3 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD JUL PY 1995 VL 32 IS 7 BP 838 EP 851 DI 10.1139/e95-070 PG 14 WC Geosciences, Multidisciplinary SC Geology GA RZ634 UT WOS:A1995RZ63400002 ER PT J AU EDMONDS, RL THOMAS, TB AF EDMONDS, RL THOMAS, TB TI DECOMPOSITION AND NUTRIENT RELEASE FROM GREEN NEEDLES OF WESTERN HEMLOCK AND PACIFIC SILVER FIR IN AN OLD-GROWTH TEMPERATE RAIN-FOREST, OLYMPIC NATIONAL-PARK, WASHINGTON SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Article ID LEAF-LITTER DECOMPOSITION; LONG-TERM DECOMPOSITION; SOIL ORGANIC-MATTER; NITROGEN IMMOBILIZATION; LIGNIN CONTENT; MASS-LOSS; DYNAMICS; RATES; ECOSYSTEMS; CHEMISTRY AB Decomposition rates and nutrient dynamics (for N, P, K, Ca, Mg, Mn, and Na) were determined for green needles of western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Pacific silver fir (Abies amabilis (Dougl.) Forb.) in an old-growth forested watershed (58 ha West Twin Creek) in the Hoh River valley, Olympic National Park, Washington. The influence of temperature and substrate chemistry on decomposition was determined. Temperature was the dominant factor controlling decomposition rates in the first year in this watershed, with the fastest decomposition at an elevation of 275 m (lower watershed) and the slowest decomposition at 725 m (upper watershed). After 12 months mass loss averaged 36% in the lower watershed and 28% in the upper watershed. There was no significant difference in decomposition rates between species. Substrate chemistry, i.e., the lignin/N ratio, became a more important factor than temperature as decomposition proceeded. After 37 months mass loss for needles averaged 61% for western hemlock and 50% for Pacific silver fir, with no difference by watershed location. After 61 months both types of substrates appeared to be approaching similar substrate chemistry and similar decomposition rates and there were no significant differences by species or watershed location. Decomposition constants (k values) after 61 months were 0.26 and 0.20 year(-1) for western hemlock needles in the lower and upper watershed, respectively, and 0.22 and 0.19 year(-1) for Pacific silver fir needles in the lower and upper watershed, respectively. Nitrogen was immobilized during the first 12 months of decomposition in needles of both species and then released. No other elements were immobilized during the initial (0- to 12-month) decomposition period, except for Ca in Pacific silver fir needles. However, in the 37- to 61-month period there was a considerable immobilization of Mg and Na in both species in the upper and lower watershed and K and Mn in both species in the upper watershed. C1 US FISH & WILDLIFE SERV,ECOL SERV,OLYMPIA,WA 98501. RP EDMONDS, RL (reprint author), UNIV WASHINGTON,COLL FOREST RESOURCES,SEATTLE,WA 98195, USA. NR 28 TC 16 Z9 27 U1 2 U2 18 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0045-5067 J9 CAN J FOREST RES JI Can. J. For. Res.-Rev. Can. Rech. For. PD JUL PY 1995 VL 25 IS 7 BP 1049 EP 1057 PG 9 WC Forestry SC Forestry GA RT505 UT WOS:A1995RT50500001 ER PT J AU ZARTMAN, RE CUNNINGHAM, CG AF ZARTMAN, RE CUNNINGHAM, CG TI U-TH-PB ZIRCON DATING OF THE 13.8-MA DACITE VOLCANIC DOME AT CERRO-RICO-DE-POTOSI, BOLIVIA SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID ROCKS; AGES; MINERALIZATION; ISOTOPE; BELT AB The temporal relationship between the extrusion of the Miocene dacite volcanic dome at Cerro Rico de Potosi, Bolivia, and the associated Ag-Sn mineralization has an important bearing on the heat and metal sources for this world class mineral deposit. The highly altered nature of the volcanic rock, however, has prevented previous efforts from definitively determining the emplacement age of the dome rather than subsequent episodes of alteration. The present study uses U-Th-Pb dating of sparse zircon contained in the dacite to demonstrate that, at most, only several hundred thousand years separate dome emplacement from main stage mineralization. The dacite contains a morphologically heterogeneous population of zircon with considerable variation in size, shape and color. Preliminary analyses revealed the presence of a significant component of inherited zircon, most likely as older cores that were overgrown by rims during the crystallization of the dacite magma. Morphological distinctions (shape, size, color) within the zircon population provided the basis for separating the zircon into fractions that reduced or enhanced the inherited component in composite grains. By analyzing the tips of zircon with very large length-to-width ratios, it was possible to constrain the crystallization age of the dacite to 13.8 +/- 0.2 Ma. The dispersion of data on a concordia diagram indicates at least two ages of inherited zircon, one Mesozoic associated with yellow grains, and another Proterozoic associated with colorless grains. Such xenocrystic components have useful petrogenetic implications for the source and travel path of the magma. C1 US GEOL SURVEY,RESTON,VA 22092. RP ZARTMAN, RE (reprint author), US GEOL SURVEY,BOX 25046,MAIL STOP 963,DENVER,CO 80225, USA. NR 16 TC 14 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUL PY 1995 VL 133 IS 3-4 BP 227 EP 237 DI 10.1016/0012-821X(95)00093-R PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RP780 UT WOS:A1995RP78000001 ER PT J AU LANDA, ER GRAY, JR AF LANDA, ER GRAY, JR TI US GEOLOGICAL SURVEY-RESEARCH ON THE ENVIRONMENTAL FATE OF URANIUM MINING AND MILLING WASTES SO ENVIRONMENTAL GEOLOGY LA English DT Article DE URANIUM MINING; MILLING WASTES; RADIONUCLIDES ID EMANATION COEFFICIENTS; TAILINGS; RA-226; DISSOLUTION; CONTAMINATION; REDUCTION; ALKALINE; RADIUM AB Studies by the US Geological Survey (USGS) of uranium mill tailings (UMT) have focused on characterizing the forms in which radionuclides are retained and identifying factors influencing the release of radionuclides to air and water. Selective extraction studies and studies of radionuclide sorption by and leaching from components of UMT showed alkaline earth sulfate and hydrous ferric oxides to be important hosts of radium-226 (Ra-226) in UMT. Extrapolating from studies of barite dissolution in anerobic lake sediments, the leaching of Ra-226 from UMT by sulfate-reducing bacteria was investigated; a marked increase in Ra-226 release to aqueous solution as compared to sterile controls was demonstrated. A similar action of iron(III)-reducing bacteria was later shown. Ion exchangers such as clay minerals can also promote the dissolution of host-phase minerals and thereby influence the fate of radionuclides such as Ra-226. Radon release studies examined particle size and ore composition as variables. Aggregation of UMT particles was shown to mask the higher emanating fraction of finer particles. Studies of various ores and ore components showed that UMT cannot be assumed to have the same radon-release characteristics as their precursor ores, nor can Ra-226 retained by various substrates be assumed to emanate the same fraction of radon. Over the last decade, USGS research directed at offsite mobility of radionuclides from uranium mining and milling processes has focused on six areas: the Midnite Mine in Washington; Ralston Creek and Reservoir, Colorado; sites near Canon City, Colorado; the Monument Valley District of Arizona and Utah; the Cameron District of Arizona; and the Puerco River basin of Arizona and New Mexico. RP LANDA, ER (reprint author), US GEOL SURVEY,430 NATL CTR,RESTON,VA 22092, USA. NR 48 TC 40 Z9 40 U1 4 U2 27 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD JUL PY 1995 VL 26 IS 1 BP 19 EP 31 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA RJ260 UT WOS:A1995RJ26000002 ER PT J AU KUIVILA, KM FOE, CG AF KUIVILA, KM FOE, CG TI CONCENTRATIONS, TRANSPORT AND BIOLOGICAL EFFECTS OF DORMANT SPRAY PESTICIDES IN THE SAN-FRANCISCO ESTUARY, CALIFORNIA SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE PESTICIDES; SAN FRANCISCO ESTUARY; TOXICITY; DIAZINON; METHIDATHION AB The transport and biological effects of dormant spray pesticides were examined in the San Francisco Estuary, California, by measuring dissolved-pesticide concentrations and estimating toxicity using bioassays at a series of sites in January and February 1993. Distinct pulses of pesticides, including diazinon, methidathion, and chlorpyrifos, were detected in the San Joaquin River in January and February and in the Sacramento River in February following rainfall. The higher pesticide loads in the Sacramento River compared with those in the San Joaquin River can be attributed to the greater amount of rainfall in the Sacramento Valley. The use patterns and water solubility of the pesticides can account for the observed temporal and spatial distributions in the two rivers. The pesticide pulses detected at Sacramento were followed through the northern embayment of San Francisco Estuary. In contrast, the pesticide distribution in the Sacramento-San Joaquin Delta changed from distinct pulses to steady increases in concentration over time. Seven-day bioassays indicated that Sacramento River water at Rio Vista was acutely toxic to Ceriodaphnia dubia (water flea) for 3 consecutive d and San Joaquin River water at Vernalis for 12 consecutive d. These water samples all had the highest diazinon concentrations. Examination of 96-h LC50 values (lethal concentration that kills 50% of test organisms in 96 H) indicates that measured diazinon concentrations could account for most but not ah the observed toxicity. Other pesticides present could contribute to the toxicity. C1 CALIF REG WATER QUAL CONTROL BOARD,SACRAMENTO,CA 95827. RP KUIVILA, KM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,ROOM W-2233,2800 COTTAGE WAY,SACRAMENTO,CA 95825, USA. NR 27 TC 108 Z9 108 U1 2 U2 20 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUL PY 1995 VL 14 IS 7 BP 1141 EP 1150 DI 10.1897/1552-8618(1995)14[1141:CTABEO]2.0.CO;2 PG 10 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA RE415 UT WOS:A1995RE41500004 ER PT J AU CAFFREY, JM MILLER, LG AF CAFFREY, JM MILLER, LG TI A COMPARISON OF 2 NITRIFICATION INHIBITORS USED TO MEASURE NITRIFICATION RATES IN ESTUARINE SEDIMENTS SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE NITRIFICATION; SEDIMENT; INHIBITOR; ESTUARY ID NITROUS-OXIDE; NITRIFYING BACTERIA; MARINE-SEDIMENTS; METHYL-FLUORIDE; DIMETHYL ETHER; NORTH-SEA; DENITRIFICATION; OXIDATION; AMMONIUM; COASTAL AB Nitrification rates were measured using intact sediment cores from South San Francisco Bay and two different nitrification inhibitors: acetylene and methyl fluoride. Sediment oxygen consumption and ammonium and nitrate fluxes were also measured in these cores. Four experiments were conducted in the spring, and one in the fall of 1993. There was no significant difference in nitrification rates measured using the two inhibitors, which suggests that methyl fluoride can be used as an effective inhibitor of nitrification. Nitrification was positively correlated with sediment oxygen consumption and numbers of macrofauna. This suggests that bioturbation by macrofauna is an important control of nitrification rates. Irrigation by the tube-dwelling polychaete, Asychis elongata, which dominates the benthic biomass at this location, appears particularly important. Ammonium fluxes out of the sediment were greatest about one week after the spring bloom, while nitrification peaked about one month later. RP CAFFREY, JM (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 496,MENLO PK,CA 94025, USA. NR 36 TC 22 Z9 24 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD JUL PY 1995 VL 17 IS 3 BP 213 EP 219 DI 10.1111/j.1574-6941.1995.tb00145.x PG 7 WC Microbiology SC Microbiology GA RQ457 UT WOS:A1995RQ45700008 ER PT J AU DEVIVO, B TOROK, K AYUSO, RA LIMA, A LIRER, L AF DEVIVO, B TOROK, K AYUSO, RA LIMA, A LIRER, L TI FLUID INCLUSION EVIDENCE FOR MAGMATIC SILICATE/SALINE/CO2 IMMISCIBILITY AND GEOCHEMISTRY OF ALKALINE XENOLITHS FROM VENTOTENE ISLAND, ITALY SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ROMAN REGION; MELT; MANTLE; EVOLUTION; NODULES; LAVAS; ROCKS; KBAR; CO2; SR AB Fluid and melt inclusions and geochemical features of alkali syenite, mafic, and ultramafic cumulate xenoliths in the last ignimbritic event (volcanism up to 300 ky.b.P.) at the island of Ventotene in the Pontine archipelago (Gaeta Gulf) were investigated to establish the genesis and evolution of the fluids trapped in the inclusions. Ranges in lead isotopic compositions of the xenoliths as a group are narrow: Pb-206/Pb-204:18.778-18.864; (207)pb/(204)pb:15.641-15.701; (208)pb/(204)pb:38.858-39.090; the values overlap among the groups, implying that the xenoliths are closely related. The xenoliths straddle the best-fit line describing the regional NW-SE variation of values for uranogenic Pb in volcanic rocks from the Roman alkaline province. The similarity between the xenoliths and volcanic rocks permits the interpretation that the xenoliths are representative of the source region of the volcanic rocks, residues after partial melting of the source region or fractional crystallization of the volcanic rocks, or even that the xenoliths represent assimilants obtained during the evolution of the magmas that produced the volcanic rocks. Xenoliths belonging to the ultramafic-mafic cumulate group contain only silicate melt inclusions +/- vapor bubble +/- droplets of an opaque phase and rarely some CO2 trapped in silicate melt inclusions. Xenoliths in the alkali syenite group have three types of fluid inclusions: (1) single phase vapor and silicate melt inclusions; (2) two-phase silicate melt + salt, silicate melt + CO2 (V), aqueous (L + V), and silicate melt + vapor inclusions, and (3) three-phase and multiphase inclusions: CO2 (L) + CO2 (V) + H2O; silicate melt + saline melt + H2O +/- birefringent or opaque trapped minerals; H2O + salt + silicate glass +/- birefringent trapped minerals. During heating experiments, melting of salt occurs at temperatures from 565 to 815 degrees C, depending on the water content of the inclusions. Homogenization of the vapor bubble occurs from 850-1160 degrees C, and complete melting of the silicate glass at about 950 degrees C. The highly variable proportions of the individual phases in the silicate melt + salt + H2O inclusions and the coexistence of silicate melt + CO2 inclusions indicates immiscibility during the crystallization of the magma. Primary and secondary CO2 inclusions in the alkali syenite suite indicate lower densities (from 0.10 to 0.22 g/cm(3)) than those resulting from primary CO2 inclusions in the gabbroic suite (from 0.34 to 0.42 g/cm(3)). The P-T trajectory of the probable fluid evolution path shows that the crystallization of gabbro occurred between similar to 1 and 1.4 kbars, whereas alkali syenite crystallized between similar to 200 and 400 bars. The secondary H2O inclusions in alkali syenite were trapped in the later stages of the hydrothermal process and at much lower temperatures (130-290 degrees C), but at pressures relatively close to those of alkali syenite crystallization. The almost isobaric conditions during the final stage of the fluid evolution path are explained by the very shallow emplacement of the alkali syenite intrusive body. C1 EOTVOS LORAND UNIV, DEPT PETROG & GEOCHEM, H-1088 BUDAPEST, HUNGARY. US GEOL SURVEY, RESTON, VA 22092 USA. RP DIPARTIMENTO GEOFIS & VULCANOL, VIA MEZZOCANNONE 8, I-80134 NAPLES, ITALY. NR 48 TC 36 Z9 36 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUL PY 1995 VL 59 IS 14 BP 2941 EP 2953 DI 10.1016/0016-7037(95)00186-7 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RL888 UT WOS:A1995RL88800005 ER PT J AU TENBRINK, US SCHNEIDER, C AF TENBRINK, US SCHNEIDER, C TI GLACIAL MORPHOLOGY AND DEPOSITIONAL SEQUENCES OF THE ANTARCTIC CONTINENTAL-SHELF SO GEOLOGY LA English DT Article ID ICE-SHEET AB We propose a simple model for the unusual depositional sequences and morphology of the Antarctic continental shelf. Our model considers the regional stratal geometry and the reversed morphology of the Antarctic continental shelf to be principally the results of time-integrated effects of glacial erosion and sedimentation related to the location of the ice grounding line. The model offers several guidelines for stratigraphic interpretation of the Antarctic shelf and a Northern Hemisphere shelf, both of which were subject to many glacial advances and retreats. RP TENBRINK, US (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. RI ten Brink, Uri/A-1258-2008 OI ten Brink, Uri/0000-0001-6858-3001 NR 17 TC 10 Z9 10 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 1995 VL 23 IS 7 BP 580 EP 584 DI 10.1130/0091-7613(1995)023<0580:GMADSO>2.3.CO;2 PG 5 WC Geology SC Geology GA RG180 UT WOS:A1995RG18000001 ER PT J AU ROWAN, EL GOLDHABER, MB AF ROWAN, EL GOLDHABER, MB TI DURATION OF MINERALIZATION AND FLUID-FLOW HISTORY OF THE UPPER MISSISSIPPI VALLEY ZINC-LEAD DISTRICT SO GEOLOGY LA English DT Article ID NORTH-AMERICA; GROUNDWATER; SPHALERITE; WISCONSIN; DEPOSITS; GENESIS AB Studies of fluid inclusions in sphalerite and biomarkers from the Upper Mississippi Valley zinc district show homogenization temperatures to be primarily between 90 and 150 degrees C, yet show relatively low levels of thermal maturity. We use numerical calculations to simulate fluid and heat flow through fracture-controlled ore zones and heat transfer to the adjacent rocks. Combining a best-fit path through fluid-inclusion data with measured thermal alteration of biomarkers, we calculated the time interval during which mineralizing fluids circulated through the Upper Mississippi Valley district to be on the order of 200 ka. Cambrian and Ordovician aquifers underlying the district, principally the St. Peter add Mt. Simon Sandstones, were the source of the mineralizing fluid. The duration of mineralization thus reflects the fluid-flow history of these regional aquifers. C1 US GEOL SURVEY,DENVER,CO 80225. RP ROWAN, EL (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 24 TC 24 Z9 25 U1 0 U2 4 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 1995 VL 23 IS 7 BP 609 EP 612 DI 10.1130/0091-7613(1995)023<0609:DOMAFF>2.3.CO;2 PG 4 WC Geology SC Geology GA RG180 UT WOS:A1995RG18000008 ER PT J AU PAGE, RA PLAFKER, G PULPAN, H AF PAGE, RA PLAFKER, G PULPAN, H TI BLOCK ROTATION IN EAST-CENTRAL ALASKA - A FRAMEWORK FOR EVALUATING EARTHQUAKE POTENTIAL SO GEOLOGY LA English DT Article ID COPPER RIVER BASIN; CHUGACH MOUNTAINS; CRUSTAL TRANSECT; SOUTHERN ALASKA; FAULT SYSTEM; CALIFORNIA; TERRANES; RANGE AB Geologic and seismic data reveal a set of parallel, active, strike-slip faults in east-central Alaska between the Denali and Tintina fault systems. The faults strike northeast to north-northeast, at a high angle to the bounding dextral fault systems, and exhibit sinistral slip. We hypothesize that this set of faults divides the crust into long blocks that are rotating clockwise in response to northerly compression resulting from Pacific-North American plate convergence. We suggest that these faults have produced most of the large historical earthquakes in east-central Alaska between the Alaska Range and the Yukon River. C1 UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775. RP PAGE, RA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 25 TC 32 Z9 33 U1 0 U2 2 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 1995 VL 23 IS 7 BP 629 EP 632 DI 10.1130/0091-7613(1995)023<0629:BRIECA>2.3.CO;2 PG 4 WC Geology SC Geology GA RG180 UT WOS:A1995RG18000013 ER PT J AU FOOSE, MP MCLELLAND, JM AF FOOSE, MP MCLELLAND, JM TI PROTEROZOIC LOW-TI IRON-OXIDE DEPOSITS IN NEW-YORK AND NEW-JERSEY - RELATION TO FE-OXIDE (CU-U-AU-RARE EARTH ELEMENT) DEPOSITS AND TECTONIC IMPLICATIONS SO GEOLOGY LA English DT Article ID ADIRONDACK MOUNTAINS; EVOLUTION; METAMORPHISM; TEMPERATURE; PRESSURE; ORIGIN; MTS AB Low-Ti iron-oxide deposits in exposed Grenville-age racks of New York and New Jersey belong to a distinct class of iron-oxide (Cu-U-Au-rare earth element [REE]) deposits that includes similar iron deposits in southeastern Missouri and the Kiruna district of Sweden, the giant Olympic Dam U-Cu-Au-Ag deposit (Australia), and the Bayan Obo REE-Nb deposit (China). Most of the New York-New Jersey deposits exhibit features consistent with a hydrothermal origin and define a regionally significant metallogenic event that provides important clues to the evolution of this part of the Grenville orogen. In the Adirondacks, the tectonic setting of these deposits is consistent with postorogenic uplift and extensive crustal melting at 1070-1050 Ma that was accompanied by late tectonic to posttectonic deposition of iron. C1 COLGATE UNIV,DEPT GEOL,HAMILTON,NY 13347. RP FOOSE, MP (reprint author), US GEOL SURVEY,MAIL STOP 954,RESTON,VA 22092, USA. NR 32 TC 40 Z9 40 U1 1 U2 6 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 1995 VL 23 IS 7 BP 665 EP 668 DI 10.1130/0091-7613(1995)023<0665:PLTIOD>2.3.CO;2 PG 4 WC Geology SC Geology GA RG180 UT WOS:A1995RG18000022 ER PT J AU KENNETT, BLN ENGDAHL, ER BULAND, R AF KENNETT, BLN ENGDAHL, ER BULAND, R TI CONSTRAINTS ON SEISMIC VELOCITIES IN THE EARTH FROM TRAVEL-TIMES SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE CORE PHASES; P WAVES; S WAVES; SEISMIC VELOCITIES; TRAVEL-TIMES ID INNER CORE; TIMES; MODEL AB New empirical traveltime curves for the major seismic phases have been derived from the catalogues of the International Seismological Centre by relocating events by using P readings, depth phases and the iasp91 traveltimes, and then re-associating phase picks, A smoothed set of traveltime tables is extracted by a robust procedure which gives estimates of the variance of the traveltimes for each phase branch. This set of smoothed empirical times is then used to construct a range of radial velocity profiles, which are assessed against a number of different measures of the level of fit between the empirical times and the predictions of the models. These measures are constructed from weighted sums of L(2) misfits for individual phases. The weights are chosen to provide a measure of the probable reliability of the picks for the different phases. A preferred model, ak135, is proposed which gives a significantly better fit to a broad range of phases than is provided by the iasp91 and sp6 models. The differences in velocity between ak135 and these models are generally quite small except at the boundary of the inner core, where reduced velocity gradients are needed to achieve satisfactory performance for PKP differential time data. The potential resolution of velocity structure has been assessed with the aid of a non-linear search procedure in which 5000 models have been generated in bounds about ak135, Misfit calculations are performed for each of the phases in the empirical traveltime sets, and the models are then sorted using different overall measures of misfit. The best 100 models for each criterion are displayed in a model density plot which indicates the consistency of the different models. The interaction of information from different phases can be analysed by comparing the different misfit measures. Structure in the mantle is well resolved except at the base, and ak135 provides a good representation of core velocities. C1 US GEOL SURVEY,DENVER FED CTR,NATL EARTHQUAKE INFORMAT CTR,DENVER,CO 80225. RP KENNETT, BLN (reprint author), AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 0200,AUSTRALIA. OI Kennett, Brian/0000-0003-2206-5350 NR 15 TC 1316 Z9 1356 U1 9 U2 66 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUL PY 1995 VL 122 IS 1 BP 108 EP 124 DI 10.1111/j.1365-246X.1995.tb03540.x PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RG969 UT WOS:A1995RG96900008 ER PT J AU SHOEMAKER, EM HASSIG, PJ RODDY, DJ AF SHOEMAKER, EM HASSIG, PJ RODDY, DJ TI NUMERICAL SIMULATIONS OF THE SHOEMAKER-LEVY-9 IMPACT PLUMES AND CLOUDS - A PROGRESS REPORT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Preliminary 2D/3D numerical simulations were carried out for the penetration of 1-km bodies in the Jovian atmosphere and the subsequent rise and collapse of the erupted plumes. A body that crushed at a stagnation point pressure of 5 kbar produced a plume that rose to 800 km. Evolution of the shape of the calculated plume corresponds rather well to the plumes observed by HST. A crescent-shaped lobe centered on the ''backfire'' azimuth was produced by lateral flow during plume collapse. The plumes observed on Jupiter rose about 4 times higher, and their rise and fall times were about twice those in this calculation. Plume height is a sensitive function of the distribution of energy along the entry path; a very low-strength body will disintegrate higher along the penetration path and will produce a higher plume. C1 TITAN CORP,CHATSWORTH,CA 91311. US GEOL SURVEY,ASTROGEOL BRANCH,FLAGSTAFF,AZ 86001. RP SHOEMAKER, EM (reprint author), LOWELL OBSERV,1400 W MARS HILL RD,FLAGSTAFF,AZ 86001, USA. NR 8 TC 16 Z9 16 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 1995 VL 22 IS 13 BP 1825 EP 1828 DI 10.1029/95GL01775 PG 4 WC Geosciences, Multidisciplinary SC Geology GA RK059 UT WOS:A1995RK05900048 ER PT J AU ANDERSON, WL AF ANDERSON, WL TI Q-FACTOR APPROXIMATION OF ELECTROMAGNETIC-FIELDS FOR HIGH-FREQUENCY SOUNDING IN THE 300 KHZ TO 30 MHZ RANGE OVER LAYERED MEDIA SO GEOPHYSICS LA English DT Note ID IMAGE THEORY C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 15 TC 7 Z9 7 U1 0 U2 0 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD JUL-AUG PY 1995 VL 60 IS 4 BP 1253 EP 1258 DI 10.1190/1.1443856 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RH460 UT WOS:A1995RH46000034 ER PT J AU BURRUSS, RC AF BURRUSS, RC TI OIL AND GAS CD HITS THE CHARTS SO GEOTIMES LA English DT Article RP BURRUSS, RC (reprint author), US GEOL SURVEY,OFF ENERGY & MARINE GEOL,ENERGY RESOURCE SURVEYS PROGRAM,915 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD JUL PY 1995 VL 40 IS 7 BP 14 EP 16 PG 3 WC Geosciences, Multidisciplinary SC Geology GA RG495 UT WOS:A1995RG49500006 ER PT J AU SHAPIRO, AM GREENE, EA AF SHAPIRO, AM GREENE, EA TI INTERPRETATION OF PREMATURELY TERMINATED AIR-PRESSURIZED SLUG TESTS SO GROUND WATER LA English DT Article AB Air-pressurized slug tests offer a means of estimating formation transmissivity and storativity without extensive downhole equipment and in situations where contact with formation fluids may pose a health concern. An air-pressurized slug test, as discussed in this paper, consists of applying a constant pressure to the column of air in a well, monitoring the declining water level, and then releasing the air pressure and monitoring the recovering water level. If the maximum declining (or new equilibrium) water level is achieved for a constant applied air pressure, the slug-test solution of Cooper ct al. (1967) can be used to interpret the water-level recovery data and estimate the formation properties. In low-permeability terranes, the time required to achieve the equilibrium water level during the pressurized part of the test may be too long for practical purposes, and it may be necessary to terminate the applied air pressure prior to establishing a new equilibrium. To analyze data from such tests, a solution to the boundary-value problem for the declining and recovering water level during an air-pressurized slug test is developed for an arbitrary time-dependent air pressure applied to the well. For the special case of applying a constant air pressure and then reducing it instantaneously to atmospheric pressure at a prescribed time, the general solution reduces to the superposition of the solution of Cooper et al. (1967) at two displaced times. Type curves are generated to estimate formation transmissivity and storativity from the recovering water level associated with prematurely terminated air-pressurized slug tests. The application of the type curves is illustrated in tests conducted in wells completed in the Minnelusa and Madison aquifers near Rapid City and Spearfish, South Dakota. C1 US GEOL SURVEY,RAPID CITY,SD 57702. RP SHAPIRO, AM (reprint author), US GEOL SURVEY,431 NATL CTR,RESTON,VA 22092, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 539 EP 546 DI 10.1111/j.1745-6584.1995.tb00308.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000003 ER PT J AU LINDNERLUNSFORD, JB BRUCE, BW AF LINDNERLUNSFORD, JB BRUCE, BW TI USE OF ELECTRIC LOGS TO ESTIMATE WATER-QUALITY OF PRE-TERTIARY AQUIFERS SO GROUND WATER LA English DT Article AB Electric logs provide a means of estimating ground-water quality in areas where water analyses are not available. Most of the methods for interpreting these logs have been developed for the petroleum industry and are most reliable in saline aquifers (concentration of dissolved solids as sodium chloride greater than about 50,000 mg/l). The resistivity-porosity and spontaneous-potential methods were evaluated to determine if they could be applied to identify zones of fresh water (concentration of dissolved solids as sodium chloride less than 1,000 mg/l) in three potential aquifers in central Wyoming. The potential aquifers have different lithologies-sandstone, clayey sandstone, and carbonate. The two methods generally were reliable predictors of water quality in the sandstone and carbonate potential aquifers. In the clayey sandstone potential aquifer, predictions of the dissolved-solids concentration using the two methods differed by more than an order of magnitude in several cases. When the resistivity values are corrected for the presence of clay and shale as identified on a natural gamma log, the agreement between the results of the two methods improved by an average of 58 percent. C1 US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,LAKEWOOD,CO 80215. RP LINDNERLUNSFORD, JB (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,ROCKY MT ARSENAL,COMMERCE CITY,CO 80022, USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 547 EP 555 DI 10.1111/j.1745-6584.1995.tb00309.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000004 ER PT J AU HUNTOON, PW SHOEMAKER, EM AF HUNTOON, PW SHOEMAKER, EM TI ROBERTS RIFT, CANYONLANDS, UTAH, A NATURAL HYDRAULIC FRACTURE CAUSED BY COMET OR ASTEROID IMPACT SO GROUND WATER LA English DT Article AB The impact that created Upheaval crater in Canyonlands National Park, Utah, is invoked here as the source for energy that simultaneously caused Roberts rift. However, no temporal linkage has been proven between the impact and rifting events. Roberts rift lies between 22 and 32 km northeast of the Upheaval impact crater on a subradial trend. The fissure contains clasts that were carried as much as 1,000 m upward from Paleozoic sources into the Mesozoic section. A plausible model for both the rifting and clast movement involves incremental loading of overpressured fluid compartments in the Pennsylvanian Paradox section and attendant hydraulic fracturing of the overlying confining strata during the impact event. The clasts were proppants entrained in upward moving fluids that originated from overpressured aquifers in the Pennsylvanian section or materials eroded from the fissure walls. Alteration halos and mineralization along the fissure reveal that there was upward leakage of reducing fluids from the overpressured zones following opening of the fissure. The fissure infillings became cemented with time, thus reducing fissure permeabilities to negligible. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. RP HUNTOON, PW (reprint author), UNIV WYOMING,DEPT GEOL & GEOPHYS,LARAMIE,WY 82071, USA. NR 10 TC 9 Z9 9 U1 0 U2 4 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 561 EP 569 DI 10.1111/j.1745-6584.1995.tb00311.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000006 ER PT J AU JORGENSEN, DG PETRICOLA, M AF JORGENSEN, DG PETRICOLA, M TI RESEARCH BOREHOLE-GEOPHYSICAL LOGGING IN DETERMINING GEOHYDROLOGIC PROPERTIES SO GROUND WATER LA English DT Article AB A research borehole-geophysical logging program was implemented to assess specific yield, aquifer mineralogy, and water resistivity more accurately and economically than can be done using conventional aquifer testing and coring procedures. The logging program was part of the Ground-Water Research Project for Abu Dhabi Emirate. A method of determining specific yield using data from a thermal decay-time (TDT) log was developed and tested. This technique relates the capture cross section of the fluid in the invaded zone to specific yield. A second new method uses data from density and neutron logs in a program ''LOGAN2'' to determine specific yield. Results from both methods were compared to the specific yield derived from the neutron log as well as a specific yield determined by a complex analysis of data from a set of research borehole-geophysical logs, including a gamma-gamma log for density, neutron, sonic, gamma-ray, induction, microresistivity, photoelectric, caliper, and spontaneous-potential logs. The agreement was good. A method of computer-assisted interpretation of mineralogy was developed by correlating results of direct examination of the mineralogy of sidewall cores with data from a nuclear activated spectral-gamma log (GLT). The GLT log allows the mineralogy to be assessed in a comprehensive manner. These computer interpreted results were used to develop another method of computer-assisted interpretation of holes logged not using the GLT. The second method was applied to the more than 50 other test holes that did not include GLT and TDT logs. Resistivity of the water in the formation was conceptualized using a dual-water model, which is especially suited for clayey aquifers. Water resistivities were calculated by two methods-first using data from the suite of logs without the GLT and again using the data from the research suite of logs, which included the GLT The agreement of calculated water resistivities was excellent. C1 SCHLUMBERGER MIDDLE E,ABU DHABI,U ARAB EMIRATES. RP JORGENSEN, DG (reprint author), US GEOL SURVEY,AL AIN,U ARAB EMIRATES. NR 16 TC 1 Z9 1 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 589 EP 596 DI 10.1111/j.1745-6584.1995.tb00314.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000009 ER PT J AU BACK, W LANDA, ER MEEKS, L AF BACK, W LANDA, ER MEEKS, L TI BOTTLED WATER, SPAS, AND EARLY YEARS OF WATER CHEMISTRY SO GROUND WATER LA English DT Article AB Although hot springs have been used and enjoyed for thousands of years, it was not until the late 1700s that they changed the course of world civilization by being the motivation for development of the science of chemistry. The pioneers of chemistry such as Priestley, Cavendish, Lavoisier, and Henry were working to identify and generate gases, in part, to determine their role in carbonated beverages. In the 18th century, spas in America were developed to follow the traditional activities of popular European spas. However, they were to become a dominant political and economic force in American history on three major points: (1) By far the most important was to provide a place for the leaders of individual colonies to meet and discuss the need for separation from England and the necessity for the Revolutionary War; (2) the westward expansion of the United States was facilitated by the presence of hot springs in many locations that provided the economic justification for railroads and settlement; and (3) the desire for the preservation of hot springs led to the establishment of the National Park Service. Although mineral springs have maintained their therapeutic credibility in many parts of the world, they have not done so in the United States. We suggest that the American decline was prompted by: (1) the establishment of The Johns Hopkins School of Medicine in 1893; (2) enactment of the Pure Food and Drug Act of 1907; and (3) the remarkable achievement of providing safe water supplies for American cities by the end of the 1920s. The current expanding market for bottled water is based in part on bottled water being an alternative beverage to alcohol and sweetened drinks and the inconsistent palatability and perceived health hazards of some tap waters. C1 UNIV ARKANSAS,DEPT GEOL,FAYETTEVILLE,AR 72701. RP BACK, W (reprint author), US GEOL SURVEY,431 JOHN WESLEY POWELL BLDG,RESTON,VA 22092, USA. NR 44 TC 15 Z9 15 U1 1 U2 3 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 605 EP 614 DI 10.1111/j.1745-6584.1995.tb00316.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000011 ER PT J AU MCNEW, ER ARAV, S AF MCNEW, ER ARAV, S TI SURFACE GEOPHYSICAL SURVEYS OF THE FRESH-WATER-SALTWATER INTERFACE IN A COASTAL AREA OF LONG-ISLAND, NEW-YORK SO GROUND WATER LA English DT Article ID TRANSPORT AB The North Fork of Long Island is a peninsula whose freshwater supply consists of several lenses of fresh ground water that are surrounded by saline ground water. A study to determine the thickness of one freshwater lens near the Village of Greenport used two surface-geophysical techniques at several sites to provide ground-conductivity data that were, in turn, used to estimate the depth to the freshwater-saltwater interface. Surveys were made during the spring and fall of 1989. Wells drilled during 1989 provided some verification of geophysical interpretations. Geophysical-data interpretations were based on conceptual models with two, three, and four conductivity layers; the three-layer concept produced interpretations that best matched geophysical measurements at all sites. The surface geophysical techniques were successful in interpreting depth to saline ground water. Interpreted depths to the freshwater-saltwater interface were compared to assess seasonal changes; the interpreted differences were small and within the range of error of the survey techniques. C1 TG HULETT & ASSOCIATES,CARONA,CA 91720. RP MCNEW, ER (reprint author), US GEOL SURVEY,5 AERIAL WAY,SYOSSET,NY 11791, USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 615 EP 626 DI 10.1111/j.1745-6584.1995.tb00317.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000012 ER PT J AU BALES, RC LI, SM MAGUIRE, KM YAHYA, MT GERBA, CP HARVEY, RW AF BALES, RC LI, SM MAGUIRE, KM YAHYA, MT GERBA, CP HARVEY, RW TI VIRUS AND BACTERIA TRANSPORT IN A SANDY AQUIFER, CAPE-COD, MA SO GROUND WATER LA English DT Article ID GRADIENT TRACER TEST; NATURAL-GRADIENT; POROUS-MEDIA; CHEMICAL PERTURBATIONS; MASSACHUSETTS; GRAVEL; FILTRATION; MOVEMENT; MS-2 AB Transport of the bacteriophage PRD-1, bacteria, and latex microspheres was studied in a sandy aquifer under natural-gradient conditions. The field injection was carried out at the U.S. Geological Survey's Toxic Substances Hydrology research site on Cape God. The three colloids and a salt tracer (Br-) moved along the same path. There was significant attenuation of the phage, with PRD-1 peak concentrations less than 0.001 percent of Br- peaks 6 m from the source; but the low detection limit (one per mi) enabled tracking movement of the PRD-1 plume for 12 m downgradient over the 25-day experiment. Attenuation of phage was apparently due to retention on soil particles (adsorption). Attenuation of bacteria and microspheres was less, with peak concentrations 6 m from the source on the order of 10 and 0.4 percent of Br, respectively. Injection of a high-pa pulse of water 20 days into the experiment resulted in significant remobilization of retained phage, demonstrating that attached phage remained viable, and that PRD-1 attachment to and detachment from the sandy soil particles was highly pH dependent. Phage behavior in this experiment, i.e. attenuation at pH 5.7 and rapid resuspension at pH 6-8, was consistent with that observed previously in laboratory column studies. Results illustrate that biocolloids travel in a fairly narrow plume in sandy (relatively homogeneous) media, with virus concentrations dropping below detection limit several meters away from the source; bacteria concentrations above detection limits can persist over longer distances. C1 UNIV ARIZONA,DEPT MICROBIOL & IMMUNOL,TUCSON,AZ 85721. US GEOL SURVEY,DIV WATER RESOURCES,BOULDER,CO 80225. RP BALES, RC (reprint author), UNIV ARIZONA,DEPT HYDROL & WATER RESOURCES,TUCSON,AZ 85721, USA. RI Harvey, Ronald/C-5783-2013 OI Harvey, Ronald/0000-0002-2791-8503 NR 23 TC 103 Z9 104 U1 0 U2 9 PU GROUND WATER PUBLISHING CO PI COLUMBUS PA 2600 GROUND WATER WAY, COLUMBUS, OH 43219 SN 0017-467X J9 GROUND WATER JI Ground Water PD JUL-AUG PY 1995 VL 33 IS 4 BP 653 EP 661 DI 10.1111/j.1745-6584.1995.tb00321.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA RG500 UT WOS:A1995RG50000016 ER PT J AU SAFAK, E AF SAFAK, E TI DISCRETE-TIME ANALYSIS OF SEISMIC SITE AMPLIFICATION SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID GROUND MOTION; EARTHQUAKES; CALIFORNIA AB A discrete-time analysis of seismic site amplification in layered media for vertically propagating shear waves is presented. The discrete-time approach not only is simpler and more accurate than the previously suggested frequency-domain techniques but also provides better physical insight into the problem. The discrete-time domain equations of wave propagation can be derived by using the upgoing and downgoing waves as auxiliary variables, and require only three parameters for each layer: the reflection coefficient at the bottom of the layer, the travel time of waves in the layer, and the damping. The discrete-time formulation results in simple analytical models for site amplification. When compared with the previous ones, these new models have important advantages: (1) They use the physical parameters of the site; (2) for a single soil layer over bedrock subjected to vertically propagating waves, the model is exact; (3) amplitudes and phase characteristics of the site are accounted for in the models; (4) the models can incorporate multiple reflections in the layer; and (5) the models result in simple time-domain filters for simulating ground motions. They also provide convenient tools to develop random vibration models, generate site-specific response spectra, and identify site characteristics from recorded motions. RP SAFAK, E (reprint author), US GEOL SURVEY,MS 966,BOX 25046,DENVER,CO 80225, USA. NR 37 TC 35 Z9 36 U1 0 U2 4 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD JUL PY 1995 VL 121 IS 7 BP 801 EP 909 PG 109 WC Engineering, Mechanical SC Engineering GA RC940 UT WOS:A1995RC94000006 ER PT J AU MAJEWSKI, MS MCCHESNEY, MM WOODROW, JE PRUEGER, JH SEIBER, JN AF MAJEWSKI, MS MCCHESNEY, MM WOODROW, JE PRUEGER, JH SEIBER, JN TI AERODYNAMIC MEASUREMENTS OF METHYL-BROMIDE VOLATILIZATION FROM TARPED AND NONTARPED FIELDS SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID MEASURING PESTICIDE EVAPORATION; WHEAT FIELD; ICE ALGAE; SOIL; TRANSFORMATION; TRIFLURALIN; TRANSPORT; WATER; RATES; FATE AB Methyl bromide (MeBr) is used extensively in agriculture as a soil fumigant and there is growing concern over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and very little is known about how much of the applied fumigant volatilizes into the atmosphere after the application. This held study was designed to estimate the post-application methyl bromide volatilization loss rates from two different application practices. The fields were approximately 6 km apart in Monterey County, California, and were treated in conformity with local practices as of 1992. The MeBr was injected at a depth of 25 to 30 cm. One field was covered simultaneously with a high-barrier plastic film tarp during the application, and the other was left uncovered, but the furrows made by the injection shanks were bedded over. Volatilization fluxes were estimated using an aerodynamic-gradient technique immediately following the completion of the application process and continued for 9 d for the tarped held and 6 d for the nontarped held. The cumulative volatilization losses from the tarped held were 22% of the nominal application within the first 5 d of the experiment and about 32% of the nominal application within 9 d including the one day after the tarp was removed on Day 8 after application. In contrast, the nontarped field lost 89% of the nominal application by volatilization in 5 d. The volatilization rate from the tarped field was shown to be significantly lower than the nontarped field at a 95% confidence level. C1 UNIV CALIF DAVIS,DEPT ENVIRONM TOXICOL,DAVIS,CA 95616. FMC CORP,AGR CHEM GRP,RICHMOND,CA 94801. UNIV NEVADA,CTR ENVIRONM SCI & ENGN,RENO,NV 89557. USDA ARS,NATL SOIL TILTH LAB,AMES,IA 50011. RP MAJEWSKI, MS (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,2800 COTTAGE WAY,ROOM W-2233,SACRAMENTO,CA 95825, USA. NR 43 TC 68 Z9 69 U1 0 U2 1 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JUL-AUG PY 1995 VL 24 IS 4 BP 742 EP 752 PG 11 WC Environmental Sciences SC Environmental Sciences & Ecology GA RJ934 UT WOS:A1995RJ93400025 ER PT J AU TINDALL, JA PETRUSAK, RL MCMAHON, PB AF TINDALL, JA PETRUSAK, RL MCMAHON, PB TI NITRATE TRANSPORT AND TRANSFORMATION PROCESSES IN UNSATURATED POROUS-MEDIA SO JOURNAL OF HYDROLOGY LA English DT Article ID NITROUS-OXIDE PRODUCTION; CALCIUM NITRATE; CLAY SOIL; DENITRIFICATION; LOSSES; NITRIFICATION; LYSIMETER; BALANCE; SLURRY; CROPS AB A series of experiments was conducted on two contrasting agricultural soils to observe the influence of soil texture, preferential flow, and plants on nitrate transport and denitrification under unsaturated conditions. Calcium nitrate fertilizer was applied to the surface of four large undisturbed soil cores (30 cm diameter by 40 cm height). Two of the cores were a structured clay obtained from central Missouri and two were an unstructured fine sand obtained from central Florida. The cores were irrigated daily and maintained at a matric potential of -20 kPa, representative of soil tension in the rooting zone of irrigated agricultural fields. Volumetric water content (theta), concentration of nitrate-N in the soil solution, and nitrous oxide flux at the surface, 10, 20, and 30 cm were monitored daily. Leaching loss of surface-applied NO3--N was significant in both the sand and the clay. In unplanted sand cores, almost all of the applied nitrate was leached below 30 cm within 10 days. Gaseous N loss owing to denitrification was no greater than 2% of the nitrate-N applied to the unplanted sand cores and, in general, was less than 1%. Although leaching was somewhat retarded in the clay cores, about 60% of the applied nitrate-N was leached from the unplanted clay soil in 5-6 weeks. Under unsaturated conditions, the clay had little to no tendency to denitrify despite the greater moisture content of the clay and retarded leaching of nitrate in the clay. The planted sand cores had surprisingly large gaseous N loss owing to denitrification, as much as 17% of the nitrate-N. Results from both the clay and sand experiments show that the dynamics of nitrate transport and transformation in unsaturated soils are affected by small, localized variations in the soil moisture content profile, the gaseous diffusion coefficient of the soil, the rate at which the nitrate pulse passes through the soil, the solubility of N2O and N-2 and the diffusion of the gasses through the soil solution, and development of a water content profile in the soil. Limited denitrification in the clay soil was due to a limited volume of soil available for infiltration after internal catchment and the development of denitrifying conditions resulting from the presence of an extensive macropore system. C1 UNIV COLORADO,DEPT ENVIRONM SCI,DENVER,CO 80217. RP TINDALL, JA (reprint author), US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,MS 413,BOX 25046,DENVER,CO 80225, USA. NR 43 TC 51 Z9 53 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD JUL PY 1995 VL 169 IS 1-4 BP 51 EP 94 DI 10.1016/0022-1694(94)02666-Y PG 44 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RD352 UT WOS:A1995RD35200004 ER PT J AU CAPPELLATO, R PETERS, NE AF CAPPELLATO, R PETERS, NE TI DRY DEPOSITION AND CANOPY LEACHING RATES IN DECIDUOUS AND CONIFEROUS FORESTS OF THE GEORGIA PIEDMONT - AN ASSESSMENT OF A REGRESSION-MODEL SO JOURNAL OF HYDROLOGY LA English DT Article ID INFERENTIAL MEASUREMENT TECHNIQUES; ATMOSPHERIC DEPOSITION; MAJOR IONS; THROUGHFALL; NITROGEN; SULFUR AB Simple and multiple linear regression models were used to estimate dry deposition and canopy leaching sources of constituents in throughfall and stemflow for adjacent deciduous and coniferous forests at the Panola Mountain Research Watershed (PMRW), Georgia. The models were evaluated for their comparability and statistical significance, and model fluxes were compared with fluxes derived from field collection and a dry deposition inferential model, i.e. field-inferred fluxes. The multiple regression model used antecedent dry period and event quantity as independent variables. Field-inferred fluxes indicated that dry deposition was a major source of SO42-, NO3- and H+ in throughfall, and canopy leaching was the major source of Ca2+ Mg2+, K+ and Cl- in both deciduous and coniferous forests. The canopy leaching flux predicted by the multiple linear regression model was: (1) within 30% of the field-inferred fluxes for NH4+ in the deciduous and coniferous forest during the growing season; (2) within 40% of field-inferred fluxes for Ca2+, Mg2+, and K+ in the deciduous forest during the growing season and 50% in the dormant season; (3) within 67% of field-inferred fluxes for H+ in the deciduous forest and Mg2+ and K+ in the coniferous forest. Similarly, dry deposition predicted by multiple linear regression model when compared with the field-inferred flux for the growing season was: (1) the same for Na+ in the deciduous forest; (2) 10% more for Ca2+ in either forest; (3) about 20% less for NH4+ in the deciduous forest; (4) 70% more for Mg2+ in the deciduous forest and K+ in the coniferous forest; (5) 50% less for NH4+ in the coniferous forest; (6) 70% less for SO42- in either forest. The multiple regression model, in general, was best applied to estimate dry deposition and canopy leaching of some constituents for the deciduous forest in the growing season, but it had limited applicability and cannot substitute for field collections for analysis of constituents with significant dry deposition at PMRW. C1 US GEOL SURVEY,ATLANTA,GA 30360. RP CAPPELLATO, R (reprint author), EMORY UNIV,HUMAN & NAT ECOL PROGRAM,ROLLING RES BLDG,1510 CLIFTON RD,ATLANTA,GA 30322, USA. NR 26 TC 28 Z9 35 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD JUL PY 1995 VL 169 IS 1-4 BP 131 EP 150 DI 10.1016/0022-1694(94)02653-S PG 20 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RD352 UT WOS:A1995RD35200007 ER PT J AU REA, DK COLMAN, SM AF REA, DK COLMAN, SM TI RADIOCARBON AGES OF PRE-BOMB CLAMS AND THE HARD-WATER EFFECT IN LAKES MICHIGAN AND HURON SO JOURNAL OF PALEOLIMNOLOGY LA English DT Note ID C-14 AB Five radiocarbon ages, all determined by accelerator mass spectrometry, have been obtained for two pre-bomb bivalves from Lake Michigan and one from Lake Huron. After correcting those ages for the fractionation of C-14 in calcite and for the radioactively inert CO2 in the atmosphere, we find residual ages, caused by the hard water effect, of about 250 years for Lake Michigan and 440 years for Lake Huron. C1 US GEOL SURVEY,WOODS HOLE,MA 02543. RP REA, DK (reprint author), UNIV MICHIGAN,DEPT GEOL SCI,1006 CC LITTLE BLDG,ANN ARBOR,MI 48109, USA. NR 13 TC 23 Z9 24 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-2728 J9 J PALEOLIMNOL JI J. Paleolimn. PD JUL PY 1995 VL 14 IS 1 BP 89 EP 91 DI 10.1007/BF00682596 PG 3 WC Environmental Sciences; Geosciences, Multidisciplinary; Limnology SC Environmental Sciences & Ecology; Geology; Marine & Freshwater Biology GA RQ668 UT WOS:A1995RQ66800006 ER PT J AU HOARE, RD SKIPP, B AF HOARE, RD SKIPP, B TI CALCAREOUS MICROFOSSILS FROM THE UPPER MISSISSIPPIAN (CHESTERIAN) MAXVILLE LIMESTONE, SOUTHEASTERN OHIO SO JOURNAL OF PALEONTOLOGY LA English DT Article AB A low-diversity assemblage of smaller calcareous microfossils is present in the Upper Mississippian Maxville Limestone in Muskingum and Ferry Counties, southeastern Ohio. Diagnostic faunal elements that suggest an early Chesterian age include the foraminifers Neoarchaediscus maxvillensis n. sp., Paraarchaediscus aff. P. Pachytheca (Petryk), Paraarchaediscus cf. P. koktjubensis (Rauzer-Chernousova), Endothyra excellens (Zeller), Endothyra bowmani Phillips emend. Brady, and attached forms. The presence of these diagnostic faunal elements in the Chesterian of Ohio significantly extends their known geographic range into the eastern Midcontinent region. Other forms present include the foraminifers Priscella? of the group P. prisca (Rauzer-Chernousova and Reitlinger), Diplosphaerina inaequalis (Derville), Earlandia spp., and the problematic Asphaltinoides macadami (Brenckle and Groves) and Salebra irregularis Bogush and Brenckle. Microfossils are present in both calcareous mudstone and limestone. C1 US GEOL SURVEY,DENVER,CO 80225. RP HOARE, RD (reprint author), BOWLING GREEN STATE UNIV,DEPT GEOL,BOWLING GREEN,OH 43403, USA. NR 47 TC 2 Z9 2 U1 1 U2 1 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JUL PY 1995 VL 69 IS 4 BP 617 EP 624 PG 8 WC Paleontology SC Paleontology GA RK703 UT WOS:A1995RK70300001 ER PT J AU ADRAIN, JM CHATTERTON, BDE BLODGETT, RB AF ADRAIN, JM CHATTERTON, BDE BLODGETT, RB TI SILURIAN TRILOBITES FROM SOUTHWESTERN ALASKA SO JOURNAL OF PALEONTOLOGY LA English DT Article AB The first Silurian trilobites to be described from Alaska are of late Llandovery (Telychian) age. They occur with original cuticle intact in a white biosparite. Seven species have been identified, including Paracybantyx occidentalis n. sp., Ligiscus smithi n. sp., Calymene s.l. aff. C. iladon Lane and Siveter, 1991, Scotoharpes aff. S. raaschi Norford, 1973, Scharyia sp., a cheirurine belonging to either Radiurus Ramskold, 1983, or Protocerauroides Chatterton and Perry, 1984, and an undetermined warburgelline. The fauna has close affinity to those described from similar lithologies in the Telychian of North Greenland. Machaeridians occurring with the trilobites include Turrilepas sp., Compacoleus sp., and Lepidocoleus cf. L. britannicus Withers, 1926. C1 UNIV ALBERTA,DEPT GEOL,EDMONTON,AB T6G 2E3,CANADA. US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,RESTON,VA 22092. RP ADRAIN, JM (reprint author), UNIV WESTERN ONTARIO,DEPT EARTH SCI,LONDON,ON N6A 5B7,CANADA. NR 55 TC 12 Z9 12 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JUL PY 1995 VL 69 IS 4 BP 723 EP 736 PG 14 WC Paleontology SC Paleontology GA RK703 UT WOS:A1995RK70300010 ER PT J AU CHADWICK, WW DIETERICH, JH AF CHADWICK, WW DIETERICH, JH TI MECHANICAL MODELING OF CIRCUMFERENTIAL AND RADIAL DIKE INTRUSION ON GALAPAGOS VOLCANOS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID DE-LA-FOURNAISE; KILAUEA VOLCANO; ISLANDS; HAWAII; FERNANDINA; STRESSES; PATTERN; REUNION; GROWTH AB A distinctive and unusual pattern of eruptive fissures is observed on the active volcanoes of the Galapagos islands, reflecting circumferential dike intrusion near the calderas and radial dike intrusion on the volcano flanks. Elastic finite-element models were used to investigate how a stress field could be produced and maintained to promote both circumferential and radial dike emplacement. Modeling results show that magma reservoirs of Galapagos volcanoes are probably diapiric, because this shape promotes both circumferential and radial intrusions, but magma pressure alone cannot create the observed pattern of dikes. Loading by volcano growth and magma reservoir pressure could produce a stress field of suitable orientation but insufficient magnitude. The intrusion of circumferential dikes could alter the stress field in a way that promotes future radial diking, and vice versa. Faulting or slumping within the calderas or on the volcano flanks in response to repeated intrusions could also create a stress field conducive to continued intrusion. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP CHADWICK, WW (reprint author), OREGON STATE UNIV,CIMRS,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. NR 48 TC 86 Z9 86 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 37 EP 52 DI 10.1016/0377-0273(94)00060-T PG 16 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800007 ER PT J AU HELIKER, C AF HELIKER, C TI INCLUSIONS IN MOUNT ST-HELENS DACITE ERUPTED FROM 1980 THROUGH 1983 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID SOUTHERN WASHINGTON CASCADES; XENOLITHS; TEXTURES; BASALTS; CYCLES AB Inclusions of plutonic, metavolcanic and volcanic rocks are abundant in dacite pumice and lava from the 1980-1986 eruption sequence at Mount St. Helens. Point counts of inclusions exposed in talus blocks from the dome from 1980 through 1983 show that inclusions form approximately 3.5 vol% of the lava. Eighty-five percent of the inclusions are medium-grained gabbros with an average diameter of 6 cm. Additional rock types include quartz diorite, hornfelsic basalt, dacite, andesite and vein quartz. Disaggregated inclusions are common and define shear planes within the dome. These fragmented inclusions may significantly contaminate analyses of the dacite. The gabbroic inclusions are of four distinct types, all with mineral assemblages consistent with crystallization pressures of less than 9 kb. Textures and major-element compositions indicate that most of the gabbroic inclusions are cumulates. The most abundant inclusion type is laminated gabbronorite, which contains up to 9% interstitial glass, derived from partial melting. The presence of quartz veins and hornblende-bearing veins within sheared zones in the laminated gabbronorite indicates that the source of these inclusions was holocrystalline rock that had been penetrated by water-rich fluids. The gabbronorite contained sufficient water to be susceptible to partial melting when the magma that fed the 1980-1986 eruption sequence was emplaced nearby. Various types of gabbroic inclusions, including the laminated gabbronorite, are common in Mount St. Helens lavas of approximately the last 3000 years. This coincides with the interval, in which Mount St. Helens first erupted basalt and basaltic andesite lavas. These observations, together with the fact that the gabbroic inclusions are compositionally unlike any of the Tertiary intrusive rocks in the Mount St. Helens area, strongly suggest that the inclusions are related to the introduction of basalt to the Mount St. Helens magmatic system. The source of the gabbros could be a layered mafic pluton formed through crystal accumulation from multiple batches of basaltic magma emplaced at mid- to upper-crustal depths beneath the volcano. The prevalence of explosive eruptions at Mount St. Helens may play a part in bringing the inclusions to the surface. The eruptive products of the cataclysmic eruption of May 18, 1980 contain notably fewer inclusions than the pyroclastic flows and dome lavas erupted subsequently. This suggests that the May Is eruption shattered conduit wall rock that was subsequently stoped into the magma and carried to the surface later in the eruption series. RP HELIKER, C (reprint author), US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,POB 51,HAWAII NATL PK,HI 96718, USA. NR 40 TC 28 Z9 28 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 115 EP 135 DI 10.1016/0377-0273(94)00074-Q PG 21 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800012 ER PT J AU DZURISIN, D LOCKWOOD, JP CASADEVALL, TJ RUBIN, M AF DZURISIN, D LOCKWOOD, JP CASADEVALL, TJ RUBIN, M TI THE UWEKAHUNA ASH MEMBER OF THE PUNA BASALT - PRODUCT OF VIOLENT PHREATOMAGMATIC ERUPTIONS AT KILAUEA VOLCANO, HAWAII, BETWEEN 2800 AND 2100 C-14 YEARS AGO SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID EAST RIFT-ZONE; DEPOSITS; SUMMIT AB Kilauea volcano's reputation for relatively gentle effusive eruptions belies a violent geologic past, including several large phreatic and phreatomagmatic eruptions that are recorded by Holocene pyroclastic deposits which mantle Kilauea's summit area and the southeast flank of adjacent Mauna Loa volcano. The most widespread of these deposits whose original distribution can be reconstructed is the Uwekahuna Ash Member of the Puna Basalt, a basaltic surge and fall deposit emplaced during two or more eruptive episodes separated by a few decades to several centuries. The first episode occurred between 2770 +/- 70 and 2265 +/- 50 C-14 yr ago. It included two major pyroclastic surges, each preceded by unusually vigorous lava fountaining from a vent near the volcano's summit. Before the second eruptive episode, 2110 +/- 120 C-14 yr ago, plants had re-colonized the rainforest environment northeast of the summit, and at least two lava flows from Mauna Loa had buried parts of the first-episode deposits. The second episode also began with vigorous lava fountaining, followed by widespread lithic ashfall, a third major surge and finally a fourth fountaining event. Before the final pumice deposit could be significantly reworked, it was partly buried by picritic basalt flows that are unusual in Kilauea's summit area. In proximal areas, the Uwekahuna Ash Member is more than 1 m thick (locally >5 m) and includes lithic blocks up to 0.8 m in diameter. Coarse, primarily lithic debris was deposited around the vent by laterally expanding surges; fallout deposits accumulated preferentially to the northeast under the influence of high-altitude counter-tradewinds. The area devastated by surges and originally buried by at least 15 cm of the Uwekahuna was about 420 km(2). The bulk volume of the deposits was approximately 0.3 km(3), including less than 0.1 km(3) of juvenile material. Juvenile constituents are olivine-tholeiitic basalts similar in major-element composition to typical Kilauea summit lava flows, but variations in both major elements and trace elements suggest that the eruptions tapped more than a single, uniform source region. We infer that the eruptions which produced the Uwekahuna were driven by water interacting with a fluctuating magma column. Magma withdrawal episodes may have been accompanied by large-volume submarine effusive eruptions and by summit collapse. The volume, extent and character of the Uwekahuna deposits underscore the hazards posed by relatively infrequent but potentially devastating explosive eruptions at Kilauea, as well as at other basaltic volcanoes. C1 US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HI 96718. US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. US GEOL SURVEY,RESTON,VA 22092. RP DZURISIN, D (reprint author), US GEOL SURVEY,DAVID A JOHNSTON CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 45 TC 38 Z9 38 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 163 EP 184 DI 10.1016/0377-0273(94)00062-L PG 22 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800015 ER PT J AU PIERSON, TC AF PIERSON, TC TI FLOW CHARACTERISTICS OF LARGE ERUPTION-TRIGGERED DEBRIS FLOWS AT SNOW-CLAD VOLCANOS - CONSTRAINTS FOR DEBRIS-FLOW MODELS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT-ST-HELENS; 13 NOVEMBER 1985; NEVADO-DEL-RUIZ; LAHARS; WASHINGTON; FLOODS; SEDIMENTOLOGY; COLOMBIA AB Theoretical modelling is not yet adequate to predict the behavior of debris flows, which can be an extremely hazardous hydrologic process commonly associated with volcanic eruptions, particularly at snow-clad stratovolcanoes. To provide a realistic basis for modelling the behavior of large (> 1000 m(3)/s) debris flows, this paper summarizes kinematic, volumetric and hydraulic characteristics of ten large historic volcanic debris flows from four different volcanoes. Although debris flows larger than these are known to have occurred in the past, the ten summarized here define a practical upper range in magnitude of more typical flows to be considered for future hazard prediction. Peak flow velocities of the ten debris flows studied were indirectly measured to be between about 5 and 20 m/s on gradients of 0.005 to 0.25 m/m, but locally they were as great as 40 m/s. Hydraulic (average) depths were as great as 25 m, but were more commonly between 5 and 15 m in channels up to 400 m wide. Computed peak discharges (volumetric flow rates) were as high as 10(5) m(3)/s, and total volumes were as much as 10(8) m(3). Total flow volumes increased by as much as four times in relatively steep channels as eroded sediment was incorporated into the debris flows. Flows generally achieved supercritical flow and deposited minimal volumes of sediment on gradients steeper than 0.02 m/m. Subcritical flow and active deposition predominated on gradients less than 0.01 m/m, although flows travelled tens of kilometers on such low gradients while laying down deposits. Total distances travelled (as debris flows) were as far as 120 km. RP PIERSON, TC (reprint author), US GEOL SURVEY, CASCADES VOLCANO OBSERV, 5400 MACARTHUR BLVD, VANCOUVER, WA 98661 USA. NR 71 TC 62 Z9 62 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 283 EP 294 DI 10.1016/0377-0273(94)00070-W PG 12 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800023 ER PT J AU IVERSON, RM AF IVERSON, RM TI CAN MAGMA-INJECTION AND GROUNDWATER FORCES CAUSE MASSIVE LANDSLIDES ON HAWAIIAN VOLCANOS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID KILAUEA VOLCANO; FLOW; FAILURE; AVALANCHE; BENEATH; SLOPES AB Landslides with volumes exceeding 1000 km(3) have occurred on the flanks of Hawaiian volcanoes. Because the flanks typically slope seaward no more than 12 degrees, the mechanics of slope failure are problematic. Limit-equilibrium analyses of wedge-shaped slices of the volcano flanks show that magma injection at prospective headscarps might trigger the landslides, but only under very restrictive conditions. If static magma weight is the sole source of magma pressure, hypothetical flank failures can have any size, but can occur only if slip-surface friction angles are less than about 16 degrees. If slip surfaces have friction angles more typical of fragmented or intact rocks (30-40 degrees), flank failures can occur only if mean magma pressures exceed static equilibrium pressures. Landslide length then scales with the excess magma pressure divided by the buoyant unit weight of the volcano flank. For typical excess magma pressures, buoyant unit weights and rock friction angles, the largest landslides that might be triggered in this manner have lengths of only several kilometers. This is at least an order of magnitude too small to explain the occurrence of giant Hawaiian landslides. The growing mass of active Hawaiian volcanoes can compress the edifice and substrate rocks and consequently produce groundwater head gradients that might destabilize larger sectors of the volcano flanks. However, calculations show that volcano growth at an estimated long-term vertical rate of 0.02 m/yr can generate significant head gradients only if an areally extensive, buried clay layer exists that has a great thickness ( similar to 200 m) or very low hydraulic diffusivity ( similar to 10(-11) m(2)/s). Additional calculations show that groundwater head gradients associated with topographically induced flow and sea-level change are less likely to be important. Thus a simple, quantitative explanation for failure of Hawaiian volcano flanks remains elusive, and more complex scenarios may merit investigation. RP IVERSON, RM (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 51 TC 86 Z9 86 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 295 EP 308 DI 10.1016/0377-0273(94)00064-N PG 14 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800024 ER PT J AU VALLANCE, JW SIEBERT, L ROSE, WI GIRON, JR BANKS, NG AF VALLANCE, JW SIEBERT, L ROSE, WI GIRON, JR BANKS, NG TI EDIFICE COLLAPSE AND RELATED HAZARDS IN GUATEMALA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID VOLCANO; ERUPTION; FUEGO; AVALANCHES; COMPLEX; HISTORY AB Guatemalan volcanoes have at least seven debris-avalanche deposits, associated with Cerro Quemado, Fuego, Pacaya, Tecuamburro and an unidentified volcano. The deposits range in size from less than 0.1 to in excess of 9 km(3) and from 2.5 to in excess of 300 km(2). The avalanches traveled 3 to 50 km from their sources in the Guatemalan highlands. Three of the avalanches occurred in Late Pleistocene time and four in Holocene time-two of them within the last 2000 years, The avalanches occurred at both andesitic and basaltic stratovolcanoes and at dacitic dome complexes, Laterally directed phreatic or magmatic pyroclastic explosions were associated with two of the debris avalanches. An evaluation of factors that might lead to an edifice collapse in Guatemala is based on the case studies presented in this report and a survey of the literature. Edifice collapses are more apt to occur if zones of weakness exist within the volcanic edifices, such as unwelded pyroclastic rocks and pervasively altered rocks, Further, the trench-ward side of volcano pairs like Fuego and Atitlan may be more likely to fail because it may have weak zones along the contact with the older back-are volcano. The direction of failure may be influenced by regional slopes, which in Guatemala generally trend southward toward the oceanic trench, and by such structural factors as multiple vents or overly steep slopes reflecting previous activity or erosion, Debris avalanches are more likely to occur in drainages which have headwaters at two or more volcanoes, Domes ate especially apt to produce small- to moderate-sized debris avalanches, and, further, if the domes form a coalescing chain, are most likely to fail in a direction normal to the chain. These factors are used at seventeen major volcanic centers in Guatemala to assess their potential for edifice collapse and most probable direction of failure. C1 SMITHSONIAN INST,GLOBAL VOLCANISM PROGRAM,WASHINGTON,DC 20560. INSIVUMEH,SECC VULCANOL,GUATEMALA CITY,GUATEMALA. US GEOL SURVEY,VANCOUVER,WA 98661. RP VALLANCE, JW (reprint author), MICHIGAN TECHNOL UNIV,DEPT GEOL ENGN & SCI,HOUGHTON,MI 49931, USA. RI Rose, William/A-7923-2009 NR 47 TC 46 Z9 47 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 337 EP 355 DI 10.1016/0377-0273(94)00076-S PG 19 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800026 ER PT J AU SIEBERT, L BEGET, JE GLICKEN, H AF SIEBERT, L BEGET, JE GLICKEN, H TI THE 1883 AND LATE-PREHISTORIC ERUPTIONS OF AUGUSTINE VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT-ST-HELENS; DEBRIS AVALANCHES; DEPOSITS; WASHINGTON; FLOW; STRATIGRAPHY; CHRONOLOGY; CREEK AB The eruptive history of Augustine volcano has been characterized by cycles of growth and destruction of the volcano. Repeated failure of 5-10% of the edifice has produced mobile debris avalanches that reached the sea on all sides. High lava extrusion rates rapidly restore the volcano to its pre-failure configuration. This equilibrium between constructive and destructive processes has resulted in a relatively low lava-dome complex surrounded by an apron of volcaniclastic debris three times the volume of the dome complex. The most recent edifice collapse occurred in 1883, producing the 0.3 km(3) Purr Point debris-avalanche deposit. Three major slide blocks extended the shoreline up to 2 km and produced a tsunami that swept across Cook Inlet. Hummock morphologies change from a proximal radial orientation to a dominantly transverse alignment reflecting deceleration and compression of the avalanches as they enter the sea. The breached crater formed by collapse was then largely filled by a 0.09 km(3) lava dome and a 0.04 km(3) lava flow travelled down the north flank. Lithic block-and-ash flows and pyroclastic surges reached the coast. The Burr Point avalanche deposit partially overlaps the Rocky Point debris-avalanche deposit to the west that was probably emplaced 200-400 years B.P. A major collapse event at ca. 1540 +/- 110 A.D. produced the West Island debris avalanche, ending a period of expansion of the western side of the island. An accompanying lateral blast overtopped the avalanche, covering a 40 degrees sector of the west flank. The plinian tephra layer B may also have been erupted at the time of the West Island eruption. Today Augustine volcano has rebuilt itself to a size similar to that which preceded the last edifice failure in 1883. The frequency of past collapses (three in the last 500 years) suggests that summit collapse is a possibility during any future eruption. The next major collapse is expected to involve 0.1-0.5 km(3) of the summit; the ensuing debris avalanche would likely reach the coast, producing a tsunami that could impact populated areas of the Kenai Peninsula. The largest tsunami would result from collapse in directions other than to the north or west. Tsunami magnitude is contingent on failure volume, direction and timing with respect to tides. C1 UNIV ALASKA FAIRBANKS,DEPT GEOL & GEOPHYS,FAIRBANKS,AK 99775. UNIV ALASKA FAIRBANKS,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775. RP SIEBERT, L (reprint author), SMITHSONIAN INST,GLOBAL VOLCANISM PROGRAM,WASHINGTON,DC 20560, USA. NR 68 TC 41 Z9 41 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP 367 EP 395 DI 10.1016/0377-0273(94)00069-S PG 29 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800028 ER PT J AU MOORE, JG AF MOORE, JG TI GLICKEN,HARRY AT COLDWATER-2 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Editorial Material RP MOORE, JG (reprint author), US GEOL SURVEY,POB 51,HAWAII NATL PK,HI 96718, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP R15 EP R16 PG 2 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800003 ER PT J AU SWANSON, DA AF SWANSON, DA TI GLICKEN,HARRY 1958-1991 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Item About an Individual RP SWANSON, DA (reprint author), US GEOL SURVEY,POB 51,HAWAII NATL PK,HI 96718, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 1995 VL 66 IS 1-4 BP R12 EP R14 PG 3 WC Geosciences, Multidisciplinary SC Geology GA RU458 UT WOS:A1995RU45800002 ER PT J AU FEDYNICH, AM PENCE, DB GODFREY, RD AF FEDYNICH, AM PENCE, DB GODFREY, RD TI HEMATOZOA IN THIN BLOOD SMEARS SO JOURNAL OF WILDLIFE DISEASES LA English DT Letter ID WILD TURKEYS; TRANSMISSION; PARASITES; ANATIDS; FLORIDA; BIRDS C1 US FISH & WILDLIFE SERV,MCFADDEN NATL WILDLIFE REFUGE,SABINE PASS,TX 77655. RP FEDYNICH, AM (reprint author), TEXAS TECH UNIV,HLTH SCI CTR,DEPT PATHOL,3601 4TH ST,LUBBOCK,TX 79430, USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JUL PY 1995 VL 31 IS 3 BP 436 EP 438 PG 3 WC Veterinary Sciences SC Veterinary Sciences GA RK432 UT WOS:A1995RK43200028 PM 8592373 ER PT J AU SMITH, DR REINECKE, KJ CONROY, MJ BROWN, MW NASSAR, JR AF SMITH, DR REINECKE, KJ CONROY, MJ BROWN, MW NASSAR, JR TI FACTORS AFFECTING VISIBILITY RATE OF WATERFOWL SURVEYS IN THE MISSISSIPPI ALLUVIAL VALLEY SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE AERIAL SURVEY; MISSISSIPPI ALLUVIAL VALLEY; MONITORING ABUNDANCE; ORDINATING POWER; POPULATION INDEX; VISIBILITY BIAS; WINTERING WATERFOWL ID AERIAL SURVEYS; BIAS; MALLARDS; DUCKS AB Because visibility bias can confound attempts to detect changes in abundance, we evaluated factors that affect visibility rate in aerial surveys of wintering waterfowl. We placed waterfowl decoys in 32 2- x 0.25-km strip transects in the Mississippi Alluvial Valley (MAV) during February 1990 and 1991 and observed the decoys under different experimental conditions. Visibility rate was influenced (P < 0.10) by habitat, transect width, and decoy group size. We simulated variation in use of habitat and found that changes in use between open and wooded wetlands would cause changes in visibility rate and affect the power to detect a change in abundance. The effect of changes in visibility rate on likelihood of detecting population change depended on the magnitude and direction of population change and precision of the population index. For transect surveys of wintering ducks in the MAV we recommend reducing transect width from 250 to 150 m on each side of the aircraft and restricting comparisons between years when greater than or equal to 70% of the population is likely to be distributed in open wetlands. Improved techniques for estimating abundance of wintering waterfowl are also needed so use of questionable population indices can be avoided. C1 UNIV GEORGIA,WARNELL SCH FOREST RESOURCES,GEORGIA COOPERAT FISH & WILDLIFE RES UNIT,ATHENS,GA 30602. NATL BIOL SERV,SO SCI CTR,VICKSBURG,MS 39180. US FISH & WILDLIFE SERV,NATL WETLANDS RES CTR,VICKSBURG,MS 39180. NR 40 TC 17 Z9 17 U1 1 U2 5 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JUL PY 1995 VL 59 IS 3 BP 515 EP 527 DI 10.2307/3802458 PG 13 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA RH455 UT WOS:A1995RH45500012 ER PT J AU TATE, CM BROSHEARS, RE MCKNIGHT, DM AF TATE, CM BROSHEARS, RE MCKNIGHT, DM TI PHOSPHATE DYNAMICS IN AN ACIDIC MOUNTAIN STREAM - INTERACTIONS INVOLVING ALGAL UPTAKE, SORPTION BY IRON-OXIDE, AND PHOTOREDUCTION SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID PHOSPHORUS DYNAMICS; RETENTION; ECOSYSTEM; GROWTH AB Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate ((PO4)-P-32) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed P-32, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of P-32 mass(-1) of algae were typically 10-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of P-32 increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of (PO4)-P-32 from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO4 sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction. RP TATE, CM (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 415,LAKEWOOD,CO 80225, USA. OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 25 TC 50 Z9 53 U1 0 U2 7 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 1995 VL 40 IS 5 BP 938 EP 946 PG 9 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA RQ088 UT WOS:A1995RQ08800010 ER PT J AU CACCHIONE, DA DRAKE, DE KAYEN, RW STERNBERG, RW KINEKE, GC TATE, GB AF CACCHIONE, DA DRAKE, DE KAYEN, RW STERNBERG, RW KINEKE, GC TATE, GB TI MEASUREMENTS IN THE BOTTOM BOUNDARY-LAYER ON THE AMAZON SUBAQUEOUS DELTA SO MARINE GEOLOGY LA English DT Article ID SUSPENDED SEDIMENT STRATIFICATION; SCOTIAN CONTINENTAL RISE; STEADY-STATE; COMBINED WAVE; SHELF; RIVER; MORPHOLOGY; CALIFORNIA; BEDFORMS; VELOCITY AB An instrumented bottom tripod (GEOPROBE) recorded flow and suspended sediment data in the bottom boundary layer above the lower foresets of the Amazon subaqueous delta in 65 m mean water depth in February, 1990. After about two weeks of operation the apparent seafloor at the tripod site rapidly elevated over a 14-hour period by about 44 cm. This sudden change, which was detected by an acoustic altimeter and which caused the loss of signals from the lowermost GEOPROBE current and optical sensors, is thought to have been caused by the incursion of a dense bottom layer of fluid mud that migrated downslope from shallower sections of the foresets. The fluid-mud migration across the outer part of the foresets, if a repetitive and occasional process in this region, could be a major mechanism for episodic seaward growth of the delta. Current velocity profiles are used to estimate shear velocities, u*, and roughness lengths, z(0), during the first two weeks of measurements. The extremely energetic semi-diurnal tidal motion required correction of the estimates of u* and z(0) for acceleration. Average values of u*, and z(0) for the two-week period were 1.7 cm/s and 0.3 cm, respectively. The effects of strong stratification due to flocculated, near-bottom suspended sediment on the estimates of u* are significant for the lower values of u* (u* <1 cm/s). C1 US GEOL SURVEY,MENLO PK,CA 94025. UNIV WASHINGTON,SCH OCEANOG,SEATTLE,WA 98195. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. NR 62 TC 60 Z9 61 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD JUL PY 1995 VL 125 IS 3-4 BP 235 EP 257 DI 10.1016/0025-3227(95)00014-P PG 23 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA RT489 UT WOS:A1995RT48900004 ER PT J AU LANTOS, M ELSTON, DP AF LANTOS, M ELSTON, DP TI LOW-AMPLITUDE TO HIGH-AMPLITUDE OSCILLATIONS AND SECULAR VARIATION IN A 1.2 KM LATE MIOCENE INCLINATION RECORD SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article ID ALTERNATING-FIELD DEMAGNETIZATION; MAGNETITE; SEDIMENTS; ROCK; MAGNETIZATION; TEMPERATURE; CORE AB A Miocene section of 2 km thickness was continuously cored near Szombathely, NW Hungary. A detailed magnetostratigraphic study has been integrated with results of lithologic, sedimentologic, and paleontologic studies. Progressive alternating field (a.f.) and thermal demagnetization, and rock magnetic and mineralogic studies indicate that the natural remanent magnetization (NRM) resides in magnetite and the strata contain only minor secondary magnetizations. Major polarity zones have been defined by inclinations and correlated with the geomagnetic polarity time scale for the interval 10-9 Ma. Inclinations for samples collected at 1/2 m intervals display fine-scale oscillations representing secular variation with period times of 400-700 years. Fluctuating amplitudes of oscillation range from low (less than 10 degrees peak-to-peak) to high (more than 40 degrees), reflecting apparently varying stabilities of the geomagnetic field. Additionally, amplitudes of oscillation progress from low to high, and return to low, forming oscillation cycles with a periodicity of 6.2 +/- 1.8 kyr. The oscillations and boundaries of oscillation cycles are generally unrelated to lithology and stratigraphy. Many oscillation cycles appear to be incomplete and 'interrupted' by high-level oscillations. Some incomplete cycles appear to arise from brief interruptions to the depositional record, whereas other interruptions may irregularly arise from a separate component of the geomagnetic field. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. RP LANTOS, M (reprint author), HUNGARIAN GEOL INST,STEFANIA UT 14,POB 106,H-1442 BUDAPEST,HUNGARY. NR 31 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD JUL PY 1995 VL 90 IS 1-2 BP 37 EP 53 DI 10.1016/0031-9201(95)03017-Q PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF380 UT WOS:A1995RF38000003 ER PT J AU ROJSTACZER, S DEVEREL, SJ AF ROJSTACZER, S DEVEREL, SJ TI LAND SUBSIDENCE IN DRAINED HISTOSOLS AND HIGHLY ORGANIC MINERAL SOILS OF CALIFORNIA SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article AB This study was conducted to determine historical trends in subsidence in the Sacramento-San Joaquin Delta and their environmental controls. Historical subsidence was determined by measuring soil surface elevation loss near electrical tower foundations and by evaluating survey data between 1922 and 1981. The data indicated that subsidence slowed with time, In the western Delta, average subsidence rates were 2.3 cm yr(-1) from 1910 to 1988 and 1.5 cm yr(-1) from 1952 to 1988. Spatially variability in subsidence was correlated with organic matter content of the soil (r(2) = 0.62), which in turn was related to the depositional and drainage history of the Delta. Subsidence rates appeared to be independent of crops grown. C1 US GEOL SURVEY,DIV WATER RESOURCES,SACRAMENTO,CA 95825. RP ROJSTACZER, S (reprint author), DUKE UNIV,DEPT GEOL,BOX 90230,DURHAM,NC 27708, USA. NR 16 TC 22 Z9 23 U1 1 U2 6 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JUL-AUG PY 1995 VL 59 IS 4 BP 1162 EP 1167 PG 6 WC Soil Science SC Agriculture GA RJ797 UT WOS:A1995RJ79700031 ER PT J AU MENG, L MOYLE, PB AF MENG, L MOYLE, PB TI STATUS OF SPLITTAIL IN THE SACRAMENTO-SAN-JOAQUIN ESTUARY SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID STRIPED BASS; MORONE-SAXATILIS; LIFE-HISTORY; RIVER FLOW; CALIFORNIA; ABUNDANCE; FISHES AB Analysis of data from four extensive fish surveys in the Sacramento-San Joaquin estuary indicated that splittail Pogonichthys macrolepidotus, endemic to the Central Valley of California, declined by 62% over a 13-year period. Splittails are now found mostly in the estuary, a fraction of their former range. In a gill-net survey in August 1994, 50% of the splittails taken in the estuary were from the Suisun Bay area, and 50% were just upstream in shallow, well-vegetated areas. Splittails migrate into freshwater to spawn, and river outflow carries juveniles into productive, shallow, low-salinity areas downstream. The high correlation of abundance of young with river outflow (average r(2), 0.60) and a weak stock-recruitment relationship (r(2) = 0.22) indicate that spawning success depends on favorable environmental conditions created by high outflows, such as the number of days that lowland areas remain flooded in the spring. A repeated measures analysis of variance indicated that splittails prefer shallow, low-salinity habitats. The reductions in splittail abundance and range and the movements and habitat preferences of splittail young and adults correspond to trends and habits of two other species characteristic of the estuary, delta smelt Hypomesus transpacificus and longfin smelt Spirinchus thaleichthys. The largest threats to these three species are changes in water management and increases in water diversions that reduce spawning and rearing areas and other low-salinity habitats in Suisun Bay. C1 UNIV CALIF DAVIS,DAVIS,CA 95616. RP MENG, L (reprint author), US FISH & WILDLIFE SERV,SACRAMENTO FIELD OFF,2800 COTTAGE WAY,ROOM 1803,SACRAMENTO,CA 95825, USA. NR 23 TC 31 Z9 32 U1 0 U2 3 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JUL PY 1995 VL 124 IS 4 BP 538 EP 549 DI 10.1577/1548-8659(1995)124<0538:SOSITS>2.3.CO;2 PG 12 WC Fisheries SC Fisheries GA RK641 UT WOS:A1995RK64100005 ER PT J AU REBAR, AH LIPSCOMB, TP HARRIS, RK BALLACHEY, BE AF REBAR, AH LIPSCOMB, TP HARRIS, RK BALLACHEY, BE TI CLINICAL AND CLINICAL LABORATORY CORRELATES IN SEA OTTERS DYING UNEXPECTEDLY IN REHABILITATION CENTERS FOLLOWING THE EXXON-VALDEZ OIL-SPILL SO VETERINARY PATHOLOGY LA English DT Article DE EXXON VALDEZ; OIL; SEA OTTERS ID CRUDE-OIL; LESIONS AB Following the Exxon Valdez oil spill, 347 oiled sea otters (Enhydra lutris) were treated in rehabilitation centers. Of these, 116 died, 94 within 10 days of presentation. Clinical records of 21 otters dying during the first 10 days of rehabilitation were reviewed to define the laboratory abnormalities and clinical syndromes associated with these unexpected deaths. The most common terminal syndrome was shock characterized by hypothermia, lethargy, and often hemorrhagic diarrhea. In heavily and moderately oiled otters, shock developed within 48 hours of initial presentation, whereas in lightly oiled otters shock generally occurred during the second week of captivity. Accompanying laboratory abnormalities included leukopenia with increased numbers of immature neutrophils (degenerative left shift), lymphopenia, anemia, azotemia (primarily prerenal), hyperkalemia, hypoproteinemia/hypoalbuminemia, elevations of serum transaminases, and hypoglycemia. Shock associated with hemorrhagic diarrhea probably occurred either as a direct primary effect of oiling or as an indirect effect secondary to confinement and handling in the rehabilitation centers. Lightly oiled otters were less likely to die from shock than were heavily oiled otters (22% vs. 72%, respectively). Heavily oiled otters developed shock more rapidly and had greater numbers of laboratory abnormalities, suggesting that exposure to oil was an important contributing factor. C1 ARMED FORCES INST PATHOL,WASHINGTON,DC 20306. US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. RP REBAR, AH (reprint author), PURDUE UNIV,SCH VET MED,1240 LYNN HALL,W LAFAYETTE,IN 47907, USA. NR 10 TC 12 Z9 12 U1 0 U2 8 PU AMER COLL VET PATHOLOGIST PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0300-9858 J9 VET PATHOL JI Vet. Pathol. PD JUL PY 1995 VL 32 IS 4 BP 346 EP 350 PG 5 WC Pathology; Veterinary Sciences SC Pathology; Veterinary Sciences GA RH947 UT WOS:A1995RH94700002 PM 7483208 ER PT J AU WANG, WC LISZEWSKI, M BUCHMILLER, R CHERRYHOLMES, K AF WANG, WC LISZEWSKI, M BUCHMILLER, R CHERRYHOLMES, K TI OCCURRENCE OF ACTIVE AND INACTIVE HERBICIDE INGREDIENTS AT SELECTED SITES IN IOWA SO WATER AIR AND SOIL POLLUTION LA English DT Article ID ATRAZINE; SOIL AB The objective of this study was to investigate the occurrence of herbicide active and inactive ingredients (primarily volatile organic compounds) at four selected sites in Iowa representing drain tiles, observation wells, or lysimeters. Water samples were collected monthly and bi-monthly before and after herbicide applications in 1991, respectively. They were analyzed for seven herbicides and 32 volatile organic compounds using methods recommended by the U.S. Environmental Protection Agency. Commercially available herbicide formulations also were obtained and analyzed for volatile organic compounds. Herbicides were detected in 50% of water samples, ranging from 78% of water samples from the Ames site to 25% from the Walnut Creek site. Among herbicides detected, listed in decreasing order of frequency, were atrazine > alachlor > cyanazine > metolachlor > metribuzin. Volatile organic compounds were detected in 11% of water samples. Among the compounds detected, listed in decreasing order of frequency, were xylene > toluene > acetone. One sample contained a detectable amount of aliphatic compound(s), with the empirical formula of C8H18. Results from the Deer Creek site showed that herbicides were detected primarily in the top layer (1.2 m), whereas xylene and other alkylbenzenes were detected at 2.1 m or deeper. Apparently, physico-chemical and other factors are separating herbicides and volatile organic compounds in the shallow unsaturated zone. C1 US GEOL SURVEY,IOWA CITY,IA 52240. UNIV IOWA,HYG LAB,IOWA CITY,IA 52242. NR 25 TC 4 Z9 4 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD JUL PY 1995 VL 83 IS 1-2 BP 21 EP 35 DI 10.1007/BF00482591 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA RX314 UT WOS:A1995RX31400002 ER PT J AU MCCABE, GJ AF MCCABE, GJ TI RELATIONS BETWEEN WINTER ATMOSPHERIC CIRCULATION AND ANNUAL STREAMFLOW IN THE WESTERN UNITED-STATES SO CLIMATE RESEARCH LA English DT Article DE STREAMFLOW; WESTERN UNITED STATES; ATMOSPHERIC CIRCULATION ID MONTHLY MEAN CIRCULATION; MONTHLY PRECIPITATION; SCALE CIRCULATION; HEIGHT FIELD; TEMPERATURE; CLIMATE; MODEL; SPECIFICATION; JANUARY AB Winter mean 700 millibar (700 mb) height anomalies, representing the average atmospheric circulation during the snow season, were compared with annual streamflow measured at 140 stream gauges in the western United States, Correlation analysis was used to identify relations between winter mean atmospheric circulation and annual streamflow, and to quantify the degree to which the temporal variability in annual streamflow can be attributed to variations in winter mean atmospheric circulation. Results indicate that winter mean 700 mb height anomalies account for a statistically significant portion of the temporal variability in annual streamflow in the western United States. In general, above-average annual streamflow is associated with negative winter mean 700 mb height anomalies over the eastern North Pacific Ocean and/or the western United States. These anomalies are indicative of anomalous cyclonic circulation which is associated with an anomalous flow of moist air from the eastern North Pacific Ocean into the western United States that increases winter precipitation and snowpack accumulations, and subsequently streamflow. Below-average annual streamflow is associated with positive 700 mb height anomalies over the eastern North Pacific Ocean and/or the western United States. These positive anomalies indicate anomalous anticyclonic circulation which prevents the intrusion of moist air from the eastern North Pacific Ocean into the western United States, increases subsidence, decreases winter precipitation, and results in decreased streamflow. Results also indicate that long-term trends in annual streamflow are related to long-term trends in winter mean 700 mb height anomalies. RP MCCABE, GJ (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 412,DENVER,CO 80225, USA. NR 43 TC 2 Z9 2 U1 0 U2 2 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0936-577X J9 CLIMATE RES JI Clim. Res. PD JUN 22 PY 1995 VL 5 IS 2 BP 139 EP 148 DI 10.3354/cr005139 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA RQ667 UT WOS:A1995RQ66700005 ER PT J AU LOFERSKI, PJ AYUSO, RA AF LOFERSKI, PJ AYUSO, RA TI PETROGRAPHY AND MINERAL CHEMISTRY OF THE COMPOSITE DEBOULLIE PLUTON, NORTHERN MAINE, USA - IMPLICATIONS FOR THE GENESIS OF CU-MO MINERALIZATION SO CHEMICAL GEOLOGY LA English DT Article ID HYDROXYL EXCHANGE; BIOTITE; APATITE; CL; GEOTHERMOMETER; CALIFORNIA; AMPHIBOLES; FELDSPARS; PETROLOGY; FLUORINE AB Biotite and apatite mineral chemistry, particularly halogen abundances and ratios, are used to investigate the relation of the two contrasting parts of the Deboullie composite pluton (syenite-granodiorite) located in northern Maine. Biotite mineral chemistry helps to classify the weakly developed porphyry-style mineralization (Cu-Mo) associated with syenitic rocks of the Deboullie pluton. Unmineralized syenite consists of K-feldspar + plagioclase + quartz + biotite + homblende +/- clinopyroxene and minor amounts of apatite, titanite, magnetite, zircon and allanite. Biotite and apatite occur within the matrix of the rocks and within small multiphase inclusions hosted by clinopyroxene. The inclusions are interpreted to be crystallized melt inclusions rather than solid inclusions, that were trapped by clinopyroxene during growth. The multiphase inclusions consist of K-feldspar + quartz + biotite + apatite + magnetite. The F contents of biotite display a strong positive correlation with the phlogopite component, or Xphl [Xphl = Mg/(sum octahedral cations)]. Biotites from the multiphase inclusions have higher F contents and higher values of F/ (F + Cl + OH) and Xphl than biotites in the matrix that presumably formed later during crystallization and/or re-equilibrated with late-stage fluids. Contents of Ti02, largely overlap for the inclusion and matrix biotite. Apatite compositions plot within the fluorapatite field [F/ (F + Cl + OH) = 0.57-0.99]. Apatites in the multiphase inclusions have higher Cl contents than apatites in the matrix or those enclosed in biotite. Biotite-apatite geothermometry for the multiphase inclusions yields magmatic or near-magmatic temperatures (725-850 degrees C); biotite-apatite pairs outside the inclusions yield temperatures that range from near-magmatic (600-775 degrees C) to much lower ( < 450 degrees C), again indicating low-temperature re-equilibration or disequilibrium alteration. The relation between (XF/XCl) and Xphl was used to infer HF/HC1 fugacity ratios in associated hydrothermal fluids, and indicates that biotite from the Deboullie pluton is strikingly similar to biotite from the porphyry-Cu deposit at Santa Rita, New Mexico, but distinctly different from biotite from the porphyry-Mo deposit at Henderson, Colorado. The assemblage quartz + magnetite + titanite implies an oxidation state for the Deboullie pluton well above the quartz-magnetite-fayalite buffer, which is also consistent with magmas associated with porphyry-Cu deposits. On a regional scale, biotite compositions from,granitic plutons in Maine do not vary in a systematic manner. This implies that biotite compositions no longer directly reflect source compositions, Finally, biotite and apatite compositions of the syenite and granodiorite are different; compositional ranges in the granodiorite are more restricted than those in the syenite. This provides evidence that the two parts of this composite pluton had different origins and are not related by crystal fractionation. RP LOFERSKI, PJ (reprint author), US GEOL SURVEY,MS 954,RESTON,VA 22092, USA. NR 41 TC 31 Z9 34 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 20 PY 1995 VL 123 IS 1-4 BP 89 EP 105 DI 10.1016/0009-2541(95)00040-S PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RL564 UT WOS:A1995RL56400006 ER PT J AU CALVO, JP JONES, BF BUSTILLO, M FORT, R ALONSOZARZA, AM KENDALL, C AF CALVO, JP JONES, BF BUSTILLO, M FORT, R ALONSOZARZA, AM KENDALL, C TI SEDIMENTOLOGY AND GEOCHEMISTRY OF CARBONATES FROM LACUSTRINE SEQUENCES IN THE MADRID BASIN, CENTRAL SPAIN SO CHEMICAL GEOLOGY LA English DT Article ID STABLE ISOTOPES; FACIES ANALYSIS; DOLOMITE; DIAGENESIS; HOLOCENE; MIOCENE; CLASSIFICATION; RECOGNITION; MINERALOGY; GENESIS AB Lacustrine and alluvial carbonate facies have been investigated in Middle Miocene successions of the western side of the Madrid Basin in order to evaluate paleoenvironments in which carbonates formed. Carbonate facies are varied and include: (1) calcrete and dolocrete; (2) pond deposits; (3) lake margin dolostone; (4) mudflat carbonate; and (5) open-lake carbonate facies. The dominant mineralogy of these is dolomite and/or low-Mg calcite. No high-Mg calcite or aragonite have been detected in any sample. delta(18)O- and delta(18)C-values range from -8.20 to -1.80 parts per thousand PDB and -10.25 to -0.70 parts per thousand PBD, respectively. More negative delta(18)O- and delta(13)C-values correspond to predominantly calcite calcretes and to carbonate deposited in ponds at the foot of arkosic alluvium. Higher delta(18)O-values are from both lacustrine carbonate and dolocrete. This latter lithofacies has strong geochemical similarities to dolostones deposited in a lake margin environment. Mudflat carbonate, deposited on shallow platforms subject to lake water oscillation, shows great heterogeneity in both stable isotope value and trace-element content. The mineralogy of these carbonates is dominated by calcite and the limestones contain molds of gypsum. Occurrence of calcitized dolomite textures in these facies suggests the influence of fresher water during expanding lacustrine cycles or further interaction with less saline groundwater. Trace-element contents are considered to be potential indicators of the different carbonate facies types, thus aiding the paleoenvironmental interpretation. However, discrimination among carbonate facies on the basis of trace-element contents appears to be dependent on the statistical method utilized for treatment of data. More information is needed to ascertain their use as paleoenvironmental indicators. C1 US GEOL SURVEY, RESTON, VA 22092 USA. CSIC, INST GEOL ECON, E-28040 MADRID, SPAIN. RP CALVO, JP (reprint author), UNIV COMPLUTENSE MADRID, DEPT PETROL & GEOQUIM, E-28040 MADRID, SPAIN. RI Fort, R/H-3472-2011 OI Fort, R/0000-0001-9967-2824 NR 65 TC 45 Z9 45 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 20 PY 1995 VL 123 IS 1-4 BP 173 EP 191 DI 10.1016/0009-2541(94)00161-Z PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RL564 UT WOS:A1995RL56400010 ER PT J AU JACKSON, LL BAEDECKER, PA FRIES, TL LAMOTHE, PJ AF JACKSON, LL BAEDECKER, PA FRIES, TL LAMOTHE, PJ TI GEOLOGICAL AND INORGANIC MATERIALS SO ANALYTICAL CHEMISTRY LA English DT Review ID NEUTRON-ACTIVATION-ANALYSIS; PLASMA-MASS-SPECTROMETRY; ATOMIC-ABSORPTION SPECTROMETRY; X-RAY-FLUORESCENCE; RARE-EARTH ELEMENTS; ROCK REFERENCE SAMPLES; ION-INTERACTION CHROMATOGRAPHY; ANODIC-STRIPPING VOLTAMMETRY; ELECTRON-MICROPROBE ANALYSIS; LASER RAMAN MICROPROBE C1 US GEOL SURVEY,GEOCHEM BRANCH,MENLO PK,CA 94025. US GEOL SURVEY,NATL CTR,GEOCHEM BRANCH,RESTON,VA 22092. RP JACKSON, LL (reprint author), US GEOL SURVEY,GEOCHEM BRANCH,BOX 25046,DFC,MS 973,DENVER,CO 80225, USA. NR 301 TC 4 Z9 5 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 15 PY 1995 VL 67 IS 12 BP R71 EP R85 PG 15 WC Chemistry, Analytical SC Chemistry GA RD319 UT WOS:A1995RD31900005 ER PT J AU SHOEMAKER, EM AF SHOEMAKER, EM TI COMET SHOEMAKER-LEVY-9 AT JUPITER SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article C1 LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP SHOEMAKER, EM (reprint author), US GEOL SURVEY,ASTROGEOL BRANCH,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 0 TC 8 Z9 8 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1995 VL 22 IS 12 BP 1555 EP 1556 DI 10.1029/95GL01529 PG 2 WC Geosciences, Multidisciplinary SC Geology GA RE528 UT WOS:A1995RE52800024 ER PT J AU CHRISTENSEN, NI MOONEY, WD AF CHRISTENSEN, NI MOONEY, WD TI SEISMIC VELOCITY STRUCTURE AND COMPOSITION OF THE CONTINENTAL-CRUST - A GLOBAL VIEW SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COMPRESSIONAL WAVE VELOCITIES; UPPER-MANTLE; EVOLUTION; ROCKS; REFLECTIVITY; CONSTITUTION; ANISOTROPY; SEISMOLOGY; THICKNESS; PRESSURES AB Seismic techniques provide the highest-resolution measurements of the structure of the crust and have been conducted on a worldwide basis. We summarize the structure of the continental crust based on the results of seismic refraction profiles and infer crustal composition as a function of depth by comparing these results with high-pressure laboratory measurements of seismic velocity for a wide range of rocks that are commonly found in the crust, The thickness and velocity structure of the crust are well correlated with tectonic province, with extended crust showing an average thickness of 30.5 lan and orogens an average of 46.3 km. Shields and platforms have an average crustal thickness nearly equal to the global average. We have corrected for the nonuniform geographical distribution of seismic refraction profiles by estimating the global area of each major crustal type. The weighted average crustal thickness based on these values is 41.1 km. This value is 10% to 20% greater than previous estimates which underrepresented shields, platforms, and orogens. The average compressional wave velocity of the crust is 6.45 km/s, and the average velocity of the uppermost mantle (Pn velocity) is 8.09 km/s. We summarize the velocity structure of the crust at 5-km depth intervals, both in the form. of histograms and as an average velocity-depth curve, and compare these determinations with new measurements of compressional wave velocities and densities of over 3000 igneous and metamorphic rock cores made to confining pressures of 1 GPa. On the basis of petrographic studies and chemical analyses, the rocks have been classified into 29 groups. Average velocities, densities, and standard deviations are presented for each group at 5-km depth intervals to crustal depths of 50 km along three different geotherms. This allows us to develop a model for the composition of the continental crust. Velocities in the upper continental crust are matched by velocities of a large number of lithologies, including many low-grade metamorphic rocks and relatively silicic gneisses of amphibolite facies grade. In midcrustal regions, velocity gradients appear to originate from an increase in metamorphic grade, as well as a decrease in silica content. Tonalitic gneiss, granitic gneiss, and amphibolite are abundant midcrustal lithologies. Anisotropy due to preferred mineral orientation is likely tb be significant in upper and midcrustal regions. The bulk of the lower continental crust is chemically equivalent to gabbro, with velocities in agreement with laboratory measurements of mafic granulite. Garnet becomes increasingly abundant with depth, and mafic garnet granulite is the dominant rock type immediately above the Mohorovicic discontinuity. Average compressional wave velocities of common crustal rock types show excellent correlations with density. The mean crustal density calculated from our model is 2830 kg/m(3), and the average SiO2 content is 61.8%. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP CHRISTENSEN, NI (reprint author), PURDUE UNIV, DEPT EARTH & ATMOSPHER SCI, W LAFAYETTE, IN 47907 USA. NR 81 TC 1469 Z9 1549 U1 10 U2 143 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 9761 EP 9788 DI 10.1029/95JB00259 PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600001 ER PT J AU DODGE, DA BEROZA, GC ELLSWORTH, WL AF DODGE, DA BEROZA, GC ELLSWORTH, WL TI FORESHOCK SEQUENCE OF THE 1992 LANDERS, CALIFORNIA, EARTHQUAKE AND ITS IMPLICATIONS FOR EARTHQUAKE NUCLEATION SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID STRESS DROP; MECHANICS; FAULTS; LOCATIONS; SLIP AB The June 28, 1992, Landers, California, earthquake (M(w)=7.3) was preceded for about 7 hours by a foreshock sequence consisting of at least 28 events. In this study we examine the geometry and temporal development of the foreshocks using high-precision locations based on cross correlation of waveforms recorded at nearby stations. By aligning waveforms, rather than frying to obtain travel time picks for each event independently, we are able to improve the timing accuracy greatly and to make very accurate travel time picks even for emergent arrivals. We perform a joint relocation using the improved travel times and reduce the relative location errors to less than 100 m horizontally and less than 200 m vertically. With the improved locations the geometry of the foreshock sequence becomes clear. The Landers foreshocks occurred at a right step of about 500 m in the mainshock fault plane. The nucleation zone as defined by the foreshock sequence is southeast trending to the south and nearly north trending to the north of the right step. This geometry is confirmed by the focal mechanisms of the foreshock sequence, which are right-lateral and follow the trend as determined by the foreshock locations on the two straight segments of the fault, and are rotated clockwise for foreshocks that occur within the step. The extent of the foreshock sequence is approximately 1 km both vertically and horizontally. Modeling of the Coulomb stress changes due to all previous foreshocks indicates that the foreshocks probably did not trigger each other. This result is particularly clear for the M(w)=4.4 immediate foreshock. Since Stress transfer in the sequence appears not to have played a significant role in its development, we infer an underlying aseismic nucleation process, probably aseismic creep. Other studies have shown that earthquake nucleation may be controlled by fault zone irregularities. This appears to be true in the case of the Landers earthquake, although the size of the irregularity is so small that it is not detectable by standard location techniques. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP DODGE, DA (reprint author), STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. NR 38 TC 112 Z9 117 U1 2 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 9865 EP 9880 DI 10.1029/95JB00871 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600007 ER PT J AU JOHN, BE HOWARD, KA AF JOHN, BE HOWARD, KA TI RAPID EXTENSION RECORDED BY COOLING-AGE PATTERNS AND BRITTLE DEFORMATION, NAXOS, GREECE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID METAMORPHIC CORE COMPLEXES; WOMAN MOUNTAINS AREA; WEST CENTRAL ARIZONA; PAPUA-NEW-GUINEA; AEGEAN SEA; DENTRECASTEAUX ISLANDS; DUCTILE EXTENSION; CYCLADES ISLANDS; EVOLUTION; BELT AB The metamorphic core complex exposed as the island of Naxos in the Aegean Sea records an unusually complete sequence of structures developed as a result of continental extension. The structures formed during Miocene rise and cooling from ductile, upper amphibolite facies and anatectic conditions to brittle neat-surface conditions beneath the Naxos detachment fault. Top-to-the-north ductile fabrics in the footwall, which initially developed during amphibolite facies prograde metamorphism, were overprinted by a succession of north directed, normal sense lower-temperature brittle structures as the footwall was tectonically unloaded and unroofed. Pseudotachylite and cataclasite formation, brittle faulting, alteration, and erosion of the footwall occurred during continued slip and tectonic denudation. Neogene conglomerate and megabreccia, in part derived from exhumation of this footwall, lie structurally above the peripheral Naxos fault. Published K-Ar and Ar-40/Ar-39 ages for hornblende, white mica, and biotite in the footwall decrease northwestward; apparent ages 17-50 Ma in the southeast correspond to areas of low metamorphic grade where preextension argon was partially retained. Published ages 16-10 Ma in higher-grade rocks of the domal core in the north are cooling ages that for each of the three minerals show a component of younging in the NNE direction of extension. Assuming this is the direction of unroofing, we interpret the rate of this younging as the fault slip rate as the footwall rocks moved >20 km SSW relative to their hanging wall along the base of the Naxos detachment fault. The calculated rates of slip average 5-8 mm/yr, comparable to maximum rates reported in the Basin and Range province. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP JOHN, BE (reprint author), UNIV WYOMING, DEPT GEOL & GEOPHYS, LARAMIE, WY 82071 USA. NR 62 TC 53 Z9 53 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 9969 EP 9979 DI 10.1029/95JB00665 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600013 ER PT J AU PRIBNOW, DFC SASS, JH AF PRIBNOW, DFC SASS, JH TI DETERMINATION OF THERMAL-CONDUCTIVITY FOR DEEP BOREHOLES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SCIENTIFIC-DRILLING-PROJECT; HEAT-FLOW; CAJON PASS; WELL LOGS; ROCKS; FRAGMENTS; PRESSURE; BASALT AB Two methods for thermal conductivity determinations on rock cores and fragments were tested on a suite of samples from the Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland (KTB) superdeep drill hole in Germany. They were also compared with estimates of thermal conductivity using the mineral composition of the rock and physical well logs and with in situ thermal conductivity measurements. Laboratory methods provide reasonably precise determinations of the thermal conductivities of both solid core (+/-5%) and drill cuttings (+/-10%) at room temperature and pressure. The most common methods presently used for crystalline rocks are the steady state ''divided-bar'' (DB) technique and the transient ''half-space'' line source (LS). Sample preparation and measurement times are comparable for the DB and LS, with sample preparation being more time consuming on average. For isotropic rocks there is little to choose from between the two methods, which both give reliable values of conductivity in the vertical direction. The LS is easier to set up and use in field laboratory situations, which renders it the preferred method for field reconnaissance. The gneissic crystalline rocks penetrated by the KTB boreholes typically have anisotropy of the order of 10-20%. The DB provides unambiguous values of conductivity in a given direction, so its use is preferable for obtaining both principal conductivities and the vertical component. Anisotropy can be estimated using LS measurements in many different directions, but the potential for large random errors is much greater than with the more straightforward DB approach. For deep research wells the difficulties of extrapolating laboratory results to in situ conditions (particularly temperature) present additional obstacles to determining heat flow. Laboratory measurements of water-saturated samples under in situ conditions, combined with in situ measurements and judicious use of calculations based on mineralogy and well log derived physical properties, can aid in the accurate characterization of thermal conductivity in deep wells. The application of different methods helped to link variations of heat flow with depth in the KTB hole to the anisotropy of thermal conductivity or thermal refraction and thus allowed the calculation of background heat flux in this geologically complex area. C1 US GEOL SURVEY, GEOTHERMAL STUDIES PROJECT, FLAGSTAFF, AZ 86001 USA. NR 63 TC 37 Z9 38 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 9981 EP 9994 DI 10.1029/95JB00960 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600014 ER PT J AU MATHEZ, EA DUBA, AG PEACH, CL LEGER, A SHANKLAND, TJ PLAFKER, G AF MATHEZ, EA DUBA, AG PEACH, CL LEGER, A SHANKLAND, TJ PLAFKER, G TI ELECTRICAL-CONDUCTIVITY AND CARBON IN METAMORPHIC ROCKS OF THE YUKON-TANANA TERRANE, ALASKA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GRAIN-BOUNDARY GRAPHITE; DENALI FAULT SYSTEM; CONTINENTAL-CRUST; REFLECTION; WATER; TEMPERATURES; BASALTS; MANTLE; MODELS; MATTER AB Electrical conductivity of a water-saturated quartz-mica-garnet-schist, collected from a surface outcrop near the Denali Fault Zone in the Yukon-Tanana terrane of east central Alaska, increases slightly with pressure to about 200 MPa, This behavior is unlike that exhibited by other Yukon-Tanana samples or by most rocks from other locations, Detailed petrographic examination of the sample revealed the presence of a stringer of carbonaceous material generally less than 10 mu m thick enclosed in and intergrown with one of the muscovite layers and extending for about 2 cm along the foliation, The stringer is probably responsible for the anomalous conductivity change with pressure, making the sample the first for which anomalous electrical conductivity behavior can be attributed to carbon associated with a specific feature, The carbonaceous stringer together with its host muscovite layer are deformed and broken around a rotated garnet porphyroclast, The deformation was accommodated by plastic deformation of quartz and therefore occurred in the ductile regime under conditions at least equivalent to greenschist facies metamorphism, We interpret the textural relations to indicate that the carbonaceous material was formed by fluid deposition in a fracture formed within the muscovite layer, possibly during the main phase of metamorphism and deformation, and that the mica and carbon stringer were then deformed by the noncoaxial deformation responsible for rotation of the garnet porphyroclasts. Together the facts that the deformation resulting in garnet rotation was ductile and that the garnet rotation disrupted the stringer demonstrate that the carbonaceous stringer was present at depth (i,e,, > 10 km). Brittle deformation on the microscopic scale is observed to have broken the connectivity of the carbon stringer, explaining in part why the rock does not exhibit anomalously high conductivity at 0.1 MPa (1 atm) pressure, The brittle deformation is interpreted to have been caused by unloading due to uplift. The observations indicate that carbonaceous material may exert a primary control on crustal electrical conductivity because it may be present as interconnected arrays in grain boundaries or microfractures or in megascopic, throughgoing fractures. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, LOS ALAMOS, NM 87545 USA. LAWRENCE LIVERMORE NATL LAB, DEPT EARTH SCI, LIVERMORE, CA 94550 USA. RP MATHEZ, EA (reprint author), AMER MUSEUM NAT HIST, DEPT EARTH & PLANETARY SCI, CENT PK W & 79TH ST, NEW YORK, NY 10024 USA. NR 42 TC 29 Z9 29 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10187 EP 10196 DI 10.1029/95JB00615 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600027 ER PT J AU SPENCER, JE RICHARD, SM REYNOLDS, SJ MILLER, RJ SHAFIQULLAH, M GILBERT, WG GRUBENSKY, MJ AF SPENCER, JE RICHARD, SM REYNOLDS, SJ MILLER, RJ SHAFIQULLAH, M GILBERT, WG GRUBENSKY, MJ TI SPATIAL AND TEMPORAL RELATIONSHIPS BETWEEN MIDTERTIARY MAGMATISM AND EXTENSION IN SOUTHWESTERN ARIZONA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID WEST-CENTRAL ARIZONA; METAMORPHIC CORE COMPLEXES; PLATE-TECTONIC EVOLUTION; UNITED-STATES; SOUTHEASTERN CALIFORNIA; GREAT-BASIN; CENOZOIC VOLCANISM; MOUNTAINS; COLORADO; HISTORY AB Cenozoic magmatism in southwestern Arizona, which is within the Basin and Range tectonic province, occurred almost entirely between 15 and 25 Ma. Volcanic rocks typically consist, in ascending order, of (1) a thin sequence of mafic to intermediate lava flows, (2) voluminous felsic lava flows and pyroclastic rocks with minor to moderate amounts of intermediate to mafic lava flows, and (3) basalt and andesite. Volcanic rock sequences rest disconformably on pre-Tertiary bedrock in most areas but locally overlie substantial coarse elastic debris that was deposited immediately before and during earliest magmatism. Prevolcanic elastic debris is interpreted as a consequence of local early normal faulting. In most regions, tilting related to extension began later and occurred during or after eruption of felsic volcanic rocks and before the end of younger mafic volcanism. Extension generally ended before about 17 Ma except in a northwest trending belt adjacent to the relatively unfaulted and topographically elevated Transition Zone tectonic province which is adjacent to the Colorado Plateau. Rapid cooling of metamorphic core complexes and tilting of young basalts and coarse elastic rocks continued in this belt until as recently as 11 Ma. Extension was extreme in this belt, whereas it was generally moderate to slight in other parts of southwestern Arizona. Large-magnitude extension was not associated with areas of greatest igneous activity, and rapid cooling and exhumation of core complexes postdated local magmatism. These relationships are inconsistent with theories that relate genesis of metamorphic core complexes to magma intrusion in the upper crust. Except for young extension in this northwest trending belt, there are no apparent regional migration trends for either magmatism or extension within southwestern Arizona. Lack of substantial extension before magmatism and general lack of magmatism during youngest extension are inconsistent with the hypothesis that magmatism was the product of decompression melting during lithospheric extension. The long duration and large magnitude of extension adjacent to the Transition Zone tectonic province and within an area of earlier crustal thickening are consistent with the hypothesis that extension was driven by the gravitational potential energy of elevated land mass and crustal roots. Regional magmatic heating apparently weakened the lithosphere and triggered extension but did not control extension locally. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. UNIV ARIZONA, DEPT GEOSCI, TUCSON, AZ 85721 USA. RP SPENCER, JE (reprint author), ARIZONA GEOL SURVEY, 845 N PK AVE, TUCSON, AZ 85719 USA. NR 156 TC 51 Z9 51 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10321 EP 10351 DI 10.1029/94JB02817 PG 31 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600037 ER PT J AU SCOTT, RB UNRUH, DM SNEE, LW HARDING, AE NEALEY, LD BLANK, HR BUDAHN, JR MEHNERT, HH AF SCOTT, RB UNRUH, DM SNEE, LW HARDING, AE NEALEY, LD BLANK, HR BUDAHN, JR MEHNERT, HH TI RELATION OF PERALKALINE MAGMATISM TO HETEROGENEOUS EXTENSION DURING THE MIDDLE MIOCENE, SOUTHEASTERN NEVADA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID WESTERN UNITED-STATES; RANGE PROVINCE; VOLCANIC-ROCKS; GREAT-BASIN; TERTIARY EXTENSION; ISOTOPIC EVIDENCE; EASTERN NEVADA; NORMAL FAULTS; UTAH; EVOLUTION AB Volcanism migrated southward in the northern Basin and Range province in the Oligocene and early Miocene to produce voluminous calcalkaline silicic ash flow tuffs. Alkaline volcanism became dominant by middle Miocene (17-14 Ma) as smaller volumes of rhyolite-trachyte-basalt suites were erupted from the relatively small Kane Springs Wash caldera complex including the Narrow Canyon, Boulder Canyon, and Kane Springs Wash calderas in southeastern Nevada. Only minor extension affected the Kane Wash area before the end of calcalkaline activity, but extension expressed by rate of progressive stratal tilt peaked (15-13.5 Ma) with peralkaline magmatism (14.7-14.4 Ma). Variations in distribution, degree, style, and timing of deformation demonstrate heterogeneous extension in the Kane Wash area. Only minor extension and tilting persisted post-middle Miocene (<12 Ma). All major eruptive sources overlap domains of rapid extension. Most of the eruptive volumes from the two oldest calderas of the complex apparently pooled within their calderas, creating outflow deficits. Denudation faulting associated with magmatic tumescence may have followed preexisting active extensional fault systems to unload magma chambers, thus triggering eruptions into structural depressions. Evolution of alkaline magmas is demonstrated by progressive increases in peralkalinity and high field strength elements such as Zr, Y, and Nb. Nd, Pb, and Sr isotopic compositions provide evidence that significantly less crustal interaction affected middle Miocene peralkaline magmas than pre-middle Miocene calcalkaline magmas. epsilon(Nd) values are -5 to -7 for peralkaline magmas and -7 to -11 for calcalkaline magmas; Pb-208/(204)Pb ratios are 38.2-38.6 for peralkaline magmas and 38.5-38.9 for calcalkaline magmas. Regional cooling, short duration of magmatism, small volumes of magma, and local extension caused less crustal interaction in peralkaline Kane Wash magmas than in earlier magmas. North of the Kane Wash area, older more voluminous calcalkaline magmas intruded hotter crust for a longer period and thus interacted with the crust to a greater degree in spite of synvolcanic extension. RP SCOTT, RB (reprint author), US GEOL SURVEY, DENVER FED CTR, BOX 25046, MS 913, DENVER, CO 80225 USA. RI Rohlf, F/A-8710-2008 NR 83 TC 17 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10381 EP 10401 DI 10.1029/94JB03217 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600039 ER PT J AU BROOKS, WE THORMAN, CH SNEE, LW AF BROOKS, WE THORMAN, CH SNEE, LW TI THE AR-40/AR-39 AGES AND TECTONIC SETTING OF THE MIDDLE EOCENE NORTHEAST NEVADA VOLCANIC FIELD SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID WESTERN-UNITED-STATES; IGNEOUS ROCKS; EVOLUTION; UTAH; MINERALIZATION; SYSTEMATICS; BASIN AB Widespread middle to late Eocene calc-alkalic volcanism, which formed the Northeast Nevada Volcanic Field, marks the earliest Tertiary volcanism in the northern Basin and Range. The central part of this major field in northeast Nevada and adjacent Utah is herein defined by 23 Ar-40/Ar-39 ages that range from 42.6 to 39.0 Ma, rock chemistry from 12 localities, stratigraphic position of the volcanic rocks above a regional middle Eocene unconformity, volcanic setting, and lithology. The type area is at Nanny Creek, in the northern Pequop Mountains, Nevada, where rhyolite ash flow tuffs are overlain by a thick section of intercalated andesitic to dacitic flows and flow breccias and rhyolite ash flow tuffs. The intermediate composition rocks are locally derived throughout the volcanic field, whereas the sources for rhyolite ash flow tuffs are unknown. The uniform and widespread occurrence of the andesitic and dacitic flows and flow breccias strongly suggests that the upper crust was perforated by intermediate composition magma across the entire region. In the central part of the field the middle Eocene volcanic rocks rest with depositional angular discordance on deformed middle Paleozoic to Triassic strata; ostracode-bearing limestone, probably of early Eocene age, is locally present below the volcanic rocks. In the western and southeastern parts of the field these middle Eocene volcanic rocks rest with depositional angular discordance on lower Eocene lacustrine strata of the Elko and White Sage Formations, respectively. This angular discordance documents a middle Eocene deformational event previously unrecognized in the region. RP BROOKS, WE (reprint author), US GEOL SURVEY, BOX 25046, MS 905, DENVER, CO 80225 USA. NR 58 TC 44 Z9 44 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10403 EP 10416 DI 10.1029/94JB03389 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600040 ER PT J AU WENRICH, KJ BILLINGSLEY, GH BLACKERBY, BA AF WENRICH, KJ BILLINGSLEY, GH BLACKERBY, BA TI SPATIAL MIGRATION AND COMPOSITIONAL CHANGES OF MIOCENE-QUATERNARY MAGMATISM IN THE WESTERN GRAND-CANYON SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID SOUTHWESTERN UNITED-STATES; COLORADO-PLATEAU; CHEMICAL CLASSIFICATION; VOLCANIC-ROCKS; MANTLE; EVOLUTION; ARIZONA; BASIN; TIME; RANGE AB Lithospheric extension appears to be responsible for erosional and tectonic evolution of the western margin of the Colorado Plateau. Late Cenozoic (20 Ma to 10,000 years) basaltic flows, scoria cones, necks, dikes, and sills exposed in the Western Grand Canyon region offer a unique opportunity to place age constraints on the landscape evolution. New K-Ar ages show that these basaltic rocks become progressively younger to the northeast from the Hualapai and Shivwits Plateaus onto the Uinkaret Plateau, a distance of about 100 km. Magmatism appears to have migrated at a rate of about 0.45 cm/yr until sometime between 13,5 and 9.2 Ma, when the rate changed to about 1.15 cm/yr. Recent regional geologic mapping indicates that extensional faulting, with ubiquitous downdrop to the west, accompanied this magmatism; the Hurricane Fault offsets lavas as young as 0.29 Ma. Young fault scarps in sedimentary rocks, and historic seismic activity along these faults, indicate that the region is still undergoing faulting. The basalts form three relatively distinct groups based on their age, chemistry, and geographic distribution: (1) 20-11 Ma, (2) 11-4.5 Ma, and (3) less than or equal to 4.5 Ma. The older basalts (>11 Ma) are petrographically and compositionally distinct from younger basalts; their olivine and augite are more Mg rich with lower TiO2 and higher Ni, Cr, and incompatible element contents. Group 1 basalts have more radiogenic Sr and less radiogenic Nd isotopic compositions than younger group 2 and 3 basalts. Overall, present-day Sr isotopic compositions range from 0.70344 to 0.70505, Nd-143/Nd-144 from 0.51291 to 0.51227 (epsilon(Nd) = +5.4 to -7.1), and Pb-206/Pb-204 from 17.951 to 19.091. Group 1 basalts were probably derived from asthenospheric mantle melts that underwent crustal contamination. These basalts appear to have been generated originally from more primitive melts than groups 2 and 3, which were probably also derived from asthenospheric mantle-derived magmas but underwent only minor crustal contaminations. Group 2 basalts appear to be transitional between groups 1 and 3. The intervals 13-9 Ma and 4.6-4.3 Ma temporally separate the three chemically distinct groups of basalts in the Western Grand Canyon. These periods correspond closely with major Miocene and Pliocene plate reorganizations in the western United States at about 12.5-10 Ma and 3.9-3.4 Ma. These changes in plate motion were reflected in changes in the rate of magmatism migration in the Western Grand Canyon. Recent movements on the Hurricane and Toroweap Faults appear directly related to the <4.5 Ma volcanism and are probably a result of recent plate reorganization. C1 US GEOL SURVEY, 2255 N GEMINI DR, FLAGSTAFF, AZ 86001 USA. CALIF STATE UNIV FRESNO, DEPT GEOL, FRESNO, CA 93740 USA. RP WENRICH, KJ (reprint author), US GEOL SURVEY, MS 939, DENVER, CO 80225 USA. NR 66 TC 41 Z9 47 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10417 EP 10440 DI 10.1029/95JB00373 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600041 ER PT J AU FALKNER, CM MILLER, CF WOODEN, JL HEIZLER, MT AF FALKNER, CM MILLER, CF WOODEN, JL HEIZLER, MT TI PETROGENESIS AND TECTONIC SIGNIFICANCE OF THE CALC-ALKALINE, BIMODAL AZTEC WASH PLUTON, ELDORADO MOUNTAINS, COLORADO RIVER EXTENSIONAL CORRIDOR SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID PEACH SPRINGS TUFF; EASTERN MOJAVE DESERT; SOUTHERN NEVADA; EXPERIMENTAL CALIBRATION; NORTHWESTERN ARIZONA; ISOTOPIC EVIDENCE; VOLCANIC-ROCKS; UNITED-STATES; TRACE-ELEMENT; CALIFORNIA AB The 15.7 Ma Aztec Wash pluton is located in the central Eldorado Mountains of the Colorado River extensional corridor in southern Nevada, immediately south of the well-known imbricated volcanic sequence that has been widely cited in studies of extensional tectonism (e.g., Anderson, 1971). It is a shallow level (less than or equal to 5 km), essentially bimodal complex, primarily made up of granite (similar to 72 wt % SiO2) and diabase and diorite (similar to 54 wt % SiO2), with minor amounts of more mafic, intermediate, and highly evolved rocks. The mafic and felsic magmas mingled extensively but mixed only to a limited extent. Late synplutonic mafic and felsic dikes represent continuing injection of the same bimodal magmas. The mafic rocks have high incompatible element concentrations (e.g., K2O similar to 3 wt %, Ba similar to 1600 ppm, light rare earth elements 350 x chondrite) and enriched isotopic compositions (epsilon(Nd)-7.5, Sr-87/Sr-86 0.708); generation in ancient, enriched mantle lithosphere with limited subsequent crustal contamination is inferred, The granite is more potassic (similar to 5 wt %) than the mafic rocks, but it has comparable or lower concentrations of most incompatible elements; its isotopic composition (epsilon(Nd)-10, Sr-87/Sr-86 0.710) is intermediate between those of the mafic rocks and local ancient crust. The granites thus indicate hybridization of the crust by mafic magma, but it is unclear whether this hybridization occurred at deeper levels in this magmatic system, or during an earlier mid-Tertiary or Mesozoic magmatic event. Emplacement of the Aztec Wash pluton preceded peak east west extension in the northern Eldorado Mountains (similar to 15.2 Ma (Gans et al., 1994)), but it coincided with at least modest extension as indicated by the uniform NS orientation of the late dikes and the mafic injections into the magma chamber. Total extension and tilting of the pluton after crystallization was minor, in contrast to the east tilted area to the north and west tilted area to the south. Timing and style of extension are thus consistent with the pluton's location within, and perhaps mechanical influence on, a major accommodation zone, as suggested by Faulds et al. (1990) and Faulds (1994). C1 NEW MEXICO INST MIN & TECHNOL, NEW MEXICO GEOCHRONOL RES LAB, SOCORRO, NM 87801 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP FALKNER, CM (reprint author), VANDERBILT UNIV, DEPT GEOL, NASHVILLE, TN 37235 USA. NR 70 TC 25 Z9 25 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10453 EP 10476 DI 10.1029/94JB03357 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600043 ER PT J AU MINOR, SA AF MINOR, SA TI SUPERPOSED LOCAL AND REGIONAL PALEOSTRESSES - FAULT-SLIP ANALYSIS OF NEOGENE EXTENSIONAL FAULTING NEAR COEVAL CALDERA COMPLEXES, YUCCA FLAT, NEVADA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article; Proceedings Paper CT Symposium on Cenozoic Magmatism in the Colorado River Extensional Corridor and Adjacent Areas, at the Geological-Society-of-America Cordilleran/Rocky-Mountain-Section Meeting CY 1993 CL RENO, NV SP GEOL SOC AMER, CORDILLERAN ROCKY MT SECT ID GRAVITY-INDUCED STRESSES; WESTERN UNITED-STATES; GREAT-BASIN; RANGE PROVINCE; FIELD; INVERSION; MAGMATISM; EVOLUTION; PATTERNS; ARIZONA AB Numerous reduced stress tensors are computed by multiple inversions of 906 temporally and spatially partitioned fault-slip data from the Yucca Flat region in the southwest Nevada volcanic field to constrain the Neogene paleostress and faulting history and to investigate how the regional tectonic stress field was affected by local caldera magmatism. Perturbed, shallow (<400 m), pre-11 Ma paleostress configurations, determined west and northwest of present (post-11 Ma) Yucca Flat basin, existed during mild extensional faulting and are attributed to superposition of transient caldera-magmatic stresses on the regional stress field. Northwest of Yucca Flat a progressive shift in least principal stress (sigma(3)) directions near known calderas located 5-15 km to the west occurred under a normal-slip stress state during caldera development between about 15 and 13 Ma. A brief (similar to 0.5 m.y.) change to a strike-dip stress state occurred at about 13 Ma and was accompanied by small-offset, quasiconjugate strike-slip faulting. This stress state was most distinct, relative to a normal-slip state, near calderas where stress solutions and fault relations indicate closer affinities to a reverse-slip state. Inferred 11.6-11.45 Ma paleostress tensors indicate radial tension associated with either initial caldera collapse or local post-collapse topographic modification of the stress field. Post-11 Ma normal-slip stress tensors are associated with normal- and oblique-slip faults that accommodated subsidence and eastward extension of Yucca Flat basin away from the caldera complexes. These tensors do not indicate stress modifications due to residual caldera-related effects and thus were used to infer post-11 Ma regional stress changes. The stress field has rotated as much as 65 degrees clockwise since 11 Ma during extensional development of Yucca Flat basin, with most of the rotation and extension occurring before about 8.5 Ma. Results suggest that shallow magmatism and caldera development can strongly alter extensional tectonic stress fields, fault patterns, and slip directions in the uppermost crust out to distances of roughly two magma chamber radii away from a magma body. RP MINOR, SA (reprint author), US GEOL SURVEY, POB 25046, MS 913, DENVER, CO 80225 USA. NR 52 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1995 VL 100 IS B6 BP 10507 EP 10528 DI 10.1029/95JB00078 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC486 UT WOS:A1995RC48600046 ER PT J AU HODGES, CA AF HODGES, CA TI MINERAL-RESOURCES, ENVIRONMENTAL-ISSUES, AND LAND-USE SO SCIENCE LA English DT Article ID SUSTAINABLE DEVELOPMENT; NATURAL-RESOURCES; SCARCITY AB Contrary to predictions from the 1950s through the mid-1980s, persistent shortages of nonfuel minerals have not occurred, despite prodigious consumption, and world reserves have increased. Global availability of raw materials is relevant to policy decisions regarding mineral development and land use. Justification for environmental protection may exceed that for mining a specific ore body. Demand for environmental accountability is rising worldwide, and new technologies are enabling internalization of costs. Mineral-rich developing nations plagued by inefficient state-owned mining enterprises, high population growth rates, and environmental degradation could realize substantial benefit by reforming government policies to encourage foreign investment in resources and by appropriate allocation of mineral rents. RP HODGES, CA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 85 TC 34 Z9 35 U1 3 U2 17 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 2 PY 1995 VL 268 IS 5215 BP 1305 EP 1312 DI 10.1126/science.268.5215.1305 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RB198 UT WOS:A1995RB19800027 PM 17778975 ER PT J AU NEUZIL, CE AF NEUZIL, CE TI ABNORMAL PRESSURES AS HYDRODYNAMIC PHENOMENA SO AMERICAN JOURNAL OF SCIENCE LA English DT Article ID FLUID PRESSURES; GROUNDWATER-FLOW; PORE PRESSURE; POROSITY REDUCTION; TOPOGRAPHIC RELIEF; SEDIMENTARY BASIN; EROSIONAL CHANGES; STRAIN RATES; GULF-COAST; ROCKS AB So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually palys an important role. In this paper I develop the theoretical frBmework for aabnormal pressures as hydrodynamic phenomena, showX that it explains the manifold occurrences of abnormal pressures, and examine the implications of this approach. Abnormal pressures can be explained as occurring in flow regimes that are both equilibrated and disequilibrated hydrodynamically. The former are ''adjusted'' to their geologic and hydrologic surroundings while the latter are not. Equilibrium-type abnormal pressures generally result from topographically-driven flow (as in artesian basins) but may also occur as a result of osmosis or fluid density contrasts. The more common and varied disequilibrium-type abnormal pressures are caused by natural geologic processes such as compaction, diagenesis, and deformation. These processes have the effect of distributed fluid sources or sinks and are manifested either as actual fluid sources/sinks or as virtual ones involving changing porosity and/or temperature. Disequilibrium-type abnormal pressures can be characterized in terms of three quantities: the size and permeability of their domains and the vigor of the ''geologic forcing'' or magnitude of the source/sink term. Published estimates reveal aa surprising number of distinct geologic processes that can generate forcing sufficient to maintain abnormal pressures in dynamic systems. This observation is crucial to understanding why abnormal pressures need not indicate regimes that have been static over geologic time. Low-permeability regions play key roles in both equilibrium- and disequilibrium-type abnormal pressures. Extensive low-permeability strata are generally required to generate abnormal pressures in topographically-driven flow regimes, while osmotically-driven flow and hydrodynamic disequilibrium occur only within regions composed of or encompassed by low-permeability media. Analyzing abnormal pressures as hydrodynamic phenomena often allows these low permeabilities to be estimated, something that is otherwise difficult to do. In some instances hydrodynamic analyses also shed light on rates of geologic processes and a region's geologic history. RP US GEOL SURVEY, 431 NATL CTR, RESTON, VA 22092 USA. NR 89 TC 165 Z9 173 U1 1 U2 26 PU AMER JOURNAL SCIENCE PI NEW HAVEN PA YALE UNIV, PO BOX 208109, NEW HAVEN, CT 06520-8109 USA SN 0002-9599 EI 1945-452X J9 AM J SCI JI Am. J. Sci. PD JUN PY 1995 VL 295 IS 6 BP 742 EP 786 PG 45 WC Geosciences, Multidisciplinary SC Geology GA RD491 UT WOS:A1995RD49100003 ER PT J AU LOVELAND, TR MERCHANT, JW BROWN, JF OHLEN, DO REED, BC OLSON, P HUTCHINSON, J AF LOVELAND, TR MERCHANT, JW BROWN, JF OHLEN, DO REED, BC OLSON, P HUTCHINSON, J TI SEASONAL LAND-COVER REGIONS OF THE UNITED-STATES SO ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS LA English DT Article DE GLOBAL CHANGE; LAND COVER; PHENOLOGY; REMOTE SENSING ID AVHRR DATA; GLOBAL VEGETATION; CHOROPLETH MAPS; BIOSPHERE MODEL; SATELLITE DATA; GREAT-PLAINS; CLIMATE; CLASSIFICATION; INDEX; ACCURACY AB Global-change investigations have been hindered by deficiencies in the availability and quality of land-cover data. The U.S. Geological Survey and the University of Nebraska-Lincoln have collaborated on the development of a new approach to land-cover characterization that attempts to address requirements of the global-change research community and others interested in regional patterns of land cover. An experimental 1-kilometer-resolution database of land-cover characteristics for the coterminous U.S. has been prepared to test and evaluate the approach. Using multidate Advanced Very High Resolution Radiometer (AVHRR) satellite data complemented by elevation, climate, ecoregions, and other digital spatial datasets, the authors define 159 seasonal land-cover regions. The regionalization is based on a taxonomy of areas with respect to data on land cover, seasonality or phenology, and relative levels of primary production. The resulting database consists of descriptions of the vegetation, land cover, and seasonal, spectral, and site characteristics for each region. These data are used in the construction of an illustrative 1:7,500,000-scale map of the seasonal land-cover regions as well as of smaller-scale maps portraying general land cover and seasonality. The seasonal land-cover characteristics database can also be tailored to provide a broad range of other landscape parameters useful in national and global-scale environmental modeling and assessment. C1 UNIV NEBRASKA,INST AGR & NAT RESOURCES,CTR ADV LAND MANAGEMENT INFORMAT TECHNOL,LINCOLN,NE 68588. HUGHES STX CORP,EROS DATA CTR,SIOUX FALLS,SD 57198. RP LOVELAND, TR (reprint author), US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD 57198, USA. NR 75 TC 99 Z9 104 U1 1 U2 6 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 238 MAIN STREET, CAMBRIDGE, MA 02142 SN 0004-5608 J9 ANN ASSOC AM GEOGR JI Ann. Assoc. Am. Geogr. PD JUN PY 1995 VL 85 IS 2 BP 339 EP 355 DI 10.1111/j.1467-8306.1995.tb01798.x PG 17 WC Geography SC Geography GA RK691 UT WOS:A1995RK69100007 ER PT J AU DOMACK, EW ISHMAN, SE STEIN, AB MCCLENNEN, CE JULL, AJT AF DOMACK, EW ISHMAN, SE STEIN, AB MCCLENNEN, CE JULL, AJT TI LATE HOLOCENE ADVANCE OF THE MULLER ICE SHELF, ANTARCTIC PENINSULA - SEDIMENTOLOGICAL, GEOCHEMICAL AND PALEONTOLOGICAL EVIDENCE SO ANTARCTIC SCIENCE LA English DT Article DE GLACIAL MARINE SEDIMENTS; FORAMINIFERA; HOLOCENE PALEOENVIRONMENT; LITTLE ICE AGE ID BENTHIC FORAMINIFERAL ASSEMBLAGES; POLAR FRONT REGION; SOUTHERN-OCEAN; SEDIMENTATION; ATLANTIC; ECOLOGY; SEA AB Marine sediment cores were obtained from in front of the Muller Ice Shelf in Lallemand Fjord, Antarctic Peninsula in the austral summer of 1990-91. Sedimentological and geochemical data from these cores document a warm period that preceded the advance of the Muller Ice Shelf into Lallemand Fjord. The advance of the ice shelf is inferred from a reduction in the total organic carbon content and an increase in well-sorted, aeolian, sand in cores proximal to the present calving line. This sedimentological change is paralleled by a change in the foraminiferal assemblages within the cores. Advance of the ice shelf is indicated by a shift from assemblages dominated by calcareous benthic and planktonic forms to those dominated by agglutinated forms. A C-14 chronology for the cores indicates that the advance of the Muller Ice Shelf took place c. 400 years ago, coincident with glacier advances in other high southern latitude sites during the onset of the Little Ice Age. Ice core evidence, however, documents this period as one of warmer temperatures for the Antarctic Peninsula. We suggest that the ice shelf advance was linked to the exclusion of circumpolar deep water from the fjord. This contributed to increased mass balance of the ice shelf system by preventing the rapid undermelt that is today associated with warm circumpolar deep water within the fjord. We also document the recent retreat of the calving line of the Muller Ice Shelf that is apparently in response to a recent (four decade long) warming trend along the western side of the Antarctic Peninsula. C1 US GEOL SURVEY,RESTON,VA 22092. UNIV COLORADO,DEPT GEOL,BOULDER,CO 80309. UNIV COLORADO,INSTAAR,BOULDER,CO 80309. COLGATE UNIV,DEPT GEOL,HAMILTON,NY 13346. UNIV ARIZONA,NSF ARIZONA AMS FACIL,TUCSON,AZ 85721. RP DOMACK, EW (reprint author), HAMILTON COLL,DEPT GEOL,CLINTON,NY 13323, USA. NR 37 TC 59 Z9 60 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0954-1020 J9 ANTARCT SCI JI Antarct. Sci. PD JUN PY 1995 VL 7 IS 2 BP 159 EP 170 PG 12 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA RB632 UT WOS:A1995RB63200006 ER PT J AU LOVLEY, DR PHILLIPS, EJP LONERGAN, DJ WIDMAN, PK AF LOVLEY, DR PHILLIPS, EJP LONERGAN, DJ WIDMAN, PK TI FE(III) AND S-0 REDUCTION BY PELOBACTER-CARBINOLICUS SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; FERRIC IRON REDUCTION; NOV SP-NOV; RIBOSOMAL-RNA; GEN-NOV; DESULFUROMONAS-ACETOXIDANS; ALTEROMONAS-PUTREFACIENS; SHEWANELLA-PUTREFACIENS; DISSIMILATORY REDUCTION; PHYLOGENETIC ANALYSIS AB There is a close phylogenetic relationship between Pelobacter species and members of the genera Desulfuromonas and Geobacter, and yet there has been a perplexing lack of physiological similarities. Pelobacter species have been considered to have a fermentative metabolism. In contrast, Desulfuromonas and Geobacter species have a respiratory metabolism with Fe(III) serving as the common terminal electron acceptor in all species. However, the ability of Pelobacter species to reduce Fe(III) had not been previously evaluated. When a culture of Pelobacter carbinolicus that had grown by fermentation of 2,3-butanediol was inoculated into the same medium supplemented with Fe(III), the Fe(III) was reduced. There was less accumulation of ethanol and more production of acetate in the presence of Fe(III). P. carbinolicus grew with ethanol as the sole electron donor and Fe(III) as the sole electron acceptor. Ethanol was metabolized to acetate. Growth was also possible on Fe(III) with the oxidation of propanol to propionate or 'butanol to butyrate if acetate was provided as a carbon source. P. carbinolicus appears capable of conserving energy to support growth from Fe(III) respiration as it also grew with H-2 or formate as the electron donor and Fe(III) as the electron acceptor. Once adapted to Fe(III) reduction. P. carbinolicus could also grow on ethanol or H-2 with S-0 as the electron acceptor. P. carbinolicus did not contain detectable concentrations of the c-type cytochromes that previous studies have suggested are involved in electron transport to Fe(III) in other organisms that conserve energy to support growth from Fe(III) reduction, These results demonstrate that P. carbinolicus may survive in some sediments as an Fe(III) or S-0 reducer rather than growing fermentatively on rare substrates or syntrophically as an ethanol-oxidizing acetogen. These studies also suggest that the ability to use Fe(III) as a terminal electron acceptor may be an important unifying feature of the Geobacter-Desulfuromonas-Pelobacter branch of the delta Proteobacteria. RP LOVLEY, DR (reprint author), US GEOL SURVEY,430 NATL CTR,RESTON,VA 22092, USA. NR 60 TC 109 Z9 110 U1 1 U2 13 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 1995 VL 61 IS 6 BP 2132 EP 2138 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA RA621 UT WOS:A1995RA62100010 PM 7793935 ER PT J AU PAUL, JH ROSE, JB BROWN, J SHINN, EA MILLER, S FARRAH, SR AF PAUL, JH ROSE, JB BROWN, J SHINN, EA MILLER, S FARRAH, SR TI VIRAL TRACER STUDIES INDICATE CONTAMINATION OF MARINE WATERS BY SEWAGE DISPOSAL PRACTICES IN KEY-LARGO, FLORIDA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID BACTERIA; FLOW AB Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Large limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage Phi HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys. C1 US GEOL SURVEY,CTR COASTAL RES,ST PETERSBURG,FL 33701. UNIV N CAROLINA,NATL UNDERSEA RES CTR,KEY LARGO,FL 33037. UNIV FLORIDA,DEPT MICROBIOL & CELL SCI,GAINESVILLE,FL 32611. RP PAUL, JH (reprint author), UNIV S FLORIDA,DEPT MARINE SCI,140 7TH AVE S,ST PETERSBURG,FL 33701, USA. NR 15 TC 61 Z9 63 U1 0 U2 8 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 1995 VL 61 IS 6 BP 2230 EP 2234 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA RA621 UT WOS:A1995RA62100024 PM 16535046 ER PT J AU PAUL, JH ROSE, JB JIANG, S KELLOGG, C SHINN, EA AF PAUL, JH ROSE, JB JIANG, S KELLOGG, C SHINN, EA TI OCCURRENCE OF FECAL INDICATOR BACTERIA IN SURFACE WATERS AND THE SUBSURFACE AQUIFER IN KEY-LARGO, FLORIDA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID CLOSTRIDIUM-PERFRINGENS; ENUMERATION; QUALITY; ENTEROCOCCI; VIRUSES; DNA AB Sewage waste disposal facilities in the Florida Keys include septic tanks and individual package plants in place of municipal collection facilities in most locations. In Key Large, both facilities discharge into the extremely porous Key Largo Limestone. To determine whether there was potential contamination of the subsurface aquifer and nearby coastal surface waters by such waste disposal practices, we examined the presence Of microbial indicators commonly found in sewage (fecal coliforms, Clostridium perfringens, and enterococci) and aquatic microbial parameters (viral din:ct counts, bacterial direct counts, chlorophyll a, and marine vibriophage) in injection well effluent, monitoring wells that followed a transect from onshore to offshore, and surface waters above these wells in two separate locations in Key Large in August 1993 and March 1994. Effluent and waters from onshore shallow monitoring wells (1.8- to 3,7-m depth) contained two or all three of the fecal indicators in all three samples taken, whereas deeper wells (10.7- to 12,2-m depth) at these same sites contained few or none. The presence of fec:al indicators was found in two of five nearshore wells (i.e., those that were less than or equal to 1.8 miles [less than or equal to 2.9 km] from shore), whereas offshore wells (greater than or equal to 2.1 to 5.7 miles [less than or equal to 3.4 to 9.2 km] from shore) showed little sign of contamination, Indicators were also found in surface waters in a canal in Key Large and in offshore surface, waters in March but not in August. Collectively, these results suggest that fecal contamination of the shallow onshore aquifer, parts of the nearshore aquifer, and certain surface waters has occurred. Current sewage;waste disposal practices may have contributed to this contamination. C1 US GEOL SURVEY,CTR COASTAL GEOL,ST PETERSBURG,FL 33701. RP PAUL, JH (reprint author), UNIV S FLORIDA,DEPT MARINE SCI,140 7TH AVE S,ST PETERSBURG,FL 33701, USA. RI Kellogg, Christina/B-3257-2009; Jiang, Sunny/H-7702-2012 OI Jiang, Sunny/0000-0002-4993-8038 NR 26 TC 63 Z9 63 U1 1 U2 5 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 1995 VL 61 IS 6 BP 2235 EP 2241 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA RA621 UT WOS:A1995RA62100025 PM 7793943 ER PT J AU VERMETTE, SJ PEDEN, ME WILLOUGHBY, TC LINDBERG, SE WEISS, AD AF VERMETTE, SJ PEDEN, ME WILLOUGHBY, TC LINDBERG, SE WEISS, AD TI METHODOLOGY FOR THE SAMPLING OF METALS IN PRECIPITATION - RESULTS OF THE NATIONAL ATMOSPHERIC DEPOSITION PROGRAM (NADP) PILOT NETWORK SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE TRACE METALS; WET DEPOSITION; PRECIPITATION; NETWORK SAMPLING; NADP ID TRACE-METALS; NATURAL-WATERS; STORAGE AB A pilot network of three U.S. sites was initiated to test the feasibility of quantitating arsenic, cadmium copper, manganese, lead, and zinc in wet deposition, and to make recommendations for a subnetwork at site and training levels compatible with other wet deposition networks, specifically National Atmospheric Deposition Program (NADP). Modifications were made to Aerochem Metric samplers, including use of Teflon(R) surfaces, an insulated enclosure, and a thermostat controlled cooling fan and heater. Inductively coupled plasma mass spectrometry (ICP-MS) is well suited for the routine determination of the targeted metals at the low mu g l(-1) concentrations. Relatively simple cleaning and handling protocols are suitable for measuring metal concentrations at continental levels in precipitation without introducing significant contamination. C1 ILLINOIS STATE WATER SURVEY,CHAMPAIGN,IL 61820. US GEOL SURVEY,INDIANAPOLIS,IN 46278. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. ILLINOIS HAZARDOUS WASTE RES & INFORMAT CTR,CHAMPAIGN,IL 61820. RP VERMETTE, SJ (reprint author), SUNY COLL BUFFALO,1300 ELMWOOD AVE,BUFFALO,NY 14222, USA. NR 20 TC 17 Z9 17 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 1995 VL 29 IS 11 BP 1221 EP 1229 DI 10.1016/1352-2310(94)00207-2 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA RF304 UT WOS:A1995RF30400006 ER PT J AU KRUGER, JM JOHNSON, RA HOUSER, BB AF KRUGER, JM JOHNSON, RA HOUSER, BB TI MIOCENE-PLIOCENE HALF-GRABEN EVOLUTION, DETACHMENT FAULTING AND LATE-STAGE CORE COMPLEX UPLIFT FROM REFLECTION SEISMIC DATA IN SOUTH-EAST ARIZONA SO BASIN RESEARCH LA English DT Article ID ANGLE NORMAL FAULTS; SOUTHEASTERN ARIZONA; PINALENO MOUNTAINS; RANGE PROVINCE; BASIN; NEVADA; STRATIGRAPHY; EXTENSION; DISPLACEMENT; CALIFORNIA AB Reflection seismic data show that the late Cenozoic Safford Basin in the Basin and Range of south-eastern Arizona, is a 4.5-km-deep, NW-trending, SW-dipping half graben composed of middle Miocene to upper Pliocene sediments, separated by a late Miocene sequence boundary into lower and upper basin-fill sequences. Extension during lower basin-fill deposition was accommodated along an E-dipping range-bounding fault comprising a secondary breakaway zone along the north-east flank of the Pinaleno Mountains core complex. This fault was a listric detachment fault, active throughout the mid-Tertiary and late Cenozoic, or a younger fault splay that cut or merged with the detachment fault. Most extension in the basin was accommodated by slip on the range-bounding fault, although episodic movement along antithetic faults temporarily created a symmetric graben. Upper-plate movement over bends in the range-bounding fault created rollover structures in the basin fill and affected deposition within the half graben. Rapid periods of subsidence relative to sedimentation during lower basin-fill deposition created thick, laterally extensive lacustrine or alluvial plain deposits, and restricted proximal alluvian-fan deposits to the basin margins. A period of rapid extension and subsidence relative to sediment influx, or steepening of the upper segment of the range-bounding fault at the start of upper basin-fill deposition resulted in a large downwarp over a major fault bend. Sedimentation was restricted to this downwarp until filled. Episodic subsidence during upper basin-fill deposition caused widespread interbedding of lacustrine and fluvial deposits. Northeastward tilting along the south-western flank of the basin and north-eastward migration of the depocentre during later periods of upper basin-fill deposition suggest decreased extension rates relative to late-stage core complex uplift. C1 UNIV ARIZONA,DEPT GEOSCI,TUCSON,AZ 85721. UNIV ARIZONA,US GEOL SURVEY,TUCSON,AZ 85721. NR 65 TC 9 Z9 9 U1 1 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0950-091X J9 BASIN RES JI Basin Res. PD JUN PY 1995 VL 7 IS 2 BP 129 EP 149 DI 10.1111/j.1365-2117.1995.tb00100.x PG 21 WC Geosciences, Multidisciplinary SC Geology GA RK022 UT WOS:A1995RK02200002 ER PT J AU LANGER, CJ SPENCE, W AF LANGER, CJ SPENCE, W TI THE 1974 PERU EARTHQUAKE SERIES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID INTERMEDIATE-DEPTH EARTHQUAKES; COUPLED SUBDUCTION ZONES; OUTER-RISE EARTHQUAKES; GREAT EARTHQUAKES; TEMPORAL VARIATION; SLAB PULL; RUPTURE; PACIFIC; MAGNITUDES; AMERICA AB The aftershocks of the 3 October 1974, M(W) 8.1 earthquake have been relocated using data from a 10-station temporary seismic network. These aftershocks are among the best-observed of great circum-Pacific subduction earthquakes. Recent modelings of the rupture history of the mainshock, done in other studies, indicate a bilateral rupture on the thrust interface updip to the Peru-Chile Trench. Preseismicity was predominately downdip of the mainshock rupture, consistent with the mainshock's asperities being loaded by sinking of the Nazca plate. The aftershocks, including an M(S) 7.1 event, are located primarily near the downdip periphery of the mainshock's shallow-dipping rupture surface. For a concentration of aftershocks furthest downdip, a composite focal mechanism shows east-trending, right-lateral, strike-slip displacement, corresponding to the dominant moment release of the mainshock being north of the strike-slip deformation. At a depth of 20 to 25 km, the 11 degrees NE-dipping Nazca plate increases in dip to 30 degrees NE. Although a postmainshock episode of plate motion must have bridged both this hinge and the bend at the Peru-Chile Trench, the associated bending moments were aseismic. The Lima Basin is directly over the downdip edge of the shallow-dipping, strongly coupled interface and the aftershocks there, similar in location to basins in outer rises of other regions. The space-time history of the aftershocks shows an alternation between heightened activity in the updip-of-hinge and downdip-of-hinge zones, with many earthquakes near the pending rupture of the 9 November 1974, M(S) 7.1 aftershock, and a regional seismic quiescence following this large aftershock. C1 US GEOL SURVEY, NATL EARTHQUAKE INFORMAT CTR, DENVER, CO 80225 USA. US GEOL SURVEY, EARTHQUAKE & LANDSLIDE HAZARDS BRANCH, DENVER, CO 80225 USA. NR 62 TC 15 Z9 15 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1995 VL 85 IS 3 BP 665 EP 687 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC529 UT WOS:A1995RC52900001 ER PT J AU JONES, LE HOUGH, SE AF JONES, LE HOUGH, SE TI ANALYSIS OF BROAD-BAND RECORDS FROM THE 28 JUNE 1992 BIG-BEAR EARTHQUAKE - EVIDENCE OF A MULTIPLE-EVENT SOURCE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN-CALIFORNIA; LANDER EARTHQUAKE; SEQUENCE; STRESS; INVERSION; FAULTS; VALLEY; APRIL AB The 28 June 1992 Big Bear earthquake occurred at 15:05:21 GMT and is considered to be an aftershock of the earlier M(W) = 7.3 Landers earthquake. From overall aftershock locations and long-period focal studies, rupture is generally assumed to have propagated northeast. No surface rupture was found, however, and the mainshock locations determined from both strong motion and TERRAscope data. are mutually consistent and do not Lie on the assumed fault plane. Further, directivity analysis of records from the TERRAscope array suggests significant short- and long-period energy propagating northwest along the presumed antithetic fault plane. This observation is supported by significant early aftershocks distributed along both the presumed rupture plane and the antithetic plane to the northwest. An empirical Green's function (eGf) approach using both the M(W) 5.2, 28 June 1992 14:43 GMT foreshock and the M(W) = 5.0 17 August 1992 aftershock produces consistent results and suggests that the Big Bear event comprised at least two substantial subevents. From the eGf results, we infer that the second and possibly a third subevent occurred on the presumed (northeast striking) mainshock rupture surface, but that significant moment release occurred on the antithetic northwest striking surface. We present results from line-source fault modeling of broadband displacement recordings of the Big Bear mainshock, which indicate that a two-fault event is necessary to produce the observed waveforms. The limitations imposed by the mainshock location and directivity analysis require that the initial rupture be towards the northwest, striking 320 degrees. This was followed approximately 4 sec later by bilateral rupture along a northeast-southwest fault that strikes 50 degrees east of north. C1 US GEOL SURVEY,PASADENA,CA 91006. RP JONES, LE (reprint author), CALTECH,SEISMOL LAB,PASADENA,CA 91125, USA. NR 32 TC 25 Z9 26 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1995 VL 85 IS 3 BP 688 EP 704 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC529 UT WOS:A1995RC52900002 ER PT J AU JOHNSTON, MJS HILL, DP LINDE, AT LANGBEIN, J BILHAM, R AF JOHNSTON, MJS HILL, DP LINDE, AT LANGBEIN, J BILHAM, R TI TRANSIENT DEFORMATION DURING TRIGGERED SEISMICITY FROM THE 28 JUNE 1992 M(W)=7.3 LANDERS EARTHQUAKE AT LONG-VALLEY VOLCANIC CALDERA, CALIFORNIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EASTERN CALIFORNIA; HALF-SPACE; PRESSURE; SYSTEMS; RESERVOIR; WATER AB Continuous records from a borehole strainmeter and a long baseline tiltmeter in the Long Valley caldera provide critical insights into the origin of at least one episode of minor seismicity in volcanic regions triggered by the 28 June 1992, M(L) 7.3 Landers, California, earthquake. A strain transient reaching a peak of 0.25 microstrain occurred in the few days following the Landers event and decayed over the next 20 days. A tilt perturbation during the same time reached a peak amplitude of 0.2 microradians. These signals correspond approximately in time to the primary seismic moment release across a 50 km(2) region of the south part of the caldera at depths between 2 and 10 km. Corresponding strain transients in 5-km geodetic lines across the south caldera are not apparent above the 95% confidence limits of about 0.4 microstrain in daily sampled data during this same period. These data rule out models involving single localized inflation sources within the upper crust beneath the caldera, including that responsible for the current rapid inflation of the resurgent dome. They also preclude models involving aseismic slip on single strike-slip or normal faults in the caldera. A single source in the form of a relaxing magma body at a depth of 50 km beneath the caldera can account for the deformation data, but whether the small stress changes are sufficient to drive the triggered seismicity is not clear. An alternate possibility involves distributed deformational sources triggered by the passage of the 10 microstrain peak amplitude surface waves from the earthquake. This distributed deformational source could result either from rupturing of overpressured fluid or gas chambers commonly encountered in volcanic regions or from advective gas overpressure during release of gas bubbles in hydrothermal or magmatic fluids. C1 CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,WASHINGTON,DC 20015. UNIV COLORADO,CIRES,BOULDER,CO 80309. RP JOHNSTON, MJS (reprint author), US GEOL SURVEY,MS977,MENLO PK,CA 94025, USA. OI Bilham, Roger/0000-0002-5547-4102 NR 35 TC 30 Z9 30 U1 0 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1995 VL 85 IS 3 BP 787 EP 795 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC529 UT WOS:A1995RC52900009 ER PT J AU ATKINSON, GM HANKS, TC AF ATKINSON, GM HANKS, TC TI A HIGH-FREQUENCY MAGNITUDE SCALE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EASTERN NORTH-AMERICA; STRONG GROUND MOTION; EARTHQUAKES; ATTENUATION; SPECTRA; ACCELERATION; DEFORMATION; CALIFORNIA; SEISMICITY; MODEL AB A high-frequency magnitude scale (m) is proposed: m = 2 log a(hf) + 3, where a(hf) is the high-frequency level of the Fourier amplitude spectrum of acceleration in cm/sec (average or random horizontal component), at a hypocentral or closest fault distance of 10 km. m can be determined from either instrumental data or the felt area of an earthquake. The definition of m has been arranged such that m = M (moment magnitude) for events of ''average'' stress drop, in both eastern North America (ENA) and California. m provides a measure of the stress drop if M is also known. The observed relationship between m and M indicates that the average stress drop is about 150 bars for ENA earthquakes, and about 70 bars for California earthquakes. The variability of stress drop is much larger in ENA than in California. The chief justification for the m scale is its utility in the interpretation of the large preinstrumental earthquakes that are so important to seismic hazard estimation in eastern North America. For such events, m can be determined more reliably than can M or m(N) (Nuttli magnitude), and forms a much better basis for estimating high-frequency ground motions. When used as a pair, m and M provide a good index of ground motion over the entire engineering frequency band. If both of these magnitudes can be defined for an earthquake then a ground-motion model, such as the stochastic model, can be used to obtain reliable estimates of response spectra and peak ground motions. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP CARLETON UNIV, DEPT EARTH SCI, OTTAWA, ON K1S 5B6, CANADA. NR 31 TC 27 Z9 28 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1995 VL 85 IS 3 BP 825 EP 833 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RC529 UT WOS:A1995RC52900013 ER PT J AU RICHTER, DH PREECE, SJ MCGIMSEY, RG WESTGATE, JA AF RICHTER, DH PREECE, SJ MCGIMSEY, RG WESTGATE, JA TI MOUNT-CHURCHILL, ALASKA - SOURCE OF THE LATE HOLOCENE WHITE RIVER ASH SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article AB Although the White River Ash was first recognized by F. Schwatka in 1883, the source of this widespread bilobate Plinian deposit in northwestern Canada and adjoining eastern Alaska has not been definitively identified. Recent investigations disclose that Mount Churchill, in the St. Elias Mountains of south-central Alaska, contains a summit crater whose rim is chiefly composed of ash, coarse pumice, and exotic rock fragments. The pumice clasts decrease in size and the exotic rock fragments disappear with increasing distance from the summit area. Pumice from the Mount Churchill summit, and from the White River Ash deposits up to 25 km from the summit area, are mineralogically and chemically similar. Microprobe analyses of the summit pumice glass are virtually identical to those of more distant proximal White River Ash glass. Fe-Ti oxide compositions in the Mount Churchill proximal tephra indicate that all tephra sampled during this study is from the younger, eastern lobe of the White River Ash. These field and laboratory data demonstrate that Mount Churchill is a Holocene volcano and the source of the eastern lobe of the White River Ash. Glass compositions and distribution patterns, however, indicate both lobes of the ash have a common source. C1 MIAMI UNIV, DEPT GEOL, OXFORD, OH 45056 USA. US GEOL SURVEY, ALASKA VOLCANO OBSERV, ANCHORAGE, AK 99508 USA. UNIV TORONTO, DEPT GEOL, TORONTO, ON M5S 3B1, CANADA. RP RICHTER, DH (reprint author), US GEOL SURVEY, ALASKAN GEOL BRANCH, 4200 UNIV DR, ANCHORAGE, AK 99508 USA. NR 14 TC 30 Z9 30 U1 0 U2 2 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD JUN PY 1995 VL 32 IS 6 BP 741 EP 748 DI 10.1139/e95-063 PG 8 WC Geosciences, Multidisciplinary SC Geology GA RR087 UT WOS:A1995RR08700006 ER PT J AU NELSON, ME AF NELSON, ME TI WINTER RANGE ARRIVAL AND DEPARTURE OF WHITE-TAILED DEER IN NORTHEASTERN MINNESOTA SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID MOVEMENTS AB I analyzed 364 spring and 239 fall migrations by 194 white-tailed deer (Odocoileus virginianus) from 1975 to 1993 in northeastern Minnesota to determine the proximate cause of arrivals on and departures from winter ranges. The first autumn temperatures below -7 degrees C initiated fall migrations for 14% (95% confidence interval (CI) = 0-30) of female deer prior to snowfall in three autumns, but only 2% remained on winter ranges. During 14 autumns, the first temperatures below -7 degrees C coincidental with snowfalls elicited migration in 45% (95% CI = 34-57) of females, and 91% remained on winter ranges. Arrival dates failed to correlate with independent variables of temperature and snow depth, precluding predictive modeling of arrival on winter ranges. During 13 years, a mean of 80% of females permanently arrived on winter ranges by 31 December. Mean departure dates from winter ranges varied annually (19 March-4 May) and between winter ranges (14 days) and according to snow depth (15-cm differences). Only 15-41% of deer departed when snow depths were > 30 cm but 80% had done so by the time of 10-cm depths. Mean weekly snow depths in March (18-85 cm) and mean temperature in April (0.3-8.1 degrees C) explained most of the variation in mean departure dates from two winter ranges (Ely, R(2) = 0.87, P < 0.0005, n = 19 springs; Isabella, R(2) = 0.85, P = 0.0001, n = 12 springs). Mean differences between observed mean departure dates and mean departure dates predicted from equations ranged from 3 days (predictions within the study area) to 8 days (predictions for winter ranges 100-440 km distant). C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,NATL BIOL SURVEY,LAUREL,MD 20708. NR 28 TC 54 Z9 58 U1 2 U2 23 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUN PY 1995 VL 73 IS 6 BP 1069 EP 1076 DI 10.1139/z95-127 PG 8 WC Zoology SC Zoology GA RX214 UT WOS:A1995RX21400008 ER PT J AU ALBINO, GV AF ALBINO, GV TI IRON-RICH AND ALUMINUM-RICH SERPENTINE AND CHLORITE FROM THE BOUNDARY ULTRAMAFIC COMPLEX, CAPE-SMITH BELT, NEW-QUEBEC SO CANADIAN MINERALOGIST LA English DT Article DE LIZARDITE; ANTIGORITE; CHRYSOTILE; CHLORITE; ALUMINOUS SERPENTINE; SERPENTINIZATION; PERIDOTITE; ELECTRON-MICROPROBE ANALYSES; CAPE SMITH BELT; NEW QUEBEC ID NORTHERN QUEBEC; METAMORPHISM; CHRYSOTILE; PERIDOTITE; STABILITY; UNGAVA; ROCKS AB Iron- and aluminum-rich serpentines (maximum 15.8% Al2O3 and 17.1% FeO, by weight) are common in the Boundary ultramafic complex, a komatiitic intrusive-extrusive body in the eastern part of the Aphebian Cape Smith Belt, northern Quebec. Most of the pervasive serpentinization occurred during peak (biotite-grade) metamorphism, which was contemporaneous with regional thrusting. Later retrogression, locally accompanied by CO2 metasomatism, was associated with later phases of deformation. Early-formed serpentines are typically pseudomorphic, whereas later serpentines include interpenetrating or vein antigorite and, lastly, vein chrysotile. Formation of the nonpseudomorphic serpentine textures is associated with other features indicative of element migration, including tremolitization of serpentine, serpentinization of clinopyroxene, and replacement of sulfides by silicates, and vice versa. Aluminum contents of lizardite are variable; nonpseudomorphic multilayer varieties have the highest Al contents. In contrast to the highly variable compositions of the serpentine-group minerals, chlorite compositions are relatively constant (Fe-rich clinochlore). Elevated abundance of Fe is most clearly associated with sulfide accumulations. Formation of Al- and Fe-enriched serpentine may be a function of the relatively aluminous bulk-composition (as much as 10 wt.% Al2O3) of the komatiitic rocks, and a later metamorphic history that involved considerable migration of elements on a local scale. C1 UNIV NEVADA, MACKAY SCH MINES, US GEOL SURVEY, RENO FIELD OFF, RENO, NV 89557 USA. NR 34 TC 4 Z9 4 U1 0 U2 2 PU MINERALOGICAL ASSOC CANADA PI QUEBEC PA 490, RUE DE LA COURONNE, QUEBEC, QC G1K 9A9, CANADA SN 0008-4476 EI 1499-1276 J9 CAN MINERAL JI Can. Mineral. PD JUN PY 1995 VL 33 BP 559 EP 568 PN 3 PG 10 WC Mineralogy SC Mineralogy GA RQ599 UT WOS:A1995RQ59900005 ER PT J AU CAICCO, SL SCOTT, JM BUTTERFIELD, B CSUTI, B AF CAICCO, SL SCOTT, JM BUTTERFIELD, B CSUTI, B TI A GAP ANALYSIS OF THE MANAGEMENT STATUS OF THE VEGETATION OF IDAHO (USA) SO CONSERVATION BIOLOGY LA English DT Article ID BIOLOGICAL DIVERSITY; CONSERVATION; FIRE AB We compiled a 1:500,000-scale map of the actual vegetation of the state of Idaho from existing vegetation maps, LANDSAT MSS satellite imagery and aerial photography An accuracy assessment showed 92.7% of the polygons to be correctly classified. The map was digitized as a layer in a Geographic Information System (GIS) using ARC/INFO software. Land ownership was also digitized from existing maps. Ownership tracts were assigned a protection level based on opportunities provided for management for conservation of biological diversity. We then compared the vegetation and management status layers to assess the extent and degree of protection afforded to 71 vegetation and land-use categories. We identified sir vegetation complexes with no protection and five vegetation complexes for which protection is less than 1000 ha each. An additional 18 vegetation types have total protection in the ranges between 1001-5000 ha and 5001-10,000 ha Most of these 29 vegetation types are shrub-steppe complexes or conifer/steppe mosaics. Economically valuable montane forests of western redcedar, western hemlock: and grand fir, as well as subalpine woodlands and forests of mountain hemlock, are also poorly represented in protected areas. Most opportunity for increasing protection of these types lies on land managed by federal agencies. Other trends in the data include poor geographic representation, small area of individual protected occurrences relatively good protection in Idaho but less outside of the state, and protection poor in Idaho but widespread elsewhere The major limitation of our analysis is a lack of detail on the ecological status of vegetation types. Information on the structure of the forest types as well as data on the understory composition of the shrub-steppe complexes are lacking. Our study shows gap analysis to be an efficient and useful method of assessing the extent and degree of protection of land-cover types and associated biodiversity over an area exceeding 200,000 km(2). C1 IDAHO DEPT FISH & GAME,IDAHO NAT HERITAGE PROGRAM,BOISE,ID 83707. UNIV IDAHO,US FISH & WILDLIFE SERV,IDAHO COOPERAT FISH & WILDLIFE RES UNIT,MOSCOW,ID 83843. NR 47 TC 56 Z9 57 U1 1 U2 7 PU BLACKWELL SCIENCE PUBL INC CAMBRIDGE PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD JUN PY 1995 VL 9 IS 3 BP 498 EP 511 DI 10.1046/j.1523-1739.1995.09030498.x PG 14 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA RB704 UT WOS:A1995RB70400009 ER PT J AU HEDRICK, PW HEDGECOCK, D HAMELBERG, S AF HEDRICK, PW HEDGECOCK, D HAMELBERG, S TI EFFECTIVE POPULATION-SIZE IN WINTER-RUN CHINOOK SALMON SO CONSERVATION BIOLOGY LA English DT Article ID FAMILY-SIZE; CONSERVATION; HATCHERY AB Winter-run chinook salmon from the Sacramento River, California, is federally listed as endangered Since 1989 there has been a program to augment the natural population by capturing adults, artificially spawning them, raising the young, and releasing the smelt. Here we estimate the effective population size of these captive-raised fish, the natural run, and the combination of both groups over the three-year period from 1991 to 1993. We find that the most appropriate estimate of the effective population size of the captive-raised progeny is a variance estimate of effective population size standardized so that the number of released smelts returning to spawn was the same as the number of spawners used to produce the smelts originally. We have generated 10,000 random samples to simulate returns from these released progeny. The estimates of the effective population sizes in 1991, 1992, and 1993 were only 7.02, 19.07, and 7.74, respectively. We then determined limits on the effective population size of the natural run based on 0.1 and 0.333 of the run-size estimates. Using estimates of the captive proportion of the run, the minimum estimates of the effective population size of the overall run for the three years were 21.9, 127.3, and 39.0, and the maximum estimates were 61.6, 401.0, and 108.7. It does not appear that the hatchery program has reduced the overall effective population size. The run sizes in each year are extremely low, however, and it is possible that fish will be lost from this run in one of the years in the immediate future, making reestablishment of a healthy run even more difficult. C1 UNIV CALIF DAVIS,BODEGA MARINE LAB,BODEGA BAY,CA 94923. US FISH & WILDLIFE SERV,RED BLUFF,CA 96080. RP HEDRICK, PW (reprint author), ARIZONA STATE UNIV,DEPT ZOOL,TEMPE,AZ 85281, USA. RI Hedgecock, Dennis/I-8655-2012 OI Hedgecock, Dennis/0000-0002-3995-646X NR 20 TC 48 Z9 49 U1 0 U2 11 PU BLACKWELL SCIENCE PUBL INC CAMBRIDGE PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD JUN PY 1995 VL 9 IS 3 BP 615 EP 624 DI 10.1046/j.1523-1739.1995.09030615.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA RB704 UT WOS:A1995RB70400019 ER PT J AU COLEMAN, DS GLAZNER, AF MILLER, JS BRADFORD, KJ FROST, TP JOYE, JL BACHL, CA AF COLEMAN, DS GLAZNER, AF MILLER, JS BRADFORD, KJ FROST, TP JOYE, JL BACHL, CA TI EXPOSURE OF A LATE CRETACEOUS LAYERED MAFIC-FELSIC MAGMA SYSTEM IN THE CENTRAL SIERRA-NEVADA BATHOLITH, CALIFORNIA SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID LAMARCK GRANODIORITE; ZIRCON; STRONTIUM; LEAD; PB; CRYSTALLIZATION; GEOCHRONOLOGY; GRANITOIDS; EVOLUTION; ROCKS AB New U-Pb zircon ages for the Lamarck Granodiorite, associated synplutonic gabbro and diorite plutons, and two large mafic intrusive complexes that underlie them in the Sierra Nevada batholith are 92+/-1 Ma. These ages establish the Late Cretaceous as a period of extensive mafic-felsic magmatism in the central part of the batholith, and confirm the significance of mafic magmatism in the evolution of the voluminous silicic plutons in the Sierran are. The lack of significant zircon inheritance in any of the units analyzed supports isotopic evidence that the Lamarck and other Late Cretaceous Sierran plutons were derived predominantly from young crust. Recognition of an extensive mafic-felsic magma system in the Sierra Nevada batholith emphasizes the importance of basaltic liquids in the evolution of continental crust in are settings. C1 UNIV N CAROLINA,DEPT GEOL,CHAPEL HILL,NC 27599. US GEOL SURVEY,SPOKANE,WA 99201. RP COLEMAN, DS (reprint author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI 541126,CAMBRIDGE,MA 02139, USA. NR 37 TC 64 Z9 64 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD JUN PY 1995 VL 120 IS 2 BP 129 EP 136 DI 10.1007/BF00287110 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA RG375 UT WOS:A1995RG37500002 ER PT J AU SANFORD, WE STEENHUIS, TS PARLANGE, JY SURFACE, JM PEVERLY, JH AF SANFORD, WE STEENHUIS, TS PARLANGE, JY SURFACE, JM PEVERLY, JH TI HYDRAULIC CONDUCTIVITY OF GRAVEL AND SAND AS SUBSTRATES IN ROCK-REED FILTERS SO ECOLOGICAL ENGINEERING LA English DT Article DE CONSTRUCTED WETLANDS; LANDFILL LEACHATE; HYDRAULIC CONDUCTIVITY; SUBSURFACE FLOW ID ROOT-ZONE METHOD; WASTE-WATER; WETLAND AB Long-term use of a constructed wetland to treat landfill leachate requires that the saturated hydraulic conductivity be maintained and clogging avoided to prevent overland now, which bypasses the treatment process. This paper describes the application of an equation developed for prediction of cumulative drainage volume from hillslopes to measure the saturated hydraulic conductivity (K-s) of substrates used in rock-reed filters. Outflow was measured at five intervals during the first 26 months of operation. The values of K-s obtained by the drainage equation compared favorably with values calculated from a more difficult method based on Darcy's law. Results indicate that the finest substrate (a sand-and-gravel mixture) became almost completely clogged, and that the presence of reeds (Phragmites australis) did not maintain or increase the conductivity. Hydraulic conductivity of pea-gravel (0.5-cm diameter) and coarse-gravel (3-cm diameter) substrates with reeds did decrease in the 26-month period. C1 UNIV TENNESSEE,DEPT CIVIL & ENVIRONM ENGN,KNOXVILLE,TN 37996. CORNELL UNIV,DEPT AGR & BIOL ENGN,ITHACA,NY 14853. US GEOL SURVEY,ITHACA,NY 14850. CORNELL UNIV,DEPT SOIL CROP & ATMOSPHER SCI,ITHACA,NY 14853. RP SANFORD, WE (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS 6352,OAK RIDGE,TN 37831, USA. RI Sanford, William/F-7380-2016 OI Sanford, William/0000-0001-9085-1367 NR 16 TC 32 Z9 34 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD JUN PY 1995 VL 4 IS 4 BP 321 EP 336 DI 10.1016/0925-8574(95)00004-3 PG 16 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA RK650 UT WOS:A1995RK65000006 ER PT J AU SYMONS, DTA SANGSTER, DF LEACH, DL AF SYMONS, DTA SANGSTER, DF LEACH, DL TI A TERTIARY AGE FROM PALEOMAGNETISM FOR MISSISSIPPI VALLEY-TYPE ZINC-LEAD MINERALIZATION IN UPPER SILESIA, POLAND SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID STRATABOUND ORE-DEPOSITS; THEORETICAL-ANALYSIS; SOUTHEAST MISSOURI; GROUNDWATER-FLOW; MAGNETITE; GENESIS; REMAGNETIZATION; MAGNETIZATION AB Ore and host rocks of the Middle Triassic Muschelkalk carbonates were sampled at 35 sites in three operating mines and several quarries in the Cracow Silesia Mississippi Valley-type district of southern Poland. Paleomagnetic analysis was done using alternating field and thermal step demagnetization and saturation isothermal remanence tests. Specimens from three limestone and two early dolomite sites retain a dual-polarity A remanent magnetization component (D = 43 degrees I = 51 degrees, k = 40, alpha(95) = 12 degrees) which yields a Middle to Upper Triassic pole. A resides in single domain to pseudosingle domain magnetite in limestone and is probably primary, and. in single domain-pseudosingle domain magnetite and hematite in early dolomite and is probably diagenetic. Two limestone sites carry a Tertiary remagnetization and most early dolomite sites carry a partial Tertiary remagnetization, or hybrid remanence, identified by paleomagnetic fold and breccia tests. Late dolomite and Mississippi Valley-type mineralization from 14 sites retain a dual-polarity C remanence component (D = 3 degrees, I = 66 degrees, k = 34, alpha(95) = 7 degrees), which defines a Tertiary pole position. Conglomerate and breccia tests confirm that the clasts in late dolomite were remagnetized. The Tertiary age for the Mississippi Valley-type ore deposits is within the post-mid-Jurassic to pre-Miocene window permitted by the geologic evidence for mineralization. The age also supports gravity-driven fluid Bow models for ore genesis that are associated with the Alpine orogeny. The dual polarities and elongate distribution of site mean directions suggest a 1 to 20 m.y. duration for the late dolomitization and mineralization event. C1 GEOL SURVEY CANADA,OTTAWA,ON K1A 0E8,CANADA. US GEOL SURVEY,DENVER,CO 80225. RP SYMONS, DTA (reprint author), UNIV WINDSOR,DEPT GEOL,WINDSOR,ON N9B 3P4,CANADA. NR 71 TC 33 Z9 37 U1 0 U2 3 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JUN-JUL PY 1995 VL 90 IS 4 BP 782 EP 794 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ671 UT WOS:A1995RZ67100005 ER PT J AU ARRIBAS, A CUNNINGHAM, CG RYTUBA, JJ RYE, RO KELLY, WC PODWYSOCKI, MH MCKEE, EH TOSDAL, RM AF ARRIBAS, A CUNNINGHAM, CG RYTUBA, JJ RYE, RO KELLY, WC PODWYSOCKI, MH MCKEE, EH TOSDAL, RM TI GEOLOGY, GEOCHRONOLOGY, FLUID INCLUSIONS, AND ISOTOPE GEOCHEMISTRY OF THE RODALQUILAR GOLD ALUNITE DEPOSIT, SPAIN SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID ACID-SULFATE ALTERATION; AU-AG DEPOSIT; HYDROTHERMAL SYSTEMS; MAGMATIC FLUIDS; ORE-DEPOSITS; PUEBLO-VIEJO; MINERALIZATION; EVOLUTION; PRESSURE; GENESIS AB The Rodalquilar epithermal Au alunite deposit occurs within the Rodalquilar caldera complex in the Miocene Cabo de Gata volcanic field in southeastern Spain. The Rodalquilar caldera formed by eruption of the rhyolitic Cinto ash-flow tuff at about 11 Ma; continued resurgence of the core of the caldera resulted in structural doming and was followed by emplacement of large ring domes, eruption of the Lazaras ash-flow tuff, and development of the smaller, nested Lomilla caldera. Hydrothermal circulation associated with the emplacement of shallow hornblende andesitic intrusions late in the evolution of the caldera led to formation of the epithermal deposits along fractures related to multistage caldera collapse and resurgence. Ore deposits within the Rodalquilar caldera complex consist of low-sulfidation Pb-Zn-(Cu-Ag-Au) quartz veins and the economically most important high-sulfidation Au-(Cu-Te-Sn) ores. The latter are enclosed in areas of acid sulfate alteration present on the east margin of the Lomilla caldera. Drilling indicates that hydrothermally altered rocks are present to depths of > 900 m, with a gradational change with depth from silicic, Ito advanced argillic, to intermediate argillic, to sericitic zones; an envelope of propylitic alteration surrounds these zones. The sericitic zone is present at depths > 400 m and occurs under the advanced argillic (stage 1 alunite, diaspore, zunyite, pyrophyllite) and silicic (vuggy silica and massive silicified rock) zones, which are well developed to present depths of similar to 300 and 100 m, respectively. Vuggy silica and massive silicified rock are structurally controlled and spatially related to the Au deposits. K/Ar dating of stage 1 alunite and hydrothermal illite indicates an age of mineralization of about 10.4 Ma. The results of paragenetic, fluid inclusion, and stable isotope studies indicate an evolution of the hydrothermal system, consisting of an early period of acidic wall-rock alteration and a late period of Au mineralization. A significant magmatic fluid component was present throughout, contributing acidity in the form of H2SO4 and HCl. Salinities in some samples of deep, hot (> 400 degrees C) fluids exceeded 40 wt percent NaCl equiv, consistent with the presence of a magmatic brine. In addition, the O and H isotope ratios of hypogene alteration minerals (alunite, kaolinite, sericite, and hydrothermal quartz) indicate that hydrothermal fluids (delta(18)O = 7 +/- 3 parts per thousand, delta D = -20 +/- 10 parts per thousand) during the main period of wall-rock alteration were dominantly magmatic in origin. The delta(34)S(Sigma S) was similar to 9 per mil and H2S/SO4 of the bulk hydrothermal system during acidic alteration was similar to 5. The delta(34)S values of stage 1 alunite (22.3-31.0 parts per thousand) and pyrite (0.3-8.0 parts per thousand) in the advanced argillic zone reflect isotopic equilibrium between sulfate and sulfide at T = 220 degrees to 330 degrees C, with the lower values corresponding with present-day surface samples. C1 UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. US GEOL SURVEY,NATL CTR,RESTON,VA 22092. US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 69 TC 136 Z9 139 U1 1 U2 27 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JUN-JUL PY 1995 VL 90 IS 4 BP 795 EP 822 PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RZ671 UT WOS:A1995RZ67100006 ER PT J AU BACK, W AF BACK, W TI WATER MANAGEMENT BY EARLY PEOPLE IN THE YUCATAN, MEXICO SO ENVIRONMENTAL GEOLOGY LA English DT Article DE GROUNDWATER MANAGEMENT; WATER SUPPLIES; KARSTIFICATION; YUCATAN AB The Yucatan Peninsula is a coastal plain underlain by permeable limestone and receives abundant rainfall. Such hydrogeologic conditions should provide major supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that limits the amount of fresh water available. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed on extensive use of groundwater. The religion was water oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management, primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supply by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution. A historical perspective of a paper such as this provides insight into the attitudes concerning water of early people and perhaps provides insight into current attitudes concerning water. Hydrogeologists possess the expertise to generate relevant information required by water managers to arrive at management programs to achieve sustainable development. RP BACK, W (reprint author), US GEOL SURVEY,431 JOHN WESLEY POWELL BLDG,RESTON,VA 22092, USA. NR 2 TC 8 Z9 8 U1 0 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD JUN PY 1995 VL 25 IS 4 BP 239 EP 242 PG 4 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA RG945 UT WOS:A1995RG94500004 ER PT J AU BACK, W AF BACK, W TI CONCEPT OF HYDROLOGIC TIME SO ENVIRONMENTAL GEOLOGY LA English DT Note RP BACK, W (reprint author), US GEOL SURVEY,431 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD JUN PY 1995 VL 25 IS 4 BP 277 EP 277 PG 1 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA RG945 UT WOS:A1995RG94500010 ER PT J AU CAPEL, PD MA, L SCHROYER, BR LARSON, SJ GILCHRIST, TA AF CAPEL, PD MA, L SCHROYER, BR LARSON, SJ GILCHRIST, TA TI ANALYSIS AND DETECTION OF THE NEW CORN HERBICIDE ACETOCHLOR IN RIVER WATER AND RAIN SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Note C1 UNIV MINNESOTA,GRAY FRESHWATER BIOL INST,NAVARRE,MN 55392. RP CAPEL, PD (reprint author), US GEOL SURVEY,GRAY FRESHWATER BIOL INST,DIV WATER RESOURCES,NAVARRE,MN 55392, USA. NR 7 TC 25 Z9 25 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1995 VL 29 IS 6 BP 1702 EP 1705 DI 10.1021/es00006a039 PG 4 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA RB131 UT WOS:A1995RB13100056 PM 22276898 ER PT J AU WICKER, AM ENDRES, KM AF WICKER, AM ENDRES, KM TI RELATIONSHIP BETWEEN WATERFOWL AND AMERICAN COOT ABUNDANCE WITH SUBMERSED MACROPHYTIC VEGETATION IN CURRITUCK SOUND, NORTH-CAROLINA SO ESTUARIES LA English DT Article AB Waterfowl and American coot data collected from aerial censusing on Currituck Sound were compared during three periods: before Eurasian watermilfoil (Myriophyllum spicatum) colonization (1961-1965); during Eurasian watermilfoil infestation (1968-1977); and following the near absence of submersed macrophytic vegetation after Eurasian watermilfoil decline (1981-1990). Numbers of dabbling ducks (Anas rubripes, Anas platyrhynchos, Anas acuta, Anas americana, Anas crecca), ring-necked ducks (Aythya collaris), and American coot (Fulica americana) were significantly different in Currituck Sound (p < 0.05) in at least two of these periods and were highest during Eurasian watermilfoil infestation. These species also constituted higher percentages of the Atlantic Flyway counts during: Eurasian watermilfoil infestation than in periods before or after. Numbers of snow geese (Chen caerulescens), Canada geese (Branta canadensis), and canvasbacks (Aythya valisneria) were significantly different between periods; however, these birds exhibited a consistent decline from the early to the late period. This study suggests that submersed macrophytes, specifically Eurasian watermilfoil, support increased numbers of dabbling ducks, ring-necked ducks, and American coot. RP WICKER, AM (reprint author), US FISH & WILDLIFE SERV,POB 33726,RALEIGH,NC 27636, USA. NR 15 TC 7 Z9 7 U1 4 U2 10 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD JUN PY 1995 VL 18 IS 2 BP 428 EP 431 DI 10.2307/1352325 PG 4 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA RF762 UT WOS:A1995RF76200013 ER PT J AU SCHOELLHAMER, DH AF SCHOELLHAMER, DH TI SEDIMENT RESUSPENSION MECHANISMS IN OLD-TAMPA BAY, FLORIDA SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE SEDIMENT TRANSPORT; WAVES; TIDES; ESTUARIES; OLD TAMPA BAY, FLORIDA ID BOTTOM BOUNDARY-LAYER; CONTINENTAL-SHELF; FIELD OBSERVATIONS; BED ROUGHNESS; COMBINED WAVE; SHEAR-STRESS; CALIFORNIA; EROSION; MOTION; FLOW AB The mechanisms that resuspend bottom sediments in Old Tampa Bay, a shallow, microtidal, subtropical estuary in west-central Florida, were determined by analysing data collected during several periods from 1988 to 1990. Hydrodynamic and suspended-solids concentration data were collected at a relatively deep (4 m) site where a permanent platform was built and at a relatively shallow (1.5 m) site where a submersible instrument package was deployed. Bottom sediments were non-cohesive silts and fine sands. The primary sediment resuspension mechanism at both sites was wind waves, which were generated by strong and sustained winds associated with winter storms and tropical storms. At the platform, waves were depth-transitional, and estimated bottom shear stresses were most sensitive to wave period and water depth. Concentrations of suspended solids at this site corresponded well with wave motion, and non-linear wave-current interaction was small. At the shallow-water site, concentrations of suspended solids were elevated during periods of strong north-easterly winds and large bottom orbital velocities. At both sites, wind direction was an important factor in determining the occurrence and magnitude of sediment resuspension. Resuspended sediments settled within several hours as storm intensity diminished. Winds and waves generated by thunderstorms were more transient than those generated by winter storms and tropical storms. Based on the data collected during this study, thunderstorms are less likely to resuspend bottom sediment than winter storms and tropical storms. Maximum tidal currents at the study sites are usually less than 15 cm s(-1) and did not increase observed concentrations of suspended solids. RP SCHOELLHAMER, DH (reprint author), US GEOL SURVEY, 2800 COTTAGE WAY, ROOM W-2233, SACRAMENTO, CA 95825 USA. NR 34 TC 48 Z9 51 U1 0 U2 7 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD JUN PY 1995 VL 40 IS 6 BP 603 EP 620 DI 10.1006/ecss.1995.0041 PG 18 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA RG007 UT WOS:A1995RG00700001 ER PT J AU TATE, CM HEINY, JS AF TATE, CM HEINY, JS TI THE ORDINATION OF BENTHIC INVERTEBRATE COMMUNITIES IN THE SOUTH PLATTE RIVER BASIN IN RELATION TO ENVIRONMENTAL-FACTORS SO FRESHWATER BIOLOGY LA English DT Article ID STREAM MACROINVERTEBRATE COMMUNITIES; RUNNING-WATER SITES; GREAT-BRITAIN; CLASSIFICATION; PATTERNS; CATCHMENT; ASSEMBLAGES; PERSPECTIVE; PREDICTION; CONTINUUM AB 1. Spatial patterns of benthic-invertebrate communities were examined in the 62 900 km(2) South Platte River Basin in Colorado, Nebraska and Wyoming, U.S.A., to determine major environmental factors associated with invertebrate distribution. Stable substrates were sampled semiquantitatively for invertebrates from 27 July to 7 August 1992, at twenty-one sites. Data on physical and chemical variables were collected concurrently at each site. 2. Four site groups were identified using detrended correspondence analysis (DCA), one in the mountains and three in the plains (braided channels, tributaries near the confluence with the main stem, and sites affected by effluent from wastewater-treatment plants). DCA axis 1 separated sites into the two major ecoregions (Southern Rocky Mountains and Western High Plains), and regression of DCA axis 1 with environmental variables indicated significant relationships primarily with slope, water temperature, specific conductance, and concentrations of organic nitrogen + ammonia and total phosphorus in surface water. Regression of DCA axis 2 with environmental variables indicated significant relationships with channel width and concentrations of nitrate + nitrite in surface water. 3. Invertebrate community composition and structure varied between ecoregions with greater number of taxa and number of insect families in mountain streams than in plains streams. Within an ecoregion, land use affected the invertebrate community. 4. Factors affecting invertebrate community distribution in stream ecosystems are scale dependent. RP TATE, CM (reprint author), US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,BOX 25046,MS 415,DENVER,CO 80225, USA. NR 43 TC 76 Z9 80 U1 1 U2 20 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0046-5070 J9 FRESHWATER BIOL JI Freshw. Biol. PD JUN PY 1995 VL 33 IS 3 BP 439 EP 454 DI 10.1111/j.1365-2427.1995.tb00405.x PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA RE178 UT WOS:A1995RE17800010 ER PT J AU TORIGOYEKITA, N TATSUMOTO, M MEEKER, GP YANAI, K AF TORIGOYEKITA, N TATSUMOTO, M MEEKER, GP YANAI, K TI THE 4.56 GA U-PB AGE OF THE MET-78008 UREILITE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SM-ND; RB-SR; TH-PB; ISOTOPIC SYSTEMATICS; ANTARCTIC UREILITES; ORIGIN; EVOLUTION; METEORITES; ALLENDE; LEAD AB The U-Th-Pb and Sm-Nd isotopic systematics of mineral separates from the Ca-rich ureilite MET 78008 are reported. Extensive acid leaching procedures were used to eliminate terrestrial contamination because the amounts of U, Th, Pb, Sm, and Nd are extremely low in the meteorite. The three residues without terrestrial Pb contamination yield a Pb-Pb age of 4.563 +/- 0.021 Ga. On a U-Pb concordia diagram, the residue data corrected for an initial lead isotopic composition calculated with mu = 11.7 for 3 Ma from starting Canon Diablo troilite Pb in indicate a Pb-207*/Pb-206* model age of 4.563 Ga. The Sm-Nd isotopic data are scattered around the 4.56-Ga chondritic isochron. However, the Sm-Nd model age for handpicked augite is 4.573 +/- 0.029 Ga, assuming an initial CHUR composition. Two separates show a positive Nd-142 anomaly similar to those found in other meteorites of the same age (4.5-4.6 Ga). These Sm-Nd isotopic results support the Pb-Pb and U-Pb ages of this meteorite. Therefore, it is very likely that the formation age of ureilites is consistent with the so-called ''4.56-Ga canonical age of meteorites.'' It is also possible that extensive igneous processes for generating the ultramafic mineralogy of ureilites took place in the parent body within a few million years after formation of the solar nebula. C1 US GEOL SURVEY,DENVER,CO 80225. NATL INST POLAR RES,ITABASHI KU,TOKYO 173,JAPAN. RI Kita, Noriko/H-8035-2016 OI Kita, Noriko/0000-0002-0204-0765 NR 39 TC 19 Z9 19 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1995 VL 59 IS 11 BP 2319 EP 2329 DI 10.1016/0016-7037(95)00108-C PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RE522 UT WOS:A1995RE52200013 ER PT J AU MORGAN, JW HORAN, MF WALKER, RJ GROSSMAN, JN AF MORGAN, JW HORAN, MF WALKER, RJ GROSSMAN, JN TI RHENIUM-OSMIUM CONCENTRATION AND ISOTOPE SYSTEMATICS IN GROUP IIAB IRON-METEORITES SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID GROUP-IIIAB; MASS-SPECTROMETRY; TRACE-ELEMENT; CRYSTALLIZATION; FRACTIONATION; RU; CU; RE; OS AB Rhenium and osmium abundances, and osmium isotopic compositions were measured by negative thermal ionization mass spectrometry in thirty samples, including replicates, of five IIA and eight IIB iron meteorites. Concentrations in IIA irons range from 4800 ppb Re and 66000 ppb Os (Negrillos) to 160 ppb Re and 800 ppb Os (Lombard). In the IIB subgroup, concentrations vary from 28 ppb Re and 180 ppb Os (Navajo) down to 0.8 ppb Re and 9 ppb Os (Sao Juliao de Moreira and Santa Luzia). Log plots of Os vs. Re abundances for IIA and IIB irons describe straight lines that approximately converge on Lombard, which has the lowest Re and Os abundances and highest Re-187/Os-188 measured in a IIA iron to date. The linear IIA trend may be exactly reproduced by fractional crystallization with constant k(Re) and k(Os) but is not well fitted using variable partition coefficients. The IIB iron trend, however, cannot be entirely explained by simple fractional crystallization. One explanation is that small amounts of Re and Os were added to the asteroid core during the final stages of crystallization. Another possibility is that diffusional enrichment of Os may have occurred in samples most depleted in Re and Os. The combined Re-Os isotopic data for IIA irons give the following results: slope = 0.07803 +/- 0.00076; intercept = 0.09609 +/- 0.00045; age = 4584 +/- 43 Ma (neglecting the uncertainty in the decay constant of +/-3%). Four IIB iron meteorites (Mount Joy, Central Missouri, DRPA 78009, Santa Luzia) also plot within the analytical uncertainty of the IIA isochron. These results are consistent with rapid (probably <50 Ma) core segregation, differentiation, and crystallization in the IIAB parent. Several IIB irons (Navajo, Sandia Mountains, Smithsonian Iron, and perhaps Sao Juliao de Moreira) he beyond analytical uncertainty above the IIA iron isochron, averaging 8 +/- 2 parts per thousand higher in Os-187/Os-188. These irons may have crystallized significantly after the IIA irons and Mount Joy, but only if the Re-187/Os-188 Of the melt was greater than or equal to 2.2. There is no evidence for a IIA iron crystallizing in equilibrium with a melt having such a high ratio. Alternatively, the osmium isotopic systematics of these irons may have been slightly disturbed long after crystallization at ca. 3.3 Ga ago. C1 UNIV MARYLAND,DEPT GEOL,ISOTOPE GEOCHEM LAB,COLLEGE PK,MD 20742. RP MORGAN, JW (reprint author), US GEOL SURVEY,MAIL STOP 981,RESTON,VA 22092, USA. RI Walker, Richard/K-6869-2016 OI Walker, Richard/0000-0003-0348-2407 NR 41 TC 88 Z9 94 U1 2 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1995 VL 59 IS 11 BP 2331 EP 2344 DI 10.1016/0016-7037(95)00109-D PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RE522 UT WOS:A1995RE52200014 ER PT J AU YOU, CF SPIVACK, AJ GIESKES, JM ROSENBAUER, R BISCHOFF, JL AF YOU, CF SPIVACK, AJ GIESKES, JM ROSENBAUER, R BISCHOFF, JL TI EXPERIMENTAL-STUDY OF BORON GEOCHEMISTRY - IMPLICATIONS FOR FLUID PROCESSES IN SUBDUCTION ZONES SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID BARBADOS ACCRETIONARY COMPLEX; ORGANIC-RICH SEDIMENT; B-BE SYSTEMATICS; ISOTOPIC FRACTIONATION; HYDROTHERMAL SYSTEM; MARINE-SEDIMENTS; SEA-WATER; 500 BARS; SEAWATER; CONSTRAINTS AB A comprehensive experimental study, utilizing an autoclave hydrothermal apparatus with a B-10 isotopic tracer, has been conducted to monitor the geochemical behavior of sediment B during early subduction zone processes. The partition coefficient of exchangeable B (K-D) was determined over a temperature range of 25-350 degrees C, at 800 bars and a water/rock ratio of 3-1.5 w/w. These K-D are shown to be a complex function of temperature, pH, and possibly mineralogy. At low temperatures, K-D is significantly high at similar to 4 in contrast to the value of essentially zero at temperatures higher than similar to 100 degrees C. A K-D of zero represents no B adsorption, implying efficient mobilization of exchangeable B at shallow depths during sediment subduction. Our experimental results demonstrate high mobilization of bulk B in sediments (both exchangeable and lattice bound) at elevated temperatures (200-350 degrees C), in good agreement with previous observations of B in metasediments indicating progressive depletion during metamorphism. In addition, this study emphasizes the importance of a possible water/rock ratio dependence of B mobilization. In other words, the degree of sedimentary B mobilization in subduction zones strongly depends on the local thermal structure and porosity distribution. In low geothermal gradient areas, large amounts of porewater are expelled before significant B mobilization has occurred, so that some sedimentary B will survive and get into the deeper parts of the subduction zone. Our results imply that efficient mobilization of B from the subducted slab must occur and that are magmatism recycles most of the remaining subducted B back to surface reservoirs. A reconsideration of the B budget in subduction zones provides critical information with respect to B sources and sinks in the ocean. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP YOU, CF (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 57 TC 77 Z9 79 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1995 VL 59 IS 12 BP 2435 EP 2442 DI 10.1016/0016-7037(95)00137-9 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF202 UT WOS:A1995RF20200003 ER PT J AU TORIGOYEKITA, N MISAWA, K DALRYMPLE, GB TATSUMOTO, M AF TORIGOYEKITA, N MISAWA, K DALRYMPLE, GB TATSUMOTO, M TI FURTHER EVIDENCE FOR A LOW U/PB, SOURCE IN THE MOON - U-TH-PB, SM-ND, AND AR-AR ISOTOPIC SYSTEMATICS OF LUNAR METEORITE YAMATO-793169 SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EVOLUTION; LEAD; AGE AB The coarse-grained lunar meteorites, Yamato-793169 and Asuka-881757, represent a new type of low-Ti mare basalt. This paper reports the results of a U-Th-Pb, Sm-Nd, and Ar-Ar isotopic study of Yamato-793169 performed as part of a consortium studies of lunar basaltic meteorites. The isotopic study was carried out on a small sample (100 mg) so that only three density fractions could be separated. These fractions were leached with dilute acid in order to eliminate terrestrial Pb contamination. However, the leaching procedure did not completely remove this contamination in some fractions and also apparently caused a fractionation of elements (U, Th, Pb) due to preferential leaching effects, producing a secondary disturbance of the systematics. Furthermore, the Ar-Ar analyses indicate that the isotopic systematics in this meteorite might have been disturbed sometime later than 750 Ma. For these reasons, the ages obtained using different isotopic systems disagree with each other and a precise formation age could not be obtained for this meteorite. However, using what results there are, two reasonable interpretations can be made: (1) the Sm-Nd system yielded an age of 3.4 Ga that could be interpreted as the formation age, assuming that this system is possibly the least disturbed during the metamorphic event(s) that this meteorite experienced at least once, and that all other isotopic systems and their corresponding ages were disturbed, and (2) the U-Pb system yielded a nearly concordant age of 3.8 Ga that could be interpreted as the formation age and the Sm-Nd isotopic systematics were somehow disturbed. We prefer the second interpretation for the reasons discussed below. On a concordia diagram, the CDT (Canon Diablo troilite)-corrected U-Pb isotopic data yield a discordia line similar to the lunar catastrophic array, indicating that the source of the meteorite formed during early lunar differentiation (similar to 4.4 Ga) and that the basalt was generated near 3.9 Ga. Total Ar-Ar age on plagioclase is 3.26 Ga, which seems to be too old if the formation age is 3.4 Ga, because low temperature fractions lost large amounts of radiogenic Ar-40 during the late thermal event. If we assume a formation age of 3.8 Ga, the estimated source U-238/Pb-204 (mu) is 21.6 +/- 3.5 and epsilon(Nd) is 3.9 +/- 0.3. These results indicate that the source of Yamato-793169 is more depleted than Apollo 12 and 15 LT basalts, but less depleted than Asuka-881757. Therefore, Yamato-793169 may represent a new type of LT- or VLT-like mare basalt that is different from Asuka-881757. The wide variety of lead and neodymium isotopic characteristics among LT and VLT mare basalts indicate that the lunar mantle was very heterogeneous with respect to trace element abundances. C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. RP TORIGOYEKITA, N (reprint author), GEOL SURVEY JAPAN,1-1-3 HIGASHI,TSUKUBA,IBARAKI 305,JAPAN. RI Kita, Noriko/H-8035-2016 OI Kita, Noriko/0000-0002-0204-0765 NR 49 TC 16 Z9 17 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1995 VL 59 IS 12 BP 2621 EP 2632 DI 10.1016/0016-7037(95)00154-9 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF202 UT WOS:A1995RF20200020 ER PT J AU DALLIMORE, SR COLLETT, TS AF DALLIMORE, SR COLLETT, TS TI INTRAPERMAFROST GAS HYDRATES FROM A DEEP CORE-HOLE IN THE MACKENZIE DELTA, NORTHWEST-TERRITORIES, CANADA SO GEOLOGY LA English DT Article AB Visible gas hydrate and possible pore-space hydrate samples have been recovered for the first time in North America from within ice-bonded permafrost in a 451-m-deep core hole in the Mackenzie Delta, Northwest Territories, Canada. The visible hydrate was found as thin icelike Layers that released methane gas initially upon retrieval, but stabilized for up to 4 h at atmospheric pressure conditions and subfreezing temperatures, The temporary stabilization of hydrate samples is attributed to the self-preservation phenomenon described by others on the basis of laboratory studies. High methane concentrations in well-ice-bonded sediments and gas releases suggest that pore-space hydrate may be found at depths as shallow as 119 m. Geochemical and isotopic determinations suggest that the methane hydrate observed in the core hole is biogenic (microbial) in origin. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP DALLIMORE, SR (reprint author), GEOL SURVEY CANADA,601 BOOTH ST,OTTAWA,ON K1A 0E8,CANADA. NR 16 TC 44 Z9 62 U1 1 U2 11 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUN PY 1995 VL 23 IS 6 BP 527 EP 530 DI 10.1130/0091-7613(1995)023<0527:IGHFAD>2.3.CO;2 PG 4 WC Geology SC Geology GA RB222 UT WOS:A1995RB22200012 ER PT J AU OTTON, JK AF OTTON, JK TI WESTERN FRONTAL FAULT OF THE CANYON RANGE - IS IT THE BREAKAWAY ZONE OF THE SEVIER DESERT DETACHMENT SO GEOLOGY LA English DT Article ID SEISMIC-REFLECTION DATA; CENOZOIC EXTENSION; EASTERN BASIN; UTAH AB Geologic evidence developed from surface exposures demonstrates that the western frontal fault of the Canyon Range is a major structure representing the eastern breakaway zone of the Sevier Desert detachment, The western frontal fault of the Canyon Range east of Delta, Utah, is a north-trending, west-dipping, low-angle (18 degrees-24 degrees) normal fault that juxtaposes syntectonic conglomerates and large-rock avalanches of the Miocene Oak City Formation against footwall rocks that have been ductilely, cataclastically, and brittlely deformed. The Oak City strata dip variably to the east; dips are shallow in eastern outcrops (5 degrees-15 degrees), steeper in central outcrops (20 degrees-60 degrees), and shallow in the western outcrops (10 degrees-20 degrees), In eastern exposures, the shallow dips of the Oak City Formation (5 degrees-15 degrees) and the acute angle of 20 degrees-35 degrees between the western frontal fault and Oak City units limit past rotation of the fault to less than or equal to 15 degrees. The systematic variation in the dip of Oak City units from east to west suggests that the western frontal fault probably flattens beneath present Oak City outcrops, linking the fault to the shallow reflector seen in the COCORP (Consortium for Continental Reflection Profiting) Utah line 1 seismic line beneath the westernmost outcrops of the Oak City Formation, Upper plate movement is constrained by Oak City clast compositions and rock-avalanche lithologies, fault geometry, and lower plate reconstruction to a maximum of 6-7 km since Oak City syntectonic deposition at similar to 12-13 Ma. Maximum upper plate displacement for the entire Sevier Desert detachment cannot be determined from these breakaway-zone exposures. RP OTTON, JK (reprint author), US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225, USA. NR 22 TC 16 Z9 16 U1 0 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUN PY 1995 VL 23 IS 6 BP 547 EP 550 DI 10.1130/0091-7613(1995)023<0547:WFFOTC>2.3.CO;2 PG 4 WC Geology SC Geology GA RB222 UT WOS:A1995RB22200017 ER PT J AU MENDOZA, C AF MENDOZA, C TI FINITE-FAULT ANALYSIS OF THE 1979 MARCH 14 PETATLAN, MEXICO, EARTHQUAKE USING TELESEISMIC P-WAVE-FORMS SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE EARTHQUAKES; FAULT SLIP; MEXICO; P WAVES ID 1986 ANDREANOF ISLANDS; SLIP DISTRIBUTION; RUPTURE HISTORY; COSEISMIC SLIP; BENIOFF ZONE; INVERSION; MICHOACAN; SEISMICITY; CALIFORNIA; PATTERNS AB Vertical, teleseismic P waves recorded for the 1979 March 14 Petatlan, Mexico, earthquake were used to derive the distribution of coseismic slip using a linear finite-fault inversion scheme that solves for the amount of slip in each of a series of consecutive time windows. Data recorded by six stations of the Global Digital Seismograph Network were inverted in addition to digitized analogue long-period recordings available from nine Worldwide Standardized Seismograph Network stations. The digital data include four broad-band and short-period velocity waveforms reconstructed from the short- and long-period components. The time-window approach allows for a variable rise time on the fault and accounts for the source multiplicity evident in the recorded P waveforms. Synthetic tests conducted using the inversion method on the limited data set, however, reveal that the data are insufficient to identify the exact dislocation duration on the fault. The method is thus implemented by prescribing the fault rise time using five consecutive 1 s time windows. The coseismic slip inferred from the P waves shows a small 70 cm peak near the earthquake hypocentre and a large zone of dislocation (1.2 m maximum) further south-east. The slip pattern covers depths from 3 to 25 km and is located south-east of other recent large interplate ruptures on the Michoacan segment of the Mexican subduction zone. This result indicates that the 1979 Petatlan earthquake broke an independent, adjacent portion of the Cocos-North America plate boundary. The seismic moment of 1.5 x 10(27) dyn cm inferred from the P waves is approximately one-half the long-period moment estimated by other investigators from the observed surface waves. Although the discrepancy is within the uncertainty of the seismic-moment estimates, it may suggest the presence of a component of slow interplate motion that did not radiate significant P-wave energy. RP MENDOZA, C (reprint author), US GEOL SURVEY,NATL EARTHQUAKE INFORMAT CTR,DENVER FED CTR,BOX 25046,MS 967,LAKEWOOD,CO 80225, USA. NR 28 TC 24 Z9 25 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUN PY 1995 VL 121 IS 3 BP 675 EP 683 DI 10.1111/j.1365-246X.1995.tb06430.x PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RB176 UT WOS:A1995RB17600003 ER PT J AU SOLLER, DR BERG, TM AF SOLLER, DR BERG, TM TI DEVELOPING NATIONAL GEOLOGIC MAP DATABASE SO GEOTIMES LA English DT Article RP SOLLER, DR (reprint author), USGS,908 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD JUN PY 1995 VL 40 IS 6 BP 16 EP 18 PG 3 WC Geosciences, Multidisciplinary SC Geology GA RB688 UT WOS:A1995RB68800007 ER PT J AU MCCABE, GJ HAY, LE AF MCCABE, GJ HAY, LE TI HYDROLOGICAL EFFECTS OF HYPOTHETICAL CLIMATE-CHANGE IN THE EAST-RIVER BASIN, COLORADO, USA SO HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES LA English DT Article AB In 1988, the US Geological Survey began a study of the effects of potential climate change on the water resources of the Gunnison River basin. The Gunnison River, in southwestern Colorado, is an important tributary of the Colorado River, contributing approximately 40% of the flow of the Colorado River at the Colorado/Utah stateline. As part of the study, the sensitivity of annual and seasonal runoff in the East River basin, a sub-basin of the Gunnison River basin, to changes in temperature and precipitation was examined. To perform the sensitivity analyses, hypothetical climate changes were used to alter current time series of temperature and precipitation. The altered time series were then used as inputs to a hydrological model that translated these inputs into estimates of runoff. Mean annual and seasonal runoff resulting from a range-of-hypothetical climate changes were compared and evaluated. Results indicated that in general, changes in precipitation had a larger effect on changes in runoff than did changes in temperature. Changes in precipitation had significant effects on runoff during all seasons. Changes in temperature primarily affected the temporal distribution of runoff through the year. Changes in temperature affected the timing of snowmelt and the ratio of rain to snow, and therefore the effects of temperature were particularly significant during the spring and summer seasons. On an annual basis, increases in temperature led only to slight decreases in runoff. Results also indicated that the effects of an increase in mean annual temperature of 4 degrees C on annual runoff could be offset by an increase in annual precipitation of between 4 and 5%, and that the magnitude of natural climatic variability was large and might mask the effects of long term climate changes. RP MCCABE, GJ (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 412,LAKEWOOD,CO 80225, USA. NR 0 TC 24 Z9 24 U1 0 U2 3 PU IAHS PRESS, INST HYDROLOGY PI WALLINGFORD PA C/O SARAH CAGE, WALLINGFORD, ENGLAND OX10 8BB SN 0262-6667 J9 HYDROLOG SCI J JI Hydrol. Sci. J.-J. Sci. Hydrol. PD JUN PY 1995 VL 40 IS 3 BP 303 EP 318 DI 10.1080/02626669509491417 PG 16 WC Water Resources SC Water Resources GA RA579 UT WOS:A1995RA57900002 ER PT J AU HOGENBOOM, DL KARGEL, JS GANASAN, JP LEE, L AF HOGENBOOM, DL KARGEL, JS GANASAN, JP LEE, L TI MAGNESIUM SULFATE-WATER TO 400 MPA USING A NOVEL PIEZOMETER - DENSITIES, PHASE-EQUILIBRIA, AND PLANETOLOGICAL IMPLICATIONS SO ICARUS LA English DT Article ID REFLECTANCE SPECTRA; ICY SATELLITES; VOLCANISM; CHONDRITES; ASTEROIDS AB Carbonaceous chondrites commonly contain 10-20% water-soluble salts by mass, the products of low-temperature aqueous alteration under oxidizing conditions. About 75% (by mass) of chondrite salts typically consists of magnesium sulfate hydrates, Conditions similar to those that affected carbonaceous chondrites may have prevailed within some asteroids and icy satellites, resulting in the formation of similar salt-rich rock (plus ice). These salts would be important in determining the physical and chemical characteristics of cryomagmatic brines. Frozen eutectic mixtures of MgSO4-rich brines could constitute a large fraction of the mass and volume of differentiated salty icy satellites, and widespread volcanic ice plains on some icy satellites may consist of frozen MgSO4-rich brines, The nature of brine magmatism depends in part on phase equilibria and volumetric relations of solid and liquid phases under the pertinent conditions of temperature, pressure, and other physical parameters. Accordingly, we have investigated densities and phase equilibria in the system MgSO4-H2O under pressures ranging from similar to 0.1 MPa to similar to 400 MPa, temperatures from 230 K to 300 K, and compositions up to 22% (by mass) MgSO4 using a novel high-pressure apparatus, described here for the first time in detail. We have found no evidence for a transition of MgSO4 hydrates to high-pressure polymorphs, although we have seen the expected transitions in water ice and we have found some evidence of a possible new magnesium sulfate hydrate, The graph of the eutectic melting point vs pressure approximately parallels the melting curve of water ice, except that the freezing-point depression increases slightly with pressure. Brine flows on icy satellites and chondritic asteroids mostly should correspond to eutectic and peritectic compositions (similar to 17 and similar to 21% MgSO4, respectively, if modeled in the pure system H2O-MgSO4; compositions vary somewhat with pressure). Ice phases I and III, MgSO4 hydrates, and the eutectic solid mixture have large density differentials with respect to the eutectic liquid. Because of this and the liquid's low viscosity, gravitational separation of solids and liquids (fractional melting and fractional crystallization) could be very efficient even on low-g satellites and asteroids, Flotation of water ice may cause a tendency of brine flows to have salt-depleted, ice-rich surfaces. Brine intrusions should tend to segregate into ice-rich and salt-rich layers. Ice-rich masses in layered intrusions would be highly buoyant in a salt-ice crust and may be prone to solid-state diapirism. Ice diapirism offers an alternative explanation for palimpsests observed on Ganymede and viscous flows seen on Ganymede, Ariel, and Miranda. Large-scale brine magmatism may cause global compositional stratification of crusts and mantles, The ice crusts on some salty icy satellites may have formed in part by flotation of ice grains in brine magma bodies and coalescence of intrusive complexes of ice. The mantles of large salty icy satellites may consist of hydrated and anhydrous salts and high-pressure ice phases formed by sinking of these minerals. These processes have analogs in the formation of the lunar anorthositic highlands crust and mantle. (C) 1995 Academic Press, Inc. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. UNIV N CAROLINA,DEPT ELECT ENGN,CHARLOTTE,NC 28223. RP HOGENBOOM, DL (reprint author), LAFAYETTE COLL,DEPT PHYS,EASTON,PA 18042, USA. NR 52 TC 74 Z9 74 U1 0 U2 15 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD JUN PY 1995 VL 115 IS 2 BP 258 EP 277 DI 10.1006/icar.1995.1096 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA RD555 UT WOS:A1995RD55500004 ER PT J AU MCCABE, GJ DETTINGER, MD AF MCCABE, GJ DETTINGER, MD TI RELATIONS BETWEEN WINTER PRECIPITATION AND ATMOSPHERIC CIRCULATION SIMULATED BY THE GEOPHYSICAL FLUID-DYNAMICS LABORATORY GENERAL-CIRCULATION MODEL SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE GFDL, GCM; US WINTER PRECIPITATION; 700 HPA CIRCULATION ID MONTHLY MEAN CIRCULATION; UNITED-STATES; HEIGHT FIELD; CLIMATE; SPECIFICATION; TEMPERATURE; SENSITIVITY AB General circulation model (GCM) simulations of atmospheric circulation are more reliable than GCM simulations of temperature and precipitation. Thus, some researchers are developing empirical relations between observed atmospheric circulation and observed temperature and precipitation to translate GCM estimates of future atmospheric circulation into estimates of future regional temperature and precipitation. Developing climate-change scenarios in this manner assumes, at least, that relationships between atmospheric circulation and surface climate variables, such as temperature and precipitation, are properly simulated by GCMs. In this study, temporal correlations between 700 hPa height anomalies (700 hPa anomalies) over North America simulated by the Geophysical Fluid Dynamics Laboratory (GFDL) GCM and GFDL-GCM-simulated (GFDL-simulated) winter precipitation at eight locations in the conterminous United States are compared with corresponding correlations in observations. The objectives are to (i) characterize the relations between atmospheric circulation and winter precipitation simulated by the GFDL GCM for selected locations in the conterminous USA, (ii) determine whether these relations are similar to those found in observations of the actual climate system, and (iii) determine if GFDL-simulated precipitation is forced by the same circulation patterns as in the real atmosphere. Results indicate that the GFDL GCM simulates relations between 700 hPa anomalies and local winter precipitation that are similar to relations found in observed data for most of the locations analysed in this study. Results also indicate that at regional scales GFDL GCM simulations of the relations between 700 hPa anomalies and winter precipitation are most similar to observed relations for locations near oceanic sources of atmospheric moisture. These results suggest that the GFDL GCM may not adequately simulate variations in advection of atmospheric moisture into the interior parts of the USA and!or that this moisture is not adequately converted into precipitation in the interior parts of the country. This problem may be due, in part, to (i) the inadequate representation of topography in the GFDL GCM, (ii) stronger-than-observed mean winter zonal winds simulated by the GFDL GCM and the consequent more west-to-east paths of air flow and storm systems across North America, (iii) the relative weakness of important synoptic patterns in CFDL simulations, such as the Pacific North American circulation pattern, and (iv) the occurrence of 'spectral rain'. In addition, for some locations, the GFDL-simulated relationships between precipitation and 700 hPa anomalies can be quite different from observed relations. The differing relationships suggest that GFDL-simulated changes in xregional precipitation in response to changes in atmospheric circulation could differ from changes that would occur in the actual climate system. C1 US GEOL SURVEY, SAN DIEGO, CA 92123 USA. RP MCCABE, GJ (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 412, DENVER, CO 80225 USA. NR 39 TC 4 Z9 4 U1 1 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0899-8418 EI 1097-0088 J9 INT J CLIMATOL JI Int. J. Climatol. PD JUN PY 1995 VL 15 IS 6 BP 625 EP 638 DI 10.1002/joc.3370150604 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA RG761 UT WOS:A1995RG76100003 ER PT J AU YOUNG, DD MCINTYRE, CL BENTE, PJ MCCABE, TR AMBROSE, RE AF YOUNG, DD MCINTYRE, CL BENTE, PJ MCCABE, TR AMBROSE, RE TI NESTING BY GOLDEN EAGLES ON THE NORTH SLOPE OF THE BROOKS RANGE IN NORTHEASTERN ALASKA SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article AB Twenty-two Golden Eagle (Aquila chrysaetos) nesting territories and 31 occupied eagle nests were documented on the north slope of the Brooks Range in northeastern Alaska, 1988-1990, in an area previously thought to be marginal breeding habitat for eagles. The mean number of young/successful nest was 1.25 in 1988, 1.27 in 1989, and 1.13 in 1990; means did not differ significantly among years. Eighty percent (20/25) of the nestlings for which age was estimated were assumed to have successfully fledged. Nesting success was 79% (11/14) in 1989, the only year nesting success could be determined. Laying dates ranged from 23 March (1990) to 11 May (1989) with mean estimated laying dates differing significantly among years. Annual variation in nesting phenology coincided with annual differences in snow accumulations during spring. These results indicate that Golden Eagles consistently and successfully breed at the northern extent of their range in Alaska, although, productivity may be lower than that for eagles at more southern latitudes. C1 NATL PK SERV,ALASKA REG OFF,ANCHORAGE,AK 99503. US FISH & WILDLIFE SERV,FAIRBANKS,AK 99701. RP YOUNG, DD (reprint author), US NATL BIOL SERV,ALASKA SCI CTR,FAIRBANKS FIELD STN,101 12TH AVE,BOX 15,FAIRBANKS,AK 99701, USA. NR 18 TC 4 Z9 4 U1 1 U2 5 PU ASSOC FIELD ORNITHOLOGISTS PI BELOIT PA BELOIT COLLEGE, DEPT BIOLOGY, 700 COLLEGE ST, BELOIT, WI 53511 SN 0273-8570 J9 J FIELD ORNITHOL JI J. Field Ornithol. PD SUM PY 1995 VL 66 IS 3 BP 373 EP 379 PG 7 WC Ornithology SC Zoology GA RL134 UT WOS:A1995RL13400007 ER PT J AU LING, CH AF LING, CH TI CRITERIA FOR INCIPIENT MOTION OF SPHERICAL SEDIMENT PARTICLES SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID BED AB Initiation of bed-load transport of uniform spherical sediment particles on a horizontal bed in an open-channel flow is studied. On the basis of micromechanical and fluid dynamical considerations, two separate criteria for the initiation of motion are derived: one for rolling and one for lifting. Fluid forces such as drag, shear lift, Magnus lift, and lift due to centrifugal force are included in the derivation. The formulation of the lift force is theoretical. No empirical coefficient is used other than the drag coefficient C-d, which is well established in the literature. In the low particle Reynolds number regime, where u*d/nu less than or equal to 1, the dimensionless stress required to initiate lifting is found to be much higher than that of rolling, the former substantially above the Shields' curve while the latter is substantially below it. The theory is compared with Vanoni's 1964 data, with meaningful results. For higher particle Reynolds number, where u*d/nu > 10, the dimensionless stress needed to initiate lifting is closer to that of rolling. The Shields' curve for the most part lies between the two theoretical thresholds. RP LING, CH (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,345 MIDDLEFIELD RD,MS-496,MENLO PK,CA 94025, USA. NR 26 TC 48 Z9 48 U1 1 U2 7 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD JUN PY 1995 VL 121 IS 6 BP 472 EP 478 DI 10.1061/(ASCE)0733-9429(1995)121:6(472) PG 7 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA QY859 UT WOS:A1995QY85900004 ER PT J AU PLUMPTON, DL DOWNING, DI ANDERSEN, DE LOCKHART, JM AF PLUMPTON, DL DOWNING, DI ANDERSEN, DE LOCKHART, JM TI A NEW METHOD OF CAPTURING BUTEONINE HAWKS SO JOURNAL OF RAPTOR RESEARCH LA English DT Note DE BUTEO JAMAICENSIS; BUTEO REGALIS; BUTEO SWAINSONI; FERRUGINOUS HAWK; RED-TAILED HAWK; ROAD TRAPPING; SWAINSONS HAWK C1 US FISH & WILDLIFE SERV,ROCKY MT ARSENAL NATL WILDLIFE AREA,COMMERCE CITY,CO 80022. US FISH & WILDLIFE SERV,ANCHORAGE,AK 99503. UNIV MINNESOTA,DEPT FISHERIES & WILDLIFE,US NATL BIOL SERV,ST PAUL,MN 55108. RP PLUMPTON, DL (reprint author), UNIV MINNESOTA,DEPT FISHERIES & WILDLIFE,MINNESOTA COOPERAT FISH & WILDLIFE RES UNIT,ST PAUL,MN 55108, USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD JUN PY 1995 VL 29 IS 2 BP 141 EP 143 PG 3 WC Ornithology SC Zoology GA RG919 UT WOS:A1995RG91900011 ER PT J AU LIDZ, BH MCNEILL, DF AF LIDZ, BH MCNEILL, DF TI DEEP-SEA BIOSTRATIGRAPHY OF PROGRADING PLATFORM MARGINS (NEOGENE, BAHAMAS) - KEY EVIDENCE LINKED TO DEPOSITIONAL RHYTHM SO MARINE MICROPALEONTOLOGY LA English DT Article ID RIO-GRANDE RISE; PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY; SOUTH-ATLANTIC; PLIOCENE; BOUNDARY AB New foraminiferal evidence from two boreholes on the paleoshelf and slope of western Great Bahama Bank has wide-ranging implications for understanding formation and evolution of carbonate-platform margins. The new data, abundant well-preserved planktic foraminifera, were obtained by disaggregating samples from intercalated pelagic layers and selected parts of thick hemipelagic limestone. Earlier efforts to obtain biostratigraphic ages identified six biostratigraphic units in each borehole, provided biozonal age alternatives for both holes, and resulted in different Pliocene biozones between them. The new data define six units in one hole and seven in the other, bracket the biozones present and their ages, indicate different sedimentation rates, and show that within the limits of biostratigraphic resolution the biozones are correlative between the holes. Most importantly, the revised ages show that the paleoshelf borehole probably penetrated the late Miocene rather than middle Miocene. The oldest unit is on the paleoshelf and the youngest (uppermost Pliocene) is on the slope. Between the holes, the stratigraphic interval spans the temporal interval from an inferred maximum of similar to 10.2 Ma to a minimum of similar to 1.6 Ma. Although the biozones range sequentially from the Neogloboquadrina acostaensis (N16) Zone to the basal part of the Globorotalia truncatulinoides truncatulinoides (N22) Zone (Globorotalia crassaformis viola Subzone), absence of key species indicates that deposition was discontinuous. Numerous periods of erosion and/or nondeposition are inferred, the largest of which is a condensed section/ hiatus (similar to 1.2 Myr) above the paleoslope Miocene/Pliocene boundary. In addition, the late Pliocene Globorotalia tosaensis tosaensis (N21) Zone is not recognized on the slope. Its absence is consistent with a widespread regional unconformity. Sedimentation rates and depths of series boundaries vary widely in both holes. The paleoslope Miocene/Pliocene boundary lies at similar to 540 m below top of the hole. The lower/upper Pliocene boundary is placed at or near 444 m. Position of the Pliocene/ Pleistocene boundary is less certain but is within the top 382 m of the hole. Its placement anywhere within this interval is a reasonable assessment considering an exceptionally high rate of sedimentation ( similar to 562 m/Myr; 168.6 m interval, based on topmost foraminiferal sample; 1.9-1.6 Ma). As expected, the lowest sedimentation rate occurs in the condensed section overlying the Miocene/Pliocene boundary ( similar to 5 m/Myr, 9.5 m, 5.3-4.1 Ma). The paleoshelf Miocene/Pliocene boundary lies below a hiatal condensed section (295-278 m below top of the hole) that has a greater sedimentation rate ( similar to 89 m/Myr, 17.7 m, 5.5-5.3 Ma) than that at the slope. The lower/upper Pliocene boundary is placed at or near a depth of 236 m, and the Pliocene/Pleistocene boundary lies within the top 113 m of the hole. Sedimentation rates on the shelf range from similar to 15 m/Myr above the condensed section (22.9 m, 5.3-3.8 Ma) to a late Pliocene high of similar to 183 m/Myr (54.9 m interval, based on the point at which the age-depth line crosses the 1.9 Myr mark between the topmost two fossiliferous samples; 2.2-1.9 Ma). C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. RP LIDZ, BH (reprint author), US GEOL SURVEY,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 33 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD JUN PY 1995 VL 25 IS 2-3 BP 87 EP 125 DI 10.1016/0377-8398(95)00021-R PG 39 WC Paleontology SC Paleontology GA RF801 UT WOS:A1995RF80100001 ER PT J AU STRAHLE, W AF STRAHLE, W TI THE LOST INSTRUMENT NETWORK SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article RP STRAHLE, W (reprint author), US GEOL SURVEY,ATLANT MARINE GEOL BRANCH,WOODS HOLE,MA 02543, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA 1828 L ST NW 9TH FLOOR, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SUM PY 1995 VL 29 IS 2 BP 67 EP 68 PG 2 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA RR994 UT WOS:A1995RR99400008 ER PT J AU KOOPMANS, MP DAMSTE, JSS LEWAN, MD DELEEUW, JW AF KOOPMANS, MP DAMSTE, JSS LEWAN, MD DELEEUW, JW TI THERMAL-STABILITY OF THIOPHENE BIOMARKERS AS STUDIED BY HYDROUS PYROLYSIS SO ORGANIC GEOCHEMISTRY LA English DT Article DE ALKYLTHIOPHENES; ORGANIC SULFUR COMPOUNDS; BIOMARKERS; ARTIFICIAL MATURATION; HYDROUS PYROLYSIS; DIAGENESIS ID ORGANICALLY-BOUND SULFUR; GEOCHEMICAL SIGNIFICANCE; MOLECULAR STRATIGRAPHY; SEA SEDIMENTS; IDENTIFICATION; HYDROCARBONS; DIAGENESIS; MATURATION; C-30 AB An immature (R(o) = 0.25%) sulphur-rich calcareous shale from the Gessoso-solfifera Formation (Messinian) in the Vena del Gesso Basin (northern Italy) was artificially matured hyhydrous pyrolysis at constant temperatures ranging from 160 to 330 degrees C for 72 h to study the applicability of alkylthiophenes as molecular indicators during progressive diagenesis and early catagenesis. Artificial maturation at temperatures up to 330 degrees C generated large amounts of alkylthiophenes from thethermal degradation of kerogen. The importance of the kerogen in the production of alkylthiophenes is supported by the observation that the isomer distributions of alkylthiophenes at high temperatures coincide with the isomer distributions of alkylthiophenes in the Curie-point pyrolysate of the isolated kerogen of the original sample. The generation profiles of the thiophenes with a phytane carbon skeleton and the 3,4-di-n-alkylthiophenes suggest that continuous degradation of alkylthiophenes is also taking place, so that the overall effect is alkylthiophene concentrations with intermediate values. The structural isomer distribution of linear alkylthiophenes does not change significantly when these compounds are generated at different temperatures; This implies that important information regarding the original positions of functionalities in the precursor molecules is retained and, thus, that alkylthiophenes are useful biomarkers at relatively high levels of thermal maturity (up to R(o) approximate to 0.95-1.1%). C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP KOOPMANS, MP (reprint author), NETHERLANDS INST SEA RES,DEPT MARINE BIOGEOCHEM,POB 59,1790 AB DEN BURG,NETHERLANDS. RI de Leeuw, Jan/F-6471-2011; Sinninghe Damste, Jaap/F-6128-2011 OI Sinninghe Damste, Jaap/0000-0002-8683-1854 NR 37 TC 41 Z9 41 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD JUN PY 1995 VL 23 IS 6 BP 583 EP 596 DI 10.1016/0146-6380(95)00039-H PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RV612 UT WOS:A1995RV61200008 ER PT J AU MCDOUGALL, K AF MCDOUGALL, K TI AGE OF THE FISHCREEKIAN TRANSGRESSION SO PALAIOS LA English DT Review ID ARCTIC NORTH-AMERICA; BENTHIC FORAMINIFERA; OXYGEN ISOTOPE; BAFFIN ISLAND; SEA; PALEOCEANOGRAPHY; ALASKA; OCEAN; ICE; STRATIGRAPHY AB The Fishcreekian transgression is one of a sequence of late Cenozoic marine transgressions recognized on the Alaskan Arctic Coastal Plain. The Fish Creek beds of northern Alaska, which were designated as the type section for this transgression (Carter and Galloway, 1985), contain fossils interpreted as Pliocene in age (2.48 Ma, Repenning et al., 1987; 2.41-2.14 Ma, Brigham-Grette and Carter, 1992). Analysis of the benthic foraminifers in the Fish Creek beds, however, indicates that deposition occurred in the latest Pliocene and early Pleistocene between 1.7 and 1.2 Ma during a ''warm'' interval which was characterized by climatic conditions similar to the present or slightly warmer where temperatures shifted within a relatively narrow range. The late Pliocene to early Pleistocene benthic foraminiferal fauna is distinctive and can be traced throughout the circum-Arctic region. This fauna is dominated by elphidiums and elphidiellids, particularly E. hannai, E. rolfi, and E. ustulatum. Paleomagnetics, geochemical analyses, and world-wide climatic conditions support the latest Pliocene and early Pleistocene age interpretation for these deposits. Examination of the basis for the older age interpretation and the age of the diagnostic vertebrate, ostracode, molluscan, spare, and pollen species shows that the latest Pliocene and early Pleistocene age for the transgression is well within the limitations imposed by these fossil groups. RP MCDOUGALL, K (reprint author), US GEOL SURVEY,MAIL STOP 915,MENLO PK,CA 94025, USA. NR 114 TC 7 Z9 7 U1 0 U2 2 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 0883-1351 J9 PALAIOS JI Palaios PD JUN PY 1995 VL 10 IS 3 BP 199 EP 220 DI 10.2307/3515253 PG 22 WC Geology; Paleontology SC Geology; Paleontology GA RF378 UT WOS:A1995RF37800002 ER PT J AU ROWAN, LC BOWERS, TL AF ROWAN, LC BOWERS, TL TI ANALYSIS OF LINEAR FEATURES MAPPED IN LANDSAT THEMATIC MAPPER AND SIDE-LOOKING AIRBORNE RADAR IMAGES OF THE RENO 1-DEGREES BY 2-DEGREES QUADRANGLE, NEVADA AND CALIFORNIA - IMPLICATIONS FOR MINERAL-RESOURCE STUDIES SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB Linear tonal features, which reflect topographic and lithologic differences, were mapped in Landsat Thematic Mapper (TM) and side-looking airborne radar (SLAR) images of the Reno 1 degrees by 2 degrees guadrangle, Nevada and California; combined into a single data set; and compared to the distribution of known Tertiary An-Ag vein mineralization. The results of analyses of orientation and areal density show that in most areas the linear features are expressions of geologic structures that controlled the mineralization. However, the variability of the spatial correspondence of the two linear features attributes with mines necessitated ranking orientation and areal density values for incorporation into a numerical mineral assessment model. The results show that the combined spatial resolution of the TM and SLAR images permits delineation of structures that controlled Tertiary precious-metal mineralization in this area. However, the tonal expression of some important structures may be below the resolution limit. Other factors that contribute to the variability of the results are the unknown age of linear features, illumination-induced biases, and shadowing in high-relief terrain. RP ROWAN, LC (reprint author), US GEOL SURVEY,MS 927 NATL CTR,RESTON,VA 22092, USA. NR 15 TC 13 Z9 13 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JUN PY 1995 VL 61 IS 6 BP 749 EP 759 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA RA867 UT WOS:A1995RA86700005 ER PT J AU MINOCHA, R SHORTLE, WC LAWRENCE, GB DAVIS, MB MINOCHA, SC AF MINOCHA, R SHORTLE, WC LAWRENCE, GB DAVIS, MB MINOCHA, SC TI POLYAMINES AS BIOCHEMICAL MARKER OF STRESS IN TREES SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 NEFFS,USDA FOREST SERV,DURHAM,NH 03824. US GEOL SURVEY,ALBANY,NY 12201. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUN PY 1995 VL 108 IS 2 SU S BP 45 EP 45 PG 1 WC Plant Sciences SC Plant Sciences GA RE289 UT WOS:A1995RE28900196 ER PT J AU VANHOVEN, RL NAM, SH MONTASER, A DOUGHTEN, MW DORRZAPF, AF AF VANHOVEN, RL NAM, SH MONTASER, A DOUGHTEN, MW DORRZAPF, AF TI DIRECT SOLID SAMPLING OF FIRE ASSAY BEADS BY SPARK ABLATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article ID ATOMIC-ABSORPTION SPECTROPHOTOMETRY; ELEMENTAL ANALYSIS; EMISSION-SPECTROMETRY; LASER ABLATION; GEOLOGIC MATERIALS; PRECIOUS METALS; NOBLE-METALS; PLATINUM; DISCHARGE; SPECTROSCOPY AB A spark-based, solid-sampling cell is described for inductively coupled plasma mass spectrometry (ICP-MS). The cell is devised for the direct sampling of gold and silver beads produced by the classical lead fire assay procedure. The sampler produces a solid aerosol composed of submicron-sized vapor condensates and small (< 2 mu m) spherules. In contrast to solution nebulization, the mass spectrum for spark-ICP-MS is relatively free of interfering metal oxide, polyatomic, and multiply-charged ions. The measurement precision is 3% RSD for Pt, Pd, and Rh preconcentrated into fire assay beads, but is 6% RSD for Ir due to its heterogeneous distribution in a silver bead. Detection limits determined for Pt, Pd, Rh, and Ir in fire assay beads range from 0.6 mu g/g (Pt) to 1.2 mu g/g (Pd). Calibration curves for these elements are linear up to the highest concentration in the bead studied (2000 mu g/g). The quantitative potential of the method is evaluated using the South African Reference Material (SARM-7) geologic standard. C1 GEORGE WASHINGTON UNIV,DEPT CHEM,WASHINGTON,DC 20052. US GEOL SURVEY,RESTON,VA 22092. NR 54 TC 14 Z9 14 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JUN PY 1995 VL 50 IS 4-7 BP 549 EP 564 DI 10.1016/0584-8547(94)00135-I PG 16 WC Spectroscopy SC Spectroscopy GA RD705 UT WOS:A1995RD70500024 ER PT J AU BELLIER, O ZOBACK, ML AF BELLIER, O ZOBACK, ML TI RECENT STATE OF STRESS CHANGE IN THE WALKER-LANE ZONE, WESTERN BASIN AND RANGE PROVINCE, UNITED-STATES SO TECTONICS LA English DT Review ID 1986 CHALFANT VALLEY; SAN-ANDREAS FAULT; EASTERN CALIFORNIA; GREAT-BASIN; EARTHQUAKE SEQUENCE; NORTHERN BASIN; MOJAVE-DESERT; DIXIE-VALLEY; SHEAR ZONE; FORE-ARC AB The NW to north-trending Walker Lane zone (WLZ) is located along the western boundary of the northern Basin and Range province with the Sierra Nevada. This zone is distinguished from the surrounding Basin and Range province on the basis of irregular topography and evidence for both normal and strike-slip Holocene faulting. Inversion of slip vectors from active faults, historic fault offsets, and earthquake focal mechanisms indicate two distinct Quaternary stress regimes within the WLZ, both of which are characterized by a consistent WNW sigma(3) axis; these are a normal faulting regime with a mean sigma(3) axis of N85 degrees +/- 9 degrees W and a mean stress ratio (R value) (R=(sigma(2)-sigma(1))/(sigma(3)-sigma(1))) of 0.63-0.74 and a younger strike-slip faulting regime with a similar mean sigma(3) axis (N65 degrees - 70 degrees W) and R values ranging between similar to 0.1 and 0.2. This younger regime is compatible with historic fault offsets and earthquake focal mechanisms. Both the extensional and strike-slip stress regimes reactivated inherited Mesozoic and Cenozoic structures and also produced new faults. The present-day strike-slip stress regime has produced strike-slip, normal oblique-slip, and normal dip-slip historic faulting. Previous workers have explained the complex interaction of active strike-slip, oblique, and normal faulting in the WLZ as a simple consequence of a single stress state with a consistent WNW sigma(3) axis and transitional between strike-slip and normal faulting (maximum horizontal stress approximately equal to vertical stress, or R approximate to O in both regimes) with minor local fluctuations. The slip data reported here support previous results from Owens Valley that suggest deformation within temporally distinct normal and strike-slip faulting stress regimes with a roughly constant WNW trending sigma(3) axis (Zoback, 1989). A recent change from a normal faulting to a strike-slip faulting stress regime is indicated by the crosscutting striae on faults in basalts <300,000 years old and is consistent with the dominantly strike-slip earthquake focal mechanisms and the youngest striae observed on faults in Plio-Quaternary deposits. Geologic control on the timing of the change is poor; it is impossible to determine if there has been a single recent absolute change or if there is, rather, an alternating or cyclical variation in stress magnitudes. Our slip data, in particular, the cross-cutting normal and strike-slip striae on the same fault plane, are inconsistent with postulated simple strain partitioning of deformation within a single regional stress field suggested for the WLZ by Wesnousky and Jones [1941] The location of the WLZ between the deep-seated regional extension of the Basin and Range and the right-lateral strike-slip regional tectonics of the San Andreas fault zone is probably responsible for the complex interaction of tectonic regimes in this transition zone. In early to mid-Tertiary time the WLZ appears to have had a similarly complex deformational. history, in this case as a back are or intra-arc region, accommodating at least part of the right-lateral component of oblique convergence as well as a component of extension. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP BELLIER, O (reprint author), UNIV PARIS 11,CNRS,URA D1369,BAT 509,F-91405 ORSAY,FRANCE. NR 102 TC 83 Z9 83 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD JUN PY 1995 VL 14 IS 3 BP 564 EP 593 DI 10.1029/94TC00596 PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF184 UT WOS:A1995RF18400002 ER PT J AU HACKER, BR DONATO, MM BARNES, CG MCWILLIAMS, MO ERNST, WG AF HACKER, BR DONATO, MM BARNES, CG MCWILLIAMS, MO ERNST, WG TI TIMESCALES OF OROGENY - JURASSIC CONSTRUCTION OF THE KLAMATH MOUNTAINS SO TECTONICS LA English DT Review ID NORTHERN SIERRA-NEVADA; OPHIOLITIC TECTONIC MELANGE; TRIASSIC SUBDUCTION COMPLEX; JOSEPHINE OPHIOLITE; FOOTHILLS TERRANE; METAMORPHIC BELT; NORTHEASTERN CALIFORNIA; CLOSURE TEMPERATURE; SOUTHWESTERN OREGON; FORK TERRANE AB Classical interpretations of orogeny were based on relatively imprecise biostratigraphic and isotopic age determinations that necessitated grouping apparently related features that may in reality have been greatly diachronous. Isotopic age techniques now have the precision required to resolve the timing of orogenic events on a scale much smaller than that of entire mountain belts. Forty-five new Ar-40/Ar-39 ages from the Klamath Mountains illuminate the deformation, metamorphism, magmatism, and sedimentation involved in the Jurassic construction of that orogen, leading to a new level of understanding regarding how preserved orogenic features relate to ancient plate tectonic processes. The new geochronologic relationships show that many Jurassic units of the Klamath Mountains had 200 Ma or older volcanoplutonic basement. Subsequent formation of a large similar to 170 Ma are was followed by contractional collapse of the are. Collision with a spreading ridge may have led to large-scale NW-SE extension in the central and northern Klamaths from 167 to similar to 155 Ma, coincident with the crystallization of voluminous plutonic and volcanic suites. Marked cooling of a large region of the central Klamath Mountains to below similar to 350 degrees C at similar to 150 Ma may have occurred as the igneous belt was extinguished by subduction of colder material at deeper structural levels. These data demonstrate that the Klamath Mountains-and perhaps other similar orogens-were constructed during areally and temporally variant episodes of contraction, extension, and magmatism that do not fit classical definitions of orogeny. C1 US GEOL SURVEY,MENLO PK,CA 94025. TEXAS TECH UNIV,DEPT GEOSCI,LUBBOCK,TX 79409. RP HACKER, BR (reprint author), STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305, USA. RI McWilliams, Michael/A-9548-2011; Hacker, Bradley/E-7750-2011 OI McWilliams, Michael/0000-0002-4107-7069; NR 154 TC 56 Z9 56 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD JUN PY 1995 VL 14 IS 3 BP 677 EP 703 DI 10.1029/94TC02454 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF184 UT WOS:A1995RF18400009 ER PT J AU BARTH, AP WOODEN, JL TOSDA, RM MORRISON, J DAWSON, DL HERNLY, BM AF BARTH, AP WOODEN, JL TOSDA, RM MORRISON, J DAWSON, DL HERNLY, BM TI ORIGIN OF GNEISSES IN THE AUREOLE OF THE SAN-GABRIEL ANORTHOSITE COMPLEX AND IMPLICATIONS FOR THE PROTEROZOIC CRUSTAL EVOLUTION OF SOUTHERN CALIFORNIA SO TECTONICS LA English DT Article ID SOUTHWESTERN UNITED-STATES; CONTACT-METAMORPHISM; ZIRCON SATURATION; NORTH-AMERICA; NAIN COMPLEX; GRANULITES; TEMPERATURE; CORDIERITE; DIABASE; GARNET AB Granulite facies gneisses along the southwestern margin of the San Gabriel anorthosite complex include compositionally banded, locally migmatitic felsic gneisses and mafic granulites, with rare interlayered augen gneiss and garnet+hypersthene+spinel aluminous gneiss. Previous workers accepted a 1.4 Ga age for these granulites and a 1.2 Ga age for the adjacent anorthosite complex and hence that this Proterozoic basement is allochthonous with respect to the southwestern United States part of the North American craton. Solvus geothermometry in felsic and mafic granulites yields minimum metamorphic temperatures of 900-950 degrees C, and new U-Pb zircon data yield a minimum metamorphic age of 1186 Ma, coincident with that of the adjacent anorthosite. We reinterpret these rocks as a 1190 Ma anorthosite complex and its granulite-grade thermal aureole. Geochemical data suggest that the anorthosite complex intruded Early Proterozoic rocks correlative with the Mojave crustal province, representing the North American craton exposed to the northeast. We conclude that these Proterozoic basement rocks represent the southwestern margin of the North American craton and not an exotic terrane accreted in Mesozoic or Tertiary time. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. UNIV SO CALIF, DEPT GEOL SCI, LOS ANGELES, CA 90089 USA. RP BARTH, AP (reprint author), INDIANA UNIV PURDUE UNIV, DEPT GEOL, 723 W MICHIGAN ST, INDIANAPOLIS, IN 46202 USA. NR 94 TC 14 Z9 14 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0278-7407 J9 TECTONICS JI Tectonics PD JUN PY 1995 VL 14 IS 3 BP 736 EP 752 DI 10.1029/94TC02901 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA RF184 UT WOS:A1995RF18400012 ER PT J AU COWARDIN, LM GOLET, FC AF COWARDIN, LM GOLET, FC TI US-FISH-AND-WILDLIFE-SERVICE 1979 WETLAND CLASSIFICATION - A REVIEW SO VEGETATIO LA English DT Article; Proceedings Paper CT IV International Wetlands Conference on Wetlands - Old World and New World CY 1992 CL COLUMBUS, OH DE CLASSIFICATION; DEFINITION; UNITED STATES; WETLAND ID WATER AB In 1979 the US Fish and Wildlife Service published and adopted a classification of wetlands and deepwater habitats of the United States. The system was designed for use in a national inventory of wetlands. It was intended to be ecologically based, to furnish the mapping units needed for the inventory, and to provide national consistency in terminology and definition. We review the performance of the classification after 13 years of use. The definition of wetland is based on national lists of hydric soils and plants that occur in wetlands. Our experience suggests that wetland classifications must facilitate mapping and inventory because these data gathering functions are essential to management and preservation of the wetland resource, but the definitions and taxa must have ecological basis. The most serious problem faced in construction of the classification was lack of data for many of the diverse wetland types. Review of the performance of the classification suggests that, for the most part, it was successful in accomplishing its objectives, but that problem areas should be corrected and modification could strengthen its utility. The classification, at least in concept, could be applied outside the United States. Experience gained in use of the classification can furnish guidance as to pitfalls to be avoided in the wetland classification process. C1 UNIV RHODE ISL,DEPT NAT RESOURCES SCI,KINGSTON,RI 02881. RP COWARDIN, LM (reprint author), US FISH & WILDLIFE SERV,PRAIRIE & NO WILDLIFE RES CTR,JAMESTOWN,ND 58401, USA. NR 40 TC 41 Z9 44 U1 4 U2 28 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0042-3106 J9 VEGETATIO JI Vegetatio PD JUN PY 1995 VL 118 IS 1-2 BP 139 EP 152 DI 10.1007/BF00045196 PG 14 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA RW036 UT WOS:A1995RW03600012 ER PT J AU WILEN, BO BATES, MK AF WILEN, BO BATES, MK TI THE US-FISH-AND-WILDLIFE-SERVICE NATIONAL WETLANDS INVENTORY PROJECT SO VEGETATIO LA English DT Article; Proceedings Paper CT IV International Wetlands Conference on Wetlands - Old World and New World CY 1992 CL COLUMBUS, OH DE DIGITIZING; PHOTO-INTERPRETATION; STATUS; TRENDS; WETLAND CLASSIFICATION; WETLAND MAPPING AB In 1974, the US Fish and Wildlife Service directed its Office of Biological Services to design and conduct an inventory of the Nation's wetlands. The mandate was to develop and disseminate a technically sound, comprehensive data base concerning the characteristics and extent of the Nation's wetlands. The purpose of this data base is to foster wise use of the Nation's wetlands and to expedite decisions that may affect this important resource. To accomplish this, state-of-the-art principles and methodologies pertaining to all aspects of wetland inventory were assimilated and developed by the newly formed project. By 1979, when the National Wetlands Inventory (NWI) Project became operational, it was clear that two very different kinds of information were needed. First, detailed wetland maps were needed for site-specific decisions. Second, national statistics developed through statistical sampling on the current status and trends of wetlands were needed in order to provide information to support the development or alteration of Federal programs and policies. The NWI has produced wetland maps (scale = 1:24 000) for 74% of the conterminous United States. It has also produced wetland maps (scale = 1:63 360) for 24% of Alaska. Nearly 9000 of these wetland maps, representing 16.7% of the continental United States, have been computerized (digitized). In addition to maps, the NWI has produced other valuable wetland products. These include a statistically-based report on the status and trends of wetlands that details gains and losses in United States wetlands that have occurred from the mid-1970's to the mid-1980's. Other wetland products include a list of wetland (hydric) soils, a national list of wetland plant species, wetland reports for certain individual States such as New Jersey and Florida, and a wetland values data base. RP WILEN, BO (reprint author), US FISH & WILDLIFE SERV,DEPT INTERIOR,NATL WETLANDS INVENTORY PROJECT,ROOM 400 ARLINGTON SQ,WASHINGTON,DC 20240, USA. NR 39 TC 48 Z9 55 U1 0 U2 15 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0042-3106 J9 VEGETATIO JI Vegetatio PD JUN PY 1995 VL 118 IS 1-2 BP 153 EP 169 DI 10.1007/BF00045197 PG 17 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA RW036 UT WOS:A1995RW03600013 ER PT J AU WRITER, JH LEENHEER, JA BARBER, LB AMY, GL CHAPRA, SC AF WRITER, JH LEENHEER, JA BARBER, LB AMY, GL CHAPRA, SC TI SEWAGE CONTAMINATION IN THE UPPER MISSISSIPPI RIVER AS MEASURED BY THE FECAL STEROL, COPROSTANOL SO WATER RESEARCH LA English DT Article DE COPROSTANOL; BED SEDIMENTS; MISSISSIPPI RIVER; SEWAGE; SURFACE WATERS; CONTAMINANT TRANSPORT; MODELING; POLLUTANTS ID SORPTIVE TOXIC-SUBSTANCES; FRESH-WATER SYSTEMS; SEDIMENTARY COPROSTANOL; ORGANIC POLLUTANTS; MODELS AB The molecular sewage indicator, coprostanol, was measured in bed sediments of the Mississippi River for the purpose of determining sewage contamination. Coprostanol is a non-ionic, non-polar, organic molecule that associates with sediments in surface waters, and concentrations of coprostanol in bed sediments provide an indication of long-term sewage loads. Because coprostanol concentrations are dependent on particle size and percent organic carbon, a ratio between coprostanol (sewage sources) and cholestanol + cholesterol (sewage and non-sewage sources) was used to remove the biases related to particle size and percent organic carbon. The dynamics of contaminant transport in the Upper Mississippi River are influenced by both hydrologic and geochemical parameters. A mass balance model incorporating environmental parameters such as river and tributary discharge, suspended sediment concentration, fraction of organic carbon, sedimentation rates, municipal discharges and coprostanol decay rates was developed that describes coprostanol concentrations and therefore, expected patterns of municipal sewage effects on the Upper Mississippi River. Comparison of the computed and the measured coprostanol concentrations provides insight into the complex hydrologic and geochemical processes of contaminant transport and the ability to link measured chemical concentrations with hydroiogic characteristics of the Mississippi River. C1 US GEOL SURVEY WRD,LAKEWOOD,CO 80225. PTI ENVIRONM SERV,BOULDER,CO. UNIV COLORADO,BOULDER,CO 80309. RI Chapra, Steven/A-5752-2008; OI Chapra, Steven/0000-0003-0238-6376; WRITER, JEFFREY/0000-0002-8585-8166 NR 25 TC 73 Z9 73 U1 0 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0043-1354 J9 WATER RES JI Water Res. PD JUN PY 1995 VL 29 IS 6 BP 1427 EP 1436 DI 10.1016/0043-1354(94)00304-P PG 10 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA QW061 UT WOS:A1995QW06100001 ER PT J AU EDMONDS, RL THOMAS, TB BLEW, RD AF EDMONDS, RL THOMAS, TB BLEW, RD TI BIOGEOCHEMISTRY OF AN OLD-GROWTH FORESTED WATERSHED, OLYMPIC NATIONAL-PARK, WASHINGTON SO WATER RESOURCES BULLETIN LA English DT Article DE WATER QUALITY; PRECIPITATION CHEMISTRY; THROUGHFALL; STEMFLOW; SOIL SOLUTION; STREAMWATER CHEMISTRY; TEMPERATE RAIN-FOREST ID DISSOLVED ORGANIC-CARBON; BRITISH-COLUMBIA; DOUGLAS-FIR; STREAMWATER CHEMISTRY; NITROGEN SATURATION; WESTERN OREGON; ECOSYSTEMS; SOIL; PRECIPITATION; MOUNTAINS AB The biogeochemistry of a coastal old-growth forested watershed in Olympic National Park, Washington, was examined. Objectives were to determine: (1) concentrations of major cations and anions and dissolved organic C (DOC) in precipitation, throughfall, stemflow, soil solution and the stream; (2) nutrient input/output budgets; and (3) nutrient retention mechanisms in the watershed. Stemflow was more acidic (pH 4.0-4.5) than throughfall (pH 5.1) and precipitation (pH 5.3). Organic acids were important contributors to acidity in throughfall and stemflow and tree species influenced pH. Soil solution pH averaged 6.2 at 40 cm depth. Stream pH was higher (7.6). Sodium (54.0 mu eq L(-1)) and Cl (57.6 mu eq L(-1)) were the dominant ions in precipitation, reflecting the close proximity to the ocean. Throughfall and stemflow were generally enriched in cations, especially K. Cation concentrations in soil solutions were generally less than those in stemflow. Ion concentrations increased in the stream. Dominant ions were Ca (759.7 mu eq L(-1)), Na (174.4 mu eq L(-1)), HCO3 (592.0 mu eq L(-1)), and SO4 (331.5 mu eq L(-1)) with seasonal peaks in the fall. Bedrock weathering strongly influenced stream chemistry. Highest average NO3 concentrations were in the stream (5.2 mu eq L(-1)) with seasonal peaks in the fall and lowest concentrations in the growing season. Nitrogen losses were similar to inputs; annual inputs were 4.8 kg/ha (not including fixation) and stream losses were 7.1 kg/ha. Despite the age and successional status of the forest, plant uptake is an important N retention mechanism in this watershed. C1 US FISH & WILDLIFE SERV,ECOL SERV,OLYMPIA,WA 98501. RP EDMONDS, RL (reprint author), UNIV WASHINGTON,COLL FOREST RESOURCES,SEATTLE,WA 98195, USA. NR 41 TC 39 Z9 44 U1 2 U2 17 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD JUN PY 1995 VL 31 IS 3 BP 409 EP 419 PG 11 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RF309 UT WOS:A1995RF30900007 ER PT J AU GREB, SR GRACZYK, DJ AF GREB, SR GRACZYK, DJ TI FREQUENCY-DURATION ANALYSIS OF DISSOLVED-OXYGEN CONCENTRATIONS IN 2 SOUTHWESTERN WISCONSIN STREAMS SO WATER RESOURCES BULLETIN LA English DT Article DE WATER QUALITY; STATISTICS; FREQUENCY ANALYSIS; NONPOINT SOURCE POLLUTION AB Historically, dissolved-oxygen (DO) data have been collected in the same manner as other water-quality constituents, typically at infrequent intervals as a grab sample or an instantaneous meter reading. Recent years have seen an increase in continuous water-quality monitoring with electronic dataloggers. This new technique requires new approaches in the statistical analysis of the continuous record. This paper presents an application of frequency-duration analysis to the continuous DO records of a cold and a warm water stream in rural southwestern Wisconsin. This method offers a quick, concise way to summarize large time-series data bases in an easily interpretable manner. Even though the two streams had similar mean DO concentrations, frequency-duration analyses showed distinct differences in their DO-concentration regime. This type of analysis also may be useful in relating DO concentrations to biological effects and in predicting low DO occurrences. C1 US GEOL SURVEY,MADISON,WI 53719. RP GREB, SR (reprint author), WISCONSIN DEPT NAT RESOURCES,1350 FEMRITE DR,MONONA,WI 53716, USA. NR 17 TC 4 Z9 4 U1 1 U2 4 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD JUN PY 1995 VL 31 IS 3 BP 431 EP 438 PG 8 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA RF309 UT WOS:A1995RF30900009 ER PT J AU KATZ, BG LEE, TM PLUMMER, LN BUSENBERG, E AF KATZ, BG LEE, TM PLUMMER, LN BUSENBERG, E TI CHEMICAL EVOLUTION OF GROUNDWATER NEAR A SINKHOLE LAKE, NORTHERN FLORIDA .1. FLOW PATTERNS, AGE OF GROUNDWATER, AND INFLUENCE OF LAKE WATER LEAKAGE SO WATER RESOURCES RESEARCH LA English DT Article ID CHLOROFLUOROCARBONS CCL3F; ALKALINITY REGULATION; HYDROLOGIC TRACERS; SEEPAGE LAKES; DATING TOOLS; ISOTOPE; SOLUBILITY; RECHARGE; SEAWATER; AQUIFER AB Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled karst setting in northern Florida. Stable isotope data indicated that the groundwater downgradient from the lake contained 11-67% lake water leakage, with a limit of detection of lake water in groundwater of 4.3%. The mixing fractions of lake water leakage, which passed through organic-rich sediments in the lake bottom, were directly proportional to the observed methane concentrations and increased with depth in the groundwater flow system. In aerobic groundwater upgradient from Lake Barco, CFC-modeled recharge dates ranged from 1987 near the water table to the mid 1970s for water collected at a depth of 30 m below the water table. CFC-modeled recharge dates (based on CFC-12) for anaerobic groundwater downgradient from the lake ranged from the late 1950s to the mid 1970s and were consistent with tritium data. CFC-modeled recharge dates based on CFC-11 indicated preferential microbial degradation in anoxic waters. Vertical hydraulic conductivities, calculated using CFC-12 modeled recharge dates and Darcy's law, were 0.17, 0.033, and 0.019 mid for the surficial aquifer, intermediate confining unit, and lake sediments, respectively. These conductivities agreed closely with those used in the calibration of a three-dimensional groundwater flow model for transient and steady state flow conditions. C1 US GEOL SURVEY,RESTON,VA 22092. US GEOL SURVEY,TAMPA,FL 33634. RP KATZ, BG (reprint author), US GEOL SURVEY,227 N BRONOUGH ST,SUITE 3015,TALLAHASSEE,FL 32301, USA. OI Plummer, L. Niel/0000-0002-4020-1013 NR 67 TC 59 Z9 60 U1 2 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 1995 VL 31 IS 6 BP 1549 EP 1564 DI 10.1029/95WR00221 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RB075 UT WOS:A1995RB07500011 ER PT J AU KATZ, BG PLUMMER, LN BUSENBERG, E REVESZ, KM JONES, BF LEE, TM AF KATZ, BG PLUMMER, LN BUSENBERG, E REVESZ, KM JONES, BF LEE, TM TI CHEMICAL EVOLUTION OF GROUNDWATER NEAR A SINKHOLE LAKE, NORTHERN FLORIDA .2. CHEMICAL-PATTERNS, MASS-TRANSFER MODELING, AND RATES OF MASS-TRANSFER REACTIONS SO WATER RESOURCES RESEARCH LA English DT Review ID CARBON ISOTOPIC COMPOSITION; COASTAL-PLAIN; SULFATE REDUCTION; INORGANIC CARBON; GRAVEL AQUIFER; SOUTH-CAROLINA; WATER; METHANE; GEOCHEMISTRY; SEDIMENTS AB Chemical patterns along evolutionary groundwater flow paths in silicate and carbonate aquifers were interpreted using solute tracers, carbon and sulfur isotopes, and mass balance reaction modeling for a complex hydrologic system;involving groundwater inflow to and outflow from a sinkhole lake in northern Florida. Rates of dominant reactions along defined flow paths were estimated from modeled mass transfer and ages obtained from CFC-modeled recharge dates. Groundwater upgradient from Lake Barco remains ode as it moves downward, reacting with silicate minerals in a system open to carbon dioxide (CO2), producing only small increases in dissolved species. Beneath and downgradient of Lake Barco the oxic groundwater mixes with lake water leakage in a highly reducing, silicate-carbonate mineral environment. A mixing model, developed for anoxic groundwater downgradient from the lake, accounted for the observed chemical and isotopic composition by combining different proportions of lake water leakage and infiltrating meteoric water. The evolution of major ion chemistry and the C-13 isotopic composition of dissolved carbon species in groundwater downgradient from the lake can be explained by the aerobic oxidation of organic matter in the lake, anaerobic microbial oxidation of organic carbon, and incongruent dissolution of smectite minerals to kaolinite. The dominant process for the generation of methane was by the CO2 reduction pathway based on the isotopic composition of hydrogen (delta(2)H(CH4) = -186 to -234 parts per thousand) and carbon (delta(13)C(CH4) = -65.7 to -72.3 parts per thousand). Rates of microbial metabolism of organic matter, estimated from the mass transfer reaction models, ranged from 0.0047 to 0.039 mmol L(-1) yr(-1) for groundwater downgradient from the lake. C1 US GEOL SURVEY,RESTON,VA 22092. US GEOL SURVEY,TAMPA,FL 33634. RP KATZ, BG (reprint author), US GEOL SURVEY,227 N BRONOUGH ST,SUITE 3015,TALLAHASSEE,FL 32301, USA. OI Plummer, L. Niel/0000-0002-4020-1013 NR 101 TC 28 Z9 30 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 1995 VL 31 IS 6 BP 1565 EP 1584 DI 10.1029/95WR00220 PG 20 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RB075 UT WOS:A1995RB07500012 ER PT J AU RUBIN, DM MCDONALD, RR AF RUBIN, DM MCDONALD, RR TI NONPERIODIC EDDY PULSATIONS SO WATER RESOURCES RESEARCH LA English DT Article ID GRAND-CANYON; TIME-SERIES; TURBULENCE; CHAOS; FLOW; SEPARATION; SYSTEM; LAYER AB Recirculating flow in lateral separation eddies is typically weaker than main stem flow and provides an effective environment for trapping sediment. Observations of recirculating flow and sedimentary structures demonstrate that eddies pulsate in size and in flow velocity even when main stem flow is steady. Time series measurements of flow velocity and location of the reattachment point indicate that these pulsations are nonperiodic. Nonperiodic flow in the lee of a channel margin constriction is grossly different from the periodic flow in the lee of a cylinder that is isolated in a flow. Our experiments demonstrate that placing a flow-parallel plate adjacent to a cylinder is sufficient to cause the leeside flow to change from a periodic sequence of vortices to a nonperiodically pulsating lateral separation eddy, even if flow conditions are otherwise unchanged. Two processes cause the leeside flow to become nonperiodic when the plate is added. First, vortices that are shed from the cylinder deform and become irregular as they impact the plate or interfere with remnants of other vortices near the reattachment point. Second, these deformed vortices and other flow structures are recirculated in the lateral separation eddy, thereby influencing the future state (pressure and momentum distribution) of the recirculating flow. The vortex deformation process was confirmed experimentally by documenting spatial differences in leeside flow; vortex shedding that is evident near the separation point is undetectable near the reattachment point. Nonlinear forecasting techniques were used in an attempt to distinguish among several possible kinds of nonperiodic flows. The computational techniques were unable to demonstrate that any of the nonperiodic flows result from low-dimensional nonlinear processes. RP US GEOL SURVEY, MAIL STOP 999, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. OI McDonald, Richard/0000-0002-0703-0638 NR 46 TC 12 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 EI 1944-7973 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 1995 VL 31 IS 6 BP 1595 EP 1605 DI 10.1029/95WR00472 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA RB075 UT WOS:A1995RB07500014 ER PT J AU DOLTON, DD AF DOLTON, DD TI THOUGHTS IN ADVANCE SO WILDLIFE SOCIETY BULLETIN LA English DT Letter RP DOLTON, DD (reprint author), US FISH & WILDLIFE SERV,LAUREL,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD SUM PY 1995 VL 23 IS 2 BP 136 EP 136 PG 1 WC Biodiversity Conservation SC Biodiversity & Conservation GA RK411 UT WOS:A1995RK41100002 ER PT J AU BUTLER, WI STEHN, RA BALOGH, GR AF BUTLER, WI STEHN, RA BALOGH, GR TI GIS FOR MAPPING WATERFOWL DENSITY AND DISTRIBUTION FROM AERIAL SURVEYS SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE AERIAL SURVEY; ALASKA; DENSITY; DISTRIBUTION; GEOGRAPHIC INFORMATION SYSTEM; CIS; GLOBAL POSITIONING SYSTEM; CPS; MAPPING; WATERFOWL ID GEOGRAPHIC INFORMATION-SYSTEM AB We describe a CIS (geographic information system) that combines a personal computer, a color printer, a color plotter, aerial survey data, software for programming, standard mapping, and 3-dimensional mapping. It allows us to display: (1) geographic locations of observations; (2) isopleths showing the distribution and relative density for each species or group of species; (3) changes in distribution; (4) changes in bird density; and (5) isopleth overlays on data layers such as land ownership. Our method of analyzing and graphically presenting waterfowl location data has increased the use, effectiveness, and application of multi-species aerial surveys in Alaska. These techniques should be equally useful outside Alaska. C1 US FISH & WILDLIFE SERV,ANCHORAGE,AK 99503. NR 26 TC 8 Z9 11 U1 2 U2 3 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD SUM PY 1995 VL 23 IS 2 BP 140 EP 147 PG 8 WC Biodiversity Conservation SC Biodiversity & Conservation GA RK411 UT WOS:A1995RK41100005 ER PT J AU BUTLER, WI HODGES, JI STEHN, RA AF BUTLER, WI HODGES, JI STEHN, RA TI LOCATING WATERFOWL OBSERVATIONS ON AERIAL SURVEYS SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE AERIAL SURVEY; ALASKA; DISTRIBUTION; GEOGRAPHIC INFORMATION SYSTEM; GIS; GLOBAL POSITIONING SYSTEM; GPS; LONG-RANGE NAVIGATION; LORAN; OBSERVATIONS; SAMPLING; TRANSECTS; WATERFOWL ID BREEDING-GROUND SURVEY; VISIBILITY BIAS; CANADA GEESE AB We modified standard aerial survey data collection to obtain the geographic location for each waterfowl observation on surveys in Alaska during 1987-1993. Using transect navigation with CPS (global positioning system), data recording on continuously running tapes, and a computer data input program, we located observations with an average deviation along transects of 214 m. The method provided flexibility in survey design and data analysis. Although developed for geese nesting near the coast of the Yukon-Kuskokwim Delta, the methods are widely applicable and were used on other waterfowl surveys in Alaska to map distribution and relative abundance of waterfowl. Accurate location data with GIS analysis and display may improve precision and usefulness of data from any aerial transect survey. C1 US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT PROJECT,ANCHORAGE,AK 99503. US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT PROJECT,JUNEAU,AK 99802. NATL BIOL SERV,ALASKA SCI CTR,ANCHORAGE,AK 99503. NR 18 TC 12 Z9 12 U1 0 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD SUM PY 1995 VL 23 IS 2 BP 148 EP 154 PG 7 WC Biodiversity Conservation SC Biodiversity & Conservation GA RK411 UT WOS:A1995RK41100006 ER PT J AU PITOCCHELLI, J PIATT, J CRONIN, MA AF PITOCCHELLI, J PIATT, J CRONIN, MA TI MORPHOLOGICAL AND GENETIC-DIVERGENCE AMONG ALASKAN POPULATIONS OF BRACHYRAMPHUS MURRELETS SO WILSON BULLETIN LA English DT Article ID MITOCHONDRIAL-DNA; EVOLUTION AB We studied morphological and mitochondrial DNA (mtDNA) divergence among three populations of Brachyramphus Murrelets: Kittlitz's Murrelets (B. brevirostris), and tree-nesting and ground-nesting Marbled Murrelets (B. marmoratus). We found little morphological divergence in external and skeletal measurements among Marbled Murrelets, but both populations were easily distinguished from Kittlitz's Murrelets. Principal components analysis (PCA) of external measurements showed that Kittlitz's Murrelets occupied a distinct cloud in multivariate space separate from Marbled Murrelets. However, tree-nesting and ground-nesting Marbled Murrelets were indistinguishable. We obtained the same pattern from PCA of skeletal dimensions. Analysis of mtDNA revealed an estimate of sequence divergence of 4.4%-5.0% between Marbled Murrelets and Kittlitz's Murrelets, suggesting a divergence of about 2.2 MYBP. The difference between ground- and tree-nesting murrelets was 0.03%. This analysis suggests little divergence has occurred between tree- and ground-nesting populations of Marbled Murrelets. C1 AMER MUSEUM NAT HIST,DEPT ORNITHOL,NEW YORK,NY 10024. US FISH & WILDLIFE SERV,RES CTR,NATL BIOL SURVEY,ANCHORAGE,AK 99503. RP PITOCCHELLI, J (reprint author), ST ANSELM COLL,DEPT BIOL,100 ST ANSELM DR,MANCHESTER,NH 03102, USA. NR 26 TC 8 Z9 8 U1 0 U2 0 PU WILSON ORNITHOLOGICAL SOC PI ANN ARBOR PA MUSEUM OF ZOOLOGY UNIV MICHIGAN, ANN ARBOR, MI 48109 SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD JUN PY 1995 VL 107 IS 2 BP 235 EP 250 PG 16 WC Ornithology SC Zoology GA RC272 UT WOS:A1995RC27200003 ER PT J AU COPLEN, TB AF COPLEN, TB TI DISCONTINUANCE OF SMOW AND PDB SO NATURE LA English DT Letter RP COPLEN, TB (reprint author), US GEOL SURVEY,INT UNION PURE & APPL CHEM,COMMISS ATOM WEIGHTS & ISOTOP ABUNDANCES,959 NATL CTR,RESTON,VA 22092, USA. NR 2 TC 108 Z9 109 U1 1 U2 17 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAY 25 PY 1995 VL 375 IS 6529 BP 285 EP 285 DI 10.1038/375285a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA RA030 UT WOS:A1995RA03000031 ER EF