FN Thomson Reuters Web of Science™ VR 1.0 PT S AU DWYER, WP LEARY, RF AF DWYER, WP LEARY, RF BE Schramm, HL Piper, RG TI Broodstock development plan for the fluvial arctic grayling in Montana SO USES AND EFFECTS OF CULTURED FISHES IN AQUATIC ECOSYSTEMS SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Meeting Abstract CT International Symposium and Workshop on the Uses and Effects of Cultured Fishes in Aquatic Ecosystems CY MAR 12-17, 1994 CL ALBUQUERQUE, NM SP Amer Fisheries Soc C1 US FISH & WILDLIFE SERV,BOZEMAN,MT 59715. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-91-1 J9 AM FISH S S PY 1995 VL 15 BP 570 EP 570 PG 1 WC Fisheries SC Fisheries GA BD89Y UT WOS:A1995BD89Y00073 ER PT B AU Swanson, RB AF Swanson, RB BE Campbell, KL TI Methods for monitoring physical, chemical, and biological characteristics at selected wetlands in the Platte River Basin, Nebraska SO VERSATILITY OF WETLANDS IN THE AGRICULTURAL LANDSCAPE SE ASAE PUBLICATION LA English DT Proceedings Paper CT Conference on Versatility of Wetlands in the Agricultural Landscape CY SEP 17-20, 1995 CL TAMPA, FL SP Soc Engn Agr Food & Biol Syst, Amer Water Resources Assoc DE wetlands; methods; sampling; water quality; pesticides; triazine herbicides; trace elements; tissue C1 US GEOL SURVEY,N PLATTE,NE. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 BN 0-929355-69-5 J9 ASAE PUBL PY 1995 VL 95 IS 9 BP 515 EP 524 PG 10 WC Agriculture, Dairy & Animal Science; Agricultural Economics & Policy; Agronomy; Engineering, Environmental; Water Resources SC Agriculture; Engineering; Water Resources GA BE55L UT WOS:A1995BE55L00051 ER PT B AU Lee, KE Huggins, DG Thurman, EM AF Lee, KE Huggins, DG Thurman, EM BE Campbell, KL TI Effects of hydrophyte community structure on atrazine and alachlor degradation in wetlands SO VERSATILITY OF WETLANDS IN THE AGRICULTURAL LANDSCAPE SE ASAE PUBLICATION LA English DT Proceedings Paper CT Conference on Versatility of Wetlands in the Agricultural Landscape CY SEP 17-20, 1995 CL TAMPA, FL SP Soc Engn Agr Food & Biol Syst, Amer Water Resources Assoc DE atrazine; alachlor; degradation; wetlands; hydrophytes; community structure C1 US GEOL SURVEY,LAWRENCE,KS. NR 0 TC 3 Z9 4 U1 0 U2 1 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 BN 0-929355-69-5 J9 ASAE PUBL PY 1995 VL 95 IS 9 BP 525 EP 538 PG 14 WC Agriculture, Dairy & Animal Science; Agricultural Economics & Policy; Agronomy; Engineering, Environmental; Water Resources SC Agriculture; Engineering; Water Resources GA BE55L UT WOS:A1995BE55L00052 ER PT B AU Frankforter, JD AF Frankforter, JD BE Campbell, KL TI Association between local land use and herbicide concentrations in wetlands of the Platte river Basin, Nebraska SO VERSATILITY OF WETLANDS IN THE AGRICULTURAL LANDSCAPE SE ASAE PUBLICATION LA English DT Proceedings Paper CT Conference on Versatility of Wetlands in the Agricultural Landscape CY SEP 17-20, 1995 CL TAMPA, FL SP Soc Engn Agr Food & Biol Syst, Amer Water Resources Assoc DE wetlands; land use; atrazine; herbicides; Platte River C1 US GEOL SURVEY,LINCOLN,NE. NR 0 TC 0 Z9 1 U1 1 U2 1 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 BN 0-929355-69-5 J9 ASAE PUBL PY 1995 VL 95 IS 9 BP 539 EP 547 PG 9 WC Agriculture, Dairy & Animal Science; Agricultural Economics & Policy; Agronomy; Engineering, Environmental; Water Resources SC Agriculture; Engineering; Water Resources GA BE55L UT WOS:A1995BE55L00053 ER PT B AU Benham, BL Mote, CR AF Benham, BL Mote, CR BE Campbell, KL TI Treating livestock waste with laboratory-scale constructed wetlands SO VERSATILITY OF WETLANDS IN THE AGRICULTURAL LANDSCAPE SE ASAE PUBLICATION LA English DT Proceedings Paper CT Conference on Versatility of Wetlands in the Agricultural Landscape CY SEP 17-20, 1995 CL TAMPA, FL SP Soc Engn Agr Food & Biol Syst, Amer Water Resources Assoc DE constructed wetlands; waste treatment; dairy waste C1 US GEOL SURVEY,KNOXVILLE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 BN 0-929355-69-5 J9 ASAE PUBL PY 1995 VL 95 IS 9 BP 635 EP 646 PG 12 WC Agriculture, Dairy & Animal Science; Agricultural Economics & Policy; Agronomy; Engineering, Environmental; Water Resources SC Agriculture; Engineering; Water Resources GA BE55L UT WOS:A1995BE55L00062 ER PT J AU PETERS, NE LEAVESLEY, GH AF PETERS, NE LEAVESLEY, GH TI BIOTIC AND ABIOTIC PROCESSES CONTROLLING WATER CHEMISTRY DURING SNOWMELT AT RABBIT-EARS-PASS, ROCKY-MOUNTAINS, COLORADO, USA SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT BIOGEOMON, International Symposium on Ecosystem Behavior and the Evaluation of Integrated Monitoring of Small Catchments CY SEP 18-20, 1993 CL PRAGUE, CZECH REPUBLIC ID CENTRAL ADIRONDACK MOUNTAINS; NEW-YORK; ATMOSPHERIC DEPOSITION; CANOPY INTERACTIONS; SCOTTISH HIGHLANDS; SPRING SNOWMELT; WILDERNESS AREA; CENTRAL ONTARIO; SIERRA-NEVADA; NATIONAL-PARK AB The chemical composition of snowmelt, groundwater, and streamwater was monitored during the spring of 1991 and 1992 in a 200-ha subalpine catchment on the western flank of the Rocky Mountains near Steamboat Springs, colorado. Most of the snowmelt occurred during a one-month period annually that began in mid-May 1991 and mid-April 1992. The average water quality characteristics of individual sampling sites (meltwater, streamwater, and groundwater) were similar in 1991 and 1992. The major ions in meltwater were differentially eluted from the snowpack, and meltwater was dominated by Ca2+, SO42-, and NO3-. Groundwater and streamwater were dominated by weathering products, including Ca2+, HCO3- (measured as alkalinity), and SiO2, and their concentrations decreased as snowmelt progressed. One well had extremely high NO3- concentrations, which were balanced by Ca2+ concentrations. For this well, hydrogen ion was hypothesized to be generated from nitrification in overlying soils, and subsequently exchanged with other rations, particularly Ca2+. Solute concentrations in streamwater also decreased as snowmelt progressed. Variations in groundwater levels and solute concentrations indicate that most of the meltwater traveled through the surficial materials. A mass balance for 1992 indicated that the watershed retained H+, NH4+, NO3-, SO42- and Cl- and was the primary source of base cations acid other weathering products. Proportionally more SO42- was deposited with the unusually high summer rainfall in 1992 compared to that released from snowmelt, whereas NO3- was higher in snowmelt and Cl- was the same. The sum of snowmelt and rainfall could account for greater than 90% of the H+ and NH4+ retained by the watershed and greater than 50% of the NO3-. C1 US GEOL SURVEY,WRD,DENVER FED CTR,LAKEWOOD,CO 80225. RP PETERS, NE (reprint author), US GEOL SURVEY,WRD,3039 AMWILER RD,SUITE 130,ATLANTA,GA 30360, USA. NR 49 TC 15 Z9 15 U1 0 U2 3 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 JAN PY 1995 VL 79 IS 1-4 BP 171 EP 190 DI 10.1007/BF01100436 PG 20 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA QU753 UT WOS:A1995QU75300011 ER PT J AU FINLEY, JB DREVER, JI TURK, JT AF FINLEY, JB DREVER, JI TURK, JT TI SULFUR ISOTOPE DYNAMICS IN A HIGH-ELEVATION CATCHMENT, WEST GLACIER LAKE, WYOMING SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT BIOGEOMON, International Symposium on Ecosystem Behavior and the Evaluation of Integrated Monitoring of Small Catchments CY SEP 18-20, 1993 CL PRAGUE, CZECH REPUBLIC ID SULFATE ADSORPTION; SOIL; FOREST; ECOSYSTEM; SNOWPACK; RATIOS; WATER AB Stable isotopes of S are used in conjunction with dissolved SO42- concentrations to evaluate the utility of delta(34)S ratios in tracing contributions of bedrock-derived S to SO42- in runoff. Water samples were collected over the annual hydrograph from two tributaries in the West Glacier Lake, Wyoming, catchment. Concentrations of SO42- ranged from 12.6 to 43.0 mu eq L(-1); delta(34)S ratios ranged from -1.8 parts per thousand to +4.9 parts per thousand. The delta(34)S value of atmospherically derived SO42- is about +5.6 parts per thousand; four samples of pyrite from the bedrock had delta(34)S ratios that ranged from +0.7 to +4.1 parts per thousand. Concentrations of SO42- were inversely related to delta(34)S and discharge. The data for the tributary with the higher SO42- concentrations were reasonably consistent with mixing between atmospheric S and S from a bedrock source with a delta(34)S ratio of about -4.5 parts per thousand, The difference from the measured bedrock values presumably indicates that S isotopes in the bedrock pyrite are heterogeneously distributed. The data from the tributary with lower SO42- concentrations did not follow a two-component mixing line. Deviation from a two-component mixing line is most likely caused by preferential elution of SO42- from the snowpack during the early stages of snowmelt, although microbially mediated fractionation of S isotopes in the soil zone also may cause the deviation from the mixing line. Sulfur isotopes are useful in identifying whether or not there is a substantial contribution of bedrock S to runoff, but quantifying that contribution is problematic. C1 UNIV WYOMING,DEPT GEOL & GEOPHYS,LARAMIE,WY 82071. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 27 TC 13 Z9 14 U1 0 U2 2 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 JAN PY 1995 VL 79 IS 1-4 BP 227 EP 241 DI 10.1007/BF01100439 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA QU753 UT WOS:A1995QU75300014 ER PT B AU Lull, KJ Tindall, JA Potts, DF AF Lull, KJ Tindall, JA Potts, DF BE Heatwole, C TI A GIS application for assessment of non-point-source pollution risk on managed forest lands SO WATER QUALITY MODELING - PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM SE ASAE PUBLICATION LA English DT Proceedings Paper CT International Symposium on Water Quality Modeling CY APR 02-05, 1995 CL ORLANDO, FL SP Amer Soc Agr Engineers, Soc Engn Agri Food & Biol Syst, Amer Agr Econ Assoc, Amer Soc Agron, Amer Soc Civil Engineers, Amer Water Resources Assoc, Soc Environm Toxicol & Chem, Soil Sci Soc Amer, USDA, ARS, USDA, CSRS, USDA, SCS DE geographic information systems; non-point source pollution; risk analysis C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 BN 0-929355-64-4 J9 ASAE PUBL PY 1995 VL 95 IS 5 BP 491 EP 502 PG 12 WC Agronomy; Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Environmental Sciences; Soil Science; Water Resources SC Agriculture; Computer Science; Engineering; Environmental Sciences & Ecology; Water Resources GA BF39P UT WOS:A1995BF39P00052 ER PT B AU Dorava, JM Waythomas, CF AF Dorava, JM Waythomas, CF BE Herrmann, W Back, W Sidle, RC Johnson, AI TI Hydrologic hazards at recently active volcanoes in the Cook inlet region, Alaska SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE Alaska; Cook Inlet; volcano; hydrologic hazards; lahar; tsunami C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 91 EP 98 PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00011 ER PT B AU McCabe, GJ Fountain, AG AF McCabe, GJ Fountain, AG BE Herrmann, W Back, W Sidle, RC Johnson, AI TI Relations between winter 700-mb height anomalies and mass balance of South Cascade Glacier, Washington SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE glacier; atmospheric circulation C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 173 EP 182 PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00019 ER PT B AU Dettinger, MD Schaefer, DH AF Dettinger, MD Schaefer, DH BE Herrmann, W Back, W Sidle, RC Johnson, AI TI Decade-scale hydroclimatic forcing of ground-water levels in the central Great Basin, Eastern Nevada SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE hydroclimatology; ground water levels; precipitation; Nevada C1 US GEOL SURVEY,SAN DIEGO,CA 92123. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 195 EP 204 PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00021 ER PT B AU Meyer, W Souza, WR AF Meyer, W Souza, WR BE Herrmann, W Back, W Sidle, RC Johnson, AI TI That control the amount of water that can be diverted to wells in a high-level aquifer SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE Hawaii; ground water; volcanic dikes; ground-water model C1 US GEOL SURVEY,HONOLULU,HI 96813. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 207 EP 216 PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00022 ER PT B AU Hunt, CD Spengler, SR Gingerich, SB AF Hunt, CD Spengler, SR Gingerich, SB BE Herrmann, W Back, W Sidle, RC Johnson, AI TI Lithologic influences on freshwater lens geometry and aquifer tidal response at Kwajalein Atoll SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE Kwajalein; Marshall Islands; atoll; hydrogeology; freshwater lens; aquifer tidal response C1 US GEOL SURVEY,HONOLULU,HI 96813. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 267 EP 276 PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00028 ER PT B AU Wright, WG AF Wright, WG BE Herrmann, W Back, W Sidle, RC Johnson, AI TI Nitrogen fertilizer as an oxidizing agent to mobilize trace constituents from soil SO WATER RESOURCES AND ENVIRONMENTAL HAZARDS: EMPHASIS ON HYDROLOGIC AND CULTURAL INSIGHT IN THE PACIFIC RIM, PROCEEDINGS LA English DT Proceedings Paper CT American-Water-Resources-Association Annual Summer Symposium on Water Resources and Environmental Hazards - Emphasis on Hydrologic and Cultural Insight in the Pacific Rim CY JUN 25-28, 1995 CL HONOLULU, HI SP Amer Water Resources Assoc, East West Ctr, Hawaii State Commiss Water Resource Management, Honolulu Board Water Supply, Int Assoc Hydrogeologists, Int Water Resources Assoc, Natl Biol Serv, Natl Sci Fdn, Org Amer States, UNESCO, UN Environm Program, US Fish & Wildlife Serv, US Geol Survey, US Nat Resources Conservat Serv, Univ Council Water Resources, Univ Hawaii Water Resources Res Ctr, World Bank DE anthropogenic effects; irrigation; water quality C1 US GEOL SURVEY,DIV WATER RESOURCES,DURANGO,CO 81301. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN WATER RESOURCES ASSOCIATION PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 BN 1-882132-33-5 PY 1995 BP 483 EP 490 PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BE81C UT WOS:A1995BE81C00050 ER PT B AU Thomas, WO Kuriki, M Suetsugi, T AF Thomas, WO Kuriki, M Suetsugi, T BE Espey, WH Combs, PG TI An evaluation of frequency distributions for flood hazard analysis SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 124 EP 128 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00026 ER PT B AU Baltzer, RA Schaffranek, RW Lai, CT AF Baltzer, RA Schaffranek, RW Lai, CT BE Espey, WH Combs, PG TI Robustness of de Saint Venant equations for simulating unsteady flows SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 139 EP 144 PG 6 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00029 ER PT B AU Blodgett, JC Nasseri, I AF Blodgett, JC Nasseri, I BE Espey, WH Combs, PG TI Precipitation depth-duration characteristics, Antelope Valley, California SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,SACRAMENTO,CA 95825. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 274 EP 278 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00056 ER PT B AU Dunn, DD AF Dunn, DD BE Espey, WH Combs, PG TI Assessment of nutrient loads in streamflow to the Gulf of Mexico SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,AUSTIN,TX 78754. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 378 EP 378 PG 1 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00076 ER PT B AU Fischer, EE AF Fischer, EE BE Espey, WH Combs, PG TI Contraction scour at a bridge over Wolf Creek, Iowa SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,IOWA CITY,IA 52244. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 430 EP 434 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00087 ER PT B AU Hale, TW Stamey, TC AF Hale, TW Stamey, TC BE Espey, WH Combs, PG TI Flooding in southeastern United States from Tropical Storm Alberto, July 1994 SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,ATLANTA,GA 30360. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 765 EP 769 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00153 ER PT B AU Fulford, JM AF Fulford, JM BE Espey, WH Combs, PG TI Effects of pulsating flow on current meter performance SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,BAY ST LOUIS,MS. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 BN 0-7844-0108-X PY 1995 BP 917 EP 921 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00184 ER PT B AU Holmes, RR Ghere, DG Dunn, CJ AF Holmes, RR Ghere, DG Dunn, CJ BE Espey, WH Combs, PG TI Simplified method for estimating total streambed scour at bridges in Illinois SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,URBANA,IL 61801. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 1046 EP 1050 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00210 ER PT B AU Robinson, JB Bales, JD Young, WS AF Robinson, JB Bales, JD Young, WS BE Espey, WH Combs, PG TI Advanced instrumentation for the collection, retrieval, and processing of urban stormwater data SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,CHARLOTTE,NC 28217. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 1081 EP 1085 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00217 ER PT B AU Guay, JR AF Guay, JR BE Espey, WH Combs, PG TI Hydrologic effects of increased urbanization SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,SACRAMENTO,CA 95825. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 1193 EP 1197 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00239 ER PT B AU Oberg, KA Fisk, GG AF Oberg, KA Fisk, GG BE Espey, WH Combs, PG TI Measurements of velocity and discharge, Grand Canyon, Arizona, May 1994 SO WATER RESOURCES ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1st International Conference on Water Resources Engineering CY AUG 14-18, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Inst Hydrol, Amer Soc Civil Engineers, Environm Engn Div, Amer Soc Civil Engineers, Water Resources Planning & Management Div, Amer Soc Civil Engineers, Waterway Port Coastal & Ocean Div, Amer Water Resources Assoc, Canadian Soc Civil Engn, Int Assoc Hydraul Res, US Geol Survey, US Bur Reclamat, Nat Resources Conservat Serv, Soc Range Conservat, Soil & Water Conservat Soc, Texas Water Dev Board, Texas Nat Resource Conservat Commiss C1 US GEOL SURVEY,URBANA,IL 61801. NR 0 TC 0 Z9 0 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 0-7844-0108-X PY 1995 BP 1774 EP 1778 PG 5 WC Engineering, Environmental; Engineering, Civil; Water Resources SC Engineering; Water Resources GA BE48Z UT WOS:A1995BE48Z00353 ER PT J AU TIEDEMAN, CR HSIEH, PA CHRISTIAN, SB AF TIEDEMAN, CR HSIEH, PA CHRISTIAN, SB TI CHARACTERIZATION OF A HIGH-TRANSMISSIVITY ZONE BY WELL TEST ANALYSIS - STEADY-STATE CASE SO WATER RESOURCES RESEARCH LA English DT Article ID PUMPING TESTS; NONUNIFORM AQUIFERS AB A method is developed to analyze steady horizontal flow to a well pumped from a confined aquifer composed of two homogeneous zones with contrasting transmissivities. Zone 1 is laterally unbounded and encloses zone 2, which is elliptical in shape and is several orders of magnitude more transmissive than zone 1. The solution for head is obtained by the boundary integral equation method. Nonlinear least squares regression is used to estimate the model parameters, which include the transmissivity of zone 1, and the location, size, and orientation of zone 2. The method is applied to a hypothetical aquifer where zone 2 is a long and narrow zone of vertical fractures. Synthetic data are generated from three different well patterns, representing different areal coverage and proximity to the fracture zone. When zone 1 of the hypothetical aquifer is homogeneous, the method correctly estimates all model parameters. When zone 1 is a randomly heterogeneous transmissivity field, some parameter estimates, especially the length of zone 2, become highly uncertain. To reduce uncertainty, the pumped well should be close to the fracture zone, and surrounding observation wells should cover an area similar in dimension to the length of the fracture zone. Some prior knowledge of the fracture zone, such as that gained from a surface geophysical survey, would greatly aid in designing the well test. RP TIEDEMAN, CR (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 496,MENLO PK,CA 94025, USA. NR 17 TC 9 Z9 9 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 JAN PY 1995 VL 31 IS 1 BP 27 EP 37 DI 10.1029/94WR01965 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA QF693 UT WOS:A1995QF69300004 ER PT J AU WENTZ, DA ROSE, WJ WEBSTER, KE AF WENTZ, DA ROSE, WJ WEBSTER, KE TI LONG-TERM HYDROLOGIC AND BIOGEOCHEMICAL RESPONSES OF A SOFT-WATER SEEPAGE LAKE IN NORTH CENTRAL WISCONSIN SO WATER RESOURCES RESEARCH LA English DT Article ID ESTIMATING GROUNDWATER EXCHANGE; ACID-NEUTRALIZING CAPACITY; SANDY SILICATE AQUIFER; CHEMICAL EVOLUTION; BALANCE; ACIDIFICATION; PRECIPITATION; PHOSPHORUS; FLORIDA; MODEL AB Hydrologic and chemical budgets were determined for the period October 1980 through September 1988 for Vandercook Lake, a 43-ha soft water seepage lake located in predominantly sandy outwash in northern Wisconsin. The 1951-1980 mean annual precipitation for the lake, based on nearby National Weather Service (NWS) Stations, was 825 mm; volume-weighted pH of bulk atmospheric deposition during the 8-year study averaged 4.7. From October 1980 through September 1983, annual precipitation was 108% of the 30-year NWS average, annual recharge was 144% of the 8-year study period average, and annual groundwater inflow to the lake ranged from 5 to 9% of the total inflow. From October 1986 through September 1988, annual precipitation was 90% of the NWS average, annual recharge was 30% of the study period average, and; the lake received no groundwater inflow; During the study, the lake changed from a system whose buffering mechanism was significantly influenced by mineral weathering in inflowing groundwater to one dominated by in-lake sulfate reduction. The functional differences exhibited by this lake during the 8 years of study demonstrate the tenuousness with which conclusions based on shorter-term studies of similar systems must be considered. C1 US GEOL SURVEY,MADISON,WI 53719. WISCONSIN DEPT NAT RESOURCES,MONONA,WI 53716. RP WENTZ, DA (reprint author), US GEOL SURVEY,10615 SE CHERRY BLOSSOM DR,PORTLAND,OR 97216, USA. OI Webster, Katherine/0000-0002-6009-0146 NR 57 TC 25 Z9 25 U1 0 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 JAN PY 1995 VL 31 IS 1 BP 199 EP 212 DI 10.1029/94WR02230 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA QF693 UT WOS:A1995QF69300019 ER PT B AU KHARAKA, YK THORDSEN, JJ AMBATS, G AF KHARAKA, YK THORDSEN, JJ AMBATS, G BE Kharaka, YK Chudaev, OV TI Environmental degradation associated with exploration for and production of energy sources in USA SO WATER-ROCK INTERACTION LA English DT Proceedings Paper CT 8th International Symposium on Water-Rock Interaction (WRI-8) CY AUG 15-19, 1995 CL VLADIVOSTOK, RUSSIA SP Int Assoc Geochem & Cosmochem, Russian Acad Sci, Far E Geol Inst, Brit Geol Survey, US Geol Survey C1 US GEOL SURVEY,MENLO PK,CA 94025. 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 90-5410-549-6 PY 1995 BP 25 EP 30 PG 6 WC Geosciences, Multidisciplinary SC Geology GA BD94A UT WOS:A1995BD94A00005 ER PT B AU WHITE, AF BLUM, AE AF WHITE, AF BLUM, AE BE Kharaka, YK Chudaev, OV TI Effects of climate on chemical weathering in watersheds SO WATER-ROCK INTERACTION LA English DT Proceedings Paper CT 8th International Symposium on Water-Rock Interaction (WRI-8) CY AUG 15-19, 1995 CL VLADIVOSTOK, RUSSIA SP Int Assoc Geochem & Cosmochem, Russian Acad Sci, Far E Geol Inst, Brit Geol Survey, US Geol Survey C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 6 U2 11 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-549-6 PY 1995 BP 57 EP 60 PG 4 WC Geosciences, Multidisciplinary SC Geology GA BD94A UT WOS:A1995BD94A00012 ER PT B AU EVANS, WC KLING, GW TUTTLE, ML AF EVANS, WC KLING, GW TUTTLE, ML BE Kharaka, YK Chudaev, OV TI Lake Nyos, Cameroon: Examining the 1986 gas release from the system standpoint SO WATER-ROCK INTERACTION LA English DT Proceedings Paper CT 8th International Symposium on Water-Rock Interaction (WRI-8) CY AUG 15-19, 1995 CL VLADIVOSTOK, RUSSIA SP Int Assoc Geochem & Cosmochem, Russian Acad Sci, Far E Geol Inst, Brit Geol Survey, US Geol Survey C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 1 U2 2 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-549-6 PY 1995 BP 303 EP 306 PG 4 WC Geosciences, Multidisciplinary SC Geology GA BD94A UT WOS:A1995BD94A00069 ER PT B AU CALLENDER, E GRANINA, L AF CALLENDER, E GRANINA, L BE Kharaka, YK Chudaev, OV TI Biogeochemical silica mass balance in Lake Baikal, Russia SO WATER-ROCK INTERACTION LA English DT Proceedings Paper CT 8th International Symposium on Water-Rock Interaction (WRI-8) CY AUG 15-19, 1995 CL VLADIVOSTOK, RUSSIA SP Int Assoc Geochem & Cosmochem, Russian Acad Sci, Far E Geol Inst, Brit Geol Survey, US Geol Survey C1 US GEOL SURVEY,RESTON,VA 22092. 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 90-5410-549-6 PY 1995 BP 341 EP 344 PG 4 WC Geosciences, Multidisciplinary SC Geology GA BD94A UT WOS:A1995BD94A00078 ER PT B AU Wahl, KL Weiss, LS AF Wahl, KL Weiss, LS BE Ward, TJ TI Channel degradation in southeastern Nebraska rivers SO WATERSHED MANAGEMENT: PLANNING FOR THE 21ST CENTURY LA English DT Proceedings Paper CT Symposium on Watershed Management - Planning For the 21st-Century CY AUG 14-16, 1995 CL SAN ANTONIO, TX SP Amer Soc Civil Engineers, Water Resources Engn Div, Watershed Management Co, mm, Amer Soc Civil Engineers, Amer Soc Agr Engineers, USDI Bur Reclamat, Soc Range Management, Soc Amer Foresters, USDA Nat Resources Conservat Serv, Soil & Water Conservat Soc, Natl Council Paper Ind Air & Stream Improvement Inc, US EPA C1 US GEOL SURVEY,LAKEWOOD,CO 80225. NR 0 TC 0 Z9 0 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 0-7844-0102-0 PY 1995 BP 250 EP 259 PG 10 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA BF52R UT WOS:A1995BF52R00026 ER PT J AU Schmidt, PR AF Schmidt, PR GP AMER WIND ENERGY ASSOC TI Wind energy and the migratory bird treaty act SO WINDPOWER '95 - ANNUAL CONFERENCE AND EXHIBITION OF THE AMERICAN WIND ENERGY ASSOCIATION LA English DT Proceedings Paper CT 25th Annual Conference of the American-Wind-Energy-Association (WINDPOWER 95) CY MAR 26-30, 1995 CL WASHINGTON, DC SP Amer Wind Energy Assoc, US DOE, Natl Renewable Energy Lab, Edison Elect Inst C1 US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,WASHINGTON,DC 20240. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN WIND ENERGY ASSOCIATION PI WASHINGTON PA 122 C STREET NW 4TH FLOOR, WASHINGTON, DC 20001-2109 PY 1995 BP 87 EP 92 PG 6 WC Energy & Fuels SC Energy & Fuels GA BF92C UT WOS:A1995BF92C00013 ER PT J AU VAKARCS, G VAIL, PR TARI, G POGACSAS, G MATTICK, RE SZABO, A AF VAKARCS, G VAIL, PR TARI, G POGACSAS, G MATTICK, RE SZABO, A TI 3RD-ORDER MIDDLE MIOCENE EARLY PLIOCENE DEPOSITIONAL SEQUENCES IN THE PROGRADING DELTA-COMPLEX OF THE PANNONIAN BASIN SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT 3rd Annual Workshop of the International-Lithosphere-Program-Task-Force on Origin of Sedimentary Basins CY AUG 18-23, 1992 CL SUNDVOLLEN, NORWAY SP INT LITHOSPHERE PROGRAM TASK FORCE ID EXTENSION; REGION AB Few studies exist in the geologic literature that show the distribution of seismic facies and depositional sequences within a lacustrine basin. The Pannonian Basin of Central Europe offers a unique opportunity to evaluate the influence of the eustatic signal on lacustrine deposition. Seismic stratigraphic and sedimentological studies indicate that the Middle Miocene-Early Pliocene infill of the transtensional Pannonian Basin was formed by large delta systems. Systematic sequence stratigraphic analysis of 6000 km of reflection seismic data and more than 100 hydrocarbon exploration wells in Hungary allowed the identification of twelve third-order sequence boundaries in the late Neogene sedimentary fill. This number of depositional sequences corresponds to that of the published global eustatic curve for this time period. Furthermore, based on magnetostratigraphic and radiometric data, the ages of these depositional sequences can be tentatively correlated with the global eustatic curve. The Pannonian Basin became isolated from the world sea at the Sarmatian/Pannonian (11.5 Ma) boundary and formed a large lake. The stratal patterns and sedimentary facies of individual systems tracts within the lacustrine sequences display the same characteristics as marine depositional sequences. The relatively low rate of thermal subsidence and the high rate of sediment supply resulted in a good sequence resolution. Within the third-order sequences higher-order sequences can be recognized with an average duration of about 0.1-0.5 Ma. C1 MOL RT EXPLORAT DEPT,H-1039 BUDAPEST,HUNGARY. US GEOL SURVEY,RESTON,VA 22092. RP VAKARCS, G (reprint author), RICE UNIV,DEPT GEOL & GEOPHYS,HOUSTON,TX 77251, USA. NR 81 TC 66 Z9 68 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD DEC 30 PY 1994 VL 240 IS 1-4 BP 81 EP 106 DI 10.1016/0040-1951(94)90265-8 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QD987 UT WOS:A1994QD98700007 ER PT J AU JONES, M AF JONES, M TI PCR PRODUCTS AND CITES SO SCIENCE LA English DT Letter RP JONES, M (reprint author), US FISH & WILDLIFE SERV,WASHINGTON,DC 20240, USA. NR 1 TC 12 Z9 13 U1 0 U2 2 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 23 PY 1994 VL 266 IS 5193 BP 1930 EP 1930 DI 10.1126/science.7801116 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PZ267 UT WOS:A1994PZ26700003 PM 7801116 ER PT J AU LENAT, DR CRAWFORD, JK AF LENAT, DR CRAWFORD, JK TI EFFECTS OF LAND-USE ON WATER-QUALITY AND AQUATIC BIOTA OF 3 NORTH-CAROLINA PIEDMONT STREAMS SO HYDROBIOLOGIA LA English DT Article DE WATER QUALITY; SEDIMENT; NUTRIENTS; NONPOINT SOURCE RUNOFF; URBAN RUNOFF; AGRICULTURAL RUNOFF; BENTHOS; MACROINVERTEBRATES; FISH; NORTH CAROLINA ID FISH COMMUNITIES; INDEX; POLLUTION AB Three streams in the Piedmont ecoregion of North Carolina were studied to evaluate the effect of land use (forested, agricultural, urban) on water quality and aquatic biota. In comparison with the forested stream, there were few changes in water quality at the agricultural and urban streams. Suspended-sediment yield was greatest for the urban catchment and least at the forested catchment. Suspended-sediment concentrations during strom events followed this same pattern, but at low-moderate flows suspended-sediment concentrations were greatest at the agricultural site. Most nutrient concentrations were highest at the agricultural site, and the amount of 'available' dissolved nitrogen was elevated at both the urban and agricultural sites. High concentrations of metals (totals) in the water column were sometimes observed at all sites, but maximum average concentrations were recorded at the urban site (especially Cr, Cu, and Pb). Maximum sediment metal concentrations, however, were not found at the urban site, but were usually recorded at the forested site. Only minor differences were noted between fish communities of the forested and agricultural sites, although both abundance and average size of some species increased at the agricultural site. The fish community at the urban site was characterized by low species richness, low biomass, and the absence of intolerant species. Invertebrate taxa richness, a biotic index, and the number of unique invertebrate species (found at only one site) indicated moderate stress (Fair water quality) at the agricultural site and severe stress (Poor water quality) at the urban site. At the agricultural site, declines in taxa richness within intolerant groups were partially offset by increases within tolerant groups. The agricultural stream had the highest abundance values, indicating enrichment. The urban site, however, was characterized by low species richness for most groups and very low abundance values. Analysis of seasonal patterns suggested detritus was the most important food source for invertebrates in the forested stream, while periphyton was of greater importance in the agricultural stream. Dominant macroinvertebrate groups shifted from Ephemeroptera at the forested site, to chironomidae at the agricultural site, and Oligochaeta at the urban site. There was little between-site overlap in dominant species (8-17%), indicating that land use strongly influenced the invertebrate community. Chemical and physical parameters measured at the three sites did not seem sufficient to account for all of the observed differences in the invertebrate communities, suggesting some unmeasured toxicity. Biological measurements, especially macroinvertebrates community structure, consistently indicated strong between-site differences in water and habitat quality. C1 US GEOL SURVEY,DIV WATER RESOURCES,LEMOYNE,PA 17043. RP LENAT, DR (reprint author), N CAROLINA DIV ENVIRONM MANAGEMENT,WATER QUAL SECT,4401 REEDY CREEK RD,RALEIGH,NC 27607, USA. NR 46 TC 274 Z9 294 U1 29 U2 164 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD DEC 16 PY 1994 VL 294 IS 3 BP 185 EP 199 DI 10.1007/BF00021291 PG 15 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA QG907 UT WOS:A1994QG90700002 ER PT J AU NOZETTE, S RUSTAN, P PLEASANCE, LP HORAN, DM REGEON, P SHOEMAKER, EM SPUDIS, PD ACTON, CH BAKER, DN BLAMONT, JE BURATTI, BJ CORSON, MP DAVIES, ME DUXBURY, TC ELIASON, EM JAKOSKY, BM KORDAS, JF LEWIS, IT LICHTENBERG, CL LUCEY, PG MALARET, E MASSIE, MA RESNICK, JH ROLLINS, CJ PARK, HS MCEWEN, AS PRIEST, RE PIETERS, CM REISSE, RA ROBINSON, MS SIMPSON, RA SMITH, DE SORENSON, TC BREUGGE, RWV ZUBER, MT AF NOZETTE, S RUSTAN, P PLEASANCE, LP HORAN, DM REGEON, P SHOEMAKER, EM SPUDIS, PD ACTON, CH BAKER, DN BLAMONT, JE BURATTI, BJ CORSON, MP DAVIES, ME DUXBURY, TC ELIASON, EM JAKOSKY, BM KORDAS, JF LEWIS, IT LICHTENBERG, CL LUCEY, PG MALARET, E MASSIE, MA RESNICK, JH ROLLINS, CJ PARK, HS MCEWEN, AS PRIEST, RE PIETERS, CM REISSE, RA ROBINSON, MS SIMPSON, RA SMITH, DE SORENSON, TC BREUGGE, RWV ZUBER, MT TI THE CLEMENTINE MISSION TO THE MOON - SCIENTIFIC OVERVIEW SO SCIENCE LA English DT Article ID THERMAL EMISSION; COHERENT BACKSCATTER; SURFACE AB In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. USN,RES LAB,WASHINGTON,DC 20375. US GEOL SURVEY,FLAGSTAFF,AZ 86001. LUNAR & PLANETARY INST,HOUSTON,TX 77058. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV COLORADO,LASP,BOULDER,CO 80309. CTR NATL ETUD SPATIALES,PARIS,FRANCE. RES SUPPORT INSTRUMENTS,ALEXANDRIA,VA 22314. RAND CORP,SANTA MONICA,CA 90407. UNIV HAWAII MANOA,HONOLULU,HI 96822. APPL COHERENT TECHNOL,HERNDON,VA 22070. PACIFIC ADV TECHNOL,SOLVANG,CA 94550. BROWN UNIV,PROVIDENCE,RI 02912. SCI INQUIRIES,CATONSVILLE,MD 21228. STANFORD UNIV,STANFORD,CA 94305. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. ALLIED SIGNAL AEROSP CO,ALEXANDRIA,VA 22314. SCI APPLICAT INT CORP,WASHINGTON,DC 20024. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RP NOZETTE, S (reprint author), BALLIST MISSILE DEF ORG,WASHINGTON,DC, USA. NR 23 TC 253 Z9 263 U1 4 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 16 PY 1994 VL 266 IS 5192 BP 1835 EP 1839 DI 10.1126/science.266.5192.1835 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PX383 UT WOS:A1994PX38300028 PM 17737076 ER PT J AU SHOEMAKER, EM ROBINSON, MS ELIASON, EM AF SHOEMAKER, EM ROBINSON, MS ELIASON, EM TI SOUTH-POLE REGION OF THE MOON AS SEEN BY CLEMENTINE SO SCIENCE LA English DT Article ID DEPOSITS AB The Clementine mission has provided the first comprehensive set of high-resolution images of the south pole region of the moon. Within 5 degrees of latitude of the pole, an area of an estimated 30,000 square kilometers remained in shadow during a full lunar rotation and is a promising target for future exploration for ice deposits. The Schrodinger Basin (320 kilometers in diameter), centered at 75 degrees S, is one of the two youngest, least modified, great multiring impact basins on the moon. A large maar-type volcano localized along a graben within the Schrodinger Basin probably erupted between 1 and 2 billion years ago. C1 LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP SHOEMAKER, EM (reprint author), US GEOL SURVEY,FLAGSTAFF,AZ 86001, USA. NR 22 TC 58 Z9 59 U1 1 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 16 PY 1994 VL 266 IS 5192 BP 1851 EP 1854 DI 10.1126/science.266.5192.1851 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PX383 UT WOS:A1994PX38300032 PM 17737080 ER PT J AU MCEWEN, AS ROBINSON, MS ELIASON, EM LUCEY, PG DUXBURY, TC SPUDIS, PD AF MCEWEN, AS ROBINSON, MS ELIASON, EM LUCEY, PG DUXBURY, TC SPUDIS, PD TI CLEMENTINE OBSERVATIONS OF THE ARISTARCHUS REGION OF THE MOON SO SCIENCE LA English DT Article ID LUNAR; SPECTROSCOPY; REFLECTANCE; DEPOSITS AB Multispectral and topographic data acquired by the Clementine spacecraft provide information on the composition and geologic history of the Aristarchus region of the moon. Altimetry profiles show;the Aristarchus plateau dipping about 1 degrees to the north-northwest and rising about 2 kilometers above the surrounding lavas of Oceanus Procellarum to the south. Dark, reddish pyroclastic glass covers the plateau to average depths of 10 to 30 meters, as determined from the estimated excavation depths of 100- to 1000-meter-diameter craters that have exposed materials below the pyroclastics. These craters and the walls of sinuous rilles also show that mare basalts underlie the pyroclastics across much of the plateau. Near-infrared images of Aristarchus crater reveal olivine-rich materials and two kilometer-sized outcrops of anorthosite in the central peaks. The anorthosite could be either a derivative of local magnesium-suite magmatism or a remnant of the ferroan anorthosite crust that formed over the primordial magma ocean. C1 UNIV HAWAII MANOA,DIV PLANETARY GEOSCI,HONOLULU,HI 96822. CALTECH,JET PROP LAB,PASADENA,CA 91109. LUNAR & PLANETARY INST,HOUSTON,TX 77058. RP MCEWEN, AS (reprint author), US GEOL SURVEY,FLAGSTAFF,AZ 86001, USA. NR 33 TC 63 Z9 69 U1 3 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 16 PY 1994 VL 266 IS 5192 BP 1858 EP 1862 DI 10.1126/science.266.5192.1858 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PX383 UT WOS:A1994PX38300034 PM 17737082 ER PT J AU SOMMERFELD, RA BALES, RC MAST, A AF SOMMERFELD, RA BALES, RC MAST, A TI SPATIAL STATISTICS OF SNOWMELT FLOW - DATA FROM LYSIMETERS AND AERIAL PHOTOS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The two-dimensional, horizontal spatial statistics of meltwater flow through a Wyoming snowpack were investigated using two independent methods: meltwater flow from arrays of closely spaced lysimeters and a survey of snow surface brightness on aerial photos. Both methods suggested a characteristic distance of about 6 m over which the respective phenomena were correlated. If a characteristic distance for meltwater flow could be related to snow characteristics such as slope and aspect, modeling of meltwater related phenomena would be facilitated. If the aerial photo data could be shown to be related to the flow data, as these results suggest, a convenient technique for determining meltwater spatial statistics from aerial photos would be available. C1 UNIV ARIZONA,TUCSON,AZ. US GEOL SURVEY,DENVER,CO 80225. RP SOMMERFELD, RA (reprint author), US FOREST SERV,240 W PROSPECT,FT COLLINS,CO 80521, USA. NR 13 TC 9 Z9 9 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 DEC 15 PY 1994 VL 21 IS 25 BP 2821 EP 2824 DI 10.1029/94GL02493 PG 4 WC Geosciences, Multidisciplinary SC Geology GA QA222 UT WOS:A1994QA22200012 ER PT J AU GERLACH, TM MCGEE, KA AF GERLACH, TM MCGEE, KA TI TOTAL SULFUR-DIOXIDE EMISSIONS AND PREERUPTION VAPOR-SATURATED MAGMA AT MOUNT-ST-HELENS, 1980-88 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CARBON-DIOXIDE; DYNAMICS AB SO2 from explosive volcanism can cause significant climatic and atmospheric impacts, but the source of the sulfur is controversial. TOMS, COSPEC, and ash leachate data for Mount St. Helens from the time of the climactic eruption on 18 May 1980 to the final stages of non-explosive degassing in 1988 give a total SO2 emission of 2 Mt. COSPEC data show a sharp drop in emission rate that was apparently controlled by a decreasing rate of magma supply. A total SO2 emission of only 0.08 Mt is estimated from melt inclusion data and the conventional assumption that the main sulfur source was pre-eruption melt; commonly invoked sources of ''excess sulfur'' (anhydrite decomposition, basaltic magma, and degassing of non-erupted magma) are unlikely in this case. Thus melt inclusions may significantly underestimate SO2 emissions and impacts of explosive volcanism on climate and the atmosphere. Measured CO2 emissions, together with the H2O content of melt inclusions and experimental solubility data, indicate the Mount St. Helens dacite was vapor-saturated at depth prior to ascent and suggest that a vapor phase was the main source of sulfur for the 2-Mt of SO2. A vapor source is consistent with experimental studies on the Mount St. Helens dacite and removes the need for a much debated shallow magma body. RP GERLACH, TM (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 24 TC 51 Z9 51 U1 4 U2 11 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 1994 VL 21 IS 25 BP 2833 EP 2836 DI 10.1029/94GL02761 PG 4 WC Geosciences, Multidisciplinary SC Geology GA QA222 UT WOS:A1994QA22200015 ER PT J AU BARNETT, DE BOWMAN, JR PAVLIS, TL RUBENSTONE, JR SNEE, LW ONSTOTT, TC AF BARNETT, DE BOWMAN, JR PAVLIS, TL RUBENSTONE, JR SNEE, LW ONSTOTT, TC TI METAMORPHISM AND NEAR-TRENCH PLUTONISM DURING INITIAL ACCRETION OF THE CRETACEOUS ALASKAN FORE-ARC SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BORDER RANGES FAULT; SOUTHERN ALASKA; CHUGACH MOUNTAINS; SHEAR ZONES; TERTIARY TECTONICS; PHASE-EQUILIBRIA; CATALINA SCHIST; MAFIC SCHIST; ISLAND-ARC; 10 KB AB Cenozoic uplift of the eastern Aleutian forearc has exposed the tectonic join between the Jurassic crystalline hanging wall of the are and the oceanic assemblages of the footwall accreted during Cretaceous and Tertiary subduction, the Border Ranges fault system (BRFS). The early stages of accretion along the BRFS in the Knik River area were characterized by high-temperature ductile thrusting and metamorphism at low to moderate P/T (P from 300-700 MPa, T-max about 600 degrees C). Peak metamorphic conditions at the currently exposed levels can be explained by heat carried to the area by tonalite and trondhjemite plutons. Generation of tonalite and trondhjemite melts within the Cretaceous forearc, however, requires a heat source within or near the BRFS. Ridge subduction cannot be ruled out as the heat source; however, simple thermal models presented herein indicate that the temperatures required for anatexis within the forearc can be explained by transient heating on the fault by shear heating of dry lithologies during the earliest stages of thrust motion. Water released from subducted oceanic crust would result in generation of partial melts in the hanging wall if shear heating is significant or if the initial thermal gradient within the hanging wall is high. Further accretion of oceanic sediment would quench the system and temperatures rapidly evolve to the high P/T conditions of normal subduction zones. Thermochronologic data from this study show that the duration of high- T - low P/T conditions was short, of the order of about 15 m.y. or less. Exhumed forearcs here and elsewhere commonly record a period of low to moderate P/T conditions during subduction initiation in which shear heating likely played an important role. C1 PRINCETON UNIV, DEPT GEOL & GEOPHYS SCI, PRINCETON, NJ 08544 USA. UNIV NEW ORLEANS, DEPT GEOL & GEOPHYS, NEW ORLEANS, LA 70148 USA. LAMONT DOHERTY EARTH OBSERV, PALISADES, NY 10964 USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RP BARNETT, DE (reprint author), UNIV UTAH, DEPT GEOL & GEOPHYS, SALT LAKE CITY, UT 84112 USA. NR 64 TC 14 Z9 14 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 DEC 10 PY 1994 VL 99 IS B12 BP 24007 EP 24024 DI 10.1029/94JB02462 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800016 ER PT J AU HERREROBERVERA, E HELSLEY, CE SARNAWOJCICKI, AM LAJOIE, KR MEYER, CE MCWILLIAMS, MO NEGRINI, RM TURRIN, BD DONNELLYNOLAN, JM LIDDICOAT, JC AF HERREROBERVERA, E HELSLEY, CE SARNAWOJCICKI, AM LAJOIE, KR MEYER, CE MCWILLIAMS, MO NEGRINI, RM TURRIN, BD DONNELLYNOLAN, JM LIDDICOAT, JC TI AGE AND CORRELATION OF A PALEOMAGNETIC EPISODE IN THE WESTERN UNITED-STATES BY AR-40/AR-39 DATING AND TEPHROCHRONOLOGY - THE JAMAICA, BLAKE, OR A NEW POLARITY EPISODE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GEOMAGNETIC-FIELD BEHAVIOR; SUMMER-LAKE; NORTHERN CALIFORNIA; TRANSITION GEOMETRY; TEPHRA LAYERS; SEDIMENTS; REVERSAL; OREGON; NEVADA; BRUNHES AB High-resolution paleomagnetic records from two sites near Pringle Falls, Oregon, are compared with similar records from Summer Lake, Oregon, similar to 170 km to the southeast: Paoha Island, in Mono Lake, similar to 660 km to the southeast and Benton Crossing, in Long Valley, approximately 700 km to the southeast, in east-central California. The sequences at Pringle Falls contain a distinctive coarse pumice-lapilli tephra layer which we have dated as 218+/-10 ka by Ar-40/Ar-39 step-heating of plagioclase feldspar. Stratigraphically, this tephra is closely associated with a suite of several other tephra layers that bracket the interval studied paleomagnetically. Each tephra layer is distinguished by the unique chemical composition of its volcanic glass shards. The pumice layer dated at Pringle Falls is correlated with layers at three of the other localities. Using all the tephra layers, we can correlate the lake stratigraphic sequences and associated paleomagnetic records among the four distant localities. Additional age control is obtained from a fifth locality at Tulelake in northern California, where the stratigraphic interval of interest is bracketed between similar to 171+/-43 and approximately 140 ka. Characteristics of the paleomagnetic records indicate virtually identical paleofield variation, particularly the geometry of a normal to normal (N-N) geomagnetic polarity episode. The observed paleofield behavior resembles the Blake geomagnetic polarity episode, but is significantly older than the generally accepted age of the Blake episode. Either the age of the Blake episode is significantly underestimated, or the polarity episode documented here is older, perhaps the Jamaica episode, or is an as yet unreported episode. A corollary of the latter option is that paleomagnetic polarity episodes of different ages may have similar transition polar paths, a conclusion implying that a common mechanism is involved. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. UNIV HAWAII MANOA, DEPT GEOL & GEOPHYS, HONOLULU, HI 96822 USA. COLUMBIA UNIV BARNARD COLL, DEPT ENVIRONM SCI, NEW YORK, NY 10027 USA. STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. CALIF STATE UNIV, DEPT PHYS & GEOL, BAKERSFIELD, CA 93311 USA. RP HERREROBERVERA, E (reprint author), UNIV HAWAII MANOA, HAWAII INST GEOPHYS & PLANETOL, 2525 CORREA RD, HONOLULU, HI 96822 USA. RI McWilliams, Michael/A-9548-2011 OI McWilliams, Michael/0000-0002-4107-7069 NR 49 TC 62 Z9 63 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 DEC 10 PY 1994 VL 99 IS B12 BP 24091 EP 24103 DI 10.1029/94JB01546 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800021 ER PT J AU NEGRINI, RM ERBES, DB ROBERTS, AP VEROSUB, KL SARNAWOJCICKI, AM MEYER, CE AF NEGRINI, RM ERBES, DB ROBERTS, AP VEROSUB, KL SARNAWOJCICKI, AM MEYER, CE TI REPEATING WAVE-FORM INITIATED BY A 180-190-KA GEOMAGNETIC EXCURSION IN WESTERN NORTH-AMERICA - IMPLICATIONS FOR FIELD BEHAVIOR DURING POLARITY TRANSITIONS AND SUBSEQUENT SECULAR VARIATION SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SUMMER-LAKE; PALEOMAGNETIC EVIDENCE; PLEISTOCENE SEDIMENTS; GREAT-BASIN; LAVA FLOWS; OREGON; RECORD; USA; PALEOINTENSITY; CALIFORNIA AB New paleomagnetic, lithologic, and stratigraphic data are presented from the sediments of Lake Chewaucan in the Summer Lake Basin, Oregon. The new data place better age constraints on the sediments and improve the accuracy of the previously published paleomagnetic record from this locality. A complex, yet distinct, waveform is observed in all three components of the paleomagnetic vector. The waveform begins as the 180-190 ka Pringle Falls/Long Valley/Summer Lake II geomagnetic excursion and continues for two cycles after the excursion, until the record is interrupted by an unconformity that we correlate to the oxygen isotope stage 6/5e boundary. The waveform's directional morphology in virtual geomagnetic pole (VGP) space is defined by two clockwise loops followed by a distinctive counterclockwise, clockwise, counterclockwise looping sequence. The VGP paths of the two cycles after the excursion are rotated 180 degrees about Earth's spin axis with respect to the VGP paths of the excursion cycle. The waveform also consists of a relative paleointensity variation which repeats during the two cycles after the excursion. The average paleointensity of the postexcursion waveform repetitions is high relative to the extremely low values that occur during the excursion. This observation indicates that excursion-initiated secular variations can occur after the field fully recovers from the low intensities which commonly typify excursions. Because of the similarities noted previously between this excursion and full polarity transitions (Tric et al., 1991), our new observations constrain models for a wide range of field behavior including polarity transitions, excursions, and secular variation. C1 UNIV CALIF DAVIS, DEPT GEOL, DAVIS, CA 92616 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP NEGRINI, RM (reprint author), CALIF STATE UNIV, DEPT PHYS & GEOL, BAKERSFIELD, CA 93311 USA. RI Roberts, Andrew/E-6422-2010 OI Roberts, Andrew/0000-0003-0566-8117 NR 33 TC 25 Z9 25 U1 1 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 DEC 10 PY 1994 VL 99 IS B12 BP 24105 EP 24119 DI 10.1029/94JB01544 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800022 ER PT J AU EITTREIM, SL AF EITTREIM, SL TI TRANSITION FROM CONTINENTAL TO OCEANIC-CRUST ON THE WILKES-ADELIE MARGIN OF ANTARCTICA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DEEP SEISMIC-REFLECTION; SOUTHEASTERN AUSTRALIA; CAROLINA TROUGH; PASSIVE MARGIN; EASTERN CANADA; RIFTED MARGIN; SUBSIDENCE; BREAKUP; STRATIGRAPHY; EVOLUTION AB The Wilkes-Adelie margin of East Antarctica, a passive margin rifted in the Early Cretaceous, has an unusually reflective Moho which can be traced seismically across the continent-ocean transition. Velocity models and depth sections were constructed from a combined set of U.S, and French multichannel seismic reflection lines to investigate the transition from continental to oceanic crust, These data show that the boundary between oldest oceanic crust and transitional continental crust is marked by a minimum in subsediment crustal thickness and, in places, by a shoaling of Moho. The Moho reflection is continuous across the edge of oceanic crust, and gradually deepens landward under the continental edge. A marginal rift basin, some tens of kilometers in width, lies in the transition between continental and oceanic crust, contains an average of about 4 km of synrift sediment that is prograded in places, and has characteristics of a former rift valley, now subsided to about 10 km. Three types of reflections in the seismic data are interpreted as volcanic deposits: (1) high-amplitude reflections that floor the marginal rift basin, (2) irregularly seaward dipping sequences that comprise an anomalously thick edge of oceanic crust, and (3) highly irregular and diffractive reflections from oceanic crustal basalts that cap a normal-thickness ocean crust. The present depth to the prerift surface of continental crust is compatible with passive margin subsidence since 95 Ma, corrected for its load of synrift and postrift sediment and mechanically stretched by factors of beta = 1.8 or higher. Comparison of seismic crustal thickness measurements with inferred crustal thinning from subsidence analysis shows agreement for areas where beta < 4. In areas where beta > 4, measured thickness is greater than that inferred from subsidence analysis, a result that could be explained by underplating the crust beneath the marginal rift basin. RP EITTREIM, SL (reprint author), US GEOL SURVEY, MS 999, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 48 TC 18 Z9 19 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 DEC 10 PY 1994 VL 99 IS B12 BP 24189 EP 24205 DI 10.1029/94JB01903 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800027 ER PT J AU VERNIK, L HICKMAN, S LOCKNER, D RUSANOV, M AF VERNIK, L HICKMAN, S LOCKNER, D RUSANOV, M TI ULTRASONIC VELOCITIES IN CORES FROM THE KOLA SUPERDEEP WELL AND THE NATURE OF SUBHORIZONTAL SEISMIC REFLECTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CRACKS; CRUST AB P wave velocity and orthogonally polarized S wave velocities were measured on 12 cores recovered from the Kola superdeep well at depths of 0 to 12 km. Measurements were made along the core axis at a frequency of 1 MHz, at confining pressures ranging from 2 to 100 MPa, and under dry and water-saturated conditions. Cores were chosen to sample a variety of lithologies and were used to estimate interval velocities based on a simplified geological column of the well. These interval velocities were then compared with sonic log and vertical seismic profile (VSP) data. High-pressure lab velocities correlated primarily with rock composition and texture. These laboratory velocities are generally in good agreement with both sonic log and VSP data, suggesting that extremely low velocities, as measured in unconfined laboratory samples or at low confining pressure, are the result of drilling and core-recovery-induced damage. The magnitude of this microcrack-induced damage generally increases with depth in a stepwise manner but with a few notable inversions. These inversions are characterized by a relatively small reduction in dry unconfined velocities compared to the in situ velocities. We interpret these inversions to be due to localized in situ stress relief related to faulting, fracturing, and/or hydrothermal alteration. We also observed pronounced S wave splitting in the cores, the analysis of which suggests that the stress relief microcracks tend to be aligned parallel to the foliation in gneisses and amphibolites (dip angle 28 degrees-45 degrees) rather then being subhorizontal. These observations have important implications for the nature of gently dipping seismic reflections detected in the immediate vicinity of the Kola well. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. NEDRA ENTERPRISE, ZAPOLYARNYI 184415, RUSSIA. RP VERNIK, L (reprint author), STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. NR 33 TC 9 Z9 10 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 1994 VL 99 IS B12 BP 24209 EP 24219 DI 10.1029/94JB01236 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PX338 UT WOS:A1994PX33800029 ER PT J AU GRIFFITH, MB PERRY, SA AF GRIFFITH, MB PERRY, SA TI FUNGAL BIOMASS AND LEAF-LITTER PROCESSING IN STREAMS OF DIFFERENT WATER CHEMISTRY SO HYDROBIOLOGIA LA English DT Article DE LEAF LITTER DECOMPOSITION; STREAMS; WATER CHEMISTRY; PH; ERGOSTEROL; MICROBIAL COMMUNITIES; AQUATIC HYPHOMYCETES ID SOUTHWESTERN PENNSYLVANIA; COMMUNITY STRUCTURE; WOODLAND STREAM; LEAVES; PH; ACIDIFICATION; DECOMPOSITION; ECOSYSTEMS; DYNAMICS; GROWTH AB Leaf litter processing rates and fungal biomass on leaf detritus were compared in four streams of different water chemistry. The streams drained catchments underlain by different bedrock types and varied in mean pH from 4.3 to 7.5 and in mean alkalinity from 0.0 to 35.8 mg CaCO3 1(-1). Processing rates were fastest in WS3 and WS4, which had a pH of 6.0; slowest in SFR, which had a pH of 4.3; and intermediate in HSR which had a pH of 7.5. Fungal biomass as measured by the fungal sterol, ergosterol, was similar in WS3, WS4, and HSR but was much lower in SFR. These results suggest that reduced processing rates in SFR were associated in part with reduced fungal biomass on the leaves, whereas reduced processing rates in HSR were not related to differences in fungal biomass on the leaves. C1 W VIRGINIA UNIV,US FISH & WILDLIFE SERV,MORGANTOWN,WV 26506. NR 55 TC 25 Z9 25 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD DEC 2 PY 1994 VL 294 IS 1 BP 51 EP 61 DI 10.1007/BF00017625 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA QG903 UT WOS:A1994QG90300008 ER PT J AU WILLIAMSSTROUD, SC AF WILLIAMSSTROUD, SC TI SOLUTION TO THE PARADOX - RESULTS OF SOME CHEMICAL-EQUILIBRIUM AND MASS-BALANCE CALCULATIONS APPLIED TO THE PARADOX BASIN EVAPORITE DEPOSIT SO AMERICAN JOURNAL OF SCIENCE LA English DT Article ID POTASH EVAPORITES; ORIGIN; BRINES; MODELS AB Magnesium sulfate poor potash deposits such as the Middle Pennsylvanian Paradox Formation of the Hermosa Group have a mineral paragenesis that cannot be explained by equilibrium evaporation of modern seawater. This paragenesis may be developed through the alteration of seawater into a Ca2+-enriched brine as a result of dolomitization of marginal limestones, which leads to precipitation of primary sylvite and non-precipitation of magnesium sulfate minerals. The 33 cycles of salt deposition in the Paradox were the result of sealevel fluctuations which periodically hooded the basin and established open communication with the ocean. After the basin was cut off from seawater inflow as a result of a drop in sealevel, smaller scale layering in the calcium sulfate and halite beds resulted from intermittent storm influxes of seawater having an average periodicity of several years. Simple mass balance calculations using relative volumes of halite, anhydrite, and dolomite based on core lithology thicknesses were used to calculate volumes of seawater entering the basin during the individual cycles. The geochemical modeling computer programs EQUIL and PHRQPITZ were used to predict the evolution of the brines after compositional alteration due to dolomitization, brine mixing, and precipitation of solutes. The results of the modeling indicate that with reasonable volumes of inflow from different sources, it is possible to develop a brine composition that will produce the mineral assemblage found In the Paradox Formation as a primary paragenesis. RP WILLIAMSSTROUD, SC (reprint author), US GEOL SURVEY,BOX 25046,MS 939,DENVER,CO 80225, USA. NR 83 TC 11 Z9 11 U1 0 U2 2 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520 SN 0002-9599 J9 AM J SCI JI Am. J. Sci. PD DEC PY 1994 VL 294 IS 10 BP 1189 EP 1228 PG 40 WC Geosciences, Multidisciplinary SC Geology GA PV826 UT WOS:A1994PV82600001 ER PT J AU SEIBERT, SG PELTON, MR AF SEIBERT, SG PELTON, MR TI NUTRIENT CONTENT OF SQUAWROOT, CONOPHOLIS-AMERICANA, AND ITS IMPORTANCE TO SOUTHERN APPALACHIAN BLACK BEARS, URSUS-AMERICANUS (CARNIVORA, URSIDAE) SO BRIMLEYANA LA English DT Article AB Squawroot (Conopholis americana), a preferred late spring and early summer food of black bears (Ursus americanus), was collected from Pisgah National Forest, North Carolina, on a weekly basis from 25 April to 4 July 1987. Proximate analysis procedures were used to determine the nutrient content of the plant. Samples were examined for nutrient differences between the capsule and stems. Peak percentages were 13% crude protein (capsule), 31% crude fiber (capsule), 3% fat [either extract] (capsule), and 77% nitrogen-free extract [NFE] (whole plant). Gross energy averaged 4.84 kcal/dry g. Levels of crude protein, crude fiber, and either extract were similar to values reported for soft mast species eaten by bears, and NFE was greater than herbaceous material consumed in spring. Trends in protein and fat content were higher in the capsules; protein decreased as crude fiber increased. Nitrogen-flee extract levels were relatively high throughout the study and likely represent an important energy source for bears feeding on squawroot. C1 US FISH & WILDLIFE SERV, JACKSONVILLE, FL 32216 USA. UNIV TENNESSEE, DEPT FORESTRY WILDLIFE & FISHERIES, KNOXVILLE, TN 37901 USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU NORTH CAROLINA STATE MUSEUM NATURAL SCIENCES PI RALEIGH PA C/O DIRECTOR OF RESEARCH, PO BOX 29555, RALEIGH, NC 27626-0555 USA SN 0193-4406 J9 BRIMLEYANA JI Brimleyana PD DEC PY 1994 IS 21 BP 151 EP 156 PG 6 WC Zoology SC Zoology GA QV987 UT WOS:A1994QV98700015 ER PT J AU HARTZELL, S LANGER, C MENDOZA, C AF HARTZELL, S LANGER, C MENDOZA, C TI RUPTURE HISTORIES OF EASTERN NORTH-AMERICAN EARTHQUAKES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID STRONG GROUND MOTION; 25 NOVEMBER 1988; HARD-ROCK SITES; NAHANNI EARTHQUAKES; SOURCE PARAMETERS; SOURCE SPECTRA; NEW-BRUNSWICK; FINITE FAULT; SHEAR-WAVES; P-WAVE AB Digital, worldwide records of P and SH waves are used to invert for rupture histories of the recent, larger, eastern North American earthquakes. The data include a broad bandwidth to facilitate recovery of both source details and total moment. The following events are studied- 9 January 1982 New Brunswick; 5 October and 23 December 1985 Nahanni; 25 November 1988 Saguenay; and 25 December 1989 Ungava earthquakes. We employ a finite-fault, waveform inversion scheme that discretizes the slip history as a function of position on the fault. This formulation allows estimation of rise time and slip velocity, in addition to the spatial distribution of slip. Static stress drops averaged over the entire rupture surface range from a few tens of bars to just over 100 bars and are similar to values estimated for western United States earthquakes. Estimates of stress drop for spatially limited asperities are in the range of a few hundred bars, with the value for the Saguenay earthquake asperity being the largest (approaching 1 kbar). The variation in stress drop is considerable, but no evidence is seen for a scaling relation in which stress drop increases with moment. Maximum slip velocities on the fault also have a wide range (from 50 cm/sec to perhaps greater then 200 cm/sec), with the Saguenay and 5 October Nahanni earthquakes lying at the upper end of this range. Of the events studied, the Saguenay earthquake is unique in terms of its greater depth, spatially concentrated source, and large asperity stress drop. C1 US GEOL SURVEY,NATL EARTHQUAKE INFORMAT CTR,DENVER,CO 80225. RP HARTZELL, S (reprint author), US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,DENVER,CO 80225, USA. NR 52 TC 26 Z9 28 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 DEC PY 1994 VL 84 IS 6 BP 1703 EP 1724 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QA097 UT WOS:A1994QA09700001 ER PT J AU MARGHERITI, L WENNERBERG, L BOATWRIGHT, J AF MARGHERITI, L WENNERBERG, L BOATWRIGHT, J TI A COMPARISON OF CODA AND S-WAVE SPECTRAL RATIOS AS ESTIMATES OF SITE RESPONSE IN THE SOUTHERN SAN-FRANCISCO BAY AREA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LOMA-PRIETA AFTERSHOCKS; STRONG GROUND MOTION; PROPAGATION CHARACTERISTICS; AMPLIFICATION FACTORS; CENTRAL CALIFORNIA; SOURCE PARAMETERS; LOCAL GEOLOGY; EARTHQUAKE; VALLEY; SEISMOGRAMS AB We calculate spectral ratios for S waves and codas to evaluate the amplification of 14 sites in the southern San Francisco Bay area relative to a nearby bedrock site in the Coyote Hills. Our data are seismograms written by Loma Prieta aftershocks: the epicentral distances and azimuths to the stations are effectively the same. All the sites in the study are amplified with respect to the reference site at frequencies from 0.5 to 7 Hz. The shapes of the S-wave and coda spectral ratios are similar, but the coda ratios are greater than the S-wave ratios by as much as a factor of 4. The difference is larger for sites on alluvial and bay mud deposits, particularly at frequencies around 1 Hz, suggesting the presence of waves trapped in the alluvial basin. In general, the length of the analysis window affects the S-wave spectral ratios for alluvial sites. Longer windows give ratios similar to coda ratios, apparently because these windows include more of the phases that contribute to the coda. We classify the sites according to their geological characteristics and surficial shear-wave velocities. For the S-wave ratios, the differences between the classes showed no systematic trend; the softest and hardest soil classes we consider have practically identical S-wave amplifications. The average coda ratios for the site classes clearly increase as the soil classes include slower and ''softer'' materials. After correction for differences in reference sites, the coda amplifications are very similar to the relative amplifications for these site classes estimated by Borcherdt and Glassmoyer (1992) from the strong-motion recordings of the 1989 Loma Prieta earthquake. RP MARGHERITI, L (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. RI Margheriti, Lucia/C-7082-2008 OI Margheriti, Lucia/0000-0003-3853-254X NR 49 TC 31 Z9 33 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 DEC PY 1994 VL 84 IS 6 BP 1815 EP 1830 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QA097 UT WOS:A1994QA09700008 ER PT J AU NORRIS, RD AF NORRIS, RD TI SEISMICITY OF ROCKFALLS AND AVALANCHES AT 3 CASCADE RANGE VOLCANOS - IMPLICATIONS FOR SEISMIC DETECTION OF HAZARDOUS MASS MOVEMENTS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID MOUNT ST-HELENS; WASHINGTON AB This study reviews seismograms from 14 rockfalls and avalanches of moderate to large volume (10(4) to 10(7) m3) at Mount St. Helens, Mount Adams, and Mount Rainier in the Cascade Range of Washington to investigate how variations in source volume, source materials, track materials, and failure modes affect avalanche seismicity. The largest signals were generated by rockfalls at Mount St. Helens and debris avalanches at Mount Rainier that initiated as block failures. At Mount St. Helens, several rockfalls that originated as block failures near the crater rim descended slopes with similar profiles, and appear to show a linear or nearly linear relation between source volume and seismogram amplitude. Those that fell over an extended period of time were poorly recorded at the reference seismic station and did not show this correlation. Multiple seismograms from three of the four instrumentally recorded debris avalanches at Mount Rainier indicate a tendency of unstable slopes there to fail progressively, a pattern that has important implications for the mass-movement hazard at Mount Rainier. Seismic evidence shows that the Little Tahoma rockfall avalanches in December 1963 occurred on 6 December, over a week earlier than previously reported. Mass movements that have been seismically detected span the spectrum of rapid flowage events, from water surges and debris flows to dry rock, debris, ice, and snow avalanches. The success in identifying and in some cases locating these events in near real time demonstrates that local and regional seismic networks can play a valuable role in reducing hazards from large, rapid mass movements. RP NORRIS, RD (reprint author), UNIV WASHINGTON,US GEOL SURVEY,SEATTLE,WA 98195, USA. NR 22 TC 44 Z9 44 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 DEC PY 1994 VL 84 IS 6 BP 1925 EP 1939 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QA097 UT WOS:A1994QA09700017 ER PT J AU DELANEY, PT MCTIGUE, DF AF DELANEY, PT MCTIGUE, DF TI VOLUME OF MAGMA ACCUMULATION OR WITHDRAWAL ESTIMATED FROM SURFACE UPLIFT OR SUBSIDENCE, WITH APPLICATION TO THE 1960 COLLAPSE OF KILAUEA VOLCANO SO BULLETIN OF VOLCANOLOGY LA English DT Article DE MOGI; DISLOCATIONS; DEFORMATION; KILAUEA AB An elastic point source model proposed by Mogi for magma chamber inflation and deflation has been applied to geodetic data collected at many volcanoes. The volume of ground surface uplift or subsidence estimated from this model is closely related to the volume of magma injection into or withdrawal from the reservoir below. The analytical expressions for these volumes are reviewed for a spherical chamber and it is shown that they differ by the factor 2(1 - nu), where nu is Poisson's ratio of the host rock. For the common estimate nu = 0.25, as used by Mogi and subsequent workers, the uplift volume is 3/2 the injection volume. For highly fractured rocks, nu can be even less and the uplift volume can approach twice the injection volume. Unfortunately, there is no single relation between the inflation of magma reservoirs and the dilation or contraction of host rocks. The inflation of sill-like bodies, for instance, generates no overall change in host rock volume. Inflation of dike-like bodies generates contraction such that, in contrast with Mogi's result, the uplift volume is generally less than the injection volume; for nu = 0.25, the former is only 3/4 of the latter. Estimates of volumes of magma injection or withdrawal are therefore greatly dependent on the magma reservoir configuration. Ground surface tilt data collected during the 1960 collapse of Kilauea crater, one of the first events interpreted with Mogi's model and one of the largest collapses measured at Kilauea, is not favored by any one of a variety of deformation models. These models, however, predict substantially different volumes of both magma withdrawal and ground surface subsidence. RP DELANEY, PT (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 0 TC 70 Z9 70 U1 0 U2 8 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 1994 VL 56 IS 6-7 BP 417 EP 424 DI 10.1007/BF00302823 PG 8 WC Geosciences, Multidisciplinary SC Geology GA QA829 UT WOS:A1994QA82900001 ER PT J AU CLAGUE, DA DENLINGER, RP AF CLAGUE, DA DENLINGER, RP TI ROLE OF OLIVINE CUMULATES IN DESTABILIZING THE FLANKS OF HAWAIIAN VOLCANOS SO BULLETIN OF VOLCANOLOGY LA English DT Article DE OLIVINE CUMULATES; HAWAIIAN VOLCANOS LANDSLIDES; CRYSTAL FLOW AB The south flank of Kilauea Volcano is unstable and has the structure of a huge landslide; it is one of at least 17 enormous catastrophic landslides shed from the Hawaiian Islands. Mechanisms previously proposed for movement of the south flank invoke slip of the volcanic pile over seafloor sediments. Slip on a low friction decollement alone cannot explain why the thickest and widest sector of the flank moves more rapidly than the rest, or why this section contains a 300 km(3) aseismic volume above the seismically defined decollement. It is proposed that this aseismic volume, adjacent to the caldera in the direction of flank slip, consists of olivine cumulates that creep outward, pushing the south flank seawards. Average primary Kilauea tholeiitic magma contains about 16.5 wt.% MgO compared with an average 10 wt.% MgO for erupted subaerial and submarine basalts. This difference requires fractionation of 17 wt.% (14 vol.%) olivine phenocrysts that accumulate near the base of the magma reservoir where they form cumulates. Submarine-erupted Kilauea lavas contain abundant deformed olivine xenocrysts derived from these cumulates. Deformed dunite formed during the tholeiitic shield stage is also erupted as xenoliths in subsequent alkalic lavas. The deformation structures in olivine xenocrysts suggest that the cumulus olivine was densely packed, probably with as little as 5-10 vol.% intercumulus liquid, before entrainment of the xenocrysts. The olivine cumulates were at magmatic temperatures (>1100 degrees C) when the xenocrysts were entrained. Olivine at 1100 degrees C has a theology similar to ice, and the olivine cumulates should flow down and away from the summit of the volcano. Flow of the olivine cumulates places constant pressure on the unbuttressed seaward flank, leading to an extensional region that localizes deep intrusions behind the flank; these intrusions add to the seaward push. This mechanism ties the source of gravitational instability to the caldera complex and deep rift systems and, therefore, limits catastrophic sector failure of Hawaiian volcanoes to their active growth phase, when the core of olivine cumulates is still hot enough to flow. RP CLAGUE, DA (reprint author), US GEOL SURVEY,POB 51,HAWAII NATL PK,HI 96718, USA. NR 0 TC 115 Z9 115 U1 1 U2 11 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 1994 VL 56 IS 6-7 BP 425 EP 434 DI 10.1007/BF00302824 PG 10 WC Geosciences, Multidisciplinary SC Geology GA QA829 UT WOS:A1994QA82900002 ER PT J AU MCGEE, KA SUTTON, AJ AF MCGEE, KA SUTTON, AJ TI ERUPTIVE ACTIVITY AT MOUNT-ST-HELENS, WASHINGTON, USA, 1984-1988 - A GAS GEOCHEMISTRY PERSPECTIVE SO BULLETIN OF VOLCANOLOGY LA English DT Article DE MOUNT ST HELENS; GAS; COSPEC SULFUR DIOXIDE; IN SITU MONITORING; REDUCING GAS AB The results from two different types of gas measurement, telemetered in situ monitoring of reducing gases on the dome and airborne measurements of sulfur dioxide emission rates in the plume by correlation spectrometry, suggest that the combination of these two methods is particularly effective in detecting periods of enhanced degassing that intermittently punctuate the normal background leakage of gaseous effluent from Mount St Helens to the atmosphere. Gas events were recorded before lava extrusion for each of the four dome-building episodes at Mount St Helens since mid-1984. For two of the episodes, precursory reducing gas peaks were detected, whereas during three of the episodes, COSPEC measurements recorded pre cursory degassing of sulfur dioxide. During one episode (October 1986), both reducing gas monitoring and SO2 emission rate measurements simultaneously detected a large gas release several hours before lava extrusion. Had both types of gas measurements been operational during each of the dome-building episodes, it is thought that both would have recorded precursory signals for all four episodes. Evidence from the data presented herein suggests that increased degassing at Mount St Helens becomes detectable when fresh upward-moving magma is between 2 km and a few hundred meters below the base of the dome and between about 60 and 12 hours before the surface extrusion of lava. RP MCGEE, KA (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 0 TC 13 Z9 13 U1 0 U2 3 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 1994 VL 56 IS 6-7 BP 435 EP 446 DI 10.1007/BF00302825 PG 12 WC Geosciences, Multidisciplinary SC Geology GA QA829 UT WOS:A1994QA82900003 ER PT J AU FOORD, EE BROWNFIELD, ME LICHTE, FE DAVIS, AM SUTLEY, SJ AF FOORD, EE BROWNFIELD, ME LICHTE, FE DAVIS, AM SUTLEY, SJ TI MCCRILLISITE, NACS(BE,LI)ZR-2(PO4)(4)CENTER-DOT-1-2H2O, A NEW MINERAL SPECIES FROM MOUNT-MICA, OXFORD COUNTY, MAINE, AND NEW DATA FOR GAINESITE SO CANADIAN MINERALOGIST LA English DT Article DE MCCRILLISITE; NEW MINERAL SPECIES; NA, CS, BE, ZR PHOSPHATE,; GAINESITE; GRANITIC PEGMATITE; MOUNT MICA; OXFORD COUNTY; MAINE ID ZIRCONIUM AB Mccrillisite, ideally NaCs(Be,Li)Zr-2(PO4)(4).1-2H(2)O, a member of the gainesite group, occurs in the Mount Mica granitic pegmatite, South Paris, Oxford County, Maine. The mineral is a product of rate-stage hydrothermal alteration and is associated with approximately twenty other silicate, oxide, carbonate, arsenide and phosphate minerals. Crystals occur in mm- to cm-sized cavities, and individuals are up to 1.2 mm in maximum dimension. The crystals are white to colorless, bipyramidal, with {111} dominant and {001} minor. Streak is white, and luster, vitreous; the mineral is translucent to transparent, and nonfluorescent. Hardness (Mohs) is 4 to 41/2%. No cleavage was observed, and the fracture is conchoidal. D-measured 3.125(5), D-calculated 3.30 g/cm(3). Mccrillisite is uniaxial positive, with omega 1.634(2) and epsilon 1.645(2), colorless and nonpleochroic. The mineral is tetragonal, I4(I)/amd, with a 6.573(2), c 17.28(2) Angstrom V 746.6(9) Angstrom(3), c/a 2.6289, Z = 2. The strongest six reflections in the X-ray powder-diffraction pattern [d(Angstrom)(I)(hkl)] are: 6.159(90)(101), 4.326(80)(004), 4.099(40)(112), 3.281(80)(200), 3.060(100)(105) and 2.896(30)(211). Chemical compositions (wt%) for mccrillisite and cotype gainesite, respectively, are: Li2O 0.6, 0.8; Al2O3 <0.1, 0.5; CaO <0.1, 0.7; MgO 0.1, 0.35; MnO <0.1, 0.7; FeO <0.1, 1.0; SrO 0.2, --; Na2O 4.2, 7.8; K2O 0.3, 2.4; Cs2O 15.3, 2.2; BeO 2.9, 2.3; ZnO 0.5, <0.1; ZrO2 31.6, 33.0; HfO2, 2.5, 0.7; P2O5 38.3, 45.0; Rb2O <0.1, 0.1; F 0.5, <0.1; H2O 3.0, 4.3; subtotal 100.10, 101.95; O = F 0.21, --; total 99.89, 101.95. An empirical formula for mccrillisite, based on 4 P atoms, is: Na-1.00(Cs0.80Li0.18K0.05)(Sigma 1.03) (Be0.86Li0.12Mg0.02)(Sigma 1.00)(Zr1.90Hf0.09Zn0.05)(Sigma 2.04)(P4.00Si0.01)(Sigma 4.01) (O15.8F0.2)(Sigma 16.0).1.23H(2)O. The empirical formula for gainesite, based on 4 P atoms, is: Na-1.00(Na0.59K0.32Cs0.10Rb0.01)(Sigma 1.02) (Be0.58Li0.34Mg0.06Al0.06)(Sigma 10.4)(Zr1.69Fe0.09Ca0.08Mn0.06Hf0.02)(Sigma 1.94)(P4.00Si0.01)(Sigma 4.01)O-15.6.1.5H(2)O. Gainesite was originally considered to be anhydrous, but is shown to contain essential molecular water, as does mccrillisite. The mineral name honors the McCrillis family, particularly the late Dean McCrillis and Philip McCrillis, of Oxford County, Maine, and their more than 90 years spent working the granitic pegmatites of Maine. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. RP FOORD, EE (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 905,BOX 25046,DENVER,CO 80225, USA. NR 7 TC 9 Z9 9 U1 0 U2 0 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD DEC PY 1994 VL 32 BP 839 EP 842 PN 4 PG 4 WC Mineralogy SC Mineralogy GA QD994 UT WOS:A1994QD99400008 ER PT J AU ROBIE, RA SEAL, RR HEMINGWAY, BS AF ROBIE, RA SEAL, RR HEMINGWAY, BS TI HEAT-CAPACITY AND ENTROPY OF BORNITE (CU5FES4) BETWEEN 6-K AND 760-K AND THE THERMODYNAMIC PROPERTIES OF PHASES IN THE SYSTEM CU-FE-S SO CANADIAN MINERALOGIST LA English DT Article DE THERMODYNAMIC PROPERTIES; ENTROPY; GIBBS FREE ENERGY; HEAT CAPACITY; BORNITE; CHALCOPYRITE; CHALCOCITE; NUKUNDAMITE; ANILITE; COVELLITE ID COPPER SULFIDES; HYDROTHERMAL CONDITIONS; STANDARD; 5-K; CALORIMETRY; ENTHALPY AB Heat capacities of synthetic bornite (Cu5FeS4) have been measured by quasi-adiabatic calorimetry between 5 and 351 K and between 338 and 761 K by differential scanning calorimetry. The heat capacity of bornite exhibits a lambda-type anomaly at 65 +/- 1 K associated with the antiferromagnetic ordering of the spins of the Fe3+ ions. Between 140 and 255 K, there is a broad hump in C-p(o) which, in our opinion, may be caused by charge transfer involving Fe2+ - Fe3+ and Cu+ - Cu2+. At 470 +/- 2 and 535 +/- 2 K there are sharp peaks in the heat capacity caused by ordering of the copper, iron and vacancies and the consequent crystallographic changes. At 298.15 K, the heat capacity and entropy of bornite are 242.9 +/- 0.6 and 398.5 +/- 1.0 J.mol(-1) K-1 respectively. Enthalpies and Gibbs free energies of formation of chalcopyrite and bornite are evaluated based on heat capacities (5 to 760 K) and the entropy for bornite, published calorimetric (Delta(f)H degrees and C-p(o)) data for chalcopyrite, thermodynamic data for pyrite, and sulfur fugacity data for the reaction: 5CuFeS(2) + S-2 = Cu5FeS4 + 4FeS(2). Previous studies show that all phases in this reaction are stoichiometric within analytical uncertainty from 673 to 773 K. Therefore, no adjustments for solid-solution effects are needed. Revised expressions for the Gibbs free energy of formation for selected phases in the system Cu-Fe-S are presented below relative to the elements and ideal S-2 gas. [GRAPHICS] ICS] C1 US GEOL SURVEY,RESTON,VA 22092. NR 59 TC 13 Z9 13 U1 0 U2 11 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD DEC PY 1994 VL 32 BP 945 EP 956 PN 4 PG 12 WC Mineralogy SC Mineralogy GA QD994 UT WOS:A1994QD99400019 ER PT J AU KING, G OPPENHEIMER, D AMELUNG, F AF KING, G OPPENHEIMER, D AMELUNG, F TI BLOCK VERSUS CONTINUUM DEFORMATION IN THE WESTERN UNITED-STATES SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID LOMA-PRIETA EARTHQUAKE; ACTIVE DEFORMATION; CONTINENTAL DEFORMATION; SOUTHERN-CALIFORNIA; CRUSTAL DEFORMATION; RUPTURE HISTORY; PLATE MOTIONS; STRAIN RATES; MODEL; SLIP AB The relative role of block versus continuum deformation of continental lithosphere is a current subject of debate. Continuous deformation is suggested by distributed seismicity at continental plate margins and by cumulative seismic moment sums which yield slip estimates that are less than estimates from plate motion studies. In contrast, block models are favored by geologic studies of displacement in places like Asia. A problem in this debate is a lack of data from which unequivocal conclusions may be reached. In this paper we apply the techniques of study used in regions such as the Alpine-Himalayan belt to an area with a wealth of instrumental data-the Western United States. By comparing plate rates to seismic moment release rates and assuming a typical seismogenic layer thickness of 15 km it appears that since 1850 about 60% of the Pacific-North America motion across the plate boundary in California and Nevada has occurred seismically and 40% aseismically. The San Francisco Bay area shows similar partitioning between seismic and aseismic deformation, and it can be shown that within the seismogenic depth range aseismic deformation is concentrated near the surface and at depth. In some cases this deformation can be located on creeping surface faults, but elsewhere it is spread over a several kilometer wide zone adjacent to the fault. These superficial creeping deformation zones may be responsible for the palaeomagnetic rotations that have been ascribed elsewhere to the surface expression of continuum deformation in the lithosphere. Our results support the dominant role of non-continuum deformation processes with the implication that deformation localization by strain softening must occur in the lower crust and probably the upper mantle. Our conclusions apply only to the regions where the data are good, and even within the Western United States (i.e., the Basin-and Range) deformation styles remain poorly resolved. Nonetheless, we maintain that block motion is the deformation style of choice for those continental regions where the data are best. C1 US GEOL SURVEY, MENLO PK, CA USA. RP KING, G (reprint author), INST PHYS GLOBE STRASBOURG, 5 RUE RENE DESCARTES, F-67084 STRASBOURG, FRANCE. RI Amelung, Falk/J-9042-2012; OI Oppenheimer, David/0000-0002-6569-3640 NR 59 TC 49 Z9 50 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 DEC PY 1994 VL 128 IS 3-4 BP 55 EP 64 DI 10.1016/0012-821X(94)90134-1 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QC238 UT WOS:A1994QC23800001 ER PT J AU LINK, WA KARANTH, KU AF LINK, WA KARANTH, KU TI CORRECTING FOR OVERDISPERSION IN TESTS OF PREY SELECTIVITY SO ECOLOGY LA English DT Note ID PREDATION C1 NEW YORK ZOOL SOC,WILDLIFE CONSERVAT SOC,BRONX,NY 10460. RP LINK, WA (reprint author), US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708, USA. NR 6 TC 16 Z9 18 U1 0 U2 4 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD DEC PY 1994 VL 75 IS 8 BP 2456 EP 2459 DI 10.2307/1940899 PG 4 WC Ecology SC Environmental Sciences & Ecology GA PW554 UT WOS:A1994PW55400026 ER PT J AU ELSTON, WE PLUMLEE, GS AF ELSTON, WE PLUMLEE, GS TI A SPECIAL ISSUE ON VOLCANIC CENTERS AS TARGETS FOR MINERAL EXPLORATION - PREFACE SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Editorial Material C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP ELSTON, WE (reprint author), UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,ALBUQUERQUE,NM 87131, USA. NR 0 TC 1 Z9 1 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 1994 VL 89 IS 8 BP 1661 EP 1661 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300001 ER PT J AU RYTUBA, JJ AF RYTUBA, JJ TI EVOLUTION OF VOLCANIC AND TECTONIC FEATURES IN CALDERA SETTINGS AND THEIR IMPORTANCE IN THE LOCALIZATION OF ORE-DEPOSITS SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID NEVADA; COMPLEX; MOUNTAIN AB Many calderas are located along regionally important fault zones that are intermittently active before and after the caldera cycle. In mineralized calderas, the ore deposits are controlled by structures developed during caldera formation and by regional faults which intersect and reactivate the caldera-related structures. In the earliest phase of the caldera cycle, tumescence occurs over the shallowly emplaced magma chamber and normal faults develop within the structural dome above the magma chamber. This early phase of faulting is disrupted by caldera formation but some of the faults are preserved outside the caldera margin and may become important ore-controlling structures such as the Ruja mercury deposit in the McDermitt caldera complex, Nevada, and the precious metal deposits in the Atlanta district, Nevada, outside the Indian Peak caldera. Caldera-related structures such as ring fracture faults are commonly the most important in controlling the emplacement of resurgent magma, as well as postcollapse intrusions and associated ore deposits. During the resurgence phase of the caldera, faults related to an apical graben, and radial and ring faults and fractures form and may extend outside the collapse structure. Radial and ring faults and fractures provided the structural control for gold alunite-type deposits in the Rodalquilar caldera complex, Spain. At the end of the caldera cycle, the area over the batholith related to the caldera-forming magma chambers is uplifted as isostatic compensation occurs, or subsides if the volcanic field is developed within a rapidly subsiding graben. Volume change resulting from crystallization will also contribute to subsidence. Regional subsidence of the Lake Owyhee volcanic field in southeastern Oregon at the end of the caldera cycle is reflected by arkosic sedimentation in the caldera basins and throughout the eastern part of the volcanic field. Crystallization of the underlying batholith permits the reestablishment of brittle deformation along the regional faults which initially may have controlled magma emplacement. This tectonic activity may reactivate caldera structures and these typically become important for localization of hydrothermal activity. Hot spring-type gold deposits in the Lake Owyhee volcanic field formed when a regional northwest-trending structure reactivated the caldera ring fracture fault zone of the Three Fingers caldera. The formation of hydrothermal ore deposits at the end of the caldera cycle is often related to tectonic reactivation of caldera structures by regional faults and emplacement of small volumes of magma as stocks and vent complexes along these structures. RP RYTUBA, JJ (reprint author), US GEOL SURVEY,MAIL STOP 901,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 26 TC 26 Z9 27 U1 0 U2 6 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 1994 VL 89 IS 8 BP 1687 EP 1696 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300003 ER PT J AU LARSON, PB CUNNINGHAM, CG NAESER, CW AF LARSON, PB CUNNINGHAM, CG NAESER, CW TI LARGE-SCALE ALTERATION EFFECTS IN THE RICO PALEOTHERMAL ANOMALY, SOUTHWEST COLORADO SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID HYDROTHERMAL SYSTEMS; ORE DEPOSITION; OXYGEN ISOTOPE; GEOCHEMISTRY; O-18/O-16 AB A major 4 Ma paleothermal anomaly is present around the Silver Creek stockwork Mo deposit near Rico, southwestern Colorado. The anomaly extends at least 8 km outward from the deposit and was formed from heated, meteoric water circulating around an intrusion related to the deposit. The top of the 4 Ma Mo deposit is located near the center of the anomaly, more than 1 km beneath the present ground surface. Near-surface contemperaneous vein and replacement base and precious metal deposits are peripheral to the Mo system; they were the source of historic production in the Rico mining district. The thermal and chemical effects of the paleothermal anomaly are well developed in 65 Ma hornblende latite sills that extend throughout the district. They provided an essentially uniform material in which to measure the effects of water-rock interaction. Hydrothermal alteration in the latite resulted in several alteration facies. A texturally destructive facies proximal to the center of the system consists of quartz-illite-calcite and chlorite-epidote assemblages and is restricted to a vertical cylindrical zone, 3 km in diameter, directly above the stockwork Mo deposit. Peripheral to this, the latite is altered to a propylitic assemblage, with primary textures preserved. Temperature gradients in the altered latite, measured from tetrahedral-site Al in hydrothermal chlorite and the degree of partial annealing of fission tracks in apatite and zircon, are symmetrically distributed about the stockwork Mo deposit and show that temperature increased gradationally toward the heat source. The chlorite tetrahedral Al geothermometer indicates that temperatures were less than 200 degrees C in the distal part of the system and greater than 300 degrees C in the center of the paleothermal anomaly, directly over the stockwork Mo system. Whole-rock delta(18)O values of the latite decrease from near fresh-rock values of about 9.0 per mil to as low as -4.0 per mil above the Mo deposit. Mass exchange between fluid and latite is extensive above the Mo deposit, where nearly all of the Na2O has been removed from the rocks. The extent and distribution of thermal and chemical effects in a vertical cylindrical volume of rock above the heat source suggests that this marks the pathway for an upwelling geothermal plume, 3 km wide and at least 2 km high. A horizontal outflow plume moved laterally away from the rising plume 1.5 to 2 km above the stockwork Mo system. Water/rock ratios within the plume area are greater than 0.5 on a molar oxygen basis, but are less than 0.45 in the propylitized latite outside the plume. All mineralization in the Rico district is related to this 4 Ma meteoric-magmatic hydrothermal system. The deep stockwork Mo deposit is beneath the plume and the shallower veins and replacement deposits are at the margins of the plume. C1 US GEOL SURVEY,NATL CTR 959,RESTON,VA 22092. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP LARSON, PB (reprint author), WASHINGTON STATE UNIV,DEPT GEOL,PULLMAN,WA 99164, USA. NR 31 TC 6 Z9 6 U1 2 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 1994 VL 89 IS 8 BP 1769 EP 1779 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300007 ER PT J AU CUNNINGHAM, CG APARICIO, H MURILLO, F JIMENEZ, N LIZECA, JL MCKEE, EH ERICKSEN, GE TAVERA, F AF CUNNINGHAM, CG APARICIO, H MURILLO, F JIMENEZ, N LIZECA, JL MCKEE, EH ERICKSEN, GE TAVERA, F TI RELATIONSHIP BETWEEN THE PORCO, BOLIVIA, AG-ZN-PB-SN DEPOSIT AND THE PORCO CALDERA SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SAN-JUAN MOUNTAINS; DISTRICT; COLORADO; MODEL; TIN AB The Porco Ag-Zn-Pb-Sn deposit, a major Ag producer in the 16th century and currently the major Zn producer in Bolivia, consists of a swarm of fissure-filling veins in the newly recognized Porco caldera. The caldera measures 5 km north-south by 3 km east-west and formed in response to the eruption of the 12 Ma crystal-rich dacitic Porco Tuff Well-defined topographic walls of the caldera are cut in Ordovician and Cretaceous sedimentary rocks. The mineralization is associated with, and is probably genetically related to, the 8.6 Ma Huayna Porco stock (elev 4,528 m); the deposit is part of a system of radial dikes, metal zonation, and alteration mineral patterns centered on the stock. The outflow Porco Tuff to the north underlies the 6 to 9 Ma ash-now tuffs of the Los Frailes volcanic field. The Porco deposit consists of steeply dipping irregular and curvilinear veins that cut the intracaldera Porco Tuff about 1 km east of the Huayna Porco stock. Major veins are generally less than a meter wide and as much as 2 km long. Most of the veins, especially the most productive ones, together with a small stock, dike, and breccia pipe, are aligned along the structural margin (ring fracture) of the caldera. The ore deposit is zoned around the Huayna Porco stock-cassiterite is generally close to the stock, and base metals, mostly as sphalerite and galena, are farther away, along the ring fracture veins. The primary Ag minerals, chiefly pyragyrite, acanthite, and stephanite, are most abundant in the upper parts of the veins. Fluid inclusions in sphalerite stalactites have homogenization temperatures of about 225 degrees C and salinities of about 8 wt percent NaCl equiv. The stalactites and the presence of sparse vapor-rich inclusions suggest deposition of sphalerite under boiling conditions. Modeling the depth of formation below the water table indicates that the present ground surface is close to the surface that existed at the time of mineralization. C1 CO MINERA SUR SA,POTOSI,BOLIVIA. SERV GEOL BOLIVIA,LA PAZ,BOLIVIA. US GEOL SURVEY,MENLO PK,CA 94025. RP CUNNINGHAM, CG (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 17 TC 10 Z9 11 U1 0 U2 0 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 1994 VL 89 IS 8 BP 1833 EP 1841 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300010 ER PT J AU FOLEY, NK AYUSO, RA AF FOLEY, NK AYUSO, RA TI LEAD-ISOTOPE COMPOSITIONS AS GUIDES TO EARLY GOLD MINERALIZATION - THE NORTH AMETHYST VEIN SYSTEM, CREEDE DISTRICT, COLORADO SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SAN-JUAN-MOUNTAINS; WESTERN UNITED-STATES; MINING DISTRICT; ORE DEPOSITION; VOLCANIC FIELD; SOUTHWESTERN COLORADO; ROCKS; ENVIRONMENT; PB; EVOLUTION AB The North Amethyst vein system, which is hosted by similar to 27 Ma Carpenter Ridge Tuff and similar to 26 Ma Nelson Mountain Tuff has two mineral associations separated by brecciation and sedimentation in the veins. The early association consists of quartz, rhodonite, hematite, magnetite, electrum (Au0.3-0.5Ag0.7-0.5), and Mn carbonate, Au-Ag sulfide, Ag sulfosalt, and base metal sulfide minerals. The later mineral association cuts the Mn- and Au-bearing assemblages and consists of quartz, calcite, sericite, chlorite, hematite, adularia, fluorite, base metal sulfides, and Ag-bearing tetrahedrite. Our detailed studies show that the Pb isotope compositions of paragenetically early galenas associated with Au-rich mineralization in the North Amethyst vein system are relatively unradiogenic (Pb-206/Pb-204: 18.826-18.881, Pb-207/Pb-204: 15.588-15.602, and Pb-208/Pb-204: 37.790-37.926) compared to Pb isotope compositions of galenas formed later at about 25 Ma during Ag and base metal mineralization (Pb-206/Pb-204: 19.041-19.115, Pb-207/Pb-204: 15.627-15.672, and Pb-208/Pb-204: 37.829-38.057) New Pb isotope data for the central and southern parts of the Creede district, which are located 5 to 7 km south of the North Amethyst area, agree with the results of a regional study by Doe et al. (1979) that included five samples from the main part of the Creede district. Galenas and adularia from the central and southern Creede district and galenas from the Bondholder district, 7 km north of the North Amethyst area, are similar to the Pb isotope compositions of galenas formed later in the North Amethyst area during Ag and base metal mineralization. Galenas from the Alpha-Corsair vein, which was mined for Ag prior to 1910, are isotopically similar to galenas associated with North Amethyst Au-stage mineralization. This isotopic similarity suggests that unexplored segments of the Alpha-Corsair structure may have the same mineralogy as the North Amethyst Au stage; thus, the Alpha-Corsair structure has the potential for high gold contents. Pb isotope compositions from the late stage of the North Amethyst vein system and from the Bondholder and central and southern Creede mining districts are more radiogenic than the host volcanic rocks of the central cluster of the San Juan volcanic field. Our Ph isotope results indicate that early Au mineralization of the North Amethyst area may represent the product of an older and relatively local hydrothermal system distinct from that of the younger base metal and Ag mineralization found throughout the region. Fluids that deposited Au minerals may have derived their Pb isotope composition by a greater degree of interaction with shallow, relatively less radiogenic volcanic wall rocks. The younger, base metal and Ag-rich mineralization that overprints the Au mineralization in the North Amethyst area clearly has a more radiogenic isotopic signature, which implies that the later mineralization derived a greater component of its Pb from Proterozoic source rocks, or sediments derived from them. Paragenetically early sulfide-rich vein assemblages have the least radiogenic galenas and generally also have the highest Au contents. Thus, identification of paragenetically early vein assemblages with relatively unradiogenic Pb isotope compositions similar to those of the North Amethyst area provides an additional exploration tool for Au in the central San Juan Mountains area. RP FOLEY, NK (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 52 TC 9 Z9 11 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 1994 VL 89 IS 8 BP 1842 EP 1859 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300011 ER PT J AU PLUMLEE, GS AF PLUMLEE, GS TI FLUID CHEMISTRY EVOLUTION AND MINERAL DEPOSITION IN THE MAIN-STAGE CREEDE EPITHERMAL SYSTEM SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SAN-JUAN MOUNTAINS; MINING DISTRICT; ORE DEPOSITION; COLORADO; ENVIRONMENT; EQUILIBRIA; INCLUSION; STANDARD; MOLAL; GASES AB This paper presents results of chemical speciation and reaction path calculations that model fluid chemistry evolution and ore deposition in the main-stage Creede, Colorado, epithermal system. An extensive geologic, mineralogic, and geochemical framework for mineralization has been developed by many researchers for the central and southern district vein systems (OH and P veins; central and southern Amethyst and Bulldog Mountain vein systems) and is used to constrain and guide the modeling presented in this paper. Previous studies have shown that the central base metal sulfide-rich and southern barite- and silver-rich Creede ores were deposited by hydrothermal brines with temperatures as high as 285 degrees C and salinities as high as 13 wt percent NaCl equiv. Fluid inclusion studies indicate that mixing with dilute steam-heated ground waters was the dominant ore deposition mechanism, although boiling did occur during some stages. Speciation calculations confirm that the hydrothermal fluids, due to their high salinities, were relatively acidic (pH near 5.5) and transported significant quantities of base metals (i.e., up to 10-2 m total concentrations of Zn) as chloride complexes. Reaction path calculations show that strong north-south mineralogical variations in main-stage mineralization are best accounted for by variable boiling of the hydrothermal brines, followed by lateral mixing of the brines with overlying dilute, steam-heated ground waters. The extent of boiling prior to mixing was a function of the temperature and gas contents of the hydrothermal fluids as they first entered the district ore zones from depth, and of the thickness of the steam-heated ground-water column overlying the hydrothermal fluids. The calculations indicate that limited amounts of boiling (during stages when the overlying ground-water column was relatively thick) produced a chlorite-pyrite-hematite-sphalerite-galena-chalcopyrite +/- adularia assemblage in the central district vein systems (OH and P veins; central Amethyst and Bulldog Mountain vein systems). More extensive boiling (during a stage in which the ground-water table apparently dropped considerably) deposited quartz, fluorite, adularia, and hematite with only minor sulfides in the central district veins. Boiling ceased when the saturation pressure of the hydrothermal fluids dropped below hydrostatic pressures generated by the overlying ground-water column. Following boiling, lateral mixing with overlying steam-heated ground waters initially produced sphalerite- and galena-rich assemblages in the central district vein systems. With continued mixing to the south, the hydrothermal fluids deposited abundant barite, subordinate sphalerite, galena, and quartz, and lesser native silver, acanthite, and sulfosalts in the district's southern vein systems (southern Amethyst, southern Bulldog Mountain vein systems). Modeling results for Creede and other epithermal fluid compositions show that epithermal ore grades, mineral assemblages, and mineral zoning patterns are strongly influenced by shallow hydrologic processes such as boiling and fluid mixing. As a result, epithermal mineral assemblages and zoning patterns can be used to reconstruct the paleohydrology of the hydrothermal systems from which they were deposited, and thus provide useful tools for epithermal ore exploration. RP PLUMLEE, GS (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 973,DENVER,CO 80225, USA. NR 40 TC 18 Z9 20 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 1994 VL 89 IS 8 BP 1860 EP 1882 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300012 ER PT J AU PLUMLEE, GS WHITEHOUSEVEAUX, PH AF PLUMLEE, GS WHITEHOUSEVEAUX, PH TI MINERALOGY, PARAGENESIS, AND MINERAL ZONING OF THE BULLDOG MOUNTAIN VEIN SYSTEM, CREEDE DISTRICT, COLORADO SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SAN-JUAN MOUNTAINS; MINING DISTRICT; ORE DEPOSITION; ENVIRONMENT AB The Bulldog Mountain vein system, Creede district, Colorado, is one of four major epithermal vein systems from which the bulk of the district's historical Ag-Pb-Zn-Cu production has come. Ores deposited along the vein system were discovered in 1965 and were mined from 1969 to 1985. Six temporally gradational mineralization stages have been identified along the Bulldog Mountain vein system, each with a characteristic suite of minerals deposited or leached and a characteristic distribution within the vein system; some of these stages are also strongly zoned within the vein system. Stage A was dominated by deposition of rhodochrosite along the lower levels of the Bulldog Mountain ore zone. Stage B in the northern parts of the ore zone is characterized by abundant fine-grained sphalerite and galena, with lesser tetrahedrite and minor chlorite and hematite. With increasing elevation to the south, stage B ores become progressively more barite and silver rich, with alternating barite and fine-grained sphalerite + galena generations; native silver +/- acanthite assemblages are also locally abundant within southern stage B barite sulfide ores, whereas chalcopyrite and other Cu and Ag sulfides and sulfosalts are present erratically in minor amounts. Stage C in the upper and northern portions of the ore zone is characterized by abundant quartz and fluorite, minor adularia, hematite, Mn siderite, sphalerite, and galena, and major leaching of earlier barite; to the south, some barite and sulfides may have been deposited. Stage D sphalerite and galena were deposited in the upper and northern portions of the ore zone; a barite- and silver-rich facies of this stage may also be present in the southern portions of the vein system. Late in stage D, mineralogically complex assemblages containing chalcopyrite, tetrahedrite, polybasite, bornite, pyrargyrite, and a variety of other sulfides and sulfosalts were deposited in modest amounts throughout the vein system. This complex assemblage marked the transition to stage E. During stage E, the final sulfide stage, abundant botryoidal pyrite and marcasite with lesser stibnite, sphalerite, and sulfosalts were deposited primarily along the top of the Bulldog Mountain ore zone. Stage F, the final mineralization stage along the vein system, is marked by wire silver and concurrent leaching of earlier sulfides and sulfosalts; this stage may reflect the transition to a supergene environment. The sequence of mineralization stages identified in this study along the Bulldog Mountain system can be correlated with corresponding stages identified by other researchers along the OH and P veins, and the southern Amethyst vein system. Mineral zoning patterns identified along the Bulldog Mountain vein system also parallel larger scale zoning patterns across the central and southern Creede district. The complex variations in mineral assemblages documented in time and space along the Bulldog Mountain vein system were produced by the combined effects of many processes. Large-scale changes in vein mineralogy over time produced discrete mineralization stages. Short-term mineralogical fluctuations produced complex interbanding of mineralogically distinct generations. Fluid chemistry evolution within the vein system produced large-scale lateral zoning patterns within certain stages. Hypogene leaching substantially modified the distributions of some minerals. Finally, structural activity, mineral deposition, and mineral leaching modified fluid flow pathways repeatedly during mineralization, and so added to the complex mineral distribution patterns within the vein system. C1 US GEOL SURVEY,RESTON,VA 22092. RP PLUMLEE, GS (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MAIL STOP 973,DENVER,CO 80225, USA. NR 22 TC 9 Z9 9 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 1994 VL 89 IS 8 BP 1883 EP 1905 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300013 ER PT J AU GRAY, JE COOLBAUGH, MF AF GRAY, JE COOLBAUGH, MF TI GEOLOGY AND GEOCHEMISTRY OF SUMMITVILLE, COLORADO - AN EPITHERMAL ACID SULFATE DEPOSIT IN A VOLCANIC DOME SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SAN-JUAN-MOUNTAINS; MINING DISTRICT; MOLYBDENITE DEPOSITS; ORE DEPOSITION; MINERALIZATION; GOLD; ISOTOPE; ENVIRONMENT; EVOLUTION; COUNTY AB Geologic studies during recent open-pit mining at Summitville, Colorado, have provided new information on an epithermal acid sulfate Au Ag-Cu deposit formed in a volcanic dome. Geologic mapping, geochemical studies of whole-rock samples from blast holes, and geologic and geochemical traverse studies refine the details of the evolution of the Summitville deposit. Six distinct events followed emplacement of the quartz latite volcanic dome and define the development of the Summitville deposit: (1) an early stage of acid. sulfate alteration, (2) subsequent Cu sulfide and gold mineralization, (3) widespread hydrothermal brecciation, (4) volumetrically minor, base metal sulfide-bearing barite veining, (5) volumetrically miner, kaolinite matrix brecciation, and finally, (6) supergene oxidation. Events 1 and 2 were the most important for the formation of the Summitville deposit. Acid sulfate altered rock is primarily found in the quartz latite volcanic dome rock and consists of vuggy silica (central), quartz-alunite, quartz-kaolinite, argillic, and propylitic (distal) zones. Ore deposition (Event 2) of enargite, luzonite, covellite, pyrite, native sulfur, marcasite, and minor sphalerite, native gold, +/- barite and galena overprinted the acid sulfate altered rocks. Events 3, 4, and 5 are geologically important but rarely formed units large enough to be considered mineable ore by open-pit mining. The final supergene oxidation event affected much of the near-surface portion of the deposit and leached copper and sulfide minerals forming oxide zones. Nearsurface oxide zones contain the highest Au grades and decrease progressively with depth. Fractures were important for localizing both the acid sulfate altered rock and ore deposition at Summitville. Such fracture control is apparent despite a lack of distinct throughgoing open-space quartz veins; instead, laterally and vertically extensive ore zones are identified by their highly silicified character that can be traced laterally for up to 500 m and vertically up to 200 m. Ore zones strike parallel to regional faults related to rifting and basin and range development, suggesting that hydrothermal fluids followed preexisting fractures. Ore zones follow two northwest trends, a N 30 degrees W +/- 20 degrees trend, and a N 60 degrees W trend. Most fractures and faults in the open pit dip steeply from 65 degrees to vertical. Ore zones intersect near the center of the deposit to form a large zone approximately 150 by 400 m. Ore zones form a rough radial pattern located near the center of the deposit and a discontinuous arcuate feature on the northern side. This radial pattern, arcuate feature, and the intersection of ore zones near the center of the deposit are probably related to the intrusion of a porphyry below the deposit. The overall low Au-grade, high-tonnage character of the Summitville deposit is related to low permeability in the quartz latite volcanic dome rock and absence of well-developed open-space hydrothermal veins. Gold analyses of development drill holes and blast hole samples, in conjunction with geologic mapping in the open pit, indicate that vuggy silica, quartz-alunite, and quartz-kaolinite altered rock constitute most of the Au ore. Vuggy silica averaged 2.4 ppm Au, quartz-alunite averaged 1.2 ppm Au, and quartz-kaolinite averaged 0.86 ppm Au during open-pit mining. Grades for argillically altered rock were usually below the ore cutoff of 0.34 ppm Au. Propylitically altered rock rarely contained detectable Au concentrations (0.03 ppm Au) and constituted only waste rock. Although volumetrically minor, event 1 base metal sulfide-bearing barite veins and event 5 kaolinite matrix breccias contained high An grades (up to about 800 ppm Au), producing approximately 5 to 15 percent of the total Au mined in the deposit. Geochemical studies of samples collected across traverses of altered and mineralized ore zones indicate that Te, Bi, and Pb are characteristic trace elements, in addition to Au, Ag, Cu, and As that are typical of acid sulfate mineral deposits. Anomalous Te is associated with Cu sulfides and gold in vuggy silica zones. Anomalous Bi and Pb concentrations correlate most consistently with quartz-alunite zones. Thallium is also anomalous at Summitville, Highest concentrations of Tl are found in argillic rock, whereas silicified zones are depleted in it. The anomalous Tl in distal zones is similar to observations in some porphyry Cu systems. Pronounced lateral zonation of Ag/Au ratios is present in the deposit. The Ag/Au ratios vary from about 2:1 near the center of the orebody to greater than 20:1 on the periphery. The Summitville deposit is located in the midlevel portion of a mineralized volcanic dome, with a porphyry system at depth, and a hot springs environment at the surface. Drill holes through the volcanic dome intersected a quartz monzonite porphyry approximately 600 m below the surface that is altered to sericite and pyrite similar to some porphyry deposits. Laterally extensive cristobalite and opal replacing quartz latite are found southwest of the deposit and represent a hot-spring environment. Bedded siliceous sinter, some of which contains plant debris, overlies the cristobalite and opal at some localities. These deposits may represent surface vents for the fluids responsible for acid sulfate alteration or mineralization of the volcanic dome. C1 CARSON GOLD CORP,VANCOUVER,BC V6C 2G8,CANADA. RP GRAY, JE (reprint author), US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225, USA. NR 62 TC 18 Z9 20 U1 1 U2 11 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 1994 VL 89 IS 8 BP 1906 EP 1923 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300014 ER PT J AU DEEN, JA RYE, RO MUNOZ, JL DREXLER, JW AF DEEN, JA RYE, RO MUNOZ, JL DREXLER, JW TI THE MAGMATIC HYDROTHERMAL SYSTEM AT JULCANI, PERU - EVIDENCE FROM FLUID INCLUSIONS AND HYDROGEN AND OXYGEN ISOTOPES SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID ACID-SULFATE ALTERATION; MINING DISTRICT; EVOLUTION; DEPOSITS; MINERALIZATION; WOLFRAMITE; COLORADO; GENESIS; QUARTZ; WATER AB The Julcani district consists of at least six mineralized centers in a 16-km(2) late Miocene, dacitic to rhyolitic dome complex that is built on a similar to 3,000-m-thick Paleozoic-Mesozoic elastic sedimentary section. Mineralization occurred within 0.5 m.y. of the youngest dome formation and was prior to emplacement of an anhydrite-bearing dacite dike. Hydrothermal events began with formation of fracture-controlled acid sulfate alteration zones having vuggy silica cores and successive quartz-alunite and quartz-kaolinite envelopes. The acid sulfate alteration in the center of the district was overlapped and followed by the emplacement of radiating swarms of tourmaline-pyrite breccia dikelets cemented by quartz-containing saline fluid inclusions. Several centers of mineralization developed 0.5 to 2 km apart along reactivated regional structures after the emplacement of a dacite dike most likely related to an underlying intrusion. The ores consist of Ag-Cu-Pb-W-Bi-Au-bearing mineral assemblages that occur as fracture fillings within the domes and underlying tuffs. Mineralization reached within 200 to 300 m of the paleosurface. The ores are strongly zoned with a general succession of quartz + pyrite + wolfamite-, enargite-, tetrahedrite-, galena-, and barite-dominant assemblages grading outward east and west from the central zone. Late-stage siderite and/or botryoidal pyrite overprint all zones, even at the deepest levels. Filling temperatures and salinities for inclusion fluids in main-stage minerals range from 250 degrees to 325 degrees C and 8 and 19 wt percent NaCl equiv, respectively. Filling temperatures for inclusions in late-stage siderite range from 170 degrees to 225 degrees C and salinities average about 7.5 wt percent NaCl equiv. Temperatures tend to correlate with salinities and both tend to decrease in the fluids of successively younger and more distal minerals from wolframite to enargite to siderite. The calculated delta D-H2O and delta(18)O(H2O) values of the preore alunite-forming fluids are about -46 +/- 5 and 7 +/- 1 per mil, respectively. The delta D-H2O and delta(18)O(H2O) values of inclusion fluids in later main-stage wolframite, enargite, tetrahedrite, and galena and late-stage siderite show a linear trend, ranging from -60 to -130 and 4 to -18 per mil, respectively. Based on the composition of biotite phenocyrsts in glassy volcanic rocks that bracket ore deposition, primary magmatic fluids had delta D-H2O and delta(18)O(H2O) values of about -70 +/- 20 and 9.7 +/- 0.6 per mil, respectively. The fluids responsible for main-stage mineralization as well as preore acid sulfate and tourmaline breccia fluids were distinctly magmatic. These ore fluids, however, were highly exchanged (similar in isotopic composition to alunite-forming fluids) and were not derived directly from the magma but from the low water-rock environment between the fluid-rich carapace of the magma and the brittle-ductile transition of the overlying rocks. Ore deposition occurred when the exchanged magmatic fluids mixed with meteoric water at higher levels. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP DEEN, JA (reprint author), UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309, USA. NR 42 TC 41 Z9 43 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 DEC PY 1994 VL 89 IS 8 BP 1924 EP 1938 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300015 ER PT J AU CUNNINGHAM, CG STEVEN, TA ROWLEY, PD NAESER, CW MEHNERT, HH HEDGE, CE LUDWIG, KR AF CUNNINGHAM, CG STEVEN, TA ROWLEY, PD NAESER, CW MEHNERT, HH HEDGE, CE LUDWIG, KR TI EVOLUTION OF VOLCANIC-ROCKS AND ASSOCIATED ORE-DEPOSITS IN THE MARYSVALE VOLCANIC FIELD, UTAH SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Note ID WEST-CENTRAL UTAH C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP CUNNINGHAM, CG (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 959,RESTON,VA 22092, USA. NR 13 TC 5 Z9 5 U1 3 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 1994 VL 89 IS 8 BP 2003 EP 2005 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300019 ER PT J AU GRAY, JE COOLBAUGH, MF PLUMLEE, GS ATKINSON, WW AF GRAY, JE COOLBAUGH, MF PLUMLEE, GS ATKINSON, WW TI ENVIRONMENTAL GEOLOGY OF THE SUMMITVILLE MINE, COLORADO SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Note C1 CARSON GOLD CORP,VANCOUVER,BC V6C 2G8,CANADA. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80302. RP GRAY, JE (reprint author), US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225, USA. NR 13 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 1994 VL 89 IS 8 BP 2006 EP 2014 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QK973 UT WOS:A1994QK97300020 ER PT J AU ASQUITH, A KIDO, M AF ASQUITH, A KIDO, M TI NATIVE HAWAIIAN INSECTS ATTRACTED TO THE SEMIOCHEMICAL METHYL EUGENOL, USED FOR MALE ANNIHILATION OF THE ORIENTAL FRUIT-FLY (DIPTERA, TEPHRITIDAE) SO ENVIRONMENTAL ENTOMOLOGY LA English DT Article DE BACTROCERA DORSALIS; DROSOPHILIDAE; NONTARGETS ID SEXUAL SELECTION; DROSOPHILIDAE; ECOLOGY AB This study addressed the potential susceptibility of native Hawaiian insects to the semiochemical methyl eugenol used for male annihilation of the oriental fruit fly, Bactrocera dorsalis (Hendel). The effects of trap type (methyl eugenol, methyl eugenol + toxin, toxin only, and control) and trap height (0, 1, 2, or 4 m above ground) were studied in native forest on the island of Kauai. A malaise trap was used to determine the relative abundance of insects in the immediate vicinity of the methyl eugenol traps. Seven species of native Hawaiian Drosophilidae, two species of Muscidae, and one species of Phoridae were found to be attracted to methyl eugenol. For four other taxa, including species of Miridae, Anobiidae, and Proctotrupidae, attraction to methyl eugenol is suggested but equivocal. For all species except Drosophila villosipedis (Drosophilidae) and Brachyserphus hawaiiensis (Proctotrupidae) both males and females were attracted to methyl eugenol. For Drosophila perissopoda, Drosophila basimacula, Scaptomyza varipicta, and Scaptomyza rostrata, ground level traps caught significantly more individuals than traps above ground, and for all drosophilids, 4-m high traps caught the fewest individuals. Among non-Drosophilidae, trap height was not a significant factor in captures for only the Anobiidae and Sarona species (Miridae). Megaselia sp. (Phoridae) was similar to Scaptomyza tantalia (Drosophilidae) in that almost all individuals were captured in ground level traps. Orthotylus sp. (Miridae) was the only species in which 4-m high traps caught the greatest number of individuals. For Lispocephala species (Muscidae) and B. hawaiiensis, 1-2-m high traps tended to catch more individuals than the ground-level or 4-m high traps. Malaise trap data suggest that methyl eugenol traps either attracted these species roughly in proportion to their local abundance (D. villosipedis, D. basimacula) or they captured only a portion of the local pool of individuals (S. varipicta, D. perissopoda, D. kokeensis, Lispocephala spp.). Because of the low level of attraction displayed by the native insects and the potential to mitigate the impact by placement of baits in the forest canopy, it is suggested that an environmentally acceptable application of methyl eugenol can be devised for use in the Hawaiian Islands. C1 UNIV HAWAII,KAUAI RES STN,KAPAA,HI 96746. RP ASQUITH, A (reprint author), US FISH & WILDLIFE SERV,PACIFIC ISL OFF,3 WATERFRONT PLAZA,500 ALA MOANA BLVD,SUITE 580,HONOLULU,HI 96813, USA. NR 50 TC 10 Z9 12 U1 2 U2 7 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 SN 0046-225X J9 ENVIRON ENTOMOL JI Environ. Entomol. PD DEC PY 1994 VL 23 IS 6 BP 1397 EP 1408 PG 12 WC Entomology SC Entomology GA PZ146 UT WOS:A1994PZ14600005 ER PT J AU EATON, GP AF EATON, GP TI ECOSYSTEMS AND ENVIRONMENTAL EARTH-SCIENCE SO ENVIRONMENTAL GEOLOGY LA English DT Note RP EATON, GP (reprint author), US GEOL SURVEY,OFF DIRECTOR,100 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 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 DEC PY 1994 VL 24 IS 4 BP 309 EP 311 PG 3 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA PY920 UT WOS:A1994PY92000010 ER PT J AU THURMAN, EM MEYER, MT MILLS, MS ZIMMERMAN, LR PERRY, CA GOOLSBY, DA AF THURMAN, EM MEYER, MT MILLS, MS ZIMMERMAN, LR PERRY, CA GOOLSBY, DA TI FORMATION AND TRANSPORT OF DEETHYLATRAZINE AND DEISOPROPYLATRAZINE IN SURFACE-WATER SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; MIDWESTERN UNITED-STATES; BOUND RESIDUE FORMATION; WESTERN TENNESSEE SOIL; CLAY LOAM SOIL; DEGRADATION PRODUCTS; TRIAZINE HERBICIDES; NONPOINT-SOURCE; C-14 ATRAZINE; METABOLITES AB Field disappearance studies and a regional study of nine rivers in the Midwest Corn Belt show that deethylatrazine (DEA; 2-amino-4-chloro-6-isopropylamino-s-triazine) and deisopropylatrazine (DIA; 2-amino-4-chloro-6-ethylamino-s-triazine) occur frequently in surface water that has received runoff from two parent triazine herbicides, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and cyanazine (2-chloro-4-ethylamino-6-methyl-propionitrileamino-s-triazine). The concentration of DEA and DIA in surface water varies with the hydrologic conditions of the basin and the timing of runoff, with maximum concentrations reaching 5 mug/L (DEA + DIA). Early rainfall followed by a dry summer will result in an early peak concentration of metabolities in surface water. A wet summer will delay the maximum concentrations of metabolites and increase their runoff into surface water, occasionally resulting in a slight separation of the parent atrazine maximum concentrations from the metabolite maximum concentrations, giving a ''second flush'' of triazine metabolites to surface water. Replicated field dissipation studies of atrazine and cyanazine indicate that DIA/DEA ratios will vary from 0.4 +/- 0.1 when atrazine is the major triazine present to 0.6 +/- 0.1 when significant amounts of cyanazine are present. A comparison of transport time of DEA and DIA from field plots to their appearance in surface water indicates that storage and dilution are occurring in the alluvial aquifers of the basin. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP THURMAN, EM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. RI Thurman, Earl/B-5131-2011; Zimmerman, Lisa/K-6674-2012; OI Meyer, Michael/0000-0001-6006-7985 NR 40 TC 105 Z9 105 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC PY 1994 VL 28 IS 13 BP 2267 EP 2277 DI 10.1021/es00062a010 PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PV171 UT WOS:A1994PV17100013 PM 22176044 ER PT J AU WANG, WC SQUILLACE, P AF WANG, WC SQUILLACE, P TI HERBICIDE INTERCHANGE BETWEEN A STREAM AND THE ADJACENT ALLUVIAL AQUIFER SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID NONPOINT-SOURCE; SOIL; PESTICIDE; ATRAZINE; MINERALIZATION; RIVER; WATER AB Herbicide interchange between a stream and the adjacent alluvial aquifer and quantification of herbicide bank storage during high streamflow were investigated at a research site on the Cedar River flood plain, 10 km southeast of Cedar Rapids, Iowa. During high streamflow in March 1990, alachlor, atrazine, and metolachlor were detected at concentrations above background in water from wells as distant as 20, 50, and 10 m from the river's edge, respectively. During high streamflow in May 1990, alachlor, atrazine, cyanazine, and metolachlor were detected at concentrations above background as distant as 20, 50, 10, and 20 m from the river's edge, respectively. Herbicide bank storage took place during high streamflow when hydraulic gradients were from the river to the alluvial aquifer and the laterally infiltrating river water contained herbicide concentrations larger than background concentrations in the aquifer. The herbicide bank storage can be quantified by multiplying herbicide concentration by the ''effective area'' that a well represented and an assumed porosity of 0.25. During March 1990, herbicide bank storage values were calculated to be 1.7, 79, and 4.0 mg/m for alachlor, atrazine, and metolachlor, respectively. During May 1990, values were 7.1, 54, 11, and 19 mg/m for alachlor, atrazine, cyanazine, and metolachlor, respectively. C1 US GEOL SURVEY,IOWA CITY,IA 52240. RP WANG, WC (reprint author), US GEOL SURVEY,720 GRACERN RD,SUITE 129,COLUMBIA,SC 29210, USA. NR 25 TC 23 Z9 23 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC PY 1994 VL 28 IS 13 BP 2336 EP 2344 DI 10.1021/es00062a018 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PV171 UT WOS:A1994PV17100021 PM 22176052 ER PT J AU LINDER, G HAZELWOOD, R PALAWSKI, D BOLLMAN, M WILBORN, D MALLOY, J DUBOIS, K OTT, S PASCOE, G DALSOGLIO, J AF LINDER, G HAZELWOOD, R PALAWSKI, D BOLLMAN, M WILBORN, D MALLOY, J DUBOIS, K OTT, S PASCOE, G DALSOGLIO, J TI ECOLOGICAL ASSESSMENT FOR THE WETLANDS AT MILLTOWN RESERVOIR, MISSOULA, MONTANA - CHARACTERIZATION OF EMERGENT AND UPLAND HABITATS SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article; Proceedings Paper CT 13th Annual Meeting of the Society-of-Environmental-Toxicology-and-Chemistry CY NOV 08-12, 1992 CL CINCINNATI, OH SP SOC ENVIRONM TOXICOL & CHEM DE WETLANDS; HEAVY METALS; ARSENIC; SOIL CONTAMINATION; ECOLOGICAL RISK ASSESSMENT AB Wetlands in mining districts in the western United States are frequently impacted by heavy metal-contaminated sediments. The present study summarizes a soil contamination evaluation and an ecological assessment completed for a Superfund site located at Milltown Reservoir wetlands (MRW) in western Montana. For wetlands, as well as upland habitats adjacent to wetlands, biological evaluations in the field and laboratory should be considered critical components in the ecological risk assessment process. Depending upon habitat type, field and laboratory methods have been developed for hazard and risk assessment that lend themselves directly to the Superfund ecological risk assessment process, and that consider contaminant bioavailability and subtle expressions of adverse biological effects associated with chronic exposures. As part of an ecological risk assessment for MRW, field surveys and a variety of biological test methods (e.g., terrestrial and aquatic tests) were critical to the wetland evaluation. For evaluating heavy metal effects at MRW, field and laboratory methods within the ecological assessment included wetlands delineation and preliminary plant and wildlife survey; vegetation tests in emergent and upland habitats; soil macroinvertebrate (earthworm) tests; preliminary studies using amphibian and bacterial test systems; soil characterizations; and chemical analysis of soils, sediments, and biological materials. In conjunction with chemical analyses, these biological and ecological evaluations yielded an integrated evaluation of ecological effects and exposure at MRW. The data gathered from laboratory and field work at MRW suggested that biological and ecological effects were subtle in their expression in the wetland. In conjunction with sediment contamination evaluations, these studies should reduce the uncertainty associated with the baseline ecological risk assessment for MRW. C1 US FISH & WILDLIFE SERV,ECOL SERV,HELENA,MT 59601. MANTECH ENVIRONM RES SERV CORP,CORVALLIS,OR 97333. ENVIRONM TOXICOL INT LTD,SEATTLE,WA 98101. US EPA,HELENA,MT 59626. NR 38 TC 24 Z9 24 U1 1 U2 8 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 DEC PY 1994 VL 13 IS 12 BP 1957 EP 1970 DI 10.1897/1552-8618(1994)13[1957:EAFTWA]2.0.CO;2 PG 14 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA PU902 UT WOS:A1994PU90200010 ER PT J AU PASCOE, GA BLANCHET, RJ LINDER, G PALAWSKI, D BRUMBAUGH, WG CANFIELD, TJ KEMBLE, NE INGERSOLL, CG FARAG, A DALSOGLIO, JA AF PASCOE, GA BLANCHET, RJ LINDER, G PALAWSKI, D BRUMBAUGH, WG CANFIELD, TJ KEMBLE, NE INGERSOLL, CG FARAG, A DALSOGLIO, JA TI CHARACTERIZATION OF ECOLOGICAL RISKS AT THE MILLTOWN RESERVOIR CLARK-FORK RIVER SEDIMENTS SUPERFUND SITE, MONTANA SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE ECOLOGICAL RISK ASSESSMENT; METALS; WETLAND; CLARK FORK RIVER; MINING WASTES ID QUALITY TRIAD; CONTAMINATION; TOXICITY AB A comprehensive field and laboratory approach to the ecological risk assessment for the Milltown Reservoir-Clark Fork River Sediments Site, a Superfund site in the Rocky Mountains of Montana, has been described in the preceding reports of this series. The risk assessment addresses concerns over the ecological impacts of upstream releases of mining wastes to fisheries of the upper Clark Fork River (CFR) and the benthic and terrestrial habitats further downstream in Milltown Reservoir. The risk characterization component of the process integrated results from a triad of information sources: (a) chemistry studies of environmental media to identify and quantify exposures of terrestrial and aquatic organisms to site-related contaminants; (b) ecological or population studies of terrestrial vegetation, birds, benthic communities, and fish; and (c) in situ and laboratory toxicity studies with terrestrial and aquatic invertebrates and plants, smalt mammals, amphibians,and fish exposed to contaminated surface water, sediments, wetland soils, and food sources. Trophic transfer studies were performed on waterfowl, mammals, and predatory birds using field measurement data on metals concentrations in environmental media and lower trophic food sources. Studies with sediment exposures were incorporated into the Sediment Quality Triad approach to evaluate risks to benthic ecology. Overall results of the wetland and terrestrial studies suggested that acute adverse biological effects were largely absent from the wetland; however, adverse effects to reproductive, growth, and physiological end points of various terrestrial and aquatic species were related to metals exposures in more highly contaminated depositional areas. Feeding studies with contaminated diet collected from the upper CFR indicated that trout are at high risk from elevated metals concentrations in surface water, sediment, and aquatic invertebrates. Integration of chemical analyses with toxicological and ecological evaluations of metal effects on the wetland and fishery has provided an important foundation for environmental decisions at this site. C1 MANTECH ENVIRONM TECHNOL INC, CORVALLIS, OR 97333 USA. US FISH & WILDLIFE SERV, HELENA, MT 59601 USA. NATL BIOL SURVEY, NATL FISHERIES CONTAINMENT RES CTR, COLUMBIA, MO 65201 USA. UNIV WYOMING, DEPT ZOOL & PHYSIOL, LARAMIE, WY 82071 USA. US EPA, HELENA, MT 59626 USA. RP PASCOE, GA (reprint author), ENVIRONM TOXICOL INT INC, 600 STEWART ST, SUITE 700, SEATTLE, WA 98101 USA. NR 57 TC 17 Z9 18 U1 3 U2 21 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 DEC PY 1994 VL 13 IS 12 BP 2043 EP 2058 DI 10.1897/1552-8618(1994)13[2043:COERAT]2.0.CO;2 PG 16 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA PU902 UT WOS:A1994PU90200017 ER PT J AU BRETT, R SCHMIDTTHOME, M AF BRETT, R SCHMIDTTHOME, M TI INTERNATIONAL GEOLOGICAL SCIENCE COOPERATION - THE ROLE OF IUG SO EPISODES LA English DT Article; Proceedings Paper CT International Meeting on Geological Science in a Changing Society, on the Occasion of the 125th Anniversary of the Hungarian-Geological-Survey CY SEP, 1994 CL BUDAPEST, HUNGARY SP Hungarian Geol Survey, Int Consortium Geol Survey, Int Union Geol Sci AB Within the earth sciences, governmental and non-governmental structures support international scientific activities. The aim of the International Union of Geological Sciences (IUGS) which has over 100 member countries, includes the encouragement of research on geological problems of fundamental or applied character and the promotion of international interdisciplinary cooperation in geology and related sciences. The IUGS does not perform research, but rather promotes the realisation of activities that otherwise might be impossible or very difficult to organise without an international catalyst. Scientific activities of the IUGS are carried out by its 12 commissions, by international committees or by affiliated organisations-today more than 30-which are autonomous international associations or societies. These numerous scientific bodies constitute a network of tens of thousands of geologists around the world. The main role of IUGS is coordination of activities to minimise duplication of effort and to promote joint ventures so that resources and responsibilities are shared. RP BRETT, R (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT UNION GEOLOGICAL SCIENCES PI HERNDON PA PO BOX 919, HERNDON, VA 22070 SN 0705-3797 J9 EPISODES JI Episodes PD DEC PY 1994 VL 17 IS 4 BP 118 EP 120 PG 3 WC Geosciences, Multidisciplinary SC Geology GA RG030 UT WOS:A1994RG03000008 ER PT J AU BRATKOVICH, A DINNEL, SP GOOLSBY, DA AF BRATKOVICH, A DINNEL, SP GOOLSBY, DA TI VARIABILITY AND PREDICTION OF FRESH-WATER AND NITRATE FLUXES FOR THE LOUISIANA-TEXAS SHELF - MISSISSIPPI AND ATCHAFALAYA RIVER SOURCE FUNCTIONS SO ESTUARIES LA English DT Article ID WATER AB Time histories of riverine water discharge, nitrate concentration, and nitrate flux have been analyzed for the Mississippi and Atchafalaya rivers. Results indicate that water discharge variability is dominated by the annual cycle and shorter-time-scale episodic events presumably associated with snowmelt runoff and spring or summer rains. Interannual variability in water discharge is relatively small compared to the above, In contrast, nitrate concentration exhibits strongest variability at decadal time scales. The interannual variability is not monotonic but more complicated in structure. Weak covariability between water discharge and nitrate concentration leads to a relatively ''noisy'' nitrate flux signal. Nitrate flux variations exhibit a low-amplitude, long-term modulation of a dominant annual cycle. Predictor-hindcastor analyses indicate that skilled forecasts of nitrate concentration and nitrate flux fields are feasible. Water discharge was the most reliably hindcast (on seasonal to interannual time scales) due to the fundamental strength of the annual hydrologic cycle. However, the forecasting effort for this variable was less successful than the hindcasting effort, mostly due to a phase shift in the annual cycle during our relatively short test period (18 mo). Nitrate concentration was more skillfully predicted (seasonal to interannual time scales) due to the relative dominance of the decadal-scale portion of the signal. Nitrate flux was also skillfully forecast even though historical analyses seemed to indicate that it should be more difficult to predict than either water discharge or nitrate concentration. C1 UNIV SO MISSISSIPPI,CTR MARINE SCI,BAY ST LOUIS,MS 39529. US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. RP BRATKOVICH, A (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 22 TC 45 Z9 46 U1 0 U2 2 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1994 VL 17 IS 4 BP 766 EP 778 DI 10.2307/1352746 PG 13 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA QJ256 UT WOS:A1994QJ25600005 ER PT J AU PROMISLOW, D MONTGOMERIE, R MARTIN, TE AF PROMISLOW, D MONTGOMERIE, R MARTIN, TE TI SEXUAL SELECTION AND SURVIVAL IN NORTH-AMERICAN WATERFOWL SO EVOLUTION LA English DT Note DE ANATIDAE; BIRDS; MORTALITY; SEXUAL SELECTION; WATERFOWL ID PHYLOGENETIC ANALYSIS; NATURAL-POPULATIONS; RECOVERY RATES; BODY-WEIGHT; BIRDS; MAMMALS; MORTALITY; DUCKS; PATTERNS; DIMORPHISM C1 QUEENS UNIV,DEPT BIOL,KINGSTON,ON K7L 3N6,CANADA. UNIV ARKANSAS,US FISH & WILDLIFE SERV,ARKANSAS COOPERAT FISH & WILDLIFE RES UNIT,FAYETTEVILLE,AR 72701. RI Montgomerie, Robert/C-6516-2008; Martin, Thomas/F-6016-2011 OI Montgomerie, Robert/0000-0003-4701-4525; Martin, Thomas/0000-0002-4028-4867 NR 46 TC 43 Z9 44 U1 1 U2 9 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD DEC PY 1994 VL 48 IS 6 BP 2045 EP 2050 DI 10.2307/2410526 PG 6 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA RA377 UT WOS:A1994RA37700022 ER PT J AU EDWARDS, G AF EDWARDS, G TI NEW USFWS FISHERIES ACTION PLAN WILL HELP FISH SO FISHERIES LA English DT Editorial Material RP EDWARDS, G (reprint author), US FISH & WILDLIFE SERV,18TH & C ST NW,RM 3245,WASHINGTON,DC 20240, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD DEC PY 1994 VL 19 IS 12 BP 10 EP 11 PG 2 WC Fisheries SC Fisheries GA PV195 UT WOS:A1994PV19500003 ER PT J AU ROMINGER, EM ALLENJOHNSON, L OLDEMEYER, JL AF ROMINGER, EM ALLENJOHNSON, L OLDEMEYER, JL TI ARBOREAL LICHEN IN UNCUT AND PARTIALLY CUT SUB-ALPINE FIR STANDS IN WOODLAND CARIBOU HABITAT, NORTHERN IDAHO AND SOUTHEASTERN BRITISH-COLUMBIA SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE ABIES LASIOCARPA; ALECTORIA SARMENTOSA; BRYORI; FORESTRY MANAGEMENT; RANGIFER TARANDUS CARIBOU; PARTIAL CUTTING ID SELKIRK MOUNTAINS AB To better understand the effects of partial cutting on arboreal lichen biomass production within woodland caribou (Rangifer tarandus caribou) habitat, lichen was hand picked from 1228 branches on 307 subalpine fir (Abies lasiocarpa) trees in Idaho (ID), and in British Columbia (BC). Lichen biomass from partially cut stands was compared with biomass on trees from adjacent uncut stands at each site. Arboreal lichen biomass did not differ significantly between uncut and partially cut stands. Total number of branches per tree did not differ significantly between uncut and partially cut stands. Live branches had more lichen than dead branches. Species composition of arboreal lichen changed in partially cut stands compared with adjacent uncut stands. The ratio of live to dead branches was substantially different within the BC partial cut. C1 US FISH & WILDLIFE SERV,NATL ECOL RES CTR,FT COLLINS,CO 80525. NR 37 TC 24 Z9 26 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD DEC PY 1994 VL 70 IS 1-3 BP 195 EP 202 DI 10.1016/0378-1127(94)90086-8 PG 8 WC Forestry SC Forestry GA QC199 UT WOS:A1994QC19900017 ER PT J AU Karlinger, MR Over, TM Troutman, BM AF Karlinger, M. R. Over, T. M. Troutman, B. M. TI RELATING THIN AND FAT-FRACTAL SCALING OF RIVER-NETWORK MODELS SO FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY LA English DT Article AB The fractal scaling of river networks has been described in the context of both thin and fat fractals. Whereas the thin-fractal characterization is presented as a fractal dimension, D, derived from the length properties of the river channels, a fat-fractal characterization is given as a scaling exponent, beta, derived from the behavior of river-channel area. Several authors have related D to the bifurcation ratio, R(b), and length ratio, R(l), of idealized Hortonian-network trees. Here, for these types of trees, we asymptotically relate beta to R(b), R(l), and to a diameter exponent, Delta, which governs the downstream channel-widening process. Using this result, we present a linkage of D to beta and discuss the implications of the relative values of R(b), R(l), and Delta on this linkage and on network channel behavior. Finally, we illustrate bias in the estimation of beta from preasymptotic trees. C1 [Karlinger, M. R.; Troutman, B. M.] US Geol Survey, WRD, Denver, CO 80225 USA. [Over, T. M.] Univ Colorado, Ctr Study Earth Space CIRES, Boulder, CO 80309 USA. RP Karlinger, MR (reprint author), US Geol Survey, WRD, Box 25046,MS418, Denver, CO 80225 USA. NR 16 TC 6 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-348X J9 FRACTALS JI Fractals-Complex Geom. Patterns Scaling Nat. Soc. PD DEC PY 1994 VL 2 IS 4 BP 557 EP 565 DI 10.1142/S0218348X94000788 PG 9 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA V18XB UT WOS:000208036400011 ER PT J AU FOURNIER, RO KENNEDY, BM AOKI, M THOMPSON, JM AF FOURNIER, RO KENNEDY, BM AOKI, M THOMPSON, JM TI CORRELATION OF GOLD IN SILICEOUS SINTERS WITH HE-3/HE-4 IN HOT-SPRING WATERS OF YELLOWSTONE-NATIONAL-PARK SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HELIUM-ISOTOPES; GEYSER BASIN; TRANSPORT; GEOCHEMISTRY; 25-DEGREES-C; DEPOSITION; EVOLUTION; CHEMISTRY; COMPLEXES; SYSTEMS AB Opaline sinter samples collected at Yellowstone National Park (YNP) were analyzed for gold by neutron activation and for other trace elements by the inductively coupled plasma optical emission spectroscopy (ICP-OES) method. No correlation was found between Au and As, Sb, or total Fe in the sinters, although the sample containing the highest Au also contains the highest Sb. There also was no correlation of Au in the sinter with the H2S concentration in the discharged hot spring water or with the estimated temperature of last equilibration of the water with the surrounding rock. The Au in rhyolitic tuffs and lavas at YNP found within the Yellowstone caldera show the same range in Au as do those outside the caldera, while thermal waters from within this caldera all have been found to contain relatively low dissolved Au and to deposit sinters that contain relatively little Au. Therefore, it is not likely that variations in Au concentrations among these sinters simply reflect differences in leachable Au in the rocks through which the hydrothermal fluids have passed. Rather, variations in [H2S], the concentration of total dissolved sulfide, that result from different physical and chemical processes that occur in different parts of the hydrothermal system appear to exert the main control on the abundance of Au in these sinters. Hydrothermal fluids at YNP convect upward through a series of successively shallower and cooler reservoirs where water-rock chemical and isotopic reactions occur in response to changing temperature and pressure. In some parts of the system the fluids undergo decompressional boiling, and in other parts they cool conductively without boiling. Mixing of ascending water from deep in the system with shallow groundwaters is common. All three processes generally result in a decrease in [H2S] and destabilize dissolved gold bisulfide complexes in reservoir waters in the YNP system. Thus, different reservoirs in rocks of similar composition and at similar temperatures may contain waters with different [H2S] and [AU]. The [H2S] in a subsurface reservoir water is difficult to assess on the basis of analyses of hot spring waters because of uncertainties about steam loss during fluid ascent. However, the same processes that result in low [H2S] in reservoir waters also tend to result in decreases in the ratio of He-3/He-4(R) dissolved in that water. Values of R relative to this ratio in air (Ra) attain values >15 in YNP thermal waters. To date, all of the thermal waters at YNP that have R/Ra values <9 have been found to deposit sinters with relatively low gold concentrations. These include all of the thermal waters that discharge from 180-215 degrees C reservoirs at Upper, Midway, and Lower Geyser Basins within the western part of the Yellowstone caldera. and thermal waters at Norris Geyser Basin, outside the Yellowstone caldera, where some of the waters flow directly to the surface from a reservoir where the temperature is about 300 degrees C. A high He-3/He-4 ratio in thermal water discharged at the surface does not guarantee high gold concentrations in the sinter deposited by this water. Boiling with loss of steam (the gas phase takes a separate route to the surface) during rapid upflow from the shallowest reservoir to the surface decreases the [H2S] and total He dissolved in the residual liquid without appreciably changing the He-3/He-4 ratio. This is because the isotopic composition of the He of the initial bulk fluid is unchanged and there is too little time for much radiogenic He-4 to build back into the liquid during this rapid ascent from the near-surface reservoir. However, if boiling with phase separation and loss of steam occurs deep in the system, the He-3/He-4 ratio in the residual liquid. now depleted in H2S and total He, will be susceptible to dilution with radiogenic He-4 that is acquired during the longer residence time underground. Some or all of the Au that comes out of solution when an initial gold bisulfide complex breaks down as a result of loss of H2S may be swept up to the surface as solid (probably colloidal) particles, depending on the rate of flow of the mixture of water and steam, and the geometry of the channel. Where colloidal silica also forms as a result of this boiling, free Au apparently becomes attached to the colloidal silica and deposits where the silica deposits. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. RP FOURNIER, RO (reprint author), US GEOL SURVEY,MS-910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 57 TC 10 Z9 10 U1 0 U2 4 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 1994 VL 58 IS 24 BP 5401 EP 5419 DI 10.1016/0016-7037(94)90238-0 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300003 ER PT J AU WAITE, TD DAVIS, JA PAYNE, TE WAYCHUNAS, GA XU, N AF WAITE, TD DAVIS, JA PAYNE, TE WAYCHUNAS, GA XU, N TI URANIUM(VI) ADSORPTION TO FERRIHYDRITE - APPLICATION OF A SURFACE COMPLEXATION MODEL SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; AMORPHOUS IRON OXYHYDROXIDE; OXIDE-WATER INTERFACE; FINE-STRUCTURE; IONIZATION; URANYL; ION; HYDROLYSIS; CARBONATE; CHEMISTRY AB A study of U(VI) adsorption by ferrihydrite was conducted over a wide range of U(VI) concentrations, pH, and at two partial pressures of carbon dioxide. A two-site (strong- and weak-affinity sites, =Fe3OH and =FewOH, respectively) surface complexation model was able to describe the experimental data well over a wide range of conditions, with only one species formed with each site type: an inner-sphere, mononuclear, bidentate complex of the type (=FeO2)UO2. The existence of such a surface species was supported by results of uranium EXAFS spectroscopy performed on two samples with U(VI) adsorption density in the upper range observed in this study (10 and 18% occupancy of total surface sites). Adsorption data in the alkaline pH range suggested the existence of a second surface species, modeled as a ternary surface complex with UO2CO30 binding to a bidentate surface site. Previous surface complexation models for U(VI) adsorption have proposed surface species that are identical to the predominant aqueous species, e.g., multinuclear hydrolysis complexes or several U(VI)-carbonate complexes. The results demonstrate that the speciation of adsorbed U(VI) may be constrained by the coordination environment at the surface, giving rise to surface speciation for U(VI) that is significantly less complex than aqueous speciation. C1 AUSTRALIAN NUCL SCI & TECHNOL ORG,ENVIRONM SCI PROGRAM,MENAI,NSW 2234,AUSTRALIA. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. STANFORD UNIV,CTR MAT RES,STANFORD,CA 94305. RI Payne, Timothy/F-2545-2010; Waite, T. David/A-1400-2008 OI Payne, Timothy/0000-0002-3502-7567; Waite, T. David/0000-0002-5411-3233 NR 49 TC 495 Z9 502 U1 14 U2 151 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 1994 VL 58 IS 24 BP 5465 EP 5478 DI 10.1016/0016-7037(94)90243-7 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PY693 UT WOS:A1994PY69300008 ER PT J AU MANN, GM AF MANN, GM TI LATE CENOZOIC STRUCTURE AND CORRELATION TO SEISMICITY ALONG THE OLYMPIC-WALLOWA LINEAMENT, NORTHWESTERN UNITED-STATES - REPLY SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Note RP MANN, GM (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 8 TC 2 Z9 2 U1 0 U2 2 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 DEC PY 1994 VL 106 IS 12 BP 1639 EP 1641 PG 3 WC Geosciences, Multidisciplinary SC Geology GA PU924 UT WOS:A1994PU92400012 ER PT J AU BEHRMANN, JH LEWIS, SD CANDE, SC MUSGRAVE, R BANGS, N BODEN, P BROWN, K COLLOMBAT, H DIDENKO, AN DIDYK, BM FROELICH, PN GOLOVCHENKO, X FORSYTHE, R KURNOSOV, V LINDSLEYGRIFFIN, N MARSAGLIA, K OSOZAWA, S PRIOR, D SAWYER, D SCHOLL, D SPIEGLER, D STRAND, K TAKAHASHI, K TORRES, M VEGAFAUNDEZ, M VERGARA, H WASADA, A AF BEHRMANN, JH LEWIS, SD CANDE, SC MUSGRAVE, R BANGS, N BODEN, P BROWN, K COLLOMBAT, H DIDENKO, AN DIDYK, BM FROELICH, PN GOLOVCHENKO, X FORSYTHE, R KURNOSOV, V LINDSLEYGRIFFIN, N MARSAGLIA, K OSOZAWA, S PRIOR, D SAWYER, D SCHOLL, D SPIEGLER, D STRAND, K TAKAHASHI, K TORRES, M VEGAFAUNDEZ, M VERGARA, H WASADA, A TI TECTONICS AND GEOLOGY OF SPREADING RIDGE SUBDUCTION AT THE CHILE TRIPLE JUNCTION - A SYNTHESIS OF RESULTS FROM LEG-141 OF THE OCEAN DRILLING PROGRAM SO GEOLOGISCHE RUNDSCHAU LA English DT Article DE SPREADING RIDGE SUBDUCTION; CHILE TRIPLE JUNCTION; ODP LEG [4]; TECTONICS; PACIFIC OCEAN; SOUTH AMERICA; CHILE; FORE-ARC; OPHIOLITE; SEDIMENT; DEFORMATION ID ACCRETIONARY PRISM; CONVERGENT MARGINS; SOUTHERN CHILE; SEDIMENT SUBDUCTION; SOUTHWEST JAPAN; TRENCH; EVOLUTION; EROSION; PACIFIC; ZONE AB An active oceanic spreading ridge is being subducted beneath the South American continent at the Chile Triple Junction. This process has played a major part in the evolution of most of the continental margins that border the Pacific Ocean basin. A combination of high resolution swath bathymetric maps, seismic reflection profiles and drillhole and core data from five sites drilled during Ocean Drilling Program (ODP) Leg 141 provide important data that define the tectonic, structural and stratigraphic effects of this modern example of spreading ridge subduction. A change from subduction accretion to subduction erosion occurs along-strike of the South American forearc. This change is prominently expressed by normal faulting, forearc subsidence, oversteepening of topographic slopes and intensive sedimentary mass wasting, overprinted on older signatures of sediment accretion, overthrusting and uplift processes in the forearc. Data from drill sites north of the triple junction (Sites 859 - 861) show that after an important phase of forearc building in the early to late Pliocene, subduction accretion had ceased in the late Pliocene. Since that time sediment on the downgoing oceanic Nazca plate has been subducted. Site 863 was drilled into the forearc in the immediate vicinity of the triple junction above the subducted spreading ridge axis. Here, thick and intensely folded and faulted trench slope sediments of Pleistocene age are currently involved in the frontal deformation of the forearc. Early faults with thrust and reverse kinematics are overprinted by later normal faults. The Chile Triple Junction is also the site of apparent ophiolite emplacement into the South American forearc. Drilling at Site 862 on the Taitao Ridge revealed an offshore volcanic sequence of Plio-Pleistocene age associated with the Taitao Fracture Zone, adjacent to exposures of the Pliocene-aged Taitao ophiolite onshore. Despite the large-scale loss of material from the forearc at the triple junction, ophiolite emplacement produces a large topographic promontory in the forearc immediately after ridge subduction, and represents the first stage of forearc rebuilding. C1 US GEOL SURVEY, BRANCH PACIFIC MARINE GEOL, MENLO PK, CA 94025 USA. TEXAS A&M UNIV, OCEAN DRILLING PROGRAM, COLLEGE STN, TX 77845 USA. UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, LA JOLLA, CA 92093 USA. INST GEOPHYS, AUSTIN, TX 78759 USA. UNIV STOCKHOLM, DEPT GEOL & GEOCHEM, S-10691 STOCKHOLM, SWEDEN. MISS ORSTOM, QUITO, ECUADOR. RUSSIAN ACAD SCI, INST PHYS EARTH, MOSCOW 123810, RUSSIA. REFINERIA PETR CONCON SA, EMPRESA NACL PETROLOE, CONCEPCION, CHILE. COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA. UNIV N CAROLINA, DEPT GEOG & EARTH SCI, CHARLOTTE, NC 28223 USA. RUSSIAN ACAD SCI, INST GEOL, MOSCOW 109017, RUSSIA. UNIV NEBRASKA, DEPT GEOL, LINCOLN, NE 68588 USA. UNIV TEXAS, DEPT GEOL SCI, EL PASO, TX 79968 USA. TOHOKU UNIV, FAC SCI, INST GEOL & PALAEONTOL, AOBA KU, SENDAI, MIYAGI 980, JAPAN. UNIV LIVERPOOL, DEPT EARTH SCI, LIVERPOOL L69 3BX, MERSEYSIDE, ENGLAND. RICE UNIV, DEPT GEOL & GEOPHYS, HOUSTON, TX 77251 USA. GEOMAR, W-2300 KIEL 1, GERMANY. UNIV OULU, DEPT GEOL, SF-90570 OULU, FINLAND. WOODS HOLE OCEANOG INST, DEPT GEOL & GEOPHYS, WOODS HOLE, MA 02543 USA. UNIV CATOLICA NORTE, DEPT CIENCIAS GEOL, ANTOFAGASTA, CHILE. SERV HIDROGRAF & OCEANOGRAF ARMADA CHILE, DEPT OCEANOG, VALPARAISO, CHILE. JAPEX, RES CTR, CHIBA 260, JAPAN. RP BEHRMANN, JH (reprint author), UNIV GIESSEN, INST GEOWISSENSCH & LITHOSPHARENFORSCH, SENCKENBERGSTR 3, D-35390 GIESSEN, GERMANY. RI Bangs, Nathan/A-1584-2009; Sawyer, Dale/B-7667-2013 OI Bangs, Nathan/0000-0002-4377-3463; Sawyer, Dale/0000-0002-6915-1486 NR 94 TC 51 Z9 51 U1 0 U2 11 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0016-7835 J9 GEOL RUNDSCH JI Geol. Rundsch. PD DEC PY 1994 VL 83 IS 4 BP 832 EP 852 PG 21 WC Geosciences, Multidisciplinary SC Geology GA PY885 UT WOS:A1994PY88500015 ER PT J AU PHILLIPS, FM CAMPBELL, AR SMITH, GI BISCHOFF, JL AF PHILLIPS, FM CAMPBELL, AR SMITH, GI BISCHOFF, JL TI INTERSTADIAL CLIMATIC CYCLES - A LINK BETWEEN WESTERN NORTH-AMERICA AND GREENLAND SO GEOLOGY LA English DT Article ID SEARLES LAKE; ICE CORE; C-14 AB During the interval 33.6 to 26.1 ka, Searles Lake in southeastern California went through six major cycles of expansion and contraction. A comparison of U/Th ages for these events with the chronologies for quasi-cyclic interstadial episodes in the ice core from Summit, Greenland, suggests that the episodes of low water at Searles Lake are synchronous with the interstadial episodes at Summit. The two phenomena may be linked by variations in the strength of the global hydrological cycle, driven by oscillations in the Atlantic Ocean thermohaline circulation. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP PHILLIPS, FM (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT GEOSCI,SOCORRO,NM 87801, USA. NR 21 TC 40 Z9 43 U1 1 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 DEC PY 1994 VL 22 IS 12 BP 1115 EP 1118 DI 10.1130/0091-7613(1994)022<1115:ICCALB>2.3.CO;2 PG 4 WC Geology SC Geology GA PU923 UT WOS:A1994PU92300015 ER PT J AU WATTERSON, JR AF WATTERSON, JR TI ARTIFACTS RESEMBLING BUDDING BACTERIA PRODUCED IN PLACER-GOLD AMALGAMS BY NITRIC-ACID LEACHING SO GEOLOGY LA English DT Article ID INVOLVEMENT; ORIGIN AB Microscopic filiform morphologies in gold which are indistinguishable from forms originally interpreted as bacterial in origin were produced in the laboratory by treating amalgams made from natural and artificial gold with hot nitric acid. Textures ranging from cobblestone to deeply crenulated to nodular filiform were produced in the laboratory from all tested natural and artificial gold amalgams; analogous textures widespread in Alaskan placer gold may have a similar inorganic origin. These results indicate that morphology alone cannot be considered adequate evidence of microbial involvement in gold formation. RP WATTERSON, JR (reprint author), US GEOL SURVEY,DENVER,CO 80225, USA. NR 4 TC 14 Z9 14 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 DEC PY 1994 VL 22 IS 12 BP 1144 EP 1146 DI 10.1130/0091-7613(1994)022<1144:ARBBPI>2.3.CO;2 PG 3 WC Geology SC Geology GA PU923 UT WOS:A1994PU92300022 ER PT J AU LYONS, PC AF LYONS, PC TI RHYOLITIC GLASS IN ORDOVICIAN K-BENTONITES - A NEW STRATIGRAPHIC TOOL - COMMENT SO GEOLOGY LA English DT Note RP LYONS, PC (reprint author), US GEOL SURVEY,MS 956,NATL CTR,RESTON,VA 22092, USA. NR 4 TC 1 Z9 1 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 1994 VL 22 IS 12 BP 1151 EP 1151 DI 10.1130/0091-7613(1994)022<1151:RGIOKB>2.3.CO;2 PG 1 WC Geology SC Geology GA PU923 UT WOS:A1994PU92300027 ER PT J AU NELSON, PH JOHNSTON, D AF NELSON, PH JOHNSTON, D TI GEOPHYSICAL AND GEOCHEMICAL LOGS FROM A COPPER-OXIDE DEPOSIT, SANTA-CRUZ PROJECT, CASA-GRANDE, ARIZONA SO GEOPHYSICS LA English DT Article AB In support of an in-situ leaching experiment, five holes drilled into a copper oxide deposit have been logged with geophysical and geochemical tools developed for use in the petroleum industry. When combined with geological description, chemical analyses, and mineralogical data from core and cuttings, the logs provide information regarding the alteration, fracturing, copper distribution, porosity, and permeable zones. Correlations among sonic velocity, rock strength from mechanical tests on core, and alteration indicators from neutron and potassium logs demonstrate a close link between the state of alteration and the mechanical state of the rock. Neutron activation, natural gamma-ray, and density logs, in combination, correlate so well with copper assays that log-based prediction of copper content is possible; in addition, an estimate of whole-rock mineralogy is presented in log format. Based on comparisons of flow logs and acoustic logs obtained in the same holes, reductions in acoustic velocity appear to be the best indicators of permeability increases. C1 SCHLUMBERGER WELL SERV,DALLAS,TX 75244. RP NELSON, PH (reprint author), US GEOL SURVEY,DENVER FED CTR,GEOPHYS BRANCH,POB 25046,MS 964,DENVER,CO 80225, USA. NR 16 TC 6 Z9 6 U1 0 U2 2 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD DEC PY 1994 VL 59 IS 12 BP 1827 EP 1838 DI 10.1190/1.1443570 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PV800 UT WOS:A1994PV80000004 ER PT J AU POORE, RZ CHANDLER, MA AF POORE, RZ CHANDLER, MA TI SIMULATING PAST CLIMATES - THE DATA-MODEL CONNECTION SO GLOBAL AND PLANETARY CHANGE LA English DT Editorial Material ID NORTH-ATLANTIC OCEAN; PLIOCENE C1 NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. RP POORE, RZ (reprint author), US GEOL SURVEY,NATL CTR,MS 955,RESTON,VA 22092, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1994 VL 9 IS 3-4 BP 165 EP 167 DI 10.1016/0921-8181(94)90014-0 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PZ127 UT WOS:A1994PZ12700001 ER PT J AU DOWSETT, H THOMPSON, R BARRON, J CRONIN, T FLEMING, F ISHMAN, S POORE, R WILLARD, D HOLTZ, T AF DOWSETT, H THOMPSON, R BARRON, J CRONIN, T FLEMING, F ISHMAN, S POORE, R WILLARD, D HOLTZ, T TI JOINT INVESTIGATIONS OF THE MIDDLE PLIOCENE CLIMATE .1. PRISM PALEOENVIRONMENTAL RECONSTRUCTIONS SO GLOBAL AND PLANETARY CHANGE LA English DT Review ID NORTH-ATLANTIC OCEAN; EARLY PLEISTOCENE CLIMATE; CENOZOIC GLACIAL HISTORY; ANTARCTIC ICE-SHEET; UNITED-STATES; POLLEN RECORD; COASTAL-PLAIN; LATE NEOGENE; EAST-AFRICA; SEA-LEVEL AB The Pliocene epoch represents an important transition from a climate regime with high-frequency, low-amplitude oscillations when the Northern Hemisphere lacked substantial ice sheets, to the typical high-frequency, high-amplitude Middle to Late Pleistocene regime characterized by glacial-interglacial cycles that involve waxing and waning of major Northern Hemisphere ice sheets. Analysis of middle Pliocene (similar to 3 Ma) marine and terrestrial records throughout the Northern Hemisphere forms the basis of an integrated synoptic Pliocene paleoclimate reconstruction of the last significantly warmer than present interval in Earth history. This reconstruction, developed primarily from paleontological data, includes middle Pliocene sea level, vegetation, land-ice distribution, sea-ice distribution, and sea-surface temperature (SST), all of which contribute to our conceptual understanding of this climate system. These data indicate middle Pliocene sea level was at least 25 m higher than present, presumably due in large part to a reduction in the size of the East Antarctic Ice Sheet. Sea surface temperatures were essentially equivalent to modern temperatures in tropical regions but were significantly warmer at higher latitudes. Due to increased heat flux to high latitudes, both the Arctic and Antarctic appear to have been seasonally ice free during the middle Pliocene with greatly reduced sea ice extent relative to today during winter. Vegetation changes, while more complex, are generally consistent with marine SST changes and show increased warmth and moisture at higher latitudes during the middle Pliocene. C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. RP DOWSETT, H (reprint author), US GEOL SURVEY,970 NATL CTR,RESTON,VA 22092, USA. OI Dowsett, Harry/0000-0003-1983-7524 NR 151 TC 129 Z9 133 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1994 VL 9 IS 3-4 BP 169 EP 195 DI 10.1016/0921-8181(94)90015-9 PG 27 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PZ127 UT WOS:A1994PZ12700002 ER PT J AU CHANDLER, M RIND, D THOMPSON, R AF CHANDLER, M RIND, D THOMPSON, R TI JOINT INVESTIGATIONS OF THE MIDDLE PLIOCENE CLIMATE .2. GISS GCM NORTHERN-HEMISPHERE RESULTS SO GLOBAL AND PLANETARY CHANGE LA English DT Article ID CLOUD OPTICAL-THICKNESS; DOUBLED CO2 CLIMATE; HEAT TRANSPORTS; ATMOSPHERIC MODEL; HIGHER HIMALAYAS; 2-PHASE UPLIFT; ICE-AGE; 17 MA; PALEOCLIMATE; OCEAN AB Marine microfaunal data and terrestrial pollen records indicate that the middle Pliocene (ca. 3 Ma) climate is the most recent period in geologic history with global temperatures nearly as warm as those predicted for the coming century. We used the GISS GCM to examine the Pliocene climate by specifying sea surface temperatures and vegetation distributions derived from U.S.G.S. data sets. The simulation resulted in 1.4 degrees C warming, annually averaged over the Northern Hemisphere. Warming was greatest at high latitudes; consequently, the equator to pole temperature gradient decreased by 11.5 degrees C. Surface air temperature increases were greatest in winter, as decreased snow and sea ice triggered a positive albedo feedback effect. At low latitudes, temperatures were mostly unchanged except for an anomalous 3 degrees C cooling over eastern Africa. This anomaly is supported by palynological data and, in the simulation, was a response to the weakening of the Hadley circulation, which caused subtropical clouds and evapotranspiration rates to increase. Evaporation and precipitation rates decreased over the oceans and the appearance of negative P-E anomalies might have implications for the Pliocene thermohaline circulation. The hydrological cycle intensified over the continents, where annual evaporation, rainfall, and soil moisture all increased. However, simulated summer drought conditions are not corroborated by terrestrial records, pointing to deficiencies in either the model, the boundary conditions, or the terrestrial data interpretations. The Pliocene SST pattern implicates increased ocean heat flux as a component force behind the middle Pliocene warmth, since levels of CO2, large enough to cause the extreme high latitude temperatures, would generate more tropical warming than is indicated by floral and faunal records. Surface energy fluxes, calculated by the GCM, indicate that an increased meridional ocean heat nux of 32% could reproduce the data-derived SST distribution, despite weakened atmospheric transports. The decreased wind stress values suggest that any increase of ocean heat transports would probably have resulted from a strengthening of the thermohaline circulation. C1 US GEOL SURVEY,DENVER,CO 80225. NASA,GODDARD SPACE FLIGHT CTR,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. RP CHANDLER, M (reprint author), COLUMBIA UNIV,2880 BROADWAY,NEW YORK,NY 10025, USA. NR 49 TC 90 Z9 95 U1 12 U2 40 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD DEC PY 1994 VL 9 IS 3-4 BP 197 EP 219 DI 10.1016/0921-8181(94)90016-7 PG 23 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PZ127 UT WOS:A1994PZ12700003 ER PT J AU BREDEHOEFT, JD AF BREDEHOEFT, JD TI HAZARDOUS-WASTE REMEDIATION - A 21ST-CENTURY PROBLEM SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article AB The United States, both the private and the public sector, is currently spending approximately $10 billion annually on environmental cleanup. In 1991, the Waste Management Research and Education Institute at the University of Tennessee, Knoxville, complete an exhaustive study that estimated if we continue to pursue current policies the total cost of the cleanup will be approximately $750 billion - in 1990 dollars. This suggests that given current technology and the current rate of expenditure, cleanup will take 75 years-well into the latter half of the next century. The legacy of environmental problems associated with our weapons complex is enormous. The Tennessee group estimated that one-third of the total cost of cleanup-approximately $240 billion-will be borne by the Department of Energy (DOE). Currently approximately one-half of the annual expenditures for cleanup comes from DOE-$5 billion, one-third of the DOE budget. In contrast, the amount of funds for basic research on environmental cleanup problems is small. The federal government spends less than $100 million annually for basic research-less than 1 percent of the total annual expenditure of $10 billion. This level of funding for basic research seems shortsighted given the current status of cleanup technologies and the expected long duration of the problem. RP BREDEHOEFT, JD (reprint author), USGS,MENLO PK,CA 94025, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD WIN PY 1994 VL 14 IS 1 BP 95 EP 100 DI 10.1111/j.1745-6592.1994.tb00093.x PG 6 WC Water Resources SC Water Resources GA MT150 UT WOS:A1994MT15000008 ER PT J AU ROSEBOOM, EH AF ROSEBOOM, EH TI NUCLEAR GRIDLOCK SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP ROSEBOOM, EH (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD WIN PY 1994 VL 10 IS 2 BP 13 EP 14 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA MQ255 UT WOS:A1994MQ25500014 ER PT J AU LINDSEY, GD ARENDT, WJ KALINA, J AF LINDSEY, GD ARENDT, WJ KALINA, J TI SURVIVAL AND CAUSES OF MORTALITY IN JUVENILE PUERTO-RICAN PARROTS SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article AB Fifteen juvenile Puerto Rican Parrots (Amazona vittala) from wild nests in 1985, 1986 and 1987 were radio monitored an average of 110 +/- 15.9 (SE) d (range 4-209 d) post-fledging. Minimum survival was 67% (n = 3) in 1985, 100% (n = 4) in 1986 and 43% (n = 7) in 1987. Most mortality (three of five deaths) occurred during the first 35 d following fledging. A major cause of mortality was predation by raptors. This research shows that additional studies are needed to define mortality causes to juvenile and adult free-flying Puerto Rican Parrots and to develop management guidelines to increase survival. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. US FOREST SERV,INST TROP FORESTRY,SO FOREST EXPT STN,RIO PIEDRAS,PR 00928. NR 12 TC 26 Z9 26 U1 0 U2 1 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 WIN PY 1994 VL 65 IS 1 BP 76 EP 82 PG 7 WC Ornithology SC Zoology GA ND148 UT WOS:A1994ND14800011 ER PT J AU TEAL, MJ ETTEMA, R WALKER, JF AF TEAL, MJ ETTEMA, R WALKER, JF TI ESTIMATION OF MEAN FLOW VELOCITY IN ICE-COVERED CHANNELS SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article AB Point-measurement methods for estimating the mean velocity of vertical distributions of streamwise velocity in ice-covered channels are evaluated in this paper. The evaluation uses profiles generated numerically, based on a two-power law description of vertical distribution of streamwise velocity. The two-power law simplifies into the well-known power-law expression for open-water velocity profiles. Its validity was verified using measured velocity profiles obtained from rivers and a laboratory flume. The profiles are representative of flows subject to various combinations of bed and ice-cover conditions. Values of estimation bias (the percent error in estimating average velocity from a few point measurements instead of integrating over the entire vertical velocity profile) were determined for several point-measurement methods, including those currently used by the United States Geological Survey (USGS) and the Water Survey of Canada, and proposed new methods. The systematic variation of bias values with ice-cover and bed-resistance conditions was also determined. The method with the least overall bias is the so-called usual two-point method, in which velocity measurements taken at 0.2 and 0.8 of now depth are averaged to obtain an estimate of mean velocity. This method produces a remarkably small bias; its maximum value is close to 2%. Estimation accuracy is enhanced if a coefficient of 0.98 is applied to the two-point method. C1 UNIV IOWA,IOWA INST HYDRAUL RES,IOWA CITY,IA 52242. US GEOL SURVEY,MADISON,WI 53719. NR 17 TC 13 Z9 19 U1 0 U2 5 PU ASCE-AMER SOC CIVIL ENGINEERS 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 DEC PY 1994 VL 120 IS 12 BP 1385 EP 1400 DI 10.1061/(ASCE)0733-9429(1994)120:12(1385) PG 16 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA PT784 UT WOS:A1994PT78400003 ER PT J AU TINDALL, JA LULL, KJ GAGGIANI, NG AF TINDALL, JA LULL, KJ GAGGIANI, NG TI EFFECTS OF LAND DISPOSAL OF MUNICIPAL SEWAGE-SLUDGE ON FATE OF NITRATES IN SOIL, STREAMBED SEDIMENT, AND WATER-QUALITY SO JOURNAL OF HYDROLOGY LA English DT Article AB This study was undertaken to determine the effects of sewage-sludge disposal at the Lowry sewage-sludge-disposal area, near Denver, Colorado, on ground- and surface-water quality, to determine the fate of nitrates from sludge leachate, and to determine the source areas of leachate and the potential for additional leaching from the disposal area. Sewage-sludge disposal began in 1969. Two methods were used to apply the sludge: burial and plowing. Also, the sludge was applied both in liquid and cake forms. Data in this report represent the chemical composition of soil and streambed sediment from seven soil- and four streambed-sampling sites in 1986, chemical and bacterial composition of ground water from 28 wells from 1981 to 1987, and surface-water runoff from seven water-sampling sites from 1984 to 1987. Ground water samples were obtained from alluvial and bedrock aquifers. Samples of soil, streambed sediment, ground water and surface water were obtained for onsite measurement and chemical analysis. Measurements included determination of nitrogen compounds and major cations and anions, fecal-coliform and -streptococcus bacteria, specific conductance, and pH. Thirteen wells in the alluvial aquifer in Region 3 of the study area contain water that was probably affected by sewage-sludge leachate. The plots of concentration of nitrate with time show seasonal trends and trends caused by precipitation. In addition to yearly fluctuation, there were noticeable increases in ground-water concentrations of nitrate that coincided with increased precipitation. After 3 years of annual ground-water-quality monitoring and 4 years of a quarterly sampling program, it has been determined that leachate from the sewage-sludge-disposal area caused increased nitrite plus nitrate (as nitrogen) concentration in the alluvial ground water at the site. Soil analyses from the disposal area indicate that organic nitrogen was the dominant form of nitrogen in the soil. As a result of investigations at the research site, it has been determined that a potentially large source of contamination exists in the soils of the study area owing to increased concentrations of nitrogen, sodium, calcium, magnesium, sulfate, bicarbonate, and chloride because of sewage disposal. Continued monitoring of surface and ground water for nitrogen and the other ions previously mentioned is required to assess long-term effects of municipal sludge disposal on water quality. RP TINDALL, JA (reprint author), US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,MS 413,BOX 25046,DENVER,CO 80225, USA. NR 25 TC 5 Z9 6 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD DEC 1 PY 1994 VL 163 IS 1-2 BP 147 EP 185 DI 10.1016/0022-1694(94)90027-2 PG 39 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA QA087 UT WOS:A1994QA08700009 ER PT J AU BACON, CR GUNN, SH LANPHERE, MA WOODEN, JL AF BACON, CR GUNN, SH LANPHERE, MA WOODEN, JL TI MULTIPLE ISOTOPIC COMPONENTS IN QUATERNARY VOLCANIC-ROCKS OF THE CASCADE ARC NEAR CRATER LAKE, OREGON SO JOURNAL OF PETROLOGY LA English DT Article ID PARTIALLY MELTED GRANODIORITE; CALCALKALINE MAGMA CHAMBER; OXYGEN-ISOTOPE; NORTHERN CALIFORNIA; KLAMATH MOUNTAINS; STABLE ISOTOPE; TRACE-ELEMENT; COMPOSITIONAL ZONATION; RHYOLITIC MAGMA; SILICIC MAGMAS AB Quaternary lavas and pyroclastic rocks of Mount Mazama, Crater Lake caldera, and the surrounding area have variable Sr, Nd, and Pb isotopic compositions. High-alumina olivine tholeiites (HAOT) have Sr-87/Sr-86 ratios of 0.70346-0.70364; basaltic andesite, 0.70349-0.70372; shoshonitic basaltic andesite, 0.70374-0.70388; and andesite, 0.70324-0.70383. Dacites of Mount Mazama have Sr-87/Sr-86 ratios of 0.70348-0.70373. Most rhyodacites converge on 0.7037. However, rhyodacite of the caldera-forming, climactic eruption has Sr-87/Sr-86=0.70354 because of an admired low-Sr-87/Sr-86 component. Andesitic to mafic-cumulate scoriae of the climactic eruption, and enclaves in preclimactic rhyodacites, cluster in two groups but show nearly the entire Sr-87/Sr-86 range of the data set, confirming previously suggested introduction of diverse parental magmas into the growing climactic chamber. Pb and Nd isotope ratios display less variation ((206)pb/Pb-204 = 18.838-18.967, Pb-207/Pb-204 = 15.556-15.616, Pb-208/Pb-204 = 38.405-38.619; epsilon(Nd) = +3.9 to +6.1) and generally covary with Sr-87/Sr-86 ratios. Radiogenic isotope data from Crater Lake plot with published data for other Cascade volcanoes on isotope ratio correlation diagrams. The isotopic data for the Crater Lake area require sources of primitive magmas to consist of depleted mantle and a subduction component, introduced in variable quantity to the depleted mantle wedge. Variable degrees of melting of this heterogeneous mantle, possibly at different depths, produced the diversity of isotopic compositions and large-ion lithophile element (LILE) abundances in primitive magmas. Trace element ratios do not indicate presence of an ocean island basalt (GIB) source component that has been reported in lavas of some other Cascade volcanoes. Crustal contamination may have affected isotope ratios and LILE concentrations in evolved HAOT, where initial LILE concentrations were low. Contamination is more difficult to detect in the calcalkaline lavas because of their higher LILE concentrations and the small isotopic contrast with likely contaminants, such as mid- to lower-crustal rocks thought to be equivalents of igneous rocks of the Klamath Mountains and associated lower crust. Crustal assimilation appears to be required for calcalkaline rocks only by delta(18)O values, which vary from lows of +5.6 to +6.0 parts per thousand in HAOT and primitive basaltic andesites to a high of + 7.0 parts per thousand in dacite, a range that is too high to be explained by plagioclase-dominated closed-system fractional crystallization. Elevated delta(18)O values of differentiated lavas may be attributed to interaction with relatively O-18-rich, Sr-87-poor crustal rocks. Variably fused granitoid blocks ejected in the climactic eruption, and rarely in late Pleistocene eruptive units, have delta(18)O(pl) of - 3.4 to + 6.5 parts per thousand and delta(18)O(qz) of - 2.2 to + 8.0 parts per thousand but have Sr, Nd, and Pb isotope ratios similar to volcanic rocks (e.g. Sr-87/Sr-86 approximate to 0.7037). Rb and Sr data for glass separates from granodiorites suggest that the source pluton is Miocene. Glass from granodiorite has Sr-87/Sr-86 ratios as high as 0.70617. Oxygen isotope fractionation between quartz, plagioclase, and glass indicates reequilibration of O isotopes at magmatic temperatures, after O-18/O-16 had been lowered by exchange with meteoric hydrothermal fluids. Unmelted granodiorite xenoliths from pre-climactic eruptive units have delta(18)O values that are consistent with onset of hydrothermal exchange early during growth of the climactic magma chamber. Assimilation of such upper-crustal granodiorite apparently lowered delta(18)O values of rhyodacites without significantly affecting their magmatic compositions in other ways. RP BACON, CR (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 84 TC 30 Z9 30 U1 0 U2 8 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD DEC PY 1994 VL 35 IS 6 BP 1521 EP 1556 PG 36 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QD041 UT WOS:A1994QD04100003 ER PT J AU LOFERSKI, PJ ARCULUS, RJ CZAMANSKE, GK AF LOFERSKI, PJ ARCULUS, RJ CZAMANSKE, GK TI RARE-EARTH ELEMENT EVIDENCE FOR THE PETROGENESIS OF THE BANDED SERIES OF THE STILLWATER COMPLEX, MONTANA, AND ITS ANORTHOSITES SO JOURNAL OF PETROLOGY LA English DT Article ID PARTITION-COEFFICIENTS; BEARTOOTH MOUNTAINS; MANTLE EVOLUTION; BUSHVELD COMPLEX; MAGMA EVOLUTION; PLAGIOCLASE; ORIGIN; CRUST; REEF; ZONE AB A rare earth element (REE) study was made by isotope-dilution mass spectrometry of plagioclase separates from a variety of cumulates stratigraphically spanning the Banded series of the Stillwater Complex, Montana. Evaluation of parent liquid REE patterns, calculated on the basis of published plagioclase-liquid partition coefficients, shows that the range of REE ratios is too large to be attributable to fractionation of a single magma type. At least two different parental melts were present throughout the Banded series. This finding supports hypotheses of previous workers that the Stillwater Complex formed from two different parent magma types, designated the anorthositic- or A-type liquid and the ultramafic- or U-type liquid. On the basis of our data, one melt has a REE pattern with a distinctive shallow slope and is represented by samples from the thick, massive Anorthosite zones I and II (AN I and AN II) of the Middle Banded series. Although samples from AN I and AN II are separated by as much as 1400 m stratigraphically, they have remarkably similar calculated parent liquid characteristics, with (Ce/Sm)n = 1.7-1.9, (Nd/Sm)(n) = 1.3-1.4 and (Ce/Yb)(n) = 2.9-4.6 (where n denotes chondrite-normalized). These calculated liquids are probably close to representing A-type magma. In addition, plagioclase-bronzite cumulates from Norite zones I and II (N I and N II), although thought to be U-type cumulates, contain plagioclase that has A-type REE characteristics, implying that A-type magmas were injected into the magma chamber during formation of those zones. In contrast, calculated parent liquids of cumulus augite-bearing rocks have REE patterns that display distinctly steeper slopes than the A-type REE pattern. The extreme is the calculated parent liquid of a plagioclase-bronzite-augite cumulate with (Ce/Sm)(n) = 2.9, (Nd/Sm)(n) = 1.7, and (Ce/Yb)(n) = 10.1. Analysis of published REE and Nd isotopic data for Stillwater cumulates reveals similarities between AN I, AN II, and other thin plagioclase cumulate layers in the Lower and Upper Banded series, which supports the notion that they were all derived from similar (A-type) parent melts. In contrast, plagioclase separates from cumulus augite-bearing rocks display light REE and Nd isotopic characteristics that are similar to U-type cumulates from the Ultramafic series as described by previous studies. Thus far, the only cumulates from the Banded series that display U-type REE and Nd isotopic characteristics are those that contain cumulus augite. Therefore, cumulus augite appears to be an important indicator of magmatic parentage. The REE and Nd isotopic ratios show erratic variation with stratigraphic position, indicating that the magmas from which the Banded series crystallized were injected at various levels into the magma chamber. Different cumulate types crystallized from discrete liquids, as indicated by the correlation between REE signature and cumulate type. Samples from Olivine-bearing zones III and IV (stratigraphically between AN I and AN II) display a range in REE ratios; e.g., (Ce/Sm)(n) = 1.8-2.8 and (Ce/Yb)(n) = 3.9-6.1, results that rule out the crystallization of the Middle Banded series from a single magma type. Furthermore, the possibility that AN I and AN II are directly related to the underlying Ultramafic series, either as flotation cumulates or as crystallization products of expelled liquids, is not substantiated by the REE data because the calculated parent magma of AN I and AN II was different from that of the Ultramafic series as defined by previous studies. The REE data of this study further constrain interpretations of published Pb isotopic data (Wooden et al., 1991)and indicate that the magmas from which the Stillwater Complex formed were derived from two sources that had only small differences in Pb isotopic composition. The REE and isotopic data, as well as crystallization sequences of the two main parental magmas, indicate that the magmas were probably derived from two closely related upper-mantle sources, one harzburgitic and the other lherzolitic in composition, resulting in the U-type and A-type magmas, from which orthopyroxene crystallized before and after clinopyroxene, respectively. Both sources had been enriched in large-ion lithophile elements, probably owing to mantle metasomatism. C1 AUSTRALIAN NATL UNIV,DEPT GEOL,CANBERRA,ACT 0200,AUSTRALIA. US GEOL SURVEY,MENLO PK,CA 94025. RP LOFERSKI, PJ (reprint author), US GEOL SURVEY,954 NATL CTR,RESTON,VA 22092, USA. NR 40 TC 9 Z9 9 U1 1 U2 7 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD DEC PY 1994 VL 35 IS 6 BP 1623 EP 1649 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QD041 UT WOS:A1994QD04100006 ER PT J AU STOUT, MZ NICHOLLS, J KUNTZ, MA AF STOUT, MZ NICHOLLS, J KUNTZ, MA TI PETROLOGICAL AND MINERALOGICAL VARIATIONS IN 2500-2000 YR BP LAVA FLOWS, CRATERS OF THE MOON LAVA-FIELD, IDAHO SO JOURNAL OF PETROLOGY LA English DT Article ID SNAKE-RIVER-PLAIN; VOLCANIC-ROCKS; CHEMICAL CLASSIFICATION; NOMENCLATURE; BASALTS; USA AB Basaltic lava flows were erupted 2500-2000 yr B.P. along the Great Rift volcanic rift zone at the Craters of the Moon lava field in the Snake River Plain volcanic province, Idaho. These flows form a diverse suite of rock types near the northern edge of the Snake River Plain but typical Snake River Plain olivine basalts were erupted nearly contemporaneously at the center of the plain. The Craters of the Moon lava flows range from basalt to trachyte, whereas rocks typical of the Snake River Plain are olivine basalt and rhyolite with no intermediate types. The Craters of the Moon lava flows have chemical and mineralogical features that do not fit conveniently into any of several currently recommended rock classifications. Suggested names for the Craters of the Moon rocks, based on color index, SiO2, P2O5 and TiO2 contents, modal feldspar plus glass contents, Fa contents of olivine, and feldspar compositions, are basalt, trachybasalt, tristanite, and trachyte. Both the Craters of the Moon and Snake River Plain rocks are dominated by plagioclase and olivine and contain minor or lesser amounts of pyroxene. However, the Craters of the Moon rocks lack the Mg-Al and Cr-rich spinels and the Mg-rich olivines found in Snake River Plain basalts. Instead, the Craters of the Moon lava flows contain Fe-rich olivine, rare Fe-rich pyroxene, and minor alkali feldspar. Accessory minerals in the Craters of the Moon rocks are zircon and apatite. Chemical and mineralogical data, including Thompson space representations and mass balance calculations, suggest a genetic link between the Snake River Plain basalts and the Craters of the Moon lava flows. Thermodynamic modeling suggests that augite could appear on the liquidus of the Craters of the Moon lava flows at high pressures and including a more magnesian (earlier?) pyroxene in the fractionating assemblage improves the least-squares mass balance result. Processes of crystal fractionation and accumulation, overprinted by contamination by pumiceous rhyolite, can account for much of the diversity within the rock types from the Craters of the Moon lava field. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP STOUT, MZ (reprint author), UNIV CALGARY,CALGARY,AB T2N 1N4,CANADA. NR 46 TC 17 Z9 17 U1 0 U2 8 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD DEC PY 1994 VL 35 IS 6 BP 1681 EP 1715 PG 35 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QD041 UT WOS:A1994QD04100008 ER PT J AU LAMBERT, DD WALKER, RJ MORGAN, JW SHIREY, SB CARLSON, RW ZIENTEK, ML LIPIN, BR KOSKI, MS COOPER, RL AF LAMBERT, DD WALKER, RJ MORGAN, JW SHIREY, SB CARLSON, RW ZIENTEK, ML LIPIN, BR KOSKI, MS COOPER, RL TI RE-OS AND SM-ND ISOTOPE GEOCHEMISTRY OF THE STILLWATER COMPLEX, MONTANA - IMPLICATIONS FOR THE PETROGENESIS OF THE J-M REEF SO JOURNAL OF PETROLOGY LA English DT Review ID PLATINUM-GROUP ELEMENTS; IONIZATION MASS-SPECTROMETRY; MINNEAPOLIS ADIT AREA; BEARTOOTH MOUNTAINS; LAYERED INTRUSIONS; MANTLE EVOLUTION; TRACE-ELEMENTS; RHENIUM-OSMIUM; MERENSKY-REEF; SUBCONTINENTAL MANTLE AB Re-Os and Sm-Nd isotopic data have been obtained for mafic and ultramafic cumulates from the 2700-Ma Stillwater Complex and associated fine-grained sills and dykes, so as to better constrain the geochemical characteristics of Stillwater parental magmas and to trace the source(s) of the precious metals that have been concentrated in the J-M Reef, the major platinum-group element mineral deposit in the complex. Initial Os isotopic compositions (Os-187/Os-188) for chromitites from the Ultramafic series range from a radiogenic isotopic composition of 0.1321 (gamma(Os) = +21) for the platinum group element (PGE)-enriched B chromitite seam from the West Fork area to a near-chondritic isotopic composition of 0.1069-0.1135 (gamma(Os) = -2 to +4.1) for the PGE-poor G and H chromitite seams, respectively, near the middle of the Ultramafic series. Osmium isotopic data for the POE-rich B chromitite seam are generally isochronous with whole-rock and mineral data for the J-M Reef (gamma(Os) = +12 to +34). Re-Os isotopic data therefore document a contrast between POE-poor cumulates from the Ultramafic series and POE-enriched cumulates from both the Ultramafic series and the J-M Reef, suggesting that Os and probably the other PGE were derived from at least two isotopically distinct sources. Moreover, these Re-Os isotopic characteristics correlate with petrogenetic subdivisions of the Stillwater Complex based on field mapping, petrology, REE geochemistry, and Sm-Nd isotope geochemistry. The data are best explained by mixing of two magma types, referred to as U-type and A-type magmas, with differing major element, trace element, and precious metal abundances and isotopic compositions. Although crustally contaminated komatiites can mimic the Os and Nd isotopic characteristics of the U-type magma, the combination of low initial Os isotopic values (gamma(Os) similar to 0) with low initial Nd isotopic values (epsilon(Nd) less than or equal to -1), high Pb-207/Pb-204 for a given Pb-206/Pb-204 (Wooden et al., 1991), and high (Ce/Yb)(n) ratios in U-type cumulates and fine-grained sills and dykes is more consistent with the involvement of a Re-poor, but trace-element-enriched portion of the subcontinental lithospheric mantle in the petrogenesis of Stillwater U-type magmas. However, the radiogenic initial Os isotopic compositions of the J-M Reef and other portions of the intrusion with elevated PGE concentrations suggest that A-type parental magmas incorporated Os from radiogenic early Archaean crust. The relatively large range in (Ce/Yb)(n) gamma(Os) and epsilon(Nd) values suggests that mixing of geochemically distinct magmas may have been an important process throughout the history of the Stillwater magma chamber. Magma mixing may then explain not only the PGE-enriched J-M Reef but also the anomalous enrichment of the PGE in the B chromitite seam from the West Fork area and the variable gamma(Os) values observed in other chromitite seams of the Ultramafic series. The intimate association of these magma types, derived from or modified in the Archaean continental lithosphere, may then be crucial to the formation of magmatic PGE mineral deposits. C1 UNIV MARYLAND,DEPT GEOL,COLLEGE PK,MD 20742. US GEOL SURVEY,RESTON,VA 22092. CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,WASHINGTON,DC 20015. US GEOL SURVEY,SPOKANE,WA 99201. STILLWATER MIN CO,NYE,MT 59061. LAMAR UNIV,DEPT GEOL,BEAUMONT,TX 77710. RP LAMBERT, DD (reprint author), MONASH UNIV,VICTORIAN INST EARTH & PLANETARY SCI,DEPT EARTH SCI,CLAYTON,VIC 3168,AUSTRALIA. RI Walker, Richard/K-6869-2016 OI Walker, Richard/0000-0003-0348-2407 NR 117 TC 83 Z9 89 U1 1 U2 5 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD DEC PY 1994 VL 35 IS 6 BP 1717 EP 1753 PG 37 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QD041 UT WOS:A1994QD04100009 ER PT J AU FISHER, SW DABROWSKA, H WALLER, DL BABCOCKJACKSON, L ZHANG, X AF FISHER, SW DABROWSKA, H WALLER, DL BABCOCKJACKSON, L ZHANG, X TI OF ZEBRA MUSSEL (DREISSENA-POLYMORPHA) LIFE STAGES TO CANDIDATE MOLLUSCICIDES SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE ZEBRA MUSSEL; VELIGERS; PLANTIGRADE; TOXICITY; MOLLUSCICIDE ID GROWTH; MORTALITY; LARVAE; COPPER AB We developed methods for measuring the toxicity of candidate molluscicides to several life stages (preveliger, D-stage veliger, post-D stage veliger, plantigrade, and adult) of the zebra mussel Dreissena polymorpha: Veligers were obtained by inducing ripe adults to spawn in the laboratory and by field collection. Plantigrades were collected on slides suspended in Lake Erie. The toxicity of candidate molluscicides on all stages was evaluated in 24 hour static tests in hard standard reference water. The sensitivity of zebra mussel life stages to different chemicals varied. Veliger stages showed similar sensitivity to Bayer 73 and TFM, whereas plantigrades and adults were less sensitive. Sensitivity to Calgon H-130, Clamtrol CT-1, and Sal I decreased with each successive developmental stage; adults were most and preveligers were least sensitive to rotenone. In general, chemical concentrations that kill adults will also be effective against other life stages. However, because chemical minimization strategies require the use of the smallest amount of chemical possible, molluscicides should be tested on the life stage targeted for control. C1 US FISH & WILDLIFE SERV,NATL FISHERIES RES CTR,LA CROSSE,WI 54602. RP FISHER, SW (reprint author), OHIO STATE UNIV,DEPT ENTOMOL,1735 NEIL AVE,COLUMBUS,OH 43210, USA. NR 22 TC 19 Z9 21 U1 1 U2 2 PU NATL SHELLFISHERIES ASSOC PI SOUTHHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHHAMPTON, NY 11968 SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 1994 VL 13 IS 2 BP 373 EP 377 PG 5 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA QC151 UT WOS:A1994QC15100005 ER PT J AU TALBOT, SS TALBOT, SL AF TALBOT, SS TALBOT, SL TI NUMERICAL CLASSIFICATION OF THE COASTAL VEGETATION OF ATTU ISLAND, ALEUTIAN ISLANDS, ALASKA SO JOURNAL OF VEGETATION SCIENCE LA English DT Article; Proceedings Paper CT International Workshop on Classification of Arctic Vegetation CY MAR 05-09, 1992 CL UNIV COLORADO, INST ARCTIC & ALPINE RES, BOULDER, CO HO UNIV COLORADO, INST ARCTIC & ALPINE RES DE BEACH; CLUSTER ANALYSIS; CORRESPONDENCE ANALYSIS; DUNE; ELYMUS MOLLIS; MULVA-4; ORDINATION; PHYTOGEOGRAPHIC COMPARISON AB This phytosociological study of the beaches, dunes, and associated lower mountain slopes of Attu Island is the first effort to identify the major coastal vegetation types of the Aleutian Islands using numerical methods. It is the first attempt to use the releve method in southern coastal Alaska and provides a basis for future comparison with other areas. 76 releves represent the range of structural and compositional variation in the matrix of vegetation and landform zonation at 16 locations. Data are analyzed by multivariate methods using the MULVA-4 computer package and ordered with Wildi's numerical procedure to produce results similar to traditional phytosociological tabular classification. Nine major community types are distinguished in four physiognomic groups: 1. Dwarf-shrub mire: Vaccinium uliginosum-Empetrum nigrum; 2. Meadow: Athyrium filix-femina-Streptopus amplexifolius, Arremisia tilesii-Veratrum album, Elymus mollis-Montia (Claytonia) sibirica, Ligusticum scoticurn-Elymus mollis; 3. Beach meadow: Elymus mollis-Senecio pseudo-arnica, Lathyrus maritimus-Elymus mollis; and 4. Beach: Mertensia maritima and Arenaria (Honckenya) peploides. These community types are described and interpreted in response to a complex, topographic gradient. Phytogeographic comparison of Attu Island with neighboring areas suggests close relationship to the beach and beach-meadow types of eastern Kamchatka and to the mesic meadows of the Alaskan Semidi Islands; there is a slightly lower relationship to the mesic meadows of nearby Buldir Island. RP TALBOT, SS (reprint author), US FISH & WILDLIFE SERV,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. RI Talbot, Sandra/C-9433-2011 NR 0 TC 14 Z9 14 U1 0 U2 4 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 DEC PY 1994 VL 5 IS 6 BP 867 EP 876 DI 10.2307/3236199 PG 10 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA QG236 UT WOS:A1994QG23600010 ER PT J AU HOLTZ, TR AF HOLTZ, TR TI THE ARCTOMETATARSALIAN PES, AN UNUSUAL STRUCTURE OF THE METATARSUS OF CRETACEOUS THEROPODA (DINOSAURIA, SAURISCHIA) SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Review ID STENONYCHOSAURUS-INEQUALIS SAURISCHIA; LIMB BONES; INTERNAL FORCES; CRANIAL ANATOMY; EXTINCT EQUIDS; LOCOMOTION; BIRDS; ORIGIN; HORSE; MAMMALS AB The Cretaceous theropod families Omithomimidae, Tyrannosauridae, Troodontidae, Elmisauridae, and Avimimidae share an unusual condition of the metatarsus. The central (third) metatarsal is greatly reduced proximally, completely excluded from anterior view and nearly to completely excluded in dorsal aspect. This bone forms a wedge shape distally, triangular in transverse cross section, which is buttressed against the more columnar metatarsals II and IV. This morphology forms a tightly bound structure, here termed the arctometatarsalian condition. Morphometric analysis indicates that the arctometatarsalian structure is significantly more elongate and gracile than underived metatarsi, and this structure is associated with relatively elongate distal hind limbs per unit femoral length. When compared with limb proportions of modern and extinct mammals and flightless birds, these limb proportions are seen to be consistent with a hypothesis of enhanced cursoriality in the derived theropods. In some genera, intrametatarsal mobility in this structure may have served as an energy storage system analogous to the snap-ligaments of modern equids. The wedge-and-buttress morphology would have resulted in a more direct transmission of locomotory forces to the epipodium than in less derived theropods. Biomechanical analysis indicates that this type of relatively gracile pes was not significantly weaker than pedes of underived theropods with regards to bending stresses, due to elongation into the parasagittal plane. To the contrary, these metatarsi were well designed to withstand the forces and stresses associated with enhanced cursorial ability. RP HOLTZ, TR (reprint author), US GEOL SURVEY, MS 970 NATL CTR, RESTON, VA 22092 USA. NR 125 TC 75 Z9 79 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0272-4634 EI 1937-2809 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD DEC PY 1994 VL 14 IS 4 BP 480 EP 519 PG 40 WC Paleontology SC Paleontology GA QG844 UT WOS:A1994QG84400004 ER PT J AU BENSON, LV WHITE, JWC AF BENSON, LV WHITE, JWC TI STABLE ISOTOPES OF OXYGEN AND HYDROGEN IN THE TRUCKEE RIVER PYRAMID LAKE SURFACE-WATER SYSTEM .3. SOURCE OF WATER-VAPOR OVERLYING PYRAMID LAKE SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article AB During 1988 and 1989, a series of water-vapor extractions were conducted in the Pyramid Lake basin to determine the source of moisture that overlies the lake. Calculations of the isotopic and water-vapor balances were made from isotopic and meteorological data from the Pyramid Lake and Reno, Nevada, areas. The results indicate that in the warm season, most of the moisture that overlies the lake is derived from evaporation as opposed to advected moisture. Isotopic fluxes at the lake surface can be approximated by climatic data from the lake site, which simplifies the calculation of this input in numerical simulations of the isotopic evolution of the lake. C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. RP BENSON, LV (reprint author), US GEOL SURVEY,BOULDER LAB,3215 MARINE ST,BOULDER,CO 80303, USA. RI White, James/A-7845-2009 OI White, James/0000-0001-6041-4684 NR 17 TC 25 Z9 28 U1 0 U2 2 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 DEC PY 1994 VL 39 IS 8 BP 1945 EP 1958 PG 14 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA QG413 UT WOS:A1994QG41300015 ER PT J AU MCKNIGHT, DM ANDREWS, ED SPAULDING, SA AIKEN, GR AF MCKNIGHT, DM ANDREWS, ED SPAULDING, SA AIKEN, GR TI AQUATIC FULVIC-ACIDS IN ALGAL-RICH ANTARCTIC PONDS SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Note ID HUMIC SUBSTANCES AB We isolated fulvic acids from two antarctic coastal ponds by means of preparative scale column chromatography with XAD-8 resin. Both ponds are on Ross Island. Pony Lake at Cape Royds has abundant phytoplankton populations, and Feather Pond at Cape Bird has a luxuriant benthic algal mat. Neither site has higher plants in the watershed. The dissolved organic carbon (DOC) concentration in Pony Lake was very high, but the percentage of DOC accounted for by fulvic acid was low, as has been observed for other lakes with algal-derived DOC sources. Fulvic acid from Pony Lake was more enriched in nitrogen than fulvic acid from Feather Pond, with a C:N atomic ratio of 13 in Pony Lake and a C:N ratio of 24 in Feather Pond. The [C-13]NMR spectra for the coastal pond samples showed that the content of sp(2)-hybridized carbon atoms (aromatic or olefinic) was only 16.5% of the total spectral area for Pony Lake and only 20.1% for Feather Pond. RP MCKNIGHT, DM (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 16 TC 166 Z9 168 U1 2 U2 31 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 DEC PY 1994 VL 39 IS 8 BP 1972 EP 1979 PG 8 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA QG413 UT WOS:A1994QG41300018 ER PT J AU ISHMAN, SE DOMACK, EW AF ISHMAN, SE DOMACK, EW TI OCEANOGRAPHIC CONTROLS ON BENTHIC FORAMINIFERS FROM THE BELLINGSHAUSEN MARGIN OF THE ANTARCTIC PENINSULA SO MARINE MICROPALEONTOLOGY LA English DT Article ID HOLOCENE GLACIER FLUCTUATIONS; BRANSFIELD STRAIT REGION; POLAR FRONT REGION; BULIMINA-MARGINATA; WEDDELL SEA; SEDIMENTATION; ECOLOGY; ASSEMBLAGES; ACULEATA; ATLANTIC AB Surface sediment samples collected from the Bellingshausen Sea continental margin of the Antarctic Peninsula were analyzed for benthic foraminifers. A total fauna including live and dead specimen counts was used to statistically identify discrete benthic foraminifer assemblages. Two major assemblages were defined, the Bulimina aculeata and Fursenkoina spp. Assemblages. The distribution of the Bulimina aculeata and Fursenkoina spp. Assemblages are closely associated with the distribution of the two dominant bottom water masses on the continental margin, the Circumpolar Warm Deep Water and Weddell Sea Transitional Water, respectively. Their distributions cannot be related to organic carbon content or sediment texture of the surface sediments. The faunal composition of the Bellingshausen Sea margin assemblages and their water mass associations are similar to faunal-water mass relationships observed in the Weddell Sea and South Atlantic Ocean where Bulimina aculeata is associated with Circumpolar Deep Water and Nonionella iridea, N. bradii and Trifarina earlandi are associated with Eastern Shelf and Modified Weddell Sea Water. C1 HAMILTON COLL,DEPT GEOL,CLINTON,NY 13323. RP ISHMAN, SE (reprint author), US GEOL SURVEY,NATL CTR,MS 970,RESTON,VA 22092, USA. NR 54 TC 43 Z9 44 U1 0 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 1994 VL 24 IS 2 BP 119 EP 155 DI 10.1016/0377-8398(94)90019-1 PG 37 WC Paleontology SC Paleontology GA QG609 UT WOS:A1994QG60900004 ER PT J AU FRIEDMAN, JD CONRAD, JE MCKEE, EH MUTSCHLER, FE ZARTMAN, RE AF FRIEDMAN, JD CONRAD, JE MCKEE, EH MUTSCHLER, FE ZARTMAN, RE TI POSSIBLE MESOZOIC AGE OF ELLENVILLE ZN-PB-CU(AG) DEPOSIT, SHAWANGUNK MOUNTAINS, NEW-YORK SO MINERALIUM DEPOSITA LA English DT Article ID NEW-ENGLAND APPALACHIANS; FOLD-THRUST BELT; K-AR; IGNEOUS PROVINCES; UNITED-STATES; NEW-HAMPSHIRE; BASIN; PENNSYLVANIA; EVOLUTION; CONNECTICUT AB Ore textures, epithermal open-space filling of Permian structures of the Alleghanian orogeny, and largely postorogenic mineralization of the Ellenville, New York, composite Zn-Pb-Cu(Ag) vein system, provide permissive evidence for post-Permian mineralization. Isochron ages determined by Ar-40/Ar-39 laser-fusion techniques for K-bearing liquid inclusions in main-stage quartz from the Ellenville deposit additionally suggest a Mesozoic time of mineralization, associated with extensional formation of the Newark basin. The best Ar-40/Ar-39 total-fusion age range is 165 +/- 30 to 193 +/- 35 Ma. The Mesozoic Ar-40/Ar-39 age agrees with that of many other dated northern Appalachian Zn-Pb-Cu(AE) deposits with near-matching lead isotope ratios, and adds new evidence of Jurassic tectonism and mineralization as an overprint to Late Paleozoic tectonism at least as far north as Ellenville (lat. 41 degrees 43'N). C1 US GEOL SURVEY,MENLO PK,CA 94025. EASTERN WASHINGTON UNIV,DEPT GEOL,CHENEY,WA 99004. RP FRIEDMAN, JD (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 78 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0026-4598 J9 MINER DEPOSITA JI Miner. Depos. PD DEC PY 1994 VL 29 IS 6 BP 474 EP 487 PG 14 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PX722 UT WOS:A1994PX72200003 ER PT J AU TAGGART, JE FOORD, EE SHIGLEY, JE AF TAGGART, JE FOORD, EE SHIGLEY, JE TI CHEMICAL-COMPOSITION AND STRUCTURAL FORMULA OF MANGANOAN SUGILITE FROM THE WESSELS MINE, REPUBLIC-OF-SOUTH-AFRICA SO MINERALOGICAL MAGAZINE LA English DT Note DE MANGANOAN SUGILITE; WESSELS MINE; REPUBLIC OF SOUTH AFRICA ID CRYSTAL-CHEMISTRY C1 GEMOL INST AMER,GIA RES,SANTA MONICA,CA 90404. RP TAGGART, JE (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,DENVER,CO 80225, USA. NR 17 TC 3 Z9 3 U1 0 U2 4 PU MINERALOGICAL SOCIETY PI LONDON PA 41 QUEENS GATE, LONDON, ENGLAND SW7 5HR SN 0026-461X J9 MINERAL MAG JI Mineral. Mag. PD DEC PY 1994 VL 58 IS 393 BP 679 EP 681 DI 10.1180/minmag.1994.058.393.19 PG 3 WC Mineralogy SC Mineralogy GA QF132 UT WOS:A1994QF13200019 ER PT J AU NORMARK, WR PIPER, DJW AF NORMARK, WR PIPER, DJW TI TURBIDITE SEDIMENTATION SO OCEANUS LA English DT Article C1 GEOL SURVEY CANADA,BEDFORD INST OCEANOG,OTTAWA K1A 0E8,ONTARIO,CANADA. RP NORMARK, WR (reprint author), US GEOL SURVEY,DENVER,CO 80225, USA. NR 0 TC 0 Z9 1 U1 0 U2 3 PU WOODS HOLE OCEANOGRAPHIC INST PI WOODS HOLE PA OCEANUS MAGAZINE, WOODS HOLE, MA 02543 SN 0029-8182 J9 OCEANUS JI Oceanus PD WIN PY 1994 VL 36 IS 4 BP 107 EP 110 PG 4 WC Oceanography SC Oceanography GA ND528 UT WOS:A1994ND52800032 ER PT J AU SHEETS, BA YOST, WP AF SHEETS, BA YOST, WP TI GROUNDWATER CONTRIBUTION FROM THE SILURIAN DEVONIAN CARBONATE AQUIFER TO THE MAD RIVER VALLEY, SOUTHWESTERN OHIO SO OHIO JOURNAL OF SCIENCE LA English DT Article AB The U.S. Geological Survey Regional Aquifer-System Analysis is examining the Silurian and Devonian carbonate aquifer and overlying glacial deposits of western Ohio and eastern Indiana in terms of the hydrogeologic framework, ground-water-flow system and water chemistry, and response to withdrawals and development. This paper describes the hydrogeology of an area in southwestern Ohio that contains the Mad River Valley, an outwash valley that is incised through the relatively permeable Silurian bedrock into the relatively impermeable Ordovician bedrock at the southern boundary of Silurian rocks. Ground-water-flow patterns based on a synoptic water-level survey of 80 bedrock wells in the Silurian and Devonian carbonate aquifer indicate that flow is toward the valley. A ground-water basin was delineated from the potentiometric-surface map and used in conjunction with a low-flow gain-loss study to derive a generalized ground-water/surface-water budget for the area. Results of this budget indicate that ground-water recharge rates through the ground moraine to the carbonate aquifer range from 4 to 6 in/yr (10-15 cm/yr) and that approximately 60 to 80% of the base flow in the Mad River may ultimately consist of ground water derived from the Silurian and Devonian carbonate aquifer. Previous studies of surface- and ground-water chemistry in the area also support the conclusion that the Mad River Valley functions as a discharge area for the surrounding carbonate aquifer. Results of this study can be useful in characterizing ground-water flow and recharge rates for the Silurian and Devonian carbonate and valley aquifers along the southern boundary of this extensive regional aquifer system. RP SHEETS, BA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,COLUMBUS,OH 43212, USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU OHIO ACAD SCIENCE PI COLUMBUS PA 1500 W 3RD AVE SUITE 223, COLUMBUS, OH 43212-2817 SN 0030-0950 J9 OHIO J SCI JI Ohio J. Sci. PD DEC PY 1994 VL 94 IS 5 BP 138 EP 146 PG 9 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA QC628 UT WOS:A1994QC62800004 ER PT J AU KVENVOLDEN, KA RAPP, JB HOSTETTLER, FD ROSENBAUER, RJ AF KVENVOLDEN, KA RAPP, JB HOSTETTLER, FD ROSENBAUER, RJ TI LABORATORY SIMULATION OF HYDROTHERMAL PETROLEUM FORMATION FROM SEDIMENT IN ESCANABA TROUGH, OFFSHORE FROM NORTHERN CALIFORNIA SO ORGANIC GEOCHEMISTRY LA English DT Article DE HYDROUS PYROLYSIS; HYDROTHERMAL PETROLEUM; ESCANABA TROUGH; GORDA RIDGE; MOLECULAR MARKERS; ALKANES; ISOPRENOIDS; TRITERPANES; STERANES; CALIFORNIA ID HYDROUS PYROLYSIS; ORGANIC-MATTER; PACIFIC-OCEAN; GORDA RIDGE; MATURATION; HYDROCARBONS; PARAMETERS; KEROGENS; STERANES; SULFIDE AB Petroleum associated with sulfide rich sediment is present in Escanaba Trough at the southern end of the Gorda Ridge spreading axis offshore from northern California within the Exclusive Economic Zone (EEZ) of the U.S. This location and occurrence are important for evaluation of the mineral and energy resource potential of the seafloor under U.S. jurisdiction. In Escanaba Trough, petroleum is believed to be formed by hydrothermal processes acting on mainly terrigenous organic material in Quaternary, river-derived sediment. To attempt to simulate these processes in the laboratory, portions of a Pleistocene gray-green mud, obtained from similar to 1.5 m below the seafloor at a water depth of similar to 3250 m in Escanaba Trough, were heated in the presence of water in four hydrous-pyrolysis experiments conducted at temperatures ranging from 250 to 350 degrees C and at a pressure of 350 bar for 1.0-4.5 days. Distributions of n-alkanes, isoprenoid hydrocarbons, triterpanes, and steranes in the heated samples were compared with those in a sample of hydrothermal petroleum from the same area. Mud samples heated for less than 4.5 days at less than 350 degrees C show changes in some, but not all, molecular marker ratios of organic compounds that are consistent with those expected during hydrothermal petroleum formation. Our results suggest that the organic matter in this type of sediment serves as one possible source for some of the compounds found in the hydrothermal petroleum. RP KVENVOLDEN, KA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 38 TC 2 Z9 2 U1 1 U2 6 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 DEC PY 1994 VL 22 IS 6 BP 935 EP 945 DI 10.1016/0146-6380(94)90030-2 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QT590 UT WOS:A1994QT59000005 ER PT J AU LIGHT, DL AF LIGHT, DL TI MOONSAT - AN ORBITAL IMAGING-SYSTEM FOR MAPPING THE MOON SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID REFLECTANCE AB On 20 July 1989, two decades after the first Apollo landing on the Moon, President George Bush proposed a long-range, continuing commitment that called for revisiting the Moon to establish way-points for the long-range plan to land on Mars. Accepting this challenge, NASA then established the Space Exploration initiative which plans to include a polar orbiting lunar imager to map the Moon. Moonsat is proposed as such a lunar imaging system. Spatial and spectral resolution requirements as proposed enable Moonsat to support mapping of the lunar topography and to determine the composition of soils and rocks for mineralogy and natural resource assessment. Moonsat's design calls for sensing high resolution pixels in the panchromatic band from in-orbit stereo. The position and attitude of Moonsat will be taken from Earth-based tracking and, if feasible, the Global Positioning System when Moonsat is on the visible side, and attitude will be taken from star sensors time-synchronized with the ground-looking linear array sensors. Moonsat's orbital altitude (100 km), period (118 min), spatial resolution (4 m), and swath width (35 km) will provide full contiguous coverage of the Moon's surface. These data can be used for a variety of applications to support the Nation's Space Exploration Initiative. RP LIGHT, DL (reprint author), US GEOL SURVEY,511 NATL CTR,RESTON,VA 22092, USA. NR 27 TC 1 Z9 1 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 1994 VL 60 IS 12 BP 1421 EP 1429 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA PY045 UT WOS:A1994PY04500002 ER PT J AU ATTANASI, ED AF ATTANASI, ED TI US NORTH SLOPE GAS AND ASIAN LNG MARKETS SO RESOURCES POLICY LA English DT Article ID NATURAL-GAS AB Prospects for export of liquefied natural gas (LNC) from Alaska's North Slope are assessed. Projected market conditions to 2010 show that new LNG capacity beyond announced expansions will be needed to meet regional demand and that supplies will probably come from outside the region. The estimated delivered costs of likely suppliers show that Alaska North Slope gas will not be competitive. The alternative North Slope gas development strategies of transport and sale to the lower 48 states and use on the North Slope for either enhanced oil recovery or conversion to liquids are examined. The alternative options require delaying development until US gas prices increase, exhaustion of certain North Slope oil fields, or advances occur in gas to liquid fuels conversion technology. RP ATTANASI, ED (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 920,RESTON,VA 22092, USA. NR 24 TC 0 Z9 0 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA LINACRE HOUSE JORDAN HILL, OXFORD, OXON, ENGLAND OX2 8DP SN 0301-4207 J9 RESOUR POLICY JI Resour. Policy PD DEC PY 1994 VL 20 IS 4 BP 247 EP 255 DI 10.1016/0301-4207(94)90004-3 PG 9 WC Environmental Studies SC Environmental Sciences & Ecology GA RA085 UT WOS:A1994RA08500004 ER PT J AU GUTERMUTH, FB LENTSCH, LD BESTGEN, KR AF GUTERMUTH, FB LENTSCH, LD BESTGEN, KR TI COLLECTION OF AGE-0 RAZORBACK SUCKERS (XYRAUCHEN-TEXANUS) IN THE LOWER GREEN RIVER, UTAH SO SOUTHWESTERN NATURALIST LA English DT Note RP GUTERMUTH, FB (reprint author), US FISH & WILDLIFE SERV,LINCOLN PLAZA SUITE 404,145 E 1300 S,SALT LAKE CITY,UT 84115, USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU SOUTHWESTERN ASSN NATURALISTS PI SAN MARCOS PA SOUTHWEST TEXAS STATE UNIV, DEPT BIOLOGY, 601 UNIVERSITY DR, SAN MARCOS, TX 78666 SN 0038-4909 J9 SOUTHWEST NAT JI Southw. Natural. PD DEC PY 1994 VL 39 IS 4 BP 389 EP 391 PG 3 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA QF697 UT WOS:A1994QF69700016 ER PT J AU ANDERSON, RE BARNHARD, TP SNEE, LW AF ANDERSON, RE BARNHARD, TP SNEE, LW TI ROLES OF PLUTONISM, MIDCRUSTAL FLOW, TECTONIC RAFTING, AND HORIZONTAL COLLAPSE IN SHAPING THE MIOCENE STRAIN FIELD OF THE LAKE MEAD AREA, NEVADA AND ARIZONA SO TECTONICS LA English DT Article ID WESTERN UNITED-STATES; VALLEY SHEAR ZONE; STRIKE-SLIP; SOUTHEASTERN NEVADA; CRUSTAL EXTENSION; GREAT-BASIN; SOUTHERN NEVADA; TERTIARY ROCKS; BLOCK ROTATION; CLARK-COUNTY AB The Lake Mead area contains a well-exposed record of highly contrasting Neogene structural development that includes major magmatism and extension in its southern part and large-magnitude lateral translations (to 65 km) of amagmatic structural blocks in its northern part. These highly contrasting parts are joined at the Hamblin Bay fault, a major crustal boundary that forms the south margin of the Lake Mead fault system and the north margin of the lower Colorado River extensional corridor. Intrusive rocks adjacent to this crustal boundary on the south record major crustal rifting normal to an 350 degrees axis. They also display steep-axis disharmonic folds that formed by postmagmatic extension-related horizontal collapse of highly weakened crust. The rocks directly north of the crustal boundary not only display large lateral translations, but they also are cut by fault systems suggestive of diverse paleostress conditions and formed into diversely oriented coeval folds collectively producing a complex Neogene deformation field that defies interpretation in terms of a uniform system of remote stresses. Because structures forming this complex deformation field range from outcrop scale to 65 km of lateral displacement and can not be uniformly partitioned according to relative age, we prefer tectonic models based on a protracted uniform dynamic process or superposed dynamic processes to models based on time-varying states of stress. We suggest that the large lateral displacements and extreme structural complexity record synextensional rafting of structural blocks atop a flowing undermass and concomitant contraction of the zone of flowage. Structural blocks north of the main zone of flowage (the Great Basin sector of the Basin and Range) moved southward and occluded to the block south of the zone (the Colorado River extensional corridor) as a large westward widening wedge of upper crust was carried to the west-southwest toward California on the flowing undermass. Where occlusion is almost complete in the northern Black Mountains, north-south shortening is estimated at 55 km. The narrow zone of strong rifting, plutonism, crustal softening, and horizontal collapse that developed at the north margin of the Colorado River extensional corridor is interpreted to result from contact with the zone of crustal flowage. RP ANDERSON, RE (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MAIL STOP 966,DENVER,CO 80225, USA. NR 77 TC 37 Z9 37 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 DEC PY 1994 VL 13 IS 6 BP 1381 EP 1410 DI 10.1029/94TC01320 PG 30 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PV534 UT WOS:A1994PV53400004 ER PT J AU CONSTANTZ, J THOMAS, CL ZELLWEGER, G AF CONSTANTZ, J THOMAS, CL ZELLWEGER, G TI INFLUENCE OF DIURNAL-VARIATIONS IN STREAM TEMPERATURE ON STREAMFLOW LOSS AND GROUNDWATER RECHARGE SO WATER RESOURCES RESEARCH LA English DT Article ID WATER TEMPERATURE; INFILTRATION; SYSTEMS AB We demonstrate that for losing reaches with significant diurnal variations in stream temperature, the effect of stream temperature on streambed seepage is a major factor contributing to reduced afternoon streamflows. An explanation is based on the effect of stream temperature on the hydraulic conductivity of the streambed, which can be expected to double in the 0 degrees to 25 degrees C temperature range. Results are presented for field experiments in which stream discharge and temperature were continuously measured for several days over losing reaches at St. Kevin Gulch Colorado, and Tijeras Arroyo, New Mexico. At St. Kevin Gulch in July 1991, the diurnal stream temperature in the 160-m study reach ranged from about 4 degrees to 18 degrees C, discharges ranged from 10 to 18 L/s, and streamflow loss in the study reach ranged from 2.7 to 3.7 L/s. On the basis of measured stream temperature variations, the predicted change in conductivity was about 38%; the measured change in stream loss was about 26%, suggesting that streambed temperature varied less than the stream temperature. At Tijeras Arroyo in May 1992, diurnal stream temperature in the 655-m study reach ranged from about 10 degrees to 25 degrees C and discharge ranged from 25 to 55 L/s. Streamflow loss was converted to infiltration rates by factoring in the changing stream reach surface area and streamflow losses due to evaporation rates as measured in a hemispherical evaporation chamber. Infiltration rates ranged from about 0.7 to 2.0 m/d, depending on time and location. Based on measured stream temperature variations, the predicted change in conductivity was 29%; the measured change in infiltration was also about 27%. This suggests that high infiltration rates cause rapid convection of heat to the streambed. Evapotranspiration losses were estimated for the reach and adjacent flood plain within the arroyo. On the basis of these estimates, only about 5% of flow loss was consumed via stream evaporation and stream-side evapotranspiration, indicating that 95% of the loss within the study reach represented groundwater recharge. C1 US GEOL SURVEY,DIV WATER RESOURCES,ALBUQUERQUE,NM 87110. RP CONSTANTZ, J (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MS 496,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 38 TC 115 Z9 116 U1 2 U2 24 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 1994 VL 30 IS 12 BP 3253 EP 3264 DI 10.1029/94WR01968 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA PU142 UT WOS:A1994PU14200003 ER PT J AU NICHOLS, WD AF NICHOLS, WD TI GROUNDWATER DISCHARGE BY PHREATOPHYTE SHRUBS IN THE GREAT-BASIN AS RELATED TO DEPTH TO GROUNDWATER SO WATER RESOURCES RESEARCH LA English DT Article ID ENERGY-TRANSPORT; SPARSE CROPS; RESISTANCES AB An equation describing the mean daily discharge of groundwater by transpiration from phreatophyte shrubs as a function of plant density, leaf area index, and depth to groundwater was developed using an energy combination model calibrated with energy fluxes calculated from micrometeorological data. The energy combination model partitions the energy budget between the soil and canopy permitting plant transpiration to be separated from evaporation from the soil. The shrubs include greasewood, rabbitbrush, shadscale, and sagebrush. Converting a daily groundwater discharge rate calculated by the equation to an annual rate requires an estimate of the number of days the plants used only groundwater. Rates used during previous studies in the Great Basin range from 0.030 to 0.152 m yr(-1) rates calculated with the equation developed during this study range from 0.024 to 0.308 m yr(-1) for the reported field conditions. Annual rates estimated in this study differ from the estimated annual rates used in previous studies by factors ranging from 0.8 to 5.0. RP NICHOLS, WD (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,333 W NYE LANE,CARSON CITY,NV 89706, USA. NR 33 TC 53 Z9 53 U1 0 U2 13 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 1994 VL 30 IS 12 BP 3265 EP 3274 DI 10.1029/94WR02274 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA PU142 UT WOS:A1994PU14200004 ER PT J AU HAUKOS, DA SMITH, LM AF HAUKOS, DA SMITH, LM TI COMPOSITION OF SEED BANKS ALONG AN ELEVATIONAL GRADIENT IN PLAYA WETLANDS SO WETLANDS LA English DT Article DE PLAYA; SEED BANK; SOUTHERN HIGH-PLAINS; WETLAND AB We analyzed the composition of seed banks dong an elevational gradient (0-1 m) in playa wetlands of the Southern High Plains of Texas. Differing seed-bank composition along such a gradient may be one mechanism in the determination of vegetation structure in wetlands. We used the seedling-emergence technique under moist-soil and submerged treatments to ascertain the composition of seed banks in 8 playas. There were no differences (P > 0.05) in overall or common species seedling densities along the elevational gradient. Fluctuating water levels in a relatively shallow wetland, combined with the short linear distance of the gradient into a flat bottom, results in the uniform distribution of seed in playas. Additionally, wind action during periods when playas are dry may serve to distribute seeds throughout the wetland. Structure of vegetation in playas is determined principally by the varying soil moisture regime, which regulates composition of species germinating when other environmental conditions are suitable. When environmental conditions, including soil-moisture content, are appropriate for germination, each species in the seed bank could potentially be found throughout the wetland. When managing playas for specific plant species through manipulation of soil moisture, we can expect a comparable species response to similar treatments anywhere in the playa. RP HAUKOS, DA (reprint author), TEXAS TECH UNIV,DEPT RANGE & WILDLIFE MANAGEMENT,US FISH & WILDLIFE SERV,LUBBOCK,TX 79409, USA. NR 0 TC 29 Z9 29 U1 1 U2 6 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 DEC PY 1994 VL 14 IS 4 BP 301 EP 307 PG 7 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA PZ385 UT WOS:A1994PZ38500006 ER PT J AU STINSON, ER HAYES, LE BUSH, PB WHITE, DH AF STINSON, ER HAYES, LE BUSH, PB WHITE, DH TI CARBOFURAN AFFECTS WILDLIFE ON VIRGINIA CORN FIELDS SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE CARBOFURAN; CARCASS; CORN FIELDS; FURADAN 15G(R); MORTALITY; VIRGINIA; WILDLIFE ID CARBAMATE PESTICIDES; SONGBIRD CARCASSES; BIRDS; RICE; ORGANOPHOSPHATE; FURADAN; TEXAS C1 UNIV GEORGIA,COLL VET MED,SE COOPERAT WILDLIFE DIS STUDY,ATHENS,GA 30601. UNIV GEORGIA,COLL AGR,ATHENS,GA 30601. UNIV GEORGIA,SCH FOREST RESOURCES,SE RES STN,PATUXENT WILDLIFE RES CTR,US FISH & WILDLIFE SERV,ATHENS,GA 30602. RP STINSON, ER (reprint author), VIRGINIA DEPT GAME & INLAND FISHERIES,POB 10428,BLACKSBURG,VA 24062, USA. NR 28 TC 18 Z9 19 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 WIN PY 1994 VL 22 IS 4 BP 566 EP 575 PG 10 WC Biodiversity Conservation SC Biodiversity & Conservation GA PY631 UT WOS:A1994PY63100003 ER PT J AU MORRIS, SR RICHMOND, ME HOLMES, DW AF MORRIS, SR RICHMOND, ME HOLMES, DW TI PATTERNS OF STOPOVER BY WARBLERS DURING SPRING AND FALL MIGRATION ON APPLEDORE-ISLAND, MAINE SO WILSON BULLETIN LA English DT Article ID FAT DEPOSITION; PASSERINE MIGRANTS; SITE; SAHARA; BIRDS; PARULINAE; LENGTH; OASIS; GULF AB Migrant warblers mist netted on Appledore Island, Maine, during spring and fall migration in 1990 and 1991 allowed analysis of seasonal differences in stopover patterns, including recapture rates, stopover lengths, and changes in mass and fat during stopover. Northern Waterthrushes (Seiurus noveboracensis) and American Redstarts (Setophaga ruticilla) had higher recapture rates in the fall than in the spring on Appledore Island. The Ovenbird (Seiurus aurocapillus) and the Canada Warbler (Wilsonia canadensis) had significantly longer stopovers in the fall than in the spring. During fall migration, young Northern Waterthrushes were more likely to be recaptured than adults, and young American Redstarts had longer stopovers than adults. During spring migration, female Magnolia Warblers (Dendroica magnolia) were more likely to be recaptured than males. Higher numbers of both male and female American Redstarts were recaptured in the fall than in the spring. American Redstarts, Northern Waterthrushes, and Ovenbirds showed no significant increase in fat class in the spring, while exhibiting significant increases in fat class in the fall. These three species also exhibited significant increases in mass during fall migration, while only the Ovenbird significantly increased mass in the spring. These data suggest that migrants show species, age, and sex specific seasonal differences in stopover pattern as well as differences in mass and fat accumulation. Such differences are likely affected by hormone titer, risk of predation, seasonal/temporal changes in weather patterns, and/or differences in food availability. Moreover, stopover sites may be used differently as a result of seasonal differences in relation to ecological barriers as well as distances to either breeding or wintering grounds. C1 US FISH & WILDLIFE SERV,WASHINGTON,DC 20240. RP MORRIS, SR (reprint author), CORNELL UNIV,NEW YORK COOPERAT FISH & WILDLIFE RES UNIT,FERNOW HALL,ITHACA,NY 14853, USA. NR 34 TC 37 Z9 37 U1 1 U2 7 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 DEC PY 1994 VL 106 IS 4 BP 703 EP 718 PG 16 WC Ornithology SC Zoology GA PZ524 UT WOS:A1994PZ52400010 ER PT J AU FRANSON, JC HEREFORD, SG AF FRANSON, JC HEREFORD, SG TI LEAD-POISONING IN A MISSISSIPPI SANDHILL CRANE SO WILSON BULLETIN LA English DT Note C1 US FISH & WILDLIFE SERV,NATL WILDLIFE RES CTR,MADISON,WI 53711. US FISH & WILDLIFE SERV,MISSISSIPPI SANDHILL CRANE NATL WILDLIFE REFUGE,GAUTIER,MS 39553. OI Franson, J/0000-0002-0251-4238 NR 15 TC 2 Z9 2 U1 0 U2 2 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 DEC PY 1994 VL 106 IS 4 BP 766 EP 768 PG 3 WC Ornithology SC Zoology GA PZ524 UT WOS:A1994PZ52400021 ER PT J AU MCGREW, AJ SNEE, LW AF MCGREW, AJ SNEE, LW TI AR-40 AR-39 THERMOCHRONOLOGICAL CONSTRAINTS ON THE TECTONOTHERMAL EVOLUTION OF THE NORTHERN EAST HUMBOLDT RANGE METAMORPHIC CORE COMPLEX, NEVADA SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT Meeting on Late Orogenic Extension in Mountain Belts CY MAR 04-06, 1993 CL UNIV MONTPELLIER II, MONTPELLIER, FRANCE SP CNRS, UNIV MONTPELLIER II, BRGM, COGEMA, MINIST RECH & TECHNOL, DELEGAT REG HO UNIV MONTPELLIER II ID NORMAL-FAULT SYSTEMS; RUBY MOUNTAINS; THERMAL CONSTRAINTS; NORTHEASTERN NEVADA; WOOD HILLS; MYLONITIZATION; DEFORMATION; DEPOSITS; HISTORY; AGE AB The northern East Humboldt Range (NEHR) of northeastern Nevada exposes a suite of complexly deformed migmatitic, upper amphibolite-facies rocks in the footwall of the Ruby Mountains-East Humboldt Range (RM-EHR) detachment fault. New Ar-40/Ar-39 data on hornblende, muscovite, biotite, and potassium feldspar help constrain the kinematic and thermal evolution of this terrain during Tertiary extensional exhumation. Hornblende samples from relatively high structural levels yield discordant age spectra that suggest initial cooling during early Tertiary time (63-49 Ma). When coupled with petrological constraints indicating a strongly decompressional P-T-t path above 550 degrees C, the hornblende data suggest that exhumation of the RM-EHR may have initiated in early Tertiary time, approximately coincident with the initial phases of unroofing in the Wood Hills immediately to the east and with the end of thrusting in the late Mesozoic to early Tertiary Sevier orogenic belt of eastern Nevada and western Utah. This temporal coincidence suggests that gravitational collapse of tectonically thickened crust in the internal zone of the Sevier belt could have driven the initial phases of unroofing. Thermal history during the final stage of exhumation of the NEHR is constrained by discordant hornblende cooling ages of 36-29 Ma from deep structural levels and biotite, muscovite, and potassium feldspar cooling ages of 27-21 Ma from a range of structural levels. Comparison of muscovite, biotite, and potassium feldspar cooling ages with previously published fission-track cooling ages implies very rapid cooling rates at temperatures below the closure temperature for muscovite (270 degrees-350 degrees C), but time gaps of > 7 m.y. between hornblende and mica cooling ages suggest that cooling at higher temperatures was more gradual. In addition, comparison of Ar-40/Ar-39 mica cooling ages with previously published fission-track apatite cooling ages suggests pronounced thermal gradients between the NEHR and adjacent areas during latest Oligocene to earliest Miocene time. Such thermal gradients could be readily explained if the RM-EHR detachment fault dipped > 30 degrees between the 300 degrees C and 100 degrees C isotherms. Finally, Ar-40/Ar-39 biotite cooling ages increase southward through the East Humboldt Range, compatible with northward;extrapolation of a previously recognized pattern of WNW-younging biotite cooling ages from the Ruby Mountains. A simple model involving the propagation of footwall uplift in the direction of tectonic transport beneath an initially listric normal fault can explain the principle features of the Oligocene to Miocene thermochronologic data set for the RM-EHR. C1 UNIV WYOMING,DEPT GEOL & GEOPHYS,LARAMIE,WY 82071. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 58 TC 47 Z9 48 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD NOV 15 PY 1994 VL 238 IS 1-4 BP 425 EP 450 DI 10.1016/0040-1951(94)90067-1 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PU403 UT WOS:A1994PU40300022 ER PT J AU QUICK, JE SINIGOI, S MAYER, A AF QUICK, JE SINIGOI, S MAYER, A TI EMPLACEMENT DYNAMICS OF A LARGE MAFIC INTRUSION IN THE LOWER CRUST, IVREA-VERBANO ZONE, NORTHERN ITALY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LOWER CONTINENTAL-CRUST; SOUTHERN-ALPS; WESTERN ALPS; IGNEOUS COMPLEX; DEEP-CRUSTAL; SEISMIC-REFLECTION; POGALLO LINE; CENERI ZONES; MANTLE; EVOLUTION AB The Ivrea-Verbano Zone of northern Italy provides an opportunity to study directly the effects of intrusion of large volumes of mantle-derived melts into the lower continental crust. Alpine uplift has exposed a complex of mafic to intermediate plutonic rocks, which had intruded the lower continental crust during the Permian. Field mapping reveals a gross arcuate structure within the complex that has survived tilting and uplift. In terms of the orientation during intrusion, banding and foliation are subhorizontal near the base of the complex and steepen gradually up section. Outcrop relations indicate that the cumulates were profoundly affected by extensional deformation while they still contained interstitial melts. The intensity of this hypersolidus deformation increases downward in the complex. The above characteristics are explained in terms of a model in which a huge volume of cumulates (8 km thick and > 20 lan long) crystallized from a small (less than or equal to 1 km thick and less than or equal to 4 km wide), periodically refilled magma chamber which remained at a relatively fixed position through time. Large-scale ductile deformation of the complex and transport of cumulates downward and outward from the magma chamber occurred as a consequence of extensional tectonics. This process is capable of generating large sheets of gabbro in the lower crust. Gabbro complexes formed in this manner would be characterized by (1) widespread evidence of synmagmatic deformation dominated by stretching, (2) downward increasing intensity of deformation, (3) upward steepening layering and foliation that is concave toward the center of spreading, and (4) a scarcity of crosscutting intrusive relationships. C1 UNIV TRIESTE, IST MINERAL & PETROG, I-34100 TRIESTE, ITALY. RP QUICK, JE (reprint author), US GEOL SURVEY, DENVER FED CTR, MAIL STOP 903, BOX 25046, DENVER, CO 80225 USA. NR 74 TC 86 Z9 86 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 NOV 10 PY 1994 VL 99 IS B11 BP 21559 EP 21573 DI 10.1029/94JB00113 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500001 ER PT J AU SINIGOI, S QUICK, JE CLEMENSKNOTT, D MAYER, A DEMARCHI, G MAZZUCCHELLI, M NEGRINI, L RIVALENTI, G AF SINIGOI, S QUICK, JE CLEMENSKNOTT, D MAYER, A DEMARCHI, G MAZZUCCHELLI, M NEGRINI, L RIVALENTI, G TI CHEMICAL EVOLUTION OF A LARGE MAFIC INTRUSION IN THE LOWER CRUST, IVREA-VERBANO ZONE, NORTHERN ITALY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CONTINENTAL-CRUST; MAGMA CHAMBER; PARTITION-COEFFICIENTS; GEOCHEMICAL EVOLUTION; IGNEOUS COMPLEX; GABBROIC ROCKS; SOUTHERN ALPS; MANTLE; METAPELITES; ORIGIN AB The Ivrea-Verbano and adjacent Strona-Ceneri zones have been described collectively as a section through the continental crust. While resident in the lower crust, amphibolite- to granulite-facies paragneiss of the Ivrea-Verbano Zone was intruded by huge volumes of mafic to intermediate plutonic rocks grouped as the Mafic Complex. Growth of the Mafic Complex involved hypersolidus deformation in an extensional environment. Isotopic and trace element variations close to the axis of this structure indicate crystallization from mantle-derived melts that were extensively contaminated by crustal material. Previous investigations determined that the contaminant was fingerprinted by Sr-87/Sr-86 > 0.71, delta(18)O = 10-12.5%, and a positive Eu anomaly. In the present study, contaminant is also shown to have been enriched in Ba with respect to Rb and K. Charnockites associated with paragneiss septa in the lower part of the Mafic Complex have the appropriate chemistry to be samples of the contaminating material. These chemical features can be explained by melting of granulite-facies paragneiss, which had previously been depleted in K and RB by an earlier melting event. The Ba enrichment in the core of the Mafic Complex can be modeled by a replenishment-tapping-fractional-crystallization (RTF) process operating within a small magma chamber is repeatedly replenished by mantle melts and contaminated by Ba-rich charnockite. Very high Ba/K in the lower part of the complex are tentatively attributed to chemical exchange between the cumulate framework and infiltrating anatectic melts from underlying paragneiss septa. In contrast to the Mafic Complex, the chemistry of coeval granites in the adjacent Strona-Ceneri zone reflect a component derived from crustal rocks that had not been significantly depleted by a previous melting event. Significantly, the incompatible trace element abundances in the Mafic Complex and Strona-Ceneri granites are similar to model compositions for the lower and upper crust, respectively. C1 US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. CALTECH, DIV GEOL & PLANETARY SCI, PASADENA, CA 91125 USA. UNIV MODENA, IST MINERAL & PETROG, I-41100 MODENA, ITALY. RP SINIGOI, S (reprint author), UNIV TRIESTE, IST MINERAL & PETROG, PIAZZALE EUROPA 1, I-34100 TRIESTE, ITALY. RI Mazzucchelli, Maurizio/L-8637-2015 OI Mazzucchelli, Maurizio/0000-0002-1475-9961 NR 72 TC 70 Z9 70 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 NOV 10 PY 1994 VL 99 IS B11 BP 21575 EP 21590 DI 10.1029/94JB00114 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500002 ER PT J AU ROSE, TP CRISS, RE MUGHANNAM, AJ CLYNNE, MA AF ROSE, TP CRISS, RE MUGHANNAM, AJ CLYNNE, MA TI OXYGEN-ISOTOPE EVIDENCE FOR HYDROTHERMAL ALTERATION WITHIN A QUATERNARY STRATOVOLCANO, LASSEN VOLCANIC NATIONAL-PARK, CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GEOTHERMAL SYSTEM; NEW-ZEALAND; MAGMATIC EVOLUTION; OHAKI-BROADLANDS; MINING DISTRICT; STABLE ISOTOPE; ORE DEPOSITION; CASCADE RANGE; GEOCHEMISTRY; MINERALOGY AB Brokeoff volcano, a Quaternary stratocone located in the Lassen volcanic center in northern California, has been deeply eroded, exposing a 10-km(2) meteoric hydrothermal alteration zone at the core of the volcano. Portions of the former volcanic edifice are sufficiently well preserved that an unusual opportunity exists wherein the alteration pattern can be correlated with the position of the volcanic cone. The delta(18)O analyses of more than 100 whole rock samples, consisting primarily of andesitic lavas, vary from +9.8 to +0.6 per mil. The highest delta(18)O values occur in bleached, solfatarically altered rocks that have interacted with low-pH, fumarolic hot springs associated with the present-day hydrothermal system. Low delta(18)O values are found in propylitically altered rocks that underwent isotopic exchange with meteoric hydrothermal fluids at elevated temperatures, mostly during the stratovolcanic stage (650-400 ka) of the hydrothermal system, but probably continuing today at depth. Electron microprobe analyses of secondary layer silicate minerals in strongly propylitized samples (delta(18)O < +5.0) revealed the presence of discrete chlorite, suggesting that temperatures up to 200 to 250 degrees C were attained in the shallow levels of the system. Two zones of pervasive meteoric hydrothermal alteration, defined by concentric O-18 contours that are probably interconnected at depth, are located within the original topographic edifice of the volcano. The most intensely altered rocks within these equant zones of alteration define NNW trends that coincide with Stream valleys and with regional structural patterns. A comparison of the characteristics of the O-18-depleted zone at Brokeoff with those of more deeply eroded volcanic centers, such as the Comstock Lode mining district (Criss and Champion, 1991), permits the construction of composite O-18 cross sections through a hypothetical intact stratovolcano. At both Brokeoff and Comstock, hydrothermal fluids were strongly focused into plumelike zones of intense O-18 depletion. At Comstock, these low-O-18 plumes are associated with faults. Although major fault displacements are not observed at Brokeoff, the topographic and alteration patterns are consistent with the presence of a linear army of faults that acted as conduits for fluid flow up into the shallow levels of the volcano. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP ROSE, TP (reprint author), UNIV CALIF DAVIS, DEPT GEOL, DAVIS, CA 95616 USA. NR 52 TC 11 Z9 12 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 NOV 10 PY 1994 VL 99 IS B11 BP 21621 EP 21633 DI 10.1029/94JB02162 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500005 ER PT J AU HAGSTRUM, JT CHAMPION, DE AF HAGSTRUM, JT CHAMPION, DE TI PALEOMAGNETIC CORRELATION OF LATE QUATERNARY LAVA FLOWS IN THE LOWER EAST RIFT-ZONE OF KILAUEA VOLCANO, HAWAII SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID PACIFIC NONDIPOLE LOW; SECULAR VARIATION; DIRECTIONS; QUESTION AB Paleomagnetic data reflecting paleosecular variation (PSV) of the geomagnetic field are used to correlate individual lava flows in the lower east rift zone of Kilauea Volcano. This area has been recently mapped based on petrography, stratigraphy, soil development, and degree of weathering of the flows; eight C-14 dates also provide a framework for the relative age assignments. Site-mean directions of remanent magnetization for historic flows in this region indicate that local magnetic anomalies do not mask the PSV signal, that within-flow angular differences are generally < 5 degrees, and that temporal resolution of the paleomagnetic directions is of the order of 100 years. The paleomagnetic correlations do not conflict with the observed stratigraphic relationships, and PSV reference curves from dated lava flows and lake sediments have also been used to help determine the sequence of directional groups. Paleomagnetic grouping of flows into eruptive events indicates a different and perhaps more refined eruptive history for the lower east rift zone than implied by the geologic mapping alone. The number of individual flows based on petrographic distinctions is likely the same, but the frequency of events (including petrographically distinct flows) is apparently lower than previously thought. Flows from ridge crest vents bifurcated by the rift indicate formation of the central graben in this region after similar to 300 years ago, possibly related to the 1790 eruptions along dual fractures. RP HAGSTRUM, JT (reprint author), US GEOL SURVEY, ISOTOPE GEOL BRANCH, MAIL STOP 937, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 22 TC 27 Z9 27 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 NOV 10 PY 1994 VL 99 IS B11 BP 21679 EP 21690 DI 10.1029/94JB01852 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500010 ER PT J AU FORTE, AM WOODWARD, RL DZIEWONSKI, AM AF FORTE, AM WOODWARD, RL DZIEWONSKI, AM TI JOINT INVERSIONS OF SEISMIC AND GEODYNAMIC DATA FOR MODELS OF 3-DIMENSIONAL MANTLE HETEROGENEITY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DYNAMIC SURFACE-TOPOGRAPHY; ASPHERICAL EARTH STRUCTURE; PERIOD NORMAL-MODES; FLOW MODELS; 3-DIMENSIONAL STRUCTURE; LATERAL HETEROGENEITY; LAYERED CONVECTION; PHASE-TRANSITIONS; TOMOGRAPHY; CONSTRAINTS AB The seismic models of three-dimensional (3-D) mantle heterogeneity may be interpreted in terms of the density perturbations which drive mantle flow and thus provide important predictions of flow-related observables, such as the nonhydrostatic geoid. The current models of global-scale shear velocity heterogeneity provide reasonably good fits to the long-wavelength nonhydrostatic geoid data (60-70% variance reductions) but rather poor fits to the corresponding free-air gravity anomalies (30-40% variance reductions). This major difference is due to two factors: (1) the very different amplitude spectrum of the gravity anomalies, which is nearly flat for degrees l < 8, and (2) the relatively poor match between the individual harmonic components of the predicted and observed gravity anomalies for degrees l > 3. The largest mismatch between the pattern of predicted and observed gravity anomalies is in the southern hemisphere. This observation suggests that one reason for the poor overall match between the two fields may be that the global seismic data are not resolving sufficiently well the heterogeneity in the southern hemisphere portion of the deep mantle. In contrast, the gravity data provide accurate and geographically uniform constraints on the vertically integrated heterogeneity in the mantle. We therefore perform a series of experiments in which we simultaneously invert a large set of seismic data (which includes long-period waveforms, SS - S and ScS - S differential travel times, and normal-mode structure coefficients) and the long-wavelength gravity anomaly data. We thus determine whether it is possible to derive new 3-D heterogeneity models which satisfy both data sets. The gravity anomaly data are interpreted in the context of spherically-symmetric viscous flow models of the mantle. In these inversion experiments we test several radial viscosity and delta ln rho/delta ln upsilon profiles and thereby assess their plausibility. The joint seismic-geodynamic inversions reveal that it is indeed possible to greatly improve the fit to the free-air gravity anomalies (with variance reductions of 80-90% readily accessible) while preserving the fit to the seismic data. This improvement is achieved with some adjustment to the heterogeneity in the depth range 1500-2500 km, where the seismic data constraints appear to be weakest. The joint inversions also reveal new structures in the southern hemisphere portion of the lower mantle which apparently are not resolved by the seismic data alone. C1 HARVARD UNIV, DEPT EARTH & PLANETARY SCI, CAMBRIDGE, MA 02138 USA. US GEOL SURVEY, ALBUQUERQUE SEISMOL LAB, ALBUQUERQUE, NM 87115 USA. NR 75 TC 100 Z9 101 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 NOV 10 PY 1994 VL 99 IS B11 BP 21857 EP 21877 DI 10.1029/94JB01467 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500023 ER PT J AU REVENAUGH, J SIPKIN, SA AF REVENAUGH, J SIPKIN, SA TI MANTLE DISCONTINUITY STRUCTURE BENEATH CHINA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WAVE VELOCITY STRUCTURE; TIBETAN PLATEAU; SCS REVERBERATIONS; LATERAL HETEROGENEITY; TECTONIC IMPLICATIONS; MGSIO3 PEROVSKITE; WESTERN PACIFIC; RAYLEIGH-WAVES; SOUTHERN TIBET; BOUNDARY-LAYER AB Mantle reflectivity profiles obtained from long-period recordings of multiple-ScS reverberations from intermediate and deep-focus earthquakes surrounding China reveal remarkably sharp images of China deep structure. The Tibetan Plateau and fold belts to the north are underlain by a midlithospheric, low-velocity zone (LVZ) evidenced by coincident G (lid-LVZ boundary) and L' (base of the LVZ) reflectors and a thickened lithosphere consistent with uniform thickening as the dominant mode of north-south deformation. The mantle beneath northeastern China, Mongolia and southeastern Russia has a typically cratonic reflectivity signature with H (Hales) and deep L (Lehmann) discontinuities. The Sino-Korean Paraplatform of eastern China is a region of active extensional tectonics, as expressed by an ''oceanic'' reflectivity pattern at shallow depths (a G discontinuity at similar to 80 km), but a more continental structure below. The southern Sea of Japan, Korean Peninsula, Yellow Sea and bordering regions of the China mainland are underlain by a similar to 5.4% impedance decrease near 330 km depth that we interpret as the upper limit of dense silicate melt atop the 410-km discontinuity produced at the subduction zones to the east. Regional inversion of the reflection coefficient of the 410-km discontinuity, R(410), reveals a pronounced high beneath Mongolia and north to northwestern China which is best explained by increased upper mantle olivine content, signifying extensive basalt depletion in a tectosphere that extends below the 410-km discontinuity. A low value of R(660), associated with topographic depression of the 660-km discontinuity beneath eastern Asia is consistent with a horizontally inclined slab atop the phase transition marking the seismic discontinuity. Reflection defocusing is an alternative but requires greater than or equal to 38 km of intermediate-scale topography within the depressed region, exceeding the amplitude of the depression by a factor of 1.5-2. Either mechanism requires strong heterogeneity far west of seismically active slabs. Two lower mantle reflectors (one beneath southern Honshu, Kyushu, and the Sea of Japan; the other below Shantung province (China) and the Yellow Sea) correlate with horizontally elongated velocity anomalies in western Pacific seismic tomography models. We speculate that they may represent slabs stagnating below the 660-km discontinuity. C1 US GEOL SURVEY, DENVER, CO 80225 USA. RP REVENAUGH, J (reprint author), UNIV CALIF SANTA CRUZ, INST TECTON, CRUSTAL IMAGING LAB, SANTA CRUZ, CA 95064 USA. NR 57 TC 47 Z9 55 U1 1 U2 17 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 NOV 10 PY 1994 VL 99 IS B11 BP 21911 EP 21927 DI 10.1029/94JB01850 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500026 ER PT J AU KANAMORI, H MORI, J HARKRIDER, DG AF KANAMORI, H MORI, J HARKRIDER, DG TI EXCITATION OF ATMOSPHERIC OSCILLATIONS BY VOLCANIC-ERUPTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MOUNT PINATUBO; WAVES; RAYLEIGH AB We investigated the mechanism of atmospheric oscillations with periods of about 300 s which were observed for the 1991 Pinatubo and the 1982 El Chichon eruptions. Two distinct spectral peaks, at T = 270 and 230 s for the Pinatubo eruption and at T = 195 and 266 s for the El Chichon eruptions, have been reported; We found similar oscillations for the 1980 Mount St. Helens and the 1883 Krakatoa eruptions. To explain these observations, we investigated excitation problems for two types of idealized sources, ''mass injection'' and ''energy injection'' sources, placed in an isothermal atmosphere. In general, two modes of oscillations, ''acoustic'' and ''gravity'' modes, can be excited. For realistic atmospheric parameters, the acoustic and gravity modes have a period of 275 and 304 s, respectively. For a realistic time history of eruption, atmospheric oscillations with an amplitude of 50 to 100 Pa (0.5 to 1 mbar) can be excited by an energy injection source with a total energy of 10(17) J. This result is consistent with the observations and provides a physical basis for interpretation of atmospheric oscillations excited by volcanic eruptions. C1 US GEOL SURVEY, PASADENA, CA 91106 USA. RP KANAMORI, H (reprint author), CALTECH, SEISMOL LAB, 252-21, PASADENA, CA 91125 USA. NR 29 TC 51 Z9 51 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 NOV 10 PY 1994 VL 99 IS B11 BP 21947 EP 21961 DI 10.1029/94JB01475 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500028 ER PT J AU PELTZER, G HUDNUT, KW FEIGL, KL AF PELTZER, G HUDNUT, KW FEIGL, KL TI ANALYSIS OF COSEISMIC SURFACE DISPLACEMENT GRADIENTS USING RADAR INTERFEROMETRY - NEW INSIGHTS INTO THE LANDERS EARTHQUAKE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SEQUENCE; FIELD AB The map of the coseismic displacement field generated by interferometric processing of synthetic aperture radar (SAR) images taken before and after the June 28, 1992, Landers earthquake sequence brings new insights into the nature of deformation caused by these earthquakes. We use the interferometric map generated by Massonnet et al. (1993) to analyze the surface displacement field in the vicinity of the fault trace. Complexities in the fringe pattern near the fault reflect short-wavelength variations of the surface rupture and slip distribution, and attest to large displacement gradients. Along two sections of the fault, characteristic fringe patterns can be recognized, contrasting in density and direction with patterns observed away from the rupture. In order to understand the observed fringe patterns, we compute synthetic interferograms in three simple cases: (1) rigid-body rotations about a vertical axis, (2) about a horizontal axis (tilt), and (3) distributed, simple shear. The orientation and spatial separation of interferometric fringes predicted by these models help constrain near-field deformation and rupture parameters. Where the Kickapoo fault connects with the Homestead Valley fault, the interferogram shows a clear pattern of parallel N20 degrees W fringes separated by about 160 m. This pattern and vertical offsets measured along the Kickapoo fault suggest that the block between this fault and the Johnson Valley fault may have been tilted, down to the west. A 5-km block lifted by 1 m on one side would be tilted by an angle of 0.01 degrees (190 mu rad), producing fringes separated by about 160 m, parallel to the tilt axis. Such a tilt, parallel to a N20 degrees W direction, would account for the gradual, northward increase of the vertical slip component observed along the Kickapoo fault. This tilt may also explain the 1 m of reverse slip observed along the ''slip gap'' section of the Homestead Valley break. Between the southern end of the Johnson Valley fault and the Eureka Peak fault, where no surface rupture has been mapped, the dense pattern of fringes implies distributed shear, probably resulting from fault slip at depth. The density and direction of the fringes in the gap are consistent with a right-lateral slip of 1.2-3.8 m on a blind fault locked above the depth of 1.5-2 km. Such observations of small wavelength features in the SAR interferogram bring new insights into the near-field displacement gradient and thus on response of the uppermost crust to seismic rupture. C1 OBSERV MIDI PYRENEES, CNRS, UPR 234, F-31400 TOULOUSE, FRANCE. US GEOL SURVEY, PASADENA, CA 91106 USA. RP PELTZER, G (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010; Feigl, Kurt/E-8106-2012 OI Hudnut, Kenneth/0000-0002-3168-4797; Feigl, Kurt/0000-0002-2059-6708 NR 19 TC 34 Z9 36 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 NOV 10 PY 1994 VL 99 IS B11 BP 21971 EP 21981 DI 10.1029/94JB01888 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500031 ER PT J AU BILLS, BG CURREY, DR MARSHALL, GA AF BILLS, BG CURREY, DR MARSHALL, GA TI VISCOSITY ESTIMATES FOR THE CRUST AND UPPER-MANTLE FROM PATTERNS OF LACUSTRINE SHORELINE DEFORMATION IN THE EASTERN GREAT-BASIN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID WESTERN UNITED-STATES; MULTILAYERED HALF-SPACE; WASATCH FAULT ZONE; LAKE BONNEVILLE; RANGE PROVINCE; NORTH-AMERICA; LINE INTERFEROMETRY; STRAIN ACCUMULATION; PLATE MOTIONS; SLIP FAULTS AB The deformed shorelines of Lake Bonneville constitute a classic source of information on lithospheric elastic thickness and upper mantle viscosity. We describe and apply a new model to a recently augmented data set. New data better constrain both the complex spatio-temporal pattern of the lake load and the crustal deformation response to that load. The history of lake level fluctuations has been significantly refined and somewhat modified. This is due to both more radiocarbon dates from within the Bonneville basin and to an improved calibration of the radiocarbon timescale itself. The data which constrain the crustal deformation pattern consist of ages and shoreline elevations from several hundred points which sample three major levels of Lake Bonneville and corresponding elevations from the high stands of three smaller lakes situated to the west of Lake Bonneville. The data from the smaller lakes help elucidate the pattern of deflection which occurred beyond the edge of the big lake. The geometry of the Earth model incorporates an arbitrary number of layers overlying a half-space, and the theology of each level can accommodate an arbitrary number of Maxwell viscoelastic elements in parallel. The inverse modeling comprises three complementary approaches: for the simplest configurations, we performed a direct search of the parameter space and delineated the irregular boundary of the subspace of acceptable models. For more complex configurations, we constrained the elastic parameters to their seismically determined values and then solved for viscosity versus depth profiles by either expressing the log(viscosity) versus log(depth) profile as a series of specially constructed orthogonal polynomials, or by allowing each of 8-10 layers (plus the half-space) to have an independently determined viscosity. We found that the data do not strongly support (nor can they conclusively exclude) a more complex theology than simple Maxwell viscoelasticity. The orthogonal polynomial solution exhibits an essentially monotonic decrease in viscosity with depth. The most rapid change occurs at shallow depths, decreasing from 10(23) Pa s at 3 km to 10(20) Pa s at 30 km. The decrease is much more gradual below, with only another factor of 5 decrease between 30 and 300 km depth. The unconstrained solution exhibits a rapid decrease in viscosity with depth from 2x10(24) Pa s in the top 10 km to 4x10(17) Pa s at a depth of 40 km. A nearly isoviscous asthenospheric region extends from 40 to 150 km and is underlain by a mantle lithospheric region with increased viscosity (2x10(20) Pa s) extending from 150 to 300 km depth and by a uniform viscosity (10(19) Pa s) half-space below C1 UNIV UTAH, DEPT GEOG, LIMNEOTECTON LAB, SALT LAKE CITY, UT 84112 USA. US GEOL SURVEY, EARTHQUAKE GEOL & GEOPHYS BRANCH, MENLO PK, CA 94025 USA. RP BILLS, BG (reprint author), NASA, GODDARD SPACE FLIGHT CTR, GEODYNAM BRANCH, CODE 921, GREENBELT, MD 20771 USA. RI Bills, Bruce/C-1156-2008 NR 114 TC 79 Z9 79 U1 2 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 NOV 10 PY 1994 VL 99 IS B11 BP 22059 EP 22086 DI 10.1029/94JB01192 PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500037 ER PT J AU SASS, JH LACHENBRUCH, AH GALANIS, SP MORGAN, P PRIEST, SS MOSES, TH MUNROE, RJ AF SASS, JH LACHENBRUCH, AH GALANIS, SP MORGAN, P PRIEST, SS MOSES, TH MUNROE, RJ TI THERMAL REGIME OF THE SOUTHERN BASIN AND RANGE PROVINCE .1. HEAT-FLOW DATA FROM ARIZONA AND THE MOJAVE DESERT OF CALIFORNIA AND NEVADA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID STRIKE-SLIP FAULTS; CAJON PASS; CONDUCTIVITY; EVOLUTION; TRANSECT; WELL AB With about 150 new heat flow values, more than 200 values of heat flow are now available from the crystalline terranes of southern California, the Basin and Range Province of Arizona, and Paleozoic sedimentary rocks of the southwestern Colorado Plateau (CP). Heat flow ranges from about 5 mW m(-2) on the CP near Flagstaff, Arizona, to more than 150 mW m(-2) in the crystalline rocks bordering the Salton Trough in SE California. The heat flow pattern within this region is complex, although it correlates with regional physiographic and tectonic features. Unlike the adjacent Sierra Nevada Batholith where heat flow is a linear function of near-surface radiogenic heat production, no statistically significant correlation exists between heat flow and heat production in the study area, possibly because of its complex tectonic history, involving lateral movement of basement terranes, and relatively young heat sources and sinks of different strengths, ages, and durations. Contemporary and Neogene extensional tectonism appears to be responsible for the very high heat flow (>100 mW m(-2)) associated with the Salton Trough and its neighboring ranges, the Death Valley m fault zone and its southward extension along the eastern boundary of the Mojave block, and zones of shallow depth (<10 km) to the Curie isotherm (as inferred from aeromagnetic data) in west central Arizona. Low (<60 mW m(-2)) heat flow in the Peninsular Ranges and eastern Transverse Ranges of California may be caused by downward advection associated with subduction and compressional tectonics. Relatively low heat flow (67 +/- 4 mW m(-2)) is also associated with the main trend of metamorphic core complexes in Arizona, and the outcropping rocks in the core complexes have a low radioactive heat production (1.3 +/- 0.3 mu W m(-3)). compared to the other crystalline rocks in the region (2.1 +/- 0.2 mu W m(-3). C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. NO ARIZONA UNIV, DEPT GEOL, FLAGSTAFF, AZ 86011 USA. RP SASS, JH (reprint author), US GEOL SURVEY, 2255 N GEMINI DR, FLAGSTAFF, AZ 86001 USA. NR 88 TC 45 Z9 45 U1 2 U2 10 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 NOV 10 PY 1994 VL 99 IS B11 BP 22093 EP 22119 DI 10.1029/94JB01891 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500039 ER PT J AU LACHENBRUCH, AH SASS, JH MORGAN, P AF LACHENBRUCH, AH SASS, JH MORGAN, P TI THERMAL REGIME OF THE SOUTHERN BASIN AND RANGE PROVINCE .2. IMPLICATIONS OF HEAT-FLOW FOR REGIONAL EXTENSION AND METAMORPHIC CORE COMPLEXES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WEST-CENTRAL ARIZONA; CRUSTAL STRUCTURE; GREAT-BASIN; SOUTHEASTERN CALIFORNIA; CONTINENTAL EXTENSION; COLORADO PLATEAU; CENTRAL NEVADA; MAGMATISM; LITHOSPHERE; TECTONICS AB The average heat flow for the presently quiescent southern Basin and Range Province (82 +/- 3 mW m(-2)) is only marginally lower than that for the northern Basin and Range (92 +/- 9 mW m(-2)), even though the former has been relatively inactive over the past 10-15 m.y. This result is consistent with a broad range of simple homogeneous models for province-wide extension; the high heat flow (roughly equivalent to doubling the stable mantle contribution) can develop quickly from nonconductive processes (extension, magmatism, delamination), but the decay is a conductive process that might have little effect in the first 10-15 m.y. of quiescence. The frequently cited province-wide estimate of 100% extension (beta = 2) in the Basin and Range is consistent with the observed heat flow but not required by it. Extension models involving lithosphere thinning by delamination (and not solely by stretching), and/or magmatic additions, can provide the observed heat flow with less extension. These models are easier to reconcile with the buoyancy requirements of the present high elevation. Loss of buoyancy required by 100% extension poses special problems; either the preextensional terrain was as high as any on Earth today, or a large compensating source of buoyancy developed during the extension process. Possible candidates are magmatic contributions to the crust (which must be very large to be important in this context), trapped melt or lighter phases in the mantle, or a locally hot plume-fed upper asthenosphere. Superimposed on the regional scale extension are zones where intense local extension has removed much of the upper crust to form metamorphic core complexes. Two thermal observations might bear on their origin: (1) Relatively low heat flow (67 +/- 4 mW m(-2)) is associated with the main trend of metamorphic core complexes (MCCs) in Arizona, and (2) the outcropping rocks in the core complexes have a low radioactive heat production (1.3 +/- .3 mu W m(-3)) compared to the other crystalline rocks in the region (2.1 +/- .2 mu W m(-3)). These observations are consistent with the belief that radioactivity decreases downward in the crust and that MCCs are sites of massive unroofing. In fact, the measured heat flow low could be explained by the removal of 10-20 km of upper crustal radioactivity provided the opposing effects of transient heating from unroofing were short-lived. According to an idealized model, this would be the case if the compensating mass flow occurred in the lower crust, not in the mantle. In this sense the regional thermal results provide some support for the lower crustal return flow hypothesis for metamorphic core complexes. C1 NO ARIZONA UNIV, DEPT GEOL, FLAGSTAFF, AZ 86011 USA. US GEOL SURVEY, FLAGSTAFF, AZ 86001 USA. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 63 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 NOV 10 PY 1994 VL 99 IS B11 BP 22121 EP 22133 DI 10.1029/94JB01890 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500040 ER PT J AU FINN, C KIMURA, G SUYEHIRO, K AF FINN, C KIMURA, G SUYEHIRO, K TI INTRODUCTION TO THE SPECIAL SECTION NORTHEAST JAPAN - A CASE-HISTORY OF SUBDUCTION SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Editorial Material ID SEISMIC ZONE; ARC; ROTATION; BENEATH C1 UNIV OSAKA PREFECTURE, COLL INTEGRATED ARTS & SCI, DEPT EARTH SCI, SAKAI, OSAKA 593, JAPAN. UNIV TOKYO, OCEAN RES INST, NAKANO KU, TOKYO 164, JAPAN. RP FINN, C (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 964, DENVER, CO 80225 USA. NR 42 TC 10 Z9 10 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 NOV 10 PY 1994 VL 99 IS B11 BP 22137 EP 22145 DI 10.1029/94JB01130 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500041 ER PT J AU FINN, C AF FINN, C TI AEROMAGNETIC EVIDENCE FOR A BURIED EARLY CRETACEOUS MAGMATIC ARC, NORTHEAST JAPAN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID ISLANDS; EVOLUTION; TECTONICS; HOKKAIDO; MARGINS; BENEATH; BELT AB Positive aeromagnetic anomalies, recent drilling, and models constructed from these data delineate the plutonic roots of the Early Cretaceous Kitakami magmatic are in northeast Japan. Buried plutons, mostly offshore, produce belts of positive magnetic anomalies. These anomalies and magnetotelluric data suggest that the plutons form a batholith 70-120 km wide, nearly 800 km long, and 10-15 km thick. The batholith may mark the location of the main Kitakami are. Most of the exposed Kitakami plutons are 2-20 km in diameter; some are 3 km thick. The small plutons line up along NW trending faults; some may have been satellite vents that tapped into the magma supply of the main are. The batholithic roots of the main are now compose almost half of the modern Japan forearc basement. Steep magnetic gradients, offset anomalies, and basin stratigraphy portray extensive faulting of the Kitakami batholith during oblique subduction in the Late Cretaceous and rifting in the Miocene. The eastern boundary of the Kitakami batholith lies between 90 and 140 km west of the modern trench, much closer than the 300-km distance between the active are and trench. The Early Cretaceous forearc basin and accretionary prism may underlie the modern forearc basin east of the batholith, but clear evidence is lacking. Much of the Early Cretaceous margin, including most of its forearc therefore is missing. How the material was removed is unknown: it could have been strike-slip faulted, eroded by subduction-related processes, or both. RP FINN, C (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 964, POB 25046, DENVER, CO 80225 USA. NR 112 TC 37 Z9 37 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 NOV 10 PY 1994 VL 99 IS B11 BP 22165 EP 22185 DI 10.1029/94JB00855 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500043 ER PT J AU VONHUENE, R KLAESCHEN, D CROPP, B MILLER, J AF VONHUENE, R KLAESCHEN, D CROPP, B MILLER, J TI TECTONIC STRUCTURE ACROSS THE ACCRETIONARY AND EROSIONAL PARTS OF THE JAPAN TRENCH MARGIN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CONVERGENT MARGINS; SUBDUCTION ZONES; MECHANICS AB Structure sections across the Japan Trench from prestack depth migrated seismic data define the accretionary prism, a wedge-shaped seaward end of the continental framework, and a tectonized middle slope between them. The 10-km-wide accretionary prism is underthrust by sediment remaining with the subducted oceanic crust. Structure beneath the steep middle slope more nearly resembles the adjacent continental margin than the accreted mass. This deformed middle slope domain forms a buffer between the compliant accretionary wedge and a more rigid older continental framework. Along the plate boundary, subducted strata thicken beneath the middle and upper slopes and, where last imaged, are four times the input thickness beneath the accretionary prism. This interplate stratified layer appears to control interplate friction because the layer is imaged 45 km landward from the trench axis to 12-km depth and in that expanse, few upper plate earthquakes are recorded. Erosion of the base of the upper plate beneath the middle continental slope is indicated by margin subsidence and material flux. This erosion is concurrent with accretion at the front of the margin. C1 US GEOL SURVEY, DENVER, CO 80225 USA. RP VONHUENE, R (reprint author), CHRISTIAN ALBRECHTS UNIV KIEL, MARINE GEOSCI RES CTR, GEOMAR, WISCHLOFSTR 1-3, D-24148 KIEL, GERMANY. NR 24 TC 68 Z9 69 U1 0 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 NOV 10 PY 1994 VL 99 IS B11 BP 22349 EP 22361 DI 10.1029/94JB01198 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PR675 UT WOS:A1994PR67500054 ER PT J AU BREDEHOEFT, JD WESLEY, JB FOUCH, TD AF BREDEHOEFT, JD WESLEY, JB FOUCH, TD TI SIMULATIONS OF THE ORIGIN OF FLUID PRESSURE, FRACTURE GENERATION, AND THE MOVEMENT OF FLUIDS IN THE UINTA BASIN, UTAH SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID DEEP BRINE AQUIFERS; PALO-DURO BASIN; OIL-SHALE; HYDROCARBON GENERATION; GROUNDWATER-FLOW; HEAT-FLOW; PETROLEUM; MODEL; HYDRODYNAMICS; TEMPERATURE AB The Altamont oil field in the deep Uinta basin is known to have reservoir fluid pressures that approach lithostatic. One explanation for this high pore-fluid pressure is the generation of oil from kerogen in the Green River oil shale at depth. A three-dimensional simulation of flow in the basin was done to test this hypothesis. In the flow simulation, oil generation is included as a fluid source. The kinetics of oil generation from oil shale is a function of temperature. The temperature is controlled by (1) the depth of sediment burial and (2) the geothermal gradient. Using this conceptual model, the pressure buildup results from the trade-off between the rate of oil generation and the flow away from the source volume. The pressure increase depends primarily on (1) the rate of the oil-generation reaction and (2) the permeability of the reservoir rocks. A sensitivity analysis was performed in which both of these parameters were systematically varied. The reservoir permeability must be lower than most of the observed data for the pressure to build up to near lithostatic. The results of the simulations indicated that once oil generation was initiated, the pore pressure built up rapidly to near lithostatic. We simulated hydrofractures in that part of the system in which the pressures approach lithostatic by increasing both the horizontal and the vertical permeability by an order of magnitude. Because the simulated hydrofractures were produced by the high pore pressure, they were restricted to the Altamont field. A new flow system was established in the vicinity of the reservoir; the maximum pore pressure was limited by the least principal stress. Fluids moved vertically up and down and laterally outward away from the source of oil generation. The analysis indicated that, assuming that one is willing to accept the low values of permeability, oil generation can account for the observed high pressures at Altamont field. C1 COLORADO SCH MINES,GOLDEN,CO 80401. US GEOL SURVEY,LAKEWOOD,CO 80225. RP BREDEHOEFT, JD (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,345 MIDDLEFIELD RD,MENLO PK,CA, USA. NR 47 TC 75 Z9 86 U1 0 U2 2 PU AMER ASSOC PETROLEUM GEOLOGIST 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 NOV PY 1994 VL 78 IS 11 BP 1729 EP 1747 PG 19 WC Geosciences, Multidisciplinary SC Geology GA PQ975 UT WOS:A1994PQ97500005 ER PT J AU COLMAN, JA EDWARDS, P AF COLMAN, JA EDWARDS, P TI EXTENDING LIMITS OF POND PRODUCTION - RESPONSE SO AQUACULTURE LA English DT Letter C1 ASIAN INST TECHNOL,BANGKOK 10501,THAILAND. RP COLMAN, JA (reprint author), US GEOL SURVEY,28 LORD RD,SUITE 280,MARLBOROUGH,MA, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD NOV 1 PY 1994 VL 127 IS 2-3 BP 277 EP 278 DI 10.1016/0044-8486(94)90434-0 PG 2 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA PQ810 UT WOS:A1994PQ81000018 ER PT J AU WALDER, JS DRIEDGER, CL AF WALDER, JS DRIEDGER, CL TI RAPID GEOMORPHIC CHANGE CAUSED BY GLACIAL OUTBURST FLOODS AND DEBRIS FLOWS ALONG TAHOMA CREEK, MOUNT RAINIER, WASHINGTON, USA SO ARCTIC AND ALPINE RESEARCH LA English DT Article AB As part of a hazards-assessment study, we examined the nature and rate of geomorphic change caused by outburst floods and debris flows along Tahoma Creek, Mount Rainier, since 1967. Archival aerial photographs of the area proved to be a rich source of qualitative geomorphic information. On the basis of limited direct evidence and considerations of stream hydrology, we conclude that nearly all of these debris flows began as outburst floods from South Tahoma Glacier. The water floods transformed to debris flows by incorporating large masses of sediment in a 2-km-long channel reach where the stream has incised proglacial sediments and debris-rich, stagnant glacier ice. Comparison of topographic maps for 1970 and 1991 shows that the average sediment flux out of the incised reach has been about 2 to 4 x 10(5) m(3) a(-1), corresponding to an average denudation rate in the upper part of the Tahoma Creek drainage basin of about 20 to 40 mm a(-1), a value exceeded only rarely in basins affected by debris flows. However, little of this sediment has yet passed out of the Tahoma Creek basin. Comparison of geomorphic change at Tahoma Creek to that in two other alpine basins affected by outburst floods suggests that debris-rich stagnant ice can be an important source of sediment for debris hows as long as floods are frequent or channel slope is great. RP WALDER, JS (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 21 TC 15 Z9 15 U1 0 U2 6 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 NOV PY 1994 VL 26 IS 4 BP 319 EP 327 DI 10.2307/1551792 PG 9 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA PT769 UT WOS:A1994PT76900001 ER PT J AU PETERSON, DW HOLCOMB, RT TILLING, RI CHRISTIANSEN, RL AF PETERSON, DW HOLCOMB, RT TILLING, RI CHRISTIANSEN, RL TI DEVELOPMENT OF LAVA TUBES IN THE LIGHT OF OBSERVATIONS AT MAUNA-ULU, KILAUEA VOLCANO, HAWAII SO BULLETIN OF VOLCANOLOGY LA English DT Article DE LAVA TUBES; LAVA FLOWS; SHIELD VOLCANOS; LITTORAL LAVA TUBES; BASALT; MAUNA-ULU; KILAUEA AB During the 1969-1974 Mauna Ulu eruption on Kilauea's upper east rift zone, lava tubes were observed to develop by four principal processes: (1) flat, rooted crusts grew across streams within confined channels; (2) overflows and spatter accreted to levees to build arched roofs across streams; (3) plates of solidified crust floating downstream coalesced to form a roof; and (4) pahoehoe lobes progressively extended, fed by networks of distributaries beneath a solidified crust. Still another tube-forming process operated when pahoehoe entered the ocean; large waves would abruptly chill a crust across the entire surface of a molten stream crossing through the surf zone. These littoral lava tubes formed abruptly, in contrast to subaerial tubes, which formed gradually. All tube-forming processes were favored by low to moderate volume-rates of flow for sustained periods of time. Tubes thereby became ubiquitous within the pahoehoe flows and distributed a very large proportion of the lava that was produced during this prolonged eruption. Tubes transport lava efficiently. Once formed, the roofs of tubes insulate the active streams within, allowing the lava to retain its fluidity for a longer time than if exposed directly to ambient air temperature. Thus the flows can travel greater distances and spread over wider areas. Even though supply rates during most of 1970-1974 were moderate, ranging from 1 to 5 m3/s, large tube systems conducted lava as far as the coast, 12-13 km distant, where they fed extensive pahoehoe fields on the coastal flats. Some flows entered the sea to build lava deltas and add new land to the island. The largest and most efficient tubes developed during periods of sustained extrusion, when new lava was being supplied at nearly constant rates. Tubes can play a major role in building volcanic edifices with gentle slopes because they can deliver a substantial fraction of lava erupted at low to moderate rates to sites far down the flank of a volcano. We conclude, therefore, that the tendency of active pahoehoe flows to form lava tubes is a significant factor in producing the common shield morphology of basaltic volcanoes. RP PETERSON, DW (reprint author), US GEOL SURVEY,MS-910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 0 TC 106 Z9 106 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 NOV PY 1994 VL 56 IS 5 BP 343 EP 360 DI 10.1007/BF00326461 PG 18 WC Geosciences, Multidisciplinary SC Geology GA PU494 UT WOS:A1994PU49400004 ER PT J AU WALOSSEK, D REPETSKI, JE MULLER, KJ AF WALOSSEK, D REPETSKI, JE MULLER, KJ TI AN EXCEPTIONALLY PRESERVED PARASITIC ARTHROPOD, HEYMONSICAMBRIA-TAYLORI N-SP (ARTHROPODA-INCERTAE SEDIS, PENTASTOMIDA), FROM CAMBRIAN-ORDOVICIAN BOUNDARY BEDS OF NEWFOUNDLAND, CANADA SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article ID CRUSTACEA; SEQUENCES; NAUPLIUS; FAUNA AB A three-dimensionally and completely preserved phosphatized microfossil has been found in Cambrian - Ordovician boundary bed limestones of the Green Point Formation at Green Point, western Newfoundland, Canada. It represents a new form of larvae, previously described by D. Walossek and K.J. Muller from Upper Cambrian anthraconitic limestones (''Orsten''). These authors identified the fossils as instars of marine stem-group representatives of the ''tongue worms,'' Pentastomida. Pentastomida are parasites that today infest various land tetrapods and are presumed to represent one of the closest extant relatives of the Euarthropoda. This new fossil possesses remarkably well-preserved trunk limb vestigia and anal region. It is another example of exceptional three-dimensionally preserved, phosphatized fossils of the Orsten type that is no longer spatiotemporally restricted to the Upper Cambrian of Sweden. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP WALOSSEK, D (reprint author), UNIV BONN,INST PALEONTOL,NUSSALLEE 8,D-53115 BONN,GERMANY. NR 27 TC 29 Z9 35 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4077 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD NOV PY 1994 VL 31 IS 11 BP 1664 EP 1671 PG 8 WC Geosciences, Multidisciplinary SC Geology GA PY659 UT WOS:A1994PY65900010 ER PT J AU KREMENTZ, DG PENDLETON, GW AF KREMENTZ, DG PENDLETON, GW TI DIURNAL HABITAT USE OF AMERICAN WOODCOCK WINTERING ALONG THE ATLANTIC COAST SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID POPULATION AB The long-term decline of the American woodcock (Scolopax minor) population led us to investigate diurnal habitat use with radiotelemetry on the wintering grounds. Sites included the coastal plain of Georgia (1989 - 1991), South Carolina (1988 - 1989), and Virginia (1991 - 1992). Habitat use was not explained by age, sex, or date during the winter, but individuals used habitat differently (P < 0.05). Only shrubland was preferred at all sites in all years. Pine plantations of various ages were used according to availability, but usually less often than expected, while bottomland hardwoods and pine-hardwoods were used more often than expected. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,NATL BIOL SERV,LAUREL,MD 20708. RP KREMENTZ, DG (reprint author), UNIV GEORGIA,DB WARNELL SCH FOREST RESOURCES,SE BIOL SCI CTR,NATL BIOL SERV,SE RES GRP,ATHENS,GA 30602, USA. NR 41 TC 8 Z9 9 U1 1 U2 7 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 1994 VL 72 IS 11 BP 1945 EP 1950 DI 10.1139/z94-264 PG 6 WC Zoology SC Zoology GA QQ131 UT WOS:A1994QQ13100012 ER PT J AU SISSON, TW AF SISSON, TW TI HORNBLENDE-MELT TRACE-ELEMENT PARTITIONING MEASURED BY ION MICROPROBE SO CHEMICAL GEOLOGY LA English DT Article ID CENTRAL SIERRA-NEVADA; RARE-EARTH ELEMENTS; INTRUSIVE SUITE; COEFFICIENTS; CALIFORNIA; MAGMA; DIFFERENTIATION; PHENOCRYSTS; LIQUIDS; GENESIS AB Trace-element abundances were measured in situ by ion microprobe in five samples of hornblende and melt ranging from basaltic andesite to high-silica rhyolite. Except for one sample, for which quench overgrowth or disequilibrium is suspected, the abundance ratios show systematic inter-element and inter-sample variations, and probably approach true partition coefficients. Apparent partition coefficients are reported for La, Ce, Nd, Sm, Dy, Er, Yb, Sc, Ti, V, Cr, Sr, Y and Zr. Rare-earth elements (REE) and Y form smooth convex-upward partitioning patterns that rise to higher D-values and become increasingly convex in more evolved samples. Apparent partition coefficients for REE, Y, Ti, V and Cr can be parametrized as functions of the distribution of Ca between hornblende and melt, giving expressions to predict hornblende-melt trace-element partitioning values. These expressions are used to show that heavy REE-enriched hornblende/whole-rock REE abundance patterns in granitoids may result from partial re-equilibrium of hornblende and late-stage residual liquids rather than from anomalous partitioning values. RP SISSON, TW (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 54 TC 170 Z9 180 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD NOV 1 PY 1994 VL 117 IS 1-4 BP 331 EP 344 DI 10.1016/0009-2541(94)90135-X PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PW133 UT WOS:A1994PW13300018 ER PT J AU AUSTIN, JE SERIE, JR AF AUSTIN, JE SERIE, JR TI VARIATION IN BODY-MASS OF WILD CANVASBACK AND REDHEAD DUCKLINGS SO CONDOR LA English DT Article DE AYTHYA AMERICANA; AYTHYA VALISINERIA; DUCKLING; BROOD; BODY MASS; CANVASBACK; REDHEAD ID MALLARD DUCKLINGS; GROWTH; THERMOREGULATION; SURVIVAL AB We assessed variation in body mass of ducklings in single- and mixed-species broods of wild Canvasbacks (Aythya valisineria) and Redheads (Aythya americana) 20-50 days old. Body mass of canvasback ducklings was not affected by year and season (early vs. late hatch date) despite changes in water conditions. Mean body mass of male and female Canvasbacks did not differ in Class IIA but did differ in older age classes. Within-brood differences in body mass tended to be higher in Class IIA ducklings (6-7% of mean body mass for Canvasbacks, 9-11% in Redheads) and generally declined to 4-6% in Class IIC and older ducklings. Some within-brood differences were as high as 20-30% of mean body mass. Tests to assess sources of within-brood variation (age, sex, and season) in body mass for Canvasbacks were inconclusive. Variation within broods was generally less than that among broods for both Canvasbacks and Redheads. The lack of differences in duckling body mass between single- and mixed-species broods for any age class, sex, or species suggests that mass was not affected by interspecific brood parasitism. C1 US FISH & WILDLIFE SERV,PATUXENT ENVIRONM SCI CTR,OFF MIGRATORY BIRD MANAGEMENT,LAUREL,MD 20708. RP AUSTIN, JE (reprint author), NATL BIOL SURVEY,NO PRAIRIE SCI CTR,JAMESTOWN,ND 58401, USA. OI Austin, Jane/0000-0001-8775-2210 NR 39 TC 1 Z9 1 U1 0 U2 0 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 NOV PY 1994 VL 96 IS 4 BP 909 EP 915 DI 10.2307/1369101 PG 7 WC Ornithology SC Zoology GA PV587 UT WOS:A1994PV58700005 ER PT J AU GLEASON, JD MILLER, CF WOODEN, JL BENNETT, VC AF GLEASON, JD MILLER, CF WOODEN, JL BENNETT, VC TI PETROGENESIS OF THE HIGHLY POTASSIC 1.42 GA BARREL SPRING PLUTON, SOUTHEASTERN CALIFORNIA, WITH IMPLICATIONS FOR MIDPROTEROZOIC MAGMA GENESIS IN THE SOUTHWESTERN USA SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID WESTERN UNITED-STATES; RARE-EARTH ELEMENTS; PB ISOTOPE DATA; TRACE-ELEMENTS; PARTITION-COEFFICIENTS; VOLCANIC-ROCKS; SIERRA-NEVADA; MANTLE ORIGIN; SR ISOTOPES; ND AB Syenites from the Barrel Spring pluton were emplaced in the Early Proterozoic Mojave crustal province of southeastern California at 1.42 Ga. All rocks, even the most mafic, are highly enriched in incompatible elements (e.g. K2O 4-12 wt%, Rb 170-370 ppm, Th 12-120 ppm, La 350-1500 x chondrite, La/Yb-n 35-100). Elemental compositions require an incompatible element-rich but mafic (or ultramafic) source. Trace element models establish two plausible sources for Barrel Spring magmas: (1) LREE enriched garnet websterite with accessory apatite +/- rutile (enriched lithospheric mantle), and (2) garnet amphibolite or garnet-hornblende granulite with enriched alkali basalt composition, also with accessory apatite +/- rutile (mafic lower crust). Nd and Pb isotopic ratios do not distinguish a crust vs mantle source, but eliminate local Mojave province crust as the principal one, and indicate that generation of the enriched source occurred several hundred million years before emplacement of the Barrel Spring pluton. 1.40-1.44 Ga potassic granites are common in southeastern California, suggesting a genetic link between the Barrel Spring pluton and the granites; however, although the same thermal regime was probably responsible for producing both the granitic and syenitic magmas, elemental and isotopic compositions preclude a close relationship. Isotopic similarity of the Barrel Spring pluton to 1.40-1.44 Ga granites emplaced in the Central Arizona crustal province to the east may imply that a common component was present in the lithosphere of these generally distinct regions. C1 US GEOL SURVEY,MS 937,MENLO PK,CA 94025. AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 2601,AUSTRALIA. VANDERBILT UNIV,DEPT GEOL,NASHVILLE,TN 37235. NR 67 TC 17 Z9 17 U1 0 U2 2 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 NOV PY 1994 VL 118 IS 2 BP 182 EP 197 DI 10.1007/BF01052868 PG 16 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PW560 UT WOS:A1994PW56000006 ER PT J AU TRIBBLE, GW ATKINSON, MJ SANSONE, FJ SMITH, SV AF TRIBBLE, GW ATKINSON, MJ SANSONE, FJ SMITH, SV TI REEF METABOLISM AND ENDO-UPWELLING IN PERSPECTIVE SO CORAL REEFS LA English DT Article ID CORAL-REEF; FLORIDA ESCARPMENT; INTERSTITIAL WATER; SULFATE REDUCTION; FLAT COMMUNITIES; PHOSPHATE-UPTAKE; BARRIER-REEF; DIAGENESIS; SEDIMENTS; CHEMISTRY C1 HAWAII INST MARINE BIOL,KANEOHE,HI 96744. UNIV HAWAII,DEPT OCEANOG,HONOLULU,HI 96822. RP TRIBBLE, GW (reprint author), US GEOL SURVEY,677 ALA MOANA,SUITE 415,HONOLULU,HI 96813, USA. RI Sansone, Francis/B-9915-2013 NR 41 TC 17 Z9 17 U1 1 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD NOV PY 1994 VL 13 IS 4 BP 199 EP 201 DI 10.1007/BF00303631 PG 3 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA PV405 UT WOS:A1994PV40500002 ER PT J AU KIMBALL, BA BROSHEARS, RE BENCALA, KE MCKNIGHT, DM AF KIMBALL, BA BROSHEARS, RE BENCALA, KE MCKNIGHT, DM TI COUPLING OF HYDROLOGIC TRANSPORT AND CHEMICAL-REACTIONS IN A STREAM AFFECTED BY ACID-MINE DRAINAGE SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID IRON PHOTOREDUCTION; TRANSIENT STORAGE; SOLUTE TRANSPORT; MOUNTAIN STREAM; METAL-RICH; WATERS; ALUMINUM; KINETICS; CALIFORNIA; OXIDATION AB Experiments in St. Kevin Gulch, an acid mine drainage stream, examined the coupling of hydrologic transport to chemical reactions affecting metal concentrations. Injection of LiCl as a conservative tracer was used to determine discharge and residence time along a 1497-m reach. Transport of metals downstream from inflows of acidic, metal-rich water was evaluated based on synoptic samples of metal concentrations and the hydrologic characteristics of the stream. Transport of SO4 and Mn was generally conservative, but in the subreaches most affected by acidic inflows, transport was reactive. Both 0.1-mu m filtered and particulate Fe were reactive over most of the stream reach. Filtered Al partitioned to the particulate phase in response to high instream concentrations. Simulations that accounted for the removal of SO4, Mn, Fe, and Al with first-order reactions reproduced the steady-state profiles. The calculated rate constants for net removal used in the simulations embody several processes that occur on a stream-reach scale. The comparison between rates of hydrologic transport and chemical reactions indicates that reactions are only important over short distances in the stream near the acidic inflows, where reactions occur on a comparable time scale with hydrologic transport and thus-affect metal concentrations. C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,BOULDER,CO 80303. RP KIMBALL, BA (reprint author), US GEOL SURVEY,1745 W 1700 S,ROOM 1016,SALT LAKE CITY,UT 84104, USA. RI Bencala, Kenneth/A-6650-2010; OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 33 TC 61 Z9 62 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV PY 1994 VL 28 IS 12 BP 2065 EP 2073 DI 10.1021/es00061a014 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PP829 UT WOS:A1994PP82900016 PM 22191745 ER PT J AU YOUNG, J AF YOUNG, J TI MAKING TRAINING STICK - HOW TO CONVERT TRAINING INTO A CONTINUOUS CAREER-DEVELOPMENT PROCESS SO FISHERIES LA English DT Article RP YOUNG, J (reprint author), US FISH & WILDLIFE SERV,OFF TRAINING & EDUC,WASHINGTON,DC 20240, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD NOV PY 1994 VL 19 IS 11 BP 41 EP 41 PG 1 WC Fisheries SC Fisheries GA PQ808 UT WOS:A1994PQ80800009 ER PT J AU CYGAN, GL HEMLEY, JJ DANGELO, WM AF CYGAN, GL HEMLEY, JJ DANGELO, WM TI AN EXPERIMENTAL-STUDY OF ZINC-CHLORIDE SPECIATION FROM 300 TO 600-DEGREES-C AND 0.5 AND 2.0 KBAR IN BUFFERED HYDROTHERMAL SOLUTIONS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SUPERCRITICAL ELECTROLYTE-SOLUTIONS; THERMODYNAMIC PROPERTIES; ACTIVITY-COEFFICIENTS; BISULFIDE COMPLEXES; SOLUBILITY; 350-DEGREES-C; SPHALERITE; STABILITY; STANDARD; MOLAL AB The solubility of sphalerite (ZnS) was measured in KCl-HCl-H2O solutions at 300-600-degrees-C and 0.5-2.0 kbar. The silicate assemblage K-feldspar-muscovite (or andalusite)-quartz was used to buffer the solution to acid conditions, resulting in the total solubility reaction [GRAPHICS] A computer retrieval technique was used to derive average chloride ligand numbers for chlorozinc species at 0.25-2.0 molal total chloride. This technique mathematically solves for the average ligand number using a series of pertinent chemical relations at P and T. Mono- and di-chlorozinc species were found to predominate throughout the pressure-temperature-composition range investigated. The logarithms of the first and second dissociation constants for ZnCl2-degrees were evaluated over the P-T range; for example, at 1 kbar, the values -0.41 and -1.42 were computed for the logarithm of the first dissociation constant, while -7.62 and -10.57 were computed for the logarithm of the second dissociation constant, for 400 and 500-degrees-C, respectively. Results are compared to past studies conducted at subcritical conditions and differ in that we find no evidence for more highly coordinated chloro-zinc species except possibly for ZnCl3- at 600-degrees-C, 1 and 2 kbar. Our results are consistent with electrostatic theory, which favors lower charged to neutral molecules in low dielectric-constant media. RP CYGAN, GL (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 36 TC 21 Z9 22 U1 0 U2 5 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 1994 VL 58 IS 22 BP 4841 EP 4855 DI 10.1016/0016-7037(94)90215-1 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PU996 UT WOS:A1994PU99600003 ER PT J AU YOU, CF MORRIS, JD GIESKES, JM ROSENBAUER, R ZHENG, SH XU, X KU, TL BISCHOFF, JL AF YOU, CF MORRIS, JD GIESKES, JM ROSENBAUER, R ZHENG, SH XU, X KU, TL BISCHOFF, JL TI MOBILIZATION OF BERYLLIUM IN THE SEDIMENTARY COLUMN AT CONVERGENT MARGINS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID YOUNG VOLCANIC-ROCKS; ISLAND-ARC MAGMAS; SUBDUCTION ZONES; ISOTOPE SYSTEMATICS; GEOCHEMICAL CYCLE; BASALT MAGMAS; MANTLE WEDGE; BE-10; LAVAS; CONSTRAINTS AB Studies of Be distributions in subduction zone sediments will help to understand questions regarding the enrichments of cosmogenic Be-10 in arc volcanic rocks. Analyses of Be-10 and Be-9 in sediments of Ocean Drilling Program Site 808, Nankai Trough and Be-9 in porewaters of Site 808 and Sites 671 and 672, Barbados ridge complex, show significant decreases in solid phase Be-10 and large increases of porewater Be-9 at the location of the decollement zone and below or at potential flow conduits. These data imply the potential mobilization of Be during pore fluid expulsion upon sediment burial. Experiments involving reaction between a decollement sediment and a synthetic NaCl-CaCl2 solution at elevated pressure and temperatures were conducted in an attempt to mimic early subduction zone processes. The results demonstrate that Be is mobilized under elevated pressure and temperature with a strong pH dependence. The Be mobilization provides an explanation of Be-10 enrichment in arc volcanic rocks and supports the argument of the importance of the fluid processes in subduction zones at convergent margins. C1 WASHINGTON UNIV,DEPT EARTH & PLANETARY PHYS,ST LOUIS,MO 63130. UNIV SO CALIF,DEPT GEOL SCI,LOS ANGELES,CA 90089. US GEOL SURVEY,MENLO PK,CA 94025. CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,WASHINGTON,DC 20015. UNIV CALIF IRVINE,IRVINE,CA 92717. RP YOU, CF (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 60 TC 22 Z9 22 U1 1 U2 9 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 1994 VL 58 IS 22 BP 4887 EP 4897 DI 10.1016/0016-7037(94)90219-4 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PU996 UT WOS:A1994PU99600007 ER PT J AU LUDWIG, KR TITTERINGTON, DM AF LUDWIG, KR TITTERINGTON, DM TI CALCULATION OF (230)TH/U ISOCHRONS, AGES, AND ERRORS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID TOTAL-SAMPLE DISSOLUTION; IMPURE CARBONATES; SERIES AB If analytical errors are responsible for the scatter of points on a Th-230-U-234-U-238 isochron diagram, the isochron should be fitted by a technique that (1) weights the points according to their analytical errors and error correlations, and (2) either takes into account the presence of some of the same data in two coupled XY isochrons or (equivalently) uses a single, three-dimensional XYZ isochron. A method based on maximum-likelihood estimation is presented that fulfills these requirements, and the relevant equations for errors in age and initial U-234/U-238 are given. Equations for estimating the necessary isotope-ratio errors and error-correlations for both alpha-spectrometric and mass-spectrometric data are also developed. C1 UNIV GLASGOW,DEPT STAT,GLASGOW G12 8QW,SCOTLAND. RP LUDWIG, KR (reprint author), US GEOL SURVEY,MAIL STOP 963,DENVER,CO 80225, USA. NR 22 TC 137 Z9 141 U1 0 U2 9 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 1994 VL 58 IS 22 BP 5031 EP 5042 DI 10.1016/0016-7037(94)90229-1 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PU996 UT WOS:A1994PU99600017 ER PT J AU SEEWALD, JS SEYFRIED, WE SHANKS, WC AF SEEWALD, JS SEYFRIED, WE SHANKS, WC TI VARIATIONS IN THE CHEMICAL AND STABLE-ISOTOPE COMPOSITION OF CARBON AND SULFUR SPECIES DURING ORGANIC-RICH SEDIMENT ALTERATION - AN EXPERIMENTAL AND THEORETICAL-STUDY OF HYDROTHERMAL ACTIVITY AT GUAYMAS BASIN, GULF OF CALIFORNIA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EAST PACIFIC RISE; 500 BARS; THERMAL DECARBOXYLATION; SOUTHERN TROUGH; HOT SPRINGS; SEAWATER; BASALT; GEOCHEMISTRY; CONSTRAINTS; CHEMISTRY AB Organic-rich diatomaceous ooze was reacted with seawater and a Na-Ca-K-Cl fluid of seawater chlorinity at 325-400-degrees-C, 400-500 bars, and fluid/sediment mass ratios of 1.56-2.35 to constrain factors regulating the abundance and stable isotope composition of C and S species during hydrothermal alteration of sediment from Guaymas Basin, Gulf of California. Alteration of inorganic and organic sedimentary components resulted in extensive exchange reactions, the release of abundant H2S, CO2, CH4, and C(organic) to solution, and recrystallization of the sediment to an assemblage containing albitic plagioclase, quartz, pyrrhotite, and calcite. The deltaS-34CDT values of dissolved H2S varied from -10.9 to +4.3 parts per thousand during seawater-sediment interaction at 325 and 400-degrees-C and from -16.5 to -9.0 parts per thousand during Na-Ca-K-Cl fluid-sediment interaction at 325 and 375-degrees-C. In the absence of seawater SO4, H2S is derived from both the transformation of pyrite to pyrrhotite and S released during the degradation of organic matter. In the presence of seawater SO4, reduction of SO4 contributes directly to H2S production. Sedimentary organic matter acts as the reducing agent during pyrite and SO4 reduction. Requisite acidity for the reduction of SO4 is provided by Mg fixation during early-stage sediment alteration and by albite and calcite formation in Mg-free solutions. Organically derived CH4 was characterized by deltaC-13PDB values ranging between -20.8 and -23.1 parts per thousand, whereas deltaC-13PDB values for dissolved C(organic) ranged between -14.8 and -17.7 parts per thousand. Mass balance calculations indicate that deltaC-13 values for organically derived CO2 were greater-than-or-equal-to -14.8 parts per thousand. Residual solid sedimentary organic C showed small (less-than-or-equal-to 0.7 parts per thousand) depletions in C-13 relative to the starting sediment. The experimental results are consistent with the isotopic and chemical composition of natural hydrothermal fluids and minerals at Guaymas Basin and permit us to better constrain sources and sinks for C and S species in subseafloor hydrothermal systems at sediment-covered spreading centers. Our data show that the sulfur isotope composition of hydrothermal sulfide minerals in Guaymas Basin can be explained by derivation of S from diagenetic sulfide and seawater sulfate. Basaltic S may also contribute to hydrothermal sulfide precipitates but is not required to explain their isotopic composition. Estimates of seawater/sediment mass ratios based on sulfur isotopic composition of sulfide minerals and the abundance of dissolved NH3 in vent fluids range from 3-29 during hydrothermal circulation. Sources of C in Guaymas Basin hydrothermal fluids include thermal degradation of organic matter, bacteriogenic methane production, and dissolution of diagenetic carbonate. C1 UNIV MINNESOTA,DEPT GEOL & GEOPHYS,MINNEAPOLIS,MN 55455. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP SEEWALD, JS (reprint author), WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543, USA. NR 70 TC 45 Z9 45 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 NOV PY 1994 VL 58 IS 22 BP 5065 EP 5082 DI 10.1016/0016-7037(94)90232-1 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PU996 UT WOS:A1994PU99600020 ER PT J AU HENRY, CD KUNK, MJ MCINTOSH, WC AF HENRY, CD KUNK, MJ MCINTOSH, WC TI AR-40/AR-39 CHRONOLOGY AND VOLCANOLOGY OF SILICIC VOLCANISM IN THE DAVIS MOUNTAINS, TRANS-PECOS TEXAS SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID SOUTHWESTERN NEW-MEXICO; SAN-JUAN-MOUNTAINS; ION MICROPROBE; MAGMA CHAMBERS; IGNIMBRITES; EVOLUTION; STRESS; FIELD; GEOCHRONOLOGY; CONSTRAINTS AB Field studies and Ar-40/Ar-39 dating reveal that silicic volcanism in the Davis Mountains part of the Trans-Pecos Texas volcanic field occurred in six episodes at 0.3 m.y. intervals between 36.8 and 35.3 Ma. Additionally, two groups of silicic intrusions were emplaced at 34.6 and 32.8 Ma. This episodicity is similar to that determined for volcanic fields dominated by ash-flow tuffs, yet voluminous, extensive silicic lavas are considerably more abundant than tuffs in the Davis Mountains, by number of hows and by volume. The preponderance of voluminous silicic lavas over tuffs most likely reflects low water contents and high temperatures of the alkalic and commonly peralkaline Davis Mountains magmas. The earliest episode, at 36.8 Ma, included a widespread and voluminous (possibly >1,000 km(3)) suite of rhyolite and quartz trachyte lavas, several rhyolite domes, and a strongly rheomorphic, peralkaline ash-flow tuff erupted from a caldera in the northern Davis Mountains. The lava suite extends well beyond the Davis Mountains. Silicic lavas of all episodes probably erupted from widespread, fissure vents. The 36.5 Ma episode consisted of rhyolite to quartz trachyte lavas, also extensive and voluminous (similar to 200 km(3)). The 36.3 Ma episode consisted of rhyolite to trachyte tuffs and lavas erupted from a central vent volcano in the southern Davis Mountains. The 35.9 Ma episode consisted of a single, moderately large (similar to 50 km(3)) rhyolite lava and a small-volume ashflow tuff erupted from a caldera in the western Davis Mountains. Rocks emplaced during the 35.6 Ma episode were also rhyolites, including an enigmatic rock that may be strongly rheomorphic ash-flow tuff or a combination of tuff and lava, followed by definite lavas. The 35.3 Ma episode consisted of two ash-flow tuffs, one of which is strongly rheomorphic, and additional voluminous rhyolite lavas (similar to 120 km(3)). The rheomorphic tuff erupted from a caldera in the southwestern Davis Mountains. The source of the other Buff is probably in the western Davis Mountains. Intermediate and mafic rocks are minor, except around the southeastern flank of the Davis Mountains, where basalt is abundant, Mafic lavas erupted only during gaps in the silicic activity and on the flanks of the Davis Mountains. Nevertheless, basaltic magma probably drove the silicic magmatism, either by differentiation or by crustal melting, and was present throughout the time of Davis Mountains activity but could not penetrate the low-density silicic magma chambers until they cooled and solidified. The time required for cooling and solidification appears to be 0.1-0.2 m.y. C1 UNIV TEXAS, BUR ECON GEOL, AUSTIN, TX 78713 USA. US GEOL SURVEY, RESTON, VA 22092 USA. NEW MEXICO BUR MINES & MINERAL RESOURCES, SOCORRO, NM 87801 USA. NR 71 TC 14 Z9 14 U1 4 U2 9 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 NOV PY 1994 VL 106 IS 11 BP 1359 EP 1376 DI 10.1130/0016-7606(1994)106<1359:AACAVO>2.3.CO;2 PG 18 WC Geosciences, Multidisciplinary SC Geology GA PP792 UT WOS:A1994PP79200001 ER PT J AU HILDRETH, W LANPHERE, MA AF HILDRETH, W LANPHERE, MA TI POTASSIUM-ARGON GEOCHRONOLOGY OF A BASALT-ANDESITE-DACITE ARC SYSTEM - THE MOUNT ADAMS VOLCANIC FIELD, CASCADE RANGE OF SOUTHERN WASHINGTON SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID MAGMATISM AB High-precision K-Ar dating and detailed mapping have established an eruptive chronology for a Cascade stratovolcano and its surrounding array of coeval basaltic centers. Mount Adams is a 200 km(3) andesitic cone that stands at the center of a coeval 1250 km(2) Quaternary volcanic field that contains >60 discrete vents. K-Ar ages were measured for 74 samples from 63 of the 136 volcanic units defined in the course of the mapping. Within analytical error, there are no discrepancies between K-Ar ages and stratigraphic sequence. Major activity began in the area ca. 940 ka, and inception of the central stratovolcano took place at ca. 520 ka. A plot of cumulative volume erupted versus time shows that between 940 and 520 ka the eruptive rate was <0.04 km(3)/k.y. and similar to 80% of the products were basaltic. Andesites are volumetrically dominant and were emplaced in three main cone-building episodes centered at 500, 450, and 30 ka-at eruptive rates of 1.6-5 km(3)/k.y. At a lower rate of 0.05-0.1 km(3)/ky., the magmatic system remained almost continuously active between the main pulses-although breaks in activity as long as 30 ky. are permitted by the K-Ar data. Andesitic-dacitic activity in the focal region and dominantly basaltic activity on the periphery have coexisted for 520 ky., and their products are interstratified. The last main episode of cone construction occurred ca. 40-10 ka, the oldest andesite identifiably derived from within the present-day edifice having an age of 33 +/- 14 ka. Andesites forming the south-summit rim and the true summit have ages of 13 +/- 8 ka and 15 +/- 8 ka, respectively. The time-volume-composition data bear upon several fundamental questions concerning the long-term behavior of are volcanoes. Stratovolcanoes commonly grow in spurts but can stay active between the widely spaced episodes of peak productivity. Large stratocone systems may remain active for half a million years. Subdivision of complex stratovolcanoes into eruptive or constructional ''stages'' without detailed mapping, geochronology, and compositional data should be treated skeptically. Discussion of volumetric eruptive rates can be misleading without an adequate time scale. Stratovolcanoes need never develop large upper-crustal magma chambers. Basalt erupts peripherally, but its ascent is suppressed beneath stratovolcanoes by deep-crustal domains of magma storage and hybridization that form where concentrated injection of basalt amplifies crustal melting. RP HILDRETH, W (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 30 TC 95 Z9 95 U1 0 U2 6 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 NOV PY 1994 VL 106 IS 11 BP 1413 EP 1429 DI 10.1130/0016-7606(1994)106<1413:PAGOAB>2.3.CO;2 PG 17 WC Geosciences, Multidisciplinary SC Geology GA PP792 UT WOS:A1994PP79200004 ER PT J AU BISCHOFF, JL JULIA, R SHANKS, WC ROSENBAUER, RJ AF BISCHOFF, JL JULIA, R SHANKS, WC ROSENBAUER, RJ TI KARSTIFICATION WITHOUT CARBONIC-ACID - BEDROCK DISSOLUTION BY GYPSUM-DRIVEN DEDOLOMITIZATION SO GEOLOGY LA English DT Article ID AQUIFER AB Aggressive karstification can take place where dolomite and gypsum are in contact with the same aquifer. Gypsum dissolution drives the precipitation of calcite, thus consuming carbonate ions released by dolomite. Lake Banyoles, in northeastern Spain, is a karst lake supplied by sublacustrine springs, and karstic collapse is occurring in the immediate vicinity of the lake. Lake water is dominated by Mg-Ca and SO4-HCO3, and is supersaturated with calcite that is actively accumulating in lake sediments. Water chemistry, sulfur isotope composition, local stratigrapy, and mass-balance modeling suggest that the primary karst-forming process at Lake Banyoles is dedolomitization of basement rocks driven by gypsum dissolution. Karstification takes place along the subsurface contact between the gypsiferous Beuda Formation and the dolomitic Perafita Formation. This process is here recognized for the first time to cause karstification on a large scale; this is significant because it proceeds without the addition of soil-generated carbonic acid. Gypsum-driven dedolomitization may be responsible for other karstic systems heretofore attributed to soil-generated carbonic acid. C1 INST GEOL JAUME ALMERA,E-08028 BARCELONA,SPAIN. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP BISCHOFF, JL (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 22 TC 63 Z9 66 U1 1 U2 10 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 1994 VL 22 IS 11 BP 995 EP 998 DI 10.1130/0091-7613(1994)022<0995:KWCABD>2.3.CO;2 PG 4 WC Geology SC Geology GA PP790 UT WOS:A1994PP79000009 ER PT J AU BROWN, KM BEKINS, B CLENNELL, B DEWHURST, D WESTBROOK, GK AF BROWN, KM BEKINS, B CLENNELL, B DEWHURST, D WESTBROOK, GK TI HETEROGENEOUS HYDROFRACTURE DEVELOPMENT AND ACCRETIONARY FAULT DYNAMICS - REPLY SO GEOLOGY LA English DT Note C1 US GEOL SURVEY,MENLO PK,CA 94025. UNIV LEEDS,DEPT EARTH SCI,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND. UNIV NEWCASTLE UPON TYNE,FOSSIL FUELS & ENVIRONM GEOCHEM POSTGRAD INST,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND. UNIV BIRMINGHAM,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RP BROWN, KM (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 3 TC 1 Z9 1 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 NOV PY 1994 VL 22 IS 11 BP 1053 EP 1054 PG 2 WC Geology SC Geology GA PP790 UT WOS:A1994PP79000027 ER PT J AU WAYTHOMAS, CF JARRETT, RD AF WAYTHOMAS, CF JARRETT, RD TI FLOOD GEOMORPHOLOGY OF ARTHURS-ROCK GULCH, COLORADO - PALEOFLOOD HISTORY SO GEOMORPHOLOGY LA English DT Article ID DEBRIS FLOWS; FRONT RANGE; ORIENTATION; CALIFORNIA; SEDIMENTS; FABRICS AB Episodic late Quaternary flooding is recorded by bouldery deposits and slackwater sediments along Arthurs Rock Gulch, an ephemeral stream west of Fort Collins, Colorado. Flood deposits consist of individual granodiorite and pegmatite boulders, boulder bars, and coarse overbank sediment that rest on erosional terrace segments along the channel. We identified evidence for at least five floods in the lower two thirds of the 1.84 km(2) drainage basin. Flood deposits are differentiated by their position above the active channel, weathering characteristics, degree of boulder burial by colluvium, amount of lichen cover, and position with respect to terrace and colluvial deposits. Age estimates for the flood deposits are based on radiocarbon dating, tree-ring analyses, and relative-age criteria from four sites in the basin. At least two floods occurred in the last 300 years; a third flood is at least 5000 years old, but likely younger than 10,000 yr BP; and the two oldest floods occurred at least 40,000 years BP. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP WAYTHOMAS, CF (reprint author), US GEOL SURVEY,4230 UNIV DR,SUITE 201,ANCHORAGE,AK, USA. NR 58 TC 12 Z9 15 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD NOV PY 1994 VL 11 IS 1 BP 15 EP 40 DI 10.1016/0169-555X(94)90040-X PG 26 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA QC771 UT WOS:A1994QC77100002 ER PT J AU LOCKNER, DA BYERLEE, JD AF LOCKNER, DA BYERLEE, JD TI DILATANCY IN HYDRAULICALLY ISOLATED FAULTS AND THE SUPPRESSION OF INSTABILITY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GRANITE; GOUGE; EARTHQUAKES; COMPACTION; FRICTION; ZONES; FLOW; SLIP AB Laboratory studies have shown that consolidated fault gouge dilates in response to an increase in the rate of shearing. During the period of accelerating slip that characterizes the onset of an instability, or earthquake, on a fault containing consolidated, fluid-saturated gouge, the accompanying dilatancy will result in a reduction in pore fluid pressure and an increase in effective normal stress. We report laboratory observations of a 3% drop in pore pressure per decade increase in sliding rate of quartz gouge between granite fault surfaces. This dilatancy strengthening is greater than intrinsic rate-weakening observed for dry gouge and can play an important role in earthquake nucleation. RP LOCKNER, DA (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 19 TC 37 Z9 37 U1 0 U2 3 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 1 PY 1994 VL 21 IS 22 BP 2353 EP 2356 DI 10.1029/94GL02366 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PQ432 UT WOS:A1994PQ43200004 ER PT J AU MOENCH, AF AF MOENCH, AF TI SPECIFIC YIELD AS DETERMINED BY TYPE-CURVE ANALYSIS OF AQUIFER-TEST DATA SO GROUND WATER LA English DT Article ID UNCONFINED AQUIFER; DELAYED DRAINAGE; SATURATED FLOW; WATER-TABLE; SAND AB Type-curve analysis of water-table aquifer pumping-test data has often resulted in values of specific yield that are unrealistically low when compared with values obtained by volume-balance calculations. It has been suggested that such values are the result of inadequate representation of drainage processes in the unsaturated zone. The commonly used analytical solution developed by Neuman for a homogeneous, water-table aquifer assumes that the drainage of pores in the zone above the water table due to lowering of the water table occurs instantaneously. Published pumping-test data from three relatively homogeneous, unconsolidated, granular aquifers with significantly different hydraulic conductivities are used to show that type-curve analysis based on the Neuman model will result in estimates of specific yield that agree with volume-balance calculations, provided that established procedures are followed. These involve the use of composite plots of drawdown observed at more than one location and inclusion of effects of partial penetration. Noninstantaneous drainage of pores in the unsaturated zone accounts for the finding that both type-curve analysis and volume-balance calculations yield values of specific yield that are slightly less than those obtained from laboratory column-drainage experiments. It may also account for a slight underestimation of vertical hydraulic conductivity as obtained by type-curve analysis. RP MOENCH, AF (reprint author), US GEOL SURVEY,WRD,345 MIDDLEFIELD RD,MAIL STOP 496,MENLO PK,CA 94025, USA. NR 35 TC 52 Z9 52 U1 0 U2 6 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1994 VL 32 IS 6 BP 949 EP 957 DI 10.1111/j.1745-6584.1994.tb00934.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA PP802 UT WOS:A1994PP80200008 ER PT J AU MOODY, JA MEADE, RH AF MOODY, JA MEADE, RH TI EVALUATION OF THE METHOD OF COLLECTING SUSPENDED SEDIMENT FROM LARGE RIVERS BY DISCHARGE-WEIGHTED PUMPING AND SEPARATION BY CONTINUOUS-FLOW CENTRIFUGATION SO HYDROLOGICAL PROCESSES LA English DT Article DE FLUVIAL SUSPENDED SEDIMENT; SUSPENDED SEDIMENT SAMPLING; CONTINUOUS-FLOW CENTRIFUGATION; PARTICLE SIZE AB A method for collecting suspended sediment samples has been developed that pumps a discharge-weighted volume of water from fixed depths at four to 40 locations across a river and separates the suspended sediment in the sample using a continuous-flow centrifuge. The efficacy of the method is evaluated by comparing the particle size distributions of sediment collected by the discharge-weighted pumping method with the particle size distributions of sediment collected by depth integration and separated by gravitational settling. The pumping method was found to undersample the suspended sand sized particles (> 63 mum) but to collect a representative sample of the suspended silt and clay sized particles (< 63 mum). The centrifuge separated the silt and clay sized particles (< 63 mum) into three fractions. Based on the average results of processing 17 samples from the Mississippi River and several of its large tributaries in 1990, about 10% of the silt and clay sized material was trapped in a centrifuge bowl-bottom sealing unit containing the nozzle and consisted of mostly medium and coarse silt from 16 to 63 mum. About 74% was retained on a Teflon liner in the centrifuge bowl and consisted of sizes from 0.1 to 63 mum. About 9% was discharged from the centrifuge in the effluent and was finer than 0.1 mum. About 7% was lost during the processes of removing the wet sediment fractions from the centrifuge, drying and weighting. The success of the discharge-weighted pumping method depends on how homogeneously the silt and clay sized particles (< 63 mum) are distributed in the vertical direction in the river. The degree of homogeneity depends on the composition and degree of aggregation of the suspended sediment particles. RP MOODY, JA (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 413,BOX 25046,LAKEWOOD,CO 80225, USA. NR 0 TC 13 Z9 13 U1 0 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD NOV-DEC PY 1994 VL 8 IS 6 BP 513 EP 530 DI 10.1002/hyp.3360080603 PG 18 WC Water Resources SC Water Resources GA PW399 UT WOS:A1994PW39900002 ER PT J AU KARGEL, JS KIRK, RL FEGLEY, B TREIMAN, AH AF KARGEL, JS KIRK, RL FEGLEY, B TREIMAN, AH TI CARBONATE SULFATE VOLCANISM ON VENUS SO ICARUS LA English DT Review ID RADAR REFLECTIVITY; OLDOINYO-LENGAI; MAGELLAN DATA; SILICATE LIQUIDS; SURFACE; EMPLACEMENT; CHANNELS; EQUILIBRIA; VENERA; RIVER AB Venusian canali, outflow channels, and associated volcanic deposits resemble fluvial landforms more than they resemble volcanic features on Earth and Mars. Some canali have meandering habits and features indicative of channel migration that are very similar to meandering river channels and flood plains on Earth, venusian outflow channels closely resemble water-carved outflow channels on Mars and the Channeled Scabland in Washington, collapsed terrains at the sources of some venusian channels resemble chaotic terrains at the sources of martian outflow channels, venusian lava deltas are similar to bird's-foot deltas such as the Mississippi delta, and venusian valley networks indicate sapping. The depositional fluvial-type features (deltas, braided bars, and channeled plains) are generally among the smoothest terrains at the Magellan radar wavelength (12.6 cm) on Venus. These features suggest the involvement of an unusual lava, unexpected processes, and/or extraordinary eruption conditions. Possibly the lava was an ordinary silicate lava such as basalt or a less common type of silicate lava, and conditions unique to Venus or to those particular eruptions may have caused an unusual volcanological behavior. We have developed the alternative possibility that the lava had a water-like theology and a melting point slightly greater than Venus' surface temperature, thus accounting for the unusual behavior of the lava. Unlike silicate lavas, some carbonatites (including carbonate-sulfate-rich liquids) have these properties; thus they can flow great distances while retaining a high fluidity, significant mechanical erosiveness, and substantial capacity to transport and deposit sediment. Venusian geochemistry and petrology are consistent with extensive eruptions of carbonatite lavas, which could have crustal and/or mantle origins. Venus' atmosphere (especially CO2, HCl, and HF abundances) and rocks may be in local chemical equilibrium, which suggests that the upper crust contains large amounts of calcite, anhydrite, and other salts. Chemical analyses indicate, according to some models, that Venusian rocks may contain 4-19% calcite and anhydrite. Mixtures of crustal salts could melt at temperatures a few tens to a few hundred Kelvins higher than Venus' surface temperature; hence, melting may be induced by modest endogenetic or impact heating. Salts may have many of the same geologic roles on Venus as water and ice have on Mars. A molten salt (carbonatite) ''aquifer'' may exist beneath a few hundred meters to several kilometers of solidified salt-rich ''permafrost.'' Many geologic features can be explained by carbonatite magmatism: (1) impact melting of crustal salts can explain crater outflows, (2) small, sustained eruptions from molten salt aquifers can explain sapping valleys, (3) large, sustained eruptions may explain canali and their flood plans, and (4) catastrophic outbursts may have formed outflow channels and chaotic terrain. Landforms created by carbonate-rich lavas would be thermally stable on Venus' surface, though some minerals may weather to other solid substances. (C) 1994 Academic Press, Inc. C1 WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130. LUNAR & PLANETARY INST,HOUSTON,TX 77058. RP KARGEL, JS (reprint author), US GEOL SURVEY,2555 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 143 TC 51 Z9 51 U1 1 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 NOV PY 1994 VL 112 IS 1 BP 219 EP 252 DI 10.1006/icar.1994.1179 PG 34 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA QC943 UT WOS:A1994QC94300015 ER PT J AU PERRY, CA AF PERRY, CA TI SOLAR-IRRADIANCE VARIATIONS AND REGIONAL PRECIPITATION FLUCTUATIONS IN THE WESTERN USA SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE SOLAR WEATHER RELATIONS; DROUGHT ANALYSIS; ANNUAL PRECIPITATION VARIABILITY; USA; PACIFIC OCEAN ID SEA-SURFACE TEMPERATURE; MODEL; OCEAN AB Changes in total solar irradiance can be linked to changes in regional precipitation. A possible mechanism responsible for this linkage begins with the absorption of varying amounts of solar energy by the tropical oceans, which creates ocean temperature anomalies. These anomalies are then transported by major ocean currents to locations where the stored energy is released into the atmosphere, thereby altering atmospheric pressure and moisture patterns, which can ultimately affect regional precipitation. Correlation coefficients between annual differences in empirically modelled solar-irradiance variations and annual State-divisional precipitation in the USA for the period 1950-1988 were computed with lag times of 0 to 7 years. The most significant correlations occur in the Pacific North-west, with a lag time of 4 years, which is approximately equal to the travel time of water within the Pacific gyre from the western tropical Pacific Ocean to the Gulf of Alaska. Precipitation in the Desert South-west correlates significantly with solar irradiance lagged 3 and 5 years, which suggests a link with ocean-water temperature anomalies transported by the Equatorial Counter Current as well as the North Pacific gyre. With the correlations obtained, droughts coincide with periods of negative irradiance differences (dry high-pressure development), and wet periods coincide with periods of positive differences (moist low-pressure development). RP PERRY, CA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,LAWRENCE,KS 66049, USA. NR 17 TC 16 Z9 18 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV PY 1994 VL 14 IS 9 BP 969 EP 983 DI 10.1002/joc.3370140903 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PX847 UT WOS:A1994PX84700002 ER PT J AU REID, ME AF REID, ME TI A PORE-PRESSURE DIFFUSION-MODEL FOR ESTIMATING LANDSLIDE-INDUCING RAINFALL SO JOURNAL OF GEOLOGY LA English DT Note ID INTENSITY; MOVEMENT AB Many types of landslide movement are induced by large rainstorms, and empirical rainfall intensity/duration thresholds for initiating movement have been determined for various parts of the world. In this paper, I present a simple pressure diffusion model that provides a physically based hydrologic link between rainfall intensity/duration at the ground surface and destabilizing pore-water pressures at depth. The model approximates rainfall infiltration as a sinusoidally varying flux over time and uses physical parameters that can be determined independently. If destabilizing pore pressures can be estimated, then the model enables the development of a stability criterion defining destabilizing rainfall intensity/duration conditions. Using a comprehensive data set from an intensively monitored landslide, I demonstrate that the model is capable of distinguishing movement-inducing rainstorms. RP REID, ME (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 998,MENLO PK,CA 94025, USA. NR 28 TC 37 Z9 39 U1 2 U2 14 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0022-1376 J9 J GEOL JI J. Geol. PD NOV PY 1994 VL 102 IS 6 BP 709 EP 717 PG 9 WC Geology SC Geology GA PQ940 UT WOS:A1994PQ94000007 ER PT J AU WALKER, JF AF WALKER, JF TI METHODS FOR MEASURING DISCHARGE UNDER-ICE COVER SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Note RP WALKER, JF (reprint author), US GEOL SURVEY,6417 NORMANDY LANE,MADISON,WI 53719, USA. NR 4 TC 2 Z9 4 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS 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 NOV PY 1994 VL 120 IS 11 BP 1327 EP 1336 DI 10.1061/(ASCE)0733-9429(1994)120:11(1327) PG 10 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA PM779 UT WOS:A1994PM77900007 ER PT J AU OLIVER, WA SORAUF, JE AF OLIVER, WA SORAUF, JE TI BRANCHING HELIOPHYLLUM (DEVONIAN RUGOSE CORALS) FROM NEW-YORK AND OHIO SO JOURNAL OF PALEONTOLOGY LA English DT Article AB Solitary species of Heliophyllum are the most common form of the genus but branching and massive colonies do occur, especially in Middle Devonian strata of eastern North America. Heliophyllum delicatum n. sp. offsets laterally and has a dendroid, broad bushy growth form. The species is known only from western and west-central New York and appears to be limited to the lower part of the Deep Run Shale Member of the Moscow Formation (middle Givetian); specimens are common within this restricted geographic and stratigraphic range. The skeleton of H. delicatum was poorly designed for the common coral environments of the Devonian, but seems to have been well adapted to muddy, carbonate-poor conditions where its thin skeletal elements required less calcium carbonate and its unsupported branches were not subject to vigorous water movement. Heliophyllum stewarti n. sp. is based on a single specimen from the Tenmile Creek Dolomite (middle Givetian) in northwestern Ohio. The colony is phaceloid but each branch is an astreoid cluster without walls between individual corallites. In addition, the apparent protocorallite is turbinate with a larger diameter than any of the ceratoid offsets although offset lengths are several times that of the protocorallite. C1 SUNY BINGHAMTON,BINGHAMTON,NY 13902. RP OLIVER, WA (reprint author), US GEOL SURVEY,NATL MUSEUM NAT HIST,WASHINGTON,DC 20560, USA. NR 42 TC 2 Z9 3 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 NOV PY 1994 VL 68 IS 6 BP 1183 EP 1201 PG 19 WC Paleontology SC Paleontology GA PY141 UT WOS:A1994PY14100002 ER PT J AU POPOV, LY BLODGETT, RB ANDERSON, AV AF POPOV, LY BLODGETT, RB ANDERSON, AV TI FIRST OCCURRENCE OF THE GENUS BICARINATINA (BRACHIOPODA, INARTICULATA) FROM THE MIDDLE DEVONIAN IN NORTH-AMERICA (ALASKA) SO JOURNAL OF PALEONTOLOGY LA English DT Article AB The lingulid brachiopod species Bicarinatina kongakutensis n. sp. is recorded here from the Middle Devonian (Eifelian) Ulungarat unit in Arctic Alaska. A restudy of the type species, Bicarinatina bicarinata (Kutorga) from the Middle Devonian (Eifelian) of Eastern Europe, suggests close affinities to the Ordovician genus Pseudolingula and gives good reason to assign Bicarinatina to the family Pseudolingulidae. There are no important points of difference in the morphologies of Bicarinatina and the Early Carboniferous lingulid genus Liralingua and, thus, both genera have been synonymized. C1 US GEOL SURVEY,NATL CTR 970,RESTON,VA 22092. UNIV ALASKA,DEPT GEOL & GEOPHYS,FAIRBANKS,AK 99775. RP POPOV, LY (reprint author), ALL UNION GEOL RES INST,SREDNII PROSPEKT 74,ST PETERSBURG 199026,RUSSIA. OI Popov, Leonid/0000-0003-1710-2612 NR 13 TC 8 Z9 8 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 NOV PY 1994 VL 68 IS 6 BP 1214 EP 1218 PG 5 WC Paleontology SC Paleontology GA PY141 UT WOS:A1994PY14100004 ER PT J AU BAXTER, ME BLODGETT, RB AF BAXTER, ME BLODGETT, RB TI A NEW SPECIES OF DROHARHYNCHIA (BRACHIOPODA) FROM THE LOWER MIDDLE DEVONIAN (EIFELIAN) OF WEST-CENTRAL ALASKA SO JOURNAL OF PALEONTOLOGY LA English DT Article AB A new species of the genus Droharhynchia Sartenaer is established from lower Eifelian strata of west-central Alaska and the northwestern Brooks Range of Alaska. Droharhynchia rzhonsnitskayae n. sp. occurs in the Cheeneetnuk Limestone of the McGrath A-5 quadrangle, west-central Alaska, and the Baird Group of the Howard Pass B-5 quadrangle, northwestern Alaska. These occurrences extend the lower biostratigraphic range of both the genus and the subfamily Hadrorhynchiinae into the Eifelian. They also suggest close geographic proximity of the Farewell terrane of southwestern and west-central Alaska and the Arctic Alaska superterrane of northern Alaska during Devonian time. C1 US GEOL SURVEY,NATL CTR 970,RESTON,VA 22092. RP BAXTER, ME (reprint author), UNIV OREGON,DEPT GEOL SCI,EUGENE,OR 97403, USA. NR 24 TC 2 Z9 2 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 NOV PY 1994 VL 68 IS 6 BP 1235 EP 1240 PG 6 WC Paleontology SC Paleontology GA PY141 UT WOS:A1994PY14100006 ER PT J AU BLODGETT, RB JOHNSON, JG AF BLODGETT, RB JOHNSON, JG TI FIRST RECOGNITION OF THE GENUS VERNEUILIA HALL AND CLARKE (BRACHIOPODA, SPIRIFERIDA) FROM NORTH-AMERICA (WEST-CENTRAL ALASKA) SO JOURNAL OF PALEONTOLOGY LA English DT Article ID GENERA AB The brachiopod genus Vernacilia Hall and Clarke, 1893, is recognized for the first time in North America, where it is represented by a new species described here, V. langenstrasseni. This occurrence not only extends the geographic range of the genus, but also the lower age and stratigraphic limit into the Eifelian (early Middle Devonian). Previously, the oldest known species was the type, V. cheiropteryx d'Archiac and de Verneuil, 1842, from the Givetian Gate Middle Devonian) of Germany. Internal structures of V. langenstrasseni n. sp. are similar to those of genera in the ambocoeliid subfamily Rhynchospiriferinae, providing the first good evidence of a systematic relationship. C1 OREGON STATE UNIV,DEPT GEOSCI,CORVALLIS,OR 97331. RP BLODGETT, RB (reprint author), US GEOL SURVEY,NATL CTR 970,RESTON,VA 22092, USA. NR 19 TC 3 Z9 3 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 NOV PY 1994 VL 68 IS 6 BP 1240 EP 1242 PG 3 WC Paleontology SC Paleontology GA PY141 UT WOS:A1994PY14100007 ER PT J AU KENNEDY, WJ COBBAN, WA AF KENNEDY, WJ COBBAN, WA TI UPPER CAMPANIAN AMMONITES FROM THE MOUNT LAUREL SAND AT BIGGS FARM, DELAWARE SO JOURNAL OF PALEONTOLOGY LA English DT Review ID MAASTRICHTIAN BOUNDARY AB The Mount Laurel Sand at Biggs Farm, Delaware, yielded a diverse ammonite fauna comprising Pachydiscus (Pachydiscus) sp., Placenticeras cf. P. placenta (DeKay, 1828), Placenticeras n. sp., Eulophoceras sp., Nostaceras (Nastoceras) draconis Stephenson, 1941, Didymoceras cheyennense (Meek and Hayden, 1856a), Anaklinoceras reflexum Stephenson, 1941, Anaklinoceras tenuicostatum n. sp., Oxybeloceras meekanum (Whitfield, 1877), Solenoceras annulifer Morton, 1841, Baculites ovatus Say, 1820, B. undatus Stephenson, 1941, Hoploscaphites vistulensis Blaszkiewicz, 1980, and Jeletzkytes compressus (Roemer, 1841). The last named two species occur in Europe and indicate an upper but not uppermost upper Campanian horizon. Several species also occur in the Western Interior and suggest correlation with the Didymoceras cheyennense zone and part of the Baculites compressus zone of the upper Campanian in that region. C1 US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RP KENNEDY, WJ (reprint author), UNIV OFXORD MUSEUM, GEOL COLLECT, PK RD, OXFORD OX1 3PW, ENGLAND. NR 109 TC 10 Z9 11 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD NOV PY 1994 VL 68 IS 6 BP 1285 EP 1305 PG 21 WC Paleontology SC Paleontology GA PY141 UT WOS:A1994PY14100012 ER PT J AU PEOPLES, AD LOCHMILLER, RL LESLIE, DM ENGLE, DM AF PEOPLES, AD LOCHMILLER, RL LESLIE, DM ENGLE, DM TI PRODUCTION AND NUTRITIONAL QUALITY OF WESTERN RAGWEED SEED IN RESPONSE TO FERTILIZATION SO JOURNAL OF RANGE MANAGEMENT LA English DT Article DE AMBROSIA-PSILOSTACHYA; AMINO ACID; COLINUS-VIRGINIANUS; FERTILIZATION; NORTHERN BOBWHITE; OKLAHOMA; WESTERN RAGWEED ID AMINO-ACID-COMPOSITION; NITROGEN; WHEAT AB The importance of western ragweed (Ambrosia psilostachya) DC.) in the diet of bobwhites (Colinus virginianus Merr.) and their high dietary requirement for essential amino acids prompted us to explore the use of disking and fertilization (nitrogen and phosphorus) to improve its nutritional quality on deep, unfertile, sandy-soil rangelands in western Oklahoma. Fertilization (55 kg N ha-1, 56 kg P ha-1 as diammonium phosphate) of disk strips did not readily increase seed production of western ragweed. Fertilizer had no detectable effect on nutritional quality of seeds, which contained an average of 13% crude protein and 21% fat. Conflicting results reported on the effect of fertilizer on the quality of plant proteins within the literature could be attributable to differences of climate and soils, growth habits of different plant species, type and rates of fertilizers, and stages of maturity when plants are harvested for analysis. C1 OKLAHOMA STATE UNIV,DEPT ZOOL,STILLWATER,OK 74078. OKLAHOMA STATE UNIV,DEPT AGRON,STILLWATER,OK 74078. OKLAHOMA STATE UNIV,DEPT ZOOL,US FISH & WILDLIFE SERV,OKLAHOMA COOPERAT FISH & WILDLIFE RES UNIT,STILLWATER,OK 74078. OKLAHOMA DEPT WILDLIFE CONSERVAT,OKLAHOMA CITY,OK 73105. NR 26 TC 0 Z9 0 U1 0 U2 0 PU SOC RANGE MANAGEMENT PI DENVER PA 1839 YORK ST, DENVER, CO 80206 SN 0022-409X J9 J RANGE MANAGE JI J. Range Manage. PD NOV PY 1994 VL 47 IS 6 BP 467 EP 469 DI 10.2307/4002998 PG 3 WC Agriculture, Dairy & Animal Science; Ecology SC Agriculture; Environmental Sciences & Ecology GA PR302 UT WOS:A1994PR30200009 ER PT J AU BLUTH, GJS CASADEVALL, TJ SCHNETZLER, CC DOIRON, SD WALTER, LS KRUEGER, AJ BADRUDDIN, M AF BLUTH, GJS CASADEVALL, TJ SCHNETZLER, CC DOIRON, SD WALTER, LS KRUEGER, AJ BADRUDDIN, M TI EVALUATION OF SULFUR-DIOXIDE EMISSIONS FROM EXPLOSIVE VOLCANISM - THE 1982-1983 ERUPTIONS OF GALUNGGUNG, JAVA, INDONESIA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT-PINATUBO; CLOUDS; JUNE AB Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically through January 1983. During its most violent period from April to October, the Cikasasah Volcano Observatory reported 32 large and 56 moderate to small eruptions. From April 5 through September 19 the Total Ozone Mapping Spectrometer (TOMS), carried on NASA's Nimbus-7 satellite, detected and measured 24 different sulfur dioxide clouds; an estimated 1730 kilotons (kt) of SO2 were outgassed by these explosive eruptions. The trajectories, and rapid dispersion rates, of the SO2 clouds were consistent with injection altitudes below the tropopause. An additional 300 kt of SO2 were estimated to have come from 64 smaller explosive eruptions, based on the detection limit of the TOMS instrument. For the first time, an extended period of volcanic activity was monitored by remote sensing techniques which enabled observations of both the entire SO2 clouds produced by large explosive eruptions (using TOMS), and the relatively lower levels of SO2 emissions during non-explosive outgassing (using the Correlation Spectrometer, or COSPEC). Based on COSPEC measurements from August 1982 to January 1983, and on the relationship between explosive and non-explosive degassing, approximately 400 kt of SO2 were emitted during non-explosive activity. The total sulfur dioxide outgassed from Galunggung volcano from April 1982 to January 1983 is calculated to be 2500 kt (+/- 30%) from both explosive and non-explosive activity. While Galunggung added large quantities of sulfur dioxide to the atmosphere, its sporadic emissions occurred in relatively small events distributed over several months, and reached relatively low altitudes, and are unlikely to have significantly affected aerosol loading of the stratosphere in 1982 by volcanic activity. C1 UNIV MARYLAND,DEPT GEOL,COLLEGE PK,MD 20742. US GEOL SURVEY,DENVER,CO 80225. UNIV MARYLAND,DEPT GEOG,COLLEGE PK,MD 20742. HUGHES STX CORP,LANHAM,MD. NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DIRECTORATE,GREENBELT,MD 20771. DIREKTORAT VULKANOLOGI,DEPT PERTAMBANGAN DAN ENERGI,BANDUNG,INDONESIA. NR 21 TC 33 Z9 33 U1 0 U2 9 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 NOV PY 1994 VL 63 IS 3-4 BP 243 EP 256 DI 10.1016/0377-0273(94)90077-9 PG 14 WC Geosciences, Multidisciplinary SC Geology GA PY144 UT WOS:A1994PY14400009 ER PT J AU DIMITRAKOPOULOS, R MCCAMMON, RB SHOJI, T AF DIMITRAKOPOULOS, R MCCAMMON, RB SHOJI, T TI SPECIAL ISSUE - EXPERT-SYSTEMS AND ARTIFICIAL-INTELLIGENCE IN THE APPLIED GEOSCIENCES - 29TH IGC MEETING, AUGUST-SEPTEMBER-1992, KYOTO, JAPAN - PREFACE SO MATHEMATICAL GEOLOGY LA English DT Editorial Material C1 USGS,RESTON,VA. UNIV TOKYO,TOKYO,JAPAN. RP DIMITRAKOPOULOS, R (reprint author), MCGILL UNIV,MONTREAL,PQ,CANADA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD NOV PY 1994 VL 26 IS 8 BP 877 EP 878 DI 10.1007/BF02083419 PG 2 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA PZ781 UT WOS:A1994PZ78100001 ER PT J AU MCCAMMON, RB AF MCCAMMON, RB TI PROSPECTOR-II - TOWARDS A KNOWLEDGE-BASE FOR MINERAL-DEPOSITS SO MATHEMATICAL GEOLOGY LA English DT Article; Proceedings Paper CT Session on Expert Systems and Artificial Intelligence in the Applied Geosciences, at the 29th International Geological Congress (IGC) CY AUG 24-SEP 03, 1992 CL KYOTO, JAPAN SP INT ASSOC MATH GEOL DE EXPERT SYSTEMS; KNOWLEDGE BASE; MINERAL RESOURCE ASSESSMENT AB What began in the mid-seventies as a research effort in designing an expert system to aid geologists in exploring far hidden mineral deposits has in the late eighties become a full-sized knowledge-based system to aid geologists in conducting regional mineral resource assessments. Prospector II, the successor to Prospector, is interactive-graphics oriented, flexible in its representation of mineral deposit models, and suited to regional mineral resource assessment. In Prospector II, the geologist enters the findings for an area, selects the deposit models or examples of mineral deposits for consideration, and the program compares the findings with the models or the examples selected, noting the similarities, differences, and missing information. The models or the examples selected are ranked according to scores that are based on the comparisons with the findings. Findings can be reassessed and the process repeated if necessary. The results provide the geologist with a rationale for identifying those mineral deposit types that the geology of an area permits. In future, Prospector II can assist in the creation of new models used in regional mineral resource assessment and in striving toward an ultimate classification of mineral deposits. RP MCCAMMON, RB (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 14 TC 7 Z9 7 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD NOV PY 1994 VL 26 IS 8 BP 917 EP 936 DI 10.1007/BF02083422 PG 20 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA PZ781 UT WOS:A1994PZ78100004 ER PT J AU EDWARDS, K DAVIS, PA AF EDWARDS, K DAVIS, PA TI THE USE OF INTENSITY-HUE-SATURATION TRANSFORMATION FOR PRODUCING COLOR SHADED RELIEF IMAGES SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID LANDSAT TM AB We present a novel technique for combining color information from one raster dataset with intensity information from another by using an intensity-hue-saturation (IHS) transformation. This technique, which we refer to as intensity adjustment, is related to IHS transformation methods (e.g., intensity substitution) that have recently been used to combine remotely sensed multispectral images with achromatic images of higher spatial resolution. Our intensity-adjustment method is not appropriate for merging multispectral and achromatic images whose intensity information is mostly redundant, but our technique is more effective than the intensity-substitution method in merging databases whose intensities are nonredundant, such as a color thematic map and a shaded-relief base image. RP EDWARDS, K (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 7 TC 22 Z9 25 U1 0 U2 2 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 NOV PY 1994 VL 60 IS 11 BP 1369 EP 1374 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA PR263 UT WOS:A1994PR26300008 ER PT J AU SIPKIN, SA NEEDHAM, RE AF SIPKIN, SA NEEDHAM, RE TI MOMENT-TENSOR SOLUTIONS ESTIMATED USING OPTIMAL FILTER THEORY - GLOBAL SEISMICITY, 1993 SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Letter ID EARTHQUAKE SOURCE PARAMETERS; WAVEFORM DATA; INVERSION AB Moment-tensor solutions, estimated using optimal filter theory, are listed for 130 moderate-to-large size earthquakes occurring during 1993. RP SIPKIN, SA (reprint author), US GEOL SURVEY,MS 967,BOX 25046,DFC,DENVER,CO 80225, USA. NR 10 TC 9 Z9 9 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 NOV PY 1994 VL 86 IS 4 BP 245 EP 252 DI 10.1016/0031-9201(94)90123-6 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PT657 UT WOS:A1994PT65700001 ER PT J AU RIGGS, AC CARR, WJ KOLESAR, PT HOFFMAN, RJ AF RIGGS, AC CARR, WJ KOLESAR, PT HOFFMAN, RJ TI TECTONIC SPELEOGENESIS OF DEVILS-HOLE, NEVADA, AND IMPLICATIONS FOR HYDROGEOLOGY AND THE DEVELOPMENT OF LONG, CONTINUOUS PALEOENVIRONMENTAL RECORDS SO QUATERNARY RESEARCH LA English DT Article ID GREAT-BASIN; VEIN CALCITE; STRESS; AQUIFER; STATE AB Devils Hole, in southern Nevada, is a surface collapse into a deep, planar, steeply dipping fault-controlled fissure in Cambrian limestone and dolostone. The collapse intersects the water table about 15 m below land surface and the fissure extends at least 130 m deeper. Below water, most of the fissure is lined with a > 30-cm-thick layer of dense mammillary calcite that precipitated continuously from groundwater for > 500,000 yr. The thick mammillary calcite coat implies a long history of calcite-supersaturated groundwaters, which, combined with the absence of dissolutional morphologies, suggests that Devils Hole was not formed by karst processes. Devils Hole is located in a region of active extension; its tectonic origin is shown by evidence of spreading of its planar opening along a fault and by the orientation of its opening and others nearby, perpendicular to the northwest-southeast minimum principal stress direction of the region. Most Quaternary tectonic activity in the area, including seismicity and Quaternary faults and fractures, occurs on or parallel to northeast-striking structures. The hydrogeologic implications of this primarily structural origin are that fracture networks and caves opened by extensional tectonism can act as groundwater flowpaths functionally similar to those developed by karst processes and that, during active extension, transmissivity can be maintained despite infilling by mineral precipitation. Such extensional environments can provide conditions favorable for accumulation of deposits preserving long, continuous paleoenviromnental records. The precipitates in Devils Hole store chronologies of flow system water-level fluctuations, hydrochemistry, a half-million-yr proxy paleoclimate record, evidence of Devils Hole's tectonic origin, and probably atmospheric circulation. (C) 1994 University of Washington. C1 UTAH STATE UNIV,DEPT GEOL,LOGAN,UT 84322. US GEOL SURVEY,CARSON CITY,NV 89706. RP RIGGS, AC (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 421,DENVER,CO 80225, USA. NR 29 TC 19 Z9 19 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD NOV PY 1994 VL 42 IS 3 BP 241 EP 254 DI 10.1006/qres.1994.1075 PG 14 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PW722 UT WOS:A1994PW72200002 ER PT J AU CLARK, DH GILLESPIE, AR CLARK, MM AF CLARK, DH GILLESPIE, AR CLARK, MM TI DEBRIS-COVERED GLACIERS IN THE SIERRA-NEVADA, CALIFORNIA, AND THEIR IMPLICATIONS FOR SNOWLINE RECONSTRUCTION - REPLY SO QUATERNARY RESEARCH LA English DT Letter ID ROCK-GLACIERS; ORIGIN; RANGE C1 US GEOL SURVEY,MENLO PK,CA 94025. RP CLARK, DH (reprint author), UNIV WASHINGTON,DEPT GEOL SCI,AJ-20,SEATTLE,WA 98195, USA. NR 28 TC 9 Z9 9 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD NOV PY 1994 VL 42 IS 3 BP 359 EP 362 DI 10.1006/qres.1994.1088 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PW722 UT WOS:A1994PW72200015 ER PT J AU CAMPBELL, GS JUNGBAUER, JD BIDLAKE, WR HUNGERFORD, RD AF CAMPBELL, GS JUNGBAUER, JD BIDLAKE, WR HUNGERFORD, RD TI PREDICTING THE EFFECT OF TEMPERATURE ON SOIL THERMAL-CONDUCTIVITY SO SOIL SCIENCE LA English DT Article AB Simulation of soil temperatures under forest and range fires requires reliable estimates of soil thermal properties over a range of temperatures from ambient to about 600-degrees-C. We measured thermal conductivity of soil samples differing in texture, bulk density, water content, and temperature and then fit the results with a modification of the de Vries equation. Thermal conductivity increases dramatically with temperature in moist soil, reaching values 3 to 5 times the ambient value at 90-degrees-C. The modified de Vries theory agreed well with data at low temperature, and provided an upper boundary for measurements at higher temperatures. Only four parameters are required to specify thermal conductivity as a function of bulk density, temperature, and water content: thermal conductivity of the mineral fraction, water content at which liquid flow becomes limiting, a power for the liquid flow function, and a shape factor. Adequate estimates of the conductivity of the mineral fraction can be obtained from handbooks if the soil mineralogy is known, and the water content for liquid return flow can be predicted from soil texture. The other two parameters show a fairly narrow range of variation and can probably be estimated with sufficient accuracy for most simulation purposes. C1 USDI,USGS,TACOMA,WA 98402. USFS INTERMT FIRE SCI LAB,MISSOULA,MT 59807. RP CAMPBELL, GS (reprint author), WASHINGTON STATE UNIV,DEPT CROP & SOIL SCI,PULLMAN,WA 99164, USA. NR 8 TC 128 Z9 140 U1 3 U2 39 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0038-075X J9 SOIL SCI JI Soil Sci. PD NOV PY 1994 VL 158 IS 5 BP 307 EP 313 DI 10.1097/00010694-199411000-00001 PG 7 WC Soil Science SC Agriculture GA PW018 UT WOS:A1994PW01800001 ER PT J AU DORAZIO, RM HATTALA, KA MCCOLLOUGH, CB SKJEVELAND, JE AF DORAZIO, RM HATTALA, KA MCCOLLOUGH, CB SKJEVELAND, JE TI TAG RECOVERY ESTIMATES OF MIGRATION OF STRIPED BASS FROM SPAWNING AREAS OF THE CHESAPEAKE BAY SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID MOVEMENT; STOCK; FISH; TUNA; DYNAMICS; PACIFIC; MODEL; RATES AB In 1988-1991 striped bass Morone saxatilis were collected for tagging from various spawning areas within the Hudson River (New York) and the Chesapeake Bay (Maryland). The fish were tagged and released during traditional periods of spawing and recovered by commercial and recreational fishermen. The proportion of fish that migrated in spring-fall from spawning areas in Chesapeake Bay to more northern waters of mid-Atlantic and New England states was estimated from the geographically stratified tag returns. Most of the tagged fish were 40-100 cm total length (TL). The estimated proportion of migrant striped bass increased with body size, and nearly all fish larger than 100 cm TL left the bay during the spring-fall migration. Sex-specific differences in migration appear to be associated with the differences in body size of mature males and females, thus lending support to previously hypothesized patterns of striped bass migration. C1 NATL BIOL SURVEY,AQUAT ECOL BRANCH,KEARNEYSVILLE,WV 25430. NEW YORK STATE DEPT ENVIRONM CONSERVAT,NEW PALTZ,NY 12561. MARYLAND DEPT NAT RESOURCES,ANNAPOLIS,MD 21401. US FISH & WILDLIFE SERV,ANNAPOLIS,MD 21401. NR 47 TC 41 Z9 42 U1 0 U2 2 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 NOV PY 1994 VL 123 IS 6 BP 950 EP 963 DI 10.1577/1548-8659(1994)123<0950:TREOMO>2.3.CO;2 PG 14 WC Fisheries SC Fisheries GA PT715 UT WOS:A1994PT71500010 ER PT J AU NAFTZ, DL SPANGLER, LE AF NAFTZ, DL SPANGLER, LE TI SALINITY INCREASES IN THE NAVAJO AQUIFER IN SOUTHEASTERN UTAH SO WATER RESOURCES BULLETIN LA English DT Article DE GEOCHEMISTRY; GROUND WATER; WATER QUALITY; SALINITY; GREATER ANETH OIL FIELD, UTAH ID BRINE; WATER AB Salinity increases in water in some parts of the Navajo aquifer in southeastern Utah have been documented previously. The purpose of this paper is to use bromide, iodide, and chloride concentrations and del oxygen-18 and deuterium values in water from the study area to determine if oil-field brines (OFB) could be the source of increased salinity. Mixing-model results indicate that the bromide-to-chloride X 10,000 weight ratio characteristic of OFB in and outside the study area could not be causing the bromide depletion with increasing salinity in the Navajo aquifer. Mixing-model results indicate that a mixture of one percent OFB with 99 percent Navajo aquifer water would more than double the bromide-to-chloride weight ratio, instead of the observed decrease in the weight ratio with increasing chloride concentration. The trend of the mixing line representing the isotopically enriched samples from the Navajo aquifer does not indicate OFB as the source of isotopically enriched water; however, the simulated isotopic composition of injection water could be a salinity source. The lighter isotopic composition of OFB samples from the Aneth, Ratherford, White Mesa Unit, and McElmo Creek injection sites relative to the Ismay site is a result of continued recycling of injection water mixed with various proportions of isotopically lighter make-up water from the alluvial aquifer along the San Juan River. A mixing model using the isotopic composition of the simulated injection water suggests that enriched samples from the Navajo aquifer are composed of 36 to 75 percent of the simulated injection water. However, chloride concentrations predicted by the isotopic mixing model are up to 13.4 times larger than the measured chloride concentrations in isotopically enriched samples from the Navajo aquifer, indicating that injection water is not the source of increased salinity. Geochemical data consistently show that OFB and associated injection water from the Greater Aneth Oil Field are not the source of salinity increases in the Navajo aquifer. RP NAFTZ, DL (reprint author), US GEOL SURVEY,1745 W 1700 S,SALT LAKE CITY,UT 84104, USA. NR 35 TC 5 Z9 5 U1 0 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 NOV-DEC PY 1994 VL 30 IS 6 BP 1119 EP 1135 PG 17 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA QB051 UT WOS:A1994QB05100015 ER PT J AU WOLOCK, DM PRICE, CV AF WOLOCK, DM PRICE, CV TI EFFECTS OF DIGITAL ELEVATION MODEL MAP SCALE AND DATA RESOLUTION ON A TOPOGRAPHY-BASED WATERSHED MODEL SO WATER RESOURCES RESEARCH LA English DT Article ID CATCHMENT GEOMORPHOLOGY; HYDROLOGIC SIMILARITY; RUNOFF PRODUCTION; SOIL; FLOW; SENSITIVITY; AREAS AB The effects of digital elevation model (DEM) map scale and data resolution on watershed model predictions of hydrologic characteristics were determined for TOPMODEL, a topography-based watershed model. The effects of topography on watershed hydrology are represented in TOPMODEL as the distribution of ln (a/tan B), where ln is the Napierian logarithm, a is the upslope area per unit contour length, and tan B is the gravitational gradient. The minimum, maximum, mean, variance, and skew values of the ln (a/tan B) distribution were computed from 1:24,000-scale (24K) DEMs at 30- and 90-m resolutions and from 1:250,000-scale (250K) DEMs at 90-m resolution for 71 areas in Pennsylvania, New York, and New Jersey. An analysis of TOPMODEL showed that model predictions of the depth to the water table, the ratio of overland flow to total flow, peak flow, and variance and skew of predicted streamflow were affected by both the DEM map scale and data resolution. Further TOPMODEL analyses showed that the effects of DEM map scale and data resolution on model predictions were due to the sensitivity of the predictions to the mean of the ln (a/tan B) distribution, which was affected by both DEM map scale and data resolution. DEM map scale affected the mean of the ln (a/tan B) distribution through its influence on the mean of the ln (a) distribution, which characterizes land-surface shape, and the mean of ln (1/tan B) distribution, which characterizes land-surface slope. DEM resolution, in contrast, affected the mean of the ln (a/tan B) distribution primarily by its influence on the mean of the ln (a) distribution. C1 US GEOL SURVEY,W TRENTON,NJ 08628. RP WOLOCK, DM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. NR 37 TC 208 Z9 225 U1 2 U2 29 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 1994 VL 30 IS 11 BP 3041 EP 3052 DI 10.1029/94WR01971 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA PP213 UT WOS:A1994PP21300017 ER PT J AU KARGEL, JS AF KARGEL, JS TI METALLIFEROUS ASTEROIDS AS POTENTIAL SOURCES OF PRECIOUS METALS SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID IRON-METEORITES; FRACTIONATION; SYSTEMATICS; CHONDRITES; VOLCANISM; RHENIUM; EARTH AB Recent discoveries of near-Earth asteroids (NEAs) and chemical analyses of fragments of asteroids (meteorites) suggest that there may be a gold mine, literally, in near-Earth space. Judged from meteorite analyses, two types of asteroids offer particularly bright prospects for recovery of large quantities of precious metals (defined as Au, Pt, Ir, Os, Pd, Rh, and Ru), the ordinary LL chondrites, which contain 1.2-5.3% Fe-Ni metal containing 50-220 ppm of precious metals, and metallic asteroids, which consist almost wholly of Fe-Ni phases and contain variable amounts of precious metals up to several hundred ppm. The pulverized regolith of LL chondrite asteroids could be electromagnetically raked to separate the metallic grains. Suitable metallic asteroids could be processed in their entirety. Statistically, there should be approximately six metallic NEAs larger than 1 km in diameter that contain over 100 ppm of precious metals. Successful recovery of 400,000 tons or more of precious metals contained in the smallest and least rich of these metallic NEAs could yield products worth $5.1 trillion (US) at recent market prices. If marketed over 20 years, this would represent a 10-fold increase over the recent global production rate of all precious metals combined. The market response to the hypothetical introduction of such large quantities of precious metals is difficult to predict, because these metals historically have not obeyed normal economic laws of the market. An empirical model suggests that the effects on market prices of a hypothetical increase in production of a given metal can be predicted given existing knowledge of the metal's present market value and production rate. This model suggests that the total value of 400,000 metric tons of precious metals, if marketed over 20 years, would decline to about 320 billion ($16 billion per year). Except for Au, for which production and prices would be marginally affected, the market prices of precious metals may decline by 1 to 2 orders of magnitude if one of the six asteroids were to be mined to depletion over 20 years. Less conservatively, there is a 50% chance that the richest metallic NEA contains at least 1.9 million metric tons of precious metals; this quantity, if marketed over 40 years, may be worth approximately $900 billion at collapsed market prices ($22.5 billion per year). The actual economic and technological impact of asteroidal metals may be considerably greater due to the increased availability and reduced prices of these resources. Despite this great potential, first-order technological, scientific, and economic uncertainties remain before the feasibility of exploitation of asteroids for precious metals can be ascertained. RP KARGEL, JS (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 46 TC 12 Z9 13 U1 3 U2 26 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 OCT 25 PY 1994 VL 99 IS E10 BP 21129 EP 21141 DI 10.1029/94JE02141 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PN669 UT WOS:A1994PN66900002 ER PT J AU BATSON, RM KIRK, RL EDWARDS, K MORGAN, HF AF BATSON, RM KIRK, RL EDWARDS, K MORGAN, HF TI VENUS CARTOGRAPHY SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MAGELLAN AB The entire surface of the planet Venus is being mapped at global and regional scales (1:50,000,000 through 1:1,500,000) with synthetic aperture radar (SAR), radar altimeter, and radiometer measurements of physical properties from the Magellan spacecraft. The mapping includes SAR image mosaics, shaded relief maps, and topographic contour overlays made from altimetry data and by radargrammetric methods. Methods used include new techniques of radar image processing that became operational as a result of the Magellan mission. The area being mapped (at a resolution of 75 m/pixel) is roughly equivalent to that of Earth, including seafloors. The mapping is designed to support geologic and geophysical investigations. RP BATSON, RM (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 17 TC 3 Z9 3 U1 0 U2 0 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 OCT 25 PY 1994 VL 99 IS E10 BP 21173 EP 21181 DI 10.1029/94JE01908 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PN669 UT WOS:A1994PN66900005 ER PT J AU BOWN, TM HOLROYD, PA ROSE, KD AF BOWN, TM HOLROYD, PA ROSE, KD TI MAMMAL EXTINCTIONS, BODY-SIZE, AND PALEOTEMPERATURE SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ALLUVIAL PALEOSOLS; WILLWOOD FORMATION; FLOODPLAIN SUITES; LOWER EOCENE; PRIMATES; INTEGRATION; CHANNEL; EVENTS AB There is a general inverse relationship between the natural logarithm of tooth area (a body size indicator) of some fossil mammals and paleotemperature during approximately 2.9 million years of the early Eocene in the Bighorn Basin of northwest Wyoming, When mean temperatures became warmer, tooth areas tended to become smaller. During colder times, larger species predominated; these generally became larger or remained the same size. Paleotemperature trends also markedly affected patterns of local (and, perhaps, regional) extinction and immigration. New species appeared as immigrants during or near the hottest (smaller forms) and coldest (larger forms) intervals. Paleotemperature trend reversals commonly resulted in the ultimate extinction of both small forms (during cooling intervals) and larger forms (during warming intervals). These immigrations and extinctions mark faunal turnovers that were also modulated by sharp increases in sediment accumulation rate. C1 JOHNS HOPKINS UNIV, SCH MED, DEPT CELL BIOL & ANAT, BALTIMORE, MD 21205 USA. RP US GEOL SURVEY, DENVER FED CTR, MS 919, BOX 25046, DENVER, CO 80225 USA. NR 27 TC 17 Z9 19 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 25 PY 1994 VL 91 IS 22 BP 10403 EP 10406 DI 10.1073/pnas.91.22.10403 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PP698 UT WOS:A1994PP69800034 PM 7937963 ER PT J AU JONES, L AKI, K BOORE, D CELEBI, M DONNELLAN, A HALL, J HARRIS, R HAUKSSON, E HEATON, T HOUGH, S HUDNUT, K HUTTON, K JOHNSTON, M JOYNER, W KANAMORI, H MARSHALL, G MICHAEL, A MORI, J MURRAY, M PONTI, D REASENBERG, P SCHWARTZ, D SEEBER, L SHAKAL, A SIMPSON, R THIO, H TINSLEY, J TODOROVSKA, M TRIFUNAC, M WALD, D ZOBACK, ML AF JONES, L AKI, K BOORE, D CELEBI, M DONNELLAN, A HALL, J HARRIS, R HAUKSSON, E HEATON, T HOUGH, S HUDNUT, K HUTTON, K JOHNSTON, M JOYNER, W KANAMORI, H MARSHALL, G MICHAEL, A MORI, J MURRAY, M PONTI, D REASENBERG, P SCHWARTZ, D SEEBER, L SHAKAL, A SIMPSON, R THIO, H TINSLEY, J TODOROVSKA, M TRIFUNAC, M WALD, D ZOBACK, ML TI THE MAGNITUDE-6.7 NORTHRIDGE, CALIFORNIA, EARTHQUAKE OF 17-JANUARY-1994 SO SCIENCE LA English DT Article ID STRONG GROUND MOTION; 1971 SAN-FERNANDO; WHITTIER-NARROWS EARTHQUAKE; BOORE ATTENUATION DATA; SOUTHERN-CALIFORNIA; VENTURA BASIN; ANDREAS FAULT; LOS-ANGELES; SEISMICITY; VALLEY AB The most costly American earthquake since 1906 struck Los Angeles on 17 January 1994. The magnitude 6.7 Northridge earthquake resulted from more than 3 meters of reverse slip on a 15-kilometer-long south-dipping thrust fault that raised the Santa Susana mountains by as much as 70 centimeters. The fault appears to be truncated by the fault that broke in the 1971 San Fernando earthquake at a depth of 8 kilometers. Of these two events, the Northridge earthquake caused many times more damage, primarily because its causative fault is directly under the city. Many types of structures were damaged, but the fracture of welds in steel-frame buildings was the greatest surprise. The Northridge earthquake emphasizes the hazard posed to Los Angeles by concealed thrust faults and the potential for strong ground shaking in moderate earthquakes. C1 UNIV SO CALIF, DEPT GEOL, LOS ANGELES, CA 90089 USA. CALTECH, JET PROP LAB, PASADENA, CA 91125 USA. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92103 USA. CALIF DIV MINES & GEOL, PLEASANT HILL, CA USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. RP US GEOL SURVEY, 525 S WILSON AVE, PASADENA, CA 91106 USA. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010; Michael, Andrew/A-5059-2010; Harris, Ruth/C-4184-2013; OI Hudnut, Kenneth/0000-0002-3168-4797; Michael, Andrew/0000-0002-2403-5019; Harris, Ruth/0000-0002-9247-0768; Hauksson, Egill/0000-0002-6834-5051; Wald, David/0000-0002-1454-4514 NR 54 TC 81 Z9 82 U1 2 U2 11 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 OCT 21 PY 1994 VL 266 IS 5184 BP 389 EP 397 PG 9 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PN272 UT WOS:A1994PN27200023 ER PT J AU REIMER, GM AF REIMER, GM TI RADON AND LUNG-CANCER SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Letter RP REIMER, GM (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU MASS MEDICAL SOC PI BOSTON PA 10 SHATTUCK, BOSTON, MA 02115 SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD OCT 20 PY 1994 VL 331 IS 16 BP 1098 EP 1098 DI 10.1056/NEJM199410203311618 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA PL560 UT WOS:A1994PL56000026 PM 8090179 ER PT J AU BEAUDOIN, BC MAGEE, M BENZ, H AF BEAUDOIN, BC MAGEE, M BENZ, H TI CRUSTAL VELOCITY STRUCTURE NORTH OF THE MENDOCINO TRIPLE JUNCTION SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CASCADIA SUBDUCTION ZONE; GORDA PLATE; CALIFORNIA; TECTONICS AB A 140-km-long refraction/wide-angle reflection profile recently recorded by Stanford University and the U. S. Geological Survey imaged the subducting Gorda slab beneath northern California. The profile, which is subparallel to the coast from Cape Mendocino northward, indicates that the North American plate is 13- to 14-km-thick along the coast north of Cape Mendocino. The crust is characterized by relatively uniform, low velocities of less-than-or-equal-to6 km/s interpreted as Franciscan rocks. Two strong reflections define the upper and lower boundaries of the subducting Gorda crust. Our data indicate that the subducting Gorda crust thickens northward from Cape Mendocino from 7-km-thick just north of Cape Mendocino to 10-km-thick 120 km to the north. This change in thickness is coincident with a change in velocity from 6.7 km/s south to 6.2 km/s north. Mantle velocities of 7.7 km/s are observed for offsets greater than c. 80 km. We interpret our model to indicate that the Gorda slab is not imbricated on a crustal scale beneath our profile, that sediments and/or a tectonically thickened oceanic layer 2 are present to the north but not in the vicinity of Cape Mendocino, and that proximity to the Mendocino triple junction affects the way sediments are subducted. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,GOLDEN,CO 80401. RP BEAUDOIN, BC (reprint author), STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 23 TC 11 Z9 11 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 OCT 15 PY 1994 VL 21 IS 21 BP 2319 EP 2322 DI 10.1029/94GL02154 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PN308 UT WOS:A1994PN30800015 ER PT J AU MCKAY, CP CLOW, GD ANDERSEN, DT WHARTON, RA AF MCKAY, CP CLOW, GD ANDERSEN, DT WHARTON, RA TI LIGHT TRANSMISSION AND REFLECTION IN PERENNIALLY ICE-COVERED LAKE HOARE, ANTARCTICA SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA ICE; RADIATIVE-TRANSFER; HEATING RATES; ABSORPTION; LIGHT; SEDIMENTATION; ATMOSPHERES; COMMUNITIES; SCATTERING; IRRADIANCE AB We have investigated the transmission and albedo of the perennial ice cover on Lake Hoare, Antarctica. Our database consists of year-round measurements of the photosynthetically active radiation (400-700 nm) under the ice, measurements of the spatial variation of the under-ice light in midsummer, and spectrally resolved measurements from 400 to 700 nm of the albedo and transmission of the ice cover in early (November) and in midsummer (January). Our results show that the transmission decreases in the first part of summer, dropping by a factor of approximately 4 from November to January. We suggest that this is due to heating in the upper layers of the ice cover and the formation of Tyndall figures. Later in the summer when a significant liquid water fraction occurs within the ice cover, the transmission increases. In the fall when the ice cover freezes solid the transmission drops markedly. The spectrally resolved measurements from 400 to 700 nm show that approximately 2-5% of the incident light in this spectral region penetrates the 3.5-m thick ice cover. We have analyzed the spectral data using a two-stream scattering solution to the radiative transfer equation with three vertical layers in the ice cover. A surficial glaze of scattering ice 1 cm thick overlies a layer of sandy, bubbly ice about a meter thick, and below this is a thick layer of sand-free ice with bubbles. We find that the ice cover is virtually opaque at wavelengths longer than 800 nm. The net transmission of solar energy is approximately 2%. Significant changes in the thickness of the ice cover have been reported at Lake Hoare. These are due primarily to changes in the thickness of the bottom layer only. Because this layer is relatively clear, the effect on the transmission through the ice cover from these changes is less than would be predicted assuming a homogeneous ice cover. C1 DESERT RES INST,CTR BIOL SCI,RENO,NV 89506. US GEOL SURVEY,ASTROGEOL BRANCH,MENLO PK,CA 94025. RP MCKAY, CP (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. NR 31 TC 37 Z9 37 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1994 VL 99 IS C10 BP 20427 EP 20444 DI 10.1029/94JC01414 PG 18 WC Oceanography SC Oceanography GA PM276 UT WOS:A1994PM27600009 ER PT J AU TREHU, AM ASUDEH, I BROCHER, TM LUETGERT, JH MOONEY, WD NABELEK, JL NAKAMURA, Y AF TREHU, AM ASUDEH, I BROCHER, TM LUETGERT, JH MOONEY, WD NABELEK, JL NAKAMURA, Y TI CRUSTAL ARCHITECTURE OF THE CASCADIA FORE-ARC SO SCIENCE LA English DT Article ID NORTHWESTERN UNITED-STATES; WESTERN OREGON; BENEATH WASHINGTON; TECTONIC EVOLUTION; SEISMIC REFRACTION; CONVERGENT MARGIN; CHUGACH MOUNTAINS; STRUCTURAL TRENDS; NORTHERN OREGON; SOUTHERN ALASKA AB Seismic profiling data indicate that the thickness of an accreted oceanic terrane of Paleocene and early Eocene age, which forms the basement of much of the forearc beneath western Oregon and Washington, varies by approximately a factor of 4 along the strike of the Cascadia subduction zone. Beneath the Oregon Coast Range, the accreted terrane is 25 to 35 kilometers thick, whereas offshore Vancouver Island it is about 6 kilometers thick. These variations are correlated with variations in are magmatism, forearc seismicity, and long-term forearc deformation. It is suggested that the strength of the forearc crust increases as the thickness of the accreted terrane increases and that the geometry of the seaward edge of this terrane influences deformation within the subduction complex and controls the amount of sediment that is deeply subducted. C1 GEOL SURVEY CANADA,OTTAWA K1A 0Y3,ON,CANADA. US GEOL SURVEY,MENLO PK,CA 94025. UNIV TEXAS,INST GEOPHYS,AUSTIN,TX 78759. RP TREHU, AM (reprint author), OREGON STATE UNIV,DEPT OCEAN & ATMOSPHER SCI,OCEANOG ADM BLDG 104,CORVALLIS,OR 97331, USA. RI Nakamura, Yosio/A-2120-2009; OI Brocher, Thomas/0000-0002-9740-839X NR 56 TC 108 Z9 108 U1 1 U2 21 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 14 PY 1994 VL 266 IS 5183 BP 237 EP 243 DI 10.1126/science.266.5183.237 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PM134 UT WOS:A1994PM13400022 PM 17771442 ER PT J AU KISSLING, E ELLSWORTH, WL EBERHARTPHILLIPS, D KRADOLFER, U AF KISSLING, E ELLSWORTH, WL EBERHARTPHILLIPS, D KRADOLFER, U TI INITIAL REFERENCE MODELS IN LOCAL EARTHQUAKE TOMOGRAPHY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ANDREAS FAULT ZONE; VELOCITY STRUCTURE; SAN-ANDREAS; CRUSTAL STRUCTURE; CENTRAL CALIFORNIA; TIME TOMOGRAPHY; INVERSION; HETEROGENEITY; HYPOCENTERS; ANOMALIES AB The inverse problem of three-dimensional (3-D) local earthquake tomography is formulated as a linear approximation to a nonlinear function. Thus the solutions obtained and the reliability estimates depend on the initial reference model. Inappropriate models may result in artifacts of significant amplitude. Here, we advocate the application of the same inversion formalism to determine hypocenters and one-dimensional (1-D) velocity model parameters, including station corrections, as the first step in the 3-D modeling process. We call the resulting velocity model the minimum 1-D model. For test purposes, a synthetic data set based on the velocity structure of the San Andreas fault zone in central California was constructed. Two sets of 3-D tomographic P velocity results were calculated with identical travel time data and identical inversion parameters. One used an initial 1-D model selected from a priori knowledge of average crustal velocities, and the other used the minimum 1-D model. When the data well resolve the structure, the 3-D image obtained with the minimum 1-D model is much closer to the true model than the one obtained with the a priori reference model. In zones of poor resolution, there are fewer artifacts in the 3-D image based on the minimum 1-D model. Although major characteristics of the 3-D velocity structure are present in both images, proper interpretation of the results obtained with the a priori 1-D model is seriously compromised by artifacts that distort the image and that go undetected by either resolution or covariance diagnostics. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. INST GEOL & NUCL SCI, WELLINGTON, NEW ZEALAND. RP KISSLING, E (reprint author), ETH HOENGGERBERG, INST GEOPHYS, CH-8093 ZURICH, SWITZERLAND. NR 49 TC 450 Z9 477 U1 4 U2 21 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 1994 VL 99 IS B10 BP 19635 EP 19646 DI 10.1029/93JB03138 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL027 UT WOS:A1994PL02700002 ER PT J AU WANG, CY HWANG, WT COCHRANE, GR AF WANG, CY HWANG, WT COCHRANE, GR TI TECTONIC DEWATERING AND MECHANICS OF PROTOTHRUST ZONES - EXAMPLE FROM THE CASCADIA ACCRETIONARY MARGIN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BARBADOS RIDGE COMPLEX; SEISMIC-REFLECTION DATA; MIDDLE AMERICA TRENCH; THRUST BELTS; SEDIMENT ACCRETION; CONTACT PROBLEMS; FLUID PRESSURES; PORE PRESSURE; COSTA-RICA; FLOW AB Recent analyses of multichannel seismic data for the Cascadia margin off central Oregon show a systematic, landward increase in velocity (increase in sediment dewatering) within a protothrust zone about 10 km wide seaward of the toe of the accretionary wedge (Cochrane et al., 1994). Here we analyze the mechanical conditions for the transmission of compression from the rear of the accretionary wedge to the area seaward of the frontal thrust to create the protothrust zone and to cause sediment dewatering. The analysis assumes that sediments are elastoplastic (Coulomb) material; i.e., they behave elastically up to a yield limit at which failure occurs. We show that the necessary conditions for the transmission of compression from the accretionary wedge to the seaward area are (1) the presence of incipient decollements seaward of the frontal thrust and (2) the presence of high pore pressures within the incipient decollement. We also show that the magnitude of pore pressure within the incipient decollement may control the width of the protothrust zone. We suggest that the latter determines the location of the next frontal thrust and hence the ramp spacing between the imbricated thrusts within accretionary wedges. Thus pore pressures within incipient decollements may significantly influence the evolution of the internal structures of accretionary wedges. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP WANG, CY (reprint author), UNIV CALIF BERKELEY, DEPT GEOL & GEOPHYS, BERKELEY, CA 94720 USA. NR 55 TC 5 Z9 5 U1 1 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 1994 VL 99 IS B10 BP 20043 EP 20050 DI 10.1029/94JB01545 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL027 UT WOS:A1994PL02700028 ER PT J AU BURGMANN, R ARROWSMITH, R DUMITRU, T MCLAUGHLIN, R AF BURGMANN, R ARROWSMITH, R DUMITRU, T MCLAUGHLIN, R TI RISE AND FALL OF THE SOUTHERN SANTA-CRUZ MOUNTAINS, CALIFORNIA, FROM FISSION TRACKS, GEOMORPHOLOGY, AND GEODESY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LOMA-PRIETA EARTHQUAKE; ANDREAS FAULT ZONE; FRANCISCAN SUBDUCTION; PACIFIC-PLATE; UPLIFT; SLIP; DEFORMATION; HISTORY; MOTION; BASIN AB The Santa Cruz Mountains are closely associated with a left bend along the right-lateral San Andreas fault. The Loma Prieta area on the northeast side of the San Andreas consists of fault-bounded blocks that rise along active, deeply rooted, reverse and oblique-slip faults. Six samples from a transect across this area yield concordant apatite fission track ages averaging 4.6 +/- 0.5 Ma. These ages date the time of cooling below similar to 110 degrees C and suggest that about 3 km of unroofing has occurred over the last 4.6 m.y. Allowing for current elevations of about 1 km, this suggests an average uplift rate of the order of 0.8 mm/yr over the last 4.6 m.y. To further define the extent and distribution of this young uplift, we used morphometric analyses of the youthful topography of the area. Steep drainage slopes and high local relief indicate that the area northeast of the San Andreas forms a well-defined zone of high uplift. In contrast, the region on the southwest side of the San Andreas is characterized by broad upwarping and folding, more subdued topography, old fission track ages, and mean Quaternary uplift rates of 0.1-0.4 mm/yr. Geodetic data (1906 San Francisco earthquake and subsequent strain transients, 20 years of interseismic deformation, 1989 Loma Prieta earthquake, and 2 years of post-Loma Prieta earthquake strain) show that the Southern Santa Cruz Mountains repeatedly rise and subside through a complex sequence of bay area deformation events. An additional deformation element that involves reverse slip averaging 2-3 mm/yr along the Foothills thrust system must occur to explain the longer-term uplift pattern in the Loma Prieta area since the late Pliocene. The asymmetry in deformation on opposite sides of the San Andreas probably reflects the contrasting rock types on opposite sides of the fault, the influence of preexisting structures, and the interaction with neighboring faults of the San Andreas system. C1 STANFORD UNIV, DEPT GEOL & ENVIRONM SCI, STANFORD, CA 94305 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP BURGMANN, R (reprint author), STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. NR 83 TC 52 Z9 52 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 1994 VL 99 IS B10 BP 20181 EP 20202 DI 10.1029/94JB00131 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL027 UT WOS:A1994PL02700037 ER PT J AU GOMBERG, J ELLIS, M AF GOMBERG, J ELLIS, M TI TOPOGRAPHY AND TECTONICS OF THE CENTRAL NEW MADRID SEISMIC ZONE - RESULTS OF NUMERICAL EXPERIMENTS USING A 3-DIMENSIONAL BOUNDARY-ELEMENT PROGRAM SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; HALF-SPACE; DEFORMATION; CALIFORNIA; EARTHQUAKES; PARKFIELD; STRAIN; MODELS; STRESS; RATES AB We present results of a series of numerical experiments designed to test hypothetical mechanisms that drive deformation in the New Madrid seismic zone. Experiments are constrained by subtle topography and the distribution of seismicity in the region. We use a new boundary element algorithm that permits calculation of the three-dimensional deformation field. Surface displacement fields are calculated for the New Madrid zone under both far-field (plate tectonic scale) and locally derived driving strains. Results demonstrate that surface displacement fields cannot distinguish between either a far-field simple or pure shear strain field or one that involves a deep shear zone beneath the upper crustal faults. Thus, neither geomorphic nor geodetic studies alone are expected to reveal the ultimate driving mechanism behind the present-day deformation. We have also tested hypotheses about strain accommodation within the New Madrid contractional step-over by including linking faults, two southwest dipping and one vertical, recently inferred from microearthquake data. Only those models with step-over faults are able to predict the observed topography. Surface displacement fields for long-term, relaxed deformation predict the distribution of uplift and subsidence in the contractional step-over remarkably well. Generation of these displacement fields appear to require slip on both the two northeast trending vertical faults and the two dipping faults in the step-over region, with very minor displacements occurring during the interseismic period when the northeast trending vertical faults are locked. These models suggest that the gently dipping central step-over fault is a reverse fault and that the steeper fault, extending to the southeast of the step-over, acts as a normal fault over the long term. RP GOMBERG, J (reprint author), MEMPHIS STATE UNIV, CTR EARTHQUAKE RES & INFORMAT, US GEOL SURVEY, 3890 CENT AVE, MEMPHIS, TN 38152 USA. NR 40 TC 83 Z9 87 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 OCT 10 PY 1994 VL 99 IS B10 BP 20299 EP 20310 DI 10.1029/94JB00039 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL027 UT WOS:A1994PL02700043 ER PT J AU SZABO, BJ LUDWIG, KR MUHS, DR SIMMONS, KR AF SZABO, BJ LUDWIG, KR MUHS, DR SIMMONS, KR TI TH-230 AGES OF CORALS AND DURATION OF THE LAST INTERGLACIAL SEA-LEVEL HIGH STAND ON OAHU, HAWAII SO SCIENCE LA English DT Article ID OXYGEN ISOTOPE RECORD; MASS-SPECTROMETRY; ABROLHOS ISLANDS; DEVILS-HOLE; PERIOD; CLIMATE; TH-230; REEFS; CHRONOLOGY; AUSTRALIA AB Thorium-230 ages of emergent marine deposits on Oahu, Hawaii, have a uniform distribution of ages from similar to 114,000 to similar to 131,000 years, indicating a duration for the last interglacial sea-level high stand of similar to 17,000 years, in contrast to a duration of similar to 8000 years inferred from the orbitally tuned marine oxygen isotope record. Sea level on Oahu rose to greater than or equal to 1 to 2 meters higher than present by 131,000 years ago or similar to 6000 years earlier than inferred from the marine record. Although the latter record suggests a shift back to glacial conditions beginning at similar to 119,000 years ago, the Oahu coral ages indicate a near present sea level until similar to 114,000 years ago. RP SZABO, BJ (reprint author), US GEOL SURVEY,DENVER FED CTR,MAIL STOP 963,BOX 25046,DENVER,CO 80225, USA. NR 43 TC 96 Z9 99 U1 0 U2 10 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 7 PY 1994 VL 266 IS 5182 BP 93 EP 96 DI 10.1126/science.266.5182.93 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PK582 UT WOS:A1994PK58200029 PM 17814002 ER PT J AU OREMLAND, RS MILLER, LG CULBERTSON, CW CONNELL, TL JAHNKE, L AF OREMLAND, RS MILLER, LG CULBERTSON, CW CONNELL, TL JAHNKE, L TI DEGRADATION OF METHYL-BROMIDE BY METHANOTROPHIC BACTERIA IN CELL-SUSPENSIONS AND SOILS SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID METHANE MONO-OXYGENASE; OZONE DEPLETION; DIMETHYL ETHER; OXIDATION; METABOLISM; SEDIMENTS; ACETYLENE; SEAWATER; FLUORIDE; HALIDES AB Cell suspensions of Methylococcus capsulatus mineralized methyl bromide (MeBr), as evidenced by its removal from the gas phase, the quantitative recovery bf Br- in the spent medium, and the production of (CO2)-C-14, from [C-14]MeBr. Methyl fluoride (MeF) inhibited oxidation of methane as well as that of [C-14]MeBr. The rate of MeBr consumption by cells varied inversely with the supply of methane, which suggested a competitive relationship between these two substrates. However, MeBr did not support growth of the methanotroph. In soils exposed to high levels (10,000 ppm) of MeBr, methane oxidation,vas completely inhibited. At this concentration, MeBr removal rates were equivalent in killed and live controls, which indicated a chemical rather than biological removal reaction. At lower concentrations (1,000 ppm) of MeBr, methanotrophs were active and MeBr consumption rates were 10-fold higher in live controls than in killed controls. Soils exposed to trace levels (10 ppm) of MeBr demonstrated complete consumption within 5 h of incubation, while controls inhibited with MeF or incubated without O-2 had 50% lower removal rates. Aerobic soils oxidized [C-14]MeBr to (CO2)-C-14, and MeF inhibited oxidation by 72%. Field experiments demonstrated slightly lower MeBr removal rates in chambers containing MeF than in chambers lacking MeF. Collectively, these results show that soil methanotrophic bacteria, as well as other microbes, can degrade MeBr present in the environment. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP OREMLAND, RS (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 37 TC 54 Z9 55 U1 0 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 OCT PY 1994 VL 60 IS 10 BP 3640 EP 3646 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA PK266 UT WOS:A1994PK26600025 PM 7986039 ER PT J AU CACCAVO, F LONERGAN, DJ LOVLEY, DR DAVIS, M STOLZ, JF MCINERNEY, MJ AF CACCAVO, F LONERGAN, DJ LOVLEY, DR DAVIS, M STOLZ, JF MCINERNEY, MJ TI GEOBACTER SULFURREDUCENS SP-NOV, A HYDROGEN-OXIDIZING AND ACETATE-OXIDIZING DISSIMILATORY METAL-REDUCING MICROORGANISM SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID DESULFUROMONAS-ACETOXIDANS; PHYLOGENETIC ANALYSIS; ELEMENTAL SULFUR; RIBOSOMAL-RNA; REDUCTION; IRON; BACTERIA; OXIDATION; MANGANESE; URANIUM AB A dissimilatory metal- and sulfur-reducing microorganism was isolated from surface sediments of a hydrocarbon-contaminated ditch in Norman, Okla. The isolate, which was designated strain PCA, was an obligately anaerobic, nonfermentative, nonmotile, gram-negative rod. PCA grew in a defined medium with acetate as an electron donor and ferric PPi, ferric oxyhydroxide, ferric citrate, elemental sulfur, Co(III)-EDTA, fumarate, or malate as the sole electron acceptor. PCA also coupled the oxidation of hydrogen to the reduction of Fe(III) but did not reduce Fe(III) with sulfur, glucose, lactate, fumarate, propionate, butyrate, isobutryate, isovalerate, succinate, yeast extract, phenol, benzoate, ethanol, propanol, or butanol as an electron donor. PCA did not reduce oxygen, Mn(IV), U(VI), nitrate, sulfate, sulfite, or thiosulfate with acetate as the electron donor. Cell suspensions of PCA exhibited dithionite-reduced minus air-oxidized difference spectra which were characteristic of c-type cytochromes. Phylogenetic analysis of the 16S rRNA sequence placed PCA in the delta subgroup of the proteobacteria. Its closest known relative is Geobacter metallireducens. The ability to utilize either hydrogen or acetate as the sole electron donor for Fe(III) reduction makes strain PCA a unique addition to the relatively small group of respiratory metal-reducing microorganisms available in pure culture. A new species name, Geobacter sulfurreducens, is proposed. C1 UNIV OKLAHOMA,DEPT BOT & MICROBIOL,NORMAN,OK 73019. DUQUESNE UNIV,DEPT BIOL SCI,PITTSBURGH,PA 15282. US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. RI McInerney, Michael/E-6215-2012 NR 46 TC 450 Z9 464 U1 5 U2 96 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 1994 VL 60 IS 10 BP 3752 EP 3759 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA PK266 UT WOS:A1994PK26600041 PM 7527204 ER PT J AU HENRY, CJ HIGGINS, KF BUHL, KJ AF HENRY, CJ HIGGINS, KF BUHL, KJ TI ACUTE TOXICITY AND HAZARD ASSESSMENT OF RODEO(R), X-77 SPREADER(R), AND CHEM-TROL(R) TO AQUATIC INVERTEBRATES SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID GLYPHOSATE; HERBICIDES; WETLANDS; DAKOTA; FISH AB The herbicide Rodeo(R) provides waterfowl managers with an effective chemical tool for creating open water habitats in wetlands if its use does not adversely affect native invertebrate communities. The survival of caged Chironomus spp. (midge), Hyalella azteca (amphipod), Stagnicola elodes (pond snail), and Nephelopsis obscura (leech) was assessed in prairie pothole wetlands treated by air with a tank mixture of Rodeo(R), the surfactant X-77 Spreader(R), and the drift retardant Chem-Trol(R) at a rate recommended for controlling cattails. Laboratory studies were then conducted to determine the acute toxicities of Rodeo(R), X-77 Spreader(R), and Chem-trol(R), individually and in simulated tank mixtures, to the same invertebrates and to Daphnia magna in reconstituted water representative of these wetlands. There was no difference in the survival of caged invertebrates between treated and reference wetlands after 21 days. Based on nominal concentrations of the formulations, X-77 Spreader(R) (LC50s = 2.0-14.1 mg/L) was about 83-136 times more toxic than Rodeo(R) (Lc50s = 218-1216 mg/L) to aquatic invertebrates. Chem-Trol(R) killed less than or equal to 10% of the animals at 10,000 mg/L and less than or equal to 50% of the animals at 28,000 mg/L. Daphnia magna were more sensitive than the other species to X-77 Spreader(R), Rodeo(R), and the simulated Rodeo(R) tank mixture (RTM). The joint toxic action of the RTM was additive for amphipods and midges, greater than additive for leeches, and was less than additive for daphnids. X-77 Spreader(R) was the major toxic component in the RTM. Binary mixtures of X-77 Spreader(R), Rodeo(R), and Chem-Trol(R) at tank mixture and equitoxic ratios also showed additive toxicity to amphipods. The use of Rodeo(R) (applied as tank mixture with X-77 Spreader(R) and Chem-Trol(R)) as a management tool in wetlands does not pose an acute hazard to native aquatic invertebrates because the concentrations of Rodeo(R), X-77 Spreader(R), and Chem-Trol(R) found to be acutely toxic to these invertebrates were much higher than their expected or measured concentrations in water from wetlands treated with the RTM. C1 S DAKOTA STATE UNIV, US FISH & WILDLIFE SERV, S DAKOTA COOPERAT FISH & WILDLIFE RES UNIT, BROOKINGS, SD 57007 USA. US FISH & WILDLIFE SERV, NATL FISHERIES CONTAMINANT RES CTR, YANKTON FIELD RES STN, YANKTON, SD 57078 USA. NR 35 TC 24 Z9 25 U1 0 U2 4 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 1994 VL 27 IS 3 BP 392 EP 399 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA PD585 UT WOS:A1994PD58500016 ER PT J AU SPENDELOW, JA BURGER, J NISBET, ICT NICHOLS, JD HINES, JE HAYS, H CORMONS, GD GOCHFELD, M AF SPENDELOW, JA BURGER, J NISBET, ICT NICHOLS, JD HINES, JE HAYS, H CORMONS, GD GOCHFELD, M TI SOURCES OF VARIATION IN LOSS RATES OF COLOR BANDS APPLIED TO ADULT ROSEATE-TERNS (STERNA-DOUGALLII) IN THE WESTERN NORTH-ATLANTIC SO AUK LA English DT Article ID ANNUAL SURVIVAL RATES; COMMON TERNS; WEAR AB A model-based analysis was done to test several hypotheses concerning the rates of loss of butt-ended color bands placed on adult Roseate Terns (Sterna dougallii) in the western North Atlantic. These birds were captured and color banded from 1987-1991 at four colony sites, and recaptured from 1989-1992 as part of a study of the population dynamics of this species. Two types of color bands, Darvic and celluloid, were used, but only one band type was used for each individual bird. Each bird was given three color bands. The estimated probability that a bird with all color bands present during one breeding season still had all color bands during the next breeding season was 0.87. The analysis provided no evidence that colony site, cohort, calendar year of banding, age of color band, or whether or not the bands were heat-sealed closed, were important sources of variation in band-retention probabilities. C1 RUTGERS STATE UNIV,DEPT BIOL SCI,PISCATAWAY,NJ 08855. ICT NISHET & CO,N FALMOUTH,MA 02556. AMER MUSEUM NAT HIST,GREAT GULL ISL PROJECT,NEW YORK,NY 10024. UNIV MED & DENT NEW JERSEY,ROBERT WOOD JOHNSON MED SCH,PISCATAWAY,NJ 08854. RP SPENDELOW, JA (reprint author), US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,BRANCH MIGRATORY BIRD RES,LAUREL,MD 20708, USA. NR 32 TC 14 Z9 14 U1 0 U2 2 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 1994 VL 111 IS 4 BP 881 EP 887 PG 7 WC Ornithology SC Zoology GA RX856 UT WOS:A1994RX85600010 ER PT J AU PIATT, JF GOULD, PJ AF PIATT, JF GOULD, PJ TI POSTBREEDING DISPERSAL AND DRIFT-NET MORTALITY OF ENDANGERED JAPANESE MURRELETS SO AUK LA English DT Article ID KUROSHIO AB The incidental catch of seabirds in high-seas drift nets was recorded in 1990-1991 by scientific observers on commercial squid and large-mesh fishery vessels operating in the North Pacific Transitional Zone. Twenty-six Synthliboramphus murrelet deaths were recorded in the months of August through December. All but one were from the Korean squid fishery in a small area bounded by 38 degrees-44 degrees N and 142 degrees-157 degrees E. Five specimens of the dead birds were collected and later identified as Japanese Murrelets (S, wumizusume). As fishing effort was widely distributed over a large area east of Japan, these data suggest that postbreeding Japanese Murrelets migrate north to winter in a relatively small area southeast of Hokkaido, where persistent eddies form at the confluence of the Oyashio and Kuroshio currents. Fronts between cold Oyashio water and Kuroshio warm-core eddies promote the aggregation of zooplankton and pelagic fishes, which in turn may attract murrelets during the nonbreeding season. The estimated total mortality of Japanese Murrelets in high-seas drift-net fisheries represents a significant proportion of the total world population of this rare and endangered species. RP PIATT, JF (reprint author), US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,NATL BIOL SERV,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. NR 33 TC 11 Z9 12 U1 0 U2 0 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 1994 VL 111 IS 4 BP 953 EP 961 PG 9 WC Ornithology SC Zoology GA RX856 UT WOS:A1994RX85600017 ER PT J AU NEIGER, RD JOHNSON, TJ HURLEY, DJ HIGGINS, KF ROTTINGHAUS, GE STAHR, H AF NEIGER, RD JOHNSON, TJ HURLEY, DJ HIGGINS, KF ROTTINGHAUS, GE STAHR, H TI THE SHORT-TERM EFFECT OF LOW CONCENTRATIONS OF DIETARY ANATOXIN AND T-2 TOXIN ON MALLARD DUCKLINGS SO AVIAN DISEASES LA English DT Article DE DUCKS; MYCOTOXIN; ANATOXIN; T-2 TOXIN; WEIGHT LOSS; LYMPHOID SYSTEM ID CHICKENS AB Two 9-day trials to study effects of dietary mycotoxins were conducted using 6-week-old mallards. Each trial involved three groups of six ducks each, three males and three females per group. One group was fed no mycotoxin (control), one was fed anatoxin, and the third was fed T-2 toxin. Dietary anatoxin was 12 ppb in trial 1 and 33 ppb in trial 2; dietary T-2 toxin was 2 ppm in both trials. There were no gross or microscopic lesions in controls or in ducks fed anatoxin, nor did these groups differ significantly in final body weight or in weights of spleen or bursa of Fabricius. Ducks exposed to T-2 toxin had erosions and/ or ulcerations in the oral cavity and esophagus; further, these ducks exhibited a decrease in weights of body, thymus, spleen, and bursa of Fabricius. The only microscopic change seen in lymphoid organs of ducks exposed to T-2 toxin was a moderate decrease of thymic cortical lymphocytes. C1 S DAKOTA STATE UNIV,US FISH & WILDLIFE SERV,DEPT BIOL & MICROBIOL,BROOKINGS,SD 57007. S DAKOTA STATE UNIV,US FISH & WILDLIFE SERV,S DAKOTA COOPERAT FISH & WILDLIFE RES UNIT,BROOKINGS,SD 57007. UNIV MISSOURI,COLL VET MED,VET MED DIAGNOST LAB,COLUMBIA,MO 65211. IOWA STATE UNIV SCI & TECHNOL,COLL VET MED,VET MED DIAGNOST LAB,AMES,IA 50011. RP NEIGER, RD (reprint author), S DAKOTA STATE UNIV,US FISH & WILDLIFE SERV,DEPT VET SCI,BOX 2140B,BROOKINGS,SD 57007, USA. NR 14 TC 16 Z9 17 U1 0 U2 0 PU AMER ASSOC AVIAN PATHOLOGISTS PI KENNETT SQ PA UNIV PENN, NEW BOLTON CENTER, KENNETT SQ, PA 19348-1692 SN 0005-2086 J9 AVIAN DIS JI Avian Dis. PD OCT-DEC PY 1994 VL 38 IS 4 BP 738 EP 743 DI 10.2307/1592109 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA PZ318 UT WOS:A1994PZ31800007 PM 7702506 ER PT J AU HARTZELL, SH CARVER, DL KING, KW AF HARTZELL, SH CARVER, DL KING, KW TI INITIAL INVESTIGATION OF SITE AND TOPOGRAPHIC EFFECTS AT ROBINWOOD RIDGE, CALIFORNIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LOMA-PRIETA AFTERSHOCKS; EARTHQUAKE; ARRAY; PROPAGATION; INVERSION; MOTION AB Following the 1989 Loma Prieta earthquake, a dense array of seven digitally recorded, three-component seismograph stations was deployed on Robinwood Ridge 7.3 km northwest of the epicenter. The purpose of this array was to investigate the cause of high levels of structural damage and ground cracking observed on the ridge crest. Aftershocks recorded by the array allow a comparison of ground motion up the slope of the ridge from the base to the crest. The data present an extremely complicated pattern of ground motion that demonstrates the importance of the three-dimensionality of the problem. Slowness analysis of P wave trains show initial arrivals propagating away from the source with small angles of incidence and large apparent velocities, consistent with direct arrivals. After 0.5 sec, propagation azimuths become more random and apparent velocities drop, indicating nearly horizontal wave propagation and multiply reflected and diffracted phases within the ridge. Slowness analysis and particle motion diagrams of horizontal components of motion show dramatic variations in ground motion with changes in azimuth of the source and a complicated interaction between body waves and Rayleigh and Love waves. Results suggest that the larger amplitude, more coherent arrivals at the array stations favor a propagation direction parallel to the ridge axis. An amplification factor of from 1.5 to 4.5 is seen for frequencies from 1.0 to 3.0 Hz with wavelengths comparable to the base of the ridge, part of which may be caused by local site effects and part by topographic amplification. In addition, amplifications of up to a factor of 5 are seen at higher frequencies and are attributed to local site effects. These effects are most notable from 4 to 8 Hz on the vertical components, and from 6 to 9 Hz on the horizontal components. The entire Robinwood Ridge area may also have been situated in a region of heightened mainshock ground motion due to source directivity and radiation pattern effects. RP HARTZELL, SH (reprint author), US GEOL SURVEY,EARTHQUAKE & LANDSLIDE HAZARDS BRANCH,DENVER,CO 80255, USA. NR 13 TC 55 Z9 68 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 OCT PY 1994 VL 84 IS 5 BP 1336 EP 1349 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QW649 UT WOS:A1994QW64900004 ER PT J AU HARMSEN, SC AF HARMSEN, SC TI THE LITTLE-SKULL-MOUNTAIN, NEVADA, EARTHQUAKE OF 29-JUNE-1992 - AFTERSHOCK FOCAL MECHANISMS AND TECTONIC STRESS-FIELD IMPLICATIONS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN GREAT-BASIN; UNITED-STATES; SLIP DATA; TENSOR; FAULTS; DEFORMATION; CALIFORNIA; EXTENSION; FRICTION; SEQUENCE AB The M(L) = 5.6 29 June 1992 Little Skull Mountain earthquake occurred in the southern Nevada Test Site, Nye County, Nevada, within 20 km of a potential national nuclear waste repository at Yucca Mountain, Nevada. While microseismicity in the immediate epicentral vicinity occurred for years prior to the mainshock, foreshock activity (M(L) < 2) sharply increased following the Landers, California, earthquake of 28 June, 22 hr before the Little Skull Mountain earthquake. Approximately 3000 aftershocks were located in the period June through September 1992, and their hypocenters suggest activity on two major and several minor faults with different orientations. Seventy aftershocks in June and July 1992 had magnitudes M(L) greater than or equal to 3.0, and several smaller aftershocks (M(L) > 2) were also sufficiently well recorded to provide local network P-wave focal-mechanism solutions. The mainshock and the majority of the aftershocks through September 1992 display predominantly normal-slip focal mechanisms, but unambiguous strike-slip and oblique-slip focal-mechanism solutions are also present in the aftershock series. The mainshock and immediate foreshock depths were 10 +/- 1 km below sea level, and depths of focus of aftershocks range from about 6 to 12 km. A large subset of the aftershock hypocenters define a southeast-dipping structure, probably the mainshock fault plane. No variation of mechanism style with depth is apparent. Two mainshock and 84 aftershock focal-mechanism solutions were input into Gephart's (1990) stress-field inversion program, and principal compressional stress directions, sigma(j), j = 1, 2, 3, were determined, as well as the stress difference ratio R = (sigma(1) - sigma(2))/(sigma(1) - sigma(3)). The results indicate a uniform stress field in which sigma(3) (minimum stress) is oriented 116 degrees/5 degrees (azi, plunge) and sigma(1) (maximum stress) is oriented 219 degrees/69 degrees with R = 0.35. The inversion's selection of preferred nodal planes invokes Bott's (1959) criterion, which states that slip occurs in the direction of resolved shear traction on preexisting fault surfaces. For the predominantly normal-slip Little Skull Mountain earthquake mechanisms having similar to northeast-striking planes, the southeast, moderately to steeply dipping (dip > 55 degrees) nodal planes are selected. However, for the dip-slip earthquake mechanisms exhibiting more northerly trending strikes, shallowly to moderately west-dipping (25 degrees < dip < 65 degrees) nodal planes are selected. When a Coulomb-Mohr analysis was applied to the focal mechanisms using the above principal stress directions and an assumed ratio sigma(1)/sigma(3), the ratio of resolved shear stress to normal stress, tau/sigma(n), on the southeast-dipping nodal plane of the mainshock exhibited a near-maximum level, suggesting a high fault strength. In contrast, a wide range of fault strengths, or apparent coefficients of friction, was suggested by the tau/sigma(n) ratios for Little Skull Mountain aftershock preferred nodal planes. Seismicity on misoriented faults, i.e., those on which shear stress was relatively low, may have been the result of a temporarily elevated fluid pore pressure following the mainshock. RP HARMSEN, SC (reprint author), US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225, USA. NR 53 TC 21 Z9 21 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 1994 VL 84 IS 5 BP 1484 EP 1505 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA QW649 UT WOS:A1994QW64900013 ER PT J AU DZURISIN, D YAMASHITA, KM KLEINMAN, JW AF DZURISIN, D YAMASHITA, KM KLEINMAN, JW TI MECHANISMS OF CRUSTAL UPLIFT AND SUBSIDENCE AT THE YELLOWSTONE CALDERA, WYOMING SO BULLETIN OF VOLCANOLOGY LA English DT Article DE CALDERA UNREST; VOLCANO GEODESY; UPLIFT; SUBSIDENCE; HYDROTHERMAL SYSTEM; MAGMATIC INTRUSION; YELLOWSTONE AB Leveling surveys in 1923, 1976, and each year from 1983 to 1993 have shown that the east-central part of the Yellowstone caldera, near the base of the Sour Creek resurgent dome, rose at an average rate of 14 +/- 1 mm/year from 1923 to 1976 and 22 +/- 1 mm/year from 1976 to 1984. In contrast, no detectable movement occurred in the same area from 1984 to 1985 (- 2 +/- 5 mm/year), and from 1985 to 1993 the area subsided at an average rate of 19 +/- 1 mm/year. We conclude that uplift from 1923 to 1984 was caused by: (1) pressurization of the deep hydrothermal system by fluids released from a crystallizing body of rhyolite magma beneath the caldera, then trapped beneath a self-sealed zone near the base of the hydrothermal system; and (2) aseismic intrusions of magma into the lower part of the sub-caldera magma body. Subsidence since 1985 is attributed to: (1) depressurization and fluid loss from the deep hydrothermal system, and (2) sagging of the caldera floor in response to regional crustal extension. Future intrusions might trigger renewed eruptive activity at Yellowstone, but most intrusions at large silicic calderas seem to be accommodated without eruptions. Overpressurization of the deep hydrothermal system could conceivably result in a phreatic or phreatomagmatic eruption, but this hazard is mitigated by episodic rupturing of the self-sealed zone during shallow earthquake swarms. Historical ground movements, although rapid by most geologic standards, seem to be typical of inter-eruption periods at large, mature, silicic magma systems like Yellowstone. The greatest short-term hazards posed by continuing unrest in the Yellowstone region are: (1) moderate to large earthquakes (magnitude 5.5-7.5), with a recurrence interval of a few decades; and (2) small hydrothermal explosions, most of which affect only a small area (< 0.01 km2), with a recurrence interval of a few years. RP DZURISIN, D (reprint author), US GEOL SURVEY,DAVID A JOHNSTON CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 0 TC 54 Z9 54 U1 1 U2 13 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD OCT PY 1994 VL 56 IS 4 BP 261 EP 270 DI 10.1007/BF00302079 PG 10 WC Geosciences, Multidisciplinary SC Geology GA PP618 UT WOS:A1994PP61800002 ER PT J AU EICHORN, C AF EICHORN, C TI MENYAILOV,IGOR,ALEKSANDROVICH - (1937-1993) SO BULLETIN OF VOLCANOLOGY LA English DT Item About an Individual RP EICHORN, C (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0258-8900 J9 B VOLCANOL JI Bull. Volcanol. PD OCT PY 1994 VL 56 IS 4 BP 314 EP 315 PG 2 WC Geosciences, Multidisciplinary SC Geology GA PP618 UT WOS:A1994PP61800007 ER PT J AU LEAVESLEY, GH AF LEAVESLEY, GH TI MODELING THE EFFECTS OF CLIMATE-CHANGE ON WATER-RESOURCES - A REVIEW SO CLIMATIC CHANGE LA English DT Article ID RAINFALL-RUNOFF MODELS; SYSTEME-HYDROLOGIQUE-EUROPEEN; ATMOSPHERIC CARBON-DIOXIDE; EPIC MODEL; BALANCE; SENSITIVITY; SCALE; CO2; STREAMFLOW; BASIN AB Hydrologic models provide a framework in which to conceptualize and investigate the relationships between climate and water resources. A review of current studies that assess the impacts of climate change using hydrologic models indicates a number of problem areas common to the variety of models applied. These problem areas include parameter estimation, scale, model validation, climate scenario generation, and data. Research needs to address these problems include development of (1) a more physically based understanding of hydrologic processes and their interactions; (2) parameter measurement and estimation techniques for application over a range of spatial and temporal scales; (3) quantitative measures of uncertainty in model parameters and model results; (4) improved methodologies of climate scenario generation; (5) detailed data sets in a variety of climatic and physiographic regions; and (6) modular modeling tools to provide a framework to facilitate interdisciplinary research. Solutions to these problems would significantly improve the capability of models to assess the effects of climate change. RP LEAVESLEY, GH (reprint author), US DEPT INTERIOR,DENVER FED CTR,GEOL SURVEY,BOX 25046,MS 412,DENVER,CO 80225, USA. NR 65 TC 110 Z9 111 U1 3 U2 22 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 OCT PY 1994 VL 28 IS 1-2 BP 159 EP 177 DI 10.1007/BF01094105 PG 19 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA PQ757 UT WOS:A1994PQ75700008 ER PT J AU NICHOLS, JD HINES, JE POLLOCK, KH HINZ, RL LINK, WA AF NICHOLS, JD HINES, JE POLLOCK, KH HINZ, RL LINK, WA TI ESTIMATING BREEDING PROPORTIONS AND TESTING HYPOTHESES ABOUT COSTS OF REPRODUCTION WITH CAPTURE-RECAPTURE DATA SO ECOLOGY LA English DT Article DE CAPTURE SIGHTING PROBABILITY; MICROTUS PENNSYLVANICUS; MULTISTATE CAPTURE RECAPTURE MODELS; PROPORTION OF ANIMALS BREEDING; REPRODUCTIVE COSTS; SURVIVAL RATE ID POPULATION-SIZE; SURVIVAL; RATES; RECOVERY; PROBABILITIES; MODELS; GEESE; AGE AB The proportion of animals in a population that breeds is an important determinant of population growth rate. Usual estimates of this quantity from field sampling data assume that the probability of appearing in the capture or count statistic is the same for animals that do and do not breed. A similar assumption is required by most existing methods used to test ecologically interesting hypotheses about reproductive costs using field sampling data. However, in many field sampling situations breeding and nonbreeding animals are likely to exhibit different probabilities of being seen or caught. In this paper, we propose the use of multistate capture-recapture models for these estimation and testing problems. This methodology permits a formal test of the hypothesis of equal capture/sighting probabilities for breeding and nonbreeding individuals. Two estimators of breeding proportion (and associated standard errors) are presented, one for the case of equal capture probabilities and one for the case of unequal capture probabilities. The multistate modeling framework also yields formal tests of hypotheses about reproductive costs to future reproduction or survival or both fitness components. The general methodology is illustrated using capture-recapture data on female meadow voles, Microtus pennsylvanicus. Resulting estimates of the proportion of reproductively active females showed strong seasonal variation, as expected, with low breeding proportions in midwinter. We found no evidence of reproductive costs extracted in subsequent survival or reproduction. We believe that this methodological framework has wide application to problems in animal ecology concerning breeding proportions and phenotypic reproductive costs. C1 N CAROLINA STATE UNIV, INST STAT, RALEIGH, NC 27695 USA. RP NICHOLS, JD (reprint author), US FISH & WILDLIFE SERV, PATUXENT WILDLIFE RES CTR, NATL BIOL SURVEY, LAUREL, MD 20708 USA. NR 41 TC 160 Z9 162 U1 3 U2 32 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 EI 1939-9170 J9 ECOLOGY JI Ecology PD OCT PY 1994 VL 75 IS 7 BP 2052 EP 2065 DI 10.2307/1941610 PG 14 WC Ecology SC Environmental Sciences & Ecology GA PK129 UT WOS:A1994PK12900020 ER PT J AU CHIN, YP AIKEN, G OLOUGHLIN, E AF CHIN, YP AIKEN, G OLOUGHLIN, E TI MOLECULAR-WEIGHT, POLYDISPERSITY, AND SPECTROSCOPIC PROPERTIES OF AQUATIC HUMIC SUBSTANCES SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID DISSOLVED ORGANIC-MATTER; POLYCYCLIC AROMATIC-HYDROCARBONS; MACROPOROUS RESINS; FULVIC-ACIDS; BINDING; WATER; CHROMATOGRAPHY; SEDIMENTS; SEAWATER; COLLOIDS AB The number- and weight-averaged molecular weights of a number of aquatic fulvic acids, a commercial humic acid, and unfractionated organic matter from four natural water samples were measured by high-pressure size exclusion chromatography (HPSEC). Molecular weights determined in this manner compared favorably with those values reported in the literature. Both recent literature values and our data indicate that these substances are smaller and less polydisperse than previously believed. Moreover, the molecular weights of the organic matter from three of the four natural water samples compared favorably to the fulvic acid samples extracted from similar environments. Bulk spectroscopic properties of the fulvic substances such as molar absorptivity at 280 nm and the E(4)/E(6) ratio were also measured. A strong correlation was observed between molar absorptivity, total aromaticity, and the weight average molecular weights of all the humic substances. This observation suggests that bulk spectroscopic properties can be used to quickly estimate the size of humic substances and their aromatic contents. Both parameters are important with respect to understanding humic substance mobility and their propensity to react with both organic and inorganic pollutants. C1 US GEOL SURVEY,DIV WATER RESOURCES,BOULDER,CO 80303. OHIO STATE UNIV,ENVIRONM SCI PROGRAM,COLUMBUS,OH 43210. RP CHIN, YP (reprint author), OHIO STATE UNIV,DEPT GEOL SCI,COLUMBUS,OH 43210, USA. RI O'Loughlin, Edward/C-9565-2013 OI O'Loughlin, Edward/0000-0003-1607-9529 NR 45 TC 1106 Z9 1188 U1 40 U2 373 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1994 VL 28 IS 11 BP 1853 EP 1858 DI 10.1021/es00060a015 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PK069 UT WOS:A1994PK06900019 PM 22175925 ER PT J AU FLUETSCH, KM SPARLING, DW AF FLUETSCH, KM SPARLING, DW TI AVIAN NESTING SUCCESS AND DIVERSITY IN CONVENTIONALLY AND ORGANICALLY MANAGED APPLE ORCHARDS SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE MOURNING DOVES; AMERICAN ROBINS; ORCHARDS; ORGANOPHOSPHORUS PESTICIDES; NESTING SUCCESS ID BIRDS; FENITROTHION; PESTICIDE; EMBRYOTOXICITY; TERATOGENICITY; INSECTICIDES; REPRODUCTION; CONTAMINANTS; SONGBIRDS; BEHAVIOR AB This study examines the effects of operational use of pesticides on avian species inhabiting apple orchards in Pennsylvania. Mourning dove (Zenaida macroura) and American robin (Turdus migratorius) nests were monitored in three organic and three Conventional apple orchards during 1990 and 1991. In 1991 we surveyed the avian communities of these orchards by using line transects. Organophosphorus (OF) (e.g., azinphos-methyl, phosphamidon, parathion, dimethoate), carbamate (CA) (e.g., methomyl, formetanate, oxamyl), and organochlorine (endosulfan) pesticides, known to be highly toxic to birds, were sprayed individually or in mixtures as part of routine pest management as many as 19 times during peaks in breeding activity. Spray card tests revealed that OP pesticides were deposited on 86% of the nests in conventional orchards. Daily survival rates (DSRs) for nests of both species were higher in the organic orchards than in the conventional orchards for 1991 and for years combined (p < 0.05). Species diversity was greater in the organic orchards ((H) over cap = 2.43) than in the conventional orchards ((H) over cap = 1.79). Repeated applications of pesticides within the conventional orchards reduced the reproductive success of doves and robins and may have lowered avian species diversity Compared with organic orchards. C1 NATL BIOL SURVEY,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. US FISH & WILDLIFE SERV,NO ALASKA ECOL SERV,FAIRBANKS,AK 99701. NR 46 TC 16 Z9 16 U1 2 U2 17 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 OCT PY 1994 VL 13 IS 10 BP 1651 EP 1659 DI 10.1897/1552-8618(1994)13[1651:ANSADI]2.0.CO;2 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA PH803 UT WOS:A1994PH80300015 ER PT J AU PAJAK, P AF PAJAK, P TI URBAN OUTREACH - FISHERY MANAGEMENTS NEXT FRONTIER SO FISHERIES LA English DT Article RP PAJAK, P (reprint author), US FISH & WILDLIFE SERV,DIV FED AID,FT SNELLING,MN, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD OCT PY 1994 VL 19 IS 10 BP 6 EP 7 PG 2 WC Fisheries SC Fisheries GA PJ583 UT WOS:A1994PJ58300002 ER PT J AU DOROFF, AM DEGANGE, AR AF DOROFF, AM DEGANGE, AR TI SEA OTTER, ENHYDRA-LUTRIS, PREY COMPOSITION AND FORAGING SUCCESS IN THE NORTHERN KODIAK ARCHIPELAGO SO FISHERY BULLETIN LA English DT Article ID DIVING SUCCESS; TIME BUDGETS; PREDATION; ALASKA AB During 1987 and 1988, sea otter, Enhydra lutris, prey composition and foraging success were studied by observing foraging otters in the northern Kodiak Archipelago. Study areas differed in the number of years in which they were occupied by sea otters and were categorized as established (occupied >25 years), intermediate (occupied 5-15 years), and frontal (occupied <5 years). Clams were the most frequently identified sea otter prey (57-67%) in all study areas, and of the clams identified to species, Saxidomus giganteus was the most frequently observed. Mussels, Mytilus spp., crabs (primarily Telmessus spp.), and green sea urchins, Strongylocentrotus droebachiensis, contributed less than or equal to 25% to the total prey within each study area. Adults did not differ in the proportion of calms, mussels, or crabs captured as prey among study areas. Adults captured clams with a greater frequency and mussels with lesser frequency than did juvenile sea otters for all study areas combined. Forage success did not differ among study areas for adults nor between adults and juveniles for all study areas combined. Adult sea otters in the established area appear to have compensated for reduced prey size by retrieving more prey items per dive; however, they obtained less clam biomass per dive than otters in the intermediate and frontal areas. RP DOROFF, AM (reprint author), US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. NR 22 TC 17 Z9 18 U1 1 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1994 VL 92 IS 4 BP 704 EP 710 PG 7 WC Fisheries SC Fisheries GA PL097 UT WOS:A1994PL09700004 ER PT J AU BALISTRIERI, LS MURRAY, JW PAUL, B AF BALISTRIERI, LS MURRAY, JW PAUL, B TI THE GEOCHEMICAL CYCLING OF TRACE-ELEMENTS IN A BIOGENIC MEROMICTIC LAKE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SEASONALLY ANOXIC LAKE; AMORPHOUS IRON OXYHYDROXIDE; NATURAL-WATERS; HUMIC SUBSTANCES; EUTROPHIC LAKE; METAL DYNAMICS; BALTIC WATERS; MANGANESE; ADSORPTION; SULFIDE AB The geochemical processes affecting the behavior and speciation of As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn in Hall Lake, Washington, USA, are assessed by examining dissolved and acid soluble particulate profiles of the elements and utilizing results from thermodynamic calculations. The water column of this meromictic lake is highly stratified and contains distinctive oxic, suboxic, and anoxic layers. Changes in the redox state of the water column with depth affect the distribution of all the elements studied. Most noticeable are increases in dissolved Co, Cr, Fe, Mn, Ni, Pb, and Zn concentrations across the oxic-suboxic boundary, increases in dissolved As, Co, Cr, Fe, Mn, and V concentrations with depth in the anoxic layer, significant decreases in dissolved Cu, Ni, Pb, and Zn concentrations in the anoxic region below the sulfide maximum, and large increases in acid soluble particulate concentrations of As, Cr, Cu, Fe, Mo, Ni, Pb, V, and Zn in the anoxic zone below the sulfide maximum. Thermodynamic calculations for the anoxic region indicate that all redox sensitive elements exist in their reduced forms, the primary dissolved forms of Cu, Ni, Pb, and Zn are metal sulfide solution complexes, and solid sulfide phases of Cu, Fe, Mo, and Pb are supersaturated. Calculations using a vertical diffusion and reaction model indicate that the oxidation rate constant for Mn(II) in Hall Lake is estimated to be 0.006 d(-1) and is at the lower end of the range of microbial oxidation rates observed in other natural systems. The main geochemical processes influencing the distribution and speciation of trace elements in Hall Lake appear to be transformations of dissolved elements between their oxidation states (As, Cr, Cu, Fe, Mn, V), cocycling of trace elements with Mn and Fe (As, Co, Cr, Cu, Mo, Ni, Pb, V, Zn), formation of soluble metal sulfide complexes (Co, Cu, Ni, Pb, Zn), sorption (As, Co, Cr, Ni, V), and precipitation (Cu, Fe, Mn, Mo, Pb, Zn). RP BALISTRIERI, LS (reprint author), UNIV WASHINGTON,SCH OCEANOG,US GEOL SURVEY,SEATTLE,WA 98195, USA. OI Murray, James/0000-0002-8577-7964 NR 73 TC 111 Z9 113 U1 2 U2 25 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 1994 VL 58 IS 19 BP 3993 EP 4008 DI 10.1016/0016-7037(94)90262-3 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PK700 UT WOS:A1994PK70000003 ER PT J AU WALKER, RJ MORGAN, JW HORAN, MF CZAMANSKE, GK KROGSTAD, EJ FEDORENKO, VA KUNILOV, VE AF WALKER, RJ MORGAN, JW HORAN, MF CZAMANSKE, GK KROGSTAD, EJ FEDORENKO, VA KUNILOV, VE TI RE-OS ISOTOPIC EVIDENCE FOR AN ENRICHED-MANTLE SOURCE FOR THE NORILSK-TYPE, ORE-BEARING INTRUSIONS, SIBERIA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PERMIAN-TRIASSIC BOUNDARY; FLOOD-BASALT VOLCANISM; TRACE-ELEMENT; OCEANIC BASALTS; GORGONA-ISLAND; SULFIDE ORES; SR-ISOTOPE; ND-ISOTOPE; RB-SR; OSMIUM AB Magmatic Cu-Ni sulfide ores and spatially associated ultramafic and mafic rocks from the Noril'sk I, Talnakh, and Kharaelakh intrusions are examined for Re-Os isotopic systematics. Neodymium and lead isotopic data also are reported for the: ultramafic and mafic rocks. The Re-Os data for most samples indicate closed-system behavior since the ca. 250 Ma igneous crystallization age of the intrusions. There are small but significant differences in thr: initial osmium isotopic compositions of samples from the three intrusions. Ores from the Noril'sk I intrusion have gamma(Os) values that vary from +0.4 to +8.8, but average +5.8. Ores from the Talnakh intrusion have gamma(Os) values that range from +6.7 to +8.2, averaging +7.7. Ores from the Kharaelakh intrusion have gamma(Os) values that range from +7.8 to +12.9, with an average value of +10.4. The osmium isotopic compositions of the ore samples from the Main Kharaelakh orebody exhibit minimal overlap with those for the Noril'sk I and Talnakh intrusions, indicating that these Kharaelakh ores were derived from a more radiogenic source of osmium than the other ores. Combined osmium and lead data for major orebodies in the three intrusions plot in three distinct fields, indicating derivation of osmium and lead from at least three isotopically distinct sources. Some of the variation in lead isotopic compositions may be the result of minor lower-crustal contamination. However, in contrast to most other isotopic and trace element data, Os-Pb variations are generally inconsistent with significant crustal contamination or interaction with the subcontinental lithosphere. Thus, the osmium and lead isotopic compositions of these intrusions probably reflect quite closely the compositions of their mantle source, and suggest that these two isotope systems were insensitive to lithospheric interaction. Ultramafic and mafic rocks have osmium and lead isotopic compositions that range only slightly beyond the compositions of the ores. These rocks also have relatively uniform epsilon(Nd) values that range only from -0.8 to +1.1. This limited variation in neodymium isotopic composition may reflect the characteristics of the mantle sources of the rocks; or it may indicate that somehow similar proportions of crust contaminated the parental melts. The osmium, lead, and neodymium isotopic, data for these rocks most closely resemble the mantle sources of certain ocean island basalts (GIB), such as some Hawaiian basalts. Hence, these data are consistent with derivation of primary melts from a mantle source similar to that of some types of hotspot activity. The long-term Re/Os enrichment of this and similar mantle sources, relative to chondritic upper mantle, may reflect (1) incorporation of recycled oceanic crust into the source more than 1 Ga ago, (2) derivation from a mantle plume that originated at the outer core-lower mantle interface, or(3) persistence of primordial stratification of rhenium and osmium in the mantle. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,RESTON,VA 22092. CENT RES INST GEOL PROSPECTING BASE & PRECIOUS ME,MOSCOW 113545,RUSSIA. NORILSK NICKEL CONCERN,NORILSK 663300,RUSSIA. RP WALKER, RJ (reprint author), UNIV MARYLAND,DEPT GEOL,ISOTOPE GEOCHEM LAB,COLLEGE PK,MD 20742, USA. RI Walker, Richard/K-6869-2016 OI Walker, Richard/0000-0003-0348-2407 NR 77 TC 154 Z9 179 U1 0 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 OCT PY 1994 VL 58 IS 19 BP 4179 EP 4197 DI 10.1016/0016-7037(94)90272-0 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PK700 UT WOS:A1994PK70000013 ER PT J AU OSTERKAMP, WR TOY, TJ AF OSTERKAMP, WR TOY, TJ TI THE HEALING OF DISTURBED HILLSLOPES BY GULLY GRAVURE SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID EROSION AB Results of accelerated erosion on certain constructed surfaces in southeastern Arizona appear similar to those described by Bryan (1940) as gully gravure. Twenty cross-section excavations in eight rills incised into silt-rich lacustrine and fluvial deposits reveal partial filling of the rills by debris derived from overlying fluvial sand, gravel, and cobbles. Interstices of the coarse material gradually fill with fine-grained erosion products, decreasing permeability of the fill and deflecting subsequent runoff to the margins of the fill. Rills and rill fillings thus increase in width with time, and complete veneering of the surface by coarse debris ultimately may occur. Through incision, filling, lateral planation, and armoring, channels of the dissected surface heal and the new hillslope approaches an equilibrium condition. Natural hillslopes in the area with similar geologic conditions have inclinations of 16-degrees-22-degrees, have generally unbroken veneers of coarse debris, and appear subject to the same erosional processes identified at constructed hillslopes. Field measurements and the revised universal soil loss equation (RUSLE) were used to estimate soil loss on natural and constructed hillslopes. Results suggest that erosion may be almost three orders of magnitude greater on steep, nonveneered, nonvegetated constructed surfaces than on natural hillslopes. Attributes of stable natural hillslopes provide criteria for the design of stable constructed hillslopes. C1 UNIV DENVER,DEPT GEOG,DENVER,CO 80208. RP OSTERKAMP, WR (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MS 413,POB 25046,DENVER,CO 80225, USA. NR 27 TC 6 Z9 6 U1 0 U2 0 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 OCT PY 1994 VL 106 IS 10 BP 1233 EP 1241 DI 10.1130/0016-7606(1994)106<1233:THODHB>2.3.CO;2 PG 9 WC Geosciences, Multidisciplinary SC Geology GA PJ579 UT WOS:A1994PJ57900001 ER PT J AU FLECK, RJ MATTINSON, JM BUSBY, CJ CARR, MD DAVIS, GA BURCHFIEL, BC AF FLECK, RJ MATTINSON, JM BUSBY, CJ CARR, MD DAVIS, GA BURCHFIEL, BC TI ISOTOPIC COMPLEXITIES AND THE AGE OF THE DELFONTE VOLCANIC-ROCKS, EASTERN MESCAL RANGE, SOUTHEASTERN CALIFORNIA - STRATIGRAPHIC AND TECTONIC IMPLICATIONS SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID CENTRAL SIERRA-NEVADA; CONTINUOUS LASER; ANTARCTICA AB Combined U-Pb zircon, Rb-Sr, Ar-40/Ar-39 laser-fusion, and conventional K-Ar geochronology establish a late Early Cretaceous age for the Delfonte volcanic rocks. U-Pb zircon analyses define a lower intercept age of 100.5 +/- 2 Ma that is interpreted as the crystallization age of the Delfonte sequence. Argon studies document both xenocrystic contamination and postemplacement Ar loss. Rb-Sr results from mafic lavas at the base of the sequence demonstrate compositionally correlated variations in initial Sr-87/Sr-86 ratios (Sr(i)) from 0.706 for basalts to 0.716 for andesitic compositions. This covariation indicates substantial mixing of subcontinental lithosphere with Proterozoic upper crust. Correlations between Rb/Sr and Sr(i) may result not only in pseudoisochrons approaching the age of the crustal component, but also in reasonable but incorrect apparent ages approaching the true age. Ages obtained in this study require that at least some of the thrust faulting in the Mescal Range-Clark Mountain portion of the foreland fold-and-thrust belt occurred later than ca. 100 Ma and was broadly contemporaneous with emplacement of the Keystone thrust plate in the Spring Mountains to the northeast. Comparison of the age and Rb-Sr systematics of ash-flow tuff boulders in the synorogenic Lavinia Wash sequence near Goodsprings, Nevada, with those of the Delfonte volcanic rocks supports a Delfonte source for the boulders. The 99 Ma age of the Lavinia Wash sequence is nearly identical to the Delfonte age, requiring rapid erosion, transport, and deposition following Delfonte volcanism. C1 UNIV CALIF SANTA BARBARA,DEPT GEOL SCI,SANTA BARBARA,CA 93106. US GEOL SURVEY,NATL CTR,RESTON,VA 22092. MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. UNIV SO CALIF,DEPT GEOL SCI,LOS ANGELES,CA 90089. RP FLECK, RJ (reprint author), US GEOL SURVEY,MS 937,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 39 TC 13 Z9 13 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 OCT PY 1994 VL 106 IS 10 BP 1242 EP 1253 DI 10.1130/0016-7606(1994)106<1242:ICATAO>2.3.CO;2 PG 12 WC Geosciences, Multidisciplinary SC Geology GA PJ579 UT WOS:A1994PJ57900002 ER PT J AU SAWYER, DA FLECK, RJ LANPHERE, MA WARREN, RG BROXTON, DE HUDSON, MR AF SAWYER, DA FLECK, RJ LANPHERE, MA WARREN, RG BROXTON, DE HUDSON, MR TI EPISODIC CALDERA VOLCANISM IN THE MIOCENE SOUTHWESTERN NEVADA VOLCANIC FIELD - REVISED STRATIGRAPHIC FRAMEWORK, AR-40 AR-39 GEOCHRONOLOGY, AND IMPLICATIONS FOR MAGMATISM AND EXTENSION SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID OASIS-VALLEY CALDERA; DETACHMENT FAULT SYSTEM; WESTERN UNITED-STATES; ASH-FLOW SHEETS; TIMBER MOUNTAIN; TERTIARY EXTENSION; SOUTHERN NEVADA; BLACK MOUNTAIN; GREAT-BASIN; EVOLUTION AB The middle Miocene southwestern Nevada volcanic field (SWNVF) is a classic example of a silicic multicaldera volcanic field in the Great Basin. More than six major calderas formed between >15 and 7.5 Ma. The central SWNVF caldera cluster consists of the overlapping Silent Canyon caldera complex, the Claim Canyon caldera, and the Timber Mountain caldera complex, active from 14 to 11.5 Ma and centered on topographic Timber Mountain. Locations of calderas older than the Claim Canyon caldera source of the Tiva Canyon Tuff are uncertain except where verified by drilling. Younger peralkaline calderas (Black Mountain and Stonewall Mountain) formed northwest of the central SWNVF caldera cluster. We summarize major revisions of the SWNVF stratigraphy that provide for correlation of lava flows and small-volume tuffs with the widespread outflow sheets of the SWNVF. New laser fusion Ar-40/Ar-39 isotopic ages are used to refine and revise the timing of eruptive activity in the SWNVF. The use of high-sensitivity mass spectrometry allowed analysis of submilligram-sized samples with analytical uncertainties of approximately 0.3% (1 sigma), permitting resolution of age differences as small as 0.07 Ma. These results confirm the revised stratigraphic succession and document a pattern of episodic volcanism in the SWNVF. Major caldera episodes (Belted Range, Crater Flat, Paintbrush, Timber Mountain, and Thirsty Canyon Groups) erupted widespread ash-flow sheets within 100-300 k.y. time spans, and pre- and post-caldera lavas erupted within 100-300 k.y. of the associated ash flows. Peak volcanism in the SWNVF occurred during eruption of the Paintbrush and Timber Mountain Groups, when over 4500 km3 of metaluminous magma was erupted in two episodes within 1.35 m.y., separated by a 750 k.y. magmatic gap. Peralkaline and metaluminous magmatism in the SWNVF overlapped in time and space. The peralkaline Tub Spring and Grouse Canyon Tuffs erupted early, and the peralkaline Thirsty Canyon Group tuffs and Stonewall Flat Tuff erupted late in the history of the SWNVF, flanking the central, volumetrically dominant peak of metaluminous volcanism. Magma chemistry transitional between peralkaline and metaluminous magmas is indicated by petrographic and chemical data, particularly in the overlapping Grouse Canyon and Area 20 calderas of the Silent Canyon caldera complex. Volcanism in the SWNVF coincided with the Miocene peak of extensional deformation in adjoining parts of the Great Basin. Although regional extension was concurrent with volcanism, it was at a minimum in the central area of the SWNVF, where synvolcanic faulting was dominated by intracaldera deformation. Significant stratal tilting and paleomagnetically determined dextral shear affected the southwestern margin of the SWNVF between the Paintbrush and Timber Mountain caldera episodes. Larger magnitude detachment faulting in the Bullfrog Hills, southwest of the central SWNVF caldera cluster, followed the climatic Timber Mountain caldera episode. Postvolcanic normal faulting was substantial to the north, east, and south of the central SWNVF caldera cluster, but the central area of peak volcanic activity remained relatively unextended in postvolcanic time. Volcanism and extension in the SWNVF area were broadly concurrent, but in detail they were episodic in time and not coincident in space. C1 US GEOL SURVEY,MENLO PK,CA 94025. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP SAWYER, DA (reprint author), US GEOL SURVEY,MS 913,DENVER,CO 80225, USA. NR 81 TC 118 Z9 119 U1 1 U2 8 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 OCT PY 1994 VL 106 IS 10 BP 1304 EP 1318 DI 10.1130/0016-7606(1994)106<1304:ECVITM>2.3.CO;2 PG 15 WC Geosciences, Multidisciplinary SC Geology GA PJ579 UT WOS:A1994PJ57900007 ER PT J AU PIERSON, TC JANDA, RJ AF PIERSON, TC JANDA, RJ TI VOLCANIC MIXED AVALANCHES - A DISTINCT ERUPTION-TRIGGERED MASS-FLOW PROCESS AT SNOW-CLAD VOLCANOS SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID MOUNT-ST-HELENS; LAHARS AB A generally unrecognized type of pyroclastic deposit was produced by rapid avalanches of intimately mixed snow and hot pyroclastic debris during eruptions at Mount St. Helens, Nevado del Ruiz, and Redoubt Volcano between 1982 and 1989. These ''mixed avalanches'' traveled as far as 14 km at velocities up to approximately 27 m/s, involved as much as 10(7) m3 of rock and ice, and left unmelted deposits of single flow units as thick as 5 m. During flow downslope, heat transfer from hot rocks to snow produced meltwater that partially saturated the mixtures, apparently giving these mixed avalanches mobilities equal to or greater than those of ''dry'' debris avalanches of similar volume. The avalanches studied for this report began as snow avalanches, triggered during explosive phases of the eruptions by ballistic bombardment of snow slopes by hot pyroclastic debris. Erosion by the avalanches incorporated additional snow, fragments of glacier ice, and other rock debris. Mixed-avalanche deposits were massive, very poorly sorted, and ungraded to inversely graded prior to melting. Although rock debris composed as much as 70 wt% of the frozen samples, the bulk volumetric content of rock debris was only 9% to 36%. Snow and ice composed between 36% and 72% of the frozen samples, with void space making up the remainder of the volume. Deformation and consolidation after melting of the ice content reduced the deposits to loose, porous layers that were only a fraction of their original thickness and that later gave little hint of their origin. After melting and desiccation, the deposits are highly susceptible to erosion and unlikely to be well preserved in the stratigraphic record. RP PIERSON, TC (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661, USA. NR 31 TC 26 Z9 26 U1 0 U2 1 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 OCT PY 1994 VL 106 IS 10 BP 1351 EP 1358 DI 10.1130/0016-7606(1994)106<1351:VMAADE>2.3.CO;2 PG 8 WC Geosciences, Multidisciplinary SC Geology GA PJ579 UT WOS:A1994PJ57900010 ER PT J AU LOWENSTERN, JB AF LOWENSTERN, JB TI DISSOLVED VOLATILE CONCENTRATIONS IN AN ORE-FORMING MAGMA SO GEOLOGY LA English DT Article ID EVOLUTION; COLORADO; FLUIDS AB Infrared spectroscopic measurements of glass inclusions within quartz phenocrysts from the Plinian fallout of the 22 Ma tuff of Pine Grove (southwestern Utah) show that the trapped silicate melt contained high concentrations of H2O (6-8 wt%) and CO2 (60-960 ppm). Inclusion compositions are consistent with either open- or closed-system degassing of this high-silica rhyolite during ascent from 16 km (430 MPa) to 9 km (250 MPa) depth, prior to eruption. Intrusive porphyries from the Pine Grove system are nearly identical in age, composition, and mineralogy to the tephra, and some contain high-grade Mo mineralization. Assuming that the porphyry magmas originally contained similar abundances of volatile components as the erupted rocks, they would have been saturated with fluid at pressures far greater than those at which the porphyries were emplaced and mineralized. Even if no initial exsolved fluid was present when the magma began to ascend, it would have contained 19 to 39 vol% bubbles at the approximately 3 km depth (80 MPa) of emplacement of many porphyries. The decrease in magma density and increase in porosity would have facilitated magma convection as well as advection of magmatic aqueous fluid through an interconnected network of bubbles. The data are consistent with formation of Climax-type Mo porphyry deposits by prolonged fluid flux from a large volume (> 20 km3) of relatively Mo-poor (1-5 ppm) magma. RP LOWENSTERN, JB (reprint author), US GEOL SURVEY,MS 910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. OI Lowenstern, Jacob/0000-0003-0464-7779 NR 19 TC 92 Z9 105 U1 6 U2 24 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD OCT PY 1994 VL 22 IS 10 BP 893 EP 896 DI 10.1130/0091-7613(1994)022<0893:DVCIAO>2.3.CO;2 PG 4 WC Geology SC Geology GA PJ581 UT WOS:A1994PJ58100007 ER PT J AU INGEBRITSEN, SE HAYBA, DO AF INGEBRITSEN, SE HAYBA, DO TI FLUID-FLOW AND HEAT-TRANSPORT NEAR THE CRITICAL-POINT OF H2O SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOTHERMAL RESERVOIR SIMULATION; DOMINATED HYDROTHERMAL SYSTEMS; THERMAL-CONDUCTIVITY; ZONES AB Near-critical extrema in the properties of water may influence flow patterns in hydrothermal systems, but singularities in equations of state for H2O at its critical point have inhibited quantitative modeling. Posing governing equations in terms of pressure (P) and enthalpy (H) avoids these singularities and facilitates computation. Numerical simulations with a P-H based model show little near-critical enhancement in heat transfer for systems in which flow is driven by fixed pressure drops. However, in density-driven systems, near-critical variations in fluid properties can enhance convective heat transfer by a factor of 10(2) or more (''superconvection'') if permeability is sufficiently high. Near-critical two-phase processes (''heat pipes'') are at feast equally effective at dissipating thermal energy. The restriction to high-permeability environments within a fairly narrow P-H window suggests that superconvection may be quite rare in natural systems C1 US GEOL SURVEY,RESTON,VA 22092. RP INGEBRITSEN, SE (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 18 TC 24 Z9 24 U1 1 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 1994 VL 21 IS 20 BP 2199 EP 2202 DI 10.1029/94GL02002 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PK063 UT WOS:A1994PK06300005 ER PT J AU IKEHARA, ME AF IKEHARA, ME TI GLOBAL POSITIONING SYSTEM SURVEYING TO MONITOR LAND SUBSIDENCE IN SACRAMENTO VALLEY, CALIFORNIA, USA SO HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES LA English DT Article AB A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2, using Global Positioning System (GPS) surveying. A brief description of GPS surveying is followed by a summary of each of four surveys between 1985 and 1989. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. RP IKEHARA, ME (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,2800 COTTAGE WAY,RM W-2233,SACRAMENTO,CA 95825, USA. NR 0 TC 12 Z9 12 U1 0 U2 2 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 OCT PY 1994 VL 39 IS 5 BP 417 EP 429 DI 10.1080/02626669409492765 PG 13 WC Water Resources SC Water Resources GA PK960 UT WOS:A1994PK96000001 ER PT J AU SAVAGE, WZ AF SAVAGE, WZ TI GRAVITY-INDUCED STRESSES IN FINITE SLOPES SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article ID LONG SYMMETRIC RIDGES; ELASTIC SLOPES; VALLEYS AB An exact solution for gravity-induced stresses in finite elastic slopes is presented. This solution, which is applied for gravity-induced stresses in 15, 30, 45 and 90 degrees finite slopes, has application in pit-slope design, compares favorably with published finite element results for this problem and satisfies the conditions that shear and normal stresses vanish on the ground surface. The solution predicts that horizontal stresses nr e compressive along the top of the slopes (zero in the case of the 90 degrees slope) and tensile away from the bottom of the slopes, effects which are caused by downward movement and near-surface horizontal extension in front of the slope in response to gravity loading caused by the additional material associated with the finite slope. RP SAVAGE, WZ (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 966,DENVER,CO 80225, USA. NR 14 TC 16 Z9 16 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD OCT PY 1994 VL 31 IS 5 BP 471 EP 483 DI 10.1016/0148-9062(94)90150-3 PG 13 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA PJ357 UT WOS:A1994PJ35700007 ER PT J AU HOBSON, KA PIATT, JF PITOCCHELLI, J AF HOBSON, KA PIATT, JF PITOCCHELLI, J TI USING STABLE ISOTOPES TO DETERMINE SEABIRD TROPHIC RELATIONSHIPS SO JOURNAL OF ANIMAL ECOLOGY LA English DT Article DE C-13; N-15; SEABIRD COMMUNITY; STABLE-ISOTOPE ANALYSIS; TROPHIC LEVELS ID FOOD-WEB STRUCTURE; MARBLED MURRELETS; BONE-COLLAGEN; DELTA-C-13 ANALYSIS; BRITISH-COLUMBIA; CARBON ISOTOPES; MARINE; DIET; TISSUES; FISH AB 1. The stable isotopes of nitrogen (deltaN-15) and carbon (deltaC-13) were analysed in 22 species of marine birds from coastal waters of the northeast Pacific Ocean. Analyses confirm that stable nitrogen isotopes can predict seabird trophic positions. 2. Based on deltaN-15 analyses, seabird trophic-level inferences generally agree with those of conventional dietary studies, but suggest that lower trophic-level organisms are more important to several seabirds than was recognized previously. 3. Stable-carbon isotope analysis may be a good indicator of inshore vs. offshore feeding preference. 4. In general, stable-isotope analysis to determine trophic level offers many advantages over conventional dietary approaches since trophic inferences are based on time-integrated estimates of assimilated and not just ingested foods, and isotopic abundance represents a continuous variable that is amenable to statistical analysis. C1 UNIV SASKATCHEWAN,DEPT BIOL,SASKATOON S7N 0W0,SASKATCHEWAN,CANADA. US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. ST ANSELM COLL,DEPT BIOL,MANCHESTER,NH 03102. NR 73 TC 420 Z9 443 U1 16 U2 98 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0021-8790 J9 J ANIM ECOL JI J. Anim. Ecol. PD OCT PY 1994 VL 63 IS 4 BP 786 EP 798 DI 10.2307/5256 PG 13 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA PM016 UT WOS:A1994PM01600005 ER PT J AU HANCHAR, JM MILLER, CF WOODEN, JL BENNETT, VC STAUDE, JMG AF HANCHAR, JM MILLER, CF WOODEN, JL BENNETT, VC STAUDE, JMG TI EVIDENCE FROM XENOLITHS FOR A DYNAMIC LOWER CRUST, EASTERN MOJAVE DESERT, CALIFORNIA SO JOURNAL OF PETROLOGY LA English DT Review ID WOMAN MOUNTAINS AREA; LOWER CONTINENTAL-CRUST; SOUTHEASTERN CALIFORNIA; CENTRAL ARIZONA; SIERRA-NEVADA; GARNET AMPHIBOLITES; GRANULITE TERRANES; COLORADO PLATEAU; NORTHERN MEXICO; WESTERN ARIZONA AB Garnet-rich xenoliths in a Tertiary dike in the eastern Mojave Desert, California, preserve information about the nature and history of the lower crust. These xenoliths record pressures of similar to 10-12 kbar and temperatures of similar to 750-800 degrees C. Approximately 25% have mafic compositions and bear hornblende+plagioclase+clinopyroxene+quartz in addition to garnet. The remainder, all of which contain quartz, include quartzose, quartzofeldspathic, and aluminous (kyanite+/-sillimanite-bearing) varieties. Most xenoliths have identifiable protoliths-mafic from intermediate or mafic igneous rocks, quartzose from quartz-rich sedimentary rocks, aluminous from Al-rich graywackes or pelites, and quartzofeldspathic from feldspathic sediments and/or intermediate to felsic igneous rocks. However, many have unusual chemical compositions characterized by high FeO(t), FeO(t)/MgO, Al2O3, and Al2O3/CaO, which correspond to high garnet abundance. The mineralogy and major- and trace-element compositions are consistent with the interpretation that the xenoliths are the garnet-rich residues of high-pressure crustal melting, from which granitic melt was extracted. High Sr-87/Sr-86 and low Nd-143/Nd-144, together with highly discordant zircons from a single sample with Pb/Pb ages of similar to 1.7 Ga, demonstrate that the crustal material represented by the xenoliths is at least as old as Early Proterozoic. This supracrustal-bearing lithologic assemblage may have been emplaced in the lower crust during either Proterozoic or Mesozoic orogenesis, but Sr and Nd model ages >4 Ga require late Phanerozoic modification of parent/daughter ratios, presumably during the anatectic event. Pressures of equilibration indicate that peak metamorphism and melting occurred before the Mojave crust had thinned to its current thickness of <30 km. The compositions of the xenoliths suggest that the lower crust here is grossly similar to estimated world-wide lower-crustal compositions in terms of silica and mafic content; however, it is considerably more peraluminous, has a lower mg-number, and is distinctive in some trace element concentrations, reflecting its strong metasedimentary and restitic heritage. C1 US GEOL SURVEY,MENLO PK,CA 94025. AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 2601,AUSTRALIA. UNIV ARIZONA,DEPT GEOSCI,TUCSON,AZ 85721. RP HANCHAR, JM (reprint author), VANDERBILT UNIV,DEPT GEOL,221 KIRKLAND HALL,NASHVILLE,TN 37235, USA. NR 122 TC 25 Z9 26 U1 0 U2 5 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD OCT PY 1994 VL 35 IS 5 BP 1377 EP 1415 PG 39 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PT362 UT WOS:A1994PT36200007 ER PT J AU SAFAK, E FRANKEL, A AF SAFAK, E FRANKEL, A TI STRUCTURAL RESPONSE TO 3D SIMULATED EARTHQUAKE MOTIONS IN SAN-BERNARDINO-VALLEY SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article ID CALIFORNIA AB Structural response to one- and three-dimensional (3D) simulated motions in San Bernardino Valley, Calif., from a hypothetical earthquake along the San Andreas Fault with moment magnitude 6.5 and rupture length of 30 km (18.6 mi) is investigated. For three stations that are close to each other and to the fault line, various measures of ground motions (e.g., peak values, intensities, durations, and effective frequency bands), elastic and elastoplastic response spectra, and the response of a 10-story, three-bay frame are calculated. Because the simulation results are reliable up to 1 Hz, only long-period structures, with periods of 1 to 10 sec, are considered. The results show that the ground motions and the structural response vary dramatically with the type of simulation and the location. In general, one-dimensional (1D) simulations underestimated the response and resulted in values as low as one-fifth of those of 3D simulations. The difference in the structural response at three stations was found to be as high as a factor of six. The reasons for such large differences are the trapping of seismic waves in the basin and the constructive interference of surface waves traveling in different directions, none of which can be accounted for by 1D models, and the strong influence of source directivity. C1 US GEOL SURVEY,DENVER,CO 80225. RP SAFAK, E (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 14 TC 0 Z9 1 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD OCT PY 1994 VL 120 IS 10 BP 2820 EP 2839 PG 20 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA PH603 UT WOS:A1994PH60300002 ER PT J AU ROCKE, TE BRAND, CJ AF ROCKE, TE BRAND, CJ TI USE OF SENTINEL MALLARDS FOR EPIZOOTIOLOGIC STUDIES OF AVIAN BOTULISM SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE AVIAN BOTULISM; CLOSTRIDIUM BOTULINUM TYPE C; SENTINELS; MALLARDS; ANAS PLATYRHYNCHOS; MORTALITY RATES ID SURVIVAL; TELEMETRY AB Captive-reared mallards (Anas platyrhynchos) were used as sentinels to study the epizootiology of avian botulism at the Sacramento National Wildlife Refuge, Willows, California (USA) from 1986 to 1989. Sentinel mallards were wing-clipped, and 40 to 50 birds were confined in 1.6-ha enclosures in 11 selected wetlands (pools). Enclosures were searched intensively three to four times weekly from July through October, Sick and dead wild and sentinel birds were collected, necropsied, and tested for type C botulism toxin. Botulism epizootics occurred in sentinel mallards in 1986, 1987, and 1989, but only a few isolated cases of botulism were detected in 1988. In most epizootics, botulism also was detected simultaneously in wild birds using the same pool outside the enclosure. Epizootics in sentinels were initiated and perpetuated in the absence of vertebrate carcasses. A sex-specific trend in the probability of intoxication was detected, with males contracting botulism at a higher rate than females. Daily mortality rates of sentinels during botulism epizootics ranged from 0.0006 to 0.0600, with a mean of 0.0190. These rates would result in the daily loss of 0.6 to 60 birds per thousand at risk. The use of sentinel birds provided an effective means of gathering site-specific epizootiologic data. RP ROCKE, TE (reprint author), US FISH & WILDLIFE SERV,NATL WILDLIFE HLTH RES CTR,6006 SCHROEDER RD,MADISON,WI 53711, USA. OI Rocke, Tonie/0000-0003-3933-1563 NR 19 TC 8 Z9 8 U1 0 U2 4 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 1994 VL 30 IS 4 BP 514 EP 522 PG 9 WC Veterinary Sciences SC Veterinary Sciences GA PR495 UT WOS:A1994PR49500006 PM 7760480 ER PT J AU MONDA, MJ RATTI, JT MCCABE, TR AF MONDA, MJ RATTI, JT MCCABE, TR TI REPRODUCTIVE ECOLOGY OF TUNDRA SWANS ON THE ARCTIC-NATIONAL-WILDLIFE-REFUGE, ALASKA SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE ALASKA; ARCTIC; BEHAVIOR; BROOD; CYGNUS-COLUMBIANUS; FORAGING; GRAZING; HABITAT; NEST; TUNDRA SWAN; WATERFOWL ID CANADA GEESE; PLANTS; CAREX; LEAF; PRODUCTIVITY; AVAILABILITY; DEMOGRAPHY; NUTRITION; RESPONSES; SURVIVAL AB Management of tundra swans (Cygnus columbianus) is hampered by a lack of information on their nesting and brood-rearing ecology. We studied tundra swan nesting and brood-rearing ecology on the Arctic National Wildlife Refuge (ANWR), Alaska, 1988-90. Nest success was 58% (n = 31) in 1988, 83% (n = 36) in 1989, 84% (n = 43) in 1990, and 76% (n = 110) for the 3 years. Nests were located predominately in marshes dominated by sheathed pondweed (Potamogeton vaginatus), mare's tail (Hippuris vulgaris), and Hoppner sedge (Carex subspathacea), or by pendent grass (Arctophila fulva), water sedge (C. aquatilis), and tall cotton grass (Eriophorum angustifolium). Nests were seldom located in upland or partially vegetated habitats and were near coastal lagoons or large coastal lakes. Incubating swans were easily disturbed by ground observers and left their nests when we were 500-2,000 m from the nest. Swans did not cover eggs with nest material prior to departure; thus, eggs were vulnerable to avian predation and thermal stress. Brood-foraging sites on the Kongakut Delta (n = 41) were frequently in aquatic-marsh (59%) and saline graminoid-shrub (29%) habitats, occasionally in graminoid-marsh (7%) and partially vegetated (5%) habitats, and absent from upland, graminoid-shrub-water sedge, and graminoid-shrub-cotton grass habitats. Brood-foraging sites on the Canning Delta (n = 35) were frequently in graminoid-marsh (46%), graminoid-shrub-water sedge (26%), and aquatic-marsh (23%) habitats, occasionally in graminoid-shrub-cotton grass (3%) and upland habitats (3%), and absent from saline graminoid-shrub and partially vegetated habitats. Young cygnets grazed in terrestrial habitats more frequently than older broods on the Kongakut (P = 0.003) and Canning (P = 0.053) deltas. Wetlands with sheathed pondweed were uncommon but preferred by broods (P = 0.001). Using field experiments, we evaluated effects of swan grazing and fertilization from feces on aboveground biomass production and plant-species composition. Fertilization from swan feces did not have an overall effect (P = 0.991) or interact with clipping (simulated grazing with hand shears) (P = 0.881) for any response variable investigated. Clipping increased total vegetational biomass the year of clipping (P = 0.001), decreased biomass the year after clipping (P = 0.001), and increased total shoot densities (P = 0.017). Shoot densities after clipping increased for Hoppner sedge (P = 0.010), did not change for tundra grass (Dupontia fischeri) (P = 0.296), and decreased for chickweed (Stellaria humifusa) (P = 0.006). Traditional use of foraging sites may enhance grazing areas by increasing plant production the year of grazing and densities of plant species that tolerate grazing. Protection of aquatic-marsh, graminoid-marsh, and saline graminoid-shrub habitats, particularly those supporting sheathed pondweed and traditionally used nesting areas, is important for maintaining current swan populations on ANWR. C1 UNIV IDAHO,DEPT FISH & WILDLIFE RESOURCES,MOSCOW,ID 83843. US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,FAIRBANKS,AK 99701. NR 61 TC 10 Z9 11 U1 4 U2 13 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 1994 VL 58 IS 4 BP 757 EP 773 DI 10.2307/3809691 PG 17 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA PL727 UT WOS:A1994PL72700021 ER PT J AU DUBOVSKY, JA KAMINSKI, RM AF DUBOVSKY, JA KAMINSKI, RM TI POTENTIAL REPRODUCTIVE CONSEQUENCES OF WINTER-DIET RESTRICTION IN MALLARDS SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE ANAS-PLATYRHYNCHOS; FOOD AVAILABILITY; MALLARD; MISSISSIPPI; REPRODUCTION; WETLAND; WINTER ID FEMALE MALLARDS; BODY; RECRUITMENT; SURVIVAL; BROODS; BIRDS; DUCK; FAT AB Food restriction during winter may subsequently affect waterfowl reproduction. Therefore, we tested the effects of restricted and ad libitum (control) food availability during winter 1987-88 on reproductive performance of captive wild-strain and game-farm female mallards (Anas platyrhynchos) in Mississippi. Females fed restricted diets weighed less (P < 0.01) at the end of winter but regained mass within 1-2 weeks following ad libitum feeding. Game-farm mallards on restricted diets initiated nesting 3 weeks later (P < 0.001) than did control females. Wild-strain mallards nested 1 week later than did controls, but no difference (P = 0.11) was detected (likely due to small sample size). Means for body mass at nest initiation and other reproductive variables (e.g., clutch size, egg mass) generally did not differ (P > 0.05) between females fed restricted diets and those fed ad libitum. Few wild-strain females renested, but clutch sizes of game-farm females declined (P < 0.01) after initial nests. Simulation modeling revealed that recruitment rates (i.e., n F/breeding F) may decrease 3-15% if free-ranging mallards were to experience nesting delays of 1-3 weeks. We hypothesize that poor feeding conditions during winter could negatively affect mallard recruitment primarily through delayed nesting, but replication of our study with wild-strain ducks and other experimental design considerations is recommended. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,11500 AMER HOLLY DR,LAUREL,MD 20708. RP DUBOVSKY, JA (reprint author), MISSISSIPPI STATE UNIV,DEPT WILDLIFE & FISHERIES,MISSISSIPPI STATE,MS 39762, USA. NR 34 TC 21 Z9 21 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 1994 VL 58 IS 4 BP 780 EP 786 DI 10.2307/3809693 PG 7 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA PL727 UT WOS:A1994PL72700023 ER PT J AU PATRICK, B TILL, AB DINKLAGE, WS AF PATRICK, B TILL, AB DINKLAGE, WS TI AN INVERTED METAMORPHIC FIELD GRADIENT IN THE CENTRAL BROOKS RANGE, ALASKA AND IMPLICATIONS FOR EXHUMATION OF HIGH-PRESSURE LOW-TEMPERATURE METAMORPHIC ROCKS SO LITHOS LA English DT Article ID PENINSULA BLUESCHIST TERRANE; SEWARD PENINSULA; STRUCTURAL EVOLUTION; THRUST BELT; MINERALIZATION; CORDILLERA; OROGEN; FOLD; MG; FE AB During exhumation of the Brooks Range internal zone, amphibolite-facies rocks were emplaced atop the blueschist/greenschist facies schist belt. The resultant inverted metamorphic field gradient is mappable as a series of isograds encountered as one traverses up structural section. Amphibolite-facies metamorphism occurred at approximately 110 Ma as determined from Ar-40/Ar-39 analysis of hornblende. This contrasts with Ar-40/Ar-39 phengite cooling ages from the underlying schist belt, which are clearly older (by 17-22 m.y.). Fabrics in both the amphibolite-facies rocks and schist belt are characterized by repeated cycles of N-vergent crenulation and transposition that was likely associated with out-of-sequence ductile thrusting in the internal zone of the Brooks Range orogen. Contractional deformation occurred in an overall environment of foreland-directed tectonic transport, broadly synchronous with exhumation of the internal zone, and shortening within the thin-skinned fold and thrust belt. These data are inconsistent with a recently postulated mid-Cretaceous episode of lithospheric extension in northern Alaska. C1 US GEOL SURVEY,ANCHORAGE,AK 99508. RP PATRICK, B (reprint author), UNIV CALIF SANTA BARBARA,DEPT GEOL SCI,SANTA BARBARA,CA 93106, USA. NR 56 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0024-4937 J9 LITHOS JI Lithos PD OCT PY 1994 VL 33 IS 1-3 BP 67 EP 83 DI 10.1016/0024-4937(94)90054-X PG 17 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PR137 UT WOS:A1994PR13700005 ER PT J AU SCHIFFMAN, R DEAN, A CHANEY, RC SUCHANEK, J VEGA, B MCFARLAND, T SCHULTHEISS, PJ GUNN, D KELLER, GH NOORANY, I FAGHIHI, M SHEPHARD, L LIPKIN, J KINKER, J BRYANT, WR TAYLOR, E JOHNS, M SILVA, AJ LEVY, WP SICILIANO, R DADEY, K OLSEN, H AF SCHIFFMAN, R DEAN, A CHANEY, RC SUCHANEK, J VEGA, B MCFARLAND, T SCHULTHEISS, PJ GUNN, D KELLER, GH NOORANY, I FAGHIHI, M SHEPHARD, L LIPKIN, J KINKER, J BRYANT, WR TAYLOR, E JOHNS, M SILVA, AJ LEVY, WP SICILIANO, R DADEY, K OLSEN, H TI GEOTECHNICAL PROPERTIES OF NORTHWEST PACIFIC PELAGIC CLAYS - DEEP-SEA DRILLING PROJECT LEG-86, HOLE-576A (REPRINTED FROM INITIAL REPORTS OF THE DEEP SEA DRILLING PROJECT, VOL 86, 1985) SO MARINE GEORESOURCES & GEOTECHNOLOGY LA English DT Reprint AB Geotechnical property results from Deep Sea Drilling Project Hole 576A sediments represent the most complete data set ever compiled for a continuously depositional! sedimentary section that spans 65 m.y. Geotechnical analyses included index-property and sediment characterization, and consolidation, permeability, and triaxial testing. Excellent agreement exists between test data generated in this multilaboratory effort. Sediment characterization and index-property data delineate three well-defined units that conform with major lithologic divisions. Within Subunit IA these data appear inconsistent with accepted geotechnical relationships, showing water content, plasticity, and grain size increasing over similar intervals. These unusual relationships are attributed in part, to silt-sized bonded clay aggregates. Within Subunit IB geotechnical properties become more uniform, and a marked increase in X-ray amorphous material occurs below 28 m sub-bottom. A pronounced change in the geotechnical behavior of Hole 576A sediments occurs in Unit II and corresponds to the presence of calcareous oozes. Consolidation test results show overconsolidated sediments in the upper 28 m and normally consolidated sediments between 28 and 55 m sub-bottom. Mechanisms to explain the state of overconsolidation that are consistent with the geological history of the area include cementation and interparticle bonding, the release of high hydrostatic pressures during core recovery, and artifacts resulting from the consolidation test process. Additionally, the relevance of the preconsolidation stress determined using consolidation test results may be limited. C1 HUMBOLT STATE UNIV,ARCATA,CA. INST OCEANOG SCI,GODALMING GU8 5UB,SURREY,ENGLAND. OREGON STATE UNIV,CORVALLIS,OR. SAN DIEGO UNIV,SAN DIEGO,CA. SANDIA NATL LAB,ALBUQUERQUE,NM. TEXAS A&M UNIV,COLLEGE STN,TX. UNIV RHODE ISL,NARRAGANSETT,RI. US GEOL SURVEY,DENVER,CO. RP SCHIFFMAN, R (reprint author), UNIV COLORADO,BOULDER,CO 80302, USA. NR 38 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1064-119X J9 MAR GEORESOUR GEOTEC JI Mar. Geores. Geotechnol. PD OCT-DEC PY 1994 VL 12 IS 4 BP 341 EP 404 PG 64 WC Engineering, Ocean; Engineering, Geological; Oceanography; Mining & Mineral Processing SC Engineering; Oceanography; Mining & Mineral Processing GA RE453 UT WOS:A1994RE45300004 ER PT J AU MAYER, H AF MAYER, H TI CYCLOSTRATIGRAPHIC CALIBRATION OF CRETACEOUS MAGNETIC POLARITY EVENTS (CISMON, SOUTHERN ALPS, ITALY SO MATHEMATICAL GEOLOGY LA English DT Article; Proceedings Paper CT Quantitative Stratigraphy Session at the Silver Anniversary Meeting of the International-Association-for-Mathematical-Geology CY OCT, 1993 CL PRAGUE, CZECH REPUBLIC SP INT ASSOC MATH GEOL DE GEOLOGIC TIME SCALE; MAGNETOSTRATIGRAPHY; MILANKOVITCH CYCLES; TIME-SERIES ANALYSIS; VALANGINIAN; HAUTERIVIAN; MAIOLICA; BIANCONE FORMATION ID TIME SCALE; SEDIMENTATION; STRATIGRAPHY; MIDDLE; CYCLES AB In an introductory section the problems of constructing a geologic time scale and the role of magnetic reversals and Milankovitch cycles in geochronology are outlined. Results of a detailed cyclostratigraphic and magnetostratigraphic study of the Valanginian/Hauterivian part of the pelagic limestone section at Cismon in the Southern Alps are presented and used in conjunction to estimate the duration of magnetic subchrons between CM10N and CM8. The new estimates are shorter than in most published time scales by a factor of two to three. More research along these lines may make a revision of the Early Cretaceous time scale necessary. C1 US GEOL SURVEY,DENVER,CO 80225. RP MAYER, H (reprint author), UNIV TUBINGEN,INST GEOL & PALAONTOL,W-7400 TUBINGEN 1,GERMANY. NR 39 TC 4 Z9 4 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD OCT PY 1994 VL 26 IS 7 BP 783 EP 798 DI 10.1007/BF02083117 PG 16 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA PY283 UT WOS:A1994PY28300004 ER PT J AU LANDA, ER STIEFF, LR GERMANI, MS TANNER, AB EVANS, JR AF LANDA, ER STIEFF, LR GERMANI, MS TANNER, AB EVANS, JR TI INTENSE ALPHA-PARTICLE EMITTING CRYSTALLITES IN URANIUM MILL WASTES SO NUCLEAR GEOPHYSICS LA English DT Article AB Nuclear emulsion microscopy has demonstrated the presence of small, intense alpha-particle emitting crystallites in laboratory-produced tailings derived from the sulfuric acid milling of uranium ores. The alpha-particle activity is associated with the isotope pair Pb-210/Pb-210Po, and the host mineral appears to be PbSO4 occurring as inclusions in gypsum laths. These particles represent potential inhalation hazards at uranium mill tailings disposal areas. RP LANDA, ER (reprint author), US GEOL SURVEY,430 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 8 Z9 8 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8086 J9 NUCL GEOPHYS JI Nucl. Geophys. PD OCT PY 1994 VL 8 IS 5 BP 443 EP 454 PG 12 WC Geochemistry & Geophysics; Nuclear Science & Technology; Mining & Mineral Processing SC Geochemistry & Geophysics; Nuclear Science & Technology; Mining & Mineral Processing GA PM884 UT WOS:A1994PM88400003 ER PT J AU BROWN, DR SHRABLE, JB AF BROWN, DR SHRABLE, JB TI SURVIVAL OF ARCTIC GRAYLING EGGS WATER-HARDENED IN VARIOUS CONCENTRATIONS OF IODOPHOR SO PROGRESSIVE FISH-CULTURIST LA English DT Note ID FALL CHINOOK SALMON; RAINBOW-TROUT; 2 IODOPHORS; TOXICITY AB Survival of eggs of Arctic grayling (Thymallus arcticus) following water hardening in various concentrations of an iodophor, povidone-iodine, solution was investigated. The treatment is effective in reducing the external bacterial load at the surface of the egg and is thought to reduce the risk of vertical transmission of pathogens from parent to offspring. However, in some cases, the use of iodophor during water hardening of salmon and trout eggs has resulted in significant egg losses. Treatment duration and concentrations similar to those commonly used during water hardening of eggs of other salmonid species were tested with Arctic grayling eggs. Water hardening in 50, 75, and 100 mg active iodine per liter resulted in significantly greater egg losses at eye-up than occurred when eggs were hardened in lake water. Mortality was highest in treatments with the strongest iodine concentrations. RP BROWN, DR (reprint author), US FISH & WILDLIFE SERV,ENNIS NATL FISH HATCHERY,180 FISH HATCHERY RD,ENNIS,MT 59729, USA. NR 8 TC 4 Z9 4 U1 0 U2 0 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 1994 VL 56 IS 4 BP 262 EP 264 DI 10.1577/1548-8640(1994)056<0262:SOAGEW>2.3.CO;2 PG 3 WC Fisheries SC Fisheries GA PM186 UT WOS:A1994PM18600008 ER PT J AU KING, CY MINISSALE, A AF KING, CY MINISSALE, A TI SEASONAL VARIABILITY OF SOIL-GAS RADON CONCENTRATION IN CENTRAL CALIFORNIA SO RADIATION MEASUREMENTS LA English DT Article ID PENNSYLVANIA; EXHALATION; TRANSPORT AB Radon concentrations in soil gas were measured by the track-etch method in 60 shallow holes, each 70 cm deep and supported by a capped plastic tube, along several major faults in central California during 1975-1985. This set of data was analyzed to investigate the seasonal variability of soil-gas radon concentration in an area which has various geological conditions but similar climate. The results show several different patterns of seasonal variations, but all of which can be largely attributed to the water-saturation and moisture-retention characteristics of the shallow part of the soil. During the rainy winter and spring seasons, radon tended to be confined underground by the water-saturated surface soil which had much reduced gas permeability, while during the sunny summer and autumn seasons, it exhaled more readily as the soil became drier and more permeable. At several sites located on creeping faults, the radon-variation patterns changed with time, possibly because of disturbance of site condition by fault movement. C1 CNR,CTR STUDIO MINERAL & GEOCHEM SEDIMENTI,I-50121 FLORENCE,ITALY. RP KING, CY (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 45 TC 23 Z9 23 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD OCT PY 1994 VL 23 IS 4 BP 683 EP 692 DI 10.1016/1350-4487(94)90004-3 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PX251 UT WOS:A1994PX25100004 ER PT J AU WILLARD, DA AF WILLARD, DA TI PALYNOLOGICAL RECORD FROM THE NORTH-ATLANTIC REGION AT 3-MA - VEGETATIONAL DISTRIBUTION DURING A PERIOD OF GLOBAL WARMTH SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Review ID POLLEN DISTRIBUTION; COASTAL-PLAIN; PLIOCENE; MARINE; OCEAN; FLORIDA; CLIMATE; HISTORY; TERRESTRIAL; SEDIMENTS AB Pollen assemblages from five mid-Pliocene, deep-marine and shallow-marine sites in the North Atlantic Ocean region were analyzed quantitatively to estimate vegetational composition and terrestrial paleoclimates during a time interval centered at about 3 Ma. Three subarctic sites (58-67 degrees N latitude) from the Norwegian Sea, northern Iceland, and the Labrador Sea yielded pollen assemblages characteristic of mixed conifer-hardwood vegetation; these assemblages have no close modern analogs, but the most similar modern vegetation is that of the Tsuga (hem-lock)-northern hardwood forests of Newfoundland and Nova Scotia (45-50 degrees N). The presence of such vegetation at these sites indicates mid-Pliocene January temperatures from 4 to 10 degrees C warmer than today and a northward shift of the deciduous forest zone into areas presently occupied by boreal forests. Pollen assemblages from the mid-latitude (36 degrees N) Yorktown Formation site in southeastern Virginia, USA represent Quercus-Carya-Pinus (oak-hickory-pine) forests, similar to those presently occupying much of the Atlantic coastal plain of the United States. Modern analogs for this site are located off the coasts of North Carolina and South Carolina, indicating mid-Pliocene January temperatures 3-5 degrees C warmer than today. In southwestern Florida (27 degrees N), pollen assemblages from the mid-Pliocene Pinecrest Beds are representative of pine-dominated communities, similar to Pinus palustris/P. elliottii forests (longleaf/slash pine) growing in Florida today. Close modern analogs for the Pinecrest Beds are located at numerous sites around the Florida peninsula, indicating mid-Pliocene temperatures about the same as today for this region. These sites show a gradient from much higher than present temperatures at high latitudes to little change from present temperatures at low latitudes and low elevations; a similar pattern is shown by mid-Pliocene sea-surface and isotopic data. Such a gradient also is consistent with the northward migration of the boreal forest zone, covering sites as far north as Meighen and Banks Islands, a northward shift of the deciduous-boreal forest boundary in both North America and Europe, and little change in vegetational distribution in low elevation sites in subtropical latitudes during the mid-Pliocene warm interval. Atmospheric temperatures estimated from vegetational distributions indicate a Pliocene to modern temperature anomaly of a similar pattern and magnitude to that indicated by sea-surface temperatures. These data are most consistent with current general circulation model simulations of climate changes in response to increased meridional heat transport. RP WILLARD, DA (reprint author), US GEOL SURVEY,970 NATL CTR,RESTON,VA 22092, USA. NR 102 TC 32 Z9 34 U1 1 U2 9 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 OCT PY 1994 VL 83 IS 4 BP 275 EP 297 DI 10.1016/0034-6667(94)90141-4 PG 23 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA PN943 UT WOS:A1994PN94300001 ER PT J AU LAMBERT, JH MATALAS, NC LING, CW HAIMES, YY LI, D AF LAMBERT, JH MATALAS, NC LING, CW HAIMES, YY LI, D TI SELECTION OF PROBABILITY-DISTRIBUTIONS IN CHARACTERIZING RISK OF EXTREME EVENTS SO RISK ANALYSIS LA English DT Article DE EXTREME EVENTS; PROBABILITY DISTRIBUTIONS; DATA AVAILABILITY; DISTRIBUTION TAIL AB Use of probability distributions by regulatory agencies often focuses on the extreme events and scenarios that correspond to the tail of probability distributions. This paper makes the case that assessment of the tail of the distribution can and often should be performed separately from assessment of the central values. Factors to consider when developing distributions that account for tail behavior include (a) the availability of data, (b) characteristics of the tail of the distribution, and (c) the value of additional information in assessment. The integration of these elements will improve the modeling of extreme events by the tail of distributions, thereby providing policy makers with critical information on the risk of extreme events. Two examples provide insight into the theme of the paper. The first demonstrates the need for a parallel analysis that separates the extreme events from the central values. The second shows a link between the selection of the tail distribution and a decision criterion. In addition, the phenomenon of breaking records in time-series data gives insight to the information that characterizes extreme values. One methodology for treating risk of extreme events explicitly adopts the conditional expected value as a measure of risk. Theoretical results concerning this measure are given to clarify some of the concepts of the risk of extreme events. C1 US GEOL SURVEY,RESTON,VA 22092. RP LAMBERT, JH (reprint author), UNIV VIRGINIA,CTR RISK MANAGEMENT ENGN SYST,CHARLOTTESVILLE,VA 22903, USA. RI Li, Duan/E-7985-2011 NR 30 TC 25 Z9 25 U1 0 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD OCT PY 1994 VL 14 IS 5 BP 731 EP 742 DI 10.1111/j.1539-6924.1994.tb00283.x PG 12 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PT370 UT WOS:A1994PT37000004 ER PT J AU HAGSTRUM, JT LIPMAN, PW MOORE, RB AF HAGSTRUM, JT LIPMAN, PW MOORE, RB TI LATE CRETACEOUS PALEOMAGNETISM OF THE TOMBSTONE DISTRICT AND VICINITY - EVIDENCE FOR A ROTATIONAL DOMAIN BOUNDARY IN SOUTHEASTERN ARIZONA SO TECTONICS LA English DT Article ID APPARENT POLAR WANDER; SOUTH CENTRAL ARIZONA; ASH-FLOW SHEETS; NORTH-AMERICA; COLORADO PLATEAU; NEW-MEXICO; ROCKS; TECTONICS; MOUNTAINS; DEPOSITS AB Paleomagnetic data are presented for Late Cretaceous volcanic and intrusive rocks in the Tombstone district and Dos Cabezas Mountains of southeastern Arizona. The resultant paleopole (73 degrees N, 224 degrees E, A(95) = 8 degrees) is similar to a Late Cretaceous reference pole for North America (82 degrees N, 210 degrees E, A(95) = 7 degrees), implying that these rocks have not been significantly rotated about vertical or near-vertical axes relative to the continental interior. Generally, concordant results have also been published for Pennsylvanian terra rosa paleosols within the Black Prince Limestone at localities in the nearby Gunnison Hills, Whetstone Mountains, and Naco Hills. Together, however, these Carboniferous data indicate a 9 degrees +/- 7 degrees clockwise rotation, with respect to North America, similar to that determined for the Colorado Plateau (5 degrees-14 degrees) since the mid-Cretaceous. Published paleomagnetic data for rocks south and west of the Tombstone vicinity indicate much larger clockwise rotations ranging from similar to 25 degrees to similar to 60 degrees, implying that a rotational domain boundary runs between the Mustang Mountains and Canelo Hills to the southeast and between the Silver Bell and Tucson Mountains to the northwest. This boundary roughly coincides, in part, with the Sawmill Canyon fault zone and is parallel to other northwest trending strike-slip faults in the region that were active during the Laramide orogeny. The clockwise rotations in southern Arizona are likely part of a larger pattern of dextral shear along the western margin of North America during the Late Cretaceous and early Tertiary caused by northward oblique subduction of oceanic plates relative to the stable craton. C1 US GEOL SURVEY,DENVER,CO 80225. RP HAGSTRUM, JT (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 910,MENLO PK,CA 94025, USA. NR 45 TC 5 Z9 5 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 1994 VL 13 IS 5 BP 1295 EP 1308 DI 10.1029/94TC01388 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PK721 UT WOS:A1994PK72100018 ER PT J AU HEFNER, JM STORRS, CG AF HEFNER, JM STORRS, CG TI CLASSIFICATION AND INVENTORY OF WETLANDS IN THE SOUTHERN APPALACHIAN REGION SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT Southern-Appalachian-Man-and-the-Biosphere (SAMAB) Conference on Wetland Ecology, Management, and Conservation CY SEP 28-30, 1993 CL KNOXVILLE, TN SP SO APPALACHIAN MAN & BIOSPHERE, OAK RIDGE NATL LAB, ENVIRONM SCI DIV, TENNESSEE VALLEY AUTHORITY, USDA, FOREST SERV AB The National Wetlands Inventory of the U.S. Fish and Wildlife Service has prepared large scale (1:24,000) wetland maps for nearly all of the Southern Appalachian Region. Traditional and digital cartographic products are available from the Earth Science Information Centers of the United States Geological Survey and from State-Nn distribution outlets. Most of the materials prepared by the NWI within the region were cooperatively funded by the States and other Federal Agencies. NWI maps describe wetlands in terms of the life form of the dominant vegetation, substrata where vegetation is sparse or lacking, water chemistry, relative duration of inundation or saturation, and special modifiers. The maps display wetland polygons as small as 0.5 hectares in size and linear wetlands as narrow as 8 meters, showing the size, type of wetland, and relative position of the wetland on the landscape. The wetland inventory process is principally a remote sensing task, relying on the interpretation of high altitude color infrared aerial photography, supported with ground truth data and collateral information. The procedure has limitations related to scale, quality, and timing of the aerial photography; experience and training of the photo interpreters; and the wetland types which are to be classified and delineated. Since wetland maps provide a static depiction of a dynamic resource, the NWI conducts periodic wetland status and trends studies to evaluate wetland change in areal extent and the reasons for the change. Although trend surveys are routinely conducted nationally and selectively far regional and local areas, no study to specifically address the wetlands of the Southern Appalachian Region has been developed. RP HEFNER, JM (reprint author), US FISH & WILDLIFE SERV,ATLANTA,GA 30345, USA. NR 18 TC 6 Z9 6 U1 2 U2 4 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 OCT PY 1994 VL 77 IS 3-4 BP 209 EP 216 DI 10.1007/BF00478419 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA QD818 UT WOS:A1994QD81800004 ER PT J AU MURDOCK, NA AF MURDOCK, NA TI RARE AND ENDANGERED PLANTS AND ANIMALS OF SOUTHERN APPALACHIAN WETLANDS SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT Southern-Appalachian-Man-and-the-Biosphere (SAMAB) Conference on Wetland Ecology, Management, and Conservation CY SEP 28-30, 1993 CL KNOXVILLE, TN SP SO APPALACHIAN MAN & BIOSPHERE, OAK RIDGE NATL LAB, ENVIRONM SCI DIV, TENNESSEE VALLEY AUTHORITY, USDA, FOREST SERV AB At least one-third of the threatened and endangered species of the United States live in wetlands. Southern Appalachian bogs and fens, in particular, support a wealth of rare and unique life forms, many of which are found in no other habitat type. In North Carolina alone, nonalluvial mountain wetlands provide habitat for nearly 90 species of plants and animals that are considered rare, threatened, or endangered by the North Carolina Plant Conservation Program, the North Carolina Natural Heritage Program, the North Carolina Wildlife Resources Commission, or the U.S. Fish and Wildlife Service. These species include the bog turtle, mountain sweet pitcher plant, green pitcher plant, swamp pink, bunched arrowhead, and Gray's lily, all of which are either on the federal list of endangered and threatened species or under consideration for that list. Mountain wetland habitats for these species are being destroyed and degraded at an accelerating rate for highway construction and expansion and residential and recreational development, as well as far industrial and agricultural uses. RP MURDOCK, NA (reprint author), US FISH & WILDLIFE SERV,ENDANGERED SPECIES FIELD OFF,330 RIDGEFIELD COURT,ASHEVILLE,NC 28806, USA. NR 47 TC 24 Z9 29 U1 1 U2 16 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 OCT PY 1994 VL 77 IS 3-4 BP 385 EP 405 DI 10.1007/BF00478429 PG 21 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA QD818 UT WOS:A1994QD81800014 ER PT J AU PRODEHL, C MECHIE, J ACHAUER, U KELLER, GR KHAN, MA MOONEY, WD GACIRI, SJ OBEL, JD AF PRODEHL, C MECHIE, J ACHAUER, U KELLER, GR KHAN, MA MOONEY, WD GACIRI, SJ OBEL, JD TI THE KRISP-90 SEISMIC EXPERIMENT - A TECHNICAL REVIEW SO TECTONOPHYSICS LA English DT Article ID KENYA RIFT; TECTONICS AB On the basis of a preliminary experiment in 1985 (KRISP 85), a seismic refraction/wide-angle reflection survey and a teleseismic tomography experiment were jointly undertaken to study the lithospheric structure of the Kenya rift down to depths of greater than 200 km. This report serves as an introduction to a series of subsequent papers and will focus on the technical description of the seismic surveys of the main KRISP 90 effort. The seismic refraction/ wide-angle reflection survey was carried out in a 4-week period in January and February 1990. It consisted of three profiles: one extending along the rift valley from Lake Turkana to Lake Magadi, one crossing the rift at Lake Baringo, and one located on the eastern flank of the rift proper. A total of 206 mobile vertical-component seismographs, with an average station interval of about 2 km, recorded the energy of underwater and borehole explosions to distances of up to about 550 km. During the teleseismic survey an array of 65 seismographs was deployed to record teleseismic, regional and local events for a period of about 7 months from October 1989 to April 1990. The elliptical array spanned the central portion of the rift, with Nakuru at its center, and covered an area about 300 x 200 km, with an average station spacing of 10-30 km. Major scientific goals of the project were to reveal the detailed crustal and upper-mantle structure under the Kenya rift, to study the relationship between deep crustal and mantle structure and the development of sedimentary basins and volcanic features within the rift, to understand the role of the Kenya rift within the Afro-Arabian rift system, and to answer fundamental questions such as the mode and mechanism of continental rifting. C1 UNIV TEXAS,DEPT GEOL SCI,EL PASO,TX 79968. UNIV LEICESTER,DEPT GEOL,LEICESTER LE1 7RH,LEICS,ENGLAND. US GEOL SURVEY,MENLO PK,CA 94025. UNIV NAIROBI,DEPT GEOL,NAIROBI,KENYA. SURVEY KENYA,NAIROBI,KENYA. RP PRODEHL, C (reprint author), UNIV KARLSRUHE,INST GEOPHYS,HERTZSTR 16,D-76187 KARLSRUHE,GERMANY. NR 37 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 33 EP 60 DI 10.1016/0040-1951(94)90168-6 PG 28 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700006 ER PT J AU JACOB, AWB VEES, R BRAILE, LW CRILEY, E AF JACOB, AWB VEES, R BRAILE, LW CRILEY, E TI OPTIMIZATION OF WIDE-ANGLE SEISMIC SIGNAL-TO-NOISE RATIOS AND P-WAVE TRANSMISSION IN KENYA SO TECTONOPHYSICS LA English DT Article ID RIFT; PROFILE; CRUST AB In previous refraction and wide-angle reflection experiments in the Kenya Rift there were problems with poor signal-noise ratios which made good seismic interpretation difficult. Careful planning and preparation for KRISP 90 has substantially overcome these problems and produced excellent seismic sections in a difficult environment. Noise levels were minimized by working, as far as possible, at times of the day when conditions were quiet, while source signals were optimized by using dispersed charges in water where it was available and waterfilled boreholes in most cases where it was not. Seismic coupling at optimum depth in water has been found to be more than 100 times greater than it is in a borehole in dry loosely compacted material. Allowing for the source coupling, a very marked difference has been found between the observation ranges in the rift and those on the flanks, where the observation ranges are greater. These appear to indicate a significant difference in seismic transmission through the two types of crust. C1 TECH UNIV CLAUSTHAL,INST GEOPHYS,W-3392 CLAUSTHAL ZELLERFE,GERMANY. PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. US GEOL SURVEY,MENLO PK,CA 94025. RP JACOB, AWB (reprint author), DUBLIN INST ADV STUDIES,5 MERRION SQ,DUBLIN 2,IRELAND. NR 24 TC 12 Z9 12 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 61 EP 79 DI 10.1016/0040-1951(94)90169-4 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700007 ER PT J AU MECHIE, J KELLER, GR PRODEHL, C GACIRI, S BRAILE, LW MOONEY, WD GAJEWSKI, D SANDMEIER, KJ AF MECHIE, J KELLER, GR PRODEHL, C GACIRI, S BRAILE, LW MOONEY, WD GAJEWSKI, D SANDMEIER, KJ TI CRUSTAL STRUCTURE BENEATH THE KENYA RIFT FROM AXIAL PROFILE DATA SO TECTONOPHYSICS LA English DT Article ID SYNTHETIC SEISMOGRAMS; TECTONIC EVOLUTION; GREGORY RIFT; TURKANA RIFT; VALLEY; STRATIGRAPHY AB Modelling of the KRISP 90 axial line data shows that major crustal thinning occurs along the axis of the Kenya Rift from Moho depths of 35 km in the south beneath the Kenya Dome in the vicinity of Lake Naivasha to 20 km in the north beneath Lake Turkana. Low P-n velocities of 7.5-7.7 km/s are found beneath the whole of the axial line. The results indicate that crustal extension increases to the north and that the low P-n velocities are probably caused by magma (partial melt) rising from below and being trapped in the uppermost kilometres of the mantle. Along the axial line, the rift infill consisting of volcanics and a minor amount of sediments varies in thickness from zero where Precambrian crystalline basement highs occur to 5-6 km beneath the lakes Turkana and Naivasha. Analysis of the P-g phase shows that the upper crystalline crust has velocities of 6.1-6.3 km/s. Bearing in mind the Cainozoic volcanism associated with the rift, these velocities most probably represent Precambrian basement intruded by small amounts of igneous material. The boundary between the upper and lower crusts occurs at about 10 km depth beneath the northern part of the rift and 15 km depth beneath the southern part of the rift. The upper part of the lower crust has velocities of 6.4-6.5 km/s. The basal crustal layer which varies in thickness from a maximum of 2 km in the north to around 9 km in the south has a velocity of about 6.8 km/s. C1 UNIV KARLSRUHE,INST GEOPHYS,D-76187 KARLSRUHE,GERMANY. UNIV TEXAS,DEPT GEOL SCI,EL PASO,TX 79968. UNIV NAIROBI,DEPT GEOL,NAIROBI,KENYA. PURDUE UNIV,DEPT GEOSCI,W LAFAYETTE,IN 47907. US GEOL SURVEY,OFF EARTHQUAKE RES,MENLO PK,CA 94025. TECH UNIV CLAUSTHAL,INST GEOPHYS,W-3392 CLAUSTHAL ZELLERFE,GERMANY. RI Gajewski, Dirk/C-1077-2011 NR 35 TC 63 Z9 63 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 179 EP 200 DI 10.1016/0040-1951(94)90176-7 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700014 ER PT J AU KELLER, GR MECHIE, J BRAILE, LW MOONEY, WD PRODEHL, C AF KELLER, GR MECHIE, J BRAILE, LW MOONEY, WD PRODEHL, C TI SEISMIC STRUCTURE OF THE UPPERMOST MANTLE BENEATH THE KENYA RIFT SO TECTONOPHYSICS LA English DT Article ID SYNTHETIC SEISMOGRAMS; CRUSTAL STRUCTURE; SAUDI-ARABIA; EASTERN; SEA; ANISOTROPY; FLOW AB A major goal of the Kenya Rift International Seismic Project (KRISP) 1990 experiment was the determination of deep lithospheric structure. In the refraction/wide-angle reflection part of the KRISP effort, the experiment was designed to obtain arrivals to distances in excess of 400 km. Phases from interfaces within the mantle were recorded from many shotpoints, and by design, the best data were obtained along the axial profile. Reflected arrivals from two thin (< 10 km), high-velocity layers were observed along this profile and a refracted arrival was observed from the upper high-velocity layer. These mantle phases were observed on record sections from four axial profile shotpoints so overlapping and reversed coverage was obtained. Both high-velocity layers are deepest beneath Lake Turkana and become more shallow southward as the apex of the Kenya dome is approached. The first layer has a velocity of 8.05-8.15 km/s, is at a depth of about 45 km beneath Lake Turkana, and is observed at depths of about 40 km to the south before it disappears near the base of the crust. The deeper layer has velocities ranging from 7.7 to 7.8 km/s in the south to about 8.3 km/s in the north, has a similar dip as the upper one, and is found at depths of 60-65 km. Mantle arrivals outside the rift valley appear to correlate with this layer. The large amounts of extrusive volcanics associated with the rift suggest compositional anomalies as an explanation for the observed velocity structure. However, the effects of the large heat anomaly associated with the rift indicate that composition alone cannot explain the high-velocity layers observed. These layers require some anisotropy probably due to the preferred orientation of olivine crystals. The seismic model is consistent with hot mantle material rising beneath the Kenya dome in the southern Kenya rift and north-dipping shearing along the rift axis near the base of the lithosphere beneath the northern Kenya rift. This implies lithosphere thickening towards the north and is consistent with a thermal thinning of the lithosphere from below in the south changing to thinning of the lithosphere due to stretching in the north. C1 UNIV KARLSRUHE,INST GEOPHYS,D-76187 KARLSRUHE,GERMANY. PURDUE UNIV,DEPT GEOSCI,W LAFAYETTE,IN 47907. US GEOL SURVEY,OFF EARTQUAKE RES,MENLO PK,CA 94025. RP KELLER, GR (reprint author), UNIV TEXAS,DEPT GEOL SCI,EL PASO,TX 79968, USA. NR 42 TC 36 Z9 36 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 201 EP 216 DI 10.1016/0040-1951(94)90177-5 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700015 ER PT J AU MOONEY, WD CHRISTENSEN, NI AF MOONEY, WD CHRISTENSEN, NI TI COMPOSITION OF THE CRUST BENEATH THE KENYA RIFT SO TECTONOPHYSICS LA English DT Article ID COMPRESSIONAL WAVE VELOCITIES; ROCKS; TEMPERATURE; EVOLUTION; PRESSURE AB We infer the composition of the crust beneath and on the flanks of the Kenya rift based on a comparison of the KRISP-90 crustal velocity structure with laboratory measurements of compressional-wave velocities of rock samples from Kenya. The rock samples studied, which are representative of the major lithologies exposed in Kenya, include volcanic tuffs and flows (primarily basalts and phonolites), and felsic to intermediate composition gneisses. This comparison indicates that the upper crust (5-12 km depth) consists primarily of quartzo-feldspathic gneisses and schists similar to rocks exposed on the flanks of the rift, whereas the middle crust (12-22 km depth) consists of more mafic, hornblende-rich metamorphic rocks, probably intruded by mafic rocks beneath the rift axis. The lower crust on the flanks of the rift may consist of mafic granulite facies rocks. Along the rift axis, the lower crust varies in thickness from 9 km in the southern rift to only 2-3 km in the north, and has a seismic velocity substantially higher than the samples investigated in this study. The lower crust of the rift probably consists of a crust/mantle mix of high-grade metamorphic rocks, mafic intrusives, and an igneous mafic residuum accreted to the base of the crust during differentiation of a melt derived from the upper mantle. C1 PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. RP MOONEY, WD (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS977,MENLO PK,CA 94025, USA. NR 30 TC 21 Z9 21 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 391 EP 408 DI 10.1016/0040-1951(94)90186-4 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700024 ER PT J AU KELLER, GR PRODEHL, C MECHIE, J FUCHS, K KHAN, MA MAGUIRE, PKH MOONEY, WD ACHAUER, U DAVIS, PM MEYER, RP BRAILE, LW NYAMBOK, IO THOMPSON, GA AF KELLER, GR PRODEHL, C MECHIE, J FUCHS, K KHAN, MA MAGUIRE, PKH MOONEY, WD ACHAUER, U DAVIS, PM MEYER, RP BRAILE, LW NYAMBOK, IO THOMPSON, GA TI THE EAST-AFRICAN RIFT SYSTEM IN THE LIGHT OF KRISP-90 SO TECTONOPHYSICS LA English DT Article ID ACTIVE CONTINENTAL RIFTS; SEISMIC REFRACTION LINE; UPPER MANTLE BENEATH; KENYA RIFT; CRUSTAL STRUCTURE; GREGORY RIFT; RIO-GRANDE; NORTHERN KENYA; RHINE GRABEN; BAIKAL RIFT AB On the basis of a test experiment in 1985 (KRISP 85) an integrated seismic-refraction/teleseismic survey (KRISP 90) was undertaken to study the deep structure beneath the Kenya rift down to depths of 100-150 km. This paper summarizes the highlights of KRISP 90 as reported in this volume and discusses their broad implications as well as the structure of the Kenya rift in the general framework of other continental rifts. Major scientific goals of this phase of KRISP were to reveal the detailed crustal and upper mantle structure under the Kenya rift, to study the relationship between mantle updoming and the development of sedimentary basins and other shallow structures within the rift, to understand the role of the Kenya rift within the Afro-Arabian rift system and within a global perspective, and to elucidate fundamental questions such as the mode and mechanism of continental rifting. The KRISP results clearly demonstrate that the Kenya rift is associated with sharply defined lithospheric thinning and very low upper mantle velocities down to depths of over 150 km. In the south-central portion of the rift, the lithospheric mantle has been thinned much more than the crust. To the north, high-velocity layers detected in the upper mantle appear to require the presence of anistropy in the form of the alignment of olivine crystals. Major axial variations in structure were also discovered, which correlate very well with variations in the amount of extension, the physiographic width of the rift valley, the regional topography, and the regional gravity anomalies. Similar relationships are particularly well documented in the Rio Grande rift. To the extent that truly comparable data sets are available, the Kenya rift shares many features with other rift zones. For example, crustal structure under the Kenya, Rio Grande, and Baikal rifts and the Rhine Graben is generally symmetrically centered on the rift valleys. However, the Kenya rift is distinctive, but not unique, in terms of the amount of volcanism. This volcanic activity would suggest large-scale modification of the crust by magmatism. C1 UNIV KARLSRUHE, INST GEOPHYS, D-76187 KARLSRUHE, GERMANY. UNIV LEICESTER, DEPT GEOL, LEICESTER LE1 7RH, LEICS, ENGLAND. US GEOL SURVEY, OFF EARTHQUAKE RES, MENLO PK, CA 94025 USA. UNIV STRASBOURG, INST PHYS GLOBE, F-67084 STRASBOURG, FRANCE. UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. UNIV WISCONSIN, DEPT GEOL & GEOPHYS, MADISON, WI 53706 USA. PURDUE UNIV, DEPT EARTH & ATMOSPHER SCI, W LAFAYETTE, IN 47907 USA. UNIV NAIROBI, DEPT GEOL, NAIROBI, KENYA. STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. RP KELLER, GR (reprint author), UNIV TEXAS, DEPT GEOL SCI, EL PASO, TX 79968 USA. RI Davis, Paul/E-7151-2012 NR 96 TC 37 Z9 37 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 EI 1879-3266 J9 TECTONOPHYSICS JI Tectonophysics PD SEP 30 PY 1994 VL 236 IS 1-4 BP 465 EP 483 DI 10.1016/0040-1951(94)90190-2 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL447 UT WOS:A1994PL44700028 ER PT J AU LINDE, AT SACKS, IS JOHNSTON, MJS HILL, DP BILHAM, RG AF LINDE, AT SACKS, IS JOHNSTON, MJS HILL, DP BILHAM, RG TI INCREASED PRESSURE FROM RISING BUBBLES AS A MECHANISM FOR REMOTELY TRIGGERED SEISMICITY SO NATURE LA English DT Article ID LONG-VALLEY CALDERA; VOLCANIC SYSTEMS; CALIFORNIA AB AFTERSHOCKS Of large earthquakes tend to occur close to the main rupture zone, and can be used to constrain its dimensions. But following the 1992 Landers earthquake (magnitude M(w)= 7.3) in southern California,many aftershocks were reported(1) in areas remote from the mainshock. Intriguingly, this remote seismicity occurred in small clusters near active volcanic and geothermal systems. For one of these clusters (Long Valley, about 400 km from the Landers earthquake), crustal deformation associated with the seismic activity was also monitored, Here we argue that advective overpressure(2-7) provides a viable mechanism for remote seismicity triggered by the Landers earthquake. Both the deformation and seismicity data are consistent with pressure increases owing to gas bubbles rising slowly within a volume of magma. These bubbles may have been shaken loose during the passage of seismic waves generated by the mainshock. C1 US GEOL SURVEY,MENLO PK,CA 94025. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. RP LINDE, AT (reprint author), CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,5241 BROAD BRANCH RD NW,WASHINGTON,DC 20015, USA. OI Bilham, Roger/0000-0002-5547-4102 NR 20 TC 84 Z9 85 U1 0 U2 14 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD SEP 29 PY 1994 VL 371 IS 6496 BP 408 EP 410 DI 10.1038/371408a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PJ285 UT WOS:A1994PJ28500039 ER PT J AU VIDALE, JE AF VIDALE, JE TI GEOPHYSICS - A MYSTERY IN THE MANTLE SO NATURE LA English DT Editorial Material ID NORTHWEST PACIFIC; ISLAND ARCS; DISCONTINUITY; BENEATH; TRANSITION; ZONE; IRON RP VIDALE, JE (reprint author), US GEOL SURVEY,OFF EARTHQUAKES & VOLCANOES,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 19 TC 0 Z9 0 U1 0 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD SEP 22 PY 1994 VL 371 IS 6495 BP 288 EP 288 DI 10.1038/371288a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PH254 UT WOS:A1994PH25400029 ER PT J AU MORROW, CA LOCKNER, DA AF MORROW, CA LOCKNER, DA TI PERMEABILITY DIFFERENCES BETWEEN SURFACE-DERIVED AND DEEP DRILLHOLE CORE SAMPLES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CAJON PASS; ROCKS AB Laboratory tests reveal that the permeability of samples obtained from deep boreholes is often lower and more sensitive to pressure than the permeability of common surface-derived crystalline rocks reported in the literature. We attribute the differences in permeability behavior to the fact that surface rocks have histories of unloading, weathering and retrograde metamorphism which are not comparable to that of the deeper rocks. Weathering products that line cracks and pores of surface rocks and make these openings more difficult to close as pressure increases may account for the relatively low pressure-sensitivity of permeability. Stress-relief cracking in the borehole samples can also reduce the pressure sensitivity. These results have important implications for models that incorporate assumptions about the transport properties of rock at depth, such as models of heat transport or fluid pressure buildup, because many models are based on the properties of common surface-derived rocks. Other physical properties that are controlled by cracks and pores, such as seismic velocity and electrical resistivity, may be similarly affected by differences between surface-derived and deep rocks. RP MORROW, CA (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 13 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 SEP 15 PY 1994 VL 21 IS 19 BP 2151 EP 2154 DI 10.1029/94GL01936 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PH573 UT WOS:A1994PH57300020 ER PT J AU HOLBROOK, WS PURDY, GM SHERIDAN, RE GLOVER, L TALWANI, M EWING, J HUTCHINSON, D AF HOLBROOK, WS PURDY, GM SHERIDAN, RE GLOVER, L TALWANI, M EWING, J HUTCHINSON, D TI SEISMIC STRUCTURE OF THE US MID-ATLANTIC CONTINENTAL-MARGIN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CRUSTAL STRUCTURE; EAST-COAST; VELOCITY STRUCTURE; CAROLINA TROUGH; RIFT ZONES; MAGMATISM; EMBAYMENT; BOUNDARY; BASALTS; IBERIA AB Multichannel and wide-angle seismic data collected off Virginia during the 1990 EDGE Mid-Atlantic seismic experiment provide the most detailed image to date of the continent-ocean transition on the U.S. Atlantic margin. Multichannel data were acquired using a 10,800 in(3) (177 L) airgun array and 6-km-long streamer, and coincident wide-angle data were recorded by ten ocean bottom seismic instruments. A velocity model constructed by inversion of wide-angle and vertical-incidence travel times shows strong lateral changes in deep-crustal structure across the margin. Lower-crustal velocities are 6.8 km/s in rifted continental crust, increase to 7.5 km/s beneath the outer continental shelf, and decrease to 7.0 km/s in oceanic crust. Prominent seaward-dipping reflections within basement lie within layers of average velocity 6.3-6.5 km/s, consistent with their interpretation as basalts extruded during rifting. The high-velocity lower crust and seaward-dipping reflections comprise a 100-km-wide, 25-km-thick ocean-continent transition zone that consists almost entirely of mafic igneous material accreted to the margin during continental breakup. The boundary between rifted continental crust and this thick igneous crust is abrupt, occupying only about 20 km of the margin. Appalachian intracrustal reflectivity largely disappears across this boundary as velocity increases from 5.9 km/s to > 7.0 km/s, implying that the reflectivity is disrupted by massive intrusion and that very little continental crust persists seaward of the reflective crust. The thick igneous crust is spatially correlated with the East Coast magnetic anomaly, implying that the basalts and underlying intrusives cause the anomaly. The details of the seismic structure and lack of independent evidence for an appropriately located hotspot in the central Atlantic imply that nonplume processes are responsible for the igneous material. C1 VIRGINIA POLYTECH INST & STATE UNIV, DEPT GEOL SCI, BLACKSBURG, VA 24061 USA. US GEOL SURVEY, ATLANTIC MARINE BRANCH, WOODS HOLE, MA 02543 USA. RUTGERS STATE UNIV, DEPT GEOL SCI, NEW BRUNSWICK, NJ 08903 USA. HOUSTON ADV RES CTR, THE WOODLANDS, TX 77381 USA. RP HOLBROOK, WS (reprint author), WOODS HOLE OCEANOG INST, DEPT GEOL & GEOPHYS, WOODS HOLE, MA 02543 USA. RI Holbrook, W. Steven/G-9800-2011 OI Holbrook, W. Steven/0000-0003-0065-8841 NR 55 TC 68 Z9 68 U1 0 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 SEP 10 PY 1994 VL 99 IS B9 BP 17871 EP 17891 DI 10.1029/94JB00729 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700016 ER PT J AU HARLAN, SS SNEE, LW GEISSMAN, JW BREARLEY, AJ AF HARLAN, SS SNEE, LW GEISSMAN, JW BREARLEY, AJ TI PALEOMAGNETISM OF THE MIDDLE PROTEROZOIC LARAMIE ANORTHOSITE COMPLEX AND SHERMAN GRANITE, SOUTHERN LARAMIE RANGE, WYOMING AND COLORADO SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID KAPUSKASING STRUCTURAL ZONE; MALOIN-RANCH PLUTON; GEOCHEMICAL EVOLUTION; CARBONATITE COMPLEX; THERMAL EVOLUTION; KEWEENAWAN ROCKS; NORTH-AMERICA; LAKE-SUPERIOR; CHEYENNE BELT; AGE AB We present the results of a combined paleomagnetic and Ar-40/Ar-39 geochronologic investigation of the Middle Proterozoic Laramie anorthosite complex and Sherman Granite in the southern Laramie Range of Wyoming and Colorado. Anorthosites and monzosyenites of the Laramie anorthosite complex yield a well-defined characteristic magnetization of northeast declination (D) and moderate negative inclination (I), although antipodal normal and reverse polarity magnetizations are present at three sites. A grand mean direction from 29 of 35 sites in the complex is D = 44.6 degrees, I = -48.7 degrees (k = 77.4, alpha(95) = 3.1 degrees). Alternating field (AF) and thermal demagnetization behavior and rock magnetic experiments indicate that magnetization is carried by low-Ti titanomagnetite of single or pseudo-single domain character that occurs as elongate to rod-shaped inclusions in plagioclase and potassium feldspar. The Sherman Granite contains a dual polarity magnetization that is less well defined than that of the Laramie anorthosite complex but similar in declination and inclination (D = 53.1 degrees, I = -48.1 degrees, k = 46.5, alpha(95) = 7.6 degrees, n = 8/14 sites); rock magnetic data indicate the primary carrier of remanence in Sherman Granite is magnetite. The Ar-40/Ar-39 geochronologic data from Sherman Granite hornblende, biotite, and microcline indicate that subsolidus cooling was moderate to relatively rapid through the range of temperatures over which magnetization was blocked and that the age of remanence is about 1415 Ma, Microcline data indicate that the Laramie anorthosite complex and Sherman Granite have probably not been thermally remagnetized. Paleomagnetic poles from the Laramie anorthosite complex and Sherman Granite are indistinguishable at the 95% confidence level, and individual virtual geomagnetic poles (VGPs) from both units are combined to provide a mean pole at 215.0 degrees E, 6.7 degrees S (K = 46.9, A(95) = 3.5 degrees, N = 37 VGPs). The location of this pole is similar to paleomagnetic poles derived from 1480 Ma to 1450 Ma intrusions elsewhere in North America, but it plots significantly north of those from Middle Proterozoic sedimentary strata of the Belt Supergroup and Sibley Group. In addition to the characteristic magnetization, samples from some sites in Sherman Granite contain a remanence of southeast declination and shallow negative inclination (D = 154.9 degrees, I = -16.0 degrees, k = 90.6, alpha(95) = 9.7 degrees, n = 4 sites). This secondary magnetization was probably acquired during late Paleozoic time. C1 UNIV NEW MEXICO, DEPT EARTH & PLANETARY SCI, ALBUQUERQUE, NM 87131 USA. RP HARLAN, SS (reprint author), US GEOL SURVEY, DENVER FED CTR, POB 25046, MS 963, DENVER, CO 80225 USA. NR 136 TC 29 Z9 30 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 SEP 10 PY 1994 VL 99 IS B9 BP 17997 EP 18020 DI 10.1029/94JB00580 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700025 ER PT J AU CORTINI, M BARTON, CC AF CORTINI, M BARTON, CC TI CHAOS IN GEOMAGNETIC REVERSAL RECORDS - A COMPARISON BETWEEN EARTHS MAGNETIC-FIELD DATA AND MODEL DISK DYNAMO DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SHORT TIMESCALES; CAMPI FLEGREI; TIME-SERIES; ATTRACTOR; CLIMATE; DIMENSION; FREQUENCY; SEQUENCES; ROTATION; CALDERA AB The Earth's geomagnetic field reverses its polarity at irregular time intervals. However, it is not clear whether a reversal is a deterministic (low-dimensional) or a random (high-dimensional) process; the duration-frequency distribution of the polarity time intervals resembles those generated by random processes, but many models suggest that a geomagnetic field reversal can be the outcome of a deterministic dynamics, that of the convection in the Earth's outer core. The latter, in turn, is only a part of an extremely complex system, made up of both terrestrial and extraterrestrial subsystems nonlinearly interacting with each other over a wide range of time scales. We studied the geomagnetic field reversal patterns by means of several techniques of nonlinear dynamics and compared the results obtained on actual geomagnetic reversal data with synthetic reversal sequences generated by the Rikitake and Chillingworth-Holmes models of the Earth's magnetic field. We analyzed both the geomagnetic and the synthetic reversal scales by nonlinear forecasting and found that we cannot predict the geomagnetic reversal sequence with nonlinear forecasting. Predictability of the synthetic data varies widely depending on the model parameters. Phase portraits of data obtained from the magnetic field models show fractal structures similar to those associated with the Lorenz attractor. We measured the correlation dimension Dc of the synthetic and geomagnetic data by means of the Grassberger-Procaccia method and found that Dc always has a value of about one for the synthetic data. The correlation integrals for the geomagnetic reversal sequence behave very differently from those of randomized reversal sequences and suggest that the Earth's geomagnetic field reversal dynamics is not random. However, the limited size of the magnetic reversal data set (282 points) and the poor convergence of the correlation integrals make a quantitative assessment of low-dimensional chaos impossible. Our analysis sets a lower limit to the correlation dimension of the geomagnetic reversal dynamics: D-C > 3. C1 UNIV NAPLES FEDERICO II, DIPARTIMENTO GEOFIS & VULCANOL, I-80138 NAPLES, ITALY. RP CORTINI, M (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 940, BOX 25046, DENVER, CO 80225 USA. NR 64 TC 15 Z9 15 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 SEP 10 PY 1994 VL 99 IS B9 BP 18021 EP 18033 DI 10.1029/94JB01237 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700026 ER PT J AU SAVAGE, JC LISOWSKI, M GROSS, WK KING, NE SVARC, JL AF SAVAGE, JC LISOWSKI, M GROSS, WK KING, NE SVARC, JL TI STRAIN ACCUMULATION NEAR YUCCA MOUNTAIN, NEVADA, 1983-1993 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CRUSTAL DEFORMATION; CALIFORNIA; EARTHQUAKE; PRECISION AB Over the decade 1983-1993 the U.S. Geological Survey has measured the deformation of a 50-km-aperture trilateration network centered on Yucca Mountain the proposed disposal site for high-level nuclear waste in the United States. The network was surveyed in 1983, 1984, and 1993. The average annual principal strain rates are 0.010 +/- 0.020 mu strain/yr N90 degrees W +/- 24 degrees and -0.009 +/- 0.021 mu strain/yr N00 degrees E +/- 24 degrees, indicating no significant strain accumulation. The southeast corner of the network was disturbed on June 29, 1992, by the Little Skull Mountain earthquake (M(s) = 5.4), the epicenter of which is about 20 km southeast of the Yucca Mountain site. Using the seismically determined fault plane (dip 54 degrees S55 degrees E), we find that 0.580 +/- 0.075 m of normal slip on a 5-km square rupture surface at a depth of about 8 km provides a good fit to the observed deformation in the southeast corner of the network. The inferred seismic moment is (4.4 +/- 0.6) x 10(17) N m, which compares well with the observed seismic moment of 4.1 x 10(17) N m. RP SAVAGE, JC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 10 TC 13 Z9 13 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 SEP 10 PY 1994 VL 99 IS B9 BP 18103 EP 18107 DI 10.1029/94JB01551 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700034 ER PT J AU SAVAGE, JC LISOWSKI, M KING, NE GROSS, WK AF SAVAGE, JC LISOWSKI, M KING, NE GROSS, WK TI STRAIN ACCUMULATION ALONG THE LAGUNA SALADA FAULT, BAJA-CALIFORNIA, MEXICO SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID IMPERIAL-VALLEY EARTHQUAKE AB Strain accumulation observed over the 1978-1991 interval in a 30 x 100 km aperture trilateration network spanning the Laguna Salada fault is described by the principal strain rates 0.101 +/- 0.012 mu strain/yr N80 degrees E+/-2 degrees and -0.021 +/- 0.012 mu strain/yr N10 degrees W+/-2 degrees, extension reckoned positive. These strain accumulation rates have been corrected to remove coseismic effects of the nearby 1979 Imperial Valley (M = 6.5), 1980 Victoria (Baja California) (M = 6.4), 1987 Superstition Hills (M = 6.5), and 1987 Elmore Ranch (M = 5.9) earthquakes. The observed strain rates indicate extension at a rate of about 0.08 mu strain/yr perpendicular to the trend (N35 degrees W) of the Salton trough as well as a right-lateral tenser shear strain rate 0.05 mu strain/yr across it. The extension perpendicular to the trough is observed neither farther north near the Salton Sea nor farther south across the Gulf of California, However, Holocene slip on the Laguna Salada fault, about equal parts right-lateral and normal slip, is consistent with the observed strain accumulation. A simple dislocation model intended to explain the observed strain accumulation as a product of slip at depth on the Laguna Salada fault would require that the fault be listric. RP SAVAGE, JC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS-977, MENLO PK, CA 94025 USA. NR 16 TC 14 Z9 14 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 1994 VL 99 IS B9 BP 18109 EP 18116 DI 10.1029/94JB01471 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700035 ER PT J AU BEKINS, B MCCAFFREY, AM DREISS, SJ AF BEKINS, B MCCAFFREY, AM DREISS, SJ TI INFLUENCE OF KINETICS ON THE SMECTITE TO ILLITE TRANSITION IN THE BARBADOS ACCRETIONARY PRISM SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID DRILLING PROJECT LEG-78A; RIDGE COMPLEX; BURIAL DIAGENESIS; FLUID PRESSURES; LEG 110; FLOW; TRANSFORMATION; METAMORPHISM; MECHANISM; SEDIMENT AB Low chloride pore fluids observed along faults in clay-rich accretionary complexes are commonly attributed to the release of interlayer water during the smectite to illite transformation. However, to date, there has been no thorough analysis of the location and quantity of fluids that may be generated by this mechanism. To address this problem, a temperature and time dependent rate expression describing the dehydration reaction was coupled to a kinematic model of the northern Barbados accretionary complex. Temperatures in the complex were estimated by modeling heat flow through the prism sediments as they thicken arcward. The sediments' temperature-time histories were computed using a model fdr the velocities of sediment motion through the complex. In this model the prism sediments follow uniformly diverging paths from the toe while the underthrust sediments undergo uniaxial strain. The model predictions andre validated against clay mineralogy data from Barbados Island mudstones. Our results show that the location of the peak dehydration rate is 20 km farther arcward in the underthrust sediments than in the prism complex. The fresh water produced by the reaction results in pore waters that are 10-30% fresher at a distance of 50-70 km from the prism toe. This constraint indicates a probable fluid migration path of more than 50 km from the reaction zone to the sites where freshened pore fluids have been observed. The peak rate of fluid production when expressed as the volume of fluid per volume of sediment per second is 2X10(-15). C1 UNIV CALIF SANTA CRUZ, DEPT EARTH SCI, SANTA CRUZ, CA 95064 USA. RP BEKINS, B (reprint author), US GEOL SURVEY, MS 496, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 35 TC 40 Z9 41 U1 1 U2 9 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 1994 VL 99 IS B9 BP 18147 EP 18158 DI 10.1029/94JB01187 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700037 ER PT J AU RECHES, Z LOCKNER, DA AF RECHES, Z LOCKNER, DA TI NUCLEATION AND GROWTH OF FAULTS IN BRITTLE ROCKS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COMPRESSIVE STRESS STATES; CRACK GROWTH; FAILURE; GRANITE; SOLIDS; SPECIMENS AB We present a model for the nucleation and growth of faults in intact brittle rocks. The model is based on recent experiments that utilize acoustic emission events to monitor faulting processes in Westerly granite. In these experiments a fault initiated at one site without significant preceding damage. The fault propagated in its own plane with a leading zone of intense microcracking. We propose here that faults ire granites nucleate and propagate by the interaction of tensile microcracks in the following style. During early loading, tensile microcracking occurs randomly, with no significant crack interaction and with no relation to the location or inclination of the future fault. As the load reaches the ultimate strength, nucleation initiates when a few tensile microcracks interact and enhance the dilation of one another. They create a process zone that is a region with closely spaced microcracks. In highly loaded rock, the stress field associated with microcrack dilation forces crack interaction to spread in an unstable manner and recursive geometry. Thus the process zone propagates unstably into the intact rock. As the process zone lengthens, its central part yields by shear and a fault nucleus forms. The fault nucleus grows in the wake of the propagating process zone. The stress fields associated with shear along the fault further enhance the microcrack dilation in the process zone. The analysis shows that faults should propagate in their own plane, making an angle of 20 degrees-30 degrees with the maximum compression axis. This model provides a physical basis for ''internal friction,'' the empirical parameter of the Coulomb criterion. C1 HEBREW UNIV JERUSALEM, DEPT GEOL, IL-91904 JERUSALEM, ISRAEL. RP RECHES, Z (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 970, MENLO PK, CA 94025 USA. NR 33 TC 203 Z9 205 U1 2 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 SEP 10 PY 1994 VL 99 IS B9 BP 18159 EP 18173 DI 10.1029/94JB00115 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG767 UT WOS:A1994PG76700038 ER PT J AU BELTON, MJS CHAPMAN, CR VEVERKA, J KLAASEN, KP HARCH, A GREELEY, R GREENBERG, R HEAD, JW MCEWEN, A MORRISON, D THOMAS, PC DAVIES, ME CARR, MH NEUKUM, G FANALE, FP DAVIS, DR ANGER, C GIERASCH, PJ INGERSOLL, AP PILCHER, CB AF BELTON, MJS CHAPMAN, CR VEVERKA, J KLAASEN, KP HARCH, A GREELEY, R GREENBERG, R HEAD, JW MCEWEN, A MORRISON, D THOMAS, PC DAVIES, ME CARR, MH NEUKUM, G FANALE, FP DAVIS, DR ANGER, C GIERASCH, PJ INGERSOLL, AP PILCHER, CB TI FIRST IMAGES OF ASTEROID-243-IDA SO SCIENCE LA English DT Article ID SOLAR-SYSTEM; FAMILIES; EVOLUTION; PHOBOS AB The first images of the asteroid 243 Ida from Galileo show an irregular object measuring 56 kilometers by 24 kilometers by 21 kilometers. Its surface is rich in geologic features, including systems of grooves, blocks, chutes, albedo features, crater chains, and a full range of crater morphologies. The largest blocks may be distributed nonuniformly across the surface; lineaments and dark-floored craters also have preferential locations. Ida is interpreted to have a substantial regolith. The high crater density and size-frequency distribution (-3 differential power-law index) indicate a surface in equilibrium with saturated cratering. A minimum model crater age for Ida-and therefore for the Koronis family to which Ida belongs-is estimated at 1 billion years, older than expected. C1 SCI APPLICAT INT CORP,INST PLANETARY SCI,TUCSON,AZ 85705. NATL OPT ASTRON OBSERV,TUCSON,AZ 85719. CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853. CALTECH,JET PROP LAB,PASADENA,CA 91109. ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287. UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. BROWN UNIV,DEPT GEOL,PROVIDENCE,RI 02912. US GEOL SURVEY,FLAGSTAFF,AZ 86001. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RAND CORP,SANTA MONICA,CA 90406. US GEOL SURVEY,MENLO PK,CA 94025. DEUTSCH FORSCH ANSTALT LUFT & RAUMFAHRT,INST PLANETARY EXPLORAT,BERLIN,GERMANY. UNIV HAWAII,INST GEOPHYS,HONOLULU,HI 96822. INST SPACE & TERR SCI,CONCORD L4K 3C8,ON,CANADA. CALTECH,PASADENA,CA 91125. NASA,WASHINGTON,DC 20546. NR 33 TC 94 Z9 94 U1 1 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 9 PY 1994 VL 265 IS 5178 BP 1543 EP 1547 DI 10.1126/science.265.5178.1543 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PF336 UT WOS:A1994PF33600023 PM 17801529 ER PT J AU MOORE, DE LOCKNER, DA BYERLEE, JD AF MOORE, DE LOCKNER, DA BYERLEE, JD TI REDUCTION OF PERMEABILITY IN GRANITE AT ELEVATED-TEMPERATURES SO SCIENCE LA English DT Article ID SAN-ANDREAS FAULT; EARTHQUAKES; GRADIENT; WATER; FLOW AB The addition of hydrothermal fluids to heated, intact granite leads to permeability reductions in the temperature range of 300 degrees to 500 degrees C, with the rate of change generally increasing with increasing temperature. The addition of gouge enhances the rate of permeability reduction because of the greater reactivity of the fine material. Flow rate is initially high in a throughgoing fracture but eventually drops to the level of intact granite. These results support the fault-valve model for the development of mesothermal ore deposits, in which seals are termed at the base of the seismogenic zone of high-angle thrust faults. The lower temperature results yield varying estimates of mineral-sealing rates at shallower depths in fault zones, although they generally support the hypothesis that such seals develop in less time than the recurrence interval for moderate to large earth-quakes on the San Andreas fault. RP MOORE, DE (reprint author), US GEOL SURVEY,MAIL STOP 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 23 TC 80 Z9 86 U1 3 U2 15 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 9 PY 1994 VL 265 IS 5178 BP 1558 EP 1561 DI 10.1126/science.265.5178.1558 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PF336 UT WOS:A1994PF33600027 PM 17801532 ER PT J AU STEIN, RS KING, GCP LIN, J AF STEIN, RS KING, GCP LIN, J TI STRESS TRIGGERING OF THE 1994 M=6.7 NORTHRIDGE, CALIFORNIA, EARTHQUAKE BY ITS PREDECESSORS SO SCIENCE LA English DT Article ID SAN-ANDREAS FAULT; FERNANDO EARTHQUAKE; SOUTHERN-CALIFORNIA; LANDER EARTHQUAKE; FOCAL MECHANISMS; STATIC STRESS; SEQUENCE; DEFORMATION; SEISMICITY; ADJACENT AB A model of stress transfer implies that earthquakes in 1933 and 1952 increased the Coulomb stress toward failure at the site of the 1971 San Fernando earthquake. The 1971 earthquake in turn raised stress and produced aftershocks at the site of the 1987 Whittier Narrows and 1994 Northridge ruptures. The Northridge main shock raised stress in areas where its aftershocks and surface faulting occurred. Together, the earthquakes with moment magnitude M greater than or equal to 6 near Los Angeles since 1933 have stressed parts of the Oak Ridge, Sierra Madre, Santa Monica Mountains, Elysian Park, and Newport-Inglewood faults by more than 1 bar. Although too small to cause earthquakes, these stress changes can trigger events if the crust is already near failure or advance future earthquake occurrence if it is not. C1 INST PHYS GLOBE STRASBOURG, F-67084 STRASBOURG, FRANCE. WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. RP US GEOL SURVEY, MAIL STOP 977, MENLO PK, CA 94025 USA. NR 35 TC 218 Z9 238 U1 1 U2 22 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 SEP 2 PY 1994 VL 265 IS 5177 BP 1432 EP 1435 DI 10.1126/science.265.5177.1432 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PE733 UT WOS:A1994PE73300044 PM 17833817 ER PT J AU BROCHER, TM MCCARTHY, J HART, PE HOLBROOK, WS FURLONG, KP MCEVILLY, TV HOLE, JA KLEMPERER, SL AF BROCHER, TM MCCARTHY, J HART, PE HOLBROOK, WS FURLONG, KP MCEVILLY, TV HOLE, JA KLEMPERER, SL TI SEISMIC EVIDENCE FOR A LOWER-CRUSTAL DETACHMENT BENEATH SAN-FRANCISCO BAY, CALIFORNIA SO SCIENCE LA English DT Article ID LOMA-PRIETA EARTHQUAKE; ANDREAS FAULT SYSTEM; CONTINENTAL-MARGIN; VELOCITY STRUCTURE; COAST RANGES; GREAT VALLEY; EVOLUTION; EDGE; TRANSFORM; INVERSION AB Results from the San Francisco Bay area seismic imaging experiment (BASIX) reveal the presence of a prominent lower crustal reflector at a depth of similar to 15 kilometers beneath San Francisco and San Pablo bays. Velocity analyses indicate that this reflector marks the base of Franciscan assemblage rocks and the top of a mafic lower crust. Because this compositional contrast would imply a strong theological contrast, this interface may correspond to a lower crustal detachment surface. If so, it may represent a subhorizontal segment of the North America and Pacific plate boundary proposed by earlier thermomechanical and geological models. C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. PENN STATE UNIV,DEPT GEOSCI,UNIVERSITY PK,PA 16802. UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305. RP BROCHER, TM (reprint author), US GEOL SURVEY,MAIL STOP 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Holbrook, W. Steven/G-9800-2011; Klemperer, Simon/A-5919-2012; OI Holbrook, W. Steven/0000-0003-0065-8841; Brocher, Thomas/0000-0002-9740-839X; Klemperer, Simon/0000-0001-7050-1829 NR 41 TC 70 Z9 70 U1 0 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 2 PY 1994 VL 265 IS 5177 BP 1436 EP 1439 DI 10.1126/science.265.5177.1436 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PE733 UT WOS:A1994PE73300045 PM 17833818 ER PT J AU KONNERT, JA EVANS, HT MCGEE, JJ ERICKSEN, GE AF KONNERT, JA EVANS, HT MCGEE, JJ ERICKSEN, GE TI MINERALOGICAL STUDIES OF THE NITRATE DEPOSITS OF CHILE .7. 2 NEW SALINE MINERALS WITH THE COMPOSITION K6(NA,K)4NA6MG10(XO4)12(IO3)12.12H2O-FUENZALIDAITE (X=S) AND CARLOSRUIZITE (X=SE) SO AMERICAN MINERALOGIST LA English DT Article AB Two new isostructural saline minerals from the nitrate deposits of northern Chile have the composition K6(Na,K)4Na6Mg10(XO4)12(IO3)12 . 12H2O: fuenzalidaite (FNZ, X = S) and carlosruizite (CLR, X = Se,S,Cr). They are trigonal, P3BARcl; for FNZ a = 9.4643(4), c = 27.336(6) angstrom; for CLR a = 9.5901(8), c = 27.56(2) angstrom. The crystals form thin hexagonal plates on {0001} up to 0.2 mm across, beveled at the edges by {101BAR2}. The crystals are transparent and pale yellow; optics are uniaxial negative with omega = 1.622(5), epsilon = 1.615(5) (FNZ), and omega = 1.655(3), epsilon = 1.642(1) (CLR). The crystal structure (R(w) = 0.043 for FNZ, 0.053 for CLR) consists of two complex slabs normal to the c axis, each having a double layer of iodate groups (IO3), bounded at the top and bottom by layers of SO4 or SeO4 groups. The strongest X-ray powder lines [d, (I, hkl)] for FNZ are 13.67 (50,002), 7.05 (40,102), 3.927 (100,202), 3.023 (41,212,117), 2.681 (33,302); for CLR, 13.75 (30,002), 7.10 (20,102), 3.561 (100,204), 3.082 (32,206), 3.058 (39,212,117), 2.715 (39,302). RP KONNERT, JA (reprint author), US GEOL SURVEY,NATL CTR 959,RESTON,VA 22092, USA. NR 7 TC 11 Z9 11 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 SEP-OCT PY 1994 VL 79 IS 9-10 BP 1003 EP 1008 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PM159 UT WOS:A1994PM15900022 ER PT J AU REDDY, MM CLAASSEN, HC RUTHERFORD, DW CHIOU, CT AF REDDY, MM CLAASSEN, HC RUTHERFORD, DW CHIOU, CT TI WELDED TUFF POROSITY CHARACTERIZATION USING MERCURY INTRUSION, NITROGEN AND ETHYLENE-GLYCOL MONOETHYL ETHER SORPTION AND EPIFLUORESCENCE MICROSCOPY SO APPLIED GEOCHEMISTRY LA English DT Article AB Porosity of welded tuff from Snowshoe Mountain, Colorado, was characterized by mercury intrusion porosimetry (MIP), nitrogen sorption porosimetry, ethylene glycol monoethyl ether (EGME) gas phase sorption and epifluorescence optical microscopy. Crushed tuff of two particle-size fractions (1-0.3 mm and less than 0.212 mm), sawed sections of whole rock and crushed tuff that had been reacted with 0.1 N hydrochloric acid were examined. Average MIP pore diameter values were in the range of 0.01-0.02 mu m. Intrusion volume was greatest for tuff reacted with 0.1 N hydrochloric acid and least for sawed tuff. Cut rock had the smallest porosity (4.72%) and crushed tuff reacted in hydrochloric acid had the largest porosity (6.56%). Mean pore diameters from nitrogen sorption measurements were 0.0075-0.0187 mu m. Nitrogen adsorption pore volumes (from 0.005 to 0.013 cm(3)/g) and porosity values (from 1.34 to 3.21%) were less than the corresponding values obtained by MIP. More than half of the total tuff pore volume was associated with pore diameters <0.05 mu m. Vapor sorption of EGME demonstrated that tuff pores contain a clay-like material. Epifluorescence microscopy indicated that connected porosity is heterogeneously distributed within the tuff matrix; mineral grains had little porosity. Tuff porosity may have important consequences for contaminant disposal in this host rock. RP REDDY, MM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,3215 MARINE ST,BOULDER,CO 80303, USA. NR 0 TC 5 Z9 5 U1 0 U2 3 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 1994 VL 9 IS 5 BP 491 EP & DI 10.1016/0883-2927(94)90012-4 PG 0 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PE162 UT WOS:A1994PE16200002 ER PT J AU LAMBERTY, A LAPITAJS, G VANNEVEL, L GOTZ, A MOODY, JR ERDMANN, DE DEBIEVRE, P AF LAMBERTY, A LAPITAJS, G VANNEVEL, L GOTZ, A MOODY, JR ERDMANN, DE DEBIEVRE, P TI THE IRMM INTERNATIONAL MEASUREMENT EVALUATION PROGRAM (IMEP) - IMEP-3-TRACE ELEMENTS IN SYNTHETIC AND NATURAL-WATER SO BIOLOGICAL TRACE ELEMENT RESEARCH LA English DT Article; Proceedings Paper CT 1993 International Conference on Nuclear Analytical Methods in the Life Sciences (NAMLS-93) CY 1993 CL UNIV AGR, PRAGUE, CZECH REPUBLIC SP Ioannus Marcus Marci Spectroscop Soc, Univ Agr, Prague, Commiss European Communities, Joint Res Ctr, Environm Inst, ISPRA, Inter Atom Energy Agcy HO UNIV AGR DE INTERNATIONAL MEASUREMENT EVALUATION PROGRAM (IMEP); CERTIFICATION BY ISOTOPE-SPECIFIC METHODS; ISOTOPE DILUTION AB The aim of the IRMM-International Measurement Evaluation Program (IMEP) is to test out a possible realization of international measurement comparability for field laboratories through traceability of their measurements to the SI Unit for amount of substance: the mole. In IMEP-3, 10 different trace elements, B, Ca, Cd, Cu, Fe, K, Li, Pb, Rb, and Zn, were determined in a synthetic and a natural water by participating laboratories using their routine methods and graphically compared (in coded form) to certified values, established by IRMM and NIST using an isotope-specific method (Isotope Dilution Mass Spectrometry, Neutron Activation Analysis). The number of participants was 70; 64 laboratories have reported results. The results show a spread of more than 50% asymmetrically around the certified value. The Youden graphs allow evaluation of the overall performance of the laboratories in the IMEP-3 round. C1 UNIV SAARBRUCKEN,SAARBRUCKEN,GERMANY. UNIV ANTWERP,IRMM,ANTWERP,BELGIUM. NIST,GAITHERSBURG,MD 20899. US GEOL SURVEY,DENVER,CO 80225. RP LAMBERTY, A (reprint author), IRMM,B-2440 GEEL,BELGIUM. NR 3 TC 1 Z9 1 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07012 SN 0163-4984 J9 BIOL TRACE ELEM RES JI Biol. Trace Elem. Res. PD FAL PY 1994 VL 43-5 BP 571 EP 583 DI 10.1007/BF02917360 PG 13 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA PZ203 UT WOS:A1994PZ20300068 PM 7710875 ER PT J AU LINK, WA BARKER, RJ AF LINK, WA BARKER, RJ TI DENSITY-ESTIMATION USING THE TRAPPING WEB DESIGN - A GEOMETRIC ANALYSIS SO BIOMETRICS LA English DT Article DE CAPTURE RECAPTURE; FOURIER SERIES MODEL; POPULATION DENSITY ESTIMATION; SMALL MAMMALS; TRAPPING WEB DESIGN AB Population densities for small mammal and arthropod populations can be estimated using capture frequencies for a web of traps. Anderson et al. (1983, Ecology 64, 674-680) adapted the point transect methodology to the analysis of such data. This paper proposes a conceptually simple geometric analysis that avoids the need to estimate a point on a density function. The new analysis has the advantage of incorporating data from the outermost rings of traps, explaining large capture frequencies in these rings rather than truncating them from the analysis. C1 UNIV FLORIDA,DEPT WILDLIFE & RANGE SCI,FISH & WILDLIFE COOPERAT RES UNIT,GAINESVILLE,FL 32611. RP LINK, WA (reprint author), US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708, USA. NR 7 TC 11 Z9 11 U1 0 U2 7 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 1994 VL 50 IS 3 BP 733 EP 745 DI 10.2307/2532787 PG 13 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA PL748 UT WOS:A1994PL74800013 ER PT J AU BOWERMAN, WW KUBIAK, TJ HOLT, JB EVANS, DL ECKSTEIN, RG SINDELAR, CR BEST, DA KOZIE, KD AF BOWERMAN, WW KUBIAK, TJ HOLT, JB EVANS, DL ECKSTEIN, RG SINDELAR, CR BEST, DA KOZIE, KD TI OBSERVED ABNORMALITIES IN MANDIBLES OF NESTLING BALD EAGLES HALIAEETUS-LEUCOCEPHALUS SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID FISH-EATING BIRDS; LAKES FOOD-CHAINS; GREAT-LAKES; POLYCHLORINATED-BIPHENYLS; DEVELOPMENTAL TOXICANTS; REPRODUCTIVE OUTCOMES; RESIDUE LEVELS; CHICK-EMBRYOS; AQUATIC BIRDS; BIOMARKER C1 US FISH & WILDLIFE SERV,DIV ENVIRONM CONTAMINANTS,ARLINGTON,VA 22203. BUREAU WILDLIFE MGT,WISCONSIN DEPT NAT RESOURCES,RHINELANDER,WI 53186. RP BOWERMAN, WW (reprint author), MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,PESTICIDE RES CTR,DEPT FISHERIES & WILDLIFE,E LANSING,MI 48824, USA. NR 29 TC 30 Z9 32 U1 2 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 SEP PY 1994 VL 53 IS 3 BP 450 EP 457 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NV831 UT WOS:A1994NV83100019 PM 7919724 ER PT J AU KUNKEL, KE MECH, LD AF KUNKEL, KE MECH, LD TI WOLF AND BEAR PREDATION ON WHITE-TAILED DEER FAWNS IN NORTHEASTERN MINNESOTA SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID MOOSE CALF MORTALITY; HERD CASE-HISTORY; RED DEER; BODY-COMPOSITION; CERVUS-ELAPHUS; MATERNAL AGE; SURVIVAL; CARIBOU; BEHAVIOR; WINTER AB White-tailed deer (Odocoileus virginianus) fawn mortality was studied during the summers of 1989 and 1990 in northeastern Minnesota. Estimated pooled mortality rates for 21 radio-tagged fawns were 0.44 for the May-June, 0.13 for the July-October, and 0.51 for the May-October intervals. Predation accounted for all mortalities, with wolves (Canis lupus) responsible for 51% of them and black bears (Ui sus americanus) for 49%. Fawns from mothers >4 years old weighed more and survived better than fawns from young mothers, which weighed less. Of various related factors (doe age, doe mass, fawn mass, fawn birth date, and fawn blood serum urea nitrogen (SUN)), only SUN was significant between surviving and perishing fawns; fawns with low SUN survived significantly less. Fawn SUN may have been only an indirect indicator of a doe physical or behavioral factor that was more important to fawn survival. C1 UNIV MINNESOTA,DEPT FISHERIES & WILDLIFE,ST PAUL,MN 55108. US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. NR 91 TC 81 Z9 84 U1 0 U2 19 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 SEP PY 1994 VL 72 IS 9 BP 1557 EP 1565 DI 10.1139/z94-207 PG 9 WC Zoology SC Zoology GA QE435 UT WOS:A1994QE43500005 ER PT J AU MALLATT, J MCCALL, RD BAILEY, JF SEELYE, J AF MALLATT, J MCCALL, RD BAILEY, JF SEELYE, J TI EFFECTS OF LAMPRICIDES ON THE GILL ULTRASTRUCTURE OF LARVAL SEA LAMPREYS AND RAINBOW-TROUT FRY SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID PETROMYZON-MARINUS; MORPHOLOGY; RICHARDSON; FISH AB Larval lampreys (Petromyzon marinus) and rainbow trout fry (Oncorhynchus mykiss) were exposed to toxic solutions of the lampricidal chemicals TFM (3-trifluormethyl-4-nitrophenol) and Bayer 73 (5,2'-dichloro-4'-nitrosalicylanilide). Both species were exposed to their 9-h LC(100) for 9 h or until they were near death. The respiratory lamellae of the gills were then studied with transmission electron microscopy. In lampreys, damage was confined to presumed ion-uptake cells. Both lampricides produced similar changes in these cells: cell rounding, enlargement of mitochondrial profiles, vacuolization of the cytoplasm, and widening of the intercellular spaces. Bayer 73 caused a greater incidence of necrosis of ion-uptake cells than did TFM. Exposure to lethal TFM/Bayer-73 mixtures (containing 0.4-1.6% Bayer 73) affected lamprey gill lamellae in the same way as did Bayer 73. Unlike lamprey gills, trout gills were entirely unaltered by levels of the lampricides lethal to trout. These findings suggest that (i) disruption of ion-regulating cells contributes to the mortality of lampreys exposed to lampricides and to the high susceptibility of lampreys to TFM; (ii) the mechanisms of cytotoxicity of TFM and Bayer 73 are similar C1 UNIV IDAHO,CTR ELECTRON MICROSCOPY,MOSCOW,ID 83843. US FISH & WILDLIFE SERV,HAMMOND BAY BIOL STN,MILLERSBURG,MI 49759. RP MALLATT, J (reprint author), WASHINGTON STATE UNIV,DEPT ZOOL,PULLMAN,WA 99164, USA. NR 28 TC 8 Z9 8 U1 2 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 SEP PY 1994 VL 72 IS 9 BP 1653 EP 1664 DI 10.1139/z94-221 PG 12 WC Zoology SC Zoology GA QE435 UT WOS:A1994QE43500019 ER PT J AU SIMON, NS DEMAS, C DANGELO, W AF SIMON, NS DEMAS, C DANGELO, W TI GEOCHEMISTRY AND SOLID-PHASE ASSOCIATION OF CHROMIUM IN SEDIMENT FROM THE CALCASIEU RIVER AND ESTUARY, LOUISIANA, USA SO CHEMICAL GEOLOGY LA English DT Article ID CHEMICAL-FRACTIONS; POTOMAC RIVER; SOLUBILITY; HYDROXIDE; COPPER; WATERS; METALS; IRON AB Sediment samples were collected from the lower Calcasieu River and estuary, Louisiana, in a study of the release of metals from sediments to the overlying water column. Whole samples were characterized by analyses that included: (1) determination of total sediment ammonium concentrations; (2) determination of total sediment Cr, Mn and Fe concentrations; (3) extraction of sediment with hydrogen peroxide followed by dilute hydrochloric acid to obtain recoverable metals, including oxides; and (4) extraction of sediment with hydrogen peroxide plus pyrophosphate at a pH of 7-8 to recover organically-bound Cr but not metal oxides. Concentrations of Cr, Mn and Fe in sediment interstitial water were determined. The concentrations of Cr in interstitial water could not be predicted from total sediment concentrations of Cr. Degradation of organic matter appeared to be the mechanism that caused elevated Cr concentrations in the interstitial water. Concentrations of Cr in interstitial water were positively correlated with total concentrations of ammonium in sediment. Concentrations of Cr in interstitial water that exceeded water-column concentratiosn of Cr were found when the total concentrations of ammonium in sediment exceeded 1 mumol per gram wet weight. Concentrations of metals in interstitial water that are larger than metal concentrations in the water column create a potential for diffusive flux and metal enrichment of the overlying water column. C1 US GEOL SURVEY,DIV WATER RESOURCES,BATON ROUGE,LA 70896. US GEOL SURVEY,DIV GEOL,RESTON,VA 22092. RP SIMON, NS (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MAIL STOP 432,RESTON,VA 22092, USA. NR 25 TC 11 Z9 11 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 1 PY 1994 VL 116 IS 1-2 BP 123 EP 135 DI 10.1016/0009-2541(94)90161-9 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PF447 UT WOS:A1994PF44700008 ER PT J AU SLATER, CH SCHRECK, CB SWANSON, P AF SLATER, CH SCHRECK, CB SWANSON, P TI PLASMA PROFILES OF THE SEX STEROIDS AND GONADOTROPINS IN MATURING FEMALE SPRING CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY LA English DT Article DE SEX STEROIDS; GONADOTROPINS; SPRING CHINOOK SALMON; ONCORHYNCHUS TSHAWYTSCHA ID RAINBOW-TROUT; COHO SALMON; CHUM SALMON; 17-ALPHA,20-BETA-DIHYDROXY-4-PREGNEN-3-ONE LEVELS; REPRODUCTIVE-CYCLES; SPAWNING MIGRATION; OVARIAN FOLLICLES; SERUM LEVELS; BROWN TROUT; VITELLOGENIN AB Plasma testosterone concentrations were low through the spring acid early summer, concentrations began rising in late July and reached maximum levels by ovulation in September. Plasma concentrations of 11-ketotestosterone were low throughout sexual maturation until ovulation when a significant increase occurred. Plasma androstendione and 17 beta-estradiol concentrations were high throughout sexual maturation, and decreased significantly at ovulation. Plasma 17 alpha,20 beta -dihydroxy-4-pregnen-3-one concentrations were low throughout maturation, and increased significantly at ovulation. Plasma gonadotropin I concentrations paralleled those of estradiol and exceeded gonadotropin II levels prior to ovulation. Plasma concentrations of gonadotropin II were low throughout the spring and summer, increasing dramatically at ovulation. C1 US FISH & WILDLIFE SERV, SEATTLE, WA 98112 USA. UNIV WASHINGTON, SCH FISHERIES, SEATTLE, WA 98112 USA. NOAA, NATL MARINE FISHERIES SERV, NW FISHERIES SCI CTR, SEATTLE, WA 98112 USA. RP SLATER, CH (reprint author), OREGON STATE UNIV, DEPT FISHERIES & WILDLIFE, OREGON COOPERAT FISHERY RES UNIT, 104 NASH HALL, CORVALLIS, OR 97331 USA. NR 34 TC 88 Z9 90 U1 4 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1095-6433 EI 1531-4332 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Mol. Integr. Physiol. PD SEP PY 1994 VL 109 IS 1 BP 167 EP 175 DI 10.1016/0300-9629(94)90323-9 PG 9 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA NZ742 UT WOS:A1994NZ74200017 ER PT J AU ENGEMAN, RM SUGIHARA, RT PANK, LF DUSENBERRY, WE AF ENGEMAN, RM SUGIHARA, RT PANK, LF DUSENBERRY, WE TI A COMPARISON OF PLOTLESS DENSITY ESTIMATORS USING MONTE-CARLO SIMULATION SO ECOLOGY LA English DT Article DE DENSITY ESTIMATION; DISTANCE METHODS; PLOTLESS METHODS; SPATIAL PATTERN ID DISTANCE AB We conducted an extensive simulation study to compare the performance of a large group of plotless density estimators (PDEs) to obtain clarification of their relative performance in a diversity of sampling situations. The PDEs studied included well-known ones from the literature plus some extensions and modifications introduced here. The simulations cover 96 combinations of 6 spatial patterns, 4 sample sizes, and 4 population densities. We made comparisons within classes of similar estimators, and we indicate the best-performing PDEs out of the complete set studied. Over all spatial patterns, the angle-order estimator with measurements to the third-closest individual in each quadrant had the lowest relative root-mean-squared error (RRMSE), followed by the same estimation method with measurements to the second closest individual in each quadrant. Also performing well were the variable area transect, the ordered distance estimator using the third closest individual, and an extension of the Kendall-Moran estimator that searches for the second nearest neighbor and pools search areas from all sample points. Opinions and recommendations are given as to which PDEs perform well enough and are practical enough to deserve strong consideration for use in the field. C1 USDA,ANIM & PLANT HLTH INSPECT SERV,DENVER WILDLIFE RES CTR,HAWAII FIELD STN,HILO,HI 96721. US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. RP ENGEMAN, RM (reprint author), USDA,ANIM & PLANT HLTH INSPECT SERV,POB 25266,DENVER,CO 80225, USA. NR 28 TC 82 Z9 85 U1 1 U2 19 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD SEP PY 1994 VL 75 IS 6 BP 1769 EP 1779 DI 10.2307/1939636 PG 11 WC Ecology SC Environmental Sciences & Ecology GA PE267 UT WOS:A1994PE26700024 ER PT J AU ANDERSON, DR BURNHAM, KP WHITE, GC AF ANDERSON, DR BURNHAM, KP WHITE, GC TI AIC MODEL SELECTION IN OVERDISPERSED CAPTURE-RECAPTURE DATA SO ECOLOGY LA English DT Article DE AIC; AKAIKE; CAPTURE RECAPTURE; CORMACK JOLLY SEBER MODEL; EXTRA-BINOMIAL VARIATION; KULLBACK LEIBLER DISCREPANCY; MODEL SELECTION; OVERDISPERSION ID EXTRA-BINOMIAL VARIATION; INFORMATION CRITERION; LINEAR-MODELS; LIKELIHOOD; POPULATION; REGRESSION; CHOICE; TIME AB Selection of a proper model as a basis for statistical inference from capture-recapture data is critical. This is especially so when using open models in the analysis of multiple, interrelated data sets (e.g., males and females, with 2-3 age classes, over 3-5 areas and 10-15 yr). The most general model considered for such data sets might contain 1000 survival and recapture parameters. This paper presents numerical results on three information-theoretic methods for model selection when the data are overdispersed (i.e., a lack of independence so that extra-binomial variation occurs). Akaike's information criterion (AIC), a second-order adjustment to AIC for bias (AIC(c)), and a dimension-consistent criterion (CAIC) were modified using an empirical estimate of the average overdispersion, based on quasi-likelihood theory. Quality of model selection was evaluated based on the Euclidian distance between standardized <(theta)over cap> and theta (parameter theta is vector valued); this quantity (a type of residual sum of squares, hence denoted as RSS) is a combination of squared bias and variance. Five results seem to be of general interest for these product-multinomial models. First, when there was overdispersion the most direct estimator of the variance inflation factor was positively biased and the relative bias increased with the amount of overdispersion. Second, AIC and AIC(c), unadjusted for overdispersion using quasi-likelihood theory, performed poorly in selecting a model with a small RSS value when the data were overdispersed (i.e., overfitted models were selected when compared to the model with the minimum RRS value). Third, the information-theoretic criteria, adjusted for overdispersion, performed well, selected parismonious models, and had a good balance between under- and overfitting the data. Fourth, generally, the dimension-consistent criterion selected models with fewer parameters than the other criteria, had smaller RSS values, but clearly was in error by underfitting when compared with the model with the minimum RSS value. Fifth, even if the true model structure (but not the actual parameter values in the model) is known, that true model, when fitted to the data (by parameter estimation) is a relatively poor basis for statistical inference when that true model includes several, let alone many, estimated parameters that are not significantly different from O. C1 COLORADO STATE UNIV,DEPT FISHERY & WILDLIFE BIOL,FT COLLINS,CO 80523. RP ANDERSON, DR (reprint author), DEPT INTERIOR,US FISH & WILDLIFE SERV,COLORADO COOPERAT FISH & WILDLIFE RES UNIT,FT COLLINS,CO 80523, USA. RI Piper, Walter/B-7908-2009 NR 49 TC 402 Z9 414 U1 1 U2 59 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD SEP PY 1994 VL 75 IS 6 BP 1780 EP 1793 DI 10.2307/1939637 PG 14 WC Ecology SC Environmental Sciences & Ecology GA PE267 UT WOS:A1994PE26700025 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 UNITED-STATES MIDCONTINENT SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID LEAD-ZINC MINERALIZATION; EXTENSIVE EPIGENETIC DOLOMITES; THERMOCHEMICAL SULFATE REDUCTION; INCLUSION GAS CHEMISTRY; SOUTHEAST MISSOURI; VIBURNUM-TREND; FLUID-INCLUSION; MULTIPLE FLUIDS; GENETIC-IMPLICATIONS; BARITE DEPOSITS AB The Ozark region of the U.S. midcontinent is host to a number of Mississippi Valley-type districts, including the world-class Viburnum Trend, Old Lead Belt, and Tri-State districts and the smaller Southeast Missouri barite, Northern Arkansas, and Central Missouri districts. There is increasing evidence that the Ozark Mississippi Valley-type districts formed locally within a large, interconnected hydrothermal system that also produced broad fringing areas of trace mineralization, extensive subtle hydrothermal alteration, broad thermal anomalies, and regional deposition of hydrothermal dolomite cement. The fluid drive was provided by gravity flow accompanying uplift of foreland thrust belts during the Late Pennsylvanian to Early Permian Ouachita orogeny. In this study, we use chemical speciation and reaction path calculations, based on quantitative chemical analyses of fluid inclusions, to constrain likely hydrothermal brine compositions and to determine which precipitation mechanisms are consistent with the hydrothermal mineral assemblages observed regionally and locally within each Mississippi Valley-type district in the Ozark region. Deposition of the regional hydrothermal dolomite cement with trace sulfides likely occurred in response to near-isothermal effervescence of CO2 from basinal brines as they migrated to shallower crustal levels and lower confining pressures. In contrast, our calculations indicate that no one depositional process can reproduce the mineral assemblages and proportions of minerals observed in each Ozark ore district; rather, individual districts require specific depositional mechanisms that reflect the local host-rock composition, structural setting, and hydrology. Both the Northern Arkansas and Tri-State districts are localized by normal faults that likely allowed brines to rise from deeper Cambrian-Ordovician dolostone aquifers into shallower carbonate sequences dominated by limestones. In the Northern Arkansas district, jasperoid preferentially replaced limestones in the mixed dolostone-limestone sedimentary packages. Modeling results indicate that the ore and alteration assemblages in the Tri-State and Northern Arkansas districts resulted from the flow of initially dolomite-saturated brines into cooler limestones. Adjacent to fluid conduits where water/rock ratios were the highest, the limestone was replaced by dolomite. As the fluids moved outward into cooler limestone, jasperoid and sulfide replaced limestone. Isothermal boiling of the ore fluids may have produced open-space filling of hydrothermal dolomite with minor sulfides in breccia and fault zones. Local mixing of the regional brine with locally derived sulfur undoubtedly played a role in the development of sulfide-rich ore runs. Sulfide ores of the Central Missouri district are largely open-space filling of sphalerite plus minor galena in dolostone karst features localized along a broad anticline. Hydrothermal solution collapse during ore deposition was a minor process, indicating dolomite was slightly undersaturated during ore deposition. No silicification and only minor hydrothermal dolomite is present in the ore deposits. The reaction path that best explains the features of the Central Missouri sulfide deposits is the near-isothermal mixing of two dolomite-saturated fluids with different H2S and metal contents. Paleokarst features may have allowed the regional brine to rise stratigraphically and mix with locally derived, H2S-rich fluids. 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 80 TC 71 Z9 78 U1 7 U2 29 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 SEP-OCT PY 1994 VL 89 IS 6 BP 1361 EP 1383 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PV036 UT WOS:A1994PV03600009 ER PT J AU YOUD, TL KEEFER, DK AF YOUD, TL KEEFER, DK TI LIQUEFACTION DURING THE 1977 SAN-JUAN PROVINCE, ARGENTINA EARTHQUAKE (M(S)=7.4) SO ENGINEERING GEOLOGY LA English DT Article AB Liquefaction effects generated by the 1977 San Juan Province, Argentina, earthquake (M(s) = 7.4) are described. The larger and more abundant effects were concentrated in the 60-km long band of the lowlands in the Valle del Bermejo and in an equally long band along the Rio San Juan in the Valle de Tulum. Fissures in the Valle del Bermejo were up to several hundred meters long and up to several meters wide. Sand deposits, from boils that erupted through the fissures, covered areas up to tens of square meters. Fissures generally parallelled nearby stream channels. Because the Valle del Bermejo is undeveloped, these large features caused no damage. Liquefaction in the Valle del Tulum caused important or unusual damage at several localities, including the following five sites: (1) At the Barrio Justo P. Castro, a subdivision of Caucete, liquefaction of subsurface sediments decoupled overlying, unliquefied stiff sediments, producing a form of ground failure called ''ground oscillation''. The associated differential ground movements pulled apart houses and pavements in extension, while shearing curbs and buckling canal linings in compression at the same locality. (2) At the Escuela Normal, in Caucete, the roof of a 30-m long single-story classroom building shifted westward relative to the foundation. That displacement fractured and tilted columns supporting the roof. The foundation was fractured at several places, leaving open cracks, as wide as 15 mm. The cumulative width of the open cracks was 48 mm, an amount roughly equivalent to the 63 mm of offset between the roof and foundation at the east end of the building. The ground and foundation beneath the building extended (or spread) laterally opening cracks and lengthening the foundation while the roof remained in place. (3) The most spectacular damage to structures at the community of San Martin was the tilting of a 6-m high water tower and the toppling of a nearby pump house into a 1-m deep crater. Similarly, a small crater developed beneath a hand-pump in an open area and a large, 6-m diameter crater formed nearby. The following sequence of events created the craters and toppled the pump structures: During the earthquake, ground shaking generated excess pore pressures which were dissipated by upward flow of groundwater. Free drainage was restricted by an impermeable plastic-silt layer. Water apparently accumulated below the plastic-silt layer and then burst to the surface through several holes and cracks, including holes around well casings. (4) At the San Isidro winery, nine storage tanks tilted 2 to 5-degrees. Five reinforced-concrete tanks were dismantled but four steel tanks were repaired by placing new footings and jacking the structures into an upright position. (5) At Escuela J.J. Pasos, differential settlement beneath buildings fractured several columns and walls. The largest settlements were about 60 mm and the maximum settlement of footings supporting columns was about 40 mm. In spite of the damage, the buildings were in no danger of collapse. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP YOUD, TL (reprint author), BRIGHAM YOUNG UNIV,PROVO,UT 84602, USA. NR 0 TC 8 Z9 8 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0013-7952 J9 ENG GEOL JI Eng. Geol. PD SEP PY 1994 VL 37 IS 3-4 BP 211 EP 233 DI 10.1016/0013-7952(94)90057-4 PG 23 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA PK991 UT WOS:A1994PK99100004 ER PT J AU HARKEY, GA LYDY, MJ KUKKONEN, J LANDRUM, PF AF HARKEY, GA LYDY, MJ KUKKONEN, J LANDRUM, PF TI FEEDING SELECTIVITY AND ASSIMILATION OF PAH AND PCB IN DIPOREIA SPP SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE ASSIMILATION EFFICIENCY; BIOAVAILABILITY; SEDIMENT; DIPOREIA SPP; ORGANIC CARBON ID POLYCYCLIC AROMATIC-HYDROCARBONS; AMPHIPOD PONTOPOREIA-HOYI; GUT CONTENTS; SEDIMENT; BIOAVAILABILITY; TOXICOKINETICS; EFFICIENCY AB A series of experiments were conducted to estimate assimilation efficiencies of two hydrophobic organic contaminants and the influence of particle sizes on the selective sediment ingester, Diporeia spp. Florissant soil was divided into particle-size fractions consisting of 0 to 63 mum, 0 to 20 mum, and 20 to 63 mum and dosed with radiolabeled 2,2,4,4,5,5'-hexachlorobiphenyl (HCBP) and/or benzo[a]pyrene (BaP) to which animals were exposed for individual assays. At the end of timed exposure intervals, individual Diporeia and any fecal pellets they produced were removed from the sediment and analyzed for contaminant content. Assimilation efficiency was estimated via a selectivity index based on organic carbon. Assimilation efficiency of BaP (5.6-32.7%) was comparable to previous studies. However, HCBP did not correlate with organic carbon over a range of particle sizes. Accumulation of both contaminants was greatest when animals were exposed to the 20- to 63-mum size fraction, suggesting that Diporeia selectively fed within this particle-size range. Accumulation of HCBP was consistently greater than BaP in all dual-labeled assays, suggesting a greater bioavailability of the PCB to Diporeia. Sediment analysis indicated that BaP and HCBP were associated with different particle-size fractions possessing different amounts of organic carbon, with BaP having the greater tendency to associate with TOC. C1 GREAT LAKES ENVIRONM RES LAB,2200 COMMONWEALTH BLVD,ANN ARBOR,MI 48105. CLEMSON UNIV,INST WILDLIFE & ENVIRONM TOXICOL,PENDLETON,SC 29670. US GEOL SURVEY,DIV WATER RESOURCES,INDIANAPOLIS,IN 46278. UNIV JOENSUU,DEPT BIOL,SF-80101 JOENSUU,FINLAND. NR 34 TC 71 Z9 71 U1 0 U2 6 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 SEP PY 1994 VL 13 IS 9 BP 1445 EP 1455 DI 10.1897/1552-8618(1994)13[1445:FSAAOP]2.0.CO;2 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA PE170 UT WOS:A1994PE17000008 ER PT J AU SLACK, JF STEVENS, BPJ AF SLACK, JF STEVENS, BPJ TI CLASTIC METASEDIMENTS OF THE EARLY PROTEROZOIC BROKEN-HILL GROUP, NEW-SOUTH-WALES, AUSTRALIA - GEOCHEMISTRY, PROVENANCE, AND METALLOGENIC SIGNIFICANCE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID RARE-EARTH ELEMENT; META-SEDIMENTARY ROCKS; LACHLAN FOLD BELT; A-TYPE GRANITES; WILLYAMA SUPERGROUP; SOUTHEASTERN AUSTRALIA; SUPRACRUSTAL ROCKS; NORTHERN-TERRITORY; CRUSTAL EVOLUTION; FELSIC GNEISSES AB Whole-rock analyses of samples of pelite, psammite, and psammopelite from the Early Proterozoic Broken Hill Group (Willyama Supergroup) in the Broken Hill Block, New South Wales, Australia, reveal distinctive geochemical signatures. Major-element data show high Al2O3 and K2O, low MgO and Na2O, and relatively high Fe2O3T/MgO ratios, compared to average Early Proterozoic elastic metasediments. High field strength elements (HFSE) are especially abundant, including Nb (most 15-27 ppm), Ta (most 1.0-2.2 ppm), Th (17-36 ppm). Hf (4-15 ppm), and Zr (most 170-400 ppm); Y (33-74 ppm) is also high. Concentrations of ferromagnesian elements are generally low (Sc = <20 ppm, Ni = less than or equal to 62 ppm, Co = <26 ppm; Cr = most <100 ppm). Data for rare earth elements (REEs) show high abundances of light REEs (La-CN = 116-250X chondrite; La-CN = 437 in one sample), high La-CN/Yb-CN ratios (5.6-13.9), and large negative Eu anomalies (Eu/Eu* = 0.32-0.57). The geochemical data indicate derivation of the metasedimentary rocks of the Broken Hill Group by the erosion mainly of felsic igneous (or meta-igneous) rocks. High concentrations of HFSE, Y, and REEs in the metasediments suggest a provenance dominanted by anorogenic granites and(or) rhyolites, including those with A-type chemistry. Likely sources of the metasediments were the rhyolitic to rhyodacitic protoliths of local quartz + feldspar +/- biotite +/- garnet gneisses (e.g., Potosi-type gneiss) that occur within the lower part of the Willyama Supergroup, or chemically similar basement rocks in the region; alternative sources may have included Early Proterozoic anorogenic granites and(or) rhyolites in the Mount Isa and(or) Pine Creek Blocks of northern Australia. or in the Gawler craton of South Australia. Metallogenic considerations suggest that the metasediments of the Broken Hill Block formed enriched source rocks during the generation of pegmatite-hosted deposits and concentrations of La, Ce, Nb, Ta, Th, and Sn in the region. Li, Be, B, W, and U in pegmatite minerals of the district may have been acquired during granulite-facies metamorphism of the local metasediments. C1 GEOL SURVEY NEW S WALES, BROKEN HILL, NSW 2880, AUSTRALIA. RP US GEOL SURVEY, NATL CTR, MS 954, RESTON, VA 22092 USA. NR 96 TC 47 Z9 50 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 SEP PY 1994 VL 58 IS 17 BP 3633 EP 3652 DI 10.1016/0016-7037(94)90155-4 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PG266 UT WOS:A1994PG26600007 ER PT J AU OBRADOVIC, J HEIN, JR DJURDJEVIC, J AF OBRADOVIC, J HEIN, JR DJURDJEVIC, J TI DIAGENESIS OF DIATOMITE FROM THE KOLUBARA COAL BASIN, BAROSEVAC, SERBIA SO GEOLOGICAL JOURNAL LA English DT Article DE DIATOMITE; OPAL-A; DIAGENESIS; COAL DEPOSITS; KOLUBARA BASIN ID SILICA; OPAL AB Diatomite associated with the Kolubara Coal Basin was studied to better understand early stage silica diagenesis of shallow water deposits. The Kolubara Basin consists of Neogene siliciclastic rocks, diatomite, marlstone and rare carbonates. Palaeozoic metamorphic and Mesozoic sedimentary and igneous basement rocks are transgressively overlain by Upper Miocene sandstone, siltstone, shale and mudstone. This Upper Miocene section is transgressively overlain by the Pontian section, which contains diatomite and coal beds. White and grey diatomite forms beds 0.7-2.2 m thick that are continuous over an area of about 2 km2. Siliceous rocks vary in composition from diatomite (81-89 per cent SiO2) to diatom-bearing shale (58-60 per cent SiO2). Siliceous deposits are laminated in places, with the laminae defined by variations in clay minerals, organic matter and diatoms. Diatomite shows only incipient diagenesis characterized by the fragmentation of diatom frustules, the minor to moderate corrosion of frustules and the formation of minor amounts of opal-A' (X-ray amorphous inorganic opal) cement. The low degree of diagenesis results from the young age of the deposits, low burial temperatures and possibly also from the presence of abundant organic matter and the dissolution of kaolinite. The presence of only weak diagenesis is also reflected by the characteristically poor consolidation of the rocks and low rank of the associated coal. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP OBRADOVIC, J (reprint author), UNIV BELGRADE,FAC MIN & GEOL,DJUSINA 7,BELGRADE 11000,YUGOSLAVIA. NR 21 TC 1 Z9 1 U1 1 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0072-1050 J9 GEOL J JI Geol. J. PD SEP PY 1994 VL 29 IS 3 BP 209 EP 217 PG 9 WC Geosciences, Multidisciplinary SC Geology GA PL100 UT WOS:A1994PL10000002 ER PT J AU GEIST, EL VALLIER, TL SCHOLL, DW AF GEIST, EL VALLIER, TL SCHOLL, DW TI ORIGIN, TRANSPORT, AND EMPLACEMENT OF AN EXOTIC ISLAND-ARC TERRANE EXPOSED IN EASTERN KAMCHATKA, RUSSIA SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Review ID ANADYR-KORYAK REGION; BERING SEA REGION; NORTHEAST ASIA; PALINSPASTIC RECONSTRUCTIONS; KARAGINSKIY-ISLAND; PALEOMAGNETIC DATA; PLATE-TECTONICS; FORE-ARC; PENINSULA; EVOLUTION AB The regional stratigraphy of eastern Kamchatka includes an exotic, Early-Late Cretaceous ophiolite and Late Cretaceous island-are volcanic sequence. Integrating the existing geologic and geophysical data, we examine the origin, transport, emplacement, and postemplacement deformation of the island-are terrane, which is named the Olyutorsky island are. Results from several paleomagnetic studies consistently indicate that the island-are terrane originated >1000 km to the south of where it is presently exposed. Although the formative paleolatitudes of the island-are rocks approximately correspond to the location of the Izanagi-Farallon subduction zone, the age of the volcanic rocks postdates the cessation of Izanagi-Farallon convergence, thus indicating that an unnamed plate or back-are basin existed in the northwest Pacific during Late Cretaceous time. We examine two possible models for northward transport of the island are terrane to Kamchatka: (1) intra-oceanic transport with the Pacific or Kula plates and (2) coastwise translation of the island-are terrane after accretion to the Eurasian margin far to the south of Kamchatka. For both models, the dominant Eocene and Miocene deformation ages observed in eastern Kamchatka are used as two possible age limits for the cessation of northward transport. Although the observed paleolatitudes from paleomagnetic data correspond best with the intra-oceanic transport model, the provenance of the Paleogene ''transport'' stratigraphy indicates a nearshore sediment supply. Our preferred interpretation is that the island-are terrane (1) accreted onto the Eurasian margin concurrent with cessation of island-are volcanism (Maastrichtian-Danian) and (2) underwent northward coastwise translation along a major strike-slip fault zone ending by middle-late Eocene time (43-50 Ma). It is unclear whether the ophiolite was exposed during are-continent collision or whether the ophiolite was obducted onto the island are prior to collision. A consequence of either intra-oceanic transport or coastwise translation is that an open corridor between the western terminus of the Aleutian Are and Kamchatka must have existed until middle to late Eocene time. Spreading within the Komandorsky Basin, subduction of seamounts, and collision of the Aleutian Are with Kamchatka are proposed to have instigated the second Miocene phase of deformation, which uplifted and reexposed the island-are terrane. RP GEIST, EL (reprint author), US GEOL SURVEY,MS 999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 115 TC 33 Z9 33 U1 1 U2 5 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 1994 VL 106 IS 9 BP 1182 EP 1194 DI 10.1130/0016-7606(1994)106<1182:OTAEOA>2.3.CO;2 PG 13 WC Geosciences, Multidisciplinary SC Geology GA PE289 UT WOS:A1994PE28900007 ER PT J AU RENNE, PR DEINO, AL WALTER, RC TURRIN, BD SWISHER, CC BECKER, TA CURTIS, GH SHARP, WD JAOUNI, AR AF RENNE, PR DEINO, AL WALTER, RC TURRIN, BD SWISHER, CC BECKER, TA CURTIS, GH SHARP, WD JAOUNI, AR TI INTERCALIBRATION OF ASTRONOMICAL AND RADIOISOTOPIC TIME SO GEOLOGY LA English DT Article ID BRUNHES-MATUYAMA; TRIASSIC BOUNDARY; SIBERIAN TRAPS; CALIBRATION; SCALE; AGE; KENYA; TUFF; TIMESCALE; REVERSAL AB The Ar-40/Ar-39 radioisotopic dating technique is one of the most precise and versatile methods available for dating events in Earth's history, but the accuracy of this method is limited by the accuracy with which the ages of neutron-fluence monitors (dating standards) are known. Calibrating the ages of standards by conventional means has proved difficult and contentious. The emerging astronomically calibrated geomagnetic polarity time scale (APTS) offers a means to calibrate the ages of Ar-40/Ar-39 dating standards that is independent of absolute isotopic abundance measurements. Seven published Ar-40/Ar-39 dates for polarity transitions, nominally ranging from 0.78 to 3.40 Ma, are based on the Fish Canyon sanidine standard and can be compared with APTS predictions. Solving the Ar-40/Ar-39 age equation for the age of the Fish Canyon sanidine that produces coincidence with the APTS age for each of these seven reversals yields mutually indistinguishable estimates ranging from 27.78 to 28.09 Ma, with an inverse variance-weighted mean of 27.95 +/- 0.18 Ma. Normalized residuals are minimized at an age of 27.92 Ma, indicating the robustness of the solution. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP RENNE, PR (reprint author), BERKELEY GEOCHRONOL CTR,INST HUMAN ORIGINS,2453 RIDGE RD,BERKELEY,CA 94709, USA. NR 29 TC 207 Z9 210 U1 3 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 SEP PY 1994 VL 22 IS 9 BP 783 EP 786 DI 10.1130/0091-7613(1994)022<0783:IOAART>2.3.CO;2 PG 4 WC Geology SC Geology GA PE292 UT WOS:A1994PE29200004 ER PT J AU FLEMING, RF AF FLEMING, RF TI CRETACEOUS POLLEN IN PLIOCENE ROCKS - IMPLICATIONS FOR PLIOCENE CLIMATE IN THE SOUTHWESTERN UNITED-STATES SO GEOLOGY LA English DT Article ID COLORADO PLATEAU; CALIFORNIA; UPLIFT; BASIN; HISTORY; REGION; RECORD AB Pliocene rocks of the Imperial and Palm Spring Formations in southern California contain reworked Cretaceous pollen that helps determine the timing of erosion of Cretaceous rocks on the Colorado Plateau. The stratigraphic distribution of reworked pollen in the Imperial and Palm Spring Formations suggests that erosion of Cretaceous rocks in the southern part of the Colorado Plateau began by 4.5 Ma. Erosion of Cretaceous rocks in the northern part of the plateau began at 3.9 Ma. This erosional history indicates that rapid and extensive erosion of the Colorado Plateau occurred during the Pliocene and supports the hypothesis that much of the Grand Canyon was cut during the Pliocene, rather than earlier in the Tertiary. Rapid erosion and transport from the Colorado Plateau require the climate in that region during the Pliocene to have been significantly wetter than it is today. RP FLEMING, RF (reprint author), US GEOL SURVEY,DENVER,CO 80225, USA. NR 34 TC 14 Z9 14 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 SEP PY 1994 VL 22 IS 9 BP 787 EP 790 DI 10.1130/0091-7613(1994)022<0787:CPIPRI>2.3.CO;2 PG 4 WC Geology SC Geology GA PE292 UT WOS:A1994PE29200005 ER PT J AU ISTOK, JD RAUTMAN, CA FLINT, LE FLINT, AL AF ISTOK, JD RAUTMAN, CA FLINT, LE FLINT, AL TI SPATIAL VARIABILITY IN HYDROLOGIC PROPERTIES OF A VOLCANIC TUFF SO GROUND WATER LA English DT Article ID SOIL AB Spatial variability of hydrologic properties was quantified for a nonwelded-to-welded ash flow tuff at Yucca Mountain, Nevada, the potential site of a high-level, nuclear waste repository. Bulk density, porosity, saturated hydraulic conductivity, and sorptivity were measured on core specimens collected from outcrops on a grid that extended vertically through the entire unit thickness and horizontally 1.3 km in the direction of ash transport from the volcanic vent, A strong, geologically determined (deterministic) vertical trend in properties was apparent that correlated with visual trends in degree of welding observed in the outcrop. The trend was accurately described by simple regression models based on stratigraphic elevation (vertical distance from the base of the unit divided by unit thickness). No significant horizontal trends in properties were detected along the length of the transect. The validity of the developed model was tested by comparing model predictions with measured porosity values from additional outcrop sections and boreholes that extended 3000 m north, 1500 m northeast, and 6000 m south of the study area. The model accurately described vertical porosity variations except for locations very close to the source caldera, where the model underpredicted porosity in the upper half of the section. The presence of deterministic geologic trends, such as those demonstrated for an ash flow unit in this study, can simplify the collection of site characterization data and the development of site-scale models. C1 SANDIA NATL LABS,DEPT GEOSCI ASSESSMENT & VALIDAT,ALBUQUERQUE,NM 87185. US GEOL SURVEY,HYDROL RES FACIL,MERCURY,NV 89023. RAYTHEON SERV NEVADA,HYDROL RES FACIL,MERCURY,NV 89023. RP ISTOK, JD (reprint author), OREGON STATE UNIV,DEPT CIVIL ENGN,CORVALLIS,OR 97331, USA. NR 27 TC 12 Z9 12 U1 1 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1994 VL 32 IS 5 BP 751 EP 760 DI 10.1111/j.1745-6584.1994.tb00916.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA PE981 UT WOS:A1994PE98100007 ER PT J AU FOLGER, PF NYBERG, P WANTY, RB POETER, E AF FOLGER, PF NYBERG, P WANTY, RB POETER, E TI RELATIONSHIPS BETWEEN RN-222 DISSOLVED IN-GROUND WATER-SUPPLIES AND INDOOR RN-222 CONCENTRATIONS IN SOME COLORADO FRONT RANGE HOUSES SO HEALTH PHYSICS LA English DT Article DE RN-222; GROUND WATER; SOIL; DETECTOR, ALPHA-TRACK AB Indoor Rn-222 concentrations were measured in 37 houses with alpha track detectors placed in water-use rooms near water sources (bathrooms, laundry rooms, and kitchens) and in non-water-use living rooms, dining rooms, and bedrooms away from water sources. Results show that relative contributions of Rn-222 to indoor air from water use are insignificant when soil-gas concentrations are high but become increasingly important as the ratio of Rn-222-in-water:Rn-222-in-soil gas increases. High roil-gps Rn-222 concentrations may mask Rn contributions from water even when waterborne Rn-222 concentrations are as high as 750 kBq m(-3). Ground water in Precambrian Pikes Peak granite averages 340 kBq m(-3 222) Rn, vs. 170 kBq m(-3) in Precambrian migmatite, but average Rn-222 concentrations in soil gas are also lower in migmatite. Because the ratio of Rn-222-in-water:Rn-222-in-soil gas may be consistently higher for houses in migmatite than in Pikes Peak granite, indoor air in houses built on migmatite may have a greater relative contribution from water use even though average Rn-222 concentrations in the water are lower. Continuous monitoring of Rn-222 concentrations in air on 15-min intervals also indicates that additions to indoor concentrations from water use are significant and measurable only when soil-gas concentrations are low and concentrations in water are high. When soil-gas concentrations were mitigated to less than 150 Bq m(-3) in one house, water contributes 20-40% of the annual indoor Rn-222 concentration in the laundry room (Rn-222 concentration in water of 670 kBq m(-3)). Conversely, when the mitigation system is inactive, diurnal fluctuations and other variations in the soil-gas Rn-222 contribution swamp the variability due to water use in the house. Measurable variations in indoor concentrations from water use were not detected in one house despite a low soil-gas contribution of approximately 150 Bq m(-3) because waterborne Rn-222 concentrations also are low (80 kBq m(-3)). This result suggests that Rn-222 concentrations in water near the recommended EPA limit in drinking water of 11 kBq m(-3) may not contribute measurable amounts of Rn-222 to indoor air in most houses. C1 COLORADO SCH MINES, DEPT GEOL & GEOL ENGN, GOLDEN, CO 80401 USA. US EPA, DENVER, CO 80202 USA. RP FOLGER, PF (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 916, DENVER, CO 80225 USA. NR 9 TC 14 Z9 15 U1 0 U2 0 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 SEP PY 1994 VL 67 IS 3 BP 245 EP 253 DI 10.1097/00004032-199409000-00004 PG 9 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 PC297 UT WOS:A1994PC29700004 PM 8056590 ER PT J AU OBRIEN, AK ESHLEMAN, KN POLLARD, JS AF OBRIEN, AK ESHLEMAN, KN POLLARD, JS TI INTERACTIONS BETWEEN GROUNDWATER AND SURFACE-WATER IN A VIRGINIA COASTAL-PLAIN WATERSHED .2. ACID-BASE CHEMISTRY SO HYDROLOGICAL PROCESSES LA English DT Article DE ACID-BASE CHEMISTRY; SULFATE DEPOSITION; ACIDIFICATION; VIRGINIA COASTAL PLAIN AB An intensive study was conducted on the biogeochemical processes controlling the acid-base chemistry of Reedy Creek, a wetland-influenced coastal plain stream located near Ashland, Virginia. In the context of the hydrological processes determined by Eshleman et al., the present research sought to: (1) identify the sources and sinks of anthropogenic and organic acidity within the watershed, (2) determine the seasonal and spatial variability in the stream base flow chemistry, (3) determine the episodic variability in stream stormflow chemistry and (4) quantify a watershed sulphate budget for the 1990 water year. Sulphate is the primary acidic anion in groundwater and surface water at the Reedy Creek watershed. Dissolved organic carbon (DOC) and anion deficit data suggest that organic acids are less important than sulphate in contributing acidity to the stream. In groundwater sampled from wells installed along two transects perpendicular to the stream, sulphate concentrations were higher and alkalinity lower in the groundwater in the hillslope than in the stream. Sulphate concentrations and alkalinity observed in groundwater in the wetland were usually between those of the hillslope and stream. These data suggest that the wetland is a sink for sulphate and acidity; sulphate reduction may be an important mechanism for generating alkalinity in the wetland. The DOC concentrations were higher in the stream and wetland groundwater than in hillslope groundwater. No consistent spatial patterns in sulphate concentrations were observed in surface water chemistry under base flow conditions. Anion deficit, DOC and the sum of base cation concentrations were usually higher at upstream sites than downstream sites. At all sites, sulphate concentrations were higher and alkalinity lower in winter and spring than during summer and autumn. Calculated anion deficits were lower in winter and spring than during summer and autumn, reflecting an increase in the contribution of organic acidity during the growing season. Seasonality was not observed in DOC concentrations. Stream discharge was found to be positively correlated with base flow sulphate concentrations and inversely correlated with alkalinity. A sulphate mass balance indicated that approximately 30% of the estimated 24.9 kg SO42-/ha yr wet atmospheric input was exported from the watershed as sulphate in stream runoff in the water year 1990. RP OBRIEN, AK (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MS-432,RESTON,VA 22092, USA. RI Eshleman, Keith/J-6531-2015 NR 0 TC 7 Z9 7 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD SEP-OCT PY 1994 VL 8 IS 5 BP 411 EP 427 PG 17 WC Water Resources SC Water Resources GA PK054 UT WOS:A1994PK05400002 ER PT J AU DECOLA, L AF DECOLA, L TI SIMULATING AND MAPPING SPATIAL COMPLEXITY USING MULTISCALE TECHNIQUES SO INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SYSTEMS LA English DT Article ID FRACTAL ANALYSIS; UNITED-STATES AB A central problem in spatial analysis is the mapping of data for complex spatial fields using relatively simple data structures, such as those of a conventional GIS. This complexity can be measured using such indices as multi-scale variance, which reflects spatial autocorrelation, and multi-fractal dimension, which characterizes the values of fields. These indices are computed for three spatial processes: Gaussian noise, a simple mathematical function, and data for a random walk. Fractal analysis is then used to produce a vegetation map of the central region of California based on a satellite image. This analysis suggests that real world data lie on a continuum between the simple and the random, and that a major GIS challenge is the scientific representation and understanding of rapidly changing multi-scale fields. RP DECOLA, L (reprint author), US GEOL SURVEY,NATL CTR 521,RESTON,VA 22092, USA. NR 32 TC 10 Z9 10 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0269-3798 J9 INT J GEOGR INF SYST JI Int. J. Geogr. Inf. Syst. PD SEP-OCT PY 1994 VL 8 IS 5 BP 411 EP 427 DI 10.1080/02693799408902011 PG 17 WC Geography; Information Science & Library Science SC Geography; Information Science & Library Science GA PD651 UT WOS:A1994PD65100001 ER PT J AU STEWART, JB KUSTAS, WP HUMES, KS NICHOLS, WD MORAN, MS DEBRUIN, HAR AF STEWART, JB KUSTAS, WP HUMES, KS NICHOLS, WD MORAN, MS DEBRUIN, HAR TI SENSIBLE HEAT-FLUX RADIOMETRIC SURFACE-TEMPERATURE RELATIONSHIP FOR 8 SEMIARID AREAS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID ENERGY BALANCE; WATER; EVAPOTRANSPIRATION; SYSTEM AB Measurements of sensible heat flux, radiometric surface temperature, air temperature, and wind speed made at eight semiarid rangeland sites were used to investigate the sensible heat flux-aerodynamic resistance relationship. The individual sites covered a wide range of vegetation (0.1-4 m tall) and cover (3%-95% bare soil) conditions. Mean values of kB-1, a quantity related to the resistance of heat versus momentum transfer at the surface, for the individual sites varied between 3.5 and 12.5. A preliminary test of the utility of an excess resistance based on the mean value of kB-1 showed that the difference between the mean estimated and measured sensible heat fluxes varied +/- 60 W m-2 for the eight semiarid sites. For the eight sites the values of kB-1 were plotted against the roughness Reynolds number. The plot showed considerable scatter with values ranging between and beyond the theoretical curves for bluff rough and permeable rough surfaces. C1 AGR UNIV WAGENINGEN,6700 HB WAGENINGEN,NETHERLANDS. USDA ARS,US WATER CONSERVAT LAB,PHOENIX,AZ 85040. USDA ARS,BELTSVILLE AGR RES CTR,HYDROL LAB,BELTSVILLE,MD 20705. USGS,DIV WATER RESOURCES,CARSON CITY,NV. RP STEWART, JB (reprint author), INST HYDROL,MACLEAN BLDG,CROWNMARSH GIFFORD,WALLINGFORD OX10 8BB,OXON,ENGLAND. NR 39 TC 141 Z9 154 U1 0 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 1994 VL 33 IS 9 BP 1110 EP 1117 DI 10.1175/1520-0450(1994)033<1110:SHFRST>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PD382 UT WOS:A1994PD38200007 ER PT J AU SHANLEY, JB AF SHANLEY, JB TI EFFECTS OF ION-EXCHANGE ON STREAM SOLUTE FLUXES IN A BASIN RECEIVING HIGHWAY DEICING SALTS SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID METAL MOBILITY; MASS-BALANCE; SEA SALTS; ACIDIFICATION; PRECIPITATION; WATER; SOIL AB At Fever Brook, a 1260-ha forested basin in central Massachusetts, highway deicing salt application increased the solute flux in streamflow by 120% above background flux (equivalent basis) during a 2-yr period. Attempts to isolate the nonsalt component of stream solute fluxes have commonly subtracted salt contributions based on the net Cl flux (Cl output in streamflow minus Cl input in precipitation). In these studies, any net Na flux in excess of the amount needed to balance the net Cl flux has been attributed to weathering. At Fever Brook, however, the net output of Na was less than the net output of Cl, suggesting a loss of Na within the basin. The Na sink was inferred to be cation exchange of Na for Ca and Mg in the soil. A method was developed to quantify the exchange based on a Na budget, which included an independent estimate of the Na flux from weathering. The amount of exchange was apportioned to Ca and Mg based on their relative concentrations in the stream. The background fluxes of Ca and Mg (i.e., those that would occur in the absence of deicing salts) were calculated by subtracting the amounts from ion exchange plus the much smaller direct contributions in deicing salts from the observed fluxes. Ion exchange and direct salt contributions increased the net output fluxes of Ca and Mg, each by 44% above background. In basins that receive deicing salts, failure to account for cation exchange thus may result in an underestimate of the flux of Na from weathering and overestimates of the fluxes of Ca and Mg from weathering. RP SHANLEY, JB (reprint author), US GEOL SURVEY,POB 628,MONTPELIER,VT 05601, USA. NR 43 TC 36 Z9 37 U1 0 U2 12 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 1994 VL 23 IS 5 BP 977 EP 986 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA PG295 UT WOS:A1994PG29500018 ER PT J AU BLOHM, RJ MACKENZIE, KA AF BLOHM, RJ MACKENZIE, KA TI ADDITIONAL EVIDENCE OF MIGRATIONAL HOMING BY A PAIR OF MALLARDS SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article AB Numerous citations exist in the literature documenting homing tendencies of female ducks. There are noticeably fewer references for homing males, however, and accounts of returning pairs are scarce. The return of a pair of Mallards (Anas platyrhychos) to a wetland complex in Alberta, Canada, in two successive years is documented. A number of plausible hypotheses to explain this infrequent but interesting observation are discussed. RP BLOHM, RJ (reprint author), US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,WASHINGTON,DC 20240, USA. NR 17 TC 3 Z9 3 U1 0 U2 0 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 1994 VL 65 IS 4 BP 476 EP 478 PG 3 WC Ornithology SC Zoology GA PZ914 UT WOS:A1994PZ91400009 ER PT J AU LANCTOT, RB AF LANCTOT, RB TI BLOOD-SAMPLING IN JUVENILE BUFF-BREASTED SANDPIPERS - MOVEMENT, MASS CHANGE AND SURVIVAL SO JOURNAL OF FIELD ORNITHOLOGY LA English DT Article ID BIRDS; POPULATION; PLOVERS AB The effect of blood sampling on juvenile Buff-breasted Sandpipers (Tryngites subruficollis) was evaluated by comparing movements, mass, and survival of 10 broods (37 chicks) that were bled and eight broods (31 chicks) that were not bled. Blood was sampled from the jugular vein of chicks when they weighed 9.1 +/- 0.9 g ((x) over bar +/- SD) on or within 1 d of hatch. Chicks showed few short-term negative effects from blood sampling. individual chicks suffered little physical injury, and five of eight chicks where injury occurred (i.e., hematomas formed) survived to fledging. Further-more, bled broods gained mass at a comparable rate during the first 5 d post-hatch, and were resighted at similar frequencies as broods that were not bled. Bled broods moved slightly longer distances than control broods 1 d after hatch, however. This increased activity may have been stress-induced, but was only temporary; bled and control broods made similar long-term movements, and the probability of resighting was similar at fledging. with the proper precautions, it appears that Buff-breasted Sandpiper young can be safely sampled for blood at an early age without causing undue harm. C1 US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,NATL BIOL SURVEY,ANCHORAGE,AK 99503. RP LANCTOT, RB (reprint author), CARLETON UNIV,DEPT BIOL,1125 COLONEL BY DR,OTTAWA,ON K1S 5B6,CANADA. NR 26 TC 17 Z9 17 U1 0 U2 0 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 1994 VL 65 IS 4 BP 534 EP 542 PG 9 WC Ornithology SC Zoology GA PZ914 UT WOS:A1994PZ91400019 ER PT J AU ALMENDINGER, JE AF ALMENDINGER, JE TI THE TRAVEL-TIME ELLIPSE - AN APPROXIMATE ZONE OF TRANSPORT SO JOURNAL OF HYDROLOGY LA English DT Article AB A zone of transport for a well is defined as the area in the horizontal plane bounded by a contour of equal ground-water travel time to the well. For short distances and ground-water travel times near a well, the potentiometric surface may be simulated analytically as that for a fully penetrating well in a uniform flow field. The zone of transport for this configuration is nearly elliptical. A simple method is derived to calculate a travel-time ellipse that approximates the zone of transport for a well in a uniform flow field. The travel-time ellipse was nearly congruent with the exact solution for the theoretical zone of transport for ground-water travel times of at least 10 years and for aquifer property values appropriate for southeastern Minnesota. For distances and travel times approaching infinity, however, the ellipse becomes slightly wider at its midpoint and narrower near its upgradient boundary than the theoretical zone of transport. The travel-time ellipse also may be used to simulate the plume area surrounding an injection well. However, the travel-time ellipse is an approximation that does not account for the effect of dispersion in enlarging the true area of an injection plume or zone of transport; hence, caution is advised in the use and interpretation of this simple construction. RP ALMENDINGER, JE (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,2280 WOODALE DR,MOUNDS VIEW,MN 55112, USA. NR 13 TC 3 Z9 3 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 SEP PY 1994 VL 161 IS 1-4 BP 365 EP 373 DI 10.1016/0022-1694(94)90135-X PG 9 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PG570 UT WOS:A1994PG57000018 ER PT J AU HOLTZ, TR AF HOLTZ, TR TI THE PHYLOGENETIC POSITION OF THE TYRANNOSAURIDAE - IMPLICATIONS FOR THEROPOD SYSTEMATICS SO JOURNAL OF PALEONTOLOGY LA English DT Review ID STENONYCHOSAURUS-INEQUALIS SAURISCHIA; EARLY EVOLUTION; DINOSAURS; ORIGIN; SKELETON; BIRDS; ARCHAEOPTERYX; AUBLYSODON AB Tyrannosaurids are a well-supported clade of very large predatory dinosaurs of Late Cretaceous Asiamerica. Traditional dinosaurian systematics place these animals within the infraorder Carnosauria with the other large theropods (allosaurids, megalosaurids). A new cladistic analysis indicates that the tyrannosaurs were in fact derived members of the Coelurosauria, a group of otherwise small theropods. Despite certain gross cranial similarities with the large predators of the Jurassic and Early Cretaceous, the Late Cretaceous tyrannosaurids are shown to be the sister group to ornithomimids and troodontids, which share a derived condition of the metatarsus. This clade is found to be nested within Maniraptora, which is a more inclusive taxon than previously recognized- The atrophied carpal structure found in tyrannosaurids and ornithomimids is derived from a maniraptoran condition with a large semilunate carpal, rather than from the plesiomorphic theropod morphology. The taxa ''Carnosauria'' and ''Deinonychosauria'' (Dromaeosauridae plus Troodontidae) are shown to be polyphyletic, and the Late Jurassic African form Elaphrosaurus is found to be the sister taxon to Abelisauridae rather than a primitive ornithomimosaur. Purported allosaurid-tyrannosaurid synapomorphies are seen to be largely size-related, present in the larger members of both clades, but absent in smaller members of the Tyrannosauridae. The remaining giant tetanurine theropods (Megalosaurus and Torvosaurus) were found to be progressively distant outgroups to an allosaurid-coelurosaur clade. The inclusion of the Tyrannosauridae within Maniraptora suggests a major adaptive radiation of coelurosaurs within Cretaceous Asiamerica comparable to contemporaneous radiations in various herbivorous dinosaurian clades. RP HOLTZ, TR (reprint author), US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,MS 970 NATL CTR,RESTON,VA 22092, USA. NR 157 TC 180 Z9 188 U1 0 U2 18 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD SEP PY 1994 VL 68 IS 5 BP 1100 EP 1117 PG 18 WC Paleontology SC Paleontology GA PJ918 UT WOS:A1994PJ91800014 ER PT J AU CLOERN, JE COLE, BE HAGER, SW AF CLOERN, JE COLE, BE HAGER, SW TI NOTES ON A MESODINIUM-RUBRUM RED TIDE IN SAN-FRANCISCO BAY (CALIFORNIA, USA) SO JOURNAL OF PLANKTON RESEARCH LA English DT Note ID PHOTOTROPHIC CILIATE; ESTUARY; DYNAMICS AB Discrete red patches of water were observed in South San Francisco Bay (USA) on 30 April 1993, and examination of live samples showed that this red tide was caused by surface accumulations of the pigmented ciliate Mesodinium rubrum. Vertical profiles showed strong salinity and temperature stratification in the upper 5 m, peak chlorophyll fluorescence in the upper meter, and differences in the small-scale density structure and fluorescence distribution among red patches. Events preceding this Mesodinium red tide included: (i) heavy precipitation and run-off, allowing for strong salinity stratification; (ii) a spring diatom bloom where the chlorophyll a concentration reached 50 mg m(-3); (ii) depletions of dissolved inorganic N and Si in the photic zone; and (iv) several days of rapid warming and stabilization of the upper surface layer. These conditions may be general prerequisites for M rubrum blooms in temperate estuaries. C1 US GEOL SURVEY,MENLO PK,CA 94025. RI Cloern, James/C-1499-2011; OI Cloern, James/0000-0002-5880-6862 NR 13 TC 17 Z9 18 U1 0 U2 2 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD SEP PY 1994 VL 16 IS 9 BP 1269 EP 1276 DI 10.1093/plankt/16.9.1269 PG 8 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PH485 UT WOS:A1994PH48500010 ER PT J AU SABO, BA LAYBOURNE, RC AF SABO, BA LAYBOURNE, RC TI PREPARATION OF AVIAN MATERIAL RECOVERED FROM PELLETS AND AS PREY REMAINS SO JOURNAL OF RAPTOR RESEARCH LA English DT Note DE FOOD HABITS TECHNIQUE; PREPARATION FOR FEATHER IDENTIFICATION; PREY ANALYSIS C1 SMITHSONIAN INST,DIV BIRDS,WASHINGTON,DC 20560. RP SABO, BA (reprint author), US FISH & WILDLIFE SERV,NATL FISH & WILDLIFE FORENS LAB,1490 E MAIN ST,ASHLAND,OR 97520, USA. NR 8 TC 15 Z9 15 U1 0 U2 3 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 1994 VL 28 IS 3 BP 192 EP 193 PG 2 WC Ornithology SC Zoology GA PL683 UT WOS:A1994PL68300012 ER PT J AU KNITTLE, CE PAVELKA, MA AF KNITTLE, CE PAVELKA, MA TI HOOK AND LOOP TABS FOR ATTACHING A DHO-GAZA SO JOURNAL OF RAPTOR RESEARCH LA English DT Letter C1 US FISH & WILDLIFE SERV,CARLSBAD,CA 92008. RP KNITTLE, CE (reprint author), USDA,DENVER WILDLIFE RES CTR,BLDG 16,FED CTR,DENVER,CO 80225, USA. NR 7 TC 0 Z9 0 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 1994 VL 28 IS 3 BP 197 EP 198 PG 2 WC Ornithology SC Zoology GA PL683 UT WOS:A1994PL68300014 ER PT J AU DEIN, FJ WILSON, A FISCHER, D LANGENBERG, P AF DEIN, FJ WILSON, A FISCHER, D LANGENBERG, P TI AVIAN LEUKOCYTE COUNTING USING THE HEMOCYTOMETER SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Note DE BIRDS; HEMOCYTOMETER COUNTING; BLOOD CELLS; LEUKOCYTES; COUNTING METHODS AB Automated methods for counting leucocytes in avian blood are not available because of the presence of nucleated erythrocytes and thrombocytes. Therefore, total white blood cell counts are performed by hand using a hemocytometer. The Natt and Herrick and the Unopette methods are the most common stain and diluent preparations for this procedure. Replicate hemocytometer counts using these two methods were performed on blood from four birds of different species. Cells present in each square of the hemocytometer were counted. Counting cells in the corner, side, or center hemocytometer squares produced statistically equivalent results; counting four squares per chamber provided a result similar to that obtained by counting nine squares; and the Unopette method was more precise for hemocytometer counting than was the Natt and Herrick method. The Unopette method is easier to learn and perform but is an indirect process, utilizing the differential count from a stained smear. The Natt and Herrick method is a direct total count, but cell identification is more difficult. C1 SMITHSONIAN INST,NATL ZOOL PK,WASHINGTON,DC 20008. UNIV MARYLAND,DEPT EPIDEMIOL & PREVENT MED,BALTIMORE,MD 21201. RP DEIN, FJ (reprint author), US FISH & WILDLIFE SERV,NATL WILDLIFE HLTH RES CTR,6006 SHROEDER RD,MADISON,WI 53711, USA. NR 28 TC 31 Z9 31 U1 2 U2 10 PU AMER ASSOC Z00 VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD SEP PY 1994 VL 25 IS 3 BP 432 EP 437 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA PF358 UT WOS:A1994PF35800011 ER PT J AU FRANSON, JC GALBREATH, EJ WIEMEYER, SN ABELL, JM AF FRANSON, JC GALBREATH, EJ WIEMEYER, SN ABELL, JM TI ERYSIPELOTHRIX-RHUSIOPATHIAE INFECTION IN A CAPTIVE BALD EAGLE (HALIAEETUS-LEUCOCEPHALUS) SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Note DE BALD EAGLE; HALIAEETUS-LEUCOCEPHALUS; ERYSIPELOTHRIX-RHUSIOPATHIAE; SEPTICEMIA AB An adult bald eagle (Haliaeetus leucocephalus) kept in captivity for nearly 7 yr at the Patuxent Wildlife Research Center, Laurel, Maryland, died suddenly with gross and microscopic lesions characteristic of septicemia. Erysipelothrix rhusiopathiae was isolated from the liver. Fish comprised part of the bird's diet and may have been the source of the organism. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. UNIV WISCONSIN,DEPT PATHOBIOL SCI,MADISON,WI 53706. MARYLAND DEPT AGR,COLLEGE PK,MD 20704. NR 13 TC 2 Z9 2 U1 1 U2 2 PU AMER ASSOC Z00 VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD SEP PY 1994 VL 25 IS 3 BP 446 EP 448 PG 3 WC Veterinary Sciences SC Veterinary Sciences GA PF358 UT WOS:A1994PF35800013 ER PT J AU MCCONNAUGHEY, TA LABAUGH, JW ROSENBERRY, DO STRIEGL, RG REDDY, MM SCHUSTER, PF CARTER, V AF MCCONNAUGHEY, TA LABAUGH, JW ROSENBERRY, DO STRIEGL, RG REDDY, MM SCHUSTER, PF CARTER, V TI CARBON BUDGET FOR A GROUNDWATER-FED LAKE - CALCIFICATION SUPPORTS SUMMER PHOTOSYNTHESIS SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID O-18 ISOTOPIC DISEQUILIBRIUM; BICARBONATE ASSIMILATION; BIOLOGICAL CARBONATES; INORGANIC CARBON; WILLIAMS-LAKE; MASS BALANCE; CO2; EVAPORATION; MINNESOTA; EXCHANGE AB A chemical budget analysis for Williams Lake, Minnesota, tracks the seasonal progression of carbon inputs and outputs. CO2 exchanges with the atmosphere reverse seasonally, with uptake by the lake in summer preceded and followed by larger losses to the atmosphere. Calcium bicarbonate-rich groundwaters seep steadily into the lake, augmented by remobilization of lacustrine marls. Most of the carbon used in summer photosynthesis nevertheless derives from depletion of lake carbon stores, facilitated significantly by plant calcification. Calcification in summer reduces alkalinity and calcium inventories by 15 and 25%, respectively, while generating equal molar quantities of CO2. Marl precipitates mainly on submersed macrophytes, several of which calcify in 1:1 ratio to photosynthesis when incubated in Ca-supplemented lake water. Despite calcite supersaturation within the epilimnion, there is little authigenic calcification. C1 US GEOL SURVEY,BOULDER,CO 80303. US GEOL SURVEY,RESTON,VA 22092. RP MCCONNAUGHEY, TA (reprint author), US GEOL SURVEY,BOX 25046,MS 413,DENVER,CO 80225, USA. RI Rosenberry, Donald/C-2241-2013; OI Rosenberry, Donald/0000-0003-0681-5641 NR 30 TC 62 Z9 67 U1 0 U2 12 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 SEP PY 1994 VL 39 IS 6 BP 1319 EP 1332 PG 14 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA PP788 UT WOS:A1994PP78800007 ER PT J AU CHEZAR, H HAGEY, WH AF CHEZAR, H HAGEY, WH TI MICROPROCESSOR-CONTROLLED REAL-TIME IMAGING-SYSTEM SO SEA TECHNOLOGY LA English DT Article C1 PISCES DESIGN,SAN DIEGO,CA. RP CHEZAR, H (reprint author), US GEOL SURVEY,PACIFIC MARINE GEOL BRANCH,MENLO PK,CA 94025, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 1994 VL 35 IS 9 BP 61 EP 64 PG 4 WC Engineering, Ocean SC Engineering GA PH632 UT WOS:A1994PH63200012 ER PT J AU KEENLYNE, KD HENRY, CJ TEWS, A CLANCEY, P AF KEENLYNE, KD HENRY, CJ TEWS, A CLANCEY, P TI MORPHOMETRIC COMPARISONS OF UPPER MISSOURI RIVER STURGEONS SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article AB Morphometric comparisons were made among three isolated populations of pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus from the upper Missouri River. Six measurements were made on 89 pallid and 204 shovelnose sturgeons. Means of several morphometric characteristics were statistically different between populations of both species. Pallid sturgeon means showed proportional trends relative to location on the river. Toward the head-waters, relative head and interrostral lengths were progressively shorter and outer barbel length relatively longer. The only trend observed for the shovelnose sturgeon was that relative head length became longer upriver. This was the opposite of the trend observed for the pallid sturgeon. Morphometric ratios commonly used to differentiate the two species were useful measures for live fish from isolated populations of Missouri River sturgeon but not for the overall sturgeon population. The exclusivity of morphometric ratios currently used to distinguish between the two species did not hold for our larger fish and large sample size. A cumulative morphometric characteristic index is described to aid managers in comparing individual fish within a composite sturgeon population, and the finding of three possible hybrids is discussed. C1 MONTANA DEPT FISH WILDLIFE & PK,FT BENTON,MT 59442. MONTANA DEPT FISH WILDLIFE & PK,ENNIS,MT 59729. RP KEENLYNE, KD (reprint author), US FISH & WILDLIFE SERV,420 S GARFIELD AVE,SUITE 400,PIERRE,SD 57501, USA. NR 13 TC 24 Z9 25 U1 0 U2 4 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 SEP PY 1994 VL 123 IS 5 BP 779 EP 785 DI 10.1577/1548-8659(1994)123<0779:MCOUMR>2.3.CO;2 PG 7 WC Fisheries SC Fisheries GA PH637 UT WOS:A1994PH63700008 ER PT J AU GOFF, BF BENT, GC HART, GE AF GOFF, BF BENT, GC HART, GE TI INFLUENCE OF RAINFALL INTENSITY ON THE INTERRILL ERODIBILITY OF 2 RANGELAND SOILS SO TRANSACTIONS OF THE ASAE LA English DT Article DE EROSION; SOIL CONSERVATION; SEDIMENTATION; RAIN SIMULATOR; HYDROLOGIC MODELING ID EROSION MODEL; PREDICTION AB Rangelands are subject to wide variations in rainfall intensity, and rainfall intensify is an important parameter in erosion models. This study measured interrill erosion rates for two rangeland soils for different rainfall intensities using a laboratory rainfall simulator. Both the general power equation E = aI(b), and its constant exponent form E = cI(2) (where E is interrill erosion rate, I is rainfall intensity, a and b are fitted parameters, and c is an interrill erodibility coefficient), adequately modeled interrill erosion response (r(2) > 0.93 and r(2) > 0.83 for the two models, respectively). These results indicate that the constant exponent model can be applied to rangeland soils. Interrill erodibility coefficients, c, for natural rainfall conditions were estimated to be 6.5 x 10(5) kg s m(-4) for the sandy loam soil and 8.8 x 10(4) kg s m(-4) for the clay loam soil. These values were one to two orders of magnitude lower than those reported for agricultural soils, but were within the range for rangeland soils. C1 UTAH STATE UNIV,WATERSHED SCI UNIT,LOGAN,UT. RP GOFF, BF (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MARLBOROUGH,MA, USA. NR 19 TC 2 Z9 2 U1 0 U2 1 PU AMER SOC AGR ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 SN 0001-2351 J9 T ASAE JI Trans. ASAE PD SEP-OCT PY 1994 VL 37 IS 5 BP 1445 EP 1448 PG 4 WC Agricultural Engineering SC Agriculture GA PX698 UT WOS:A1994PX69800008 ER PT J AU HEJZLAR, J SZPAKOWSKA, B WERSHAW, RL AF HEJZLAR, J SZPAKOWSKA, B WERSHAW, RL TI COMPARISON OF HUMIC SUBSTANCES ISOLATED FROM PEATBOG WATER BY SORPTION ON DEAE-CELLULOSE AND AMBERLITE XAD-2 SO WATER RESEARCH LA English DT Article DE AQUATIC HUMIC SUBSTANCES; PEATBOG WATER; AMBERLITE XAD-2; DIETHYLAMINOETHYL CELLULOSE; C-13-NMR SPECTROSCOPY; ULTRAVIOLET-VISIBLE SPECTROSCOPY; INFRARED SPECTROSCOPY; SEPHADEX GEL CHROMATOGRAPHY; NEUTRAL SUGARS; AMINO SUGARS; AMINO ACIDS ID FUNCTIONAL-GROUPS; ACID; CHROMATOGRAPHY AB Aquatic humic substances (AHS) were isolated from peatbog water by adsorption (1) on diethylaminoethyl cellulose (DEAE-C) and (2) on Amberlite XAD-2 (XAD) to compare yields of the methods and the composition of the isolated AHS. To provide a detailed comparison, the isolates were fractionated using size-exclusion and hydrophobic-interaction chromatography on Sephadex G-50. The fractions were characterized by ultraviolet-visible, infrared and C-13-nuclear magnetic spectroscopies and analyzed for elemental, functional-group, carbohydrate and amino acid compositions. More AHS adsorbed onto DEAE-C than onto XAD-2 (94 and 74%, respectively). However, only 76% of the AHS adsorbed onto DEAE-C was recovered using 0.1 M NaOH, whereas 98% of the AHS adsorbed onto XAD was released by consecutive elution with 1 M NH4OH (91%) and methanol (7%). Four main fractions of different composition were obtained from each of the alkali-desorbed AHS samples by Sephadex-gel chromatography. General agreement was found in relative amounts, spectroscopic characteristics and composition of corresponding fractions of both isolates except nitrogen content, which was significantly higher in AHS isolated with XAD, apparently due to the reaction of AHS with NH4OH used for the desorption from the resin. C1 POLISH ACAD SCI,DEPT AGROBIOL & FORESTRY,PL-60809 POZNAN,POLAND. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP HEJZLAR, J (reprint author), ACAD SCI CZECH REPUBL,INST HYDROBIOL,NA SADKACH 7,CR-37005 CESKE BUDEJOVICE,CZECH REPUBLIC. RI Hejzlar, Josef/F-8526-2014 NR 32 TC 15 Z9 17 U1 0 U2 6 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 SEP PY 1994 VL 28 IS 9 BP 1961 EP 1970 DI 10.1016/0043-1354(94)90171-6 PG 10 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA NW950 UT WOS:A1994NW95000012 ER PT J AU HELGESEN, JO ZELT, RB STAMER, JK AF HELGESEN, JO ZELT, RB STAMER, JK TI NITROGEN AND PHOSPHORUS IN WATER AS RELATED TO ENVIRONMENTAL SETTING IN NEBRASKA SO WATER RESOURCES BULLETIN LA English DT Article DE WATER QUALITY; STATISTICAL ANALYSIS; NONPOINT SOURCE POLLUTION; LAND USE; NITROGEN; PHOSPHORUS AB Spatial distributions of nitrogen and phosphorus in water were related to environmental setting as part of a regional water-quality assessment of the Central Nebraska Basins. The environmental settings (Sandhills, Loess Hills, Glaciated Area, and Platte Valley) were characterized by different concentrations of nitrogen and phosphorus in ground water and stream water. Statistically significant differences in nitrate concentrations in both ground-water and stream-water samples were related to regional distributions of cropland and rangeland. Nitrate concentrations were larger, especially in shallow ground water, in environmental settings dominated by cropland and associated fertilizer use than in settings dominated by rangeland. Similarly, total-nitrogen and nitrate concentrations were relatively large in selected streams draining primarily cropland. Comparative concentrations of phosphorus in stream water on the basis of environmental setting were similar to those of nitrogen, although the largest phosphorus concentrations probably relate to wastewater discharge into small streams. Nitrogen and phosphorus concentrations in much of the Platte River apparently reflected the quality of water entering the study unit from upstream and limited base-flow contributions from within the Platte Valley itself. RP HELGESEN, JO (reprint author), US GEOL SURVEY,WRD,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. OI Zelt, Ronald/0000-0001-9024-855X NR 16 TC 5 Z9 5 U1 1 U2 4 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD SEP-OCT PY 1994 VL 30 IS 5 BP 809 EP 822 PG 14 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PP609 UT WOS:A1994PP60900005 ER PT J AU STAMER, JK SWANSON, RB JORDAN, PR AF STAMER, JK SWANSON, RB JORDAN, PR TI ATRAZINE IN SPRING RUNOFF AS RELATED TO ENVIRONMENTAL SETTING IN NEBRASKA, 1992 SO WATER RESOURCES BULLETIN LA English DT Article DE ATRAZINE; NONPOINT SOURCE POLLUTION; SURFACE WATER HYDROLOGY; WATER QUALITY ID MIDWESTERN UNITED-STATES; SURFACE WATERS; HERBICIDES AB A synoptic sampling of five surface-water sites in central Nebraska was conducted by the U.S. Geological Survey as part of its National Water-Quality Assessment Program during storm runoff in May 1992 to relate transport, yields, and concentrations of atrazine to environmental setting. Atrazine was the most extensively applied pesticide in the study unit. Atrazine transport was related to the size of contributing drainage area, quantity of atrazine applied, amount of precipitation, and volume of streamflow. Estimated yields and mean concentrations of atrazine were related to the percentage of cropland in a drainage area. The largest estimated yields and mean concentrations of atrazine in surface water were associated from drainage areas with the highest percentage of cropland, and the smallest was associated with the smallest amount of cropland. Atrazine concentrations increased as streamflows, increased but decreased at or near the time of peak streamflows, perhaps due to dilution. Atrazine concentrations then increased and remained elevated far into the stream recession. Atrazine is a regulated contaminant in finished public-water supplies. Large concentrations of atrazine could affect the management of public-water supplies because atrazine remains in solution in contrast to many other pesticides that are more easily removed. C1 US GEOL SURVEY,N PLATTE,NE 69103. RP STAMER, JK (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. NR 25 TC 14 Z9 14 U1 0 U2 2 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD SEP-OCT PY 1994 VL 30 IS 5 BP 823 EP 831 PG 9 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PP609 UT WOS:A1994PP60900006 ER PT J AU DUELL, LFW AF DUELL, LFW TI THE SENSITIVITY OF NORTHERN SIERRA-NEVADA STREAMFLOW TO CLIMATE-CHANGE SO WATER RESOURCES BULLETIN LA English DT Article DE SURFACE WATER HYDROLOGY; REGRESSION ANALYSIS; STATISTICAL MODELS; CLIMATE CHANGE; SIERRA-NEVADA; TEMPERATURE; PRECIPITATION ID WATER-RESOURCES; RIVER BASIN; CALIFORNIA AB The sensitivity of streamflow to climate change was investigated in the American, Carson, and Truckee River Basins, California and Nevada. Nine gaging stations were used to represent streamflow in the basins. Annual models were developed by regressing 1961-1991 streamflow data on temperature and precipitation. Climate-change scenarios were used as inputs to the models to determine streamflow sensitivities. Climate-change scenarios were generated from historical time series by modifying mean temperatures by a range of +4-degrees-C to -4-degrees-C and total precipitation by a range of +25 percent to -25 percent. Results show that streamflow on the warmer, lower west side of the Sierra Nevada generally is more sensitive to temperature and precipitation changes than is streamflow on the colder, higher east side. A 2-degrees-C rise in temperature and a 25-percent decrease in precipitation results in streamflow decreases of 56 percent on the American River and 25 percent on the Carson River. A 2-degrees-C decline in temperature and a 25-percent increase in precipitation results in streamflow increases of 102 percent on the American River and 22 percent on the Carson River. RP DUELL, LFW (reprint author), US GEOL SURVEY,5735 KEARNY VILLA RD,SUITE O,SAN DIEGO,CA 92123, USA. NR 17 TC 15 Z9 15 U1 4 U2 14 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD SEP-OCT PY 1994 VL 30 IS 5 BP 841 EP 859 PG 19 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PP609 UT WOS:A1994PP60900008 ER PT J AU LOPEZ, NC AF LOPEZ, NC TI BEYOND BUZZ WORDS SO WATER RESOURCES BULLETIN LA English DT Editorial Material RP LOPEZ, NC (reprint author), US GEOL SURVEY,417 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD SEP-OCT PY 1994 VL 30 IS 5 BP R3 EP R3 PG 1 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PP609 UT WOS:A1994PP60900001 ER PT J AU ROSS, DS BARTLETT, RJ MAGDOFF, FR WALSH, GJ AF ROSS, DS BARTLETT, RJ MAGDOFF, FR WALSH, GJ TI FLOW PATH STUDIES IN FORESTED WATERSHEDS OF HEADWATER TRIBUTARIES OF BRUSH BROOK, VERMONT SO WATER RESOURCES RESEARCH LA English DT Article ID MODELING STREAMWATER CHEMISTRY; SOILWATER END-MEMBERS; SOIL SOLUTIONS; CATCHMENT; ACIDIFICATION; ALUMINUM; MIXTURE; CATIONS; LAKE; USA AB An investigation was undertaken into how headwater tributaries of Brush Brook, Vermont, could have average pH differences of almost two units (4.75 and 6.7). Sampling along four tributaries revealed that mast of one tributary, below an area of seeps, had consistently higher pH, Ca2+, Mg2+, and K+, and lower Al than other sites. Bedrock mapping showed numerous fractures in vicinity of the seeps. A portion of this tributary's watershed and a portion of an acid tributary's watershed were intensively mapped for soil depth. Sampling showed the widespread existence of dense basal till in the watershed of the; acid tributary but none in:that of the near-neutral stream. Lateral flow, found above the dense till, was chemically similar to that of the acid tributary and to solutions sampled from soil B horizons. There were no differences in the average pH of nonseep soils sampled from either watershed. Flow paths are hypothesized to be through the B horizons in the acid tributaries and from below the soil profile in the near-neutral tributary. The acid catchment should be more sensitive to environmental change. C1 US GEOL SURVEY, NATL CTR, RESTON, VA 22092 USA. RP ROSS, DS (reprint author), UNIV VERMONT, DEPT PLANT & SOIL SCI, BURLINGTON, VT 05401 USA. RI Ross, Donald/A-4477-2008 OI Ross, Donald/0000-0002-5390-6602 NR 28 TC 25 Z9 26 U1 0 U2 2 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 SEP PY 1994 VL 30 IS 9 BP 2611 EP 2618 DI 10.1029/94WR01490 PG 8 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA PE742 UT WOS:A1994PE74200011 ER PT J AU MELVIN, SM HECHT, A GRIFFIN, CR AF MELVIN, SM HECHT, A GRIFFIN, CR TI PIPING PLOVER MORTALITIES CAUSED BY OFF-ROAD VEHICLES ON ATLANTIC COAST BEACHES SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE ATLANTIC COAST; CHARADRIUS-MELODUS; ENDANGERED SPECIES; MASSACHUSETTS; MORTALITY; NEW-YORK; OFF-ROAD VEHICLE; PIPING PLOVER ID PREDATOR EXCLOSURES; NESTS C1 US FISH & WILDLIFE SERV,SUDBURY,MA 01776. UNIV MASSACHUSETTS,HOLDSWORTH NAT RESOURCES CTR,DEPT FORESTRY & WILDLIFE MANAGEMENT,AMHERST,MA 01003. RP MELVIN, SM (reprint author), MASSACHUSETTS DIV FISHERIES & WILDLIFE,ROUTE 135,WESTBOROUGH,MA 01581, USA. NR 14 TC 21 Z9 22 U1 0 U2 8 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 1994 VL 22 IS 3 BP 409 EP 414 PG 6 WC Biodiversity Conservation SC Biodiversity & Conservation GA PH858 UT WOS:A1994PH85800006 ER PT J AU KREMENTZ, DG SEGINAK, JT PENDLETON, GW AF KREMENTZ, DG SEGINAK, JT PENDLETON, GW TI WINTER MOVEMENTS AND SPRING MIGRATION OF AMERICAN WOODCOCK ALONG THE ATLANTIC COAST SO WILSON BULLETIN LA English DT Article AB Radio transmitters were attached to American Woodcock (Scolopax minor) at three Atlantic coastal sites to monitor winter movements and spring departure dates from Georgia (1982-1984, 1989-1991), South Carolina (1988-1989), and Virginia (1991-1992). There was no evidence of temperature, sex, or age-dependent migration dates. Migration was coincident with the full moon in February and the passage of weather fronts close to this time. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. RP KREMENTZ, DG (reprint author), UNIV GEORGIA,WARNELL SCH FOREST RESOURCES,SE RES GRP,PATUXENT WILDLIFE RES CTR,ATHENS,GA 30602, USA. NR 33 TC 10 Z9 10 U1 1 U2 10 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 SEP PY 1994 VL 106 IS 3 BP 482 EP 493 PG 12 WC Ornithology SC Zoology GA PK023 UT WOS:A1994PK02300007 ER PT J AU MARKS, DK NASLUND, NL AF MARKS, DK NASLUND, NL TI SHARP-SHINNED HAWK PREYS ON A MARBLED MURRELET NESTING IN OLD-GROWTH FOREST SO WILSON BULLETIN LA English DT Note ID DISCOVERY RP MARKS, DK (reprint author), US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT,1011 E TUDOR RD,ANCHORAGE,AK 99503, USA. NR 17 TC 2 Z9 3 U1 0 U2 1 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 SEP PY 1994 VL 106 IS 3 BP 565 EP 567 PG 3 WC Ornithology SC Zoology GA PK023 UT WOS:A1994PK02300020 ER PT J AU HOLZER, TL AF HOLZER, TL TI PREDICTING EARTHQUAKE EFFECTS - LEARNING FROM NORTHRIDGE AND LOMA-PRIETA SO SCIENCE LA English DT Editorial Material RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MAIL STOP 977, MENLO PK, CA 94025 USA. NR 8 TC 3 Z9 4 U1 0 U2 1 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 AUG 26 PY 1994 VL 265 IS 5176 BP 1182 EP 1183 DI 10.1126/science.265.5176.1182 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PD422 UT WOS:A1994PD42200021 PM 17787579 ER PT J AU REASENBERG, PA JONES, LM AF REASENBERG, PA JONES, LM TI EARTHQUAKE AFTERSHOCKS - UPDATE SO SCIENCE LA English DT Article C1 US GEOL SURVEY,PASADENA,CA 91106. RP REASENBERG, PA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 1 TC 98 Z9 98 U1 0 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 26 PY 1994 VL 265 IS 5176 BP 1251 EP 1252 DI 10.1126/science.265.5176.1251 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PD422 UT WOS:A1994PD42200045 PM 17787593 ER PT J AU OREM, WH LYONS, PC LERCH, HE AF OREM, WH LYONS, PC LERCH, HE TI ORGANIC GEOCHEMISTRY OF MODERN AND FOSSIL RESINS OF VARYING DIAGENETIC STATE AND RANK SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,NATL CTR 956,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 5 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101950 ER PT J AU MARKS, C BREEN, JJ PALMER, C PRICE, E ANDERSON, D AF MARKS, C BREEN, JJ PALMER, C PRICE, E ANDERSON, D TI CHEMICAL SOCIETY OF WASHINGTON KIDS AND CHEMISTRY PROGRAM - CHEMISTS AND THEIR LOCAL SECTION IN-SERVICE TO THE COMMUNITY THROUGH CHEMICAL EDUCATION SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 SAIC INC,TYSONS CORNER,VA. US GEOL SURVEY,RESTON,VA 22092. US EPA,WASHINGTON,DC 20460. NIH,BETHESDA,MD 20892. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 10 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101517 ER PT J AU REDDY, MM AF REDDY, MM TI CALCIUM-CARBONATE FORMATION IN PYRAMID LAKE, NEVADA SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,BOULDER,CO 80303. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 11 EP COLL PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101071 ER PT J AU BARBASH, JE AF BARBASH, JE TI PROBLEMS ASSOCIATED WITH THE USE OF SOLUTE-TRANSPORT MODELS AND VULNERABILITY ASSESSMENTS FOR PREDICTING THE BEHAVIOR OF PESTICIDES IN THE SUBSURFACE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 32 EP AGRO PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26100200 ER PT J AU BATES, AL SPIKER, EC AF BATES, AL SPIKER, EC TI SPECIATION AND ISOTOPIC COMPOSITION OF SULFUR IN THE FLORIDA EVERGLADES SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 50 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101995 ER PT J AU MEYER, MT THURMAN, EM AF MEYER, MT THURMAN, EM TI THE TRANSPORT OF CYANAZINE AND ATRAZINE METABOLITES IN THE UNSATURATED ZONE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,LAWRENCE,KS 66049. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 61 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101568 ER PT J AU KOOPMANS, MP LEWAN, MD DAMSTE, JSS DELEEUW, JW AF KOOPMANS, MP LEWAN, MD DAMSTE, JSS DELEEUW, JW TI THERMALLY-INDUCED TRANSFORMATIONS OF ORGANIC SULFUR-COMPOUNDS AND SULFUR-RICH GEOMACROMOLECULES AS REVEALED BY HYDROUS PYROLYSIS SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NETHERLANDS INST SEA RES,1790 AB DEN BURG,NETHERLANDS. US GEOL SURVEY,DENVER,CO 80225. RI de Leeuw, Jan/F-6471-2011 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 63 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26102008 ER PT J AU COZZARELLI, IM BAEDECKER, MJ FISCHER, JM PHINNEY, CS AF COZZARELLI, IM BAEDECKER, MJ FISCHER, JM PHINNEY, CS TI GROUNDWATER CONTAMINATION BY PETROLEUM-HYDROCARBONS - NATURAL BIODEGRADATION IN A DYNAMIC HYDROLOGIC AND GEOCHEMICAL SYSTEM SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,W TRENTON,NJ 08628. US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 80 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101587 ER PT J AU KOOPMANS, MP DAMSTE, JSS LEWAN, MD DELEEUW, JW AF KOOPMANS, MP DAMSTE, JSS LEWAN, MD DELEEUW, JW TI DISTINCT PRECURSORS FOR PRISTANE AND PHYTANE IN THE MARINE-ENVIRONMENT IMPACT ON THE RATIONALE AND USE OF THE PR/PH RATIO SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NETHERLANDS INST SEA RES,1790 AB DEN BURG,NETHERLANDS. US GEOL SURVEY,DENVER,CO 80225. RI de Leeuw, Jan/F-6471-2011 NR 0 TC 0 Z9 0 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 97 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26102042 ER PT J AU SEEWALD, JS SEYFRIED, WE SHANKS, WC AF SEEWALD, JS SEYFRIED, WE SHANKS, WC TI REDUCTION OF SULFUR SPECIES DURING HYDROTHERMAL SEDIMENT ALTERATION - AN EXPERIMENTAL-STUDY SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 104 EP GEOC PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26102049 ER PT J AU YU, K CHANNEL, S TILLITT, D BURTON, A MCCAFFERTY, J HANCOCK, B SCHMIDT, B FISHER, J AF YU, K CHANNEL, S TILLITT, D BURTON, A MCCAFFERTY, J HANCOCK, B SCHMIDT, B FISHER, J TI COMPARISON OF IN-VITRO AND IN-VIVO DOSE-RESPONSE STUDY OF A SOIL CONTAMINANT, PCB=77 SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US FISH & WILDLIFE SERV,NATL FISHERIES CONTAMINANT RES CTR,COLUMBIA,MO 65201. WRIGHT STATE UNIV,DEPT BIOL SCI,DAYTON,OH 45435. ARMSTRONG LAB,DIV TOXICOL,AL OETA,WRIGHT PATTERSON AFB,OH 45433. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 104 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101611 ER PT J AU ALLEY, WM AF ALLEY, WM TI REFLECTIONS ON NETWORK DESIGN FOR REGIONAL GROUNDWATER QUALITY TREND ANALYSIS 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 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 121 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101628 ER PT J AU MORGANWALP, DW AF MORGANWALP, DW TI MODELING GROUNDWATER CONTAMINATION FROM INJECTION WELL FAILURES 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 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 144 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101651 ER PT J AU LEBO, JA GALE, RW PETTY, JD TILLITT, DE HUCKINS, JN MEADOWS, JC ECHOLS, KR INMON, L AF LEBO, JA GALE, RW PETTY, JD TILLITT, DE HUCKINS, JN MEADOWS, JC ECHOLS, KR INMON, L TI ANALYSES OF PCDD PCDF RESIDUES SEQUESTERED FROM ENVIRONMENTAL WATERS BY THE SEMIPERMEABLE-MEMBRANE DEVICE SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL BIOL SURVEY,NATL FISHERIES CONTAMINANT RES CTR,COLUMBIA,MO 65201. US FISH & WILDLIFE SERV,VICKSBURG FIELD OFF,VICKSBURG,MS 39180. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 21 PY 1994 VL 208 BP 226 EP ENVR PN 1 PG 0 WC Chemistry, Multidisciplinary SC Chemistry GA PA261 UT WOS:A1994PA26101733 ER PT J AU HEDENQUIST, JW LOWENSTERN, JB AF HEDENQUIST, JW LOWENSTERN, JB TI THE ROLE OF MAGMAS IN THE FORMATION OF HYDROTHERMAL ORE-DEPOSITS SO NATURE LA English DT Review ID PORPHYRY COPPER-DEPOSITS; CONVERGENT PLATE BOUNDARIES; NEW-ZEALAND; GEOTHERMAL SYSTEMS; AUGUSTINE VOLCANO; FLUID INCLUSION; ISOTOPE RATIOS; WHITE-ISLAND; ACID-SULFATE; GOLD DEPOSIT AB Magmatic fluids, both vapour and hypersaline liquid, are a primary source of many components in hydrothermal ore deposits formed in volcanic arcs. These components, including metals and their ligands, become concentrated in magmas in various ways from various sources, including subducted oceanic crust. Leaching of rocks also contributes components to the hydrothermal fluid-a process enhanced where acid magmatic vapours are absorbed by deeply circulating meteoric waters. Advances in understanding the hydrothermal systems that formed these ore deposits have come from the study of their active equivalents, represented at the surface by hot springs and volcanic fumaroles. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP HEDENQUIST, JW (reprint author), GEOL SURVEY JAPAN,DEPT MINERAL RESOURCES,TSUKUBA,IBARAKI 305,JAPAN. OI Lowenstern, Jacob/0000-0003-0464-7779 NR 88 TC 764 Z9 912 U1 18 U2 176 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 18 PY 1994 VL 370 IS 6490 BP 519 EP 527 DI 10.1038/370519a0 PG 9 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PC537 UT WOS:A1994PC53700045 ER PT J AU MOUM, T JOHANSEN, S ERIKSTAD, KE PIATT, JF AF MOUM, T JOHANSEN, S ERIKSTAD, KE PIATT, JF TI PHYLOGENY AND EVOLUTION OF THE AUKS (SUBFAMILY ALCINAE) BASED ON MITOCHONDRIAL-DNA SEQUENCES SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BIRDS; GENE AB The genetic divergence and phylogeny of the auks was assessed by mitochondrial DNA sequence comparisons in a study using 19 of the 22 auk species and two outgroup representatives. We compared more than 500 nucleotides from each of two mitochondrial genes encoding 12S rRNA and the NADH dehydrogenase subunit 6. Divergence times were estimated from transversional substitutions. The dovekie (Alle alle) is related to the razorbill (Alca torda) and the murres (Uria spp). Furthermore, the Xantus's murrelet (Synthliboramphus hypoleucus) and the ancient (Synthliboramphus antiquus) and Japanese murrelets (Synthliboramphus wumizusume) are genetically distinct members of the same main lineage, whereas brachyramphine and synthliboramphine murrelets are not closely related. An early adaptive radiation of six main species groups of auks seems to trace back to Middle Miocene. Later speciation probably involved ecological differentiations and geographical isolations. C1 UNIV TROMSO,INST MED BIOL,DEPT BIOCHEM,N-9037 TROMSO,NORWAY. UNIV TROMSO,INST MED BIOL,DEPT CELL BIOL,N-9037 TROMSO,NORWAY. NORWEGIAN INST NAT RES,DEPT TROMSO,N-9001 TROMSO,NORWAY. US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. NR 26 TC 40 Z9 41 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 16 PY 1994 VL 91 IS 17 BP 7912 EP 7916 DI 10.1073/pnas.91.17.7912 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PC242 UT WOS:A1994PC24200018 PM 8058734 ER PT J AU GADDIS, LR AF GADDIS, LR TI EVALUATION OF AN EMPIRICAL RADAR BACKSCATTER MODEL FOR PREDICTING BACKSCATTER CHARACTERISTICS OF GEOLOGIC UNITS AT PISGAH VOLCANIC FIELD, CALIFORNIA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IMAGING RADAR; SCATTERING; INVERSION; SURFACES AB Comparison of radar backscatter coefficients (sigma-degrees, in dB), calculated by using the empirical model of Oh et al, [1992], to sigma-degrees extracted from AIRSAR data of four geologic units at Pisgah shows that the model predicts measured sigma-degrees(vv) and sigma-degrees(hv) to within +/- 3 dB. The model predicts higher sigma-degrees(hh) than those observed. For smooth surfaces (rms height = s, s < 8 cm), model results depend strongly on the accuracy of the surface measurements (s and dielectric constant, epsilon(r)). For rougher surfaces, the model is less dependent on the accuracy of surface characterizations. The model may be inverted to estimate s from measured sigma-degrees for surfaces with ks < 3 (k = wavenumber, or 2pi/lambda, where lambda = radar wavelength). Model inversion for a pahoehoe unit at 30-degrees to 50-degrees incidence angles (theta) resulted in an estimate of s to within < 1 cm of the measured 3 cm. The inability of the model to estimate accurately sigma-degrees(hh) and the anomalously high nadir Fresnel reflection coefficients (GAMMA(o)) and epsilon(r) required in the model inversion may both be due to approximately equal co-polarized ratios (sigma-degrees(hh)/sigma-degrees(vv) = P approximately 1) of the soils used to derive the model. For effective application to many geologic surfaces, for which p < 1 is often observed at theta > 30-degrees, the model will require modification to include surfaces with non-unity sigma-degrees(hh)/sigma-degrees(vv). RP GADDIS, LR (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 14 TC 1 Z9 1 U1 0 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 1994 VL 21 IS 17 BP 1803 EP 1806 DI 10.1029/94GL01253 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PC817 UT WOS:A1994PC81700015 ER PT J AU HAGSTRUM, JT LIPMAN, PW SAWYER, DA AF HAGSTRUM, JT LIPMAN, PW SAWYER, DA TI PALEOMAGNETISM, STRATIGRAPHY, AND PETROLOGY OF THE UPPER CRETACEOUS ROSKRUGE VOLCANICS AT BELL MOUNTAIN, SOUTHEAST ARIZONA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MONTANA AB Reconnaissance geologic mapping and petrologic study of the Upper Cretaceous Roskruge Volcanics at Bell Mountain in the Roskruge Mountains, southeastern Arizona, have identified five compositionally distinct ash flow tuffs, including the basal red Viopuli Tuff, which comprise six or seven separate cooling units. Previous paleomagnetic investigators inferred eleven cooling units at Bell Mountain, but insufficient information was given to determine which tuffs had been sampled. This study was undertaken therefore to establish characteristic remanence directions for each tuff sheet. The available paleomagnetic data corroborate the identification of five map units in the Bell Mountain area, but the number of independent observations is too few for the calculation of a reliable paleopole; paleosecular variation of the geomagnetic field would probably not be averaged out. No correlatable tuffs are present at Bell Mountain, so relative vertical axis rotations cannot be determined, although they are probably not large. The absence of regionally correlatable tuffs suggests the presence of additional, potentially mineralized, volcanic centers perhaps farther north in the Roskruge Mountains or buried nearby beneath Cenozoic basin fill. C1 US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RP HAGSTRUM, JT (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 23 TC 3 Z9 3 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 1994 VL 99 IS B8 BP 15097 EP 15102 DI 10.1029/94JB00802 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000001 ER PT J AU HAGSTRUM, JT AF HAGSTRUM, JT TI REMAGNETIZATION OF JURASSIC VOLCANIC-ROCKS IN THE SANTA-RITA AND PATAGONIA MOUNTAINS, ARIZONA - IMPLICATIONS FOR NORTH-AMERICAN APPARENT POLAR WANDER SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LATE CRETACEOUS PALEOMAGNETISM; SOUTH CENTRAL ARIZONA; SOUTHEASTERN ARIZONA; NEWARK BASIN; IGNEOUS ROCKS; NEW-MEXICO; POLES; SUMMERVILLE; CONTROVERSY AB Paleomagnetic poles for the Jurassic Corral Canyon sequence and Glance Conglomerate in southern Arizona have been used to construct apparent polar wander (APW) paths for the North American plate, but they are controversial and conflict with higher-latitude poles from New England. Lower Jurassic dacites and ash flow tuffs of the Mount Wrightson Formation in the Santa Rita Mountains were initially sampled to provide an additional paleopole for southern Arizona. These rocks, however, have a predominantly reversed-polarity characteristic magnetization (in situ, I = -47-degrees, D = 154-degrees, alpha95 = 9-degrees) which is statistically indistinguishable from that for the nearby latest Cretaceous Elephant Head pluton (I = -48-degrees, D = 165-degrees, alpha95 = 8-degrees). Although magnetizations of both polarities are observed in the ash flow tuffs, they are mostly carried by hematite, and dual polarity components are observed within some specimens. Moreover, widespread mineralization and a K-Ar age of approximately 67 Ma for altered rocks of the Mount Wrightson Formation imply that these rocks were subjected to a prolonged episode (greater than one polarity interval) of low-temperature alteration and remagnetization. Middle Jurassic ash flow tuffs of the Corral Canyon sequence in the Patagonia Mountains to the south have a similar geologic setting: They are exposed along strike amid mineralized rocks on the eastern flank of a mountain range cored by Paleocene intrusions. Hematite is also the dominant remanence carrier in most of the Corral Canyon sequence, and its predominantly normal-polarity direction (in situ, I 51-degrees, D = 326-degrees, alpha95 = 9-degrees) is indistinguishable from that for the nearby Patagonia Granodiorite (I = 49-degrees, D = 342-degrees, alpha95 = 8-degrees). Rocks of the Corral Canyon sequence therefore are likely remagnetized as well. Problems also exist with the Glance Conglomerate pole. These rocks are situated within a caldera structure and have been potassium metasomatized. This potassic alteration could have occurred shortly after emplacement or at a later time, postdeformation. The low-latitude Jurassic APW path for North America and J-2 cusp therefore are not well supported and may need revision. RP HAGSTRUM, JT (reprint author), US GEOL SURVEY, BRANCH ISOTOPE GEOL, MS 937, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 47 TC 2 Z9 2 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 1994 VL 99 IS B8 BP 15103 EP 15113 DI 10.1029/94JB01056 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000002 ER PT J AU JOLLY, AD PAGE, RA POWER, JA AF JOLLY, AD PAGE, RA POWER, JA TI SEISMICITY AND STRESS IN THE VICINITY OF MOUNT-SPURR VOLCANO, SOUTH CENTRAL ALASKA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EARTHQUAKE; PLATE AB Focal mechanism solutions and hypocenters for earthquakes near Mount Spurr volcano in south central Alaska reveal spatial perturbations in the regional stress field and in the maximum depth of seismicity. At the volcano, practically all the shocks during the dormant decade 1981-1991 have depths shallower than 5 km and are characterized by nearly pure normal slip. In contrast, earthquakes located outboard of the volcano mostly concentrate in the depth range 3-18 km and exhibit predominantly strike slip, oblique reverse slip, or reverse slip. The regional stress field is characterized by subhorizontal maximum principal stress directed N30-degrees-W, concordant with the direction of convergence between the North American and Pacific plates, whereas the maximum principal stress is probably more nearly vertical beneath the volcano. We suggest that the shoaling of seismicity beneath the volcano reflects localized elevation of the depth to the midcrustal transition from brittle failure to plastic flow. We attribute this localized elevation to relict magmatic heat associated with past volcanic eruptions. The available data are not sufficient to determine the cause of the suggested rotation of the maximum principal stress axis beneath the volcano; possible mechanisms include an increase in the vertical stress from the weight of the Mount Spurr massif and a decrease in the maximum horizontal stress associated with doming of the shallow crust from magmatic processes. C1 US GEOL SURVEY, ALASKA VOLCANO OBSERV, MENLO PK, CA 94025 USA. RP JOLLY, AD (reprint author), UNIV ALASKA, INST GEOPHYS, US GEOL SURVEY, ALASKA VOLCANO OBSERV, FAIRBANKS, AK 99775 USA. NR 21 TC 26 Z9 26 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 1994 VL 99 IS B8 BP 15305 EP 15318 DI 10.1029/94JB00136 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000014 ER PT J AU DURRHEIM, RJ MOONEY, WD AF DURRHEIM, RJ MOONEY, WD TI EVOLUTION OF THE PRECAMBRIAN LITHOSPHERE - SEISMOLOGICAL AND GEOCHEMICAL CONSTRAINTS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID UPPER-MANTLE STRUCTURE; PROTEROZOIC CRUSTAL EVOLUTION; SOUTH-AFRICA; SEISMIC REFRACTION; HEAT-FLOW; VELOCITY STRUCTURE; CONTINENTAL-CRUST; CANADIAN SHIELD; SUBCONTINENTAL MANTLE; CRATONIC LITHOSPHERE AB Several recent models of crustal evolution are based on the belief that the thickness of the continental crust is proportional to its age, with ancient crust being the thickest. A worldwide review of seismic structure contradicts this belief and falsifies these models, at least for the Archean. Proterozoic crust has a thickness of 40-55 km and a substantial high-velocity (>7 km/s) layer at its base, while Archean crust is only 2740 km thick (except at the site of younger rifts and collisional boundaries) and lacks the basal high-velocity layer. Seismology also provides evidence that the lithosphere is thickest beneath Archean cratons, while diamond ages show that this lithospheric keel must have already existed in the Archean. Geochemical data also indicate significant differences between Archean and Proterozoic lithosphere. Major and trace element studies of sediments show a change in upper crustal composition between the Archean and Proterozoic. Archean rocks are depleted in Si and K and enriched in Na, Ca, and Mg. There is also a marked change in the Eu/Eu* ratio. Mantle xenoliths and continental flood basalts show that the mantle lithosphere beneath Archean crust is ultradepleted in FeO compared to that beneath post-Archean crust. The secular change in the crust-forming process is attributed to a decline in mantle temperature, leading to a change in the composition of the lithospheric mantle. The higher temperature of the Archean mantle led to the eruption of komatiitic lavas, producing a refractory lithospheric mantle which is ultradepleted in FeO and volatiles. The resultant lithospheric keel is intrinsically less dense than the surrounding mantle and thus not susceptible to delamination. It was sufficiently thick and cool for diamonds to form during the Archean. In contrast, Proterozoic crust developed above fertile mantle. The eruption of continental flood basalts and underplating of basaltic sills is attributed to subsequent heating and partial melting of the lithospheric mantle. Consequently, Proterozoic crust is thickened and has a high-velocity basal layer. C1 UNIV WITWATERSRAND, DEPT GEOPHYS, JOHANNESBURG 2001, SOUTH AFRICA. US GEOL SURVEY, MENLO PK, CA 94025 USA. NR 122 TC 170 Z9 175 U1 0 U2 17 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 1994 VL 99 IS B8 BP 15359 EP 15374 DI 10.1029/94JB00138 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000017 ER PT J AU GOT, JL FRECHET, J KLEIN, FW AF GOT, JL FRECHET, J KLEIN, FW TI DEEP FAULT PLANE GEOMETRY INFERRED FROM MULTIPLET RELATIVE RELOCATION BENEATH THE SOUTH FLANK OF KILAUEA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CROSS-SPECTRAL-ANALYSIS; SEISMIC REFRACTION; CRUSTAL STRUCTURE; 1975 KALAPANA; HAWAII; EARTHQUAKE; LOCATIONS; VOLCANO; MODEL; MECHANISM AB Dense microearthquake swarms occur in the upper south flank of Kilauea, providing multiplets composed of hundreds of events. The similarity of their waveforms and the quality of the data have been sufficient to provide accurate relative relocations of their hypocenters. A simple and efficient method has been developed which allowed the relative relocation of more than 250 events with an average precision of about 50 m horizontally and 75 m vertically. Relocation of these events greatly improves the definition of the seismic image of the fault that generates them. Indeed, relative relocations define a plane dipping about 6-degrees northward, although corresponding absolute locations are widely dispersed in the swarm. A composite focal mechanism, built from events providing a correct spatial sampling of the multiplet, also gives a well-constrained northward dip of about 5-degrees to the near-horizontal plane. This technique thus collapses the clouds of hypocenters of single-event locations to a plane coinciding with the slip plane revealed by previous focal mechanism studies. We cannot conclude that all south flank earthquakes collapse to a single plane. There may locally be several planes, perhaps with different dips and depths throughout the south flank volume. The 6-degrees northward-dipping plane we found is too steep to represent the overall flexure of the oceanic crust under the load of the island of Hawaii. This plane is probably an important feature that characterizes the basal slip layer below the upper south flank of Kilauea volcano. Differences in seismicity rate and surface deformations between the upper and lower south flank could be related to the geometry of this deep fault plane. The present work illustrates how high precision relative relocations of similar events in dense swarms, combined with the analysis of geodetic measurements, can help to describe deep fault plane geometry. Systematic selection and extensive relative relocation of similar earthquakes could be attempted in other well-instrumented, highly seismic areas to provide reliable basic information, especially useful for understanding of earthquake generation processes. C1 OBSERV GRENOBLE, GEOPHYS INTERNE & TECTONOPHYS LAB, F-38041 GRENOBLE, FRANCE. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP GOT, JL (reprint author), UNIV SAVOIE, F-73376 LE BOURGET DU LAC, FRANCE. NR 29 TC 245 Z9 254 U1 1 U2 18 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 1994 VL 99 IS B8 BP 15375 EP 15386 DI 10.1029/94JB00577 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000018 ER PT J AU YANG, HJ FREY, FA GARCIA, MO CLAGUE, DA AF YANG, HJ FREY, FA GARCIA, MO CLAGUE, DA TI SUBMARINE LAVAS FROM MAUNA-KEA VOLCANO, HAWAII - IMPLICATIONS FOR HAWAIIAN SHIELD STAGE PROCESSES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ISOTOPIC CONSTRAINTS; HALEAKALA VOLCANO; GEOCHEMICAL EVOLUTION; KILAUEA VOLCANO; LOIHI SEAMOUNT; MAJOR-ELEMENT; TRACE-ELEMENT; EAST MAUI; BASALTS; ORIGIN AB The island of Hawaii is composed of five voluminous shields but only the youngest, active and well-exposed shields of Mauna Loa and Kilauea have been studied in detail. The shield lavas forming Kohala, Hualalai and Mauna Kea are largely covered by postshield lavas with geochemical characteristics that differ from the shield lavas. In order to determine the geochemical characteristics of the Mauna Kea shield which is adjacent to the Kilauea and Mauna Loa shields, 12 Mauna Kea shield basalts dredged from the submarine east rift were analyzed for major and trace element contents and isotopic (Sr, Nd, and Pb) ratios. The lavas are MgO-rich (11 to 20%), submarine erupted, tholeiitic basalts, but they are not representative of crystallized MgO-rich melts. Their whole rock and mineral compositions are consistent with mixing of an evolved magma, <7% MgO, with a magma containing abundant olivine xenocrysts, probably disaggregated from a dunitic cumulate. At a given MgO content, some of the Mauna Kea whole rocks have lower abundances of CaO and higher abundances of incompatible elements. The evolved melt component in these lavas reflects significant fractionation of plagioclase and clinopyroxene and in some cases even the late crystallizing phases orthopyroxene and Fe-Ti oxide. Although these Mauna Kea lavas are not isotopically homogeneous, in general their Sr, Nd and Pb isotopic ratios overlap with the fields for lavas from Loihi and Kilauea volcanoes. Lavas from these three shields define the low Sr-87/Sr-86, high Pb-206/Pb-204, and low Zr/Nb ranges for Hawaiian shield lavas, and they may contain a larger proportion of a component with high U-238/Pb-204. Most of these Mauna Kea shield lavas, however, are distinguished from Kilauea and Loihi tholeiitic basalts by having lower La/Ce and La/Yb. These data provide additional evidence that each Hawaiian shield has distinctive geochemical characteristics. C1 US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HAWAII NATL PK, HI 96716 USA. UNIV HAWAII, DEPT GEOL & GEOPHYS, HONOLULU, HI 96822 USA. RP YANG, HJ (reprint author), MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, ROOM 541220, CAMBRIDGE, MA 02139 USA. NR 54 TC 44 Z9 44 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 AUG 10 PY 1994 VL 99 IS B8 BP 15577 EP 15594 DI 10.1029/94JB00895 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000034 ER PT J AU CHAMPION, DE DONNELLYNOLAN, JM AF CHAMPION, DE DONNELLYNOLAN, JM TI DURATION OF ERUPTION AT THE GIANT CRATER LAVA-FIELD, MEDICINE LAKE VOLCANO, CALIFORNIA, BASED ON PALEOMAGNETIC SECULAR VARIATION SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID NORTHERN CALIFORNIA; IDAHO AB Nearly 500 cores were collected from the postglacial Giant Crater lava field on the south flank of Medicine Lake volcano. The basaltic lavas form a continuous set of lava flows which display strong chemical zonation from initially erupted calc-alkaline basaltic andesite to final primitive basalt of tholeiitic affinity. Six chemical-stratigraphic groups have been recognized and mapped. The eruptive sequence was sampled at numerous sites both to determine the characteristic paleomagnetic direction of each chemical group and to estimate the duration of the eruption inferred from secular variation of the geomagnetic field. Well-grouped mean directions of magnetization were obtained for 41 sites in the Giant Crater lava field. Mean directions of magnetization determined for the lava field are nearly identical. The likelihood of any extended time interval for the eruption of the different lava types is extremely small, and the data suggest an eruptive event of less than 30 years duration, analogous to historic Hawaiian eruptions. However, the average of groups 1-4, which cannot be distinguished paleomagnetically from each other, is slightly different statistically from that of the average of groups 5 and 6, which have similar directions. A time gap of 10 +/- 5 years is inferred between eruption of group 4 and 5 lavas based on analysis of the probability of the observed angular difference of 1.27-degrees +/- 0.84-degrees between their mean directions and by comparison of this angular difference to calculated field directions with similar declination and inclination determined from spherical harmonic models of the geomagnetic field for the time period 1945-1990. About 200 oriented cores were also collected from predecessor and successor basaltic lava flows on the upper flanks of the volcano. Together with remanent directions from lavas of the Snake River Plain the data define a clockwise loop of secular variation. RP US GEOL SURVEY, MS 937, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 18 TC 6 Z9 6 U1 2 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 AUG 10 PY 1994 VL 99 IS B8 BP 15595 EP 15604 DI 10.1029/94JB00900 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB520 UT WOS:A1994PB52000035 ER PT J AU HOUSTON, H VIDALE, JE AF HOUSTON, H VIDALE, JE TI TEMPORAL DISTRIBUTION OF SEISMIC RADIATION DURING DEEP EARTHQUAKE RUPTURE SO SCIENCE LA English DT Article ID FOCUS EARTHQUAKES; EARTHS MANTLE; MECHANISM; WATER AB The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period seismic radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is released toward the beginning of the rupture than near the end, whereas for deep events radiation is released symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP HOUSTON, H (reprint author), UNIV CALIF SANTA CRUZ,INST TECTON,DEPT EARTH SCI,SANTA CRUZ,CA 95064, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 21 TC 22 Z9 22 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD AUG 5 PY 1994 VL 265 IS 5173 BP 771 EP 774 DI 10.1126/science.265.5173.771 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PA372 UT WOS:A1994PA37200030 PM 17736276 ER PT J AU OREMLAND, RS BLUM, JS CULBERTSON, CW VISSCHER, PT MILLER, LG DOWDLE, P STROHMAIER, FE AF OREMLAND, RS BLUM, JS CULBERTSON, CW VISSCHER, PT MILLER, LG DOWDLE, P STROHMAIER, FE TI ISOLATION, GROWTH, AND METABOLISM OF AN OBLIGATELY ANAEROBIC, SELENATE-RESPIRING BACTERIUM, STRAIN SES-3 SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; ELEMENTAL SELENIUM; THAUERA-SELENATIS; DISSIMILATORY REDUCTION; ESTUARINE SEDIMENTS; ELECTRON-ACCEPTOR; NITRATE; OXIDATION; RESPIRATION; IRON AB A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2, with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental selenium (Se-0). Hence, SES-3 can carry out a complete reduction of selenate to Se-0. Washed cell suspensions of selenate-grown cells did not reduce nitrate, and nitrate-grown cells did not reduce selenate, indicating that these reductions are achieved by separate inducible enzyme systems. However, both nitrate-grown and selenate-grown cells have a constitutive ability to reduce selenite or nitrite. The oxidation of [C-14]lactate to (CO2)-C-14 coupled to the reduction of selenate or nitrate by cell suspensions was inhibited by CCCP (carbonyl cyanide m-chlorophenylhydrazone), cyanide, and azide. High concentrations of selenite (5 mM) were readily reduced to Se-0 by selenate-grown cells, but selenite appeared to block the synthesis of pyruvate dehydrogenase. Tracer experiments with [Se-75]selenite indicated that cell suspensions could achieve a rapid and quantitative reduction of selenite to Se-0. This reduction was totally inhibited by sulfite, partially inhibited by selenate or nitrite, but unaffected by sulfate or nitrate, Cell suspensions could reduce thiosulfate, but not sulfite, to sulfide. These results suggest that reduction of selenite to Se-0 may proceed, in part, by some of the components of a dissimilatory system for sulfur oxyanions. RP OREMLAND, RS (reprint author), US GEOL SURVEY,MS 465,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. OI Visscher, Pieter/0000-0001-6911-1532 NR 53 TC 146 Z9 150 U1 3 U2 19 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 AUG PY 1994 VL 60 IS 8 BP 3011 EP 3019 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA NZ703 UT WOS:A1994NZ70300051 PM 16349362 ER PT J AU CUSTER, TW BICKHAM, JW LYNE, TB LEWIS, T RUEDAS, LA CUSTER, CM MELANCON, MJ AF CUSTER, TW BICKHAM, JW LYNE, TB LEWIS, T RUEDAS, LA CUSTER, CM MELANCON, MJ TI FLOW-CYTOMETRY FOR MONITORING CONTAMINANT EXPOSURE IN BLACK-CROWNED NIGHT-HERONS SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DNA ANALYSIS; RESERVOIR; SCRIPTA; DAMAGE AB The flow cytometry method (FCM) was employed to determine cellular DNA content of black-crowned night-heron (Nycticorax nycticorax) embryos and 10-day-old chicks collected at sites differing in types of chemical contamination. The coefficient of variation of DNA content (CV) in blood collected from embryos suggested cytogenetic damage at a site in Louisiana known to be contaminated with petroleum. Blood CV from chicks suggested genetic damage at a site in Texas also known to be contaminated with petroleum. Spleen CVs in chicks were significantly lower than respective means from the reference site. The CVs of chick blood and liver and spleen negatively correlated, suggesting recovery of spleen and liver cells after exposure to a clastogenic compound. Thus, the lower CVs may also have been indicative of genetic damage. Based on the findings of this study, FCM is a potential indicator of certain environmental contaminants in black-crowned night-herons. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,NATL BIOL SURVEY,LAUREL,MD 20708. TEXAS A&M UNIV,DEPT WILDLIFE & FISHERIES,COLLEGE STN,TX 77843. RP CUSTER, TW (reprint author), PATUXENT WILDLIFE RES CTR,NATL BIOL SURVEY,POB 818,LA CROSSE,WI 54602, USA. RI Custer, Christine/H-4871-2014; OI Custer, Thomas/0000-0003-3170-6519 NR 25 TC 44 Z9 44 U1 0 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 AUG PY 1994 VL 27 IS 2 BP 176 EP 179 PG 4 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT637 UT WOS:A1994NT63700005 PM 8060161 ER PT J AU HOTHEM, RL WELSH, D AF HOTHEM, RL WELSH, D TI CONTAMINANTS IN EGGS OF AQUATIC BIRDS FROM THE GRASSLANDS OF CENTRAL CALIFORNIA SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID SELENIUM; MALLARDS; REPRODUCTION; BORON AB Eggs were collected from the Grasslands of western Merced County, California, during 1986 and 1987, and at the Mendota Wildlife Area in Fresno County in 1987, as part of a reproductive study of nesting ducks and shorebirds. The eggs were analyzed to evaluate the effects of contaminants in agricultural drainwater on avian reproduction. Agricultural drainwater was the major source of water for irrigation and fall flooding in the Grasslands until the fall of 1985 when drainwater was mostly replaced by uncontaminated water. Drainwater had not been used at Mendota. Concentrations of arsenic and boron in eggs from all sites were lower than those known to harm avian reproduction. However, mean concentrations of selenium, a trace element known to impair avian reproduction at high dietary levels, were higher in eggs from the Grasslands than in eggs from the uncontaminated site. Although some selenium concentrations were as high as those found to have caused death or deformities at other sites, reproductive impairment was not observed in any ducks or shorebirds nesting in the Grasslands in 1986 or 1987. C1 US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,NATL BIOL SURVEY,LAUREL,MD 20708. NR 26 TC 14 Z9 14 U1 0 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 AUG PY 1994 VL 27 IS 2 BP 180 EP 185 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT637 UT WOS:A1994NT63700006 PM 8060162 ER PT J AU HAMILTON, SJ WADDELL, B AF HAMILTON, SJ WADDELL, B TI SELENIUM IN EGGS AND MILT OF RAZORBACK SUCKER (XYRAUCHEN-TEXANUS) IN THE MIDDLE GREEN RIVER, UTAH SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID MINNOW PIMEPHALES-PROMELAS; LEPOMIS-MACROCHIRUS; FATHEAD MINNOWS; REPRODUCTION; ACCUMULATION; BLUEGILLS; COLORADO; TISSUE; FISH AB Eggs from three female and milt from five male endangered razorback suckers (Xyrauchen texanus) were collected from the Razorback Bar (about 20 km upstream of Ashley Creek) in the Green River of northeastern Utah. Eggs, but not milt, had concentrations of selenium that were above the range of selenium concentrations in control fish from laboratory studies or reference fish from field studies. The concentrations, however, were below those reported in selenium-exposed fish that had reproductive problems in laboratory studies or field investigations. Tests with three streamside spawned pairs of razorback suckers, which were sampled for eggs and milt in this study, resulted in no hatching of fertilized eggs. Concentrations of selenium in eggs and milt were significantly correlated with selenium concentrations in muscle plugs taken from the same fish, but egg and milt concentrations were not significantly different from muscle plugs. Selenium concentrations in eggs of razorback suckers in the Green River may be sufficiently elevated to cause reproductive problems that are contributing to the decline of this species in the upper Colorado River basin. C1 US FISH & WILDLIFE SERV,ECOL SERV,SALT LAKE CITY,UT 84104. RP HAMILTON, SJ (reprint author), US FISH & WILDLIFE SERV,NATL FISHERIES CONTAMINANT RES CTR,FIELD RES STN,RR 1,BOX 295,YANKTON,SD 57078, USA. NR 24 TC 26 Z9 27 U1 0 U2 6 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 AUG PY 1994 VL 27 IS 2 BP 195 EP 201 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT637 UT WOS:A1994NT63700008 PM 8060163 ER PT J AU GIESY, JP VERBRUGGE, DA OTHOUT, RA BOWERMAN, WW MORA, MA JONES, PD NEWSTED, JL VANDERVOORT, C HEATON, SN AULERICH, RJ BURSIAN, SJ LUDWIG, JP LUDWIG, M DAWSON, GA KUBIAK, TJ BEST, DA TILLITT, DE AF GIESY, JP VERBRUGGE, DA OTHOUT, RA BOWERMAN, WW MORA, MA JONES, PD NEWSTED, JL VANDERVOORT, C HEATON, SN AULERICH, RJ BURSIAN, SJ LUDWIG, JP LUDWIG, M DAWSON, GA KUBIAK, TJ BEST, DA TILLITT, DE TI CONTAMINANTS IN FISHES FROM GREAT-LAKES-INFLUENCED SECTIONS AND ABOVE DAMS OF 3 MICHIGAN RIVERS .1. CONCENTRATIONS OF ORGANO-CHLORINE INSECTICIDES, POLYCHLORINATED-BIPHENYLS, DIOXIN EQUIVALENTS, AND MERCURY SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DOUBLE-CRESTED CORMORANTS; HEPATOMA-CELL BIOASSAY; EATING SEA BIRDS; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN EQUIVALENTS; EGGS; HYDROCARBONS; RESIDUES; PCBS; REPRODUCTION; METABOLISM AB Fishes of the Great Lakes contain hazardous chemicals such as synthetic halogenated hydrocarbons and metals. These fish can move from the lakes into the Great Lakes tributaries of Michigan. In doing so, they transport concentrations of contaminants which may represent a risk to wildlife. Concentrations of mercury (Hg), total polychlorinated biphenyls (PCBs), 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), total DDT complex, aldrin, endrin, dieldrin, heptachlor, heptachlor epoxide, lindane, hexachlorobenzene, cis-chlordane, oxychlordane, endosulfan-I, methoxychlor, trans-chlordane, and trans-nonachlor were determined in composite samples of fishes from above and below Michigan hydroelectric dams, which separate the fishes which have access to the Great Lakes from fishes that do not. Mean concentrations of total PCBs, TCDD-EQ, DDT, and most of the other pesticides were greater in composite samples of six species of fishes from below than above the dams on the Au Sable, Manistee, and Muskegon Rivers. Concentrations of mercury, were the same or greater above the dams than below. However, this difference was statistically significant only on the Au Sable. Mercury concentrations ranged from less than 0.05 mg/kg to 0.73 mg Hg/kg, ww. Total concentrations of PCBs ranged from 0.02 to 1.7 mg/kg, ww. Concentrations of 2,3,7,8-tetrachlordibenzo-p-dioxin equivalents varied among fishes and locations. The concentrations of TCDD-EQ ranged from 2.4 to 71 mug/kg, ww, with concentrations in carp being the greatest. Concentrations of TCDD-EQ were greater than the concentrations which would be expected to occur, due solely to the presence of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and technical mixtures of PCBs. C1 MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT ANIM SCI,E LANSING,MI 48824. SERE GRP LTD,VICTORIA V8P 3C8,BC,CANADA. CONSUMERS POWER CO,DEPT ENVIRONM,JACKSON,MI 49201. US FISH & WILDLIFE SERV,E LANSING FIELD OFF,E LANSING,MI 48823. NATL FISHERIES CONTAMINANT RES CTR,NATL BIOL SURVEY,COLUMBIA,MO 65201. RP GIESY, JP (reprint author), MICHIGAN STATE UNIV,PESTICIDE RES CTR,DEPT FISHERIES & WILDLIFE,E LANSING,MI 48824, USA. RI Mora, Miguel/B-1344-2009; Jones, Paul/O-2046-2015 OI Jones, Paul/0000-0002-7483-5380 FU NIEHS NIH HHS [ES-04911] NR 53 TC 44 Z9 49 U1 1 U2 9 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 AUG PY 1994 VL 27 IS 2 BP 202 EP 212 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT637 UT WOS:A1994NT63700009 PM 8060164 ER PT J AU GIESY, JP VERBRUGGE, DA OTHOUT, RA BOWERMAN, WW MORA, MA JONES, PD NEWSTED, JL VANDERVOORT, C HEATON, SN AULERICH, RJ BURSIAN, SJ LUDWIG, JP DAWSON, GA KUBIAK, TJ BEST, DA TILLITT, DE AF GIESY, JP VERBRUGGE, DA OTHOUT, RA BOWERMAN, WW MORA, MA JONES, PD NEWSTED, JL VANDERVOORT, C HEATON, SN 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 .2. IMPLICATIONS FOR HEALTH OF MINK SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID DOUBLE-CRESTED CORMORANTS; POLYCHLORINATED-BIPHENYLS AROCLOR-1016; MIXED-FUNCTION OXIDASES; VITAMIN-A LEVELS; MUSTELA-VISON; 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN EQUIVALENTS; DIETARY HEPTACHLOR; FRACTIONS THEREOF; FACTORS TEFS; PCB AB Populations of mink (Mustela vison) have declined in many areas of the world. Such declines have been linked to exposures to synthetic, halogenated hydrocarbons. In the Great Lakes region, mink are fewer in areas along the shore of the Great Lakes and their tributaries where mink have access to fish from the Great Lakes. Recently, there has been discussion of the relative merits of passage of fishes around hydroelectric dams on rivers in Michigan. A hazard assessment was conducted to determine the potential for adverse effects on mink, which could consume such fishes from above or below dams on the rivers. Concentrations of organochlorine insecticides, poly-chlorinated biphenyls (PCBs), 2,3,7,8-tetrachlordibenzo-p-dioxin equivalents (TCDD-EQ), and total mercury were measured in composite samples of fishes from above or below hydroelectric dams on the Manistee and Muskegon Rivers, which flow into Lake Michigan, and the Au Sable River, which flows into Lake Huron. Concentrations of organochlorine insecticides, PCBs, and TCDD-EQ were all greater in fishes from below the dams than those from above. Concentrations of neither organochlorine insecticides nor mercury in fishes are currently a risk to mink above or below the dams. All of the species of fishes collected from downstream of the dams contained concentrations of PCBs and TCDD-EQ, which represent a hazard to mink. The hazard index for PCBs was less than one for the average of all species from the upstream reaches of the Manistee and Au Sable Rivers, but not the Muskegon. The hazard index (concentration in fish/NOAEC) was greater than 1 for all of the species collected from below the dams, in all three rivers. The greatest hazard index was observed for carp (Cyprinus carpio) downstream on the Muskegon River. Because the concentrations of PCBs used in the hazard assessment were corrected for relative toxic potencies, the hazard ratios based on PCBs should be similar to those based on TCDD-EQ. This was found to be true. Thus, either total PCBs or TCDD-EQ could be used as the critical toxicant in the hazard assessment. However, if uncorrected concentrations of PCBs, expressed as Aroclors(R), were used in the hazard assessment, the toxicity of the weathered mixture would have been underestimated by approximately five-fold, and, in that instance, TCDD-EQ would be the critical contaminant for the hazard assessment. The average maximum allowable percentage of fish from above the dams, which would result in no observable adverse effects of TCDD-EQ, was 70%. Based on the average TCDD-EQ concentrations in the fishes, an average of 8.6% of the diet could be made up of fishes from below dams on the rivers. The most restrictive daily allowable intakes were for carp on the Muskegon and steelhead trout (Onchorhyncus mykiss) on the Manistee Rivers. Only 2.7% of the diet could be made up of these two species from below dams without exceeding the no-effect concentration. This would represent approximately 15 days of food intake. Currently, consumption of all species of fish from below the dams would pose some risk to mink. The concentrations of PCBs and TCDD-EQ in fishes from below the dams were 10-20 times more hazardous, on average, than those from above the dams. C1 MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT ANIM SCI,E LANSING,MI 48824. SERE GRP,VICTORIA V8P 3C8,BC,CANADA. CONSUMERS POWER CO,DEPT ENVIRONM,JACKSON,MI 49201. US FISH & WILDLIFE SERV,E LANSING FIELD OFF,E LANSING,MI 48823. NATL FISHERIES CONTAMINANT RES CTR,NATL BIOL SURVEY,COLUMBIA,MO 65201. RP GIESY, JP (reprint author), MICHIGAN STATE UNIV,PESTICIDE RES CTR,DEPT FISHERIES & WILDLIFE,E LANSING,MI 48824, USA. RI Mora, Miguel/B-1344-2009; Jones, Paul/O-2046-2015 OI Jones, Paul/0000-0002-7483-5380 FU NIEHS NIH HHS [ES-04911] NR 76 TC 53 Z9 54 U1 0 U2 9 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 AUG PY 1994 VL 27 IS 2 BP 213 EP 223 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT637 UT WOS:A1994NT63700010 PM 8060165 ER PT J AU JIBSON, RW PRENTICE, CS BORISSOFF, BA ROGOZHIN, EA LANGER, CJ AF JIBSON, RW PRENTICE, CS BORISSOFF, BA ROGOZHIN, EA LANGER, CJ TI SOME OBSERVATIONS OF LANDSLIDES TRIGGERED BY THE 29-APRIL-1991 RACHA EARTHQUAKE, REPUBLIC-OF-GEORGIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID PLATE MOTIONS; CALIFORNIA; CAUCASUS; EXAMPLE; TURKEY AB On 29 April 1991 an Ms 7.0 earthquake occurred in the Racha region of the Great Caucasus Mountains in north-central Republic of Georgia. The earthquake occurred on a thrust fault striking roughly east-west and dipping about 20-degrees to 45-degrees northward; focal depth was 17 +/- 2 km. We observed no surface fault rupture, but the earthquake caused extensive structural damage to the many unreinforced stone buildings in the area, and at least 114 people were killed. Many landslides were triggered in a 2500-km2 epicentral area, and they caused much of the structural damage and at least half the fatalities. We observed the following six types of landslides (in order of decreasing abundance): rock falls, debris slides, slumps, earth slides, rock block slides, and rock avalanches. The types of landslides triggered by the earthquake are controlled primarily by lithology and geologic structure. Enigmatic landslide processes associated with this earthquake include (1) delays of several days between earthquake shaking and significant landslide movement, probably caused by changes in groundwater conditions; (2) small co-seismic displacement of landslides active at the time of the earthquake, a possible result of viscoplastic damping of the seismic shaking; and (3) somewhat unusual failure geometries related to local topography and geologic structure. C1 US GEOL SURVEY,MENLO PK,CA 94025. ACAD SCI MOSCOW,INST PHYS EARTH,MOSCOW 123810,RUSSIA. RP JIBSON, RW (reprint author), US GEOL SURVEY,DENVER,CO 80225, USA. NR 28 TC 25 Z9 29 U1 0 U2 6 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 1994 VL 84 IS 4 BP 963 EP 973 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800001 ER PT J AU MORI, J FILSON, J CRANSWICK, E BORCHERDT, R AMIRBEKIAN, R AHARONIAN, V HACHVERDIAN, L AF MORI, J FILSON, J CRANSWICK, E BORCHERDT, R AMIRBEKIAN, R AHARONIAN, V HACHVERDIAN, L TI MEASUREMENTS OF P AND S-WAVE FRONTS FROM THE DENSE 3-DIMENSIONAL ARRAY AT GARNI, ARMENIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SITE; AFTERSHOCKS; EARTHQUAKE; CALIFORNIA; COHERENCE AB The P- and S-wave arrivals from local earthquakes were studied using an array of 10 three-component instruments in and around a tunnel at Garni Observatory, Armenia. The array has a three-dimensional configuration with lateral dimensions of 300 to 500 m and a depth extent of 100 m. Estimates of the horizontal and vertical components of slowness for P and S wave fronts were used to determine the angles of approach and the propagation velocity. The results showed that the region around the array has low average velocities for both the P (1.43 km/sec) and S (0.61 km/sec) waves, so wave fronts approach the array at steep angles of incidence. Waveforms from one event show clear reflections from the free surface for both P and S waves. The timing of these reflections gives the velocity variation with depth within the array. We estimated a P velocity of 0.33 km/sec within a few meters of the surface, increasing to several kilometers per second for the deepest portion of the array. Local site variations can greatly complicate the high-frequency waveforms, even for tunnel stations in bedrock. The S waves exhibit stronger site dependent waveforms and time delays than do the P waves. C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. NATL SURVEY SEISM PROTECT,YEREVAN,ARMENIA. ARMENIAN ACAD SCI,YEREVAN,ARMENIA. RP MORI, J (reprint author), US GEOL SURVEY,PASADENA,CA 91106, USA. NR 12 TC 10 Z9 10 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 1994 VL 84 IS 4 BP 1089 EP 1096 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800009 ER PT J AU ANDREWS, DJ AF ANDREWS, DJ TI DYNAMIC GROWTH OF MIXED-MODE SHEAR CRACKS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID PROPAGATION; RUPTURE; FRICTION; FAULT AB A pure mode II (in-plane) shear crack cannot propagate spontaneously at a speed between the Rayleigh and S-wave speeds, but a three-dimensional (3D) or two-dimensional (2D) mixed-mode shear crack can propagate in this range, being driven by the mode III (antiplane) component. Two different analytic solutions have been proposed for the mode II component in this case. The first is the solution valid for crack speed less than the Rayleigh speed. When applied above the Rayleigh speed, it predicts a negative stress intensity factor, which implies that energy is generated at the crack tip. Burridge proposed a second solution, which is continuous at the crack tip, but has a singularity in slip velocity at the Rayleigh wave. Spontaneous propagation of a mixed-mode rupture has been calculated with a slip-weakening friction law, in which the slip velocity vector is colinear with the total traction vector. Spontaneous trans-Rayleigh rupture speed has been found. The solution depends on the absolute stress level. The solution for the in-plane component appears to be a superposition of smeared-out versions of the two analytic solutions. The proportion of the first solution increases with increasing absolute stress. The amplitude of the negative in-plane traction pulse is less than the absolute final sliding traction, so that total in-plane traction does not reverse. The azimuth of the slip velocity vector varies rapidly between the onset of slip and the arrival of the Rayleigh wave. The variation is larger at smaller absolute stress. RP ANDREWS, DJ (reprint author), US GEOL SURVEY,MENLO PK,CA 94026, USA. NR 17 TC 28 Z9 28 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 1994 VL 84 IS 4 BP 1184 EP 1198 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800017 ER PT J AU JOYNER, WB SPUDICH, P AF JOYNER, WB SPUDICH, P TI INCLUDING NEAR-FIELD TERMS IN THE ISOCHRONE INTEGRATION METHOD FOR APPLICATION TO FINITE-FAULT OR KIRCHHOFF BOUNDARY INTEGRAL PROBLEMS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EARTHQUAKE AB In many types of seismological and engineering problems, it is necessary to perform a surface integral involving a Green's function having either a source or receiver point on the surface. For far-field terms of the Green's function, it is well known that the surface integral can be reduced to a line integral, yielding a considerable computational advantage. In this work we show that a similar transformation to a line integral can be made for the near-field terms when the Green's function for a uniform whole space. The necessary condition is that the various terms in the Green's function can be transformed into sums of nondispersive pulses. We accomplish this for near-field terms in a whole space by repeatedly time-differentiating the terms. RP JOYNER, WB (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 13 TC 2 Z9 2 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 1994 VL 84 IS 4 BP 1260 EP 1265 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800023 ER PT J AU AMMON, CJ LAY, T VELASCO, AA VIDALE, JE AF AMMON, CJ LAY, T VELASCO, AA VIDALE, JE TI ROUTINE ESTIMATION OF EARTHQUAKE SOURCE COMPLEXITY - THE 18 OCTOBER 1992 COLOMBIAN EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID RUPTURE PROCESS AB We describe two methods, suitable for routine application to teleseismic recordings, that characterize the time history of seismic events. Stacking short-period signals from large regional arrays provides stable estimates of high-frequency radiation from the source, and an empirical Green's function deconvolution procedure extracts reliable, broadband time functions suitable for analysis of faulting complexity and the spatio-temporal extent of rupture. Combined, these procedures characterize the source radiation of large events (M(S) > 7) between 200- and 0.5-sec periods. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP AMMON, CJ (reprint author), UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 9 TC 17 Z9 17 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 1994 VL 84 IS 4 BP 1266 EP 1271 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800024 ER PT J AU HOSTETLER, SW AF HOSTETLER, SW TI HYDROLOGIC AND ATMOSPHERIC MODELS - THE (CONTINUING) PROBLEM OF DISCORDANT SCALES SO CLIMATIC CHANGE LA English DT Editorial Material ID GENERAL-CIRCULATION MODEL; CLIMATE MODELS; LAND-SURFACE; SIMULATION; BOUNDARY RP HOSTETLER, SW (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. NR 27 TC 49 Z9 53 U1 0 U2 3 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 AUG PY 1994 VL 27 IS 4 BP 345 EP 350 DI 10.1007/BF01096266 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA NW169 UT WOS:A1994NW16900001 ER PT J AU SHERWOOD, CR BUTMAN, B CACCHIONE, DA DRAKE, DE GROSS, TF STERNBERG, RW WIBERG, PL WILLIAMS, AJ AF SHERWOOD, CR BUTMAN, B CACCHIONE, DA DRAKE, DE GROSS, TF STERNBERG, RW WIBERG, PL WILLIAMS, AJ TI SEDIMENT-TRANSPORT EVENTS ON THE NORTHERN CALIFORNIA CONTINENTAL-SHELF DURING THE 1990-1991 STRESS EXPERIMENT SO CONTINENTAL SHELF RESEARCH LA English DT Article ID BOTTOM BOUNDARY-LAYER; OCEAN DYNAMICS EXPERIMENT; WAVE-CURRENT INTERACTION; SEASONAL DIFFERENCES; BED ROUGHNESS; PREDICTIONS; TEMPERATURE; VARIABILITY; STORM; RIVER AB Measurements of currents and light transmission were made at bottom tripods and moorings arrayed across the northern California continental shelf along the Coastal Ocean Dynamics Experiment (CODE) ''C'' transect as part of the 1990-1991 Sediment Transport Events on Shelves and Slopes (STRESS) experiment. In combination with meteorological and wave data from the National Data Buoy Center Buoy 46013, these measurements provide information about the physical forcing and resultant resuspension and transport of bottom material between 21 November and 8 March. Sixteen events were identified in the wave, wind and current-meter records for this period. Only two were local storms with southerly winds, but they caused about half of the seasonal net transport. Seven were swell events that combined long-period waves generated by distant storms with local currents. At the 90-m site, swells interacted with the mean northward flow to produce northward transport. During six northerly wind events, upwelling-favorable winds often were sufficient to slow or reverse the mean northward flow and thus caused southward transport. A single current event, which produced moderate southward transport, was observed at the 130-m site. Net transport during the winter experiment was offshore at all sites, northward at the inner- and mid-shelf sites, but southward at the outer-shelf site. The results suggest that local storms with southerly winds may dominate seasonal transport, as on the Washington shelf, but significant transport also can occur during fair weather and during periods of northerly winds. C1 US GEOL SURVEY,WOODS HOLE,MA 02543. US GEOL SURVEY,MENLO PK,CA 94025. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22903. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. BATTELLE MEM INST,MARINE SCI LAB,SEQUIM,WA 98382. SKIDAWAY INST OCEANOG,SAVANNAH,GA 31416. RP SHERWOOD, CR (reprint author), UNIV WASHINGTON,SCH OCEANOG,SEATTLE,WA 98195, USA. NR 50 TC 87 Z9 91 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG-SEP PY 1994 VL 14 IS 10-11 BP 1063 EP 1099 DI 10.1016/0278-4343(94)90029-9 PG 37 WC Oceanography SC Oceanography GA NY006 UT WOS:A1994NY00600002 ER PT J AU WIBERG, PL DRAKE, DE CACCHIONE, DA AF WIBERG, PL DRAKE, DE CACCHIONE, DA TI SEDIMENT RESUSPENSION AND BED ARMORING DURING HIGH BOTTOM STRESS EVENTS ON THE NORTHERN CALIFORNIA INNER CONTINENTAL-SHELF - MEASUREMENTS AND PREDICTIONS SO CONTINENTAL SHELF RESEARCH LA English DT Article ID COMBINED WAVE; PARTICLE-SIZE; CURRENT FLOWS; SHEAR-STRESS; COEFFICIENT; DYNAMICS; RIPPLES; STORMS AB Geoprobe bottom tripods were deployed during the winter of 1990-1991 on the northern California inner continental shelf as part of the STRESS field experiment. Transmissometer measurements of light beam attenuation were made at two levels and current velocity was measured at four levels in the bottom 1.2 m of water. Intervals of high measured bottom wave velocity were generally correlated with times of both high attenuation and high attenuation gradient in the bottom meter of the water column. Measured time series of light attenuation and attenuation gradient are compared to values computed using a modified version of the SMITH [(1977) The sea, Vol. 6, Wiley-Interscience, New York, pp. 539-5771 steady wave-current bottom-boundary-layer model. Size-dependent transmissometer calibrations, which show significantly enhanced attenuation with decreasing grain size, are used to convert calculated suspended sediment concentration to light attenuation. The finest fractions of the bed, which are the most easily suspended and attenuate the most light, dominate the computed attenuation signal although they comprise only about 5-7% of the bed sediment. The calculations indicate that adjusting the value of the coefficient gamma0 in the expression for near-bed sediment concentration cannot in itself give both the correct magnitudes of light attenuation and attenuation gradient. To supply the volumes of fine sediment computed to be in suspension during peak events, even with values of gamma0 as low as 5 x 10(-5), requires suspension of particles from unreasonably large depths in the bed. A limit on the depth of sediment availability is proposed as a correction to suspended sediment calculations. With such a limit, reasonable attenuation values are computed with gamma0 almost-equal-to 0.002. The effects of limiting availability and employing a higher gamma0 are to reduce the volume of the finest sediment in suspension and to increase the suspended volumes of the coarser fractions. As a consequence, the average size and settling velocity of suspended sediment increases as bottom shear stress increases, with accompanying increases in near-bed concentration gradients. Higher concentration gradients produce larger stratification effects, particularly near the top of the wave boundary layer at times when wave shear velocities are high and current shear velocities are low. These are the conditions under which maximum attenuation gradients are observed. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP WIBERG, PL (reprint author), UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903, USA. NR 40 TC 136 Z9 138 U1 1 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG-SEP PY 1994 VL 14 IS 10-11 BP 1191 EP 1219 DI 10.1016/0278-4343(94)90034-5 PG 29 WC Oceanography SC Oceanography GA NY006 UT WOS:A1994NY00600007 ER PT J AU TROWBRIDGE, JH BUTMAN, B LIMEBURNER, R AF TROWBRIDGE, JH BUTMAN, B LIMEBURNER, R TI CHARACTERISTICS OF THE NEAR-BOTTOM SUSPENDED SEDIMENT FIELD OVER THE CONTINENTAL-SHELF OFF NORTHERN CALIFORNIA BASED ON OPTICAL ATTENUATION MEASUREMENTS DURING STRESS AND SMILE SO CONTINENTAL SHELF RESEARCH LA English DT Article ID NEPHELOID LAYERS; BOUNDARY-LAYER; OREGON; OCEAN AB Time-series measurements of current velocity, optical attenuation and surface wave intensity obtained during the Sediment Transport Events on Shelves and Slopes (STRESS) experiments, combined with shipboard measurements of conductivity, temperature and optical attenuation obtained during the Shelf Mixed Layer Experiment (SMILE), provide a description of the sediment concentration field over the central and outer shelf off northern California. The questions addressed are: (1) existence and characteristics of bottom nepheloid layers and their relationship to bottom mixed layers; (2) characteristics of temporal fluctuations in sediment concentration and their relationship to waves and currents; (3) spatial scales over which suspended sediment concentrations vary horizontally; and (4) vertical distribution of suspended sediment. C1 US GEOL SURVEY,WOODS HOLE,MA 02543. RP TROWBRIDGE, JH (reprint author), WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543, USA. NR 23 TC 7 Z9 7 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG-SEP PY 1994 VL 14 IS 10-11 BP 1257 EP 1272 DI 10.1016/0278-4343(94)90037-X PG 16 WC Oceanography SC Oceanography GA NY006 UT WOS:A1994NY00600010 ER PT J AU CACCHIONE, DA DRAKE, DE FERREIRA, JT TATE, GB AF CACCHIONE, DA DRAKE, DE FERREIRA, JT TATE, GB TI BOTTOM STRESS ESTIMATES AND SAND TRANSPORT ON NORTHERN CALIFORNIA INNER CONTINENTAL-SHELF SO CONTINENTAL SHELF RESEARCH LA English DT Article ID BOUNDARY-LAYER; COMBINED WAVE; SEDIMENT; STORM; BED; DYNAMICS; MODEL; FLOWS AB Measurements of velocities and light transmission in the bottom boundary layer on the continental shelf off northern California demonstrate the importance of storms in the transport of sediment along the coast and offshore in this region. Time-series estimates of bottom stress obtained from a combined wave-current bottom boundary layer model in which wave and current measurements from the Geoprobe tripod were used as input show high stress values of 10 dynes cm-2 during two distinct storm events in early February and early March, 1991. These stresses induce significant offshore sediment transport, achieving maximum values of about 0.5 g cm-1 s-1. The net transport over the entire measurement period from 30 January 1991 to 13 March 1991 was along the coast toward the north and offshore. This transport pattern explains slow migration of low amplitude, broad crescentic dunes along and across this portion of the inner continental shelf. RP CACCHIONE, DA (reprint author), US GEOL SURVEY,BRANCH PACIFIC MARINE GEOL,MS-999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 24 TC 19 Z9 19 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG-SEP PY 1994 VL 14 IS 10-11 BP 1273 EP 1289 DI 10.1016/0278-4343(94)90038-8 PG 17 WC Oceanography SC Oceanography GA NY006 UT WOS:A1994NY00600011 ER PT J AU ARRIBAS, A TOSDAL, RM AF ARRIBAS, A TOSDAL, RM TI ISOTOPIC COMPOSITION OF PB IN ORE-DEPOSITS OF THE BETIC CORDILLERA, SPAIN - ORIGIN AND RELATIONSHIP TO OTHER EUROPEAN DEPOSITS SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID LEAD-ISOTOPE; EXTENSIONAL COLLAPSE; SOUTHERN SPAIN; GIBRALTAR ARC; SHEAR ZONE; MINERALIZATION; GENESIS; FRANCE; GEOCHEMISTRY; EVOLUTION AB The Betic Cordillera in southern Spain is a complex Alpine fold belt that resulted from the Cretaceous through Cenozoic collision of Africa with Europe. The region is illustrative of one of the characteristics of the Alpine-Mediterranean orogen: the occurrence over a limited area of mineral deposits with a wide variety of host rocks, mineralization ages, and styles. The metamorphic basement in the Betic zone is characterized by a nappe structure of superimposed tectonostratigraphic units and consists of lower Paleozoic to Lower Triassic clastic metasedimentary rocks. This is overlain by Middle to Upper Triassic platform carbonate rocks with abundant strata-bound F-Pb-Zn-(Ba) deposits (e.g., Sierra de Gador, Sierra Alhamilla). Cretaceous to Paleogene subduction-related compression in southeastern Spain was followed by Miocene postcollisional extension and resulted in the formation of the Almeria-Cartagena volcanic belt and widespread hydrothermal activity and associated polymetallic mineralization. Typical Miocene hydrothermal deposits include volcanic-hosted Au (e.g., Rodalquilar) and Ag-rich base metal (e.g., Cabo de Gata, Mazarron) deposits as well as complex polymetallic veins, mantos, and irregular replacement bodies which are hosted by Paleozoic and Mesozoic metamorphic rocks and Neogene sedimentary and volcanic rocks (e.g., Cartagena, Sierra Almagrera, Sierra del Aguilon, Loma de Bas). Lead isotope compositions were measured on sulfide samples from nine ore districts and from representative fresh samples of volcanic and basement rock types of the region. The results have been used to evaluate ore-forming processes in southeastern Spain with emphasis on the sources of metals. During a Late Triassic mineralizing event, Pb was leached from Paleozoic clastic metasedimentary rocks and incorporated in galena in strata-bound F-Pb-Zn-(Ba) deposits (Pb-206/Pb-204 = 18.332 +/- 12, Pb-207/Pb-204 = 15.672 +/- 12, Pb-208/Pb-204 = 38.523 +/- 46). The second episode of mineralization was essentially contemporaneous (late Miocene) throughout the region and did not involve remobilization of less radiogenic Triassic ore Pb. Lead isotope data indicate a dominantly Paleozoic metasedimentary source for polymetallic vein- and manto-type deposits that formed by hydrothermal circulation through the Betic basement, driven by Miocene intrusions (Pb-206/Pb-204 = 18.860 +/- 20, Pb-207/Pb-204 = 15.685 +/- 9, Pb-208/Pb-204 = 39.026 +/- 37). Lead in Au-(Cu-Te-Sn) ores is isotopically indistinguishable from that of the calc-alkalic volcanic host (Pb-206/Pb-204 = 18.860 +/- 9, Pb-207/Pb-204 = 15.686 +/- 8, Pb-208/Pb-204 = 38.940 +/- 27). In contrast, the Pb in volcanic-hosted Pb-Zn-Cu-(Ag-Au) veins was derived from Paleozoic metamorphic and Miocene volcanic rocks (Pb-206/Pb-204 = 18.786 +/- 5, Pb-207/Pb-204 = 15.686 +/- 2, Pb-208/Pb-204 = 38.967 +/- 9). A comparison of the Pb isotope data from southeastern Spain with published data from selected Pb-Zn deposits in southern Europe (including Les Malines, L'Argentiere, and the Alpine, Iglesiente-Sulcis, and Montagne Noire districts) indicates the importance of a meta-sedimentary basement as a common source of ore Pb. C1 UNIV MICHIGAN,DEPT GEOL SCI,ANN ARBOR,MI 48109. US GEOL SURVEY,MENLO PK,CA 94025. NR 78 TC 54 Z9 54 U1 2 U2 9 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 1994 VL 89 IS 5 BP 1074 EP 1093 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PL459 UT WOS:A1994PL45900006 ER PT J AU GUILLETTE, LJ GROSS, TS MASSON, GR MATTER, JM PERCIVAL, HF WOODWARD, AR AF GUILLETTE, LJ GROSS, TS MASSON, GR MATTER, JM PERCIVAL, HF WOODWARD, AR TI DEVELOPMENTAL ABNORMALITIES OF THE GONAD AND ABNORMAL SEX-HORMONE CONCENTRATIONS IN JUVENILE ALLIGATORS FROM CONTAMINATED AND CONTROL LAKES IN FLORIDA SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE ALLIGATORS; ESTROGENS; GONADAL ABNORMALITIES; REPTILES; TESTOSTERONE ID PLASMA-CORTICOSTERONE LEVELS; AMERICAN ALLIGATOR; NEONATAL EXPOSURE; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN-TREATED RATS; PITUITARY-RESPONSIVENESS; ADRENAL STEROIDOGENESIS; STEROID-HORMONES; EGGS; DIETHYLSTILBESTROL; MISSISSIPPIENSIS AB The reproductive developments of alligators from a contaminated and a control lake in central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed due to an extensive spill of dicofol and DDT or its metabolites. These compounds can act as estrogens. Contaminants in the lake also have been derived from extensive agricultural activities around the lake that continue today and a sewage treatment facility associated with the city of Winter Garden, Florida. We examined the hypothesis that an estrogenic contaminant has caused the current failure in recruitment of alligators on Lake Apopka. Supporting data include the following: At 6 months of age, female alligators from Lake Apopka had plasma estradiol-17 beta concentrations almost two times greater than normal females from the control lake, Lake Woodruff. The Apopka females exhibited abnormal ovarian morphology with large numbers of polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly depressed plasma testosterone concentrations comparable to levels observed in normal Lake Woodruff females but more than three times lower than normal Lake Woodruff males. Additionally, males from Lake Apopka had poorly organized testes and abnormally small phalli. The differences between lakes and sexes in plasma hormone concentrations of juvenile alligators remain even after stimulation with luteinizing hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been permanently modified in ovo, so that normal steroidogenesis is not possible, and thus normal sexual maturation is unlikely. C1 UNIV FLORIDA,INTERDISCIPLINARY CTR BIOTECHNOL RES,REPROD ANAL LAB,BEECS,GAINESVILLE,FL 32611. US FISH & WILDLIFE SERV,CONTAMINANTS BRANCH,BRUNSWICK,GA 31520. UNIV FLORIDA,DEPT WILDLIFE & RANGE SCI,NATL BIOL SURVEY,GAINESVILLE,FL 32611. FLORIDA GAME & FRESH WATER FISH COMMISS,GAINESVILLE,FL 32601. RP GUILLETTE, LJ (reprint author), UNIV FLORIDA,DEPT ZOOL,GAINESVILLE,FL 32611, USA. NR 62 TC 747 Z9 768 U1 5 U2 127 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD AUG PY 1994 VL 102 IS 8 BP 680 EP 688 DI 10.2307/3432198 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA PC373 UT WOS:A1994PC37300012 PM 7895709 ER PT J AU WUNDERLICH, RC WINTER, BD MEYER, JH AF WUNDERLICH, RC WINTER, BD MEYER, JH TI RESTORATION OF THE ELWHA RIVER ECOSYSTEM SO FISHERIES LA English DT Article AB Historically, the Elwha River in western Washington was renowned for an abundance and diversity of anadromous salmonids. Most of the river system lies within Olympic National Park and remains in pristine condition, but two dams in the lower river have blocked all anadromous fish for more than 80 years. To restore the Elwha's historic fishery resources and resolve an impasse about federal licensing of the dams, the U.S. Congress passed the Elwha River Ecosystem and Fisheries Restoration Act in 1992. The act required an analysis of alternatives (dam retention with fish passage facilities v dam removal) to achieve full ecosystem and fishery restoration. Analysis indicates that removal of both dams is the only option that will achieve full restoration, but dam removal and fish restoration efforts could span 20 years and cost from US$147 million to US$203 million. Although fish restoration poses problems because of limited native runs, sediment management presents the most significant environmental challenge and cost. Nevertheless, a unique opportunity to fully restore the ecosystem of a major anadromous-salmonid-producing river is at hand. RP WUNDERLICH, RC (reprint author), US FISH & WILDLIFE SERV,WESTERN WASHINGTON FISHERY RESOURCE OFF,2625 PARKMONT LANE,OLYMPIA,WA 98502, USA. NR 0 TC 39 Z9 39 U1 2 U2 45 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD AUG PY 1994 VL 19 IS 8 BP 11 EP 19 DI 10.1577/1548-8446(1994)019<0011:ROTERE>2.0.CO;2 PG 9 WC Fisheries SC Fisheries GA NY867 UT WOS:A1994NY86700004 ER PT J AU FINKELMAN, RB AF FINKELMAN, RB TI MODES OF OCCURRENCE OF POTENTIALLY HAZARDOUS ELEMENTS IN COAL - LEVELS OF CONFIDENCE SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Trace Element Transformations in Coat-Fired Power Systems CY APR 19-22, 1993 CL SCOTTSDALE, AZ AB The modes of occurrence of the potentially hazardous elements in coal will be of significance in any attempt to reduce their mobilization due to coal combustion. Antimony and selenium may be present in solid solution in pyrite, as minute accessory sulfides dispersed throughout the organic matrix, or in organic association. Because of these modes of occurrence it is anticipated that less than 50% of these elements will be routinely removed by conventional coal cleaning procedures. Arsenic and mercury occur primarily in late-stage coarse-grained pyrite therefore physical coal cleaning procedures should be successful in removing substantial proportions of these elements. Cadmium occurs in sphalerite and lead in galena. Both of these minerals exhibit a wide range of particle sizes and textural relations. Depending on the particle size and textural relations, physical coal cleaning may remove as little as 25% of these elements or as much as 75%. Manganese in bituminous coal occurs in carbonates, especially siderite. Physical coal cleaning should remove a substantial proportion of this element. More information is needed to elucidate the modes of occurrence of beryllium, chromium, cobalt, and nickel. RP FINKELMAN, RB (reprint author), US GEOL SURVEY,NATL CTR,COAL ECOL BRANCH,MS 956,RESTON,VA 22092, USA. NR 60 TC 264 Z9 323 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD AUG PY 1994 VL 39 IS 1-3 BP 21 EP 34 DI 10.1016/0378-3820(94)90169-4 PG 14 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA PG937 UT WOS:A1994PG93700003 ER PT J AU WANG, JW TATSUMOTO, M LI, XB PREMO, WR CHAO, ECT AF WANG, JW TATSUMOTO, M LI, XB PREMO, WR CHAO, ECT TI A PRECISE TH-232-PB-208 CHRONOLOGY OF FINE-GRAINED MONAZITE - AGE OF THE BAYAN OBO REE-FE-NB ORE DEPOSIT, CHINA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT Symposium on Topics in Global Geochemistry, in Honor of Clair C Patterson CY DEC 03-04, 1993 CL PASADENA, CA ID U-PB; INNER-MONGOLIA; ND; SR AB We have obtained precise Th-Pb internal isochron ages on monazite and bastnaesite for the world's largest known rare earth elements (REE)-Fe-Nb ore deposit, the Bayan Obo of Inner Mongolia, China. The monazite samples, collected from the carbonate-hosted ore zone, contain extremely small amounts of uranium (less than 10 ppm) but up to 0.7% ThO2. Previous estimates of the age of mineralization ranged from 1.8 to 0.255 Ga. Magnetic fractions of monazite and bastnaesite samples (<60-mu m size) showed large ranges in Th-232/Pb-204 values (900-400,000) and provided precise Th-Pb internal isochron ages for paragenetic monazite mineralization ranging from 555 to 398 Ma within a few percent error (0.8% for two samples). These results are the first indication that REE mineralization within the giant Bayan Obo ore deposit occurred over a long period of time. The initial lead isotopic compositions (low Pb-206/Pb-204 and high Pb-208/Pb-204) and large negative epsilon(Nd) values for Bayan Obo ore minerals indicate that the main source(s) for the ores was the lower crust which was depleted in uranium, but enriched in thorium and light rare earth elements for a long period of time. Zircon from a quartz monzonite, located 50 km south of the ore complex and thought to be related to Caledonian subduction, gave an age of 451 Ma, within the range of monazite ages. Textural relations together with the mineral ages favor an epigenetic rather than a syngenetic origin for the orebodies. REE mineralization started around 555 Ma (disseminated monazite in the West, the Main, and south of the East Orebody), but the main mineralization (banded ores) was related to the Caledonian subduction event ca. 474-400 Ma. C1 US GEOL SURVEY,DENVER,CO 80225. US GEOL SURVEY,NATL CTR,RESTON,VA 22092. NR 35 TC 64 Z9 82 U1 2 U2 9 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 AUG PY 1994 VL 58 IS 15 BP 3155 EP 3169 DI 10.1016/0016-7037(94)90043-4 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB991 UT WOS:A1994PB99100004 ER PT J AU HINKLEY, TK AF HINKLEY, TK TI COMPOSITION AND SOURCES OF ATMOSPHERIC DUSTS IN SNOW AT 3200 METERS IN THE ST-ELIAS-RANGE, SOUTHEASTERN ALASKA, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT Symposium on Topics in Global Geochemistry, in Honor of Clair C Patterson CY DEC 03-04, 1993 CL PASADENA, CA ID GREENLAND ICE-SHEET; ROCK-FORMING METALS; SEASONAL-VARIATIONS; PARTICLES; AEROSOL; SULFATE; SEA; TRANSPORT; ELEMENTS; NITRATE AB Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also-large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (approximate to 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples. RP HINKLEY, TK (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,DENVER,CO 80225, USA. NR 57 TC 15 Z9 15 U1 1 U2 4 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 AUG PY 1994 VL 58 IS 15 BP 3245 EP 3254 DI 10.1016/0016-7037(94)90052-3 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB991 UT WOS:A1994PB99100013 ER PT J AU HINKLEY, TK LECLOAREC, MF LAMBERT, G AF HINKLEY, TK LECLOAREC, MF LAMBERT, G TI FRACTIONATION OF FAMILIES OF MAJOR, MINOR, AND TRACE-METALS ACROSS THE MELT VAPOR INTERFACE IN VOLCANIC EXHALATIONS SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT Symposium on Topics in Global Geochemistry, in Honor of Clair C Patterson CY DEC 03-04, 1993 CL PASADENA, CA ID MOUNT ST-HELENS; KILAUEA VOLCANO; SMALL PARTICLES; JANUARY 1983; EMISSIONS; ERUPTION; ELEMENTS; HAWAII; PLUMES; INCRUSTATIONS AB Chemical families of metals fractionate systematically as they pass from a silicate melt across the interface with the vapor phase and on into a cooled volcanic plume. We measured three groups of metals in a small suite of samples collected on filters from the plumes of Kilauea (Hawaii, USA), Etna (Sicily), and Merapi (Java) volcanoes. These were the major, minor, and trace metals of the alkali and alkaline earth families (K, Rb, Cs, Ca, Sr, Pa), a group of ordinarily rare metals (Cd, Cu, In, Pb, T1) that are related by their chalcophile affinities, and the radon daughter nuclides Po-210, Bi-210 and Pb-210. The measurements show the range and some details of systematic melt-vapor fractionation within and between these groups of metals. In the plumes of all three volcanoes, the alkali metals are much more abundant than the alkaline earth metals. In the Kilauea plume, the alkali metals are at least six times more abundant than the alkaline earth metals, relative to abundances in the melt; at Etna, the factor is at least 300. Fractionations within each family are, commonly, also distinctive: in the Kilauea plume, in addition to the whole alkaline earth family being depleted, the heaviest metals of the family (Sr, Pa) are progressively more depleted than the light metal Ca. In plumes of fumaroles at Merapi, K/Cs ratios were approximately three orders of magnitude smaller than found in other earth materials. This may represent the largest observed enrichment of the ''light ion lithophile'' (LIL) metals. Changes in metal ratios were seen through the time of eruption in the plumes of Kilauea and Etna. This may reflect degree of degassing of volatiles, with which metals complex, from the magma bodies. At Kilauea, the changes in fractionation were seen over about three years; fractionation within the alkaline earth family increased, and that between the two families decreased, over that time. All of the ordinarily rare chalcophile metals measured are extremely abundant in volcanic plumes, and Cd and Tl are enriched relative to the others. Indium is much more abundant in the plume of the hotspot volcano Kilauea than in the Etna plume (probably non-hotspot in character). It may be a useful indicator of the tapping of deep mantle zones, or could aid in the interpretation of reports of Pt group metals in exhalations from hot spot volcanoes. Indium in old glacial ice strata could help assess magnitude and variability of exhalations from hotspot volcanoes in past time. Strong melt-vapor fractionation of the alkali and alkaline earth metals may only be observed in plumes during quiescent degassing of volcanoes; when large amounts of ash or spatter (undifferentiated lava) enter the plume, its alkali and alkaline earth metal composition may approach that of the melt. Ratios among the chalcophile metals may not be much changed by addition of ash, because their concentrations in melt are so small, and masses of them in any plume may remain dominated by transfer across the melt-vapor interface. Radon daughter nuclides give information about state of volcanic activity at time of sampling. The precisely known origins, ultratrace detectability, decay systematics, and wide variations in volatility of these species provide information about residence times, degassing and travel histories, and identities of melt bodies in volcanic systems. C1 CEA,CNRS,MIXTE LAB,CTR FAIBLES RADIOACT,F-91190 GIF SUR YVETTE,FRANCE. RP HINKLEY, TK (reprint author), US GEOL SURVEY,MS 903,DENVER,CO 80225, USA. NR 65 TC 48 Z9 48 U1 0 U2 10 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 AUG PY 1994 VL 58 IS 15 BP 3255 EP 3263 DI 10.1016/0016-7037(94)90053-1 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB991 UT WOS:A1994PB99100014 ER PT J AU KOMOR, SC AF KOMOR, SC TI GEOCHEMISTRY AND HYDROLOGY OF A CALCAREOUS FEN WITHIN THE SAVAGE FEN WETLANDS COMPLEX, MINNESOTA, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID WATER; METALS AB Savage Fen is a wetlands complex at the base of north-facing bluffs in the Minnesota River Valley. The complex includes 27.8 hectares of calcareous fen that host rare calciphile plants whose populations are declining in Minnesota. Water and sediment compositions in the calcareous fen were studied to gain a better understanding of the hydrologic system that sustains the rare vegetation. Groundwater in the fen is a calcium-magnesium-bicarbonate type with circumneutral pH values. The groundwater composition is the result of interactions among water, dissolved and gaseous carbon species, carbonates, and ion exchangers. Shallow groundwater is distinguished from deep groundwater by smaller concentrations of chloride, sulfate, magnesium, and sodium, and larger concentrations of calcium, bicarbonate, hydrogen sulfide, and ammonium. Magnesian calcite is the prevalent carbonate in unconsolidated sedimentary fill beneath the fen and is an important source and sink for dissolved calcium, magnesium, and inorganic carbon. Calcite concentrations just below the water table are small because aerobic and anaerobic oxidation of organic matter increase the partial pressure of carbon dioxide (P(CO2)), decrease pH, and cause calcite to dissolve. Thick calcite accumulations just above the water table, in the root zone of calciphile plants, result from water table fluctuations and attendant changes in P(CO2). Groundwater beneath Savage Fen recharges in lakes and ponds south of the fen and upwells to the surface within the fen. Water at the water table is a mixture of upwelling groundwater and water near the surface that flows downslope from higher elevations in the fen. Changes in oxygen and hydrogen isotope compositions of shallow groundwater indicate that the proportion of upwelling groundwater in shallow groundwater decreases downgradient in the calcareous fen. Encroachment of reed grasses into the calcareous fen may reflect human-caused disturbances in the recharge area. RP KOMOR, SC (reprint author), US GEOL SURVEY,2280 WOODALE DR,MOUNDS VIEW,MN 55112, USA. NR 38 TC 32 Z9 33 U1 6 U2 24 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 AUG PY 1994 VL 58 IS 16 BP 3353 EP 3367 DI 10.1016/0016-7037(94)90091-4 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PE613 UT WOS:A1994PE61300004 ER PT J AU BEAUDOIN, BC FUIS, GS LUTTER, WJ MOONEY, WD MOORE, TE AF BEAUDOIN, BC FUIS, GS LUTTER, WJ MOONEY, WD MOORE, TE TI CRUSTAL VELOCITY STRUCTURE OF THE NORTHERN YUKON TANANA UPLAND, CENTRAL ALASKA - RESULTS FROM TACT REFRACTION WIDE-ANGLE REFLECTION DATA SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID CANADIAN-CORDILLERA; TERRANES; ZONES AB The Fairbanks North seismic refraction/wide-angle reflection profile, collected by the U.S. Geological Survey Trans-Alaska Crustal Transect (TACT) project in 1987, crosses the complex region between the Yukon-Tanana and Ruby terranes in interior Alaska. This region is occupied by numerous small terranes elongated in a northeast-southwest direction. These seismic data reveal a crustal velocity structure that is divided into three upper-crystal and at least two middle- to lower-crustal domains. The upper-crustal domains are delineated by two steeply dipping low-velocity anomalies that are interpreted as signatures of the Victoria Creek fault, and the Beaver Creek fault or a fault buried by the Beaver Creek fault. This tripartite upper crust extends to 8-10 km depth where a subhorizontal interface undercuts the northern and central domains. Beneath the northern domain, this interface is interpreted as the southeastwardly dipping boundary between the Tozitna and Ruby terranes. The continuation of this interface beneath the central domain suggests that it may represent the detachment or basal thrust for thin-skinned tectonic amalgamation of the terranes caught between the Yukon-Tanana and Ruby terranes. The lower crust and Moho reflection exhibit differences from north to south that define at least two lower-crystal domains, interpreted as the Yukon-Tanana and Ruby terranes. Finally, the crustal thickness along the profile is nearly uniform and ranges from 31 to 34 km. Our data suggest that after initial thin-skinned amalgamation of the various terranes, this region experienced thick-skinned tectonic reorganization via strike-slip faulting. This interpretation supports a model in which at least one strand of the Tintina fault exists in this important region of Alaska. C1 STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305. RP BEAUDOIN, BC (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. OI Fuis, Gary/0000-0002-3078-1544 NR 46 TC 14 Z9 14 U1 0 U2 0 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 1994 VL 106 IS 8 BP 981 EP 1001 DI 10.1130/0016-7606(1994)106<0981:CVSOTN>2.3.CO;2 PG 21 WC Geosciences, Multidisciplinary SC Geology GA PA140 UT WOS:A1994PA14000001 ER PT J AU CATCHINGS, RD AF CATCHINGS, RD TI UPPER-CRUSTAL STRUCTURE BENEATH THE COLUMBIA-RIVER-BASALT-GROUP, WASHINGTON - GRAVITY INTERPRETATION CONTROLLED BY BOREHOLE AND SEISMIC STUDIES - DISCUSSION SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Discussion ID PLATEAU RP CATCHINGS, RD (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. NR 11 TC 2 Z9 2 U1 0 U2 1 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 1994 VL 106 IS 8 BP 1096 EP 1101 DI 10.1130/0016-7606(1994)106<1096:UCSBTC>2.3.CO;2 PG 6 WC Geosciences, Multidisciplinary SC Geology GA PA140 UT WOS:A1994PA14000008 ER PT J AU SALTUS, RW AF SALTUS, RW TI UPPER-CRUSTAL STRUCTURE BENEATH THE COLUMBIA-RIVER-BASALT-GROUP, WASHINGTON - GRAVITY INTERPRETATION CONTROLLED BY BOREHOLE AND SEISMIC STUDIES - REPLY SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Discussion ID PLATEAU; RANGE RP SALTUS, RW (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 964,BOX 25046,DENVER,CO 80225, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 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 1994 VL 106 IS 8 BP 1102 EP 1105 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PA140 UT WOS:A1994PA14000009 ER PT J AU POAG, CW POWARS, DS POPPE, LJ MIXON, RB AF POAG, CW POWARS, DS POPPE, LJ MIXON, RB TI METEOROID MAYHEM IN OLE-VIRGINNY - SOURCE OF THE NORTH-AMERICAN TEKTITE STREWN FIELD SO GEOLOGY LA English DT Article ID SITE-612; COAST AB New seismic reflection data from Chesapeake Bay reveal a buried, 85-km-wide, 1.5-2.0-km-deep, peak-ring impact crater, carved through upper Eocene to Lower Cretaceous sedimentary strata and into underlying pre-Mesozoic crystalline basement rocks. A polymictic, late Eocene impact breccia, composed mainly of locally derived sedimentary debris (determined from four continuous cores), surrounds and partly fills the crater. Structural and sedimentary characteristics of the Chesapeake Bay crater closely resemble those of the Miocene Ries peak-ring crater in southern Germany. We speculate that the Chesapeake Bay crater is the source of the North American tektite strewn field. C1 US GEOL SURVEY,RESTON,VA 22092. RP POAG, CW (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. NR 15 TC 117 Z9 119 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 AUG PY 1994 VL 22 IS 8 BP 691 EP 694 DI 10.1130/0091-7613(1994)022<0691:MMIOVS>2.3.CO;2 PG 4 WC Geology SC Geology GA PA136 UT WOS:A1994PA13600005 ER PT J AU KEEFER, DK AF KEEFER, DK TI THE IMPORTANCE OF EARTHQUAKE-INDUCED LANDSLIDES TO LONG-TERM SLOPE EROSION AND SLOPE-FAILURE HAZARDS IN SEISMICALLY ACTIVE REGIONS SO GEOMORPHOLOGY LA English DT Article; Proceedings Paper CT 25th Binghamton Symposium in Geomorphology CY SEP 24-25, 1994 CL SUNY, BINGHAMTON, NY HO SUNY AB This paper describes a general method for determining the amount of earthquake-induced landsliding that occurs in a seismically active region over time; this determination can be used as a quantitative measure of the long-term hazard from seismically triggered landslides as well as a measure of the importance of this process to regional slope-erosion rates and landscape evolution. The method uses data from historical earthquakes to relate total volume of landslide material dislodged by an earthquake to the magnitude, M, and seismic moment, M(o), of the earthquake. From worldwide data, a linear-regression relation between landslide volume, V, and M(o) is determined as: V = M(o)/10(18.9(+/-0.13), where V is measured in m3 and M(o) is in dyn-cm. To determine the amount of earthquake-generated landsliding over time, this relation is combined with data on seismic-moment release for a particular region, which may be derived from either earthquake-history or fault-slip data. The form of the M(o)-V relation allows the rate of production of earthquake-induced landslides over time to be determined from total rate of seismic-moment release without regard to the distribution of individual events, thus simplifying and generalizing the determination. Application of the method to twelve seismically active regions, with areas ranging from 13,275 to 2,308,000 km2, shows that erosion rates from earthquake-induced landslides vary significantly from region to region. Of the regions studied, the highest rates were determined for the island of Hawaii, New Zealand, western New Guinea, and the San Francisco Bay region of California. Significantly lower rates were determined for Iran, Tibet, the Sierra Nevada-Great Basin region of California, and central Japan (for the time period from 715 AD to the present). Intermediate rates were determined for Peru, southern California, onshore California, Turkey, and central Japan (for the time period from 1586 AD to the present). To determine the relative, long-term importance of seismically triggered landslides, these erosion rates are compared to erosion rates calculated for other slope processes and to rates calculated from fluvial sediment discharge. Comparisons with other slope processes indicate that earthquake-induced landslides are the predominant agents of slope erosion on the island of Hawaii, in the San Francisco Bay region, and in western New Guinea. For Hawaii, the San Francisco Bay region, and Sierra Nevada-Great Basin region of California, the erosion rates calculated for earthquake-induced landslides also exceed the regional erosion rates calculated from fluvial sediment discharge. RP KEEFER, DK (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 0 TC 178 Z9 181 U1 1 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD AUG PY 1994 VL 10 IS 1-4 BP 265 EP 284 DI 10.1016/0169-555X(94)90021-3 PG 20 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PE617 UT WOS:A1994PE61700020 ER PT J AU SIPKIN, SA AF SIPKIN, SA TI RAPID-DETERMINATION OF GLOBAL MOMENT-TENSOR SOLUTIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHQUAKE SOURCE PARAMETERS; WAVEFORM DATA; INVERSION; SEISMICITY AB In an effort to improve data services, the National Earthquake Information Center has begun a program, in cooperation with the Incorporated Research Institutions for Seismology Data Management Center (IRIS DMC), to produce rapid estimates of the seismic moment tensor for most earthquakes with a body-wave magnitude of 5.8 or greater. Although this program is still undergoing testing and fine-tuning, an estimate of the moment tensor can usually be produced within 20 minutes of the arrival of the broadband P-waveform data from the IRIS DMC. Although the speed with which this data can be obtained varies, in many cases a solution can be obtained within two hours of the earthquake. These solutions do not vary significantly from the final solutions determined using the entire network. Because of the manner in which the data and the synthetic seismograms are aligned, the method is insensitive to the effects of timing errors, epicentral mislocation, and lateral heterogeneity in earth structure. This procedure was implemented in May 1993; the results from that month are presented here. RP SIPKIN, SA (reprint author), US GEOL SURVEY,DFC,MS 967,BOX 25046,DENVER,CO 80225, USA. NR 10 TC 48 Z9 50 U1 0 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 1 PY 1994 VL 21 IS 16 BP 1667 EP 1670 DI 10.1029/94GL01429 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PA722 UT WOS:A1994PA72200001 ER PT J AU PITT, AM HILL, DP AF PITT, AM HILL, DP TI LONG-PERIOD EARTHQUAKES IN THE LONG VALLEY CALDERA REGION, EASTERN CALIFORNIA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BENEATH; SWARM AB Most earthquake occurring near Long Valley caldera since the onset of recurring swarm activity in 1980 have the broad-band signature typical of tectonic or volcano-tectonic earthquakes with impulsive. high-frequency P and S waves. With the Mammoth Mountain earthquake swarm in mid 1989, we began detecting occasional events with a marked deficiency in energy above 5 Hz. a feature typical of long-period (LP) volcanic earthquakes. These events occur beneath the southwest flank of Mammoth Mountain at focal depths ranging from 10 to 28 km, distinctly deeper than the 2- to 10-km depth range for tectonic earthquakes in the area. The LP events occur at intervals ranging from weeks to months. Individual occurrences typically consist of several events within 2 to 5 minutes where the largest event has never been first. Magnitudes range from 0.5 to 1.8. The mid-crustal focal depths of the LP events are similar to occurrences at a number of areas with Holocene volcanism in Japan and the western United States. They may indicate the movement of magmatic fluids but do not necessarily indicate an imminent volcanic eruption. RP PITT, AM (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS-977,MENLO PK,CA 94025, USA. NR 22 TC 48 Z9 48 U1 0 U2 3 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 1 PY 1994 VL 21 IS 16 BP 1679 EP 1682 DI 10.1029/94GL01371 PG 4 WC Geosciences, Multidisciplinary SC Geology GA PA722 UT WOS:A1994PA72200004 ER PT J AU STEWART, DC ANDERSON, WL GROVER, TP LABSON, VF AF STEWART, DC ANDERSON, WL GROVER, TP LABSON, VF TI SHALLOW SUBSURFACE MAPPING BY ELECTROMAGNETIC SOUNDING IN THE 300 KHZ TO 30 MHZ RANGE - MODEL STUDIES AND PROTOTYPE SYSTEM ASSESSMENT SO GEOPHYSICS LA English DT Article ID GROUND-PENETRATING-RADAR; FIELDS AB A new instrument designed for frequency-domain sounding in the depth range 0-10 m uses short coil spacings of 5 m or less and a frequency range of 300 kHz to 30 MHz. In this frequency range, both conduction currents (controlled by electrical conductivity) and displacement currents (controlled by dielectric permittivity) are important. Several surface electromagnetic survey systems commonly used (generally with frequencies less than 60 kHz) are unsuitable for detailed investigation of the upper 5 m of the earth or, as with ground-penetrating radar, are most effective in relatively resistive environments. Most computer programs written for interpretation of data acquired with the low-frequency systems neglect displacement currents, and are thus unsuited for accurate high-frequency modeling and interpretation. New forward and inverse computer programs are described that include displacement currents in layered-earth models. The computer programs and this new instrument are used to evaluate the effectiveness of shallow high-frequency soundings based on measurement of the tilt angle and the ellipticity of magnetic fields. Forward model studies indicate that the influence of dielectric permittivity provides the ability to resolve thin layers, especially if the instrument frequency range can be extended to 50 MHz. Field tests of the instrument and the inversion program demonstrate the potential for detailed shallow mapping wherein both the resistivity and the dielectric permittivity of layers are determined. Although data collection and inversion are much slower than for low-frequency methods, additional information is obtained inasmuch as there usually is a permittivity contrast as well as a resistivity contrast at boundaries between different materials. Determination of dielectric permittivity is particularly important for hazardous waste site characterization because the presence of some contaminants may have little effect on observed resistivity but a large effect on observed permittivity. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 38 TC 26 Z9 28 U1 1 U2 5 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD AUG PY 1994 VL 59 IS 8 BP 1201 EP 1210 DI 10.1190/1.1443678 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB195 UT WOS:A1994PB19500003 ER PT J AU LUTTER, WJ CATCHINGS, RD JARCHOW, CM AF LUTTER, WJ CATCHINGS, RD JARCHOW, CM TI AN IMAGE OF THE COLUMBIA PLATEAU FROM INVERSION OF HIGH-RESOLUTION SEISMIC DATA SO GEOPHYSICS LA English DT Article ID PASSCAL OUACHITA EXPERIMENT; CRUSTAL STRUCTURE; WASHINGTON; YAKIMA AB We use a method of traveltime inversion of high-resolution seismic data to provide the first reliable images of internal details of the Columbia River Basalt Group (CRBG), the subsurface basalt/sediment interface, and the deeper sediment/basement interface. Velocity structure within the basalts, delineated on the order of 1 km horizontally and 0.2 km vertically, is constrained to within +/- 0.1 km/s for most of the seismic profile. Over 5000 observed traveltimes fit our model with an rms error of 0.018 s. The maximum depth of penetration of the basalt diving waves (truncated by underlying low-velocity sediments) provides a reliable estimate of the depth to the base of the basalt, which agrees with well-log measurements to within 0.05 km (165 ft). We use image blurring, calculated from the resolution matrix, to estimate the aspect ratio of imaged velocity anomaly widths to true widths for velocity features within the basalt. From our calculations of image blurring, we interpret low velocity zones (LVZ) within the basalts at Boylston Mountain and the Whiskey Dick anticline to have widths of 4.5 and 3 km, respectively, within the upper 1.5 km of the model. At greater depth, the widths of these imaged LVZs thin to approximately 2 km or less. We interpret these linear, subparallel, low-velocity zones imaged adjacent to anticlines of the Yakima Fold Belt to be brecciated fault zones. These fault zones dip to the south at angles between 15 to 45 degrees. C1 AMOCO PROD CO,TULSA,OK 74102. US GEOL SURVEY,MENLO PK,CA 94025. NR 24 TC 22 Z9 24 U1 0 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD AUG PY 1994 VL 59 IS 8 BP 1278 EP 1289 DI 10.1190/1.1443685 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB195 UT WOS:A1994PB19500010 ER PT J AU PAN, E AMADEI, B SAVAGE, WZ AF PAN, E AMADEI, B SAVAGE, WZ TI GRAVITATIONAL STRESSES IN LONG SYMMETRICAL RIDGES AND VALLEYS IN ANISOTROPIC ROCK SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article ID GRAVITY-INDUCED STRESSES; SMALL SLOPE; TOPOGRAPHY; MASSES AB The effect of topography and rock mass anisotropy on gravitational stresses in long isolated symmetric ridges and valleys is modeled using an analytical method proposed earlier by the first two authors. The rock mass deforms under a condition plane strain. A parametric study is presented on the effect of (1) topography, (2) orientation o anisotropy and (3) degree of anisotropy on the magnitude and distribution of gravitational stresses in transvervely isotropic rock masses planes of anisotropy striking parallel to the ridge or valley axis. It is found that compressive stresses develop near ridge crests and that tensile stresses develop in valley bottoms and valley walls. The magnitude of tie gravitational stresses is of the order of the characteristic stress rhog Absolute value of b where rho is the rock density, g is the gravitational acceleration and Absolute value of b is the height of the ridge or depth of the valley. C1 US GEOL SURVEY,DENVER,CO 80225. RP PAN, E (reprint author), UNIV COLORADO,DEPT CIVIL ENGN,BOULDER,CO 80309, USA. RI Pan, Ernian/F-4504-2011 OI Pan, Ernian/0000-0001-6640-7805 NR 23 TC 21 Z9 23 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD AUG PY 1994 VL 31 IS 4 BP 293 EP 312 DI 10.1016/0148-9062(94)90899-0 PG 20 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA NY680 UT WOS:A1994NY68000002 ER PT J AU LACHOWSKI, HM WIRTH, T MAUS, P AVERS, P AF LACHOWSKI, HM WIRTH, T MAUS, P AVERS, P TI REMOTE-SENSING AND GIS - THEIR ROLE IN ECOSYSTEM MANAGEMENT SO JOURNAL OF FORESTRY LA English DT Article C1 PACIFIC MERIDIAN RESOURCES,SALT LAKE CITY,UT. US GEOL SURVEY,WASHINGTON,DC 20242. RP LACHOWSKI, HM (reprint author), US FOREST SERV,NATIONWIDE FORESTRY APPLICAT PROGRAM,2222 W 2300 S,SALT LAKE CITY,UT 84119, USA. NR 6 TC 10 Z9 11 U1 0 U2 0 PU SOC AMER FORESTERS PI BETHESDA PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 SN 0022-1201 J9 J FOREST JI J. For. PD AUG PY 1994 VL 92 IS 8 BP 39 EP 40 PG 2 WC Forestry SC Forestry GA PA688 UT WOS:A1994PA68800020 ER PT J AU MILLER, TP CHOUET, BA AF MILLER, TP CHOUET, BA TI THE 1989-1990 ERUPTIONS OF REDOUBT VOLCANO - AN INTRODUCTION SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID ALASKA AB Redoubt Volcano, located on the west side of Cook Inlet in south-central Alaska, erupted explosively on over 20 separate occasions between December 14, 1989 and April 21, 1990. Fourteen lava domes were emplaced in the summit area, thirteen of which were subsequently destroyed. The eruption caused economic losses estimated at over $160,000,000 making this the second most costly eruption in U.S. history. This economic impact provided the impetus for a integrated comprehensive account of an erupting volcano using both modern and classical research and modern techniques which in turn led to advances in eruption monitoring and interpretation. Research on such topics as dome formation and collapse and the resulting pyroclastic flows, elutriated ash, lightning, tephra, and flooding was blended with the rapid communication of associated hazards to a large user group. The seismology successes in predicting and monitoring eruption dynamics were due in part to (1) the recognition of long-period seismic events as indicators of the readiness of the volcano to erupt, and (2) to the development of new tools that allowed the seismicity to be assessed instantaneously. Integrated studies of the petrology of erupted products and volatile content over time gave clues as to the progress of the eruption towards completion. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP MILLER, TP (reprint author), US GEOL SURVEY,ALASKA VOLCANO OBSERV,4200 UNIV DR,ANCHORAGE,AK 99508, USA. NR 33 TC 28 Z9 28 U1 0 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 AUG PY 1994 VL 62 IS 1-4 BP 1 EP 10 DI 10.1016/0377-0273(94)90025-6 PG 10 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800002 ER PT J AU TILL, AB YOUNT, ME BEVIER, ML AF TILL, AB YOUNT, ME BEVIER, ML TI THE GEOLOGIC HISTORY OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID DEPOSITS; AGE AB Redoubt Volcano is a composite cone built on continental crust at the northeast end of the Aleutian are. Magmas erupted at Redoubt are medium-K calc-alkaline basalts, andesites, and dacites. The eruptive history of the volcano can be divided into four parts: the early explosive stage, early cone-building stage, late cone-building stage, and post-glacial stage. The most silicic products of the volcano were erupted during the early explosive stage about 0.888 Ma and include pumiceous pyroclastic flow deposits, block-and-ash flow deposits, and a dome or shallow intrusive complex. Basalt and basaltic andesite lava flows and scoria and ash flows were produced during the early cone-building stage, which was underway by 0.340 Ma. During the late cone-building stage, andesitic lava flows and block-and-ash flows were emplaced. Airfall deposits produced during post-glacial eruptions are silicic andesite in composition. Since the early cone-building stage, magmas have become progressively more silicic, but none are as silicic as those in the early explosive stage. Limited Pb and Sr isotopic data suggest that Redoubt magmas were contaminated by North American continental crust. C1 UNIV BRITISH COLUMBIA,DEPT GEOL SCI,VANCOUVER V6T 1Z4,BC,CANADA. RP TILL, AB (reprint author), US GEOL SURVEY,4200 UNIV DR,ANCHORAGE,AK, USA. NR 34 TC 18 Z9 18 U1 0 U2 5 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 1994 VL 62 IS 1-4 BP 11 EP 30 DI 10.1016/0377-0273(94)90026-4 PG 20 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800003 ER PT J AU POWER, JA LAHR, JC PAGE, RA CHOUET, BA STEPHENS, CD HARLOW, DH MURRAY, TL DAVIES, JN AF POWER, JA LAHR, JC PAGE, RA CHOUET, BA STEPHENS, CD HARLOW, DH MURRAY, TL DAVIES, JN TI SEISMIC EVOLUTION OF THE 1989-1990 ERUPTION SEQUENCE OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article AB Redoubt Volcano in south-central Alaska erupted between December 1989 and June 1990 in a sequence of events characterized by large tephra eruptions, pyroclastic flows, lahars and debris flows, and episodes of dome growth. The eruption was monitored by a network of five to nine seismic stations located 1 to 22 km from the summit crater. Notable features of the eruption seismicity include :(1) small long-period events beginning in September 1989 which increased slowly in number during November and early December; (2) an intense swarm of long-period events which preceded the initial eruptions on December 14 by 23 hours; (3) shallow swarms (0 to 3 km) of volcano-tectonic events following each eruption on December 15; (4) a persistent cluster of deep (6 to 10 km) volcano-tectonic earthquakes initiated by the eruptions on December 15, which continued throughout and beyond the eruption; (5) an intense swarm of long-period events which preceded the eruptions on January 2; and (6) nine additional intervals of increased long-period seismicity each of which preceded a tephra eruption. Hypocenters of volcano-tectonic earthquakes suggest the presence of a magma source region at 6-10 km depth. Earthquakes at these depths were initiated by the tephra eruptions on December 15 and likely represent the readjustment of stresses in the country rock associated with the removal of magma from these depths. The locations and time-history of these earthquakes coupled with the eruptive behavior of the volcano suggest this region was the source of most of the erupted material during the 1989-1990 eruption. This source region appears to be connected to the surface by a narrow pipe-like conduit as inferred from the hypocenters of volcano-tectonic earthquakes. Concentrations of shallow volcano-tectonic earthquakes followed each of the tephra eruptions on December 15; these shocks may represent stress readjustment in the wall rock related to the removal of magma and volatiles at these depths. This shallow zone was the source area of the majority of long-period seismicity through the remainder of the eruption. The long-period seismicity likely reflects the pressurization of the shallow portions of the magmatic system. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661. RP POWER, JA (reprint author), UNIV ALASKA,INST GEOPHYS,US GEOL SURVEY,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775, USA. NR 40 TC 93 Z9 94 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 AUG PY 1994 VL 62 IS 1-4 BP 69 EP 94 DI 10.1016/0377-0273(94)90029-9 PG 26 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800006 ER PT J AU CHOUET, BA PAGE, RA STEPHENS, CD LAHR, JC POWER, JA AF CHOUET, BA PAGE, RA STEPHENS, CD LAHR, JC POWER, JA TI PRECURSORY SWARMS OF LONG-PERIOD EVENTS AT REDOUBT VOLCANO (1989-1990), ALASKA - THEIR ORIGIN AND USE AS A FORECASTING TOOL SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT ST-HELENS; FLUID-DRIVEN CRACK; SOURCE MODEL; TREMOR; EARTHQUAKES; MECHANISM; KILAUEA; WASHINGTON; ERUPTION; HAWAII AB During the eruption of Redoubt Volcano from December 1989 through April 1990, the Alaska Volcano Observatory issued advance warnings of several tephra eruptions based on changes in seismic activity related to the occurrence of precursory swarms of long-period (LP) seismic events (dominant period of about 0.5 s). The initial eruption on December 14 occurred after 23 years of quiescence and was heralded by a 23-hour swarm of LP events that ended abruptly with the eruption. After a series of vent-clearing explosions over the next few days, dome growth began on December 21. Another swarm, with LP events similar to those of the first, began on the 26th and ended in a major tephra eruption on January 2. Eruptions continued over the next two weeks and then ceased until February 15, when a large eruption initiated a long phase of repetitive dome-building and dome-destroying episodes that continued into April. Warnings were issued before the major events on December 14 and January 2, but as the eruptive sequence continued after January 2, the energy of the swarms decreased and forecasting became more difficult. A significant but less intense swarm preceded the February 15 eruption, which was not forecast. This eruption destroyed the only seismograph on the volcanic edifice and stymied forecasting until March 4, when the first of three new stations was installed within 3 km of the active vent. From March 4 to the end of the sequence on April 21, there were eight eruptions, six of which were preceded by detectable swarms of LP events. Although weak, these swarms provided the basis for warnings issued before the eruptions on March 23 and April 6. The initial swarm on December 13 had the following features: (1) short duration (23 hours); (2) a rapidly accelerating rate of seismic energy release Over the first 18 hours of the swarm, followed by a decline of activity during the 5 hours preceding the eruption; (3) a magnitude range from -0.4 to 1.6; (4) nearly identical LP signatures with a dominant period near 0.5 s; (5) dilatational first motions everywhere; and (6) a stationary source location at a depth of 1.4 km beneath the crater. This occurrence of long-period events suggests a model involving the interaction of magma with groundwater in which magmatic gases, steam and water drive a fixed conduit at a stationary point throughout the swarm. The initiation of that sequence of events is analogous to the failure of a pressure-relief valve connecting a lower, supercharged magma-dominated reservoir to a shallow hydrothermal system. A three-dimensional model of a vibrating fluid-filled crack recently developed by Chouet is found to be compatible with the seismic data and yields the following parameters for the LP source: crack length, 280-380 m; crack width, 140-190 m; crack thickness, 0.05-0.20 m; crack stiffness, 100-200; sound speed of fluid, 0.8-1.3 km/s; compressional-wave speed of rock, 5.1 km/s; density ratio of fluid to rock, approximate to 0.4; and ratio of bulk modulus of fluid to rigidity of rock, 0.03-0.07. The fluid-filled crack is excited intermittently by an impulsive pressure drop that varies in magnitude within the range of 0.4 to 40 bar. Such disturbance appears to be consistent with a triggering mechanism associated with choked flow conditions in the crack. C1 UNIV ALASKA,INST GEOPHYS,US GEOL SURVEY,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775. RP CHOUET, BA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. NR 68 TC 156 Z9 156 U1 7 U2 18 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 1994 VL 62 IS 1-4 BP 95 EP 135 DI 10.1016/0377-0273(94)90030-2 PG 41 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800007 ER PT J AU LAHR, JC CHOUET, BA STEPHENS, CD POWER, JA PAGE, RA AF LAHR, JC CHOUET, BA STEPHENS, CD POWER, JA PAGE, RA TI EARTHQUAKE CLASSIFICATION, LOCATION, AND ERROR ANALYSIS IN A VOLCANIC ENVIRONMENT - IMPLICATIONS FOR THE MAGMATIC SYSTEM OF THE 1989-1990 ERUPTIONS AT REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID TREMOR AB Determination of the precise locations of seismic events associated with the 1989-1990 eruptions of Redoubt Volcano posed a number of problems, including poorly known crustal velocities, a sparse station distribution, and an abundance of events with emergent phase onsets. In addition, the high relief of the volcano could not be incorporated into the HYPOELLIPSE earthquake location algorithm. This algorithm was modified to allow hypocenters to be located above the elevation of the seismic stations. The velocity model was calibrated on the basis of a posteruptive seismic survey, in which four chemical explosions were recorded by eight stations of the permanent network supplemented with 20 temporary seismographs deployed on and around the volcanic edifice. The model consists of a stack of homogeneous horizontal layers; setting the top of the model at the summit allows events to be located anywhere within the volcanic edifice. Detailed analysis of hypocentral errors shows that the long-period (LP) events constituting the vigorous 23-hour swarm that preceded the initial eruption on December 14 could have originated from a point 1.4 km below the crater floor. A similar analysis of LP events in the swarm preceding the major eruption on January 2 shows they also could have originated from a point, the location of which is shifted 0.8 km northwest and 0.7 km deeper than the source of the initial swarm. We suggest this shift in LP activity reflects a northward jump in the pathway for magmatic gases caused by the sealing of the initial pathway by magma extrusion during the last half of December. Volcano-tectonic (VT) earthquakes did not occur until after the initial 23-hour-long swarm. They began slowly just below the LP source and their rate of occurrence increased after the eruption of 01:52 AST on December 15, when they shifted to depths of 6 to 10 km. After January 2 the VT activity migrated gradually northward; this migration suggests northward propagating withdrawal of magma from a plexus of dikes and/or sills located in the 6 to 10 km depth range. Precise relocations of selected events prior to January 2 clearly resolve a narrow, steeply dipping, pencil-shaped concentration of activity in the depth range of 1-7 km, which illuminates the conduit along which magma was transported to the surface. A third event type, named hybrid, which blends the characteristics of both VT and LP events, originates just below the LP source, and may reflect brittle failure along a zone intersecting a fluid-filled crack. The distribution of hybrid events is elongated 0.2-0.4 km in an east-west direction. This distribution may offer constraints on the orientation and size of the fluid-filled crack inferred to be the source of the LP events. C1 UNIV ALASKA,INST GEOPHYS,US GEOL SURVEY,FAIRBANKS,AK 99775. RP LAHR, JC (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. RI Jiao, Liqing/A-8821-2011 NR 15 TC 177 Z9 181 U1 1 U2 17 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 1994 VL 62 IS 1-4 BP 137 EP 151 DI 10.1016/0377-0273(94)90031-0 PG 15 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800008 ER PT J AU STEPHENS, CD CHOUET, BA PAGE, RA LAHR, JC POWER, JA AF STEPHENS, CD CHOUET, BA PAGE, RA LAHR, JC POWER, JA TI SEISMOLOGICAL ASPECTS OF THE 1989-1990 ERUPTIONS AT REDOUBT VOLCANO, ALASKA - THE SSAM PERSPECTIVE SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article AB SSAM is a simple and inexpensive tool for continuous monitoring of average seismic amplitudes within selected frequency bands in near real-time on a PC-based data acquisition system. During the 1989-1990 eruption sequence at Redoubt Volcano, the potential of SSAM to aid in rapid identification of precursory Long-Period (LP) event swarms was realized, and since this time SSAM has been incorporated in routine monitoring efforts of the Alaska Volcano Observatory. In particular, an eruption that occurred on April 6 was successfully forecast primarily on the basis of recognizing the precursory LP activity on SSAM. Of twenty-two significant eruptions that occurred between December 14 and April 21, eleven had precursory swarms longer than one hour in duration that could be detected on SSAM. For individual swarms, the patterns of relative spectral amplitudes are distinct at each station and remain largely stationary through time, thus indicating that one source may have been preferentially and repeatedly activated throughout the swarm. Typically, a single spectral band dominates the signal at each seismic station: for the vigorous one-day swarm that preceded the first eruption on December 14, signals were sharply peaked in the 1.9-2.7 Hz band at the closest station, located 4 km from the vent, but were dominated by 1.3-1.9 Hz energy at three more distant stations located 7.5-22 km from the vent. The tendency for the signals from different swarms recorded at the same station to be peaked in the same frequency band suggests that all of the sources are characterized by a predominant length scale. Signals from the precursory LP swarms became weaker as the eruption sequence progressed, and swarms that occurred in March and April could only be detected at seismographs on the volcanic edifice. Onset times of precursory LP swarms prior to eruptions ranged from a few hours to about one week, but after the initial vent-clearing phase that ended December 19 these intervals tended to become progressively shorter for successive swarms. These trends in the relative onset times and intensities of successive precursory LP swarms are consistent with an overall depressurization of the magmatic system through time. In general, each of the swarms had an emergent onset, but the intensities did not always increase steadily until the eruptions. Instead, as the time of an eruption approached the intensity usually increased more rapidly before peaking and then declining prior to the eruption; for three of the swarms, two distinct peaks in intensity were apparent. The time intervals between final peaks in swarm intensity and ensuing eruptions ranged from about 2 hours to almost 2 days, but the peaks always occurred closer to the eruptions than to the swarm onsets. Both the onset of LP swarm activity and a decline in intensity prior to an eruption may represent critical points in the process of pressurization that drives the now of fluids and gas in a sealed magmatic system. A notable exception to this pattern is the eruption of March 9 which lacked a detectable precursory LP swarm, but was followed by an unusually long period of strong LP seismicity that may have been stimulated by a depressurization of the magmatic system resulting from dome failure. On both December 14 and January 2, the spectra of early syn-eruptive signals have peaked signatures much like those of the spectra of precursory LP activity from shortly before the eruptions; these similarities may indicate that the source of precursory seismicity continued to be active during at least the early part of each eruption. In syn-eruptive signals from March and April recorded at stations on the volcanic edifice, the dominant spectral energy progressively shifts with time during the eruption to lower frequencies; at least part of the energy in these signals may have been generated by the debris flows associated with dome failures. C1 UNIV ALASKA,INST GEOPHYS,US GEOL SURVEY,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775. RP STEPHENS, CD (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. NR 17 TC 38 Z9 38 U1 0 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 AUG PY 1994 VL 62 IS 1-4 BP 153 EP 182 DI 10.1016/0377-0273(94)90032-9 PG 30 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800009 ER PT J AU PAGE, RA LAHR, JC CHOUET, BA POWER, JA STEPHENS, CD AF PAGE, RA LAHR, JC CHOUET, BA POWER, JA STEPHENS, CD TI STATISTICAL FORECASTING OF REPETITIOUS DOME FAILURES DURING THE WANING ERUPTION OF REDOUBT VOLCANO, ALASKA, FEBRUARY-APRIL 1990 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article AB The waning phase of the 1989-1990 eruption of Redoubt Volcano in the Cook Inlet region of south-central Alaska comprised a quasi-regular pattern of repetitious dome growth and destruction that lasted from February 15 to late April 1990. The dome failures produced ash plumes hazardous to airline traffic. In response to this hazard, the Alaska Volcano Observatory sought to forecast these ash-producing events using two approaches. One approach built on early successes in issuing warnings before major eruptions on December 14, 1989 and January 2, 1990. These warnings were based largely on changes in seismic activity related to the occurrence of precursory swarms of long-period seismic events. The search for precursory swarms of long-period seismicity was continued through the waning phase of the eruption and led to warnings before tephra eruptions on March 23 and April 6. The observed regularity of dome failures after February 15 suggested that a statistical forecasting method based on a constant-rate failure model might also be successful. The first statistical forecast was issued on March 16 after seven events had occurred, at an average interval of 4.5 days. At this time, the interval between dome failures abruptly lengthened. Accordingly, the forecast was unsuccessful and further forecasting was suspended until the regularity of subsequent failures could be confirmed. Statistical forecasting resumed on April 12, after four dome failure episodes separated by an average of 7.8 days. One dome failure (April 15) was successfully forecast using a 70% confidence window, and a second event (April 21) was narrowly missed before the end of the activity. The cessation of dome failures after April 21 resulted in a concluding false alarm. Although forecasting success during the eruption was limited, retrospective analysis shows that early and consistent application of the statistical method using a constant-rate failure model and a 90% confidence window could have yielded five successful forecasts and two false alarms; no events would have been missed. On closer examination, the intervals between successive dome failures are not uniform but tend to increase with time. This increase attests to the continuous, slowly decreasing supply of magma to the surface vent during the waning phase of the eruption. The domes formed in a precarious position in a breach in the summit crater rim where they were susceptible to gravitational collapse. The instability of the February 15-April 21 domes relative to the earlier domes is attributed to reaming the lip of the vent by a laterally directed explosion during the major dome-destroying eruption of February 15, a process which would leave a less secure foundation for subsequent domes. C1 UNIV ALASKA,INST GEOPHYS,US GEOL SURVEY,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775. RP PAGE, RA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 977,MENLO PK,CA 94025, USA. NR 12 TC 13 Z9 13 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 AUG PY 1994 VL 62 IS 1-4 BP 183 EP 196 DI 10.1016/0377-0273(94)90033-7 PG 14 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800010 ER PT J AU MILLER, TP AF MILLER, TP TI DOME GROWTH AND DESTRUCTION DURING THE 1989-1990 ERUPTION OF REDOUBT VOLCANO SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID LAVA AB Much of the six-month-long 1989-1990 eruption of Redoubt Volcano consisted of a dome-growth and -destructive phase in which 14 short-lived viscous silicic andesite domes were emplaced and 13 subsequently destroyed. The life span of an individual dome ranged from 3 to 21 days and volumes are estimated at 1 X 10(6) to 30 X 10(6) m(3) Magma supply rates to the vent area averaged about 5 X 10(5) m(3)/day for most of the dome-building phase and ranged from a high of 2.2 X 10(6) m(3) per day initially to a low of 1.8 X 10(5) m(3) per day at the waning stages of the eruption. The total volume of all domes is estimated to be about 90 X 10(6) m(3) and may represent as much as 60-70% of the volume fdr the entire eruption. The site of 1989-1990 dome emplacement, like that in 1966, was on the margin of a north-facing amphitheatre-like summit crater. The domes were confined on the east and west by steep cliffs of pre-eruption cone-building volcanic rocks and thus were constrained to grow vertically. Rapid upward growth in a precarious site caused each dome to spread preferentially to the north, resulting in eventual gravitational collapse. As long as the present conduit remains active at Redoubt Volcano, any dome formed in a new eruption will be confined to a narrow steeply-sloping gorge, leading to rapid vertical growth and a tendency to collapse gravitationally. Repetitive cycles of dome formation and failure similar to those seen in 1989-1990 are probably the norm and must be considered in future hazard analyses of Redoubt Volcano. RP MILLER, TP (reprint author), US GEOL SURVEY,ALASKA VOLCANO OBSERV,4200 UNIV DR,ANCHORAGE,AK 99508, USA. NR 22 TC 49 Z9 49 U1 1 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 AUG PY 1994 VL 62 IS 1-4 BP 197 EP 212 DI 10.1016/0377-0273(94)90034-5 PG 16 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800011 ER PT J AU GARDNER, CA NEAL, CA WAITT, RB JANDA, RJ AF GARDNER, CA NEAL, CA WAITT, RB JANDA, RJ TI PROXIMAL PYROCLASTIC DEPOSITS FROM THE 1989-1990 ERUPTION OF REDOUBT VOLCANO, ALASKA - STRATIGRAPHY, DISTRIBUTION, AND PHYSICAL CHARACTERISTICS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article AB More than 20 eruptive events during the 1989-1990 eruption of Redoubt Volcano emplaced a complex sequence of lithic pyroclastic-flow, -surge, -fall, ice-diamict, and lahar deposits mainly on the north side of the volcano. The deposits record the changing eruption dynamics from initial gas-rich vent-clearing explosions to episodic gas-poor lava-dome extrusions and failures. The repeated dome failures produced lithic pyroclastic flows that mixed with snow and glacial ice to generate lahars that were channelled off Drift glacier into the Drift River valley. Some of the dome failures occurred without precursory seismic warning and appeared to result solely from gravitational instability. Material from the disrupted lava domes avalanched down a steep, partly ice-filled canyon incised on the north flank of the volcano and came to rest on the heavily crevassed surface of the piedmont lobe of Drift glacier. Most dome-collapse events resulted in single, monolithologic, massive to reversely graded, medium- to coarse-grained, sandy pyroclastic-flow deposits containing abundant dense dome clasts. These deposits vary in thickness, grain size, and texture depending on distance from the vent and local topography; deposits are finer and better sorted down flow, thinner and finer on hummocks, and thicker and coarser where ponded in channels cut through the glacial ice. The initial vent-clearing explosions emplaced unusual deposits of glacial ice, snow, and rock in a frozen matrix on the north and south flanks of the volcano. Similar deposits were described at Nevado del Ruiz, Columbia and have probably been emplaced at other snow-and-ice-clad volcanoes, but poor preservation makes them difficult to recognize in the geologic record. In a like fashion, most deposits from the 1989-1990 eruption of Redoubt Volcano may be difficult to recognize and interpret in the future because they were emplaced in an environment where glacio-fluvial processes dominate and quickly obscure the primary depositional record. C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. RP GARDNER, CA (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661, USA. NR 45 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 AUG PY 1994 VL 62 IS 1-4 BP 213 EP 250 DI 10.1016/0377-0273(94)90035-3 PG 38 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800012 ER PT J AU SCOTT, WE MCGIMSEY, RG AF SCOTT, WE MCGIMSEY, RG TI CHARACTER, MASS, DISTRIBUTION, AND ORIGIN OF TEPHRA-FALL DEPOSITS OF THE 1989-1990 ERUPTION OF REDOUBT VOLCANO, SOUTH-CENTRAL ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT ST-HELENS; PYROCLASTIC FLOWS; SURGES AB The 1989-1990 eruption of Redoubt Volcano spawned about 20 areally significant tephra-fall deposits between December 14, 1989 and April 26, 1990. Tephra plumes rose to altitudes of 7 to more than 10 km and were carried mainly northward and eastward by prevailing winds, where they substantially impacted air travel, commerce, and other activities. In comparison to notable eruptions of the recent past, the Redoubt events produced a modest amount of tephra-fall deposits - 6 X 10(7) to 5 X 10(10) kg for individual events and a total volume (dense-rock equivalent) of about 3-5 X 10(7) m(3) of andesite and dacite. Two contrasting tephra types were generated by these events. Pumiceous tephra-fall deposits of December 14 and 15 were followed on December 16 and all later events by fine-grained lithic-crystal tephra deposits, much of which fell as particle aggregates. The change in the character of the tephra-fall deposits reflects their fundamentally different modes of origin. The pumiceous deposits were produced by magmatically driven explosions. The fine-grained lithic-crystal deposits were generated by two processes. Hydrovolcanic vent explosions generated tephra-fall deposits of December 16 and 19. Such explosions continued as a tephra source, but apparently with diminishing importance, during events of January and February. Ash clouds of lithic pyroclastic flows generated by collapse of actively growing lava domes probably contributed to tephra-fall deposits of all events from January 2 to April 26, and were the sole source of tephra fall for at least the last 4 deposits. C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. RP SCOTT, WE (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 52 TC 44 Z9 44 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 AUG PY 1994 VL 62 IS 1-4 BP 251 EP 272 DI 10.1016/0377-0273(94)90036-1 PG 22 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800013 ER PT J AU CASADEVALL, TJ AF CASADEVALL, TJ TI THE 1989-1990 ERUPTION OF REDOUBT VOLCANO, ALASKA - IMPACTS ON AIRCRAFT OPERATIONS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID PARTICLE; ASH AB The December 1989-June 1990 eruption of Redoubt Volcano affected commercial and military air operations in the vicinity of Anchorage, Alaska. These effects were due to the direct impact of volcanic ash on jet aircraft, as well as to the rerouting and cancellations of flight operations owing to eruptive activity. Between December and February, five commercial jetliners were damaged from ash encounters. The most serious incident took place on December 15, 1989 when a Boeing 747-400 aircraft temporarily lost power of all four engines after encountering an ash cloud as the airplane descended for a landing in Anchorage. While there were no injuries to passengers, the damage to engines, avionics, and aircraft structure from this encounter is estimated at $80 million. Four additional encounters between jet aircraft and Redoubt ash clouds occurred in the Anchorage area on December 15 and 16, 1989 and February 21, 1990; none resulted in engine failure. Two additional encounters took place on December 17, 1989 when jet airliners encountered the Redoubt cloud over west Texas. At the time of these encounters, the cloud was up to 55 hours old and had traveled in excess of 2,900 nautical miles (5,300 km). Following the December 15 encounters, Anchorage International Airport remained open, however, most airline companies canceled operations for up to several days. As communications between Federal agencies and airlines improved, and as a better understanding of the nature and behavior of ash-rich eruption clouds was achieved, most airlines resumed normal service by early January 1990. The resulting loss of revenue at Anchorage International Airport during several months following the eruption is estimated to total $2.6 million. The impact on general aviation and military operations consisted mostly of cancellation and rerouting of flights. RP CASADEVALL, TJ (reprint author), US GEOL SURVEY,DENVER FED CTR,DEPT INTERIOR,BOX 25046,MAILSTOP 903,DENVER,CO 80225, USA. NR 39 TC 144 Z9 145 U1 4 U2 19 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 1994 VL 62 IS 1-4 BP 301 EP 316 DI 10.1016/0377-0273(94)90038-8 PG 16 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800015 ER PT J AU GERLACH, TM WESTRICH, HR CASADEVALL, TJ FINNEGAN, DL AF GERLACH, TM WESTRICH, HR CASADEVALL, TJ FINNEGAN, DL TI VAPOR SATURATION AND ACCUMULATION IN MAGMAS OF THE 1989-1990 ERUPTION OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID CARBON-DIOXIDE; SULFUR; INCLUSIONS; SOLUBILITY; MELT; EMISSIONS; CHLORINE; WATER; ATMOSPHERE; GLASSES AB The 1989-1990 eruption of Redoubt Volcano, Alaska, provided an opportunity to compare petrologic estimates of SO2 and Cl emissions with estimates of SO2 emissions based on remote sensing data and estimates of Cl emissions based on plume sampling. In this study, we measure the sulfur and chlorine contents of melt inclusions and matrix glasses in the eruption products to determine petrologic estimates of SO2 and Cl emissions. We compare the results with emission estimates based on COSPEC and TOMS data for SO2 and data for Cl/SO2 in plume samples. For the explosive vent clearing period (December 14-22, 1989), the petrologic estimate for SO2 emission is 21,000 tons, or similar to 12% of a TOMS estimate of 175,000 tons. For the dome growth period (December 22, 1989 to mid-June 1990), the petrologic estimate for SO2 emission is 18,000 tons, or similar to 3% of COSPEC-based estimates of 572,000-680,000 tons. The petrologic estimates give a total SO2 emission of only 39,000 tons compared to an integrated TOMS/COSPEC emission estimate of similar to 1,000,000 tons for the whole eruption, including quiescent degassing after mid-June 1990. Petrologic estimates also appear to underestimate Cl emissions, but apparent HCl scavenging in the plume complicates Cl emission comparisons. Several potential sources of 'excess sulfur' often invoked to explain petrologic SO2 deficits are concluded to be unlikely for the 1989-1990 Redoubt eruption - e.g., breakdown of sulfides, breakdown of anhydrite, release of SO2 from a hydrothermal system, degassing of commingled infusions of basalt in the magma chamber, and syn-eruptive degassing of sulfur from melt present in non-erupted magma. Leakage and/or diffusion of sulfur from melt inclusions do not provide convincing explanations for the petrologic SO2 deficits either. The main cause of low petrologic estimates for SO2 is that melt inclusions do not represent the total sulfur content of the Redoubt magmas, which were vapor-saturated magmas carrying most of their sulfur in an accumulated vapor phase. Almost all the sulfur of the SO2 emissions was present prior to emission as accumulated magmatic vapor at 6-10 km depth in the magma that supplied the eruption; whole-rock normalized concentrations of gaseous excess S in these magmas remained at similar to 0.2 wt.% throughout the eruption, equivalent to similar to 0.7 vol.% at depth. Data for CO2 emissions during the eruption indicate that CO2 at whole-rock concentrations of similar to 0.6 wt.% in the erupted magma was a key factor in creating the vapor saturation and accumulation condition making a vapor phase source of excess sulfur possible at depth. When explosive volcanism involves magma with accumulated vapor, melt inclusions do not provide a sufficient basis for predicting SO2 emissions. Thus, petrologic estimates made for SO2 emissions during explosive eruptions of the past may be too low and may significantly underestimate impacts on climate and the chemistry of the atmosphere. C1 SANDIA NATL LABS,DEPT GEOCHEM 6118,ALBUQUERQUE,NM 87185. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP GERLACH, TM (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,500 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 48 TC 87 Z9 89 U1 2 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 AUG PY 1994 VL 62 IS 1-4 BP 317 EP 337 DI 10.1016/0377-0273(94)90039-6 PG 21 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800016 ER PT J AU TRABANT, DC WAITT, RB MAJOR, JJ AF TRABANT, DC WAITT, RB MAJOR, JJ TI DISRUPTION OF DRIFT GLACIER AND ORIGIN OF FLOODS DURING THE 1989-1990 ERUPTIONS OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article AB Melting of snow and glacier ice during the 1989-1990 eruption of Redoubt Volcano caused winter flooding of the Drift River. Drift glacier was beheaded when 113 to 121 X 10(6) m(3) of perennial snow and ice were mechanically entrained in hot-rock avalanches and pyroclastic flows initiated by the four largest eruptions between 14 December 1989 and 14 March 1990. The disruption of Drift glacier was dominated by mechanical disaggregation and entrainment of snow and glacier ice. Hot-rock avalanches, debris flows, and pyroclastic flows incised deep canyons in the glacier ice thereby maintaining a large ice-surface area available for scour by subsequent flows. Downvalley flow theologies were transformed by the melting of snow and ice entrained along the upper and middle reaches of the glacier and by seasonal snowpack incorporated from the surface of the lower glacier and from the river valley. The seasonal snowpack in the Drift River valley contributed to lahars and floods a cumulative volume equivalent to about 35 X 10(6) m(3) of water, which amounts to nearly 30% of the cumulative flow volume 22 km downstream from the volcano. The absence of high-water marks in depressions and of ice-collapse features in the glacier indicated that no large quantities of meltwater that could potentially generate lahars were stored on or under the glacier; the water that generated the lahars that swept Drift River valley was produced from the proximal, eruption-induced volcaniclastic flows by melting of snow and ice. C1 US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661. RP TRABANT, DC (reprint author), US GEOL SURVEY,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99775, USA. OI Major, Jon/0000-0003-2449-4466 NR 10 TC 23 Z9 23 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 AUG PY 1994 VL 62 IS 1-4 BP 369 EP 385 DI 10.1016/0377-0273(94)90043-4 PG 17 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800020 ER PT J AU DORAVA, JM MEYER, DF AF DORAVA, JM MEYER, DF TI HYDROLOGIC HAZARDS IN THE LOWER DRIFT RIVER BASIN ASSOCIATED WITH THE 1989-1990 ERUPTIONS OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID HELENS AB The eruptions of Redoubt Volcano between December 14, 1989 and April 26, 1990 triggered flows of snow, ice, water, sediment, and debris that traveled down the Drift River as far as its mouth, about 40 km downstream. A major explosive eruption and dome collapse on January 2, 1990 produced the largest flow. The peak discharge of this flow at a location 22 km downstream from the volcano was estimated to be between 12,000 and 60,000 m(3) per second. The estimated peak discharge of this event is more than 100 times larger than the 100-year meteorologically generated flood estimated for the Drift River. Pyroclastic flows and hot meltwater scoured the surface of Drift Glacier on the north flank of the volcano and were transformed into multipulsed, multiphased debris flows. Several other significant flows were generated by eruptions during this period: the two largest of these occurred on December 15, 1989 and February 15, 1990. Subsequent channel changes threatened the Drift River Oil Terminal built on an alluvial fan near the mouth of the Drift River. RP DORAVA, JM (reprint author), US GEOL SURVEY,ANCHORAGE,AK 99508, USA. NR 37 TC 10 Z9 10 U1 1 U2 1 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 1994 VL 62 IS 1-4 BP 387 EP 407 DI 10.1016/0377-0273(94)90044-2 PG 21 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800021 ER PT J AU WAITT, RB GARDNER, CA PIERSON, TC MAJOR, JJ NEAL, CA AF WAITT, RB GARDNER, CA PIERSON, TC MAJOR, JJ NEAL, CA TI UNUSUAL ICE DIAMICTS EMPLACED DURING THE DECEMBER 15, 1989 ERUPTION OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT ST-HELENS; WASHINGTON; AVALANCHE; LAHARS; FLOODS AB Ice diamict comprising clasts of glacier ice and subordinate rock debris in a matrix of ice (snow) grains, coarse ash, and frozen pore water was deposited during the eruption of Redoubt Volcano on December 15, 1989. Rounded clasts of glacier ice and snowpack are as large as 2.5 m, clasts of Redoubt andesite and basement crystalline rocks reach 1 m, and tabular clasts of entrained snowpack are as long as 10 m. Ice diamict was deposited on both the north and south volcano flanks. On Redoubt's north flank along the east side of Drift piedmont glacier and outwash valley, ice diamict accumulated as at least 3 units, each 1-5 m thick. Two ice-diamict layers underlie a pumice-lithic fall tephra that accumulated on December 15 from 10:15 to 11:45 AST. A third ice diamict overlies the pumiceous tephra. Some of the ice diamicts have a basal 'ice-sandstone' layer. The north side icy flows reached as far as 14 km laterally over an altitude drop of 2.3 km and covered an area of about 5.7 km(2). On Crescent Glacier on the south volcano flank, a composite ice diamict is locally as thick as 20 m. It travelled 4.3 km over an altitude drop of 1.7 km, covering about 1 km(2). The much higher mobility of the northside flows was influenced by their much higher water contents than the southside flow(s). Erupting hot juvenile andesite triggered and turbulently mixed with snow avalanches at snow-covered glacier heads. These flows rapidly entrained more snow, firn, and ice blocks from the crevassed glacier. On the north flank, a trailing watery phase of each ice-diamict flow swept over and terraced the new icy deposits. The last (and perhaps each) flood reworked valley-floor snowpack and swept 35 km downvalley to the sea. Ice diamict did not form during eruptions after December 15 despite intervening snowfalls. These later pyroclastic flows swept mainly over glacier ice rather than snowpack and generated Iaharic floods rather than snowflows. Similar flows of mixed ice grains and pyroclastic debris resulted from the November 13, 1985 eruption of Nevado del Ruiz volcano and from eruptions of snowclad Mount St, Helens in 1982-1984. Such deposits at snowclad volcanoes are initially broad and geomorphically distinct, but they soon become extensively reworked and hard to recognize in the geologic record. C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. RP WAITT, RB (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. OI Major, Jon/0000-0003-2449-4466 NR 24 TC 22 Z9 22 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 AUG PY 1994 VL 62 IS 1-4 BP 409 EP 428 DI 10.1016/0377-0273(94)90045-0 PG 20 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800022 ER PT J AU NYE, CJ SWANSON, SE AVERY, VF MILLER, TP AF NYE, CJ SWANSON, SE AVERY, VF MILLER, TP TI GEOCHEMISTRY OF THE 1989-1990 ERUPTION OF REDOUBT VOLCANO .1. WHOLE-ROCK MAJOR- AND TRACE-ELEMENT CHEMISTRY SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID ALEUTIAN ARC; BASALTS; SATURATION; MAGMATISM AB The 1989-1990 eruption of Redoubt Volcano produced medium-K calc-alkaline andesite and dacite of limited compositional range (58.2-63.4% SiO2) and entrained quenched andesitic inclusions (55% SiO2) which bear chemical similarities to the rest of the ejecta. The earliest (December 15) magmas are pumiceous, often compositionally banded, and the majority is relatively mafic (<59% SiO2). The most silicic magmas of the eruption are the late December to early January domes (up to 63.4% SiO2). Subsequent magmas formed domes and rare pumices which converge on 60% SiO2. Chemical variations among ejecta comprise tight, linear, two-component arrays for all elements for which the analytical uncertainty is much less than the compositional range. The two-component arrays are interpreted as mixing arrays between unrelated magmas because several of the arrays are at steep angles to the normal liquid line of descent. Additionally, the felsic endmember cannot be easily related to the mafic endmember by normal high-temperature igneous processes (e.g., the silicic endmember has higher Zr yet lower Hf than the mafic endmember). Also relative enrichments of highly incompatible elements are dramatically different across the arrays. The mixing event must have preceded eruption by a significant, yet unspecified amount of time because groundmass glass compositions are homogeneous for all post-December samples (Swanson et al., 1994-this volume), in spite of the whole-rock chemical diversity. This implies time for additional crystallization after the mixing event. Swanson et al. (1994-this volume) discuss evidence for a potentially different mixing event recorded only in December 15 magmas. Cognate cumulate xenoliths composed of pl + cpx + opx + hb + mt + melt were recovered from January and April deposits. These blocks differ from local batholithic country rock in their low concentrations of incompatible elements (e.g., Rb < 5 ppm vs 20-90 ppm, Ba < 150 ppm vs 300-2000 ppm) and low SiO2 (<50 wt.% vs >60 wt.%). They have Mg, Cr, Ni, Sc, and V contents higher than the andesites, but lower than Redoubt basalts and basaltic andesites. Thus, they may be crystallization products of andesites, but do not represent the cumulate residue of basalt fractionation. The xenoliths were probably derived from a shallow or intermediate crustal chamber. C1 ALASKA DIV GEOL & GEOPHYS SURVEYS,FAIRBANKS,AK 99709. UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775. UNIV ALASKA,DEPT GEOL & GEOPHYS,FAIRBANKS,AK 99775. US GEOL SURVEY,ANCHORAGE,AK 99508. RP NYE, CJ (reprint author), ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99709, USA. NR 31 TC 38 Z9 38 U1 1 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 AUG PY 1994 VL 62 IS 1-4 BP 429 EP 452 DI 10.1016/0377-0273(94)90046-9 PG 24 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800023 ER PT J AU SWANSON, SE NYE, CJ MILLER, TP AVERY, VF AF SWANSON, SE NYE, CJ MILLER, TP AVERY, VF TI GEOCHEMISTRY OF THE 1989-1990 ERUPTION OF REDOUBT VOLCANO .2. EVIDENCE FROM MINERAL AND GLASS CHEMISTRY SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID EASTERN ALEUTIAN ARC; PETROLOGY; MAGMAS AB Early stages (December 1989) of the 1989-1990 eruption of Redoubt Volcano produced two distinct lavas. Both lavas are high-silica andesites with a narrow range of bulk composition (58-64 wt.%) and similar mineralogies (phenocrysts of plagioclase, hornblende, augite, hypersthene and Fe-Ti oxides in a groundmass of the same phases plus glass). The two lavas are distinguished by groundmass glass compositions, one is dacitic and the other rhyolitic. Sharp boundaries between the two glasses in compositionally banded pumices, lack of extensive coronas on hornblende phenocrysts, and seismic data suggest that a magma-mixing event immediately preceeded the eruption in December 1989. Textural disequilibrium in the phenocrysts suggests both magmas (dacitic and rhyolitic glasses) had a mixing history prior to their interaction and eruption in 1989. Sievey plagioclase and overgrowths of magnetite on ilmenite are textures that are at least consistent with magma mixing. The presence of two hornblende compositions (one a high-Al pargasitic hornblende and one a low-Al magnesiohornblende) in both the dacitic and rhyolitic groundmasses indicates a mixing event to yield these two amphibole populations prior to the magma mixing in December 1989. The pargasitic hornblende and the presence of Ca-rich overgrowths in the sievey zones of the plagioclase together indicate at least one component of this earlier mixing event was a mafic magma, either a basalt or a basaltic andesite. Eruptions in 1990 produced only andesite with a rhyolitic groundmass glass. Glass compositions in the 1990 andesite are identical to the rhyolitic glass in the 1989 andesite. Cognate xenoliths from the magma chamber (or conduit) are also found in the 1990 lavas. Magma mixing probably triggered the eruption in 1989. The eruption ended when this rather viscous (rhyolitic groundmass glass, magma capable of entraining sidewall xenoliths) magma stabalized within the conduit. C1 UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775. ALASKA DIV GEOL & GEOPHYS SURVEYS,FAIRBANKS,AK 99709. US GEOL SURVEY,ANCHORAGE,AK 99508. RP SWANSON, SE (reprint author), UNIV ALASKA,DEPT GEOL & GEOPHYS,FAIRBANKS,AK 99775, USA. NR 27 TC 32 Z9 32 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 AUG PY 1994 VL 62 IS 1-4 BP 453 EP 468 DI 10.1016/0377-0273(94)90047-7 PG 16 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800024 ER PT J AU CORNELIUS, RR VOIGHT, B AF CORNELIUS, RR VOIGHT, B TI SEISMOLOGICAL ASPECTS OF THE 1989-1990 ERUPTION AT REDOUBT VOLCANO, ALASKA - THE MATERIALS FAILURE FORECAST METHOD (FFM) WITH RSAM AND SSAM SEISMIC DATA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID TREMOR AB Seismic activity during the December 1989 to April 1990 eruption of Redoubt Volcano, Alaska, has been tracked by the Alaska Volcano Observatory using Real-time Seismic Amplitude Measurement (RSAM) and Seismic Spectral Amplitude Measurement (SSAM) systems with up to five stations. Data consist of 10-minute averages of the absolute amplitudes of seismometer output. These data have been used to test in hindsight the Materials Failure Forecast Method (FFM), which attempts to define the time of eruption with a time series for precursory phenomena whose rate of change accelerates measurably before events. Practical application of the method emphasizes inverse-rate plots, both for early detection of signal emergent from background, and for event forecasting. Eruption windows are determined by graphical or numerical extrapolation of the inverse-rate trend and by intersection of a data envelope, reflecting data scatter and consistency, with an empirical critical rate near the time of eruption. Prior to the dome-destroying eruption of January 2, rate changes were of sufficient consistency, duration, and intensity for a qualitative or quantitative FFM predictive analysis, using either RSAM or SSAM. Signal-to-noise ratio was high for both RSAM or SSAM data sets, and FFM analyses could have provided useful support for decision making. Following January 2, in association with a rapid succession of dome-collapse eruptions, signal strength diminished and RSAM signal-to-noise ratio declined. The most distinct patterns on RSAM reflected noise rather than signal, and forecasting exclusively based for RSAM would have been misleading. By eliminating the noise in excluded frequencies, an enhanced signal-to-noise ratio was generally produced by SSAM for banded frequencies near 2 Hz. After January 2, only SSAM exhibited signal-to-noise ratios suitable for FFM analysis. Inverse-SSAM plots could have been informative for early detection of precursory long-period seismicity. The prospect of combining the FFM approach with spectral amplitudes in selected frequencies offers considerable promise. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP CORNELIUS, RR (reprint author), PENN STATE UNIV,DEPT GEOSCI,UNIVERSITY PK,PA 16802, USA. NR 29 TC 29 Z9 29 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 AUG PY 1994 VL 62 IS 1-4 BP 469 EP 498 DI 10.1016/0377-0273(94)90048-5 PG 30 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800025 ER PT J AU HOBLITT, RP AF HOBLITT, RP TI AN EXPERIMENT TO DETECT AND LOCATE LIGHTNING ASSOCIATED WITH ERUPTIONS OF REDOUBT VOLCANO SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID FRACTURE; EMISSION AB A commercially-available lightning-detection system was temporarily deployed near Cook Inlet, Alaska in an attempt to remotely monitor volcanogenic lightning associated with eruptions of Redoubt Volcano. The system became operational on February 14, 1990; lightning was detected in 11 and located in 9 of the 13 subsequent eruptions. The lightning was generated by ash clouds rising from pyroclastic density currents produced by collapse of a lava dome emplaced near Redoubt's summit. Lightning discharge (flash) location was controlled by topography, which channeled the density currents, and by wind direction. In individual eruptions, early flashes tended to have a negative polarity (negative charge is lowered to ground) while late flashes tended to have a positive polarity (positive charge is lowered to ground), perhaps because the charge-separation process caused coarse, rapid-settling particles to be negatively charged and fine, slow-settling particles to be positively charged. Results indicate that lightning detection and location is a useful adjunct to seismic volcano monitoring, particularly when poor weather or darkness prevents visual observation. The simultaneity of seismicity and lightning near a volcano provides the virtual certainty that an ash cloud is present. This information is crucial for aircraft safety and to warn threatened communities of impending tephra falls. The Alaska Volcano Observatory has now deployed a permanent lightning-detection network around Cook Inlet. RP HOBLITT, RP (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 18 TC 30 Z9 30 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 AUG PY 1994 VL 62 IS 1-4 BP 499 EP 517 DI 10.1016/0377-0273(94)90049-3 PG 19 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800026 ER PT J AU CASADEVALL, TJ DOUKAS, MP NEAL, CA MCGIMSEY, RG GARDNER, CA AF CASADEVALL, TJ DOUKAS, MP NEAL, CA MCGIMSEY, RG GARDNER, CA TI EMISSION RATES OF SULFUR-DIOXIDE AND CARBON-DIOXIDE FROM REDOUBT VOLCANO, ALASKA DURING THE 1989-1990 ERUPTIONS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID AUGUSTINE VOLCANO; GAS EMISSIONS AB Airborne measurements of sulfur dioxide emission rates in the gas plume emitted from fumaroles in the summit crater of Redoubt Volcano were started on March 20, 1990 using the COSPEC method. During the latter half of the period of intermittent dome growth and destruction, between March 20 and mid-June 1990, sulfur dioxide emission rates ranged from approximately 1250 to 5850 t/d, rates notably higher than for other convergent-plate boundary volcanoes during periods of active dome growth. Emission rates following the end of dome growth from late June 1990 through May 1991 decreased steadily to less than 75 t/d. The largest mass of sulfur dioxide was released during the period of explosive vent clearing when explosive degassing on December 14-15 injected at least 175,000 +/- 50,000 tonnes of SO2 into the atmosphere. Following the explosive eruptions of December 1989, Redoubt Volcano entered a period of intermittent dome growth from late December 1989 to mid-June 1990 during which Redoubt emitted a total mass of SO, ranging from 572,000 +/- 90,000 tonnes to 680,000 +/- 90,000 tonnes. From mid-June 1990 through May 1991, the volcano was in a state of posteruption degassing into the troposphere, producing approximately 183,000 +/- 50,000 tonnes of SO2. We estimate that Redoubt Volcano released a minimum mass of sulfur dioxide of approximately 930,000 tonnes. While COSPEC data were not obtained frequently enough to enable their use in eruption prediction, SO2 emission rates clearly indicated a consistent decline in emission rates between March through October 1990 and a continued low level of emission rates through the first half of 1991. Values from consecutive daily measurements of sulfur dioxide emission rates spanning the March 23, 1990 eruption decreased in the three days prior to eruption. That decrease was coincident with a several-fold increase in the frequency of shallow seismic events, suggesting partial sealing of the magma conduit to gas loss that resulted in pressurization of the shallow magma system and an increase in earthquake activity. Unlike the short-term SO2 decrease in March 1990, the long-term decrease of sulfur dioxide emission rates from March 1990 through May 1991 was coincident with low rates of seismic energy release and was interpreted to reflect gradual depressurization of the shallow magma reservoir. The long-term declines in seismic energy release and in SO2 emission rates led AVO scientists to conclude on April 19, 1991 that the potential for further eruptive activity from Redoubt Volcano had diminished, and on this basis, the level of concern color code for the volcano was changed from code yellow (Volcano is restless; earthquake activity is elevated; activity may include extrusion oflava) to code green (Volcano is in its normal 'dormant' state). C1 US GEOL SURVEY,ALASKA VOLCANO OBSERV,ANCHORAGE,AK 99508. US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661. RP CASADEVALL, TJ (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 903,DENVER,CO 80225, USA. NR 25 TC 38 Z9 39 U1 0 U2 5 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 1994 VL 62 IS 1-4 BP 519 EP 530 DI 10.1016/0377-0273(94)90050-7 PG 12 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800027 ER PT J AU MILLER, TP CHOUET, BA AF MILLER, TP CHOUET, BA TI THE 1989-1990 ERUPTIONS OF REDOUBT VOLCANO, ALASKA - PREFACE SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Editorial Material C1 US GEOL SURVEY,MENLO PK,CA 94025. RP MILLER, TP (reprint author), US GEOL SURVEY,ALASKA VOLCANO OBSERV,4200 UNIV DR,ANCHORAGE,AK 99508, USA. NR 0 TC 2 Z9 2 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 AUG PY 1994 VL 62 IS 1-4 BP R7 EP R7 DI 10.1016/0377-0273(94)90024-8 PG 1 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800001 ER PT J AU FAUROT, MW WHITE, RG AF FAUROT, MW WHITE, RG TI FEEDING ECOLOGY OF LARVAL FISHES IN LAKE ROOSEVELT, WASHINGTON SO NORTHWEST SCIENCE LA English DT Article AB Food habits, feeding selectivity, and diet overlap were analyzed for larval walleye (Stizostedion vitreum), yellow perch (Perca flavescens), sculpins (Cottus spp.), and suckers (Catostomus spp.) collected in Lake Roosevelt, Washington, in May to July 1982. Larval diet of fishes in this unique co-occurring species mix has not been previously described. Larval fishes 4-25 mm long were sampled weekly with 0.5-m townets from nearshore sites at two stations. Zooplankton was collected with Miller samplers to characterize food availability. The most abundant food items were calanoid copepods in walleye stomachs, calanoid and cyclopoid copepods in yellow perch stomachs, and cyclopoid copepods in sclupin stomachs. Larval walleyes 9 to 24 mm long also preyed upon larval fishes. Cladocerans were important food only to larval suckers, which fed almost exclusively on Bosmina and Chydorus. Feeding selectivity, determined by Wilcoxon's nonparametric signed-rank analysis, showed positive selection for several prey items among the fish taxa. Schoener's niche overlap values indicated significant diet overlap between walleye and yellow perch. During our study period, effects of competition on growth, survival, and character divergence of larval walleye and yellow perch was minor. Annual variation in reservoir conditions could results in stronger or weaker competitive interactions than we observed since zooplankton composition is known to influence fry feeding success and growth. C1 MONTANA STATE UNIV, DEPT BIOL, US FISH & WILDLIFE SERV, MONTANA COOPERAT FISHERY RES UNIT, BOZEMAN, MT 59717 USA. NR 0 TC 3 Z9 5 U1 1 U2 4 PU NORTHWEST SCIENTIFIC ASSOC PI SEATTLE PA JEFFREY DUDA, USGS, WESTERN FISHERIES RES CTR, 6505 NE 65 ST, SEATTLE, WA 98115 USA SN 0029-344X EI 2161-9859 J9 NORTHWEST SCI JI Northwest Sci. PD AUG PY 1994 VL 68 IS 3 BP 189 EP 196 PG 8 WC Ecology SC Environmental Sciences & Ecology GA PJ430 UT WOS:A1994PJ43000005 ER PT J AU HOSTETTLER, FD KVENVOLDEN, KA AF HOSTETTLER, FD KVENVOLDEN, KA TI GEOCHEMICAL CHANGES IN CRUDE-OIL SPILLED FROM THE EXXON-VALDEZ SUPERTANKER INTO PRINCE-WILLIAM-SOUND, ALASKA SO ORGANIC GEOCHEMISTRY LA English DT Article DE N-ALKANES; ISOPRENOIDS; POLYCYCLIC ALIPHATIC AND AROMATIC HYDROCARBONS; BIOMARKERS; TERPANES; STERANES; CORRELATION; ALTERATION; OIL SPILL; PRINCE-WILLIAM SOUND; ALASKA ID AROMATIC-HYDROCARBONS; FATE; DEGRADATION; PERSISTENCE; MATURATION; STERANES AB North Slope crude oil spilled from the T/V Exxon Valdez in March 1989 and contaminated about 500 km of Prince William Sound shoreline. Aliphatic and aromatic hydrocarbons in oil samples collected in August 1990 and June 1992 from beaches on six islands impacted by the spill have been compared with the hydrocarbons from North Slope crude oil taken from the stricken tanker. Degradation processes have changed the physical appearance of this residual spilled oil; the beached oil as collected ranged from a light brown color, to a heavy black viscous oil, to a black, powder-like residue. In these physically different samples, terpane, sterane, and aromatic sterane distributions, as well as carbon isotope values, are similar and correlate with the original Exxon Valdez oil. On the other hand, n-alkanes, isoprenoids, and many of the polycyclic aromatic hydrocarbons which are present in the original crude oil are dramatically altered in the oil samples collected from the beaches. RP HOSTETTLER, FD (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 999,MENLO PK,CA 94025, USA. NR 39 TC 67 Z9 69 U1 5 U2 13 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 AUG-SEP PY 1994 VL 21 IS 8-9 BP 927 EP 936 DI 10.1016/0146-6380(94)90051-5 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NX461 UT WOS:A1994NX46100011 ER PT J AU BRALOWER, TJ ARTHUR, MA LECKIE, RM SLITER, WV ALLARD, DJ SCHLANGER, SO AF BRALOWER, TJ ARTHUR, MA LECKIE, RM SLITER, WV ALLARD, DJ SCHLANGER, SO TI TIMING AND PALEOCEANOGRAPHY OF OCEANIC DYSOXIA ANOXIA IN THE LATE BARREMIAN TO EARLY APTIAN (EARLY CRETACEOUS) SO PALAIOS LA English DT Review ID SEA DRILLING PROJECT; ATMOSPHERIC CARBON-DIOXIDE; MARINE ORGANIC-CARBON; CALCAREOUS NANNOFOSSILS; FALKLAND PLATEAU; ATLANTIC-OCEAN; PLANKTONIC FORAMINIFERS; MAGNETIC STRATIGRAPHY; SOUTH-ATLANTIC; NORTH-ATLANTIC AB Normal marine deposition in the early Aptian was interrupted by an episode of ocean-wide dysoxia/anoxia. This event is recorded by the occurrence of organic carbon-rich sediments in land sections from Europe and Deep Sea-Drilling Project (DSDP)/Ocean Drilling Program (ODP) sites in the North and South Atlantic, Indian and Pacific Ocean Basins. To elucidate the origin, and spatial and temporal relationships of these carbonaceous sediments, we have conducted an integrated biostratigraphic, lithostratigraphic and geochemical investigation of fourteen sections from a range of geographic and oceanographic settings. Based on the resulting high-resolution, integrated foraminiferal and nannofossil biostratigraphy, it appears that most locations were characterized by a relatively brief interval of peak dysoxia/anoxia (less than a million years in duration), in the midst of a longer (approximately 2-3 million year) interval of intermittent oxygen deficiency which began in the late Barremian. This peak can be recognized either from organic carbon contents or from intervals barren of calcareous plankton; in most places it lies within the lower Aptian Globigerinelloides blowi foraminiferal Zone and the Chiastozygus litterarius nannofossil Zone (Conusphaera rothii Subzone) and occurred shortly after magnetic Chron CMO. The dysoxic/anoxic interval affected sites in a wide range of oceanic paleoenvironments: Nannofossil assemblage data indicate highly variable fertility during this interval and suggest that no single model can account for the origin of all organic carbon-rich horizons. These data indicate that peak oxygen deficiency corresponded to a highly eutrophic interval but less intense dysoxic/anoxic periods were characterized by oligotrophic conditions. The late Barremian to early Aptian was a time of evolutionary radiation in both planktonic foraminifers and calcareous nannofossils, no significant changes in speciation rates are associated with the oxygen-deficient interval itself. The extinction of one of the dominant Early Cretaceous nannoplankton species, Nannoconus steinmannii may be related to events which led to dysoxia/anoxia including periodically higher fertility. Tectonovolcanic events such as increased production of mid-plate oceanic crust may have indirectly induced the dysoxic/anoxic episode by causing complex changes in climate, ocean chemistry and circulation, and sea level. The lack of a clear stratigraphic correlation between C(org)-rich horizons and the carbon isotopic record indicates that these inter-relationships are extremely complex. C1 PENN STATE UNIV,DEPT GEOSCI,STATE COLL,PA 16802. UNIV MASSACHUSETTS,DEPT GEOL,AMHERST,MA 01003. USGS,DIV PALEONTOL & STRATIG,MENLO PK,CA 94025. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60201. RP BRALOWER, TJ (reprint author), UNIV N CAROLINA,DEPT GEOL,CHAPEL HILL,NC 27599, USA. RI Arthur, Michael/E-2872-2014; OI Arthur, Michael/0000-0002-3028-6279; Leckie, R. Mark/0000-0002-7311-2180 NR 198 TC 190 Z9 203 U1 0 U2 14 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 0883-1351 J9 PALAIOS JI Palaios PD AUG PY 1994 VL 9 IS 4 BP 335 EP 369 DI 10.2307/3515055 PG 35 WC Geology; Paleontology SC Geology; Paleontology GA PD521 UT WOS:A1994PD52100003 ER PT J AU ROELOFFS, E LANGBEIN, J AF ROELOFFS, E LANGBEIN, J TI THE EARTHQUAKE PREDICTION EXPERIMENT AT PARKFIELD, CALIFORNIA SO REVIEWS OF GEOPHYSICS LA English DT Review ID SAN-ANDREAS FAULT; LOMA-PRIETA EARTHQUAKE; MAGNETIC-FIELD MEASUREMENTS; GREAT 1857 EARTHQUAKE; MODERATE EARTHQUAKES; CRUSTAL DEFORMATION; SEISMIC QUIESCENCE; VELOCITY STRUCTURE; ROCK FRICTION; GEODETIC DATA AB Since 1985, a focused earthquake prediction experiment has been in progress along the San Andreas fault near the town of Parkfield in central California. Parkfield has experienced six moderate earthquakes since 1857 at average intervals of 22 years, the most recent a magnitude 6 event in 1966. The probability of another moderate earthquake soon appears high, but studies assigning it a 95% chance of occurring before 1993 now appear to have been over-simplified. The identification of a Parkfield fault ''segment'' was initially based on geometric features in the surface trace of the San Andreas fault, but more recent microearthquake studies have demonstrated that those features do not extend to seismogenic depths. On the other hand, geodetic measurements are consistent with the existence of a ''locked'' patch on the fault beneath Parkfield that has presently accumulated a slip deficit equal to the slip in the 1966 earthquake. A magnitude 4.7 earthquake in October 1992 brought the Parkfield experiment to its highest level of alert, with a 72-hour public warning that there was a 37% chance of a magnitude 6 event. However, this warning proved to be a false alarm. Most data collected at Parkfield indicate that strain is accumulating at a constant rate on this part of the San Andreas fault, but some interesting departures from this behavior have been recorded. Here we outline the scientific arguments bearing on when the next Parkfield earthquake is likely to occur and summarize geophysical observations to date. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP US GEOL SURVEY, CASCADES VOLCANO OBSERV, 5400 MACARTHUR BLVD, VANCOUVER, WA 98661 USA. NR 120 TC 74 Z9 75 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 EI 1944-9208 J9 REV GEOPHYS JI Rev. Geophys. PD AUG PY 1994 VL 32 IS 3 BP 315 EP 336 DI 10.1029/94RG01114 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PH870 UT WOS:A1994PH87000004 ER PT J AU SAVAGE, MK LI, L EATON, JP JONES, CH BRUNE, JN AF SAVAGE, MK LI, L EATON, JP JONES, CH BRUNE, JN TI EARTHQUAKE REFRACTION PROFILES OF THE ROOT OF THE SIERRA-NEVADA SO TECTONICS LA English DT Article ID WESTERN UNITED-STATES; CRUSTAL STRUCTURE; MANTLE DEFORMATION; CENTRAL CALIFORNIA; BATHOLITH; UPLIFT; VALLEY; LITHOSPHERE; EVOLUTION; TECTONICS AB We examine the seismic structure of the Sierra Nevada using records of nine earthquakes and one explosion in and near the Sierra, recorded on stations in the Sierra. We first interpret travel times from these paths, which are confined to a single tectonic block, in terms of one-dimensional structures. The most nearly reversed pair of earthquakes, the 1966 Truckee and 1983 Durrwood Meadows earthquakes, share refracted (P(n)) arrival times (corrected to surface focus) along a line t = 8.75 +/- 0.25 + DELTA/8.0, suggesting that a nearly flat layer of 8.0 km/s mantle material lies at depths of 46-48 km. First arrivals from these events do not constrain velocities from almost-equal-to 30 to 45 km depth. Secondary arrivals and some first arrivals from other earthquakes suggest that velocities in part of this region range between 6.9 and 7.8 km/s. The presence of this ''7.x-km/s'' layer can help to explain previous contradictory observations. The 7.x-km/s layer could be interpreted as either the mafic bottom of a silicic, Mesozoic magmatic arc or as accreted mafic underplating or rejuvenated mantle related to Cenozoic arc volcanism or Basin and Range spreading. Arrivals at stations in the foothills and the crest of the Sierra cannot be fit with a single longitudinal structure, indicating a lateral variation of velocity structure. These variations support previously inferred variations of lithospheric structure, with higher-velocity, thinner crust to the west beneath the Sierran foothills and slower-velocity crust (or possibly upper mantle) beneath the high mountains in the eastern Sierra. Rapid changes in arrival times between stations separated by short distances in the eastern Sierra suggest that a sharp boundary exists between the Sierra and the Basin and Range at Moho depths. We also present fresh evidence of the asymmetry of the root of the Sierra, wherein arrivals from earthquakes on the west of the Sierra are delayed within the Sierra and return to original values in the Basin and Range, while arrivals from earthquakes and explosions from the Sierra into the Great Valley. We suggest that if the 7.x-km/s material occurs in a wedge above the Moho, then the asymmetry can be explained by arrivals from the west being delayed by the dipping 8.0-km/s Moho, while those from the east may be entering the root along a 7.x-km/s layer that is near the depth of the Basin and Range Moho. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP SAVAGE, MK (reprint author), UNIV NEVADA,MACKAY SCH MINES,SEISMOL LAB,RENO,NV 89557, USA. RI Savage, Martha/F-1857-2011; OI Savage, Martha/0000-0002-2080-0676; Jones, Craig/0000-0002-1698-0408 NR 50 TC 17 Z9 17 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD AUG PY 1994 VL 13 IS 4 BP 803 EP 817 DI 10.1029/93TC03488 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB140 UT WOS:A1994PB14000005 ER PT J AU MUKASA, SB FLOWER, MFJ MIKLIUS, A AF MUKASA, SB FLOWER, MFJ MIKLIUS, A TI THE ND-ISOTOPIC, SR-ISOTOPIC AND PB-ISOTOPIC CHARACTER OF LAVAS FROM TAAL, LAGUNA-DE-BAY AND ARAYAT VOLCANOS, SOUTHWESTERN LUZON, PHILIPPINES - IMPLICATIONS FOR ARC MAGMA PETROGENESIS SO TECTONOPHYSICS LA English DT Article ID TRACE-ELEMENT CONSTRAINTS; EAST PACIFIC RISE; ISLAND-ARC; UPPER MANTLE; SEDIMENT SUBDUCTION; CRUSTAL STRUCTURE; LESSER ANTILLES; OCEAN RIDGES; BASALTS; LEAD AB Following the amalgamation of a collage of pre-Neogene terranes largely by strike-slip and convergence mechanisms to form the Philippine islands, volcanic chains, related to oppositely dipping subduction zones, developed along the eastern and western margins of the archipelago. There is ample field evidence that this volcanic activity, predominantly calc-alkaline in chemical character, had commenced by the Oligocene. Volcanoes resulting from subduction along the Manila-Negros trench in the west (e.g., Taal, Laguna de Bay and Arayat) form a high-angle linear array, trending away from the MORB field on Pb-isotopic covariation diagrams; have the highest Sr- and lowest Nd-isotopic compositions, of the two chains (but nevertheless plotting above bulk earth on the Sr-87/Sr-86 versus Nd-143/Nd-144 Nd covariation diagram); and exhibit Sm/Nd and Rb/Sr values that are lower and higher, respectively, than the estimated values for bulk earth. While the Sm/Nd and Rb/Sr characteristics are common to both chains, volcanoes associated with the Philippine-East Luzon trench have Pb-isotopic compositions that fall in the Indian Ocean MORB field and that require time-integrated evolution in a high Th/U environment. They also have higher Nd- and lower Sr-isotopic ratios. The source materials of Philippine volcanoes, therefore, have undergone varied recent enrichments in LILE, as indicated by the decoupling of isotopic and elemental ratios. These enrichments, particularly for the western volcanoes, cannot be entirely due to small degrees of partial melting in the mantle wedge, considering that they were accompanied by elevations in radiogenic Pb. Elevated Pb ratios are best explained by the introduction of subducted, continentally derived sediments. The sedimentary component in the western volcanoes is probably the South China Sea sediments derived largely from Eurasia. That this component is not available in the Philippine-East Luzon trench is reflected by the fact that the eastern volcanoes have higher Nd- and lower Sr-isotopic ratios as well as less radiogenic common Pb. C1 US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HI 96718. UNIV ILLINOIS,DEPT GEOL SCI,CHICAGO,IL 60680. RP MUKASA, SB (reprint author), UNIV MICHIGAN,DEPT GEOL SCI,1006 CC LITTLE BLDG,ANN ARBOR,MI 48109, USA. NR 65 TC 25 Z9 26 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD JUL 30 PY 1994 VL 235 IS 1-2 BP 205 EP 221 DI 10.1016/0040-1951(94)90024-8 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PD712 UT WOS:A1994PD71200013 ER PT J AU PRICE, LC AF PRICE, LC TI PETROLEUM GEOCHEMISTRY - METAMORPHIC FREE-FOR-ALL SO NATURE LA English DT Editorial Material RP PRICE, LC (reprint author), US GEOL SURVEY,DENVER FED CTR,PETR GEOL BRANCH,MS-940,DENVER,CO 80225, USA. NR 15 TC 20 Z9 23 U1 1 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUL 28 PY 1994 VL 370 IS 6487 BP 253 EP 254 DI 10.1038/370253a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NZ229 UT WOS:A1994NZ22900033 ER PT J AU CALVIN, WM KING, TVV CLARK, RN AF CALVIN, WM KING, TVV CLARK, RN TI HYDROUS CARBONATES ON MARS - EVIDENCE FROM MARINER 6/7 INFRARED SPECTROMETER AND GROUND-BASED TELESCOPIC SPECTRA SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID REFLECTANCE SPECTROSCOPY; WEATHERING PRODUCTS; PHYSICAL-PROPERTIES; DUST; MINERALS; SURFACE; REGION; SALTS; CRYSTALLINE; METEORITES AB Absorption features at 2.28 and 5.4 mum identified in Mariner 6/7 infrared spectrometer and terrestrial telescopic spectra are consistent with the spectra of hydrous magnesium carbonates such as hydromagnesite and artinite. Spectral characteristics of these hydrous carbonates are different from those of the anhydrous carbonates, as the former do not have the strong spectral features typically associated with anhydrous carbonates such as calcite and siderite. Theoretical mixing indicates that, depending on the type of hydrous carbonate, 10-20 wt % can be incorporated into the regolith without contradicting the spectral observations or the Viking x ray fluorescence chemical analysis. Hydrous carbonates form as weathering products of mafic minerals in the presence of H2O and CO2, even in the Antarctic. Their formation as evaporite minerals from either original magmas or hydrothermally altered rocks is consistent with the Martian environment, provided liquid water is or has been at least transiently present. On Earth, formation of hydrous Mg carbonates is associated with the production of amorphous iron oxides, which is consistent with both the environment and the inferred surface mineralogy of Mars. These minerals are about 60 wt % H2O, CO3, and OH; if they axe abundant everywhere at the 10% level, then about 6% of the surface weight could be volatiles bound in this type of mineral. Although the stability of hydrous carbonates in a Martian environment is uncertain, there may be kinetic factors inhibiting the dehydration of these minerals, which may persist meta.stably in the current environment. Although the spectroscopic evidence for anhydrous carbonates is scant, the possible presence of hydrous carbonates provides an appealing mechanism for the existence of carbonates on Mars. C1 US GEOL SURVEY,GEOPHYS BRANCH,DENVER,CO 80225. RP CALVIN, WM (reprint author), US GEOL SURVEY,ASTROGEOL BRANCH,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 81 TC 59 Z9 59 U1 2 U2 12 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 JUL 25 PY 1994 VL 99 IS E7 BP 14659 EP 14675 DI 10.1029/94JE01090 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NY861 UT WOS:A1994NY86100003 ER PT J AU WALLACE, PJ GERLACH, TM AF WALLACE, PJ GERLACH, TM TI MAGMATIC VAPOR SOURCE FOR SULFUR-DIOXIDE RELEASED DURING VOLCANIC-ERUPTIONS - EVIDENCE FROM MOUNT-PINATUBO SO SCIENCE LA English DT Article ID ANHYDRITE-BEARING PUMICES; EL-CHICHON VOLCANO; STRATOSPHERIC SO2; 1982 ERUPTIONS; WATER; GLASSES; JUNE AB Sulfur dioxide (SO2) released by the explosive eruption of Mount Pinatubo on 15 June 1991 had an impact on climate and stratospheric ozone. The total mass of SO2 released was much greater than the amount dissolved in the magma before the eruption, and thus an additional source for the excess SO2 is required. Infrared spectroscopic analyses of dissolved water and carbon dioxide in glass inclusions from quartz phenocrysts demonstrate that before eruption the magma contained a separate, SO2-bearing vapor phase. Data for gas emissions from other volcanoes in subduction-related arcs suggest that preeruptive magmatic vapor is a major source of the SO2 that is released during many volcanic eruptions. C1 US GEOL SURVEY, CASCADES VOLCANO OVSERV, VANCOUVER, WA 98661 USA. RP WALLACE, PJ (reprint author), UNIV CHICAGO, DEPT GEOPHYS SCI, 5734 S ELLIS AVE, CHICAGO, IL 60637 USA. NR 31 TC 126 Z9 129 U1 6 U2 20 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 JUL 22 PY 1994 VL 265 IS 5171 BP 497 EP 499 DI 10.1126/science.265.5171.497 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NY216 UT WOS:A1994NY21600021 PM 17781307 ER PT J AU HAINES, JW SALLENGER, AH AF HAINES, JW SALLENGER, AH TI VERTICAL STRUCTURE OF MEAN CROSS-SHORE CURRENTS ACROSS A BARRED SURF ZONE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID UNDERTOW; VELOCITIES; BEACH; FLOW AB Mean cross-shore currents observed across a barred surf zone are compared to model predictions. The model is based on a simplified momentum balance with a turbulent boundary layer at the bed. Turbulent exchange is parameterized by an eddy viscosity formulation, with the eddy viscosity A(upsilon) independent of time and the vertical coordinate. Mean currents result from gradients due to wave breaking and shoaling, and the presence of a mean setup of the free surface. Descriptions of the wave field are provided by the wave transformation model of Thornton and Guza [1983]. The wave transformation model adequately reproduces the observed wave heights across the surf zone. The mean current model successfully reproduces the observed cross-shore flows. Both observations and predictions show predominantly offshore flow with onshore flow restricted to a relatively thin surface layer. Successful application of the mean flow model requires an eddy viscosity which varies horizontally across the surf zone. Attempts are made to parameterize this variation with some success. The data does not discriminate between alternative parameterizations proposed. The overall variability in eddy viscosity suggested by the model fitting should be resolvable by field measurements of the turbulent stresses. Consistent shortcomings of the parameterizations, and the overall modeling effort, suggest avenues for further development and data collection. RP HAINES, JW (reprint author), US GEOL SURVEY,CTR COASTAL GEOL,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 24 TC 37 Z9 37 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-OCEANS JI J. Geophys. Res.-Oceans PD JUL 15 PY 1994 VL 99 IS C7 BP 14223 EP 14242 DI 10.1029/94JC00427 PG 20 WC Oceanography SC Oceanography GA NY037 UT WOS:A1994NY03700013 ER PT J AU LI, YG VIDALE, JE AKI, K MARONE, CJ LEE, WHK AF LI, YG VIDALE, JE AKI, K MARONE, CJ LEE, WHK TI FINE-STRUCTURE OF THE LANDERS FAULT ZONE - SEGMENTATION AND THE RUPTURE PROCESS SO SCIENCE LA English DT Article ID 1984 MORGAN-HILL; ANDREANOF ISLANDS EARTHQUAKE; FRACTURE SEISMIC ANISOTROPY; AFTERSHOCK SEQUENCE; VELOCITY STRUCTURE; GROUND MOTION; CALIFORNIA; INVERSION; ACCELERATION; DYNAMICS AB Observations and modeling of 3- to 6-hertz seismic shear waves trapped within the fault zone of the 1992 Landers earthquake series allow the fine structure and continuity of the zone to be evaluated. The fault, to a depth of at least 12 kilometers, is marked by a zone 100 to 200 meters wide where shear velocity is reduced by 30 to 50 percent. This zone forms a seismic waveguide that extends along the southern 30 kilometers of the Landers rupture surface and ends at the fault bend about 18 kilometers north of the main shock epicenter. Another fault plane waveguide, disconnected from the first, exists along the northern rupture surface. These observations, in conjunction with surface slip, detailed seismicity patterns, and the progression of rupture along the fault, suggest that several simple rupture planes were involved in the Landers earthquake and that the inferred rupture front hesitated or slowed at the location where the rupture jumped from one to the next plane. Reduction in rupture velocity can tentatively be attributed to fault plane complexity, and variations in moment release can be attributed to variations in available energy. C1 US GEOL SURVEY,MENLO PK,CA 94025. MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. RP LI, YG (reprint author), UNIV SO CALIF,DEPT EARTH SCI,LOS ANGELES,CA 90089, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 39 TC 63 Z9 67 U1 4 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUL 15 PY 1994 VL 265 IS 5170 BP 367 EP 370 DI 10.1126/science.265.5170.367 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NW816 UT WOS:A1994NW81600032 PM 17838038 ER PT J AU LOVLEY, DR WOODWARD, JC CHAPELLE, FH AF LOVLEY, DR WOODWARD, JC CHAPELLE, FH TI STIMULATED ANOXIC BIODEGRADATION OF AROMATIC-HYDROCARBONS USING FE(III) LIGANDS SO NATURE LA English DT Article ID DENITRIFYING CONDITIONS; AQUIFER MICROORGANISMS; DISSIMILATORY FE(III); MICROBIAL-DEGRADATION; ORGANIC CONTAMINANTS; REDUCING CONDITIONS; HYDROGEN-PEROXIDE; IRON REDUCTION; SHALLOW SAND; GROUNDWATER AB CONTAMINATION of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow(1-7). Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive(1,5-8). Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access(9). Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in tbe presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing the bioavailability of Fe(III) by adding suitable ligands provides a potential alternative to oxygen addition for the bioremediation of petroleum-contaminated aquifers. C1 US GEOL SURVEY, DIV WATER RESOURCES, COLUMBIA, SC 29210 USA. RP US GEOL SURVEY, DIV WATER RESOURCES, 430 NATL CTR, RESTON, VA 22092 USA. NR 28 TC 220 Z9 232 U1 8 U2 47 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JUL 14 PY 1994 VL 370 IS 6485 BP 128 EP 131 DI 10.1038/370128a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NW804 UT WOS:A1994NW80400052 PM 8022480 ER PT J AU HUGHES, S HALL, J LUETGERT, JH AF HUGHES, S HALL, J LUETGERT, JH TI THE SEISMIC VELOCITY STRUCTURE OF THE NEWFOUNDLAND APPALACHIAN OROGEN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CRUSTAL STRUCTURE; CANADIAN APPALACHIANS; WESTERN NEWFOUNDLAND; CONTINENTAL-CRUST; DELAMINATION; TERRANES; ZONE AB The deep structure of the Newfoundland Appalachian orogen is investigated by analyses of three intersecting seismic refraction/wide-angle reflection profiles which traverse the Gander and Dunnage zones or central mobile belt of Newfoundland. A simultaneous travel time inversion for velocity and interface was applied to the in-line seismic refraction/wide-angle reflection data and constrained by synthetic amplitude models. The results of the modeling procedure show a subhorizontally layered crust with upper crustal velocities ranging from 5.4 to 6.2 km/s, a midcrustal velocity of 6.25-6.35 km/s, and a lower crustal velocity of 6.7 +/- 0.2 km/s. The top of the lower crust is marked by a series of prominent reflections between 18 and 23 km depth which suggest a complex layered velocity interface. Strong laterally coherent Moho reflections indicate a sharp crust-mantle transition at 35 +/- 3 km. The uppermost mantle has a velocity of 8.0 +/- 0.2 km/s, and a reflecting horizon at 55 km depth suggests an increase to velocities approaching 8.5 km/s. Normal moveout corrections applied to fan profiles provide constraining evidence for the reflecting horizon at the top of the lower crust and laterally continuous Moho reflections at 11-12 s two-way travel time. Comparisons with a coincident deep seismic reflection profile show that the refraction and reflection Mohos match to better than 2-3 km. Bulk Poisson's ratios of 0.23-0.24 for the whole crust calculated from P(m)P/S(m)S travel times suggest a crust dominated by quartzofeldspathic lithologies and a notable absence of voluminous mafic additions to the lower crust. The absence of a deep crustal root, coupled with the bulk intermediate composition inferred for the lower crust from the seismic refraction/wide-angle data, implies that the crust beneath central Newfoundland has undergone multiple periods of reactivation and equilibration following successive orogenic episodes. C1 MEM UNIV NEWFOUNDLAND, DEPT EARTH SCI, ST JOHNS A1B 3X5, NEWFOUNDLAND, CANADA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RI Hall, Jeremy/E-4467-2013 NR 37 TC 21 Z9 21 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 1994 VL 99 IS B7 BP 13633 EP 13653 DI 10.1029/94JB00653 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NW515 UT WOS:A1994NW51500008 ER PT J AU SAVAGE, JC LISOWSKI, M SVARC, JL AF SAVAGE, JC LISOWSKI, M SVARC, JL TI POSTSEISMIC DEFORMATION FOLLOWING THE 1989 (M = 7.1) LOMA-PRIETA, CALIFORNIA, EARTHQUAKE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GLOBAL POSITIONING SYSTEM; CRUSTAL DEFORMATION; MODEL; FAULT; ZONES AB Postseismic deformation along a 90-km profile bisecting the projected surface trace of the coseismic rupture of the 1989 Loma Prieta earthquake has been monitored by frequent GPS surveys for 3.3 years following the earthquake. In addition to the expected deformation associated with secular strain accumulation on the San Andreas and Calaveras faults, deformation associated with postseismic readjustment has been detected. Most of that deformation can be attributed to 1.5 m right-lateral and 0.9 m reverse postseismic slip on a 5-km-wide downdip extension of the Loma Prieta rupture. In addition, there seems to be a 0.1 m postseismic collapse of the Loma Prieta rupture zone in the direction perpendicular to the plane of the rupture. The fault-normal (N48-degrees-E) surface displacements plotted as a function of time exhibit a curvature suggesting a relaxation time of about 1.4 years. Similar plots of the fault-parallel (N42-degrees-W) displacement components do not exhibit significant curvature. Presumably, the deformation shown in those plots is dominated by secular strain accumulation along the San Andreas and Calaveras faults rather than postseismic relaxation. RP SAVAGE, JC (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MAILSTOP 977, MENLO PK, CA 94025 USA. NR 14 TC 37 Z9 39 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 JUL 10 PY 1994 VL 99 IS B7 BP 13757 EP 13765 DI 10.1029/94JB00507 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NW515 UT WOS:A1994NW51500015 ER PT J AU NECKLES, HA NEILL, C AF NECKLES, HA NEILL, C TI HYDROLOGIC CONTROL OF LITTER DECOMPOSITION IN SEASONALLY FLOODED PRAIRIE MARSHES SO HYDROBIOLOGIA LA English DT Article DE DECOMPOSITION; MARSH; LITTER; NITROGEN; SCOLOCHLOA-FESTUCACEA ID ZOSTERA-MARINA L; SALT-MARSH; TYPHA-LATIFOLIA; ORGANIC-MATTER; NITROGEN; SWAMP; REDUCTION; ABUNDANCE; DYNAMICS; FOREST AB The effect of seasonal inundation on the decomposition of emergent macrophyte litter (Scolochloa festucacea) was examined under experimental flooding regimes in a northern prairie marsh. Stem and leaf litter was subjected to six aboveground inundation treatments (ranging from never flooded to flooded April through October) and two belowground treatments (nonflooded and flooded April to August). Flooding increased the rate of mass loss from litter aboveground but retarded decay belowground. Aboveground, N concentration decreased and subsequently increased earlier in the longer flooded treatments, indicating that flooding decreased the time that litter remained in the leaching and immobilization phases of decay. Belowground, both flooded and nonflooded litter showed an initial rapid loss of N, but concentration and percent of original N remaining were greater in the nonflooded marsh throughout the first year. This suggested that more N was immobilized on litter under the nonflooded, more oxidizing soil conditions. Both N concentration and percent N remaining of belowground litter were greater in the flooded than the nonflooded marsh the second year, suggesting that N immobilization was enhanced after water-level drawdown. These results suggest different mechanisms by which flooding affects decomposition in different wetland environments. On the soil surface where oxygen is readily available, flooding accelerates decomposition by increasing moisture. Belowground, flooding creates anoxic conditions that slow decay. The typical hydrologic pattern in seasonally flooded prairie marshes of spring flooding followed by water-level drawdown in summer may maximize system decomposition rates by allowing rapid decomposition aboveground in standing water and by annually alleviating soil anoxia. C1 MARINE BIOL LAB,CTR ECOSYST,WOODS HOLE,MA 02543. RP NECKLES, HA (reprint author), US FISH & WILDLIFE SERV,NATL WETLANDS RES CTR,700 CAJUNDOME BLVD,LAFAYETTE,LA 70506, USA. NR 32 TC 44 Z9 49 U1 6 U2 16 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD JUL 8 PY 1994 VL 286 IS 3 BP 155 EP 165 DI 10.1007/BF00006247 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA PC829 UT WOS:A1994PC82900004 ER PT J AU VIDALE, JE AF VIDALE, JE TI GEOPHYSICS - A SNAPSHOT OF WHOLE MANTLE FLOW SO NATURE LA English DT Editorial Material ID NORTHWEST PACIFIC; ISLAND ARCS; CONVECTION; MODEL RP VIDALE, JE (reprint author), US GEOL SURVEY,OFF EARTHQUAKES & VOLCANOES,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 12 TC 2 Z9 2 U1 0 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUL 7 PY 1994 VL 370 IS 6484 BP 16 EP 17 DI 10.1038/370016a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NV711 UT WOS:A1994NV71100028 ER PT J AU ROEDDER, E AF ROEDDER, E TI RADIOACTIVE-WASTE DISPOSAL - NEED TO WEIGH VALID EVIDENCE SO ACADEMIC MEDICINE LA English DT Letter C1 US GEOL SURVEY,WASHINGTON,DC 20242. RP ROEDDER, E (reprint author), HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 SN 1040-2446 J9 ACAD MED JI Acad. Med. PD JUL PY 1994 VL 69 IS 7 BP 565 EP 565 DI 10.1097/00001888-199407000-00011 PG 1 WC Education, Scientific Disciplines; Health Care Sciences & Services SC Education & Educational Research; Health Care Sciences & Services GA NX178 UT WOS:A1994NX17800017 PM 8018266 ER PT J AU EVANS, HT BRUSEWITZ, AM AF EVANS, HT BRUSEWITZ, AM TI CRYSTAL-STRUCTURE OF POTASSIUM PENTAVANADATE SO ACTA CHEMICA SCANDINAVICA LA English DT Article AB Potassium pentavanadate, K3V5O14, is trigonal, space group P31m, with a = 8.6901(5) and c = 5.0063(4) angstrom. The crystal structure has been refined with 359 three-dimensional intensity data to R = 0.056. The structure consists of layers of comer-linked square and trigonal pyramids, with all pyramid apices oriented in the same direction parallel to the c-axis, and interlayered with K+ ions. In the final structure model, 8% of the layers are oriented randomly in the opposite direction. RP EVANS, HT (reprint author), US GEOL SURVEY,NATL CTR 959,RESTON,VA 22092, USA. NR 16 TC 14 Z9 15 U1 2 U2 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0904-213X J9 ACTA CHEM SCAND JI Acta Chem. Scand. PD JUL PY 1994 VL 48 IS 7 BP 533 EP 536 PG 4 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary SC Biochemistry & Molecular Biology; Chemistry GA NZ955 UT WOS:A1994NZ95500001 ER PT J AU LICHT, DS FRITTS, SH AF LICHT, DS FRITTS, SH TI GRAY WOLF (CANIS-LUPUS) OCCURRENCES IN THE DAKOTAS SO AMERICAN MIDLAND NATURALIST LA English DT Article ID MINNESOTA; WOLVES; DISPERSAL AB Gray wolves (Canis lupus) were extirpated in North and South Dakota in the 1920-1930s and rarely reported from the mid-1940s to late 1970s. From 1981 to 1992, 10 wolves were killed in the Dakotas, five of them in 1991-1992. Mortality sites were 46-561 km from the nearest known wolf population, and four were within a single 1175 km2 area. Eight of the 10 animals were less-than-or-equal-to 2 years old, suggesting dispersing individuals. Mortality occurred in agrarian prairie areas with mean road densities of 0.71 km/km2 and human densities of 3.5/kM2. Habitat at mortality sites was radically different from where these wolves apparently originated, demonstrating extreme flexibility in dispersal behavior of wolves. Further increase in wolf occurrences in the Dakotas is likely, related to wolf population increases and range expansion in adjacent states and provinces, especially Minnesota. C1 US FISH & WILDLIFE SERV,HELENA,MT 59601. RP LICHT, DS (reprint author), US FISH & WILDLIFE SERV,1500 CAPITOL AVE,BISMARCK,ND 58501, USA. NR 28 TC 11 Z9 11 U1 1 U2 3 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, BOX 369, ROOM 295 GLSC, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD JUL PY 1994 VL 132 IS 1 BP 74 EP 81 PG 8 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA NZ327 UT WOS:A1994NZ32700008 ER PT J AU PEOPLES, AD LOCHMILLER, RL BOREN, JC LESLIE, DM ENGLE, DM AF PEOPLES, AD LOCHMILLER, RL BOREN, JC LESLIE, DM ENGLE, DM TI LIMITATIONS OF AMINO-ACIDS IN DIETS OF NORTHERN BOBWHITES (COLINUS-VIRGINIANUS) SO AMERICAN MIDLAND NATURALIST LA English DT Article ID HYDROLYSIS; METHIONINE; NITROGEN; QUAIL AB Northern bobwhite (Colinus virginianus) populations fluctuate widely in density, which may be due to changing nutritional conditions. High requirements for protein in the diet of bobwhites for reproduction and growth and the low quality of protein in many cereal grains led us to hypothesize that dietary limitations in certain essential amino acids may occur in wild bobwhite populations in western Oklahoma. We explored this hypothesis by examining seasonal changes in the amino acid composition of bobwhite diets and comparing observed levels in their diets to known requirements of a closely related species, Japanese quail (Coturnix coturnix japonica). Bobwhites were harvested seasonally (summer, autumn, winter 1989-1990) on three ranches from supplementally fed (<250 m from a food plot or feeder) and reference populations (>900 m from supplemental food). Bobwhites used supplemental food for >15% of their diet in only 1 of 6 seasons. Supplemental food did not appreciably influence body condition indices (body mass, organ masses, carcass composition), but did influence the diets of bobwhites, as evidenced by significant differences in concentrations of fat and essential amino acids in crop digesta. Although crude protein requirements apparently were met in all seasons, levels of greater-than-or-equal-to one essential amino acid in diets of reference and supplemented bobwhites were below recommended levels for growth or breeding in Japanese quail. The sulfur-containing amino acids, methionine + cystine, were consistently the most limiting nutrients in the diet, with seasonal means ranging from 0-53% below recommended levels for growth or breeding in Japanese quail. These observations support our hypothesis that selected essential amino acids may be seasonally limiting in diets of bobwhites. Dietary requirements of bobwhite for suspected limiting amino acids should be determined in feeding trials to identify more accurately the magnitude of these apparent deficiencies. C1 OKLAHOMA STATE UNIV,US FISH & WILDLIFE SERV,OKLAHOMA COOPERAT FISH & WILDLIFE RES UNIT,STILLWATER,OK 74078. OKLAHOMA STATE UNIV,DEPT ZOOL,STILLWATER,OK 74078. OKLAHOMA STATE UNIV,DEPT AGRON,STILLWATER,OK 74078. NR 41 TC 7 Z9 7 U1 0 U2 2 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, BOX 369, ROOM 295 GLSC, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD JUL PY 1994 VL 132 IS 1 BP 104 EP 116 DI 10.2307/2426205 PG 13 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA NZ327 UT WOS:A1994NZ32700011 ER PT J AU STEWART, DB AF STEWART, DB TI PRESENTATION OF THE DISTINGUISHED PUBLIC-SERVICE MEDAL FOR 1993 TO RIBBE,PAUL,H. SO AMERICAN MINERALOGIST LA English DT Article RP STEWART, DB (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 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 JUL-AUG PY 1994 VL 79 IS 7-8 BP 775 EP 776 PG 2 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PC429 UT WOS:A1994PC42900023 ER PT J AU DREW, LJ AF DREW, LJ TI MEMORIAL OF GRIFFITHS,JOHN,C. 1912-1992 SO AMERICAN MINERALOGIST LA English DT Item About an Individual RP DREW, LJ (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 1 TC 0 Z9 0 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 JUL-AUG PY 1994 VL 79 IS 7-8 BP 779 EP 780 PG 2 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA PC429 UT WOS:A1994PC42900025 ER PT J AU LOVLEY, DR PHILLIPS, EJP AF LOVLEY, DR PHILLIPS, EJP TI NOVEL PROCESSES FOR ANAEROBIC SULFATE PRODUCTION FROM ELEMENTAL SULFUR BY SULFATE-REDUCING BACTERIA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID THIOBACILLUS-FERROOXIDANS; GEN-NOV; DESULFUROMONAS-ACETOXIDANS; MANGANESE REDUCTION; COMPLETE OXIDATION; ORGANIC-COMPOUNDS; MARINE-SEDIMENTS; IRON REDUCTION; SULFIDE; TRANSFORMATIONS AB Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H-2 or organic electron donors oxidized S-0 to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum, Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S-0 with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S-0 + 3 MnO2 + 4H(+)-->SO42- + 3Mn(II) + 2H(2)O. None of the organisms evaluated could be grown with S-0 as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S-0 in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S-0 as follows: 4S(0) + 4H(2)O-->SO42 + 3HS(-) + 5 H+. Growth of Desulfobulbus propionicus with SO as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S-0 oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(TV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S-0. RP LOVLEY, DR (reprint author), US GEOL SURVEY, NATL CTR 430, DIV WATER RESOURCES, RESTON, VA 22092 USA. NR 41 TC 107 Z9 110 U1 0 U2 18 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 EI 1098-5336 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUL PY 1994 VL 60 IS 7 BP 2394 EP 2399 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA NV572 UT WOS:A1994NV57200029 PM 16349323 ER PT J AU STOLLENWERK, KG AF STOLLENWERK, KG TI GEOCHEMICAL INTERACTIONS BETWEEN CONSTITUENTS IN ACIDIC GROUNDWATER AND ALLUVIUM IN AN AQUIFER NEAR GLOBE, ARIZONA SO APPLIED GEOCHEMISTRY LA English DT Article AB Acidic water from a copper-mining area has contaminated an alluvial aquifer and stream near Globe, Arizona. The most contaminated groundwater has a pH of 3.3. and contains about 100 mmol/l SO4, 50 mmol/l Fe, 11 mmol/l Al and 3 mmol/l Cu. Reactions between alluvium and acidic groundwater were first evaluated in laboratory column experiments. A geochemical model was developed and used in the equilibrium speciation program, MINTEQA2, to simulate breakthrough curves for different constituents from the column. The geochemical model was then used to simulate the measured changes in concentration of aqueous constituents along a flow path in the aquifer. The pH was predominantly controlled by reaction with carbonate minerals. Where carbonates had been dissolved, adsorption of H+ by iron oxides was used to simulate pH. Acidic groundwater contained little or no dissolved oxygen, and most aqueous Fe was present as Fe(II). In the anoxic core of the plume, Fe(II) was oxidized by MnO2 to Fe(III), which then precipitated as Fe(OH)3. Attenuation of aqueous Cu, Co, Mn, Ni and Zn was a function of pH and could be quantitatively modeled with the diffuse-layer, surface complexation model in MINTEQA2. Aluminum precipitated as amorphous Al(OH)3 at pH >4.7 and as AlOHSO4 at pH <4.7. Aqueous Ca and SO4 were close to equilibrium with gypsum. After the alluvium in the column had reached equilibrium with acidic groundwater, uncontaminated groundwater was eluted through the column to evaluate the effect of reactants on groundwater remediation. The concentration of Fe, Mn, Cu, Co, Ni and Zn rapidly decreased to the detection limits within a few pore volumes. All of the gypsum that had precipitated initially redissolved, resulting in elevated Ca and SO4 concentrations for about 5 pore volumes. Aluminum and pH exhibited the most potential for continued adverse effects on groundwater quality. As H+ desorbed from Fe(OH)3, pH remained below 4.5 for more than 20 pore volumes, resulting in dissolution of AlOHSO4 and elevated aqueous Al. RP STOLLENWERK, KG (reprint author), US GEOL SURVEY,FED CTR,MS 413,BOX 25046,LAKEWOOD,CO 80225, USA. NR 0 TC 64 Z9 67 U1 0 U2 7 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 JUL PY 1994 VL 9 IS 4 BP 353 EP 369 DI 10.1016/0883-2927(94)90058-2 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NU143 UT WOS:A1994NU14300001 ER PT J AU MICHEL, RL SCHROEDER, RA AF MICHEL, RL SCHROEDER, RA TI USE OF LONG-TERM TRITIUM RECORDS FROM THE COLORADO RIVER TO DETERMINE TIMESCALES FOR HYDROLOGIC PROCESSES ASSOCIATED WITH IRRIGATION IN THE IMPERIAL-VALLEY, CALIFORNIA SO APPLIED GEOCHEMISTRY LA English DT Article AB Tritium records were used to study hydrologic processes associated with irrigation and drainage in the Imperial Valley, a 2000-km2 agricultural area in the southeastern California desert. Tritium was analyzed in surface water, ground water, soil-pore water and drain water, and the results were compared to the historical record of tritium in the Colorado River. The Colorado River record was reconstructed using a simple reservoir model and precipitation data in the Colorado River Basin for the period prior to 1965, and from continuous measurements in the river for 1965-1988. This historical record is especially useful in the arid Imperial Valley because recent agricultural development has been entirely dependent on irrigation water diverted from the Colorado River and local recharge is negligible. Results indicate that it takes about 5 a for irrigation drainage to move through the soil to a depth of 2-3 m. Drainwaters have a wide range in tritium concentrations because of varying degrees of influence from ground-water intrusion, and from rapid percolation of irrigation through preferred pathways. The net result is that drainwater from about 40 fields had a range in tritium concentration similar to that of the Colorado River OVCT the last 9 a (1980-1988), a period during which tritium concentration was declining about 15% annually in the river. RP MICHEL, RL (reprint author), US GEOL SURVEY,NATL CTR 431,RESTON,VA 22092, USA. NR 0 TC 7 Z9 7 U1 0 U2 1 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 JUL PY 1994 VL 9 IS 4 BP 387 EP 401 DI 10.1016/0883-2927(94)90061-2 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NU143 UT WOS:A1994NU14300004 ER PT J AU WENRICH, KJ AUMENTEMODRESKI, RM AF WENRICH, KJ AUMENTEMODRESKI, RM TI GEOCHEMICAL SOIL SAMPLING FOR DEEPLY-BURIED MINERALIZED BRECCIA PIPES, NORTHWESTERN ARIZONA SO APPLIED GEOCHEMISTRY LA English DT Article AB Thousands of solution-collapse breccia pipes crop out in the canyons and on the plateaus of northwestern Arizona; some host high-grade uranium deposits. The mineralized pipes are enriched in Ag, As, Ba, Co, Cu, Mo, Ni, Pb, Sb, Se, V and Zn. These breccia pipes formed as sedimentary strata collapsed into solution caverns within the underlying Mississippian Redwall Limestone. A typical pipe is approximately 100 m (300 ft) in diameter and extends upward from the Redwall Limestone as much as 1000 m (3000 ft). Unmineralized gypsum and limestone collapses rooted in the Lower Permian Kaibab Limestone or Toroweap Formation also occur throughout this area. Hence, development of geochemical tools that can distinguish these unmineralized collapse structures, as well as unmineralized breccia pipes, from mineralized breccia pipes could significantly reduce drilling costs for these orebodies commonly buried 300-360 m (1000-1200 ft) below the plateau surface. Design and interpretation of soil sampling surveys over breccia pipes are plagued with several complications. (1) The plateau-capping Kaibab Limestone and Moenkopi Formation are made up of diverse lithologies. Thus, because different breccia pipes are capped by different lithologies, each pipe needs to be treated as a separate geochemical survey with its own background samples. (2) Ascertaining true background is difficult because of uncertainties in locations of poorly-exposed collapse cones and ring fracture zones that surround the pipes. Soil geochemical surveys were completed on 50 collapse structures, three of which are known mineralized breccia pipes. Each collapse structure was treated as an independent geochemical survey. Geochemical data from each collapse feature were plotted on single-element geochemical maps and processed by multivariate factor analysis. To contrast the results between geochemical surveys (collapse structures), a means of quantifying the anomalousness of elements at each site was developed. This degree of anomalousness, named the ''correlation value'', was used to rank collapse features by their potential to overlie a deeply-buried mineralized breccia pipe. Soil geochemical results from the three mineralized breccia pipes (the only three of the 50 that had previously been drilled) show that: (1) Soils above the SBF pipe contain significant enrichment of Ag, Al, As, Ba, Ga, K, La, Mo, Nd, Ni, Pb, Sc, Th, U and Zn, and depletion in Ca, Mg and Sr, in contrast to soils outside the topographic and structural rim; (2) Soils over the inner treeless zone of the Canyon pipe show Mo and Pb enrichment and As and Ga depletion, in contrast to soils from the surrounding forest; and (3) The soil survey of the Mohawk Canyon pipe was a failure because of the rocky terrane and lack of a B soil horizon, or because the pipe plunges. At least 11 of the 47 other collapse structures studied contain anomalous soil enrichments similar to the SBF uranium ore-bearing pipe, and thus have good potential as exploration targets for uranium. One of these 11, #1102, does contain surface mineralized rock. These surveys suggest that soil geochemical sampling is a useful tool for the recognition of many collapse structures with underlying ore-bearing breccia pipes. RP WENRICH, KJ (reprint author), US GEOL SURVEY,FED CTR,MS 939,LAKEWOOD,CO 80225, USA. NR 0 TC 1 Z9 1 U1 1 U2 3 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 JUL PY 1994 VL 9 IS 4 BP 431 EP 454 DI 10.1016/0883-2927(94)90065-5 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NU143 UT WOS:A1994NU14300008 ER PT J AU COPLEN, TB HARPER, IT AF COPLEN, TB HARPER, IT TI AN IMPROVED TECHNIQUE FOR THE H-2 H-1 ANALYSIS OF URINES FROM DIABETIC VOLUNTEERS SO BIOLOGICAL MASS SPECTROMETRY LA English DT Article ID WATER; HYDROGEN AB The H-2-H2O ambient-temperature equilibration technique for the determination of H-2/H-1 ratios in urinary waters from diabetic subjects provides improved accuracy over the conventional Zn reduction technique. The standard deviation, similar to 1-2 parts per thousand, is at least a factor of three better than that of the Zn reduction technique on urinary waters from diabetic volunteers. Experiments with pure water and solutions containing glucose, urea and albumen indicate that there is no measurable bias in the hydrogen equilibration technique. C1 NIDDKD,CLIN DIABET & NUTR SECT,PHOENIX,AZ 85016. RP COPLEN, TB (reprint author), US GEOL SURVEY,431 NATL CTR,RESTON,VA 22092, USA. NR 5 TC 17 Z9 17 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1052-9306 J9 BIOL MASS SPECTROM JI Biol. Mass Spectrom. PD JUL PY 1994 VL 23 IS 7 BP 437 EP 439 DI 10.1002/bms.1200230709 PG 3 WC Biophysics; Spectroscopy SC Biophysics; Spectroscopy GA NW622 UT WOS:A1994NW62200008 PM 8068739 ER PT J AU BOWERS, JE DIMMITT, MA AF BOWERS, JE DIMMITT, MA TI FLOWERING PHENOLOGY OF 6 WOODY-PLANTS IN THE NORTHERN SONORAN DESERT SO BULLETIN OF THE TORREY BOTANICAL CLUB LA English DT Article DE PHENOLOGY; SONORAN DESERT; ACACIA-CONSTRICTA; AMBROSIA-DELTOIDEA; CERCIDIUM-MICROPHYLLUM; ENCELIA-FARINOSA; FOUQUIERIA-SPLENDENS; LARREA-TRIDENTATA ID JOJOBA SIMMONDSIA-CHINENSIS; GLANDULOSA VAR TORREYANA; PATTERNS; GROWTH; AVAILABILITY; DORMANCY; SHRUBS AB Climatic and flowering data from a site in the northern Sonoran Desert of southern Arizona were used to define flowering triggers and developmental requirements for 6 woody plants. These formulations were then used to predict flowering dates at a second northern Sonoran Desert site. It was determined that flowering is triggered by rain in Larrea tridentata (DC.) Cov., Fouquieria splendens Engelm., Encelia farinosa A. Gray, Ambrosia deltoidea (A. Gray) Payne and Acacia constricta Benth., and that flowering is triggered by photoperiod in Cercidium microphyllum (Torr.) Rose & Johnst. The base temperature for floral development in L. tridentata, F. splendens, E. farinosa, A. deltoidea and C. microphyllum is about 10-degrees-C. Their mean degree-day requirements range from 414 to 719. Acacia constricta requires 522 degree-days above 15-degrees-C. Minimum rainfall triggers varied from 9 mm for Ambrosia to 20 mm for Encelia. Flowering time in C. microphyllum may reflect phylogenetic constraints, while flowering time in F. splendens may be strongly influenced by pollinator availability. Flowering times of the remaining species seem constrained more by climate than by biotic considerations such as phylogeny, seed germination and competition for pollinators. C1 ARIZONA SONORA DESERT MUSEUM,TUCSON,AZ 85743. RP BOWERS, JE (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 77 TC 54 Z9 58 U1 2 U2 25 PU TORREY BOTANICAL CLUB PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458 SN 0040-9618 J9 B TORREY BOT CLUB JI Bull. Torrey Bot. Club PD JUL-SEP PY 1994 VL 121 IS 3 BP 215 EP 229 DI 10.2307/2997177 PG 15 WC Plant Sciences SC Plant Sciences GA PK885 UT WOS:A1994PK88500001 ER PT J AU PERCIVAL, JA PETERMAN, ZE AF PERCIVAL, JA PETERMAN, ZE TI RB-SR BIOTITE AND WHOLE-ROCK DATA FROM THE KAPUSKASING UPLIFT AND THEIR BEARING ON THE COOLING AND EXHUMATION HISTORY SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article ID U-PB ZIRCON; CHAPLEAU-FOLEYET AREA; SUPERIOR-PROVINCE; STRUCTURAL ZONE; ARCHEAN CRUST; NORTHERN ONTARIO; CANADIAN SHIELD; AGE SPECTRA; AR-40/AR-39; WISCONSIN AB Rb-Sr isotopic ratios were measured on biotite and whole rocks from a suite of 21 granitoid rocks from the southern Kapuskasing uplift. Results of 18 of the whole-rock analyses fall on an isochron with an age of 2.677 +/- 0.057 Ga and Sr-i = 0.70080. Biotite model ages range from 2.50 to 1.93 Ga in a general spatial relationship of decreasing age with depth in the structural section as calibrated with the igneous hornblende barometer for tonalitic rocks and garnet-pyroxene barometers for granulites. Near the Michipicoten belt in the west, biotite ages of similar to 2 Ga reflect disturbances also recorded by paleomagnetic and whole-rock Rb-Sr systems. To the east, in a 70 km long northwest-southeast transect toward the Ivanhoe Lake fault zone, ages decrease from 2.50 to 1.95 Ga. In a southern transect ages are in the range 2.30-2.38 Ga to within 15 km of the fault, reflecting consistent erosion levels corresponding to similar to 0.53 MPa, but decrease to 1.93 Ga to the east, in concert with paleopressures in the 0.7-1.0 GPa range. A plateau of low Rb-Sr biotite dates is not evident, suggesting that the Kapuskasing uplift event exposed a frozen-in cooling profile, rather than setting the Rb-Sr clock by rapid cooling of the rocks from above their closure temperature. The youngest biotite date of 1.93 Ga therefore provides a maximum age for uplift, consistent with paleomagnetic data from Archean rocks and Early Proterozoic dykes, but in conflict with some K-Ar and Ar-40/Ar-39 biotite age data. C1 US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RP PERCIVAL, JA (reprint author), GEOL SURVEY CANADA, 601 BOOTH ST, OTTAWA K1A 0E8, ON, CANADA. NR 72 TC 26 Z9 26 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 JUL PY 1994 VL 31 IS 7 BP 1172 EP 1181 DI 10.1139/e94-103 PG 10 WC Geosciences, Multidisciplinary SC Geology GA PJ580 UT WOS:A1994PJ58000013 ER PT J AU GAGEN, CJ SHARPE, WE CARLINE, RF AF GAGEN, CJ SHARPE, WE CARLINE, RF TI DOWNSTREAM MOVEMENT AND MORTALITY OF BROOK TROUT (SALVELINUS-FONTINALIS) EXPOSED TO ACIDIC EPISODES IN STREAMS SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID LOW PH; ACIDIFICATION; ALUMINUM; RIVER; FISH; AVOIDANCE; SALMON; WATER; AL AB Episodes of low pH and high Al concentration were associated with net downstream movement and increased mortality of ratio-tagged brook trout (Salvelinus fontinalis). We compared movements of 10-15 brook trout in two streams with severe acidic episodes with movements of fish in two streams with less severe acidic episodes (reference streams). Study populations moved downstream hundreds of metres in the streams with more severe acidic episodes (pH <5.0 and >200 mu g Al/L). Median downstream movement in spring was 250 and 900 m after 20 d for fish in the more acidic streams; one third of the fish were found dead during this time. We found no net movement and no dead fish in the reference streams. Lower stream discharge in fall studies was associated with less severe acidic episodes, less net movement, and no mortality. Water samples collected at individual fish locations indicated that few fish avoided adverse effects of acidic episodes by remaining in microhabitats with higher pH and lower Al concentration. C1 PENN STATE UNIV,ENVIRONM RESOURCES RES INST,UNIVERSITY PK,PA 16802. PENN STATE UNIV,ECOL PROGRAM,UNIVERSITY PK,PA 16802. PENN STATE UNIV,US FISH & WILDLIFE SERV,PENN COOPERAT FISH & WILDLIFE RES UNIT,UNIVERSITY PK,PA 16802. NR 33 TC 21 Z9 21 U1 1 U2 4 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 JUL PY 1994 VL 51 IS 7 BP 1620 EP 1628 DI 10.1139/f94-162 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA PP189 UT WOS:A1994PP18900017 ER PT J AU ACKERMAN, JD SIM, B NICHOLS, SJ CLAUDI, R AF ACKERMAN, JD SIM, B NICHOLS, SJ CLAUDI, R TI REVIEW OF THE EARLY-LIFE HISTORY OF ZEBRA MUSSELS (DREISSENA-POLYMORPHA) - COMPARISONS WITH MARINE BIVALVES SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Review ID EARLY DEVELOPMENTAL STAGES; MYTILUS-EDULIS; GREAT-LAKES; LARVAL; DISPERSAL; POPULATIONS; SETTLEMENT; ABUNDANCE; DYNAMICS; MOLLUSK AB The ecological and economic impacts of the introduced zebra mussel (Dreissena polymorpha (Pallas)) have been due in part to a life history that is conserved with marine bivalves but unique among the indigenous freshwater fauna. There are a number of life history events in D. polymorpha that follow external fertilization and embryology. The first is a brief trochophore stage. The development of a velum and secretion of a larval shell lead to a D-shaped veliger, which is the first recognizable planktonic larva. Later a second larval shell is secreted and this veliconcha is the last obligate free-swimming veliger. Conversely, the last larval stage, the pediveliger, can either swim using its velum or crawl using its foot. Pediveligers select substrates on which they ''settle'' by secreting byssal threads and undergo metamorphosis to become plantigrade mussels. The secretion of the adult shell and change in growth axis lead to the convergent heteromyarian shape. Zebra mussels produce byssal threads as adults, but these attachments may be broken, enabling the mussels to translocate to new areas. The recognition of these life history features will lead to a better understanding of zebra mussel biology. In summary, life history stages of zebra mussels are similar to those of marine bivalves and should be identified morphologically rather than on the basis of size. C1 ROYAL ONTARIO MUSEUM,DEPT INVERTEBRATE ZOOL,TORONTO M5S 2C6,ON,CANADA. ONTARIO HYDRO,BIOL RES SECT,TORONTO M8Z 5S4,ON,CANADA. US FISH & WILDLIFE SERV,ANN ARBOR,MI 48105. ONTARIO HYDRO,DEPT ENVIRONM PROTECT,TORONTO M5G 1X6,ON,CANADA. OI Ackerman, Josef/0000-0003-4550-490X NR 94 TC 80 Z9 81 U1 2 U2 44 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 JUL PY 1994 VL 72 IS 7 BP 1169 EP 1179 DI 10.1139/z94-157 PG 11 WC Zoology SC Zoology GA PT900 UT WOS:A1994PT90000001 ER PT J AU SIDDER, GB AF SIDDER, GB TI PETRO-CALC PLOT, MICROSOFT EXCEL MACROS TO AID PETROLOGIC INTERPRETATION SO COMPUTERS & GEOSCIENCES LA English DT Article DE MACROS; RECALCULATION; PETROLOGY; X-Y GRAPHS; TERNARY DIAGRAMS ID VOLCANIC ROCK SERIES; CHEMICAL CLASSIFICATION; DIAGRAM; BASALTS; ARC AB PETRO.CALC.PLOT is a package of macros which normalizes whole-rock oxide data to 100%, calculates the cation percentages and molecular proportions used for normative mineral calculations, computes the apices for ternary diagrams, determines sums and ratios of specific elements of petrologic interest, and plots 33 X- Y graphs and five ternary diagrams. PETRO.CALC.PLOT also may be used to create other diagrams as desired by the user. The macros run in Microsoft Excel 3.0 and 4.0 for Macintosh computers and in Microsoft Excel 3.0 and 4.0 for Windows. Macros provided in PETRO.CALC.PLOT minimize repetition and time required to recalculate and plot whole-rock oxide data for petrologic analysis. RP SIDDER, GB (reprint author), US DEPT INTERIOR,US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS-905,DENVER,CO 80225, USA. NR 34 TC 9 Z9 9 U1 0 U2 2 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 JUL PY 1994 VL 20 IS 6 BP 1041 EP 1061 DI 10.1016/0098-3004(94)90040-X PG 21 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA PC943 UT WOS:A1994PC94300006 ER PT J AU TAUXE, L GEE, J GALLET, Y PICK, T BOWN, T AF TAUXE, L GEE, J GALLET, Y PICK, T BOWN, T TI MAGNETOSTRATIGRAPHY OF THE WILLWOOD FORMATION, BIGHORN BASIN, WYOMING - NEW CONSTRAINTS ON THE LOCATION OF PALEOCENE EOCENE BOUNDARY SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID MAGNETIC POLARITY STRATIGRAPHY; ALLUVIAL PALEOSOLS; PALEOMAGNETIC DATA; NORTH-AMERICA; LONDON BASINS; GOBAN SPUR; INTEGRATION; SEDIMENTS; HAMPSHIRE; DEPOSITS AB The lower Eocene Willwood Formation in the Bighorn Basin of Wyoming preserves a rich and diverse mammalian and floral record. The paleomagnetic behavior of the sequence of floodplain paleosols of varying degrees of maturation ranges from excellent to poor. We present a magnetostratigraphic section for a composite section near Worland, Wyoming, by using a set of strict criteria for interpreting the step-wise alternating field and thermal demagnetization data of 266 samples from 90 sites throughout the composite section. Correlation to the geomagnetic reversal time scale was achieved by combining magnetostratigraphic and biostratigraphic data from this section, from a section in the Clark's Fork Basin in northern Wyoming, and from DSDP Site 550, with the isotopic date determined on a tuff near the top of our section. Our correlation suggests that the Bighorn Basin composite section in the Worland area spans from within Chron C24r to near the top of Chron C24n, or from approximately 55 to 52 Ma. This correlation places the Paleocene/Eocene boundary within the vicinity of the base of the section. Cryptochron C24r.6 of Cande and Kent is tentatively identified some 100 m above the base of the section. The temporal framework provided here enables correlation of the mammalian biostratigraphy of the Bighorn Basin to other continental sequences as well as to marine records. It also provides independent chronological information for the calculation of sediment accumulation rates to constrain soil maturation rates. We exclude an age as young as 53 Ma for the Paleocene/Eocene boundary and support older ages, as recommended in recent time scales. The location of a tuff dated at 52.8 +/- 0.3 Ma at the older boundary C24n.1 is consistent with the, age of 52.5 Ma estimated by Cande and Kent and inconsistent with that of 53.7 Ma, from Harland et al. C1 UNIV UTRECHT,FORT HOOFDDIJK PALEOMAGNET LAB,3584 CD UTRECHT,NETHERLANDS. LAMONT DOHERTY EARTH OBS,PALISADES,NY. US GEOL SURVEY,DENVER,CO 80225. UNIV PARIS 06,INST PHYS GLOBE,F-75230 PARIS 05,FRANCE. RP TAUXE, L (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 32 TC 32 Z9 32 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 1994 VL 125 IS 1-4 BP 159 EP 172 DI 10.1016/0012-821X(94)90213-5 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC442 UT WOS:A1994PC44200011 ER PT J AU ROSENBERG, DK ZABEL, CJ NOON, BR MESLOW, EC AF ROSENBERG, DK ZABEL, CJ NOON, BR MESLOW, EC TI NORTHERN SPOTTED OWLS - INFLUENCE OF PREY BASE - A COMMENT SO ECOLOGY LA English DT Note ID WESTERN OREGON; FLUCTUATIONS; ENUMERATION; POPULATIONS; RECAPTURE; FORESTS C1 US FOREST SERV,REDWOOD SCI LAB,ARCATA,CA 95521. OREGON STATE UNIV,US FISH & WILDLIFE SERV,COOPERAT WILDLIFE RES UNIT,CORVALLIS,OR 97331. NR 18 TC 9 Z9 10 U1 0 U2 3 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 1994 VL 75 IS 5 BP 1512 EP 1515 DI 10.2307/1937475 PG 4 WC Ecology SC Environmental Sciences & Ecology GA NV662 UT WOS:A1994NV66200030 ER PT J AU LOVLEY, DR CHAPELLE, FH WOODWARD, JC AF LOVLEY, DR CHAPELLE, FH WOODWARD, JC TI USE OF DISSOLVED H(2) CONCENTRATIONS TO DETERMINE DISTRIBUTION OF MICROBIALLY CATALYZED REDOX REACTIONS IN ANOXIC GROUNDWATER SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID COASTAL-PLAIN AQUIFER; IRON REDUCTION; SULFATE REDUCTION; INORGANIC CARBON; SEDIMENTS; WATER; GEOCHEMISTRY; ENVIRONMENT; INHIBITION; OXIDATION AB The potential for using concentrations of dissolved H-2 to determine the distribution of redox processes in anoxic groundwaters was evaluated. In pristine aquifers in which standard geochemical measurements indicated that Fe(III) reduction, sulfate reduction, or methanogenesis was the terminal electron accepting process (TEAP), the H-2 concentrations were similar to the H-2 concentrations that have previously been reported for aquatic sediments with the same TEAPs. In two aquifers contaminated with petroleum products, it was impossible with standard geochemical analyses to determine which TEAPs predominated in specific locations. However, the TEAPs predicted from measurements of dissolved H-2 were the same as those determined directly through measurements of microbial processes in incubated aquifer material. These results suggest that H-2 concentrations may be a useful tool for analyzing the redox chemistry of nonequilibrium groundwaters. C1 US GEOL SURVEY,DIV WATER RESOURCES,COLUMBIA,SC 29210. RP LOVLEY, DR (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,430 NATL CTR,RESTON,VA 22092, USA. NR 28 TC 138 Z9 140 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUL PY 1994 VL 28 IS 7 BP 1205 EP 1210 DI 10.1021/es00056a005 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA NU808 UT WOS:A1994NU80800006 PM 22176309 ER PT J AU BUERGER, TT MORTENSEN, SR KENDALL, RJ HOOPER, MJ AF BUERGER, TT MORTENSEN, SR KENDALL, RJ HOOPER, MJ TI METABOLISM AND ACUTE TOXICITY OF METHYL PARATHION IN PEN-REARED AND WILD NORTHERN BOBWHITES SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE ACUTE TOXICITY; CHOLINESTERASE; COLINUS-VIRGINIANUS; METABOLISM; METHYL PARATHION ID BRAIN CHOLINESTERASE ACTIVITY; INSECTICIDES; PESTICIDES; BIRDS; ACETYLCHOLINESTERASE; PREDATION; RECOVERY; ENZYMES AB Pesticide registration guidelines in the United States accept pen-reared northern bobwhites (Colinus virginianus) for acute toxicity testing and consider them representative of wild terrestrial birds. It is not known how well the various pen-reared bobwhite strains represent their wild counterpart. The metabolic activation, cholinesterase sensitivity, and toxicity of the organophosphorus insecticide methyl parathion were compared in pen-reared and wild bobwhites. Phosphorothioate insecticides such as methyl parathion are activated to their anticholinesterase oxygen analogues (oxons) by microsomal monooxygenases. Methyl paraoxon 150 values for whole-brain cholinesterase were similar (P > 0.05) for pen-reared and wild bobwhites (60.0-65.1 nM). Activation of methyl parathion to methyl paraoxon by liver microsomes was measured indirectly by inhibition of brain cholinesterase. Microsomal specific activities were similar (P > 0.05) for male and female pen-reared and wild birds (1.15-1.54 nmol min-1 mg protein-1). There were no differences (P > 0.05) in LD50 values between pen-reared (9.84 mg/kg) and wild (10.22 mg/kg) bobwhites. Brain cholinesterase was depressed 70 to 85% in nonsurvivors and 23 to 35% in survivors. Results suggest that pen-reared bobwhites are representative of wild bobwhites. However, comparisons with our previous field research demonstrate that sublethal effects seen in the lab can become lethal under natural conditions. Extrapolations from lab to field must be made cautiously. C1 CLEMSON UNIV,DEPT ENVIRONM TOXICOL,PENDLETON,SC 29670. CLEMSON UNIV,INST WILDLIFE & ENVIRONM TOXICOL,PENDLETON,SC 29670. US FISH & WILDLIFE SERV,911 NE 11TH AVE,PORTLAND,OR 97232. OI Hooper, Michael/0000-0002-4161-8961 NR 40 TC 3 Z9 3 U1 0 U2 2 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 1994 VL 13 IS 7 BP 1139 EP 1143 DI 10.1897/1552-8618(1994)13[1139:MAATOM]2.0.CO;2 PG 5 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT241 UT WOS:A1994NT24100015 ER PT J AU WATZIN, MC ROSCIGNO, PF BURKE, WD AF WATZIN, MC ROSCIGNO, PF BURKE, WD TI COMMUNITY-LEVEL FIELD METHOD FOR TESTING THE TOXICITY OF CONTAMINATED SEDIMENTS IN ESTUARIES SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE AQUATIC TOXICOLOGY; ARTIFICIAL SEDIMENT; BENTHIC RECRUITMENT; ZINC; MOBILE BAY ID MACROFAUNA; MEIOFAUNA; ECOLOGY; WATER AB The objective of this study was to demonstrate a method for testing the toxicity of contaminated sediments under field conditions. An artificial sediment that matches field sediment in grain-size distribution and organic matter content was mixed from 11 components and used as the test substrate. Clean sediments and sediments spiked with zinc (approximately 8,000 mg/kg) were exposed in the field on a holding rack anchored on the bottom of Mobile Bay, Alabama. The abundance and diversity (species richness) of benthic invertebrate recruits were used as indicators of sediment quality. The number of recruits was significantly reduced by the presence of zinc in one-week exposures. C1 US FISH & WILDLIFE SERV, NATL WETLANDS RES CTR, LAFEYETTE, LA 70506 USA. GULF COAST RES LAB, OCEAN SPRINGS, MS 39564 USA. UNIV VERMONT, NATL BIOL SURVEY, BURLINGTON, VT 05405 USA. NR 33 TC 16 Z9 16 U1 0 U2 3 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 JUL PY 1994 VL 13 IS 7 BP 1187 EP 1193 DI 10.1897/1552-8618(1994)13[1187:CFMFTT]2.0.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NT241 UT WOS:A1994NT24100020 ER PT J AU CASTILLO, GC LI, HW GOLDEN, JT AF CASTILLO, GC LI, HW GOLDEN, JT TI ENVIRONMENTALLY-INDUCED RECRUITMENT VARIATION IN PETRALE SOLE, EOPSETTA-JORDANI SO FISHERY BULLETIN LA English DT Article ID COASTAL OCEAN; OREGON; SCALE; TESTS AB Potential effects of parental stock size and environmental factors on year-class strength (YCS) of petrale sole, Eopsetta jordani, were investigated in two areas off Oregon and Washington (Pacific States Marine Fisheries Commission areas 2B: 42-degrees-50'N-44-degrees-18'N, and 3A: 45-degrees-46'N-47-degrees-20'N). Parental egg production indices and YCS were not consistently correlated over the period 1970 to 1977. Variation in YCS between 1958 and 1977 was associated with oceanographic conditions from winter to early spring, the period in which pelagic larval stages are most abundant. A regression model based on indices of offshore Ekman transport from January to March and alongshore transport from December to February accounted for nearly 55% of the YCS variation in Area 2B. In Area 3A, the previous two indices plus sea surface temperature from December to February explained about 65% of the YCS variation. Inshore advection of eggs and larvae could favor settlement of juveniles into nearshore areas and increase the subsequent recruitment strength of petrale sole. C1 OREGON DEPT FISH & WILDLIFE,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. RP CASTILLO, GC (reprint author), OREGON STATE UNIV,DEPT FISHERIES & WILDLIFE,US FISH & WILDLIFE SERV,CORVALLIS,OR 97331, USA. NR 52 TC 7 Z9 7 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JUL PY 1994 VL 92 IS 3 BP 481 EP 493 PG 13 WC Fisheries SC Fisheries GA NX911 UT WOS:A1994NX91100002 ER PT J AU BARKATT, A SANG, JC THORPE, AN SENFTLE, FE TALMY, IG NORR, MK MAZER, JJ IZETT, G SIGURDSSON, H AF BARKATT, A SANG, JC THORPE, AN SENFTLE, FE TALMY, IG NORR, MK MAZER, JJ IZETT, G SIGURDSSON, H TI SURFACE ALTERATION AND PHYSICAL-PROPERTIES OF GLASS FROM THE CRETACEOUS-TERTIARY BOUNDARY SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HAITI; IMPACT; TEKTITES AB The scalloped surface feature on Cretaceous-Tertiary boundary glass is often explained as being due to terrestrial aqueous leaching. Leaching of man-made glass results in a reduction in density of the glass. Also, Fe, because of its relative insolubility, is concentrated by the leaching process. Thus, the Haitian glass specimens which have been heavily altered should have a thin rim of less dense glass in which the Fe is concentrated compared to the core glass. The higher Fe concentration in the rim glass should cause it to have an enhanced Curie constant and a lower density compared to the unaltered glass. The magnetic Curie constant, density, and scanning electron microscopic studies were made on altered specimens of Haitian glass and also on specimens showing a minimum of alteration. The results show that the less altered samples have the highest density and the lowest Curie constant. The data substantiate the terrestrial hypothesis. C1 HOWARD UNIV,WASHINGTON,DC 20059. USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20910. ARGONNE NATL LAB,ARGONNE,IL 60439. US GEOL SURVEY,DENVER,CO 80225. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. RP BARKATT, A (reprint author), CATHOLIC UNIV AMER,WASHINGTON,DC 20064, USA. NR 10 TC 2 Z9 2 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 JUL PY 1994 VL 58 IS 13 BP 2889 EP 2891 DI 10.1016/0016-7037(94)90122-8 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NX237 UT WOS:A1994NX23700011 ER PT J AU ELDER, WP GUSTASON, ER SAGEMAN, BB AF ELDER, WP GUSTASON, ER SAGEMAN, BB TI CORRELATION OF BASINAL CARBONATE CYCLES TO NEARSHORE PARASEQUENCES IN THE LATE CRETACEOUS GREENHORN SEAWAY, WESTERN INTERIOR USA SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID UNITED-STATES; CLIMATE; LEVEL; SEDIMENTATION; SEQUENCES; PATTERNS; COLORADO; PUEBLO; AREAS AB Upper Cretaceous limestone-shale couplets developed within the late transgressive stage of the Greenhorn cyclothem may be correlated from carbonate-dominated (basinal) sequences in central Kansas and Colorado westward to clastic cycles in southern Utah. Six such basinal couplets have been traced to corresponding upward-coarsening progradational cycles developed on the western margin of the Western Interior basin. In the central basin in Colorado and Kansas, these sedimentary cycles are represented by limestone-shale and maristone-shale couplets approximately 0.5-1.0 m in thickness. More calcareous parts of these couplets may be correlated westward into condensed, fossiliferous concretion and shell beds in proximal offshore lithofacies of Arizona and Utah. These concretion and shell beds are physically traceable farther landward (westward) into bioturbated, fossil-rich, transgressive lag deposits that bound 10- to 20-m-thick coarsening-upward progradational strand-plain deposits (parasequences) in southwestern Utah. Thus, the progradational phase of parasequence deposition correlates with accumulation of clay-rich sediment in the central basin, and the transgressive phase is characterized by reduced terrigenous input and deposition of carbonate-rich sediment. We consider Milankovitch-style orbital forcing of climate and tectonically induced fluctuations in rates of foredeep basin subsidence as possible forcing mechanisms for these basinwide events. Based on the widespread distribution of the limestone-shale couplets, as well as on estimated sedimentation rates and geochronology, it has been widely speculated that these carbonate cycles reflect Milankovitch cycles with periodicities on the order of 20 k.y. to 100 ky. If so, then stratigraphic data suggest that orbital forcing of climate affected eustasy and/or sediment input and biogenic production in the Western Interior basin. Alternatively, thrusting events in the Sevier orogenic belt may have produced episodic changes in the rates of foredeep basin subsidence and consequent changes in base level, which could have controlled the deposition of the Greenhorn parasequences and carbonate cycles. In either case, correlation of these units demonstrates a consistent basinwide sedimentary response to high-frequency base level or sediment input changes in the Western Interior epicontinental basin. C1 BP EXPLORAT ALASKA INC,ANCHORAGE,AK 99519. NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60208. RP ELDER, WP (reprint author), US GEOL SURVEY,MS 915,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Sageman, Bradley/E-6363-2010 NR 43 TC 69 Z9 70 U1 1 U2 8 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 JUL PY 1994 VL 106 IS 7 BP 892 EP 902 DI 10.1130/0016-7606(1994)106<0892:COBCCT>2.3.CO;2 PG 11 WC Geosciences, Multidisciplinary SC Geology GA NU821 UT WOS:A1994NU82100004 ER PT J AU MOORE, JG BRYAN, WB LUDWIG, KR AF MOORE, JG BRYAN, WB LUDWIG, KR TI CHAOTIC DEPOSITION BY A GIANT WAVE, MOLOKAI, HAWAII SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article AB A coral-basalt breccia-conglomerate is exposed >60 m above present sea level and nearly 2 km inland from the present shoreline on the southwest side of East Molokai Volcano, Molokai. The conglomerate is preserved mantling interfluves between gullies and forms a blanket-like deposit 0.5 to 3 m thick. No evidence of a wavecut terrace either within the blanket or at its upper or lower limits of exposure can be found. No coral was found in growth position. Unsorted basalt clasts as large as boulder size are subrounded to angular, randomly oriented, and vary from 2-3 to >50 volume% of the deposit. The size of the largest basalt and coral fragments shows almost no systematic variation with elevation, distance inland, or lateral position parallel to the shore. Two indistinct rock units are present in a few places, a lower carbonate-rich unit that we interpret as an ''onwash facies'' and an upper basalt-rich unit, an ''offwash facies.'' The carbonate-rich onwash facies is dominated by biogenic debris, especially fragments of coral and beach rock and gastropod and bivalve shells. The offwash facies contains 40% to >90% basalt cobbles and boulders in a matrix of finely broken biogenic fragments. Where the distinct facies are lacking, the proportion of basalt clasts increases crudely from the lower to the upper part of the conglomerate at a single place and from lower to higher elevation outcrops. Where the deposit overlies a cinder cone, several carbonate-bearing clastic dikes extend from the conglomerate as much as 10 m down into the basalt cinders. This deposit was apparently laid down by a giant wave that broke over an outer reef, similar to the present fringing reef, and advanced as a turbulent bore over the back-reef flat, picking up a slurry of carbonate-rich debris and depositing it on the slopes inland as the wave advanced. The offwash picked up loose basalt debris on its return flow. U-series dating of coral fragments indicates that the age of this deposit is 240-200 ka, indicating the wave is distinct from that which produced a similar deposit on Lanai about 100 ka. This giant wave was most likely caused by one of the many large submarine landslides that have been identified on the lower slopes of the major Hawaiian Islands. C1 US GEOL SURVEY,DENVER,CO 80225. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. RP MOORE, JG (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 12 TC 50 Z9 50 U1 0 U2 5 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 JUL PY 1994 VL 106 IS 7 BP 962 EP 967 DI 10.1130/0016-7606(1994)106<0962:CDBAGW>2.3.CO;2 PG 6 WC Geosciences, Multidisciplinary SC Geology GA NU821 UT WOS:A1994NU82100010 ER PT J AU BEHRENDT, JC COOPER, AK AF BEHRENDT, JC COOPER, AK TI MINIMAL PLIOCENE-PLEISTOCENE UPLIFT OF THE DRY VALLEYS SECTOR OF THE TRANSANTARCTIC MOUNTAINS - A KEY PARAMETER IN ICE-SHEET RECONSTRUCTIONS - COMMENT SO GEOLOGY LA English DT Note C1 US GEOL SURVEY,MENLO PK,CA 94025. RP BEHRENDT, JC (reprint author), US GEOL SURVEY,MS 964,FED CTR,DENVER,CO 80225, USA. NR 10 TC 5 Z9 5 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 JUL PY 1994 VL 22 IS 7 BP 668 EP 669 DI 10.1130/0091-7613(1994)022<0668:MPPUOT>2.3.CO;2 PG 2 WC Geology SC Geology GA NU819 UT WOS:A1994NU81900026 ER PT J AU WILLIAMS, SDP SVARC, JL LISOWSKI, M PRESCOTT, WH AF WILLIAMS, SDP SVARC, JL LISOWSKI, M PRESCOTT, WH TI GPS MEASURED RATES OF DEFORMATION IN THE NORTHERN SAN-FRANCISCO BAY-REGION, CALIFORNIA, 1990-1993 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GLOBAL POSITIONING SYSTEM; CRUSTAL DEFORMATION AB A 100-km-long, 13-station profile extending across the San Andreas fault system north of San Francisco Bay was measured 7 times between March 1990 and January 1993 with the Global Positioning System (GPS). The data have been processed using the Bernese Version 3.2 software. Data from a continental-scale fiducial network were included in the solutions to aid orbit improvement and provide a consistent reference frame. We find 33+/-2 mm/yr of fault-parallel (N33-degrees-W) shear evenly distributed southwest and northeast of the Rodgers Creek fault and a near linear velocity gradient across the profile. The profile spans most of the zone of active deformation associated with the San Andreas fault system. Shear is negligible at the east end of the profile near the Great Valley. Additional shear of a few millimeters per year is likely beyond Point Reyes Head, the west end of the profile. We observe no systematic convergence upon the fault. The GPS measured velocities are similar to those derived previously from trilateration. The velocity change across the GPS profile (31-35 mm/yr) plus that west of the profile (0-3 mm/yr) and that observed with VLBI east of the Sierra Nevada Mountains (approximately 10-12 mm/yr) accounts for the North American-Pacific plate rate (46-47 mm/yr). C1 US GEOL SURVEY,MENLO PK,CA 94025. RI Williams, Simon/C-7214-2011 OI Williams, Simon/0000-0003-4123-4973 NR 11 TC 9 Z9 9 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 JUL 1 PY 1994 VL 21 IS 14 BP 1511 EP 1514 DI 10.1029/94GL01227 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NV986 UT WOS:A1994NV98600006 ER PT J AU OREMLAND, RS BOONE, DR AF OREMLAND, RS BOONE, DR TI METHANOLOBUS TAYLORII SP-NOV, A NEW METHYLOTROPHIC, ESTUARINE METHANOGEN SO INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY LA English DT Note ID DIMETHYL SULFIDE; ANOXIC SEDIMENTS; SULFUR-COMPOUNDS; METHANOHALOPHILUS AB Previously published phylogenetic studies of 16S rRNA showed that methylotrophic, slightly halophilic, methanogenic strain GS-16(T) (T = type strain) represents a new species of bacterium. We propose the name Methanolobus taylorii for this species; strain GS-16 is the type strain. C1 OREGON GRAD INST SCI & TECHNOL,DEPT ENVIRONM SCI & ENGN,PORTLAND,OR 97291. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. NR 18 TC 34 Z9 34 U1 1 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0020-7713 J9 INT J SYST BACTERIOL JI Int. J. Syst. Bacteriol. PD JUL PY 1994 VL 44 IS 3 BP 573 EP 575 PG 3 WC Microbiology SC Microbiology GA NW043 UT WOS:A1994NW04300027 ER PT J AU LONGBOTTOM, JE MARTIN, TD EDGELL, KW LONG, SE PLANTZ, MR WARDEN, BE BARAONA, R BENCIVENGO, D CARDENAS, D FAIRES, L GERLACH, D KING, W LAING, G LORD, C PLANTZ, M RETTBERG, T TAN, S TYE, D WALLACE, G AF LONGBOTTOM, JE MARTIN, TD EDGELL, KW LONG, SE PLANTZ, MR WARDEN, BE BARAONA, R BENCIVENGO, D CARDENAS, D FAIRES, L GERLACH, D KING, W LAING, G LORD, C PLANTZ, M RETTBERG, T TAN, S TYE, D WALLACE, G TI DETERMINATION OF TRACE-ELEMENTS IN WATER BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY - COLLABORATIVE STUDY SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article AB A joint U.S. Environmental Protection Agency (U.S. EPA)-AOAC interlaboratory method validation study was conducted on U.S. EPA method 200.8, Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry. The purpose of the study was to determine and compare the mean recovery and precision of the inductively coupled plasma-mass spectrometry (ICP-MS) analyses for 20 trace elements in reagent water, drinking water, and ground-water. The formal study was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The test waters were spiked with the 20 trace elements at 6 concentration levels in the 0.8-200 mug/L range, prepared as 3 Youden pairs. Thirteen collaborators spiked 100 mL aliquots of the test waters, acidified them with 1 mL concentrated HN03 and 0.5 mL concentrated HCl, reduced the volume to 20 mL by heating in an open beaker at 85-degrees-C, refluxed them for 30 min at 95-degrees-C, and diluted them to 50 mL. After centrifuging or settling the samples, a 20 mL portion of the supernatant was diluted to 50 mL and analyzed by ICP-MS. Related experiments evaluated the method performance in wastewater and wastewater digestate at a single concentration pair, and an alternative nitric acid digestion procedure. Mean recoveries for reagent water, drinking water, and groundwater were generally 95-105% with between-laboratory relative standard deviations about 4-8%. The method also worked well with wastewaters and digestate, with between-laboratory relative standard deviations averaging 8% and recoveries averaging 100%. Recoveries of silver, however, were low in all matrixes at concentrations over 100 mug/L. The nitric acid digestion procedure was comparable in accuracy and precision to the mixed-acid digestion in U.S. EPA method 200.8. The method was adopted first action by AOAC INTERNATIONAL. C1 BIONET CORP,CINCINNATI,OH 45246. TECHNOL APPLICAT INC,CINCINNATI,OH 45268. WMI ENVIRONM MONITORING LABS,GENEVA,IL. LOCKHEED ENGN & SCI,HOUSTON,TX. US GEOL SURVEY,WASHINGTON,DC 20242. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. PENN BUR LABS,HARRISBURG,PA. PHILLIPS PETR CO,BARTLESVILLE,OK 74004. VG INSTRUMENTS,DANVERS,MA. PERKIN ELMER CORP,NORWALK,CT 06856. RP LONGBOTTOM, JE (reprint author), US EPA,26 W MARTIN LUTHER KING DR,CINCINNATI,OH 45268, USA. NR 12 TC 23 Z9 23 U1 0 U2 12 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD JUL-AUG PY 1994 VL 77 IS 4 BP 1004 EP 1023 PG 20 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA NY376 UT WOS:A1994NY37600041 ER PT J AU BISCHOFF, JL LUDWIG, K GARCIA, JF CARBONELL, E VAQUERO, M STAFFORD, TW JULL, AJT AF BISCHOFF, JL LUDWIG, K GARCIA, JF CARBONELL, E VAQUERO, M STAFFORD, TW JULL, AJT TI DATING OF THE BASAL AURIGNACIAN SANDWICH AT ABRIC-ROMANI (CATALUNYA, SPAIN) BY RADIOCARBON AND URANIUM-SERIES SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Article ID TOTAL-SAMPLE DISSOLUTION; AGE AB Abric Romani, a rock shelter located near Barcelona, Spain, contains a charcoal-bearing basal Aurignacian occupation level sandwiched between beds of moss-generated carbonate. The Aurignacian culture is the oldest artefact industry in Europe with which anatomically modem human remains have been associated. Radiocarbon analysis of charcoal fragments by accelerator mass spectrometry (AMS) dates the basal Aurignacian to about 37 +/- 2 ka bp. U-series analyses by alpha spectrometry (AS) and mass spectrometry (MS) date the enclosing carbonate to 43 +/- 1 ka bp. These results confirm the great antiquity of the Aurignacian in northern Spain and support the similar AMS dates from El Castillo and l'Arbreda caves. They also show that radiocarbon dates are significantly younger than U-series at 40 ka bp, as predicted by theory. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. UNIV BARCELONA,DEPT ANALYT CHEM,E-08028 BARCELONA,SPAIN. UNIV BARCELONA,ARCHEOL SECT,E-42006 TARAGONA,SPAIN. UNIV COLORADO,INSTAAR,BOULDER,CO 80309. UNIV ARIZONA,NSF ACCELERATOR FACIL,TUCSON,AZ 85721. RP BISCHOFF, JL (reprint author), US GEOL SURVEY,MAIL STOP 999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 32 TC 81 Z9 81 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD JUL PY 1994 VL 21 IS 4 BP 541 EP 551 DI 10.1006/jasc.1994.1053 PG 11 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA PB263 UT WOS:A1994PB26300012 ER PT J AU WERSHAW, RL AIKEN, GR IMBRIGIOTTA, TE GOLDBERG, MC AF WERSHAW, RL AIKEN, GR IMBRIGIOTTA, TE GOLDBERG, MC TI DISPLACEMENT OF SOIL PORE-WATER BY TRICHLOROETHYLENE SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID HUMIC-ACID FRACTIONS AB Dense nonaqueous phase liquids (DNAPLS) are important pollutants because of their widespread use as chemical and industrial solvents. An example of the pollution caused by the discharge of DNAPLs is found at the Picatinny Arsenal, New Jersey, where trichloroethylene (TCE) has been discharged directly into the unsaturated zone. This discharge has resulted in the formation of a plume of TCE-contaminated water in the aquifer downgradient of the discharge. A zone of dark-colored groundwater containing a high dissolved organic C content has been found near the point of discharge of the TCE. The colored-water plume extends from the point of discharge at least 30 m (100 feet) downgradient. Fulvic acids isolated from the colored-waters plume, from water from a background well that has not been affected by the discharge of chlorinated solvents, and from soil pore water collected in a lysimeter installed at an uncontaminated site upgradient of the study area have been compared. Nuclear magnetic resonance spectra of the fulvic acids from the colored waters and from the lysimeter are very similar, but are markedly-different from the nuclear magnetic resonance spectrum of the fulvic acid from the background well. The three-dimensional fluorescence spectrum and the DOC fractionation profile of the colored groundwater and the soil pore water are very similar to each other, but quite different from those of the background water. It is proposed from these observations that this colored water is soil pore water that has been displaced by a separate DNAPL liquid phase downward to the saturated zone. C1 US GEOL SURVEY, DIV WATER RESOURCES, W TRENTON, NJ 08628 USA. RP WERSHAW, RL (reprint author), US GEOL SURVEY, DENVER FED CTR, DIV WATER RESOURCES, POB 25046, MAIL STOP 408, DENVER, CO 80225 USA. NR 14 TC 1 Z9 1 U1 1 U2 6 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 EI 1537-2537 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JUL-AUG PY 1994 VL 23 IS 4 BP 792 EP 798 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA NW830 UT WOS:A1994NW83000024 ER PT J AU MEYER, W SCHUSTER, RL SABOL, MA AF MEYER, W SCHUSTER, RL SABOL, MA TI POTENTIAL FOR SEEPAGE EROSION OF LANDSLIDE DAM SO JOURNAL OF GEOTECHNICAL ENGINEERING-ASCE LA English DT Article AB The failure potential of the debris-avalanche dam at Castle Lake near Mount St. HelenS, Washington, by three processes of seepage erosion: (1) Heave; (2) piping; and (3) internal erosion, is examined. A three-dimensional groundwater model of the dam was constructed and used in conjunction with properties of the blockage material to examine the dam's stability against failure by heave and piping, Results indicated that the dam is stable against piping but potentially locally unstable against heave. Comparison of physical properties of the blockage materials with critical physical properties for embankment dams that have experienced distress because of internal erosion shows the blockage to be marginally stable against internal erosion. A ground-water mound as much as 10 m (35 ft) above lake level formed in the dam and is responsible for creating vertical hydraulic gradients capable of inducing heave. Similar mounds may exist in embankment dams of comparable geometry and hydraulic conductivity. C1 US GEOL SURVEY,DENVER,CO 80225. US EPA,SEATTLE,WA 98101. RP MEYER, W (reprint author), US GEOL SURVEY,677 ALA MOANA BLVD,STE 415,HONOLULU,HI 96813, USA. NR 29 TC 14 Z9 17 U1 2 U2 8 PU ASCE-AMER SOC CIVIL ENGINEERS 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 JUL PY 1994 VL 120 IS 7 BP 1211 EP 1229 DI 10.1061/(ASCE)0733-9410(1994)120:7(1211) PG 19 WC Engineering, Civil; Geosciences, Multidisciplinary SC Engineering; Geology GA NT549 UT WOS:A1994NT54900007 ER PT J AU CHRISTIAN, EJ AF CHRISTIAN, EJ TI HELPING THE PUBLIC FIND INFORMATION - THE UNITED-STATES GOVERNMENT-INFORMATION-LOCATOR-SERVICE (GILS) SO JOURNAL OF GOVERNMENT INFORMATION LA English DT Article AB As part of the National Information Infrastructure, the U.S. federal government is establishing a Government Information Locator Service (GILS). GILS will identify and describe public information resources throughout the federal government and provide assistance in obtaining the information. It will be decentralized and will supplement other agency and commercial information dissemination mechanisms. The public will use GILS directly or through intermediaries, including the Government Printing Office and the National Technical Information Service, as well as federal depository libraries, other public libraries, and private sector information services. Direct users will have access to a GILS Core accessible on the Internet without charge. Intermediate access may include kiosks, 800 numbers, electronic mail, bulletin boards, FAX, and offline media such as floppy disks, CD-ROM, and printed works. GILS will use network technology and the American National Standards Institute Z39.50 standard for information search and retrieval so that information can be retrieved in a variety of ways. Direct users may have access to many other major federal and nonfederal information resources, linkages to data systems, and electronic delivery of information products. An Office of Management and Budget Bulletin in 1994 will provide implementing guidance to agencies. The National Institute of Standards and Technology will also establish a Federal Information Processing Standard specifying a GILS Profile and its application for agencies establishing information locators. RP CHRISTIAN, EJ (reprint author), US GEOL SURVEY,DIV INFORMAT SYST,802 NATL CTR,RESTON,VA 22092, USA. NR 7 TC 7 Z9 7 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-0237 J9 J GOV INFORM JI J. Gov. Inf. PD JUL-AUG PY 1994 VL 21 IS 4 BP 305 EP 314 DI 10.1016/1352-0237(94)90055-8 PG 10 WC Information Science & Library Science SC Information Science & Library Science GA NX867 UT WOS:A1994NX86700003 ER PT J AU TUCKER, AB FELDMANN, RM POWELL, CL AF TUCKER, AB FELDMANN, RM POWELL, CL TI SPEOCARCINUS-BERGLUNDI N-SP (DECAPODA, BRACHYURA), A NEW CRAB FROM THE IMPERIAL FORMATION (LATE MIOCENE LATE PLIOCENE) OF SOUTHERN CALIFORNIA SO JOURNAL OF PALEONTOLOGY LA English DT Article ID GULF AB Speocarcinus berglundi n. sp. is described from the Imperial Formation in Riverside County, California. Although the Imperial Formation spans late Miocene through late Pliocene time, the part of the unit that bears crabs has been radiometrically dated as late Miocene. The identification of a new species was based upon comparison with four extant species and represents the first documented fossil occurrence for the genus. The occurrence of this new species suggests that the genus may have originated in the Pacific and, during the Miocene, dispersed through the Isthmus of Panama to the Caribbean. Two of the specimens exhibit parasitism by Bopyridae (Isopoda). C1 US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,MENLO PK,CA 94025. RP TUCKER, AB (reprint author), KENT STATE UNIV,DEPT GEOL,KENT,OH 44242, USA. NR 37 TC 10 Z9 11 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JUL PY 1994 VL 68 IS 4 BP 800 EP 807 PG 8 WC Paleontology SC Paleontology GA PA013 UT WOS:A1994PA01300014 ER PT J AU SPOTL, C HOUSEKNECHT, DW LONGSTAFFE, FJ AF SPOTL, C HOUSEKNECHT, DW LONGSTAFFE, FJ TI AUTHIGENIC CHLORITES IN SANDSTONES AS INDICATORS OF HIGH-TEMPERATURE DIAGENESIS, ARKOMA FORELAND BASIN, USA SO JOURNAL OF SEDIMENTARY RESEARCH SECTION A-SEDIMENTARY PETROLOGY AND PROCESSES LA English DT Article ID X-RAY-DIFFRACTION; ARGILLACEOUS SEDIMENTS; VITRINITE REFLECTANCE; OFFSHORE NORWAY; CLAY-MINERALS; GULF-COAST; ROCKS; POROSITY; ILLITE; VALLEY AB Abundant authigenic chamosite associated with higher-than-average porosities is present in a deep gas reservoir (Spiro sandstone) of the Arkoma Basin, east-central Oklahoma. Three types of chlorite can be distinguished petrographically, all of which appear texturally to have formed early: chlorite peloids, diffuse matrix, and grain coatings. X-ray diffraction, scanning electron microscopy, and electron microprobe studies show that most chlorites are composed of two distinct polytypes, Ib (beta = 90-degrees) and IIb. A third structure, Ia polytype, was identified in only one sample. The relative percentage of the high-temperature IIb structure increases gradually with increasing thermal maturity, from less-than-or-equal-to 10% at 2.0% R(o) up to greater-than-or-equal-to 40% at 3.5% R(o). IIb chlorite forms rather thick, blocky crystals distinct from the thin, pseudohexagonal plates typical of low-temperature Ib chlorite. Temperature estimates based on data on vitrinite reflectance and fluid inclusions suggest that IIb chlorite formed at burial temperatures greater-than-or-equal-to 150-180-degrees-C. Higher contents of tetrahedral Al3+ and slightly higher Fe/[Fe+Mg] ratios in IIb chlorite are consistent with precipitation temperatures higher than those of the Ib structure. A higher-temperature origin for the IIb structure is also consistent with oxygen isotope data. C1 US GEOL SURVEY, RESTON, VA 22092 USA. UNIV WESTERN ONTARIO, DEPT EARTH SCI, LONDON N6A 5B7, ONTARIO, CANADA. RI Longstaffe, Fred/A-6843-2008 NR 77 TC 21 Z9 23 U1 0 U2 3 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 6128 EAST 38TH ST, STE 308, TULSA, OK 74135-5814 USA SN 1073-130X J9 J SEDIMENT RES A JI J. Sediment. Res. Sect. A-Sediment. Petrol. Process. PD JUL 1 PY 1994 VL 64 IS 3 BP 553 EP 566 PG 14 WC Geology SC Geology GA PA956 UT WOS:A1994PA95600011 ER PT J AU HILL, D GASPARINI, P MCNUTT, S RYMER, H AF HILL, D GASPARINI, P MCNUTT, S RYMER, H TI INTERNAL STRUCTURE OF VOLCANOS AND GEOPHYSICAL PRECURSORS OF ERUPTIONS - SELECTED PAPERS FROM NAPOLI-91 - INTERNATIONAL-CONFERENCE ON ACTIVE VOLCANOS AND RISK MITIGATION (1841-1991, JUBILEE OF THE OSSERVATORIO-VESUVIANO), HELD IN NAPOLI, ITALY, 27 AUGUST 1 SEPTEMBER 1991, SPONSORED BY IAVCEI AND CNR - PREFACE SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Editorial Material C1 OPEN UNIV,DEPT EARTH SCI,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND. UNIV ALASKA,INST GEOPHYS,ALASKA VOLCANO OBSERV,FAIRBANKS,AK 99755. UNIV NAPLES FEDERICO 2,DEPT GEOPHYS & VOLCANOL,I-8013 NAPLES,ITALY. RP HILL, D (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, 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 1994 VL 61 IS 3-4 BP R3 EP R4 DI 10.1016/0377-0273(94)90001-9 PG 2 WC Geosciences, Multidisciplinary SC Geology GA PE233 UT WOS:A1994PE23300001 ER PT J AU DELGIUDICE, GD MECH, LD SEAL, US AF DELGIUDICE, GD MECH, LD SEAL, US TI UNDERNUTRITION AND SERUM AND URINARY UREA NITROGEN OF WHITE-TAILED DEER DURING WINTER SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE CONDITION; MINNESOTA; NUTRITIONAL DEPRIVATION; ODOCOILEUS-VIRGINIANUS; SERUM UREA NITROGEN; TRIIODOTHYRONINE; URINARY UREA NITROGEN; CREATININE; WHITE-TAILED DEER ID MULE DEER; BODY-COMPOSITION; PROTEIN; ENERGY; FAWNS; POPULATIONS; STARVATION; INDICATORS; MINNESOTA; PATTERNS AB Direct, practical means of assessing undernutrition in deer (Odocoileus spp.) and other ungulates during winter are needed in areas of research and management, We examined the relationship between mass loss and serum urea nitrogen (SUN) and urinary urea nitrogen: creatinine (U:C) in captive white-tailed deer (O. virginianus), During 4 February-5 May 1988, we maintained 7 adult white-tailed deer on various feeding regimes to simulate natural nutritional restriction during winter. Mass loss was greater (P = 0.037) in deer (17.0-32.2%) fed restricted amounts of a low protein-low energy diet versus control deer (7.0-17.4%) fed the same diet ad libitum. Serum triiodothyronine (T3) concentrations did not differ (P = 0.191) between groups, but declined (P = 0.001) as nutrition declined. Slopes of percent mass loss-SUN and -urinary U:C relationships were positive (P = 0.008 and 0.055) in 7 and 6 deer, respectively. Mean U:C was directly related (r2 = 0.52, P = 0.040) to mean cumulative mass loss, whereas mean SUN was not (r2 = 0.29, P = 0.125). Data presented support the potential of urinary U:C as an index of winter nutritional condition of white-tailed deer; however, additional research is required to provide a complete understanding of this index's utility under field conditions. C1 US VET AFFAIRS MED CTR,RES SERV,MINNEAPOLIS,MN 55417. UNIV MINNESOTA,DEPT FISHERIES & WILDLIFE,ST PAUL,MN 55108. US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708. RP DELGIUDICE, GD (reprint author), MINNESOTA DEPT NAT RESOURCES,FOREST WILDLIFE POPULAT & RES GRP,GRAND RAPIDS,MN 55744, USA. NR 36 TC 33 Z9 36 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 1994 VL 58 IS 3 BP 430 EP 436 DI 10.2307/3809313 PG 7 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA NW893 UT WOS:A1994NW89300006 ER PT J AU SAUER, JR DOLTON, DD DROEGE, S AF SAUER, JR DOLTON, DD DROEGE, S TI MOURNING DOVE POPULATION TREND ESTIMATES FROM CALL-COUNT AND NORTH-AMERICAN BREEDING BIRD SURVEYS SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE BREEDING BIRD SURVEY; CALL-COUNT SURVEY; MOURNING DOVE; POPULATION TRENDS; STATISTICAL METHODS; ZENAIDA-MACROURA ID RELIABILITY AB The mourning dove (Zenaida macroura) Call-count Survey and the North American Breeding Bird Survey provide information on population trends of mourning doves throughout the continental United States. Because surveys are an integral part of the development of hunting regulations, a need exists to determine which survey provides precise information. We estimated population trends from 1966 to 1988 by state and dove management unit, and assessed the relative efficiency of each survey. Estimates of population trend differ (P < 0.05) between surveys in 11 of 48 states; 9 of 11 states with divergent results occur in the Eastern Management Unit. Differences were probably a consequence of smaller sample sizes in the Call-count Survey. The Breeding Bird Survey generally provided trend estimates with smaller variances than did the Call-count Survey. Although the Call-count Survey probably provides more within-route accuracy because of survey methods and timing, the Breeding Bird Survey has a larger sample size of survey routes and greater consistency of coverage in the Eastern Unit. RP SAUER, JR (reprint author), US FISH & WILDLIFE SERV,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708, USA. NR 18 TC 7 Z9 7 U1 0 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 JUL PY 1994 VL 58 IS 3 BP 506 EP 515 DI 10.2307/3809323 PG 10 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA NW893 UT WOS:A1994NW89300016 ER PT J AU ERWIN, RM HATFIELD, JS HOWE, MA KLUGMAN, SS AF ERWIN, RM HATFIELD, JS HOWE, MA KLUGMAN, SS TI WATERBIRD USE OF SALT-MARSH PONDS CREATED FOR OPEN MARSH WATER MANAGEMENT SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE AMERICAN BLACK DUCK; ANAS-RUBRIPES; GULLS; NEW-JERSEY; OPEN MARSH WATER MANAGEMENT; SHOREBIRDS; TERNS; WADING BIRDS; WATERFOWL ID AMERICAN AB Open Marsh Water Management (OMWM) as an alternative to pesticides for mosquito control in saltmarshes along the Atlantic Coast has created debate among biologists. We designed an experiment to determine waterbird (American black duck [Anas rubripes] and other waterfowl, wading birds, shorebirds, gulls, and terns) use (during daylight) of ponds created for mosquito control compared with use of preexisting water bodies (i.e., natural tidal ponds, creeks, old ditches) and refuge impoundments. We also evaluated the influence of pond size and depth on waterbird use of wetlands. We documented bird use of different habitats for 1 year. The highest densities of waterfowl, in autumn, occurred in 0.03-0.06-ha ponds (P < 0.05) versus ponds either <0.02 ha or >0.08 ha; highest shorebird densities occurred in summer in ponds >0.10 ha (P < 0.05). Pond depth affected shorebird and other waterfowl use in some seasons. Comparisons of mean number of birds using created (OMWM) ponds with mean number of birds using other water bodies revealed that most species showed no pattern (P > 0.05) of disproportionate use versus availability. At high tidal levels, most species groups used OMWM ponds in the marsh more often (P < 0.05) than other water bodies. Black ducks and other waterfowl used nearby refuge impoundments in higher densities than they did OMWM ponds, for nesting and during autumn-winter (all Ps < 0.05). Creating small (<0.1 ha) ponds for mosquito control does not enhance waterbird habitat, at least not where large impoundments are in close proximity. We recommend that in areas where OMWM practices seem appropriate, fewer large (>0.10 ha) ponds be constructed with shallow (<15 cm) basins and sloping sides. C1 US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,WASHINGTON,DC 20204. RP ERWIN, RM (reprint author), NATL BIOL SURVEY,PATUXENT WILDLIFE RES CTR,LAUREL,MD 20708, USA. NR 25 TC 24 Z9 25 U1 2 U2 10 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 1994 VL 58 IS 3 BP 516 EP 524 DI 10.2307/3809324 PG 9 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA NW893 UT WOS:A1994NW89300017 ER PT J AU SMITH, GW REYNOLDS, RE AF SMITH, GW REYNOLDS, RE TI HUNTING AND MALLARD SURVIVAL - A REPLY SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Note DE ANAS-PLATYRHYNCHOS; DENSITY DEPENDENCE; HARVEST; HUNTING; MALLARD; SURVIVAL; ULTRASTRUCTURAL MODEL AB Sedinger and Rexstad (1994) objected to the model selection procedures in our analysis of mallard (Anas platyrhynchos) survival (Smith and Reynolds 1992), especially in our analysis of the additive and compensatory nature of hunting mortality. Sedinger and Rexstad (1994) disagreed with pooling data over age-sex classes and the averaging over banding reference areas that was part of our ultrastructural analysis. We believe these objections are unfounded and are based on a misinterpretation of the principle of parsimony. Sedinger and Rexstad (1994) proposed the addition of a density-dependent term to the ultrastructural model to explain observed changes in survival patterns. Their analysis suggested, as we also believe, that density dependence may be a viable alternative. Certainly density-dependent mortality should be investigated further using appropriate mechanistic models. However, a comparison of the 2 models indicates that the hunting hypothesis fits historical data better, and therefore is the more appropriate model. We disagree with Sedinger and Rexstad's (1994) call for implementing differing management actions in the absence of supporting information. C1 US FISH & WILDLIFE SERV,BISMARCK,ND 58501. RP SMITH, GW (reprint author), US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,11500 AMER HOLLY DR,LAUREL,MD 20708, USA. NR 9 TC 13 Z9 13 U1 0 U2 0 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 1994 VL 58 IS 3 BP 578 EP 581 DI 10.2307/3809332 PG 4 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA NW893 UT WOS:A1994NW89300025 ER PT J AU NURNBERG, D WOLLENBURG, I DETHLEFF, D EICKEN, H KASSENS, H LETZIG, T REIMNITZ, E THIEDE, J AF NURNBERG, D WOLLENBURG, I DETHLEFF, D EICKEN, H KASSENS, H LETZIG, T REIMNITZ, E THIEDE, J TI SEDIMENTS IN ARCTIC SEA-ICE - IMPLICATIONS FOR ENTRAINMENT, TRANSPORT AND RELEASE SO MARINE GEOLOGY LA English DT Article; Proceedings Paper CT 4th International Conference on Paleoceanography (ICP IV) CY SEP 21-25, 1992 CL KIEL, GERMANY ID FINE-GRAINED SEDIMENT; OCEANS; SLUSH AB Despite the Arctic sea ice cover's recognized sensitivity to environmental change, the role of sediment inclusions in lowering ice albedo and affecting ice ablation is poorly understood. Sea ice sediment inclusions were studied in the central Arctic Ocean during the Arctic 91 expedition and in the Laptev Sea (East Siberian Arctic Region Expedition 1992). Results from these investigations are here combined with previous studies performed in major areas of ice ablation and the southern central Arctic Ocean. This study documents the regional distribution and composition of particle-laden ice, investigates and evaluates processes by which sediment is incorporated into the ice cover, and identifies transport paths and probable depositional centers for the released sediment. In April 1992, sea ice in the Laptev Sea was relatively clean. The sediment occasionally observed was distributed diffusely over the entire ice column, forming turbid ice. Observations indicate that frazil and anchor ice formation occurring in a large coastal polynya provide a main mechanism for sediment entrainment. In the central Arctic Ocean sediments are concentrated in layers within or at the surface of ice floes due to melting and refreezing processes. The surface sediment accumulation in central Arctic multi-year sea ice exceeds by far the amounts observed in first-year ice from the Laptev Sea in April 1992. Sea ice sediments are generally fine grained, although coarse sediments and stones up to 5 cm in diameter are observed. Component analysis indicates that quartz and clay minerals are the main terrigenous sediment particles. The biogenous components, namely shells of pelecypods and benthic foraminiferal tests, point to a shallow, benthic, marine source area. Apparently, sediment inclusions were resuspended from shelf areas before and incorporated into the sea ice by suspension freezing. Clay mineralogy of ice-rafted sediments provides information on potential source areas. A smectite maximum in sea ice sediment samples repeatedly occurred between 81 degrees N and 83 degrees N along the Arctic 91 transect, indicating a rather stable and narrow smectite rich ice drift stream of the Transpolar Drift. The smectite concentrations are comparable to those found in both Laptev Sea shelf sediments and anchor ice sediments, pointing to this sea as a potential source area for sea ice sediments. In the central Arctic Ocean sea ice clay mineralogy is significantly different from deep-sea clay mineral distribution patterns. The contribution of sea ice sediments to the deep sea is apparently diluted by sedimentary material provided by other transport mechanisms. C1 GEOMAR,MARINE GEOSCI RES CTR,D-24148 KIEL,GERMANY. US GEOL SURVEY,MENLO PK,CA 94025. ENERGIESYST NORD GMBH,D-24103 KIEL,GERMANY. RP NURNBERG, D (reprint author), ALFRED WEGENER INST POLAR & MARINE RES,COLUMBUSSTR,D-27515 BREMERHAVEN,GERMANY. RI Thiede, Jorn/J-5313-2013; Eicken, Hajo/M-6901-2016 OI Thiede, Jorn/0000-0002-3452-2208; NR 89 TC 192 Z9 196 U1 5 U2 37 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 1994 VL 119 IS 3-4 BP 185 EP 214 DI 10.1016/0025-3227(94)90181-3 PG 30 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA PC281 UT WOS:A1994PC28100002 ER PT J AU REIMNITZ, E DETHLEFF, D NURNBERG, D AF REIMNITZ, E DETHLEFF, D NURNBERG, D TI CONTRASTS IN ARCTIC SHELF SEA-ICE REGIMES AND SOME IMPLICATIONS - BEAUFORT SEA VERSUS LAPTEV SEA SO MARINE GEOLOGY LA English DT Article; Proceedings Paper CT 4th International Conference on Paleoceanography (ICP IV) CY SEP 21-25, 1992 CL KIEL, GERMANY ID CONTINENTAL-SHELF; ANCHOR ICE; SEDIMENT; FRAZIL; PARTICLES; POLYNYAS; ALASKA AB The winter ice-regime of the < 80 km wide Alaskan Beaufort Sea shelf is characterized by compression and shearing, resulting in the formation of major grounded pressure ridge systems stabilizing the fast ice on the mid-shelf, and essentially no open-water areas. In contrast, the winter ice-regime of the 500-km wide Laptev Sea shelf is controlled by winds blowing from land to sea, and is therefore dilational. A perennial polynya borders the hundreds of kilometers-wide and very smooth fast ice offshore. In this body of open water, rapidly forming ice is continuously advected offshore by the mean wind field, making the Laptev Sea the single major ice factory for the Arctic Ocean and Transpolar Drift. Conversely, with summer warming this dark polynya turns into an area of high heat gain, which results in the retreat of the ice edge to a much higher latitude and greater distance (>500 km) from the mainland than in the Beaufort Sea. As a result, the annual freeze-up does not incorporate old, deep-draft ice, and with a lack of compression, such deep-draft ice is not generated in situ, as on the Beaufort Sea shelf. The Laptev Sea has as much as 1000 km of fetch at the end of summer, when freezing storms move in and large (6 m) waves can form. Also, for the first three winter months, the polynya lies inshore at a water depth of only 10 m. Turbulence and freezing are excellent conditions for sediment entrainment by fraziI and anchor ice, when compared to conditions in the short-fetched Beaufort Sea. We expect entrainment to occur yearly. Different from the intensely ice-gouged Beaufort Sea shelf, hydraulic bedforms probably dominate in the Laptev Sea. Corresponding with the large volume of ice produced, more dense water is generated in the Laptev Sea, possibly accompanied by downslope sediment transport. Thermohaline convection at the midshelf polynya, together with the reduced rate of bottom disruption by ice keels, may enhance benthic productivity and permit establishment of open shelf benthic communities which in the Beaufort Sea can thrive only in the protection of barrier islands. Indirect evidence for high benthic productivity is found in the presence of walrus, who also require year-round open water. By contrast, lack of a suitable environment restricts walrus from the Beaufort Sea, although over 700 km farther to the south. We could speculate on other consequences of the different ice regimes in the Beaufort and Laptev Seas, but these few examples serve to point out the dangers of exptrapolating from knowledge gained in the North American Arctic to other shallow Arctic shelf settings. C1 GEOMAR,MARINE GEOSCI RES CTR,D-24148 KIEL,GERMANY. ALFRED WEGENER INST POLAR & MEEREFORSCH,D-27515 BREMERHAVEN,GERMANY. RP REIMNITZ, E (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 34 TC 85 Z9 90 U1 2 U2 14 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 1994 VL 119 IS 3-4 BP 215 EP 225 DI 10.1016/0025-3227(94)90182-1 PG 11 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA PC281 UT WOS:A1994PC28100003 ER PT J AU CRONIN, TM HOLTZ, TR WHATLEY, RC AF CRONIN, TM HOLTZ, TR WHATLEY, RC TI QUATERNARY PALEOCEANOGRAPHY OF THE DEEP ARCTIC-OCEAN BASED ON QUANTITATIVE-ANALYSIS OF OSTRACODA SO MARINE GEOLOGY LA English DT Article ID RAPID SEDIMENTATION; NORTH-ATLANTIC; WATER-MASSES; CIRCULATION; BASIN; SEAS; STRATIGRAPHY; GREENLAND; SLOPE AB Ostracodes were studied from deep Arctic Ocean cores obtained during the Arctic 91 expedition of the Polarstern to the Nansen, Amundsen and Makarov Basins, the Lomonosov Ridge, Morris Jesup Rise and Yermak Plateau, in order to investigate their distribution in Arctic Ocean deep water (AODW) and apply these data to paleoceanographic reconstruction of bottom water masses during the Quaternary. Analyses of coretop assemblages from Arctic 91 boxcores indicate the following: ostracodes are common at all depths between 1000 and 4500 m, and species distribution is strongly influenced by water mass characteristics and bathymetry; quantitative analyses comparing Eurasian and Canada Basin assemblages indicate that distinct assemblages inhabit regions east and west of the Lomonosov Ridge, a barrier especially important to species living in lower AODW; deep Eurasian Basin assemblages are more similar to those living in Greenland Sea deep water (GSDW) than those in Canada Basin deep water; two upper AODW assemblages were recognized throughout the Arctic Ocean, one living between 1000 and 1500 m, and the other, having high species diversity, at 1500-3000 m. Downcore quantitative analyses of species' abundances and the squared chord distance coefficient of similarity reveals a distinct series of abundance peaks in key indicator taxa interpreted to signify the following late Quaternary deep water history of the Eurasian Basin. During the Last Glacial Maximum (LGM), a GSDW/AODW assemblage, characteristic of cold, well oxygenated deep water >3000 m today, inhabited the Lomonosov Ridge to depths as shallow as 1000 m, perhaps indicating the influence of GSDW at mid-depths in the central Arctic Ocean. During Termination 1, a period of high organic productivity associated with a strong inflowing warm North Atlantic layer occurred. During the mid-Holocene, several key faunal events indicate a period of warming and/or enhanced flow between the Canada and Eurasian Basins. A long-term record of ostracode assemblages from kastenlot core PS2200-5 (1073 m water depth) from the Morris Jesup Rise indicates a quasi-cyclic pattern of water mass changes during the last 300 kpr. Interglacial ostracode assemblages corresponding to oxygen isotope stages 1, 5, and 7 indicate rapid changes in dissolved oxygen and productivity during glacial-interglacial transitions. C1 UNIV COLL WALES, INST EARTH STUDIES, ABERYSTWYTH SY23 3DB, DYFED, WALES. RP CRONIN, TM (reprint author), US GEOL SURVEY, MAIL STOP 970 NATL CTR, RESTON, VA 22092 USA. NR 53 TC 47 Z9 50 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 EI 1872-6151 J9 MAR GEOL JI Mar. Geol. PD JUL PY 1994 VL 119 IS 3-4 BP 305 EP 332 DI 10.1016/0025-3227(94)90188-0 PG 28 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA PC281 UT WOS:A1994PC28100009 ER PT J AU HAMPTON, MA AF HAMPTON, MA TI CLASSIFICATION PROPERTIES OF HOLOCENE SEDIMENT IN SHELIKOF STRAIT, ALASKA SO MARINE GEORESOURCES & GEOTECHNOLOGY LA English DT Article DE CLASSIFICATION PROPERTIES; GEOTECHNICAL PROPERTIES; SEDIMENT PROPERTIES; SHELIKOF STRAIT ID GEOTECHNICAL PROPERTIES AB Sediment in Shelikof Strait, which is located between the Kodiak island group and the Alaska Peninsula, varies continuously from muddy sand at the proximal northeast end to silty clay at the distal southwest end. A textural sorting pattern is evident, with pronounced and regular changes in sand content throughout the strait but with consistent separation of silt from clay only at the lowest sand contents. Using data from 74 samples, a strong predictor equation for plasticity index is derived from the amount of clay-size grains (< 4 mu m, geological definition) and grain specific gravity. Vane shear strength values fall in the very soft to medium range. They are best predicted by the amount of silt-size grains (an indicator of mean grain size); the overburden stress at the shallow sampling depths influences the strength values only slightly. For regressions of plasticity index and vane strength, predictor equations similar to those derived from the total data set can be obtained using as few as 17 samples if the range of the predictor variables is approximately maintained. RP HAMPTON, MA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 999,MENLO PK,CA 94025, USA. NR 36 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1064-119X J9 MAR GEORESOUR GEOTEC JI Mar. Geores. Geotechnol. PD JUL-SEP PY 1994 VL 12 IS 3 BP 237 EP 257 PG 21 WC Engineering, Ocean; Engineering, Geological; Oceanography; Mining & Mineral Processing SC Engineering; Oceanography; Mining & Mineral Processing GA QV618 UT WOS:A1994QV61800003 ER PT J AU PEREIRA, WE HOSTETTLER, FD CASHMAN, JR NISHIOKA, RS AF PEREIRA, WE HOSTETTLER, FD CASHMAN, JR NISHIOKA, RS TI OCCURRENCE AND DISTRIBUTION OF ORGANOCHLORINE COMPOUNDS IN SEDIMENT AND LIVERS OF STRIPED BASS (MORONE-SAXATILIS) FROM THE SAN-FRANCISCO BAY DELTA ESTUARY SO MARINE POLLUTION BULLETIN LA English DT Article ID POLYCHLORINATED-BIPHENYLS; DIE-OFF; CALIFORNIA; RESIDUES AB A preliminary assessment was made in 1992 of chlorinated organic compounds in sediments and in livers of striped bass from the San Franciso Bay-Delta Estuary. Samples of sediment and striped bass livers contained DDT (ethane, 1,1,1-trichloro-2,2-bis (p-chlorophenyl)-) and its degradation products, DDD (ethane, 1,1-dichloro-2,2-bis(p-chlorophenyl)-) and DDE (ethylene, 1,1-dichloro-2,2-bis (p-chlorophenyl)-); PCBs (poly-chlorinated biphenyls); alpha and gamma chlordane, and cis and trans nonachlor. In addition, the livers of striped bass contained small concentrations of DCPA (dimethyl tetrachloroterephthalate), a pre-emergent herbicide. Agricultural run-off from the Sacramento and San Joaquin Rivers, as well as atmospheric deposition, are probably responsible for a low chronic background of DDT in sediments throughout San Francisco Bay. Larger concentrations of DDT in sediment near Richmond in the Central Bay, and Coyote Creek in the South Bay may be derived from point sources. Ratios of pentachloro isomers of PCBs to hexachloro isomers in the South Bay sediments were different from those in the Central and North Bay, suggesting either differences in microbial activity in the sediments or different source inputs of PCBs. Concentrations of alpha chlordane in livers of striped bass were greater than those of gamma chlordane, which suggests a greater environmental stability and persistence of alpha chlordane. Trans nonachlor, a minor component of technical chlordane, was present in greater concentrations than alpha and gamma chlordane and cis nonachlor. Trans nonachlor is more resistant to metabolism than alpha and gamma chlordane and cis nonachlor, and serves as an environmentally stable marker compound of chlordane contamination in the estuary. Chlorinated organic compounds have bioaccumulated in the livers of striped bass. These compounds may contribute to the decline of the striped bass in San Francisco Bay-Delta Estuary. C1 IGEN, RES INST, SEATTLE, WA 98109 USA. UNIV CALIF BERKELEY, DEPT INTEGRAT BIOL, CANC RES LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, BODEGA MARINE LAB, BERKELEY, CA 94720 USA. RP US GEOL SURVEY, MENLO PK, CA 94025 USA. NR 31 TC 23 Z9 23 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD JUL PY 1994 VL 28 IS 7 BP 434 EP 441 DI 10.1016/0025-326X(94)90129-5 PG 8 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA PC745 UT WOS:A1994PC74500009 ER PT J AU MILES, AK HILLS, S AF MILES, AK HILLS, S TI METALS IN DIET OF BERING SEA WALRUS - MYA-SP AS A POSSIBLE TRANSMITTER OF ELEVATED CADMIUM AND OTHER METALS SO MARINE POLLUTION BULLETIN LA English DT Note ID HEAVY-METALS; ALASKA C1 US FISH & WILDLIFE SERV, ALASKA FISH & WILDLIFE RES CTR, FAIRBANKS, AK 99701 USA. RP UNIV CALIF DAVIS, DEPT WILDLIFE & FISHERIES BIOL, PATUXENT WILDLIFE RES CTR, DAVIS, CA 95616 USA. NR 20 TC 8 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD JUL PY 1994 VL 28 IS 7 BP 456 EP 458 DI 10.1016/0025-326X(94)90133-3 PG 3 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA PC745 UT WOS:A1994PC74500013 ER PT J AU KRISE, WF MEADE, JW MCCLAIN, JR AF KRISE, WF MEADE, JW MCCLAIN, JR TI EVALUATION OF THE EFFECTS OF AN OXYGEN INJECTION SYSTEM ON THE GROWTH, HEMATOLOGY, AND IMMUNITY OF LAKE TROUT SO PROGRESSIVE FISH-CULTURIST LA English DT Note ID GAS SUPERSATURATION AB Fingerling lake trout (Salvelinus namaycush) were reared for 64 d at three pressures of dissolved gases, expressed in relation to saturation values (DELTAP)-untreated (control) water, DELTAP = 10 mm Hg; water treated by column degassing with air, DELTAP = 9 mm Hg; and water treated with an oxygen injection system, DELTAP = -20 mm Hg. Dissolved oxygen concentration for experimental groups was increased with column degassing by 7.8% and with oxygen injection by 8.7%. Nitrogen level was reduced 2.2% with columns receiving air and 7.4% with the oxygen injection system. There were no differences in production, mean lengths, or mean weights among fish reared in the three treatments. Hematocrit, plasma protein levels, and mean antibody microtiters to injected Salmonella H antigen were not different among fish from the three water treatments. C1 US FISH & WILDLIFE SERV,IRON RIVER NATL FISH HATCHERY,IRON RIVER,WI 54847. RP KRISE, WF (reprint author), US FISH & WILDLIFE SERV,NATL FISHERY RES & DEV LAB,RURAL DELIVERY 4,BOX 63,WELLSBORO,PA 16901, USA. NR 12 TC 1 Z9 1 U1 0 U2 0 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 JUL PY 1994 VL 56 IS 3 BP 207 EP 210 DI 10.1577/1548-8640(1994)056<0207:EOTEOA>2.3.CO;2 PG 4 WC Fisheries SC Fisheries GA NZ350 UT WOS:A1994NZ35000010 ER PT J AU RAMOS, KT FRIES, LT BERKHOUSE, CS FRIES, JN AF RAMOS, KT FRIES, LT BERKHOUSE, CS FRIES, JN TI APPARENT SUNBURN OF JUVENILE PADDLEFISH SO PROGRESSIVE FISH-CULTURIST LA English DT Note ID SOLAR ULTRAVIOLET-RADIATION AB Juvenile paddlefish (Polyodon spathula) transferred to outdoor raceways at the National Fish Hatchery and Technology Center, San Marcos, Texas, exhibited dorsal skin lesions characteristic of sunburn within 1 week. These fish were assigned to one of three classifications: normal, burned, or curved (curved rostrum), depending upon the severity of the lesions. Approximately equal numbers of fish from each classification were stocked into a raceway in two compartments. One section remained uncovered and received full sunlight while the other was covered and received reduced sunlight for 51 d. Survival of the covered and uncovered fish was 87% and 55%, respectively. Many of the covered fish returned to the normal condition. C1 US FISH & WILDLIFE SERV,SAN MARCOS NATL FISH HATCHERY & TECHNOL CTR,SAN MARCOS,TX 78666. RP RAMOS, KT (reprint author), TEXAS PARKS & WILDLIFE DEPT,AE WOOD STATE FISH HATCHERY,SAN MARCOS,TX 78667, USA. NR 16 TC 12 Z9 14 U1 0 U2 2 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 JUL PY 1994 VL 56 IS 3 BP 214 EP 216 DI 10.1577/1548-8640(1994)056<0214:ASOJP>2.3.CO;2 PG 3 WC Fisheries SC Fisheries GA NZ350 UT WOS:A1994NZ35000012 ER PT J AU PENDALL, EG HARDEN, JW TRUBMORE, SE CHADWICK, OA AF PENDALL, EG HARDEN, JW TRUBMORE, SE CHADWICK, OA TI ISOTOPIC APPROACH TO SOIL CARBONATE DYNAMICS AND IMPLICATIONS FOR PALEOCLIMATIC INTERPRETATIONS SO QUATERNARY RESEARCH LA English DT Article ID PEDOGENIC CARBONATE; MOJAVE-DESERT; ARID-ZONE; PALEOSOLS; CALICHE; MODEL; CHEMISTRY; PAKISTAN; NEVADA; OXYGEN AB The radiocarbon content and stable isotope composition of soil carbonate are best described by a dynamic system in which isotopic reequilibration occurs as a result of recurrent dissolution and reprecipitation. Depth of water penetration into the soil profile, as well as soil age, determines the degree of carbonate isotope reequilibration. We measured deltaC-13, deltaO-18, and radiocarbon content of gravel rinds and fine (<2 mm) carbonate in soils of 3 different ages (1000, 3800, and 6300 C-14 yr B.P.) to assess the degree to which they record and preserve a climatic signal. In soils developing in deposits independently dated at 3800 and 6300 radiocarbon yr B.P., carbonate radiocarbon content above 40 cm depth suggests continual dissolution and reprecipitation, presumably due to frequent wetting events. Between 40 and 90 cm depth, fine carbonate is dissolved and precipitated as rinds that are not redissolved subsequently. Below 90 cm depth in these soils, radiocarbon content indicates that inherited, fine carbonate undergoes little dissolution and reprecipitation. In the 3800- and 6300-yr-old soils, deltaC-13 in rind and fine carbonate follows a decreasing trend with depth, apparently in equilibrium with modem soil gas, as predicted by a diffusive model for soil CO2. DeltaO-18 also decreases with depth due to greater evaporative enrichment above 50 cm depth. In contrast, carbonate isotopes in a 1000-yr-old deposit do not reflect modern conditions even in surficial horizons; this soil has not undergone significant pedogenesis. There appears to be a lag of at least 1000 but less than 3800 yr before carbonate inherited with parent material is modified by ambient climatic conditions. Although small amounts of carbonate are inherited with the parent material, the rate of pedogenic carbonate accumulation indicates that Ca is derived primarily from eolian and rainfall sources. A model describing carbonate input and radiocarbon decay suggests that fine carbonate below 90 cm is mostly detrital (inherited) and that carbonate rinds have been forming pedogenically at a constant rate since alluvial fans were deposited. (C) 1994 University of Washington. C1 US GEOL SURVEY,MENLO PK,CA 94025. UNIV CALIF IRVINE,DEPT GEOSCI,IRVINE,CA 92717. JET PROP LAB,PASADENA,CA 91109. OI Pendall, Elise/0000-0002-1651-8969 NR 41 TC 52 Z9 58 U1 1 U2 14 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JUL PY 1994 VL 42 IS 1 BP 60 EP 71 DI 10.1006/qres.1994.1054 PG 12 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PB179 UT WOS:A1994PB17900006 ER PT J AU MUHS, DR KENNEDY, GL ROCKWELL, TK AF MUHS, DR KENNEDY, GL ROCKWELL, TK TI URANIUM-SERIES AGES OF MARINE TERRACE CORALS FROM THE PACIFIC COAST OF NORTH-AMERICA AND IMPLICATIONS FOR LAST-INTERGLACIAL SEA-LEVEL HISTORY SO QUATERNARY RESEARCH LA English DT Article ID SAN-CLEMENTE ISLAND; U-SERIES; MASS-SPECTROMETRY; SOUTH-PACIFIC; NEW-GUINEA; CALIFORNIA; REEFS; CHRONOLOGY; PERIOD; UPLIFT AB Few of the marine terraces along the Pacific coast of North America have been dated using uranium-series techniques. Ten terrace sequences from southern Oregon to southern Baja California Sur have yielded fossil corals in quantities suitable for U-series dating by alpha spectrometry. U-series-dated terraces representing the approximately 80,000 yr sea-level high stand are identified in five areas (Bandon, Oregon; Point Arena, San Nicolas Island, and Point Loma, California; and Punta Banda, Baja California); terraces representing the approximately 125,000 yr sea-level high stand are identified in eight areas (Cayucos, San Luis Obispo Bay, San Nicolas Island, San Clemente Island, and Point Loma, California; Punta Banda and Isla Guadalupe, Baja California; and Cabo Pulmo, Baja California Sur). On San Nicolas Island, Point Loma, and Punta Banda, both the approximately 80,000 and the approximately 125,000 yr terraces are dated. Terraces that may represent the approximately 105,000 sea-level high stand are rarely preserved and none has yielded corals for U-series dating. Similarity of coral ages from midlatitude, erosional marine terraces with coral ages from emergent, constructional reefs on tropical coastlines suggests a common forcing mechanism, namely glacioeustatically controlled fluctuations in sea level superimposed on steady tectonic uplift. The low marine terrace dated at approximately 125,000 yr on Isla Guadalupe, Baja California, presumed to be tectonically stable, supports evidence from other localities for a +6-m sea level at that time. Data from the Pacific Coast and a compilation of data from other coasts indicate that sea levels at approximately 80,000 and approximately 105,000 yr may have been closer to present sea level (within a few meters) than previous studies have suggested. (C) 1994 University of Washington. C1 SAN DIEGO STATE UNIV,DEPT GEOL SCI,SAN DIEGO,CA 92182. RP MUHS, DR (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 974,BOX 25046,DENVER,CO 80225, USA. OI Rockwell, Thomas/0000-0001-5319-6447 NR 66 TC 51 Z9 52 U1 0 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JUL PY 1994 VL 42 IS 1 BP 72 EP 87 DI 10.1006/qres.1994.1055 PG 16 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA PB179 UT WOS:A1994PB17900007 ER PT J AU FREDERIKSEN, NO AF FREDERIKSEN, NO TI PALEOCENE FLORAL DIVERSITIES AND TURNOVER EVENTS IN EASTERN NORTH-AMERICA AND THEIR RELATION TO DIVERSITY MODELS SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Article; Proceedings Paper CT Symposium on Palaeofloristic and Palaeoclimatic Changes in Cretaceous and Tertiary Times, at the 8th International Palynological Congress CY SEP, 1992 CL AIX EN PROVENCE, FRANCE ID CRETACEOUS-TERTIARY BOUNDARY; EOCENE BOUNDARY; FOSSIL RECORD; POLLEN; MACROEVOLUTION; EXTINCTIONS; EVOLUTION; PROGRESS; HISTORY; PLANTS AB This paper uses angiosperm pollen taxon turnover (first and last appearance) and diversity events as metrics to describe the Paleocene floral history of the eastern Gulf Coast; data are from 64 samples and 67 angiosperm pollen taxa. Angiosperm pollen diversity was very low at the beginning of the Paleocene, rose slowly and then somewhat more rapidly to a maximum for the epoch in the middle of the late Paleocene as a result of the maximum in rate of first appearances during the late early Paleocene and earliest late Paleocene. Diversity then dropped very rapidly at or near the end of the epoch as the rate of last appearances reached its maximum, resulting in the Terminal Paleocene Extinction Event. The latest Paleocene diversity decline coincided with an increase in mean annual temperature and probably in rainfall, representing the beginning of the climatic maximum for the Tertiary which characterized the early Eocene. The increase in diversity of early Paleocene floras in the eastern Gulf Coast resulted from exploitation of unfilled ecospace originating from (1) low regional diversity following the Terminal Cretaceous Extinction Event, and (2) creation of many new niches during the Paleocene, resulting, according to megafloral evidence, from a change to a new vegetation type (multistratal tropical rainforest) brought about by an increase in rainfall. The slow rate of recovery of earliest Paleocene angiosperm diversity in the eastern Gulf Coast may be explained in part by the diversity-dependence model of Carr and Kitchell (1980). However, additional factors may have contributed to the slow recovery: (1) the adverse terminal Cretaceous climates may have extended into the early Paleocene, (2) the initial Paleocene environment of the eastern Gulf Coast may have contained relatively few niches, (3) some earliest Paleocene angiosperms, particularly trees, may have had inherently poor capabilities for rapid evolution, and (4) there was a lack of significant immigration of new taxa to the region. In contrast, the earliest Eocene angiosperm flora recovered very rapidly from the Terminal Paleocene Extinction Event, and this high recovery rate resulted to a significant degree from immigration of new taxa from Europe; thus, the shape of the earliest Eocene diversity curve supports the immigration-dependence recovery model of Barry et al. (1991). RP FREDERIKSEN, NO (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 80 TC 17 Z9 19 U1 0 U2 5 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 JUL PY 1994 VL 82 IS 3-4 BP 225 EP 238 DI 10.1016/0034-6667(94)90077-9 PG 14 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA NY946 UT WOS:A1994NY94600003 ER PT J AU LOPEZ, NC AF LOPEZ, NC TI JACKSON-HOLE SYMPOSIUM REVISITED - PRESIDENTS PAGE SO WATER RESOURCES BULLETIN LA English DT Editorial Material RP LOPEZ, NC (reprint author), US GEOL SURVEY,417 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 20170-5531 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD JUL-AUG PY 1994 VL 30 IS 4 BP R3 EP R3 PG 1 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA PG099 UT WOS:A1994PG09900001 ER PT J AU MILLY, PCD AF MILLY, PCD TI CLIMATE, SOIL-WATER STORAGE, AND THE AVERAGE ANNUAL WATER-BALANCE SO WATER RESOURCES RESEARCH LA English DT Article ID SPATIAL VARIABILITY; VEGETATION; DYNAMICS AB This paper describes the development and testing of the hypothesis that the long-term water balance is determined only by the local interaction of fluctuating water supply (precipitation) and demand (potential evapotranspiration), mediated by water storage in the soil. Adoption of this hypothesis, together with idealized representations of relevant input variabilities in time and space, yields a simple model of the water balance of a finite area having a uniform climate. The partitioning of average annual precipitation into evapotranspiration and runoff depends on seven dimensionless numbers: the ratio of average annual potential evapotranspiration to average annual precipitation (index of dryness); the ratio of the spatial average plant-available water-holding capacity of the soil to the annual average precipitation amount; the mean number of precipitation events per year; the shape parameter of the gamma distribution describing spatial variability of storage capacity; and simple measures of the seasonality of mean precipitation intensity, storm arrival rate, and potential evapotranspiration. The hypothesis is tested in an application of the model to the United States east of the Rocky Mountains, with no calibration. Study area averages of runoff and evapotranspiration, based on observations, are 263 mm and 728 mm, respectively; the model yields corresponding estimates of 250 mm and 741 mm, respectively, and explains 88% of the geographical variance of observed runoff within the study region. The differences between modeled and observed runoff can be explained by uncertainties in the model inputs and in the observed runoff. In the humid (index of dryness <1) parts of the study area, the dominant factor producing runoff is the excess of annual precipitation over annual potential evapotranspiration, but runoff caused by variability of supply and demand over time is also significant; in the arid (index of dryness >1) parts, all of the runoff is caused by variability of forcing over time. Contributions to model runoff attributable to small-scale spatial variability of storage capacity are insignificant throughout the study area. The consistency of the model with observational data is supportive of the supply-demand-storage hypothesis, which neglects infiltration excess runoff and other finite-permeability effects on the soil water balance. RP MILLY, PCD (reprint author), NOAA,US GEOL SURVEY,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 33 TC 276 Z9 285 U1 8 U2 79 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 JUL PY 1994 VL 30 IS 7 BP 2143 EP 2156 DI 10.1029/94WR00586 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA NV579 UT WOS:A1994NV57900016 ER PT J AU ANDREWS, ED AF ANDREWS, ED TI MARGINAL BED-LOAD TRANSPORT IN A GRAVEL-BED STREAM, SAGEHEN CREEK, CALIFORNIA SO WATER RESOURCES RESEARCH LA English DT Article ID SIZE DISTRIBUTION; RIVERS; MOTION AB Marginal bed load transport describes the condition when relatively few bed particles are moving at any time. Bed particles resting in the shallowest bed pockets will move when the dimensionless shear stress tau* exceeds a value of about 0.020. As tau* increases, the number of bed particles moving increases. Significant motion of bed particles, i.e., when a substantial fraction of the bed particles are moving, occurs when tau* exceeds a value of about 0.060. Thus marginal bed load transport occurs over the domain 0.020 < tau* < 0.060. Marginal bed load transport rates and associated hydraulic characteristics of Sagehen Creek, a small mountain gravel bed stream, were measured on 55 days at discharges ranging from slightly less than one half of the bank-full discharge to more than 4 times the bank-full discharge. Dimensionless shear stress varied from 0.032 to 0.042, and bed particles as large as the 80th percentile of the bed surface were transported. The relation between reference dimensionless shear stress and relative particle protrusion for Sagehen Creek was determined by varying tau(ri)* to obtain the best fit of the Parker bed load function to the measured transport rates. During the period of record (water years 1954-4991), the mean annual quantity of bed load transported past the Sagehen Creek gage was 24.7 tons. Forty-seven percent of all bed load transported during the 38 years of record occurred in just 6 years. During 10 of the 38 years of record, essentially no bed load was transported. The median diameter of bed load was 26 mm, compared to 58 mm in the surface bed material. RP ANDREWS, ED (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,3215 MARINE ST,BOULDER,CO 80303, USA. NR 23 TC 58 Z9 58 U1 3 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 JUL PY 1994 VL 30 IS 7 BP 2241 EP 2250 DI 10.1029/94WR00553 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA NV579 UT WOS:A1994NV57900024 ER PT J AU TROUTMAN, BM KARLINGER, MR AF TROUTMAN, BM KARLINGER, MR TI INFERENCE FOR A GENERALIZED GIBBSIAN DISTRIBUTION ON CHANNEL NETWORKS SO WATER RESOURCES RESEARCH LA English DT Article ID DRAINAGE NETWORKS; ENERGY AB We introduce a two-parameter (beta0 and beta1) Gibbsian probability model to characterize the spatial behavior of channel networks. This model is defined for trees draining basins on a square lattice. The probability of a tree s is proportional to exp [-beta0H(s, beta1)], where H(s, beta1) is taken to be a summation over lattice points upsilon in the basin of A(upsilon, s)beta1, letting A(upsilon, s) be the area upstream from (but not including) point upsilon. Procedures are developed for estimating the parameters given an actual network obtained, for example, from digital elevation data and for using bootstrapping to obtain confidence intervals for these estimates. We also develop several goodness of fit tests for the model. These procedures are applied to a set of data for 50 subnetworks from Willow Creek in Montana. The estimation algorithm converged successfully for 34 of these subnetworks. For these 34 subnetworks the two-parameter model gives in most cases a fit significantly better than a one-parameter model (with beta1 constrained to be 1) studied in a previous paper. There is still, however, statistically significant lack of fit for as many as 13 subnetworks (depending on which test is applied). The parameter beta1 averages 0.75 for the 34 subnetworks. The function H(s, beta1) in the Gibbsian model may be given a statistical mechanical interpretation of ''energy'' associated with a configuration s. Other researchers have employed a similar definition of energy expenditure in drainage systems but have given physical arguments that the exponent beta1 should be 0.50. We finally discuss the idea of defining ''optimal channel networks'' as those which minimize free energy in the Gibbsian model; it is shown that minimization of energy (rather than free energy) as other researchers have proposed is valid only under the assumption of a ''low temperature'' (i.e., large beta0) system. Our results indicate that this assumption would not be justified for Willow Creek. We devote some discussion to the discrepancies between our approach and results and those of other researchers. RP TROUTMAN, BM (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 418,DENVER,CO 80225, USA. NR 19 TC 10 Z9 10 U1 0 U2 1 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 JUL PY 1994 VL 30 IS 7 BP 2325 EP 2338 DI 10.1029/94WR00765 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA NV579 UT WOS:A1994NV57900030 ER PT J AU VISSCHER, PT CULBERTSON, CW OREMLAND, RS AF VISSCHER, PT CULBERTSON, CW OREMLAND, RS TI DEGRADATION OF TRIFLUOROACETATE IN OXIC AND ANOXIC SEDIMENTS SO NATURE LA English DT Article ID ESTUARINE SEDIMENTS; SULFATE REDUCTION; ORGANIC-COMPOUNDS; METHYL-FLUORIDE; DIMETHYL ETHER; METHANE; OXIDATION; BACTERIUM; HYDROCHLOROFLUOROCARBONS; TRANSFORMATIONS AB THE deleterious effect of chlorofluorocarbons on stratospheric ozone has led to international cooperation to end their use(1-3). The search for acceptable alternatives has focused on hydrofluorocarbons (HFCs) or hydrochlorofluorocarbons (HCFCs) which are attractive because they have relatively short atmospheric residence times(4). HFCs and HCFCs are attacked by tropospheric hydroxyl radicals, leading to the formation of trifluoroacetate (TFA)(5). Most of the atmospheric TFA is deposited at the Earth's surface(6), where it is thought to be highly resistant to bacterial attack(5). Therefore, use of HCFCs and HFCs may lead to accumulation of TFA in soils, where it could prove toxic or inhibitory to plants and soil microbial communities(5,7). Although little is known about the toxicity of TFA, monofluoroacetate, which occurs at low levels in some plants(8) and which is susceptible to slow attack by aerobic soil microbes(9), is known to be acutely toxic(10-13). Here we report that TFA can be rapidly degraded microbially under anoxic and oxic conditions. These results imply that significant microbial sinks exist in nature for the elimination of TFA from the environment. We also show that oxic degradation of TFA leads to the formation of fluoroform, a potential ozone-depleting compound with a much longer atmospheric lifetime than the parent compounds. RP VISSCHER, PT (reprint author), US GEOL SURVEY,MAILSTOP 465,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. OI Visscher, Pieter/0000-0001-6911-1532 NR 35 TC 63 Z9 65 U1 2 U2 10 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUN 30 PY 1994 VL 369 IS 6483 BP 729 EP 731 DI 10.1038/369729a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NU581 UT WOS:A1994NU58100054 ER PT J AU PLESCIA, JB SHOEMAKER, EM SHOEMAKER, CS AF PLESCIA, JB SHOEMAKER, EM SHOEMAKER, CS TI GRAVITY SURVEY OF THE MOUNT-TOONDINA IMPACT STRUCTURE, SOUTH-AUSTRALIA SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID CRATER AB Gravity and seismic reflection data, together with geologic mapping, indicate that the Mount Toondina feature in South Australia is best interpreted as an eroded 4-km-diameter impact structure consisting of a ring structural depression surrounding a pronounced central uplift. Beds at the center of the structure within the central uplift have been raised as much as 200 m from depth and deformed by convergent flow. Seismic reflection data indicate that deformation extends to depths of only almost-equal-to 800 m; at greater depths the reflectors are nearly flat lying, indicating little or no deformation. Gravity data show residual anomalies of +1.0 mGal coincident with the central uplift and a -0.5 Mgal low associated with the ring structural depression. Modeling of the gravity data indicates that relatively high-density material occurs within the central uplift, whereas the ring depression is filled with low-density material. The deformation at Mount Toondina is typical of a complex impact crater; the 4-km diameter is consistent with the expected threshold size for complex craters formed in weak to moderate strength sedimentary rocks. C1 US GEOL SURVEY,ASTROGEOL BRANCH,FLAGSTAFF,AZ 86001. RP PLESCIA, JB (reprint author), JET PROP LAB,DIV EARTH & SPACE SCI,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Plescia, Jeffrey/B-7738-2016 NR 33 TC 5 Z9 5 U1 0 U2 2 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 JUN 25 PY 1994 VL 99 IS E6 BP 13167 EP 13179 DI 10.1029/94JE00660 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NU132 UT WOS:A1994NU13200006 ER PT J AU Smirnov, VV Gillette, DA Golitsyn, GS MacKinnon, DJ AF Smirnov, V. V. Gillette, D. A. Golitsyn, G. S. MacKinnon, D. J. TI The origin and evolution of dust clouds in Central Asia SO ATMOSPHERIC RESEARCH LA English DT Article AB Data from a high resolution radiometer AVHRR (580-680 nm optical lengthwaves) installed on the "NOAA-11" satellite as well as TV (500-700 nm) and IR ( 8000-12000 nm) equipment of the Russia satellite "Meteor-2/16" were used to study the evolution of dust storms for 1-30 September 1989 in Tajikistan, Uzbekistan, Turkmenistan and Afghanistan. These data help to validate the hypothesis, that long-term dusted boundary layer (duration of the order of a day or more), but of comparatively not high optical density (4-10 kin meteorogical visibility range at the 20-50 km background), is formed after the northwest intrusions into a region of intensive cold fronts at the surface wind velocities of 7-15 m/s. Stability of dust clouds of vertical power to 3-3.5 km (up to an inversion level) is explained by an action of collective buoyancy factors at heating the dust particles of 2-4 gm in mean diameter by solar radiation. The more intensive intrusions stimulate a formation of simultaneously dust and water clouds. The last partially reduce the solar radiation (by the calculations of the order of 30-50%) and decrease the role of buoyancy factors. Thus, initiated is the intensive but short-term dusted boundary layer at horizontal visibility of 50-200 m. C1 [Smirnov, V. V.] Fed Hydrometeorol Serv, Inst Expt Meteorol, Obninsk 249020, Russia. [Gillette, D. A.] ARS ARL NOAA, Boulder, CO 80303 USA. [Golitsyn, G. S.] Russia Acad Sci, Inst Atmospher Phys, Moscow, Russia. [MacKinnon, D. J.] US Geol Survey, Flagstaff, AZ 86001 USA. RP Smirnov, VV (reprint author), Fed Hydrometeorol Serv, Inst Expt Meteorol, Obninsk 249020, Russia. NR 13 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD JUN 20 PY 1994 VL 34 IS 1-4 BP 169 EP 176 DI 10.1016/0169-8095(94)90088-4 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA V38LL UT WOS:000209344800011 ER PT J AU SAVAGE, JC LISOWSKI, M AF SAVAGE, JC LISOWSKI, M TI STRAIN ACCUMULATION NORTH OF LOS-ANGELES, CALIFORNIA, AS A FUNCTION OF TIME, 1977-1992 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN-CALIFORNIA AB No significant change in the rate of strain accumulation in a 40 x 120 km trilateration network spanning the San Gabriel mountains was observed from 1977.5 to 1991.8 despite an apparent increase in seismicity (M(L) > 4.5) beginning in late 1987 in the northern Los Angeles basin immediately to the south. The observed deformation (0.13 +/- 0.01 mustrain/yr right-lateral shear across a vertical plane striking N63-degrees-W +/- 1-degrees) can be attributed to strain accumulation on the San Andreas fault (local strike N65-degrees-W). No significant accumulation of compression normal to the strike of the San Andreas fault was observed in the network as a whole. RP SAVAGE, JC (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 977,MENLO PK,CA 94025, USA. NR 9 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 JUN 15 PY 1994 VL 21 IS 12 BP 1173 EP 1176 DI 10.1029/94GL01123 PG 4 WC Geosciences, Multidisciplinary SC Geology GA NT217 UT WOS:A1994NT21700019 ER PT J AU MCLEAN, SR NELSON, JM WOLFE, SR AF MCLEAN, SR NELSON, JM WOLFE, SR TI TURBULENCE STRUCTURE OVER 2-DIMENSIONAL BED FORMS - IMPLICATIONS FOR SEDIMENT TRANSPORT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article; Proceedings Paper CT Miniconference on Observation and Modeling of North Atlantic Deep Water Formation and its Variability CY NOV, 1991 CL COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV, PALISADES, NY HO COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV ID LOAD TRANSPORT; FLOW; RIPPLES; MODEL; DUNES AB Turbulence measurements from the flow over two-dimensional fixed dune shapes are presented along with analysis and discussion of the ramifications of the observations for transport of sediment as bed load over bed forms. The spatial structure of the local transport rate determines the shape and stability of bed forms such as ripples and dunes, and the transport of sediment is a highly nonlinear process that is profoundly affected by the statistics of the temporal fluctuations in the near-bed flow field. The measurements presented herein show strong spatial evolution of the joint probability distribution of the streamwise and bednormal fluctuating velocity components. Unlike measurements in uniform boundary layers, these distributions and the higher moments of the velocity do not scale with the local shear velocity, indicating that it is probably inappropriate to use the shear stress to characterize the sediment flux. This conclusion is supported by observations of sediment flux over a dune. C1 US GEOL SURVEY,DIV WATER RESOURCES,DENVER,CO 80225. RP MCLEAN, SR (reprint author), UNIV CALIF SANTA BARBARA,DEPT MECH & ENVIRONM ENGN,SANTA BARBARA,CA 93106, USA. NR 25 TC 130 Z9 133 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1994 VL 99 IS C6 BP 12729 EP 12747 DI 10.1029/94JC00571 PG 19 WC Oceanography SC Oceanography GA NT504 UT WOS:A1994NT50400030 ER PT J AU BROCHER, TM FUIS, GS FISHER, MA PLAFKER, G MOSES, MJ TABER, JJ CHRISTENSEN, NI AF BROCHER, TM FUIS, GS FISHER, MA PLAFKER, G MOSES, MJ TABER, JJ CHRISTENSEN, NI TI MAPPING THE MEGATHRUST BENEATH THE NORTHERN GULF OF ALASKA USING WIDE-ANGLE SEISMIC DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COPPER RIVER BASIN; SOUTHERN ALASKA; CHUGACH MOUNTAINS; CRUSTAL TRANSECT; AMERICAN PLATE; REFLECTION REFRACTION; TERRANES; VELOCITIES; EVOLUTION; BOUNDARY AB In the northern Gulf of Alaska and Prince William Sound, we have used wide-angle seismic reflection/refraction profiles, earthquake studies, and laboratory measurements of physical properties to determine the geometry of the Prince William and Yakutat terranes, the Aleutian megathrust, and the subducting Pacific plate. In this complex region, the Yakutat terrane is underthrust beneath the Prince William terrane, and both terranes are interpreted to be underlain by the Pacific plate. Wide-angle seismic reflection/refraction profiles recorded along five seismic lines are used to unravel this terrane geometry. Modeled velocities in the upper crust of the Prince William terrane (to 18 km depth) agree closely with laboratory velocity measurements of Orca Group phyllites and quartzofeldspathic graywackes (the chief components of the Prince William terrane) to hydrostatic pressures as high as 600 MPa (6 kbar). A landward dipping reflector at depths of 16-24 km is interpreted as the base of the Prince William terrane. This reflector corresponds to the top of the Wadati-Benioff zone seismicity and is interpreted as the megathrust. Immediately beneath the megathrust is a 4-km-thick 6.9-km/s refractor, which we infer to be the source of a prominent magnetic anomaly and which is interpreted by us and previous workers to be gabbro in Eocene age oceanic crust of the underthrust Yakutat terrane. Wide-angle seismic data, magnetic anomaly data, and tectonic reconstructions indicate that the Yakutat terrane has been underthrust beneath the Prince William terrane for at least a few hundred kilometers. Wide-angle seismic data are consistent with a 9-degrees to 10-degrees landward dip of the subducting Pacific plate beneath the outer shelf and slope, distinctly different from the inferred average 3-degrees- to 4-degrees dip of the overlying 6.9-km/s refractor and the Wadati-Benioff seismic zone beneath the inner shelf. Our preferred interpretation of the geophysical data is that one composite plate, composed of the Pacific plate of a fairly uniform thickness and the Yakutat plate of varying thickness, is subducting beneath southern Alaska. C1 PURDUE UNIV, DEPT EARTH & ATMOSPHER SCI, W LAFAYETTE, IN 47907 USA. VICTORIA UNIV WELLINGTON, INST GEOPHYS, WELLINGTON, NEW ZEALAND. RP BROCHER, TM (reprint author), US GEOL SURVEY, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 46 TC 98 Z9 99 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 1994 VL 99 IS B6 BP 11663 EP 11685 DI 10.1029/94JB00111 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NT168 UT WOS:A1994NT16800005 ER PT J AU LI, YG AKI, K ADAMS, D HASEMI, A LEE, WHK AF LI, YG AKI, K ADAMS, D HASEMI, A LEE, WHK TI SEISMIC GUIDED-WAVES TRAPPED IN THE FAULT ZONE OF THE LANDERS, CALIFORNIA, EARTHQUAKE OF 1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID STRONG GROUND MOTION; QUANTITATIVE DESCRIPTION; BARRIER MODEL; ACCELERATION; ANISOTROPY; PREDICTION; AMPLITUDE; VALLEY; FMAX AB A mobile seismic array of seven stations was deployed at 11 sites along the fault trace of the M7.4 Landers earthquake of June 28, 1992, with a maximum offset of 1 km from the trace. We found a distinct wave train with a relatively long period following the S waves that shows up only when both the stations and the events are close to the fault trace. This wave train is interpreted as a seismic guided wave trapped in a low-velocity fault zone. To study the distribution of amplitude of the guided waves with distance from the fault trace and also their attenuation with travel distance along the fault zone, we eliminated source and recording site effects by the coda normalization method. The normalized amplitudes of guided waves show a spectral peak at 3-4 Hz, which decays sharply with distance from the fault trace. Spectral amplitudes at high frequencies (8-15 Hz) show an opposite trend, increasing with distance from the fault trace. The normalized amplitudes of guided waves at 3-4 Hz also show a systematic decrease with hypocentral distance along the fault zone, from which we infer an apparent Q of 50. In order to confirm the existence of the guided waves, a dense array of 31 stations was deployed at one of the 11 sites. The resultant records revealed unequivocal evidence for the existence of guided waves associated with the fault zone. By modeling the waveforms as S waves trapped in a low-velocity waveguide sandwiched between two homogeneous half-spaces with velocity V(s) = 3.0 km/s, we infer a waveguide width of about 180 m, a shear velocity of 2.0-2.2 km/s, and a Q of approximately 50. Hypocenters of aftershocks with clear guided waves show a systematic distribution both laterally and with depth delineating the extent of the low-velocity fault zone in three dimensions. We find that the zone extends to a depth of at least 10 km. This zone apparently continues to the south across the Pinto Mountain fault because guided waves are observed at stations north of the Pinto Mountain fault for earthquakes with epicenters south of it. On the other hand, the zone appears to be discontinuous at the fault bend located about 20 km north of the mainshock epicenter; guided waves were observed for stations and epicenters which are located on the same sides of the fault bend but not for those on the opposite sides. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP LI, YG (reprint author), UNIV SO CALIF, DEPT EARTH SCI, UNIV PK, LOS ANGELES, CA 90089 USA. NR 35 TC 136 Z9 145 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 JUN 10 PY 1994 VL 99 IS B6 BP 11705 EP 11722 DI 10.1029/94JB00464 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NT168 UT WOS:A1994NT16800007 ER PT J AU JULIAN, BR AF JULIAN, BR TI VOLCANIC TREMOR - NONLINEAR EXCITATION BY FLUID-FLOW SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MOUNT ST-HELENS; DRIVEN CRACK; SOURCE MODEL; EARTHQUAKES; SEISMICITY; MECHANISM; DYNAMICS; KILAUEA; APRIL AB A nonlinear process analogous to the excitation mechanism of musical wind instruments and human vocal cords can explain many characteristics of volcanic tremor, including (1) periodic and ''chaotic'' oscillations, with peaked and irregular spectra respectively, (2) rapid pulsations in eruptions occurring at the same frequency as tremor, (3) systematic changes in tremor amplitude as channel geometry evolves during an eruption, (4) the period doubling reported for Hawaiian deep tremor, and (5) the fact that the onset of tremor can be either gradual or abrupt. Volcanic ''long-period'' earthquakes can be explained as oscillations excited by transient disturbances produced by nearby earthquakes, fluid heterogeneity, or changes in channel geometry, when the magma flow rate is too low to excite continuous tremor. A simple lumped-parameter tremor model involving the flow of an incompressible viscous fluid through a channel with movable elastic walls leads to a third-order system of nonlinear ordinary differential equations. For different driving fluid pressures, numerical solutions exhibit steady flow, simple limit-cycle oscillations, a cascade of period-doubling subharmonic bifurcations, and chaotic oscillations controlled by a strange attractor of Rossler type. In this model, tremor occurs most easily at local constrictions, and fluid discharge is lower than would occur in unstable steady flow. RP JULIAN, BR (reprint author), US GEOL SURVEY, MAIL STOP 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 72 TC 195 Z9 199 U1 0 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 JUN 10 PY 1994 VL 99 IS B6 BP 11859 EP 11877 DI 10.1029/93JB03129 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NT168 UT WOS:A1994NT16800020 ER PT J AU CARSON, B SEKE, E PASKEVICH, V HOLMES, ML AF CARSON, B SEKE, E PASKEVICH, V HOLMES, ML TI FLUID EXPULSION SITES ON THE CASCADIA ACCRETIONARY PRISM - MAPPING DIAGNETIC DEPOSITS WITH PROCESSED GLORIA IMAGERY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID OREGON SUBDUCTION ZONE; CARBONATES; MARGIN; FLOW; SEEPAGE; SLOPE; WATER AB Point-discharge fluid expulsion on accretionary prisms is commonly indicated by diagenetic deposition of calcium carbonate cements and gas hydrates in near-surface (<10 m below seafloor; mbsf) hemipelagic sediment. The contrasting clastic and diagenetic lithologies should be apparent in side scan images. However, sonar also responds to variations in bottom slope, so unprocessed images mix topographic and lithologic information. We have processed GLORIA imagery from the Oregon continental margin to remove topographic effects. A synthetic side scan image was created initially from Sea Beam bathymetric data and then was subtracted iteratively from the original GLORIA data until topographic features disappeared. The residual image contains high-amplitude backscattering that we attribute to diagenetic deposits associated with fluid discharge, based on submersible mapping, Ocean Drilling Program drilling, and collected samples. Diagenetic deposits are concentrated (1) near an out-of-sequence thrust fault on the second ridge landward of the base of the continental slope, (2) along zones characterized by deep-seated strike-slip faults that cut transversely across the margin, and (3) in undeformed Cascadia Basin deposits which overlie incipient thrust faults seaward of the toe of the prism. There is no evidence of diagenetic deposition associated with the frontal thrust that rises from the decollement. If the decollement is an important aquifer, apparently the fluids are passed either to the strike-slip faults which intersect the decollement or to the incipient faults in Cascadia Basin for expulsion. Diagenetic deposits seaward of the prism toe probably consist dominantly of gas hydrates. C1 UNIV WASHINGTON, US GEOL SURVEY, SCH OCEANOG, SEATTLE, WA 98195 USA. US GEOL SURVEY, WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. LEHIGH UNIV, DEPT ELECT ENGN & COMP SCI, BETHLEHEM, PA 18015 USA. RP CARSON, B (reprint author), LEHIGH UNIV, DEPT EARTH & ENVIRONM SCI, 31 WILLIAMS DR, BETHLEHEM, PA 18015 USA. NR 31 TC 38 Z9 38 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 JUN 10 PY 1994 VL 99 IS B6 BP 11959 EP 11969 DI 10.1029/94JB00120 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NT168 UT WOS:A1994NT16800027 ER PT J AU MEYERS, TR SHORT, S LIPSON, K BATTS, WN WINTON, JR WILCOCK, J BROWN, E AF MEYERS, TR SHORT, S LIPSON, K BATTS, WN WINTON, JR WILCOCK, J BROWN, E TI ASSOCIATION OF VIRAL HEMORRHAGIC SEPTICEMIA VIRUS WITH EPIZOOTIC HEMORRHAGES OF THE SKIN IN PACIFIC HERRING CLUPEA-HARENGUS-PALLASI FROM PRINCE WILLIAM SOUND AND KODIAK ISLAND, ALASKA, USA SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE VHSV; HERRING; HEMORRHAGES AB Only one-third of the Pacific herring Clupea harengus pallasi expected to spawn in Prince William Sound (PWS), Alaska, USA, in spring 1993 were observed. Of these herring, 15 to 43 % had external ulcers or subdermal hemorrhages of the skin and fins. A rhabdovirus identified as the North American strain of viral hemorrhagic septicemia virus (VHSV) was isolated from affected herring and 1 Pacific cod Gadus macrocephalus with skin lesions from PWS, and from herring with similar lesions collected near Kodiak Island. No other pathogens were detected in the herring examined. Although VHSV may have been responsible for the skin lesions, there was no confirmed mass herring mortality observed in PWS; hence the actual cause of the reduced herring numbers is still unknown. The same strain of VHSV was subsequently isolated from captive juvenile herring collected from Auke Bay, Alaska, near Juneau, from herring in British Columbia, Canada, and from Puget Sound, Washington, USA. These findings suggest the virus is an opportunistic pathogen that is widely indigenous to Pacific herring populations in the Pacific Northwest and that herring are a significant marine reservoir for North American VHSV. C1 US FISH & WILDLIFE SERV,NATL FISHERIES RES CTR,NAVAL STN,SEATTLE,WA 98115. ALASKA DEPT FISH & GAME,DIV COMMERCIAL FISHERIES MANAGEMENT & DEV,CORDOVA,AK 99574. RP MEYERS, TR (reprint author), ALASKA DEPT FISH & GAME,DIV COMMERCIAL FISHERIES MANAGEMENT & DEV,FISH PATHOL SECT,JUNEAU,AK 99802, USA. NR 22 TC 102 Z9 107 U1 1 U2 6 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD JUN 9 PY 1994 VL 19 IS 1 BP 27 EP 37 DI 10.3354/dao019027 PG 11 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA PA586 UT WOS:A1994PA58600005 ER PT J AU REVENAUGH, J SIPKIN, SA AF REVENAUGH, J SIPKIN, SA TI SEISMIC EVIDENCE FOR SILICATE MELT ATOP THE 410 KM MANTLE DISCONTINUITY SO NATURE LA English DT Article ID SCS REVERBERATIONS; MOLTEN KOMATIITE; CRUSTAL GROWTH; DIFFERENTIATION; COMPRESSION; LIQUID; MODELS; PHASE; PERIDOTITE; INVERSION AB LABORATORY results demonstrating that basic to ultrabasic melts become denser than olivine-rich mantle at pressures above 6 GPa (refs 1-3) have important implications for basalt petrogenesis, mantle differentiation and the storage of volatiles deep in the Earth. A density cross-over between melt and solid in the extensively molten Archaean mantle has been inferred from komatiitic volcanism(4-6) and major-element mass balances?, but present-day evidence of dense melt below the seismic low-velocity zone is lacking. Here we present mantle shear-wave impedance profiles obtained from multiple-ScS reverberation mapping for corridors connecting western Pacific subduction zone earthquakes?with digital seismograph stations in eastern China, imaging a similar to 5.8% impedance decrease roughly 330 km beneath the Sea of Japan, Yellow Sea and easternmost Asia. We propose that this represents the upper surface of a layer of negatively buoyant melt lying on top of the olivine-->beta-phase transition (the 410-km seismic discontinuity). Volatile-rich fluids expelled from the partial melt zone as it freezes may migrate upwards, acting as metasomatic agents(8,9) and perhaps as the deep 'proto-source' of kimberlites(10,11). The remaining, dense, crystalline fraction mould then concentrate above 410 km, producing a garnet-rich layer that may Rush into the transition zone. C1 US GEOL SURVEY,GOLDEN,CO 80401. RP REVENAUGH, J (reprint author), UNIV CALIF SANTA CRUZ,INST TECTON,SANTA CRUZ,CA 95064, USA. NR 31 TC 176 Z9 185 U1 2 U2 25 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUN 9 PY 1994 VL 369 IS 6480 BP 474 EP 476 DI 10.1038/369474a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NQ286 UT WOS:A1994NQ28600053 ER PT J AU KOPASKAMERKEL, DC MANN, SD SCHMOKER, JW AF KOPASKAMERKEL, DC MANN, SD SCHMOKER, JW TI CONTROLS ON RESERVOIR DEVELOPMENT IN A SHELF CARBONATE - UPPER JURASSIC SMACKOVER FORMATION OF ALABAMA SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID NORTHEASTERN GULF-COAST; DOLOMITE-ROCK TEXTURES; BURIAL DIAGENESIS; CONECUH EMBAYMENT; POROSITY; FIELD; EVOLUTION; ORIGIN; TEXAS; CLASSIFICATION AB Hydrocarbon reservoirs of the Upper Jurassic Smackover Formation in Alabama are predominately oolitic and pelletal dolostone. Pore systems are dominated by moldic and secondary intraparticle pores, intercrystalline pores, or mixtures of these pore types. All Smackover reservoirs in Alabama have been strongly affected by early cementation, dissolution of calcium-carbonate allochems, and dolomitization. Marine-phreatic cement occluded primary interparticle porosity in much of the Smackover reservoirs in Alabama. Dolomitization of the Smackover in Alabama included penecontemporaneous, early burial, and late (deep) burial episodes. Early burial dolomite predominates. Fabric-selective dolomitization yielded reservoirs strongly influenced by both depositional fabric and diagenesis. Nonselective dolomitization yielded reservoirs with intercrystalline pore systems shaped primarily by diagenesis. Porosity evolution was controlled regionally by level of thermal exposure, mode of dolomitization, and proximity to the Wiggins arch. Thermal exposure is inversely related to porosity, but the relationship is weak (r2 < 0.5). Fabric-selective dolostone is slightly more porous than nonselective dolostone when averaged over the entire study area (averages of 18.1% and 15.1%, respectively; p = 0.0001), but nonselective dolostone is more porous at a given level of equivalent vitrinite reflectance. Smackover fields on the north flank of the Wiggins arch are unusually porous given their level of thermal maturity, and are unusual in other ways as well. Local porosity variation was controlled by depositional fabric, early cementation, dissolution, and burial compaction and cementation. Regional permeability variation cannot be explained using existing data. Permeability is locally controlled by pore-throat size, the effects of dolomite crystal-size distribution, early cementation, fracturing, and burial compaction and cementation. Pore-throat size exhibits the strongest overall correlation with permeability (r2 = 0.54). Permeability and porosity are strongly correlated locally, but the regional correlation is weak. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP KOPASKAMERKEL, DC (reprint author), US GEOL SURVEY,POB O,TUSCALOOSA,AL 35486, USA. NR 74 TC 9 Z9 9 U1 0 U2 2 PU AMER ASSOC PETROLEUM GEOLOGIST 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 JUN PY 1994 VL 78 IS 6 BP 938 EP 959 PG 22 WC Geosciences, Multidisciplinary SC Geology GA NR113 UT WOS:A1994NR11300005 ER PT J AU PASHIN, JC AF PASHIN, JC TI COAL-BODY GEOMETRY AND SYNSEDIMENTARY DETACHMENT FOLDING IN OAK-GROVE COALBED METHANE FIELD, BLACK-WARRIOR BASIN, ALABAMA SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID DEPOSITIONAL MODELS; FORELAND; BELT AB Intensive drilling in Oak Grove field, the largest coalbed methane field in the Black Warrior basin of Alabama, presents an opportunity to determine the relationship between tectonism and sedimentation in the Lower Pennsylvanian Pottsville Formation along the southwestern terminus of an Alleghanian thrust sheet. Stratigraphic and sedimentologic relationships in and around the thrust sheet indicate a synsedimentary phase of detachment folding. This deformation had a major impact on the distribution, thickness, and geometry of coalbed methane reservoirs. The sedimentologic expression of detachment folding differs in each depositional cycle of the Pottsville Formation, reflecting the dynamically interwoven variables of biologic, tectonic, and terrigenous-clastic systems. RP PASHIN, JC (reprint author), US GEOL SURVEY,POB O,TUSCALOOSA,AL 35486, USA. NR 53 TC 12 Z9 12 U1 0 U2 1 PU AMER ASSOC PETROLEUM GEOLOGIST 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 JUN PY 1994 VL 78 IS 6 BP 960 EP 980 PG 21 WC Geosciences, Multidisciplinary SC Geology GA NR113 UT WOS:A1994NR11300006 ER PT J AU YOUNG, JR HUPP, JW BRADBURY, JW BRAUN, CE AF YOUNG, JR HUPP, JW BRADBURY, JW BRAUN, CE TI PHENOTYPIC DIVERGENCE OF SECONDARY SEXUAL TRAITS AMONG SAGE GROUSE, CENTROCERCUS-UROPHASIANUS, POPULATIONS SO ANIMAL BEHAVIOUR LA English DT Article ID SELECTION; SPECIATION C1 US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. COLORADO DIV WILDLIFE,FT COLLINS,CO 80526. UNIV CALIF SAN DIEGO,DEPT BIOL C016,LA JOLLA,CA 92093. RP YOUNG, JR (reprint author), PURDUE UNIV,DEPT BIOL SCI,W LAFAYETTE,IN 47907, USA. NR 39 TC 46 Z9 47 U1 2 U2 15 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0003-3472 J9 ANIM BEHAV JI Anim. Behav. PD JUN PY 1994 VL 47 IS 6 BP 1353 EP 1362 DI 10.1006/anbe.1994.1183 PG 10 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA NQ458 UT WOS:A1994NQ45800010 ER PT J AU SMITH, RL CEAZAN, ML BROOKS, MH AF SMITH, RL CEAZAN, ML BROOKS, MH TI AUTOTROPHIC, HYDROGEN-OXIDIZING, DENITRIFYING BACTERIA IN GROUNDWATER, POTENTIAL AGENTS FOR BIOREMEDIATION OF NITRATE CONTAMINATION SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID BIOLOGICAL DENITRIFICATION; PARACOCCUS-DENITRIFICANS; GRAVEL AQUIFER; DRINKING-WATER; SANDY AQUIFER; NITROUS-OXIDE; REDUCTION; KINETICS; OXYGEN; SOILS AB Addition of hydrogen or formate significantly enhanced the rate of consumption of nitrate in slurried core samples obtained from an active zone of denitrification in a nitrate-contaminated sand and gravel aquifer (Cape Cod, Mass.). Hydrogen uptake by the core material was immediate and rapid, with an apparent K-m of 0.45 to 0.60 mu M and a V-max of 18.7 nmol cm(-3) h(-1) at 30 degrees C. Nine strains of hydrogen-oxidizing denitrifying bacteria sere subsequently isolated from the aquifer. Eight of the strains grew autotrophically on hydrogen with either oxygen or nitrate as the electron acceptor. One strain grew mixotrophically. All of the isolates were capable of heterotrophic growth, but none were similar to Paracoccus denitrificans, a well-characterized hydrogen-oxidizing denitrifier. The kinetics for hydrogen uptake during denitrification were determined for each isolate with substrate depletion progress curves; the K(m)s ranged from 0.30 to 3.32 mu M, with V(max)s of 1.85 to 13.29 fmol cell(-1) h(-1). Because these organisms appear to be common constituents of the in situ population of the aquifer, produce innocuous end products, and could be manipulated to sequentially consume oxygen and then nitrate when both were present, these results suggest that these organisms may have significant potential for in situ bioremediation of nitrate contamination in groundwater. RP SMITH, RL (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,3215 MARINE ST,BOULDER,CO 80303, USA. RI Smith, Richard/A-6733-2008 OI Smith, Richard/0000-0002-3829-0125 NR 33 TC 68 Z9 70 U1 0 U2 14 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 1994 VL 60 IS 6 BP 1949 EP 1955 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA NN765 UT WOS:A1994NN76500035 PM 16349284 ER PT J AU BRADLEY, PM CHAPELLE, FH LANDMEYER, JE SCHUMACHER, JG AF BRADLEY, PM CHAPELLE, FH LANDMEYER, JE SCHUMACHER, JG TI MICROBIAL TRANSFORMATION OF NITROAROMATICS IN SURFACE SOILS AND AQUIFER MATERIALS SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Note ID FUNGUS PHANEROCHAETE-CHRYSOSPORIUM; SP B-STRAIN; 2,4,6-TRINITROTOLUENE TNT; CONTAMINATED SOILS; 2,4-DINITROTOLUENE; DEGRADATION; BIOTRANSFORMATION; BIODEGRADATION; IDENTIFICATION AB Microorganisms indigenous to surface soils and aquifer materials collected at a munitions-contaminated site transformed 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,6-dinitrotoluene (2,6-DNT) to amino-nitro intermediates within 20 to 70 days. Carbon mineralization studies with both unlabeled (TNT, 2,4-DNT, and 2,6-DNT) and radiolabeled ([C-14]TNT) substrates indicated that a significant fraction of these source compounds was degraded to CO2. C1 US GEOL SURVEY,DIV WATER RESOURCES,ROLLA,MO 65401. RP BRADLEY, PM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,STEPHENSON CTR,COLUMBIA,SC 29210, USA. NR 29 TC 64 Z9 66 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 JUN PY 1994 VL 60 IS 6 BP 2170 EP 2175 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA NN765 UT WOS:A1994NN76500070 PM 16349303 ER PT J AU MONOSSON, E FLEMING, WJ SULLIVAN, CV AF MONOSSON, E FLEMING, WJ SULLIVAN, CV TI EFFECTS OF THE PLANAR PCB 3,3',4,4'-TETRACHLOROBIPHENYL (TCB) ON OVARIAN DEVELOPMENT, PLASMA-LEVELS OF SEX STEROID-HORMONES AND VITELLOGENIN, AND PROGENY SURVIVAL IN THE WHITE PERCH (MORONE-AMERICANA) SO AQUATIC TOXICOLOGY LA English DT Article DE REPRODUCTION; PCB; FISH; WHITE PERCH; 3,3',4,4'-TETRACHLOROBIPHENYL ID POLYCHLORINATED BIPHENYL PCB; SOLE PAROPHRYS-VETULUS; KRAFT MILL EFFLUENT; RAINBOW-TROUT; AROCLOR 1254; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN TCDD; REPRODUCTIVE SUCCESS; MFO ACTIVITY; PUGET SOUND; FISH AB Adult white perch were given three intraperitoneal injections of 3,3',4,4'-tetrachlorobiphenyl (TCB) at one of three different doses (0.2-5.0 mg TCB/kg body weight). The TCB injections were initiated approx. 3 months prior to the spawning season and given at 3-week intervals. Fewer females matured in the group receiving the highest dose of TCB. Those fish that did mature had a gonadal somatic index approximately half that of control females. Circulating levels of the sex steroid hormones, estradiol-17beta and testosterone, and of the egg yolk precursor, vitellogenin, were not significantly altered by TCB exposure. By 7 days post-hatch survival of larvae produced from females exposed to 1.0 and 5.0 mg/kg TCB was reduced as compared to controls (0, 1 and 54%, respectively). These results show that: (1) TCB impairs both maturation of adult females and survival of their offspring, and (2) decreased larval survival may occur at TCB doses less than those required to decrease ovarian growth, oocyte maturation, or circulating sex steroid hormone and vitellogenin concentrations in the adult fish. C1 N CAROLINA STATE UNIV,DEPT ZOOL,RALEIGH,NC 27695. N CAROLINA STATE UNIV,US FISH & WILDLIFE SERV,RALEIGH,NC 27695. RI Sullivan, Craig/B-3863-2014 OI Sullivan, Craig/0000-0002-3609-9458 NR 64 TC 59 Z9 62 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-445X J9 AQUAT TOXICOL JI Aquat. Toxicol. PD JUN PY 1994 VL 29 IS 1-2 BP 1 EP 19 DI 10.1016/0166-445X(94)90044-2 PG 19 WC Marine & Freshwater Biology; Toxicology SC Marine & Freshwater Biology; Toxicology GA NX445 UT WOS:A1994NX44500001 ER PT J AU PRICE, LC LEFEVER, J AF PRICE, LC LEFEVER, J TI DYSFUNCTIONALISM IN THE WILLISTON BASIN - THE BAKKEN MID-MADISON PETROLEUM SYSTEM SO BULLETIN OF CANADIAN PETROLEUM GEOLOGY LA English DT Article AB Analyses of fifteen oils produced from fractured shales of the Upper Devonian and Lower Mississippian Bakken Formation in the Williston Basin were compared to the same analyses for eighteen Williston Basin oils produced from conventional reservoirs in the middle of the Lower and Upper Mississippian Madison Group. All oils came from the U.S.A. portion of the Williston Basin. These comparisons demonstrate that, contrary to previous studies and the models developed from those studies, the Bakken and mid-Madison oils are different oil families from different source rocks. Our findings thus agree with recent work on the Canadian side of the Williston Basin (Osadetz et al., 1992). Within the saturated hydrocarbons (HCs) the Bakken oils are more naphthenic, less paraffinic (especially less waxy), have different n-paraffin and isoprenoid-HC profiles, and have different compound ratios for ''generic'' saturated HCs, as compared to the Madison oils. Within the aromatic HCs the mid-Madison oils have an unusual trimethylnaphthalene distribution, high concentrations of dibenzothiophenes and alkylated variants thereof, and different aromatic-HC peak distributions in general (and thus different aromatic-HC compound ratio plots), as compared to the Bakken oils. Because of wide maturity ranges in both oil sets, biomarkers were of limited utility as source-facies indices and thus as correlation tools. We have not yet found any oil generated by the Bakken shales or any mixing of Bakken and Madison oils in a Madison reservoir. We believe the range of variation in our correlation indices to be too large among the Madison oils for these oils to have a single source rock. For this and other reasons, we hypothesize that the Madison oils are from separate source rocks interbedded with the different mid-Madison reservoirs in the basin, rocks which appear to have the same, or very similar, depositional environments. Thus, the original Bakken/mid-Madison petroleum system appears dysfunctional. The results of this study have significant implications for: 1) models of both oil expulsion and deep-basin fluid flow; and 2) the possible existence of very large oil-resource bases in mature, organic-rich, fractured, fine-grained rocks in petroleum basins worldwide. RP PRICE, LC (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS940,DENVER,CO 80225, USA. NR 0 TC 28 Z9 29 U1 1 U2 13 PU CANADIAN SOC PETROL GEOLOGISTS PI CALGARY PA 505, 206 - 7TH AVE SW, CALGARY AB T2P 0W7, CANADA SN 0007-4802 J9 B CAN PETROL GEOL JI Bull. Can. Pet. Geol. PD JUN PY 1994 VL 42 IS 2 BP 187 EP 218 PG 32 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA NU427 UT WOS:A1994NU42700004 ER PT J AU JOHNSON, AM FLEMING, RW CRUIKSHANK, KM AF JOHNSON, AM FLEMING, RW CRUIKSHANK, KM TI SHEAR ZONES FORMED ALONG LONG, STRAIGHT TRACES OF FAULT ZONES DURING THE 28 JUNE 1992 LANDERS, CALIFORNIA, EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID STRUCTURAL-ANALYSIS; LOMA-PRIETA; FRACTURES AB Surface rupturing during the 28 June 1992 Landers, California, earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en-echelon fault zones with a total length of 80 km. The offsets were accommodated generally not by faults-distinct slip surfaces-but rather by shear zones, tabular bands of localized shearing. Along simple stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with clearly defined, subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few meters wide) shear zones that accommodate most of the offset of the belt and are portrayed by en-echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left-lateral shearing, and the slices were forced against the walls of the shear zone, producing thrusting. Even narrower shear zones formed within the narrow shear zones. Although these probably are guides to right-lateral fault segments below, the surface rupturing during the earthquake is characterized not by faulting, but by the formation of shear zones at various scales. C1 PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,RICHARD H JAHNS ENGN GEOL LAB,W LAFAYETTE,IN 47907. RP JOHNSON, AM (reprint author), US GEOL SURVEY,GEOL RISK ASSESSMENT BRANCH,LAKEWOOD,CO 80225, USA. NR 23 TC 62 Z9 64 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 1994 VL 84 IS 3 BP 499 EP 510 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300002 ER PT J AU FRANKEL, A AF FRANKEL, A TI DENSE ARRAY RECORDINGS IN THE SAN-BERNARDINO VALLEY OF LANDERS-BIG-BEAR AFTERSHOCKS - BASIN SURFACE-WAVES, MOHO REFLECTIONS, AND 3-DIMENSIONAL SIMULATIONS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LOMA-PRIETA EARTHQUAKE; GROUND MOTIONS; CALIFORNIA; FRANCISCO; PATH AB Fourteen GEOS seismic recorders were deployed in the San Bernardino Valley to study the propagation of short-period (T almost-equal-to 1 to 3 sec) surface waves and Moho reflections. Three dense arrays were used to determine the direction and speed of propagation of arrivals in the seismograms. The seismograms for a shallow (d almost-equal-to 1 km) M 4.9 aftershock of the Big Bear earthquake exhibit a very long duration (60 sec) of sustained shaking at periods of about 2 sec. Array analysis indicates that these late arrivals are dominated by surface waves traveling in various directions across the Valley. Some energy is arriving from a direction 180-degrees from the epicenter and was apparently reflected from the edge of the Valley opposite the source. A close-in aftershock (DELTA = 25 km, depth = 7 km) displays substantial short-period surface waves at deep-soil sites. A three-dimensional (3D) finite difference simulation produces synthetic seismograms with durations similar to those of the observed records for this event, indicating the importance of S-wave to surface-wave conversion near the edge of the basin. Flat-layered models severely underpredict the duration and spectral amplification of this deep-soil site. I show an example where the coda wave amplitude ratio at 1 to 2 Hz between a deep-soil and a rock site does not equal the S-wave amplitude ratio, because of the presence of surface waves in the coda of the deep-soil site. For one of the events studied (DELTA almost-equal-to 90 km), there are sizable phases that are critically reflected from the Moho (PmP and SmS). At one of the rock sites, the SmS phase has a more peaked spectrum that the direct S wave. RP FRANKEL, A (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 966,BOX 25046,DENVER,CO 80225, USA. NR 19 TC 28 Z9 28 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 1994 VL 84 IS 3 BP 613 EP 624 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300011 ER PT J AU HUDNUT, KW BOCK, Y CLINE, M FANG, P FENG, Y FREYMUELLER, J GE, X GROSS, WK JACKSON, D KIM, M KING, NE LANGBEIN, J LARSEN, SC LISOWSKI, M SHEN, ZK SVARC, J ZHANG, J AF HUDNUT, KW BOCK, Y CLINE, M FANG, P FENG, Y FREYMUELLER, J GE, X GROSS, WK JACKSON, D KIM, M KING, NE LANGBEIN, J LARSEN, SC LISOWSKI, M SHEN, ZK SVARC, J ZHANG, J TI COSEISMIC DISPLACEMENTS OF THE 1992 LANDERS EARTHQUAKE SEQUENCE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; GLOBAL POSITIONING SYSTEM; CRUSTAL DEFORMATION; 2-COLOR GEODIMETER; JUNE 1992; SOUTHERN CALIFORNIA; EASTERN CALIFORNIA; INTERFEROMETRY; STRESS; FIELD AB We present co-seismic displacement vectors derived from Global Positioning System (GPS) measurements of 92 stations in southern California. These GPS results are combined with five well-determined GPS displacement vectors from continuously tracking stations of the Permanent GPS Geodetic Array, as well as line-length changes from USGS Geodolite and two-color laser trilateration observations, to determine a self-consistent set of geodetic data for the earthquake. These combined displacements are modeled by an elastic dislocation representation of the primary fault rupture planes. On average, the model residuals are about twice the estimated measurement errors. C1 STANFORD UNIV, INST GEOL SCI, STANFORD, CA 94305 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, IGPP, LA JOLLA, CA 92093 USA. RP HUDNUT, KW (reprint author), US GEOL SURVEY, PASADENA, CA 91106 USA. RI Jackson, David/A-9828-2008; Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010 OI Jackson, David/0000-0001-7913-5714; Hudnut, Kenneth/0000-0002-3168-4797; NR 48 TC 85 Z9 89 U1 0 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1994 VL 84 IS 3 BP 625 EP 645 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300012 ER PT J AU FREYMUELLER, J KING, NE SEGALL, P AF FREYMUELLER, J KING, NE SEGALL, P TI THE COSEISMIC SLIP DISTRIBUTION OF THE LANDERS EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID MOJAVE-DESERT; EASTERN CALIFORNIA; 1992 LANDERS; SHEAR ZONE; DEFORMATION; SEQUENCE; FAULT; DISPLACEMENTS; DEPTH AB We derived a model for the co-seismic slip distribution on the faults which ruptured during the Landers earthquake sequence of 28 June 1992. The model is based on the inversion of surface geodetic measurements, primarily vector displacements measured using the Global Positioning System (GPS). The inversion procedure assumes that the slip distribution is to some extent smooth and purely right-lateral strike slip. For a given fault geometry, a family of solutions of varying smoothness can be generated. We choose the optimal model from this family based on cross-validation, which measures the predictive power of the data, and the trade-off of misfit and roughness. Solutions which give roughly equal weight to misfit and smoothness are preferred and have certain features in common: (1) there are two main patches of slip, on the Johnson Valley fault, and on the Homestead Valley, Emerson, and Camp Rock faults; (2) virtually all slip is in the upper 10 to 12 km; and (3) the model reproduces the general features of the geologically measured surface displacements, without prior constraints on the surface slip. In all models, regardless of smoothing, very little slip is required on the fault that represents the Big Bear event, and the total moment of the Landers event is 9 . 10(19) N-m. The nearly simultaneous rupture of multiple distinct faults suggests that much of the crust in this region must have been close to failure prior to the earthquake. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP FREYMUELLER, J (reprint author), STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305, USA. NR 27 TC 58 Z9 58 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 JUN PY 1994 VL 84 IS 3 BP 646 EP 659 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300013 ER PT J AU JOHNSON, HO AGNEW, DC HUDNUT, K AF JOHNSON, HO AGNEW, DC HUDNUT, K TI EXTREMAL BOUNDS ON EARTHQUAKE MOVEMENT FROM GEODETIC DATA - APPLICATION TO THE LANDERS EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; CRUSTAL DEFORMATION; BORAH PEAK; CALIFORNIA; INVERSION; DISPLACEMENTS; PARKFIELD; SEQUENCE; SLIP AB We present a technique to place quantifiable bounds on the moment of an earthquake from geodetic data, assuming known fault geometry. Application of this technique to the 1992 Landers earthquake shows that the moment must have been between 0.84 and 1.15 x 10(20) Nm with 90% confidence (M 7.25 to 7.34). We also find that to satisfy the data to this same level of confidence, the slip on the fault must have exceeded 7 m in at least one location, in good agreement with field mapping of the surface rupture. C1 US GEOL SURVEY,PASADENA,CA 91106. RP JOHNSON, HO (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,INST GEOPHYS & PLANETARY PHYS,LA JOLLA,CA 92093, USA. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010 OI Hudnut, Kenneth/0000-0002-3168-4797; NR 23 TC 16 Z9 16 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 1994 VL 84 IS 3 BP 660 EP 667 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300014 ER PT J AU WALD, DJ HEATON, TH AF WALD, DJ HEATON, TH TI SPATIAL AND TEMPORAL DISTRIBUTION OF SLIP FOR THE 1992 LANDERS, CALIFORNIA, EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID 28 JUNE 1992; STRONG-MOTION; RUPTURE HISTORY; 7.3 LANDERS; INVERSION; SEQUENCE; RECORDS; FAULTS AB We have determined a source rupture model for the 1992 Landers earthquake (M(W) 7.2) compatible with multiple data sets, spanning a frequency range from zero to 0.5 Hz. Geodetic survey displacements, near-field and regional strong motions, broadband teleseismic waveforms, and surface offset measurements have been used explicitly to constrain both the spatial and temporal slip variations along the model fault surface. Our fault parameterization involves a variable-slip, multiple-segment, finite-fault model which treats the diverse data sets in a self-consistent manner, allowing them to be inverted both independently and in unison. The high-quality data available for the Landers earthquake provide an unprecedented opportunity for direct comparison of rupture models determined from independent data sets that sample both a wide frequency range and a diverse spatial station orientation with respect to the earthquake slip and radiation pattern. In all models, consistent features include the following: (1) similar overall dislocation patterns and amplitudes with seismic moments of 7 to 8 x 10(26) dyne-cm (seismic potency of 2.3 to 2.7 km3); (2) very heterogeneous, unilateral strike slip distributed over a fault length of 65 km and over a width of at least 15 km, though slip is limited to shallower regions in some areas; (3) a total rupture duration of 24 sec and an average rupture velocity of 2.7 km/sec; and (4) substantial variations of slip with depth relative to measured surface offsets. The extended rupture length and duration of the Landers earthquake also allowed imaging of the propagating rupture front with better resolution than for those of prior shorter-duration, strike-slip events. Our imaging allows visualization of the rupture evolution, including local differences in slip durations and variations in rupture velocity. Rupture velocity decreases markedly at shallow depths, as well as near regions of slip transfer from one fault segment to the next, as rupture propagates northwestward along the multiply segmented fault length. The rupture front slows as it reaches the northern limit of the Johnson Valley/Landers faults where slip is transferred to the southern Homestead Valley fault; an abrupt acceleration is apparent following the transfer. This process is repeated, and is more pronounced, as slip is again passed from the northern Homestead Valley fault to the Emerson fault. Although the largest surface offsets were observed at the northern end of the rupture, our modeling indicates that substantial rupture was also relatively shallow (less than 10 km) in this region. RP WALD, DJ (reprint author), US GEOL SURVEY,PASADENA,CA 91106, USA. OI Wald, David/0000-0002-1454-4514 NR 34 TC 494 Z9 515 U1 3 U2 20 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 1994 VL 84 IS 3 BP 668 EP 691 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300015 ER PT J AU ABERCROMBIE, R MORI, J AF ABERCROMBIE, R MORI, J TI LOCAL OBSERVATIONS OF THE ONSET OF A LARGE EARTHQUAKE - 28 JUNE 1992 LANDERS, CALIFORNIA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID RUPTURE PROPAGATION; SEQUENCE; STRESS; MODEL; ARRAY; ZONE AB The Landers earthquake (M(w) 7.3) of 28 June 1992 had a very emergent onset. The first large amplitude arrivals are delayed by about 3 sec with respect to the origin time, and are preceded by smaller-scale slip. Other large earthquakes have been observed to have similar emergent onsets, but the Landers event is one of the first to be well recorded on nearby stations. We used these recordings to investigate the spatial relationship between the hypocenter and the onset of the large energy release, and to determine the slip function of the 3-sec nucleation process. Relative location of the onset of the large energy release with respect to the initial hypocenter indicates its source was between 1 and 4 km north of the hypocenter and delayed by approximately 2.5 sec. Three-station array analysis of the P wave shows that the large amplitude onset arrives with a faster apparent velocity compared to the first arrivals, indicating that the large amplitude source was several kilometers deeper than the initial onset. An M(L) 2.8 foreshock, located close to the hypocenter, was used as an empirical Green's function to correct for path and site effects from the first 3 sec of the mainshock seismogram. The resultant deconvolution produced a slip function that showed two subevents preceding the main energy release, an M(w) 4.4 followed by an M(w) 5.6. These subevents do not appear anomalous in comparison to simple moderate-sized earthquakes, suggesting that they were normal events which just triggered or grew into a much larger earthquake. If small and moderate-sized earthquakes commonly ''detonate'' much larger events, this implies that the dynamic stresses during earthquake rupture are at least as important as long-term static stresses in causing earthquakes, and the prospects of reliable earthquake prediction from premonitory phenomena are not improved. C1 US GEOL SURVEY, PASADENA, CA 91106 USA. RP UNIV SO CALIF, DEPT GEOL SCI, LOS ANGELES, CA 90089 USA. NR 35 TC 66 Z9 67 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 1994 VL 84 IS 3 BP 725 EP 734 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300018 ER PT J AU HOUGH, SE BEN-ZION, Y LEARY, P AF HOUGH, SE BEN-ZION, Y LEARY, P TI FAULT-ZONE WAVES OBSERVED AT THE SOUTHERN JOSHUA-TREE EARTHQUAKE RUPTURE ZONE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID AFTERSHOCKS AB Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of: (1) emergent P arrivals prior to and opposite in polarity to the impulsive direct phase; these arrivals can be modeled as headwaves indicative of a transfault velocity contrast; (2) spectral peaks in the S wave train that can be interpreted as internally reflected, low-velocity fault-zone wave energy; and (3) spatial selectivity of event-station pairs at which these data are observed, suggesting a long, narrow geologic structure. The observed waveforms are modeled using the analytical solution of Ben-Zion and Aki (1990) for a plane-parallel layered fault-zone structure. Synthetic waveform fits to the observed data indicate the presence of NS-trending vertical fault-zone layers characterized by a thickness of 50 to 100 m, a velocity decrease of 10 to 15% relative to the surrounding rock, and a P-wave quality factor in the range 25 to 50. C1 HARVARD UNIV, CAMBRIDGE, MA 02138 USA. UNIV EDINBURGH, EDINBURGH EH8 9YL, MIDLOTHIAN, SCOTLAND. RP HOUGH, SE (reprint author), US GEOL SURVEY, PASADENA, CA 91106 USA. NR 12 TC 51 Z9 51 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 JUN PY 1994 VL 84 IS 3 BP 761 EP 767 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300021 ER PT J AU JOHNSTON, MJS MUELLER, RJ SASAI, Y AF JOHNSTON, MJS MUELLER, RJ SASAI, Y TI MAGNETIC-FIELD OBSERVATIONS IN THE NEAR-FIELD THE 28 JUNE 1992 M(W) 7.3 LANDERS, CALIFORNIA, EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID ACTIVE FAULTS; LOMA-PRIETA; HOLLISTER AB Recent reports suggest that large magnetic field changes occur prior to, and during, large earthquakes. Two continuously operating proton magnetometers, LSBM and OCHM, at distances of 17.3 and 24.2 km, respectively, from the epicenter of the 28 June 1992 M(w) 7.3 Landers earthquake, recorded data through the earthquake and its aftershocks. These two stations are part of a differentially connected array of proton magnetometers that has been operated along the San Andreas fault since 1976. The instruments have a sensitivity of 0.25 nT or better and transmit data every 10 min through the GOES satellite to the USGS headquarters in Menlo Park, California. Seismomagnetic offsets of -1.2 +/- 0.6 and -0.7 +/- 0.7 nT were observed at these sites. In comparison, offsets of -0.3 +/- 0.2 and -1.3 +/- 0.2 nT were observed during the 8 July 1986 M(L) 5.9 North Palm Springs earthquake, which occurred directly beneath the OCHM magnetometer site. The observations are generally consistent with seismomagnetic models of the earthquake, in which fault geometry and slip have the same form as that determined by either inversion of the seismic data or inversion of geodetically determined ground displacements produced by the earthquake. In these models, right-lateral rupture occurs on connected fault segments in a homogeneous medium with average magnetization of 2 A/m. The fault-slip distribution has roughly the same form as the observed surface rupture, and the total moment release is 1.1 x 10(20) Nm. There is no indication of diffusion-like character to the magnetic field offsets that might indicate these effects result from fluid flow phenomena. It thus seems unlikely that these earthquake-generated offsets and those produced by the North Palm Springs earthquake were generated by electrokinetic effects. Also, there are no indications of enhanced low-frequency magnetic noise before the earthquake at frequencies below 0.001 Hz. C1 UNIV TOKYO,EARTHQUAKE RES INST,TOKYO 113,JAPAN. RP JOHNSTON, MJS (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 28 TC 43 Z9 49 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 1994 VL 84 IS 3 BP 792 EP 798 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300024 ER PT J AU JOHNSTON, MJS LINDE, AT AGNEW, DC AF JOHNSTON, MJS LINDE, AT AGNEW, DC TI CONTINUOUS BOREHOLE STRAIN IN THE SAN-ANDREAS FAULT ZONE BEFORE, DURING, AND AFTER THE 28 JUNE 1992, M(W)7.3 LANDERS, CALIFORNIA, EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN-CALIFORNIA; DEFORMATION; SEQUENCE; RUPTURE; TILTS; SHEAR AB High-precision strain was observed with a borehole dilational strainmeter in the Devil's Punchbowl during the 11:58 UT 28 June 1992 M(w) 7.3 Landers earthquake and the large Big Bear aftershock (M(w) 6.3). The strainmeter is installed at a depth of 176 m in the fault zone approximately midway between the surface traces of the San Andreas and Punchbowl faults and is about 100 km from the 85-km-long Landers rupture. We have questioned whether unusual amplified strains indicating precursive slip or high fault compliance occurred on the faults ruptured by the Landers earthquake, or in the San Andreas fault zone before and during the earthquake, whether static offsets for both the Landers and Big Bear earthquakes agree with expectations from geodetic and seismologic models of the ruptures and with observations from a nearby two-color geodimeter network, and whether postseismic behavior indicated continued slip on the Landers rupture or local triggered slip on the San Andreas. We show that the strain observed during the earthquake at this instrument shows no apparent amplification effects. There are no indications of precursive strain in these strain data due to either local slip on the San Andreas or precursive slip on the eventual Landers rupture. The observations are generally consistent with models of the earthquake in which fault geometry and slip have the same form as that determined by either inversion of the seismic data or inversion of geodetically determined ground displacements produced by the earthquake. Finally, there are some indications of minor postseismic behavior, particularly during the month following the earthquake. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,IGPP,LA JOLLA,CA 92093. CARNEGIE INST WASHINGTON,DEPT TERR MAGNET,WASHINGTON,DC 20015. RP JOHNSTON, MJS (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 31 TC 29 Z9 30 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 JUN PY 1994 VL 84 IS 3 BP 799 EP 805 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300025 ER PT J AU BODIN, P BILHAM, R BEHR, J GOMBERG, J HUDNUT, KW AF BODIN, P BILHAM, R BEHR, J GOMBERG, J HUDNUT, KW TI SLIP TRIGGERED ON SOUTHERN CALIFORNIA FAULTS BY THE 1992 JOSHUA-TREE, LANDERS, AND BIG-BEAR EARTHQUAKES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; SUPERSTITION HILLS FAULT; PALM-SPRINGS EARTHQUAKE; APRIL AB Five out of six functioning creepmeters on southern California faults recorded slip triggered at the time of some or all of the three largest events of the 1992 Landers earthquake sequence. Digital creep data indicate that dextral slip was triggered within 1 min of each mainshock and that maximum slip velocities occurred 2 to 3 min later. The duration of triggered slip events ranged from a few hours to several weeks. We note that triggered slip occurs commonly on faults that exhibit fault creep. To account for the observation that slip can be triggered repeatedly on a fault, we propose that the amplitude of triggered slip may be proportional to the depth of slip in the creep event and to the available near-surface tectonic strain that would otherwise eventually be released as fault creep. We advance the notion that seismic surface waves, perhaps amplified by sediments, generate transient local conditions that favor the release of tectonic strain to varying depths. Synthetic strain seismograms are presented that suggest increased pore pressure during periods of fault-normal contraction may be responsible for triggered slip, since maximum dextral shear strain transients correspond to times of maximum fault-normal contraction. C1 UNIV COLORADO,CIRES,BOULDER,CO 80309. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. US GEOL SURVEY,PASADENA,CA 91106. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010; OI Hudnut, Kenneth/0000-0002-3168-4797; Bilham, Roger/0000-0002-5547-4102 NR 31 TC 40 Z9 40 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 JUN PY 1994 VL 84 IS 3 BP 806 EP 816 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300026 ER PT J AU HOUGH, SE AF HOUGH, SE TI SOUTHERN SURFACE RUPTURE ASSOCIATED WITH THE M-7.3 1992 LANDERS, CALIFORNIA, EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SUPERSTITION HILLS EARTHQUAKE; SEISMICITY; SEQUENCE; SLIP AB Although most evidence suggests that the 28 June 1992 M 7.3 Landers earthquake ruptured unilaterally north, significant surface rupture was mapped on the Eureka Peak and Burnt Mountain faults, to the south of the Landers epicenter. An eyewitness account reports that surface rupture occurred on the northern Eureka Peak fault within approximately 35 sec of the mainshock initiation. Array analysis of the Landers mainshock provides evidence in support of this report; a significant southern subevent in the early mainshock coda. I also analyze dense array recordings of a M 5.6 aftershock that occurred 3 min after the mainshock at 34-degrees 7.65'N, 116-degrees 23.82'W and show that there is strong evidence that this event was also associated with significant rupture on the Eureka Peak fault. This analysis thus suggests that the Eureka Peak fault rupture was not caused by direct bilateral mainshock rupture but instead was initially triggered less than a minute after the mainshock and reruptured by the M 5.6 aftershock. Results for the evolution of the Landers sequence suggest that mainshock subevents may in some cases be accurately described as aftershocks (i.e., disjoint triggered events) that occur within the duration of mainshock strong ground motion. RP US GEOL SURVEY, PASADENA, CA 91106 USA. NR 28 TC 5 Z9 5 U1 0 U2 1 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 1994 VL 84 IS 3 BP 817 EP 825 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300027 ER PT J AU BODIN, P GOMBERG, J AF BODIN, P GOMBERG, J TI TRIGGERED SEISMICITY AND DEFORMATION BETWEEN THE LANDERS, CALIFORNIA, AND LITTLE-SKULL-MOUNTAIN, NEVADA, EARTHQUAKES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; EASTERN CALIFORNIA; MOJAVE-DESERT; GREAT-BASIN; SHEAR ZONE; SLIP AB This article presents evidence for the channeling of strain energy released by the M(s) = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in seismicity levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the M(s) = 5.4 Little Skull Mountain (LSM), Nevada, earthquake. We evaluate the completeness of regional seismicity catalogs during this period and find that the continuity of post-Landers strain release within the ECSZ is even more pronounced than is evident from the catalog data. We hypothesize that regional-scale connectivity of faults within the ECSZ and LSM region is a critical ingredient in the unprecedented scale and distribution of remotely triggered earthquakes and geodetically manifest strain changes that followed the Landers earthquake. The viability of static strain changes as triggering agents is tested using numerical models. Modeling results illustrate that regional-scale fault connectivity can increase the static strain changes by approximately an order of magnitude at distances of at least 280 km, the distance between the Landers and LSM epicenters. This is possible for models that include both a network of connected faults that slip ''sympathetically'' and realistic levels of tectonic prestrain. Alternatively, if dynamic strains are a more significant triggering agent than static strains, ECSZ structure may still be important in determining the distribution of triggered seismic and aseismic deformation. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 34 TC 53 Z9 55 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 JUN PY 1994 VL 84 IS 3 BP 835 EP 843 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300029 ER PT J AU GOMBERG, J BODIN, P AF GOMBERG, J BODIN, P TI TRIGGERING OF THE MS = 5.4 LITTLE SKULL MOUNTAIN, NEVADA, EARTHQUAKE WITH DYNAMIC STRAINS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID CALIFORNIA; LANDERS; QUARTZ AB We have developed an approach to test the viability of dynamic strains as a triggering mechanism by quantifying the dynamic strain tensor at seismogenic depths. We focus on the dynamic strains at the hypocenter of the M(s) = 5.4 Little Skull Mountain (LSM), Nevada, earthquake. This event is noteworthy because it is the largest earthquake demonstrably triggered at remote distances (approximately 280 km) by the M(s) = 7.4 Landers, California, earthquake and because of its ambiguous association with magmatic activity. Our analysis shows that, if dynamic strains initiate remote triggering, the orientation and modes of faulting most favorable for being triggered by a given strain transient change with depth. The geometry of the most probable LSM fault plane was favorably oriented with respect to the geometry of the dynamic strain tensor. We estimate that the magnitude of the peak dynamic strains at the hypocentral depth of the LSM earthquake were approximately 4 mustrain (approximately .2 MPa) which are approximately 50% smaller than those estimated from velocity seismograms recorded at the surface. We suggest that these strains are too small to cause Mohr-Coulomb style failure unless the fault was prestrained to near failure levels, the fault was exceptionally weak, and/or the dynamic strains trigger other processes that lead to failure. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 27 TC 73 Z9 77 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 JUN PY 1994 VL 84 IS 3 BP 844 EP 853 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300030 ER PT J AU JONES, LM AF JONES, LM TI FORESHOCKS, AFTERSHOCKS, AND EARTHQUAKE PROBABILITIES - ACCOUNTING FOR THE LANDERS EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN-CALIFORNIA; STRESS; SEQUENCE; HAZARD; APRIL AB The equation to determine the probability that an earthquake occurring near a major fault will be a foreshock to a mainshock on that fault is modified to include the case of aftershocks to a previous earthquake occurring near the fault. The addition of aftershocks to the background seismicity makes its less probable that an earthquake will be a foreshock, because nonforeshocks have become more common. As the aftershocks decay with time, the probability that an earthquake will be a foreshock increases. However, fault interactions between the first mainshock and the major fault can increase the long-term probability of a characteristic earthquake on that fault, which will, in tum, increase the probability that an event is a foreshock, compensating for the decrease caused by the aftershocks. RP JONES, LM (reprint author), US GEOL SURVEY,PASADENA,CA 91106, USA. NR 12 TC 20 Z9 21 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 JUN PY 1994 VL 84 IS 3 BP 892 EP 899 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300033 ER PT J AU KING, GCP STEIN, RS LIN, J AF KING, GCP STEIN, RS LIN, J TI STATIC STRESS CHANGES AND THE TRIGGERING OF EARTHQUAKES SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; SUPERSTITION HILLS EARTHQUAKE; SOUTHERN-CALIFORNIA; 1992 LANDERS; CAJON-PASS; RECURRENCE INTERVAL; NOVEMBER 1987; JULY 1986; SEQUENCE; DEFORMATION AB To understand whether the 1992 M = 7.4 Landers earthquake changed the proximity to failure on the San Andreas fault system, we examine the general problem of how one earthquake might trigger another. The tendency of rocks to fail in a brittle manner is thought to be a function of both shear and confining stresses, commonly formulated as the Coulomb failure criterion. Here we explore how changes in Coulomb conditions associated with one or more earthquakes may trigger subsequent events. We first consider a Coulomb criterion appropriate for the production of aftershocks, where faults most likely to slip are those optimally orientated for failure as a result of the prevailing regional stress field and the stress change caused by the mainshock. We find that the distribution of aftershocks for the Landers earthquake, as well as for several other moderate events in its vicinity, can be explained by the Coulomb criterion as follows: aftershocks are abundant where the Coulomb stress on optimally orientated faults rose by more than one-half bar, and aftershocks are sparse where the Coulomb stress dropped by a similar amount. Further, we find that several moderate shocks raised the stress at the future Landers epicenter and along much of the Landers rupture zone by about a bar, advancing the Landers shock by 1 to 3 centuries. The Landers rupture, in turn, raised the stress at site of the future M = 6.5 Big Bear aftershock site by 3 bars. The Coulomb stress change on a specified fault is independent of regional stress but depends on the fault geometry, sense of slip, and the coefficient of friction. We use this method to resolve stress changes on the San Andreas and San Jacinto faults imposed by the Landers sequence. Together the Landers and Big Bear earthquakes raised the stress along the San Bernardino segment of the southern San Andreas fault by 2 to 6 bars, hastening the next great earthquake there by about a decade. C1 WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP KING, GCP (reprint author), INST PHYS GLOBE STRASBOURG, F-67084 STRASBOURG, FRANCE. NR 55 TC 1079 Z9 1189 U1 16 U2 95 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1994 VL 84 IS 3 BP 935 EP 953 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NQ993 UT WOS:A1994NQ99300036 ER PT J AU BROWN, LR MOYLE, PB AF BROWN, LR MOYLE, PB TI DISTRIBUTION, ECOLOGY, AND STATUS OF THE FISHES OF THE SAN-JOAQUIN RIVER DRAINAGE, CALIFORNIA SO CALIFORNIA FISH AND GAME LA English DT Article AB In 1985 and 1986 we sampled streams of the San Joaquin River drainage in south-central California. The purposes of the survey were: (i) to see if further declines in native fish populations had occurred since 1970 when they were last surveyed; (ii) to verify the species distributions and species-habitat relationships observed in previous studies; (iii) to verify the species assemblages observed in previous studies; and (iv) to determine the status of the recently described Kern brook lamprey (Lampetra hubbsi). We also reviewed the status of the native fish fauna as compared to pre-European times. Only 11 species of the original fauna of 19 species were found and only 6 of the 11 were common. Hardhead (Mylopharodon conocephalus) and hitch (Lavinia exilicauda) were found in fewer localities than in 1970. The decline in hardhead was associated with an expansion of smallmouth bass (Micropterus dolomieu) populations. Three assemblages of native species were identified, in agreement with earlier studies. A fourth assemblage identified in earlier studies, composed largely of introduced fishes, was divided into two subgroups on the basis of our analysis. Each assemblage of species was associated with a distinct set of habitat characteristics. Populations of Kern brook lamprey were found in the Kaweah, Kings, San Joaquin, and Merced rivers. Lampreys were absent from the lower reaches of the rivers and, except in the Kings River, were only found below major dams. In the Kings River lampreys were captured above and below Pine Flat Reservoir. Because the populations are restricted in range, effectively isolated from one another, and all but one can be affected by reservoir operations, special protection for them is warranted. RP BROWN, LR (reprint author), US GEOL SURVEY,2800 COTTAGE WAY,RM W2234,SACRAMENTO,CA 95825, USA. NR 0 TC 3 Z9 3 U1 0 U2 3 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD SUM PY 1994 VL 79 IS 3 BP 96 EP 114 PG 19 WC Fisheries; Zoology SC Fisheries; Zoology GA NN196 UT WOS:A1994NN19600002 ER PT J AU COPE, WG WIENER, JG STEINGRAEBER, MT ATCHISON, GJ AF COPE, WG WIENER, JG STEINGRAEBER, MT ATCHISON, GJ TI CADMIUM, METAL-BINDING PROTEINS, AND GROWTH IN BLUEGILL (LEPOMIS-MACROCHIRUS) EXPOSED TO CONTAMINATED SEDIMENTS FROM THE UPPER MISSISSIPPI RIVER BASIN SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SALMO-GAIRDNERI RICHARDSON; FRESH-WATER FISH; BROOK TROUT; MEASURING METALLOTHIONEIN; TISSUE DISTRIBUTION; BIOLOGICAL TISSUES; ACCUMULATION; MERCURY; TOXICITY; GILLS AB We exposed juvenile bluegill (Lepomis macrochirus) to similar to 1000 mg.L(-1) of continuously suspended river sediment in a 28-d test with six treatments (randomized block with one sediment-free control and five sediments ranging from 1.3 to 21.4 mu g Cd.g dry weight(-1)). Each treatment had three replicates, each with 25 fish. Growth was reduced by exposure to suspended sediment, probably due to physical effects of sediment on feeding and to toxicity in the treatment with the greatest concentrations of metals. Mean whole-body concentrations of cadmium (0.04-0.14 mu g g wet weight(-1)) were correlated with cadmium concentration in filtered water (8-72 ng.L(-1)), suspended sediment (0.61-16.8 mu g.L(-1)), and bulk sediment. The concentration of hepatic nonthionein cytosolic cadmium (cadmium not bound by metal-binding proteins, MBP) in fish exposed to the two most contaminated sediments exceeded that in controls. The mean concentration of hepatic MBP was correlated with cadmium concentration in filtered water, suspended sediment, bulk sediment, and whole fish. Whole-body cadmium concentration was the most sensitive indicator of cadmium exposure, with lowest observed effect concentrations of 1.9 mu g Cd.L(-1) for suspended sediment and 13 ng Cd.L(-1) for filtered water. Sediment-associated cadmium was less available than waterborne cadmium for uptake by fish. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT ANIM ECOL,AMES,IA 50011. RP COPE, WG (reprint author), US FISH & WILDLIFE SERV,NATL FISHERIES RES CTR,NATL BIOL SURVEY,FIELD RES STN,POB 818,LA CROSSE,WI 54602, USA. NR 68 TC 21 Z9 21 U1 0 U2 3 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 JUN PY 1994 VL 51 IS 6 BP 1356 EP 1367 DI 10.1139/f94-135 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA PG146 UT WOS:A1994PG14600014 ER PT J AU CRONIN, MA HILLS, S BORN, EW PATTON, JC AF CRONIN, MA HILLS, S BORN, EW PATTON, JC TI MITOCHONDRIAL-DNA VARIATION IN ATLANTIC AND PACIFIC WALRUSES SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID SEQUENCE; POPULATIONS; ORGANIZATION; GENETICS; GENOME; TREES AB We used restriction enzyme analysis of polymerase chain reaction amplified mitochondrial DNA to assess genetic differentiation of two subspecies of walruses: Atlantic walruses (Odobenus rosmarus rosmarus) from Greenland and Pacific walruses (O. r. divergens) from the Chukchi Sea. Each subspecies has distinct monophyletic mitochondrial DNA haplotypes. Mitochondrial DNA sequence divergence between Atlantic and Pacific subspecies was 1.0-1.6%. Several haplotypes were observed for each subspecies. Haplotype frequencies varied among sampling locations of Atlantic walruses, suggesting that mitochondrial DNA may be useful for walrus stock identification. C1 US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. GREENLAND FISHERIES RES INST,DK-2200 COPENHAGEN N,DENMARK. LGL ECOL RES ASSOC INC,BRYAN,TX 77801. NR 36 TC 32 Z9 33 U1 0 U2 9 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 1994 VL 72 IS 6 BP 1035 EP 1043 DI 10.1139/z94-140 PG 9 WC Zoology SC Zoology GA PP591 UT WOS:A1994PP59100009 ER PT J AU EVANS, HT POST, JE ROSS, DR NELEN, JA AF EVANS, HT POST, JE ROSS, DR NELEN, JA TI THE CRYSTAL-STRUCTURE AND CRYSTAL-CHEMISTRY OF FERNANDINITE AND CORVUSITE SO CANADIAN MINERALOGIST LA English DT Article DE CORVUSITE; FERNANDINITE; RIETVELD ANALYSIS; STRACZEKITE-TYPE STRUCTURE; VANADIUM BRONZE AB Using type material of fernandinite (Ca,Na,K)xV8O20.4H2O) from Minasragra, Peru, and corvusite (NaCa,K)xV8O20.4H2O) from the Jack Claim, La Sal Mountains, Utah, the properties and crystal chemistry of these minerals have been determined by Rietveld analysis of the powder X-ray-diffraction patterns. The associated unit-cell parameters in space group C2/m (monoclinic) for fernandinite [corvusite] are: a 11.680(2) [11.706(4)] angstrom, b 3.6537(4) [3.644(1)] angstrom, c 11.023(2) [11.10(1)] angstrom, beta 105.00(2) [103.46(7)]degrees. The crystal structure of both species is isotypic with the V2O5-type layer first found for delta-Ag0.68V2O5; it consists of chains of VO6 octahedra linked by opposite comers (parallel to b) condensed by edge-sharing to form the layer. The vanadium has average valence 4.8, and the resulting layer-charge is balanced by varying amounts of Ca, Na, and K in the interlayer region (x in the above formulas varies from 0.9 to 1.2), accompanied by labile water (amount depending on humidity and heat). This study has confirmed the validity of fernandinite as a unique mineral species. It is closely related to corvusite, from which it is distinguished on the basis of the dominant interlayer cation: Ca for fernandinite, Na for corvusite. C1 SMITHSONIAN INST,DEPT MINERAL SCI,WASHINGTON,DC 20560. RP EVANS, HT (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 22 TC 7 Z9 7 U1 2 U2 3 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD JUN PY 1994 VL 32 BP 339 EP 351 PN 2 PG 13 WC Mineralogy SC Mineralogy GA NX349 UT WOS:A1994NX34900009 ER PT J AU GRAUCH, RI LINDAHL, I EVANS, HT BURT, DM FITZPATRICK, JJ FOORD, EE GRAFF, PR HYSINGJORD, J AF GRAUCH, RI LINDAHL, I EVANS, HT BURT, DM FITZPATRICK, JJ FOORD, EE GRAFF, PR HYSINGJORD, J TI HOGTUVAITE, A NEW BERYLLIAN MEMBER OF THE AENIGMATITE GROUP FROM NORWAY, WITH NEW X-RAY DATA ON AENIGMATITE SO CANADIAN MINERALOGIST LA English DT Article DE HOGTUVAITE; NEW MINERAL; COMPOSITION; X-RAY DATA; AENIGMATITE; NORWAY ID CRYSTAL AB Hogtuvaite, essentially (Ca, Na)2 (Fe2+, Fe3+, Ti, Mg, Mn, Sn)6 (Si, Be, Al)6 O20, is a new beryllian member of the aenigmatite group that was discovered in Nordland County, Norway. It is a metamorphic mineral, hosted by Proterozoic granitic gneisses and mafic pegmatites of metamorphic origin. Compositional variations within and between gneiss-hosted samples of hogtuvaite are minimal; however, pegmatite-hosted samples of hogtuvaite are significantly different, containing less Al and Sn, and more Ti and Mn, than those from the gneisses. The composition of type hogtuvaite (in wt.%) is CaO 10.44, Na2O 1.52, FeO 28.06, Fe2O3 19.03, TiO2 2.77, MgO 0.42, MnO 0.27, SnO2 0.53, SiO2 31.60, BeO 2.65, Al2O3 2.64. Hogtuvaite forms black, elongate, poikiloblastic crystals. It has a dark green streak, an uneven fracture, two good cleavage directions, and a nonmetallic subadamantine luster. It is nonmagnetic, is not fluorescent, and does not react to most common acids and bases. However, it does dissolve slowly in cold hydrofluoric acid. Its measured density is 3.85 g/cm3, and the calculated density is 3.98 g/cm3. The mineral is opaque to subtransparent, biaxial negative (?) with a large 2V, strongly pleochroic (bronze to green) and has alpha' 1.78 and gamma' 1.82. It is triclinic (pseudo-monoclinic), space group P1BAR, with a 10.317(1), b 10.724(1) c 8.855(1) angstrom, alpha 105.77(1)degrees, beta 96.21(1)degrees, gamma 124.77(1)degrees, V 730.4(1) angstrom3, and Z = 2. All samples are intensely polysynthetically twinned. The strongest seven X-ray powder-diffraction lines [d in angstrom(1)(hkl)] are 2.5293(100)(420BAR), 8.048(90)(010), 2.0979(63)(251BAR), 2.9247(59)(031BAR), 2.6761(48)(241BAR), 2.0747(47)(411BAR) and 3.125(46)(021). A new and uniquely indexed set of X-ray powder diffraction data for aenigmatite is presented. The name hogtuvaite is inspired by the highest peak near die type locality. C1 NORGES GEOL UNDERSOKELSE,N-7002 TRONDHEIM,NORWAY. US GEOL SURVEY,RESTON,VA 22092. ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85281. RP GRAUCH, RI (reprint author), US GEOL SURVEY,973 DENVER FED CTR,DENVER,CO 80225, USA. NR 23 TC 17 Z9 18 U1 1 U2 4 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD JUN PY 1994 VL 32 BP 439 EP 448 PN 2 PG 10 WC Mineralogy SC Mineralogy GA NX349 UT WOS:A1994NX34900020 ER PT J AU DIMES, LE HAARD, NF DONG, FM RASCO, BA FORSTER, IP FAIRGRIEVE, WT ARNDT, R HARDY, RW BARROWS, FT HIGGS, DA AF DIMES, LE HAARD, NF DONG, FM RASCO, BA FORSTER, IP FAIRGRIEVE, WT ARNDT, R HARDY, RW BARROWS, FT HIGGS, DA TI ESTIMATION OF PROTEIN DIGESTIBILITY .2. IN-VITRO ASSAY OF PROTEIN IN SALMONID FEEDS SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY LA English DT Article DE PROTEIN DIGESTIBILITY; SALMONID FEEDS ID TROUT; GAIRDNERI AB The in vitro digestibility of protein in various salmonid feeds was determined by pH-stat using enzyme fractions from trout pyloric ceca. Data were compared with in vivo digestibility and growth of fish by linear regression analysis. Results indicated that there were good agreements between the degree of hydrolysis of most feed samples and growth of fish. The pH-stat method is not suited for feed samples that have been partially hydrolyzed during their preparation. C1 UNIV WASHINGTON,SCH FISHERIES,SEATTLE,WA 98105. NATL MARINE FISHERIES SERV,SEATTLE,WA 98105. FISHERIES & OCEANS CANADA,W VANCOUVER LAB,W VANCOUVER V7V 1N6,BC,CANADA. US FISH & WILDLIFE SERV,CTR FISH TECHNOL,BOZEMAN,MT 59715. RP DIMES, LE (reprint author), UNIV CALIF DAVIS,INST MARINE RESOURCES,DAVIS,CA 95616, USA. RI Forster, Ian/E-8098-2010 OI Forster, Ian/0000-0002-4256-4432 NR 16 TC 32 Z9 32 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0300-9629 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Physiol. PD JUN-JUL PY 1994 VL 108 IS 2-3 BP 363 EP 370 DI 10.1016/0300-9629(94)90107-4 PG 8 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA NY983 UT WOS:A1994NY98300029 ER EF