Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin
N. J. Godfrey, B. C. Beaudoin, S.L. Klemperer, A. Levander, J. Luetgert, A. Meltzer, Walter D. Mooney, A. Trehu
1997, Geological Society of America Bulletin (109) 1536-1562
The nature of the Great Valley basement, whether oceanic or continental, has long been a source of controversy. A velocity model (derived from a 200-km-long east-west reflection-refraction profile collected south of the Mendocino triple junction, northern California, in 1993), further constrained by density and magnetic models, reveals an ophiolite underlying...
Petrography and geochemistry of selected lignite beds in the Gibbons Creek mine (Manning Formation, Jackson Group, Paleocene) of east-central Texas
Peter D. Warwick, Sharon S. Crowley, Leslie F. Ruppert, James Pontolillo
1997, International Journal of Coal Geology (34) 307-326
This study examined the petrographic and geochemical characteristics of two lignite beds (3500 and 4500 beds, Manning Formation, Jackson Group, Eocene) that are mined at the Gibbons Creek mine in east-central Texas. The purpose of the study was to identify the relations among sample ash yield, coal petrography, and trace-element...
Soluble trace elements and total mercury in Arctic Alaskan snow
E. Snyder-Conn, John R. Garbarino, Gerald L. Hoffman, A. Oelkers
1997, Arctic (50) 201-215
Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites...
Climatic controls of western U.S. glaciers at the last glacial maximum
S. W. Hostetler, P.U. Clark
1997, Quaternary Science Reviews (16) 505-511
We use a nested atmospheric modeling strategy to simulate precipitation and temperature of the western United States 18,000 years ago (18 ka). The high resolution of the nested model allows us to isolate the regional structure of summer temperature and winter precipitation that is crucial to determination of the net...
Coal quality trends and distribution of potentially hazardous trace elements in eastern Kentucky coals
C.F. Eble, J.C. Hower
1997, Fuel (76) 711-715
Coal in the Eastern Kentucky coalfield has been, and continues to be, a valuable energy resource, especially for the electric utility industry. However, Federal mandates in Titles III and IV of the Clean Air Act Amendments of 1990 have placed increasingly stringent demands on the type and grade of coal...
The Chesapeake Bay bolide impact: A convulsive event in Atlantic Coastal Plain evolution
C. Wylie Poag
1997, Sedimentary Geology (108) 45-90
Until recently, Cenozoic evolution of the Atlantic Coastal Plain has been viewed as a subcyclical continuum of deposition and erosion. Marine transgressions alternated with regressions on a slowly subsiding passive continental margin, their orderly succession modified mainly by isostatic adjustments, occasional Appalachian tectonism, and paleoclimatic change. This passive scenario was...
Late Cenozoic history and slip rates of the Fish Lake Valley, Emigrant Peak, and Deep Springs fault zones, Nevada and California
M.C. Reheis, T. L. Sawyer
1997, Geological Society of America Bulletin (109) 280-299
Several well-dated stratigraphic markers permit detailed assessment of the temporal and spatial variation in slip rates along the interconnected faults of the Fish Lake Valley, Emigrant Peak, and Deep Springs fault zones in west-central Nevada and east-central California. Right-lateral motion on the Fish Lake Valley fault zone apparently began ca....
Rapid extension in an Eocene volcanic arc: Structure and paleogeography of an intra-arc half graben in central Idaho
S. U. Janecke, B.F. Hammond, L.W. Snee, J. W. Geissman
1997, Geological Society of America Bulletin (109) 253-267
A study of extension, volcanism, and sedimentation in the middle Eocene Panther Creek half graben in central Idaho shows that it formed rapidly during an episode of voluminous volcanism. The east-southeast-tilted Panther Creek half graben developed across the northeast edge of the largest cauldron complex of the Challis volcanic field...
Changes in breeding bird populations in North Dakota: 1967 to 1992-93
L.D. Igl, Douglas H. Johnson
1997, The Auk (114) 74-92
We compared breeding bird populations in North Dakota using surveys conducted in 1967 and 1992-93. In decreasing order, the five most frequently occurring species were Horned Lark (Eremophila alpestris), Brown-headed Cowbird (Molothrus ater), Western Meadowlark (Sturnella neglecta), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Kingbird (Tyrannus tyrannus). The five most abundant...
Description and epizootiology of Babesia poelea n. sp. in brown boobies (Sula leucogaster (Boddaert)) on Sand Island, Johnston Atoll, Central Pacific
Thierry M. Work, Robert Rameyer
1997, Journal of Parasitology (83) 734-738
We describe a new species of piroplasm from brown boobies (Sula leucogaster) on Sand Island, Johnston Atoll National Wildlife Refuge, central Pacific. Mean parasitemia in adults and chicks was less than 1%, with the parasitemia in chicks significantly greater than in adults. There was no significant relation between the age...
Correlation of Upper Cretaceous strata from Lima Peaks area to Madison Range, southwestern Montana and southeastern Idaho, USA
T. S. Dyman, R. G. Tysdal, W. J. Perry Jr., J. D. Obradovich, J. C. Haley, D. J. Nichols
1997, Cretaceous Research (18) 751-766
An40Ar/39Ar age of 85.81 Ma±0.22 my was obtained on sanidine from a volcanic procellanite bed near the top of the 2135+m-thick Upper Cretaceous Frontier Formation in the Lima Peaks area of southwestern Montana. This early Santonian age, combined with previously determined age data including a palynological age of Cenomanian for...
Hazard assessment of inorganics, individually and in mixtures, to two endangered fish in the San Juan River, New Mexico
Steven J. Hamilton, Kevin J. Buhl
1997, Environmental Toxicology (12) 195-209
Acute toxicity tests were conducted for 96 h with larval Colorado squawfish (Ptychocheilus lucius) and razorback sucker (Xyrauchen texanus) in a reconstituted water quality simulating the San Juan River near Shiprock, New Mexico, to determine biological effect concentrations. Tests were conducted with arsenate, copper, selenate, selenite, zinc, and five mixtures...
NDVI, C3 and C4 production, and distributions in Great Plains grassland land cover classes
L.L. Tieszen, Bradley C. Reed, Norman B. Bliss, Bruce K. Wylie, Benjamin D. DeJong
1997, Ecological Applications (7) 59-78
The distributions of C3 and C4 grasses were used to interpret the distribution, seasonal performance, and potential production of grasslands in the Great Plains of North America. Thirteen major grassland seasonal land cover classes were studied with data from three distinct sources. Normalized Difference Vegetation Index (NDVI) data derived from...
Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics
H. Fuenzalida, L. Rivera, H. Haessler, D. Legrand, H. Philip, L. Dorbath, D. McCormack, S. Arefiev, C. Langer, A. Cisternas
1997, Geophysical Journal International (130) 29-46
The Racha-Dzhava earthquake (Ms=7.0) that occurred on 1991 April 29 at 09:12:48.1 GMT in the southern border of the Great Caucasus is the biggest event ever recorded in the region, stronger than the Spitak earthquake (Ms=6.9) of 1988. A field expedition to the epicentral area was organised and a...
Upper Mississippi embayment shallow seismic velocities measured in situ
Huaibao P. Liu, Y. Hu, J. Dorman, T.-S. Chang, J.-M. Chiu
1997, Engineering Geology (46) 313-330
Vertical seismic compressional- and shear-wave (P- and S-wave) profiles were collected from three shallow boreholes in sediment of the upper Mississippi embayment. The site of the 60-m hole at Shelby Forest, Tennessee, is on bluffs forming the eastern edge of the Mississippi alluvial plain. The bluffs are composed of Pleistocene...
Jonah field, Sublette County, Wyoming: Gas production from overpressured Upper Cretaceous Lance sandstones of the Green River basin
Scott L. Montgomery, J. W. Robinson
1997, American Association of Petroleum Geologists Bulletin (81) 1049-1062
Jonah field, located in the northwestern Green River basin, Wyoming, produces gas from overpressured fluvial channel sandstones of the Upper Cretaceous Lance Formation. Reservoirs exist in isolated and amalgamated channel facies 10-100 ft (3-30 m) thick and 150-4000 ft (45-1210 m) wide, deposited by meandering and braided streams. Compositional and...
Unnatural isotopic composition of lithium reagents
H. P. Qi, Tyler B. Coplen, Q. Zh Wang, Y. #NAME? Wang
1997, Analytical Chemistry (69) 4076-4078
Isotopic analysis of 39 lithium reagents from several manufacturers indicates that seven were artificially depleted in 6Li significantly in excess of the variation found in terrestrial materials. The atomic weight of lithium in analyzed reagents ranged from 6.939 to 6.996, and δ7Li, reported relative to L-SVEC lithium carbonate, ranged from −11...
Variable deep structure of a midcontinent fault and fold zone from seismic reflection: La Salle deformation belt, Illinois basin
J.H. McBride
1997, Geological Society of America Bulletin (109) 1502-1513
Deformation within the United States midcontinent is frequently expressed as quasilinear zones of faulting and folding, such as the La Salle deformation belt, a northwest-trending series of folds cutting through the center of the Illinois basin. Seismic reflection profiles over the southern La...
Variation in thermal tolerance and routine metabolism among spring- and stream dwelling freshwater sculpins (Teleostei: Cottidae) of the southeastern United States
S. J. Walsh, D. C. Haney, C. M. Timmerman
1997, Ecology of Freshwater Fish (6) 84-94
Evolutionary theory predicts that some aquatic organisms may adapt by directional selection to limiting physical environmental conditions, yet empirical data are conflicting. We sought to test the assumption that sculpins (family Cottidae) inhabiting thermally stable springs of the southeastern United States differ in temperature tolerance and metabolism from populations inhabiting...
Deep-coal potential in the Appalachian Coal Basin, USA: The Kentucky model
D. C. Haney, D.R. Chesnut Jr.
1997, Prace - Panstwowego Instytutu Geologicznego 336-337
The Eastern Kentucky Coal Field is located in the Appalachian Basin of the United States and occupies an area of approximately 15,000 square kilometers. The coal beds range from a few centimeters to several meters in thickness and consist of high-grade bituminous coal. Currently the amount of coal mined by...
Primitive magmas at five Cascade volcanic fields: Melts from hot, heterogeneous sub-arc mantle
C. R. Bacon, P. E. Bruggman, R.L. Christiansen, M.A. Clynne, J.M. Donnelly-Nolan, W. Hildreth
1997, Canadian Mineralogist (35) 397-423
Major and trace element concentrations, including REE by isotope dilution, and Sr, Nd, Pb, and O isotope ratios have been determined for 38 mafic lavas from the Mount Adams, Crater Lake, Mount Shasta, Medicine Lake, and Lassen volcanic fields, in the Cascade arc, northwestern part of the United States. Many...
Effect of wave-enhanced bottom friction on storm-driven circulation in Massachusetts Bay
R. P. Signell, J. H. List
1997, Journal of Waterway, Port, Coastal and Ocean Engineering (123) 233-239
Massachusetts Bay is a shallow (35 m average depth) semienclosed embayment, roughly 100 ?? 50 km, which opens into the Gulf of Maine at its eastern boundary. Surface waves associated with winter storm winds from the northeast cause large sediment resuspension events, and wave and circulation fields during these events...
14C ages and activity for the past 50 ka at Volcán Galeras, Colombia
N.G. Banks, V.M.L. Calvache, S.N. Williams
1997, Journal of Volcanology and Geothermal Research (77) 39-55
Volcán Galeras is the southernmost Colombian volcano with well-recorded historic activity. The volcano is part of a large and complex volcanic center upon which 400,000 people live. Historic activity has centered on a small-volume cone inside the youngest of several large amphitheaters that breach the west flank of the volcano,...
Nested taxa-area curves for eastern United States floras
J. P. Bennett
1997, Rhodora (99) 241-251
The slopes of log-log species-area curves have been studied extensively and found to be influenced by the range of areas under study. Two such studies of eastern United States floras have yielded species-area curve slopes which differ by more than 100%: 0.251 and 0.113. The first slope may be too...
Ground Water Atlas of the United States: Segment 11, Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, Virginia, West Virginia
Henry Trapp Jr., Marilee A. Horn
1997, Hydrologic Atlas 730-L
Segment 11 consists of the States of Delaware, Maryland, New Jersey, North Carolina, West Virginia, and the Commonwealths of Pennsylvania and Virginia. All but West Virginia border on the Atlantic Ocean or tidewater. Pennsylvania also borders on Lake Erie. Small parts of northwestern and north-central Pennsylvania drain to Lake Erie...
