Crustal velocities near Coalinga, California, modeled from a combined earthquake/explosion refraction profile
N. Macgregor-Scott, A. Walter
1988, Bulletin of the Seismological Society of America (78) 1475-1490
Crustal velocity structure for the region near Coalinga, California, has been derived from both earthquake and explosion seismic phase data recorded along a NW-SE seismic-refraction profile on the western flank of the Great Valley east of the Diablo Range. Comparison of the two data sets reveals P-wave phases in common...
Trends in lead concentrations in major U.S. rivers and their relation to historical changes in gasoline-lead consumption
R. B. Alexander, R. A. Smith
1988, Water Resources Bulletin (24)
Declines in concentrations of dissolved lead occurred at nearly two-thirds of 306 locations on major U.S. rivers from 1974 to 1985. Declines in dissolved lead concentrations are statistically significant (p < 0.10) at approximately one-third of the sampling locations. Statistically significant increases in dissolved lead concentrations occurred at only 6...
Inversion for slip distribution using teleseismic P waveforms: North Palm Springs, Borah Peak, and Michoacan earthquakes
C. Mendoza, S.H. Hartzell
1988, Bulletin of the Seismological Society of America (78) 1092-1111
We have inverted the teleseismic P waveforms recorded by stations of the Global Digital Seismograph Network for the 8 July 1986 North Palm Springs, California, the 28 October 1983 Borah Peak, Idaho, and the 19 September 1985 Michoacan, Mexico, earthquakes to recover the distribution of slip on each of the...
Curie temperature isotherm analysis and tectonic implications of aeromagnetic data from Nevada
R.J. Blakely
1988, Journal of Geophysical Research Solid Earth (93) 11817-11832
Estimates of the depth to the Curie temperature isotherm in Nevada are in accordance with other regional geologic and geophysical information and together can be explained in the context of present-day tectonism. A method to estimate the depth extent of magnetic sources from the statistical properties of magnetic anomalies was...
Assessing the Birkenes Model of stream acidification using a multisignal calibration methodology
Richard P. Hooper, Alex Stone, Nils Christophersen, de Grosbois, Hans M. Seip
1988, Water Resources Research (24) 1308-1316
A revision of the Birkenes model of streamwater acidification has been attempted to incorporate additional chemical and hydrologic information gained in the last 6 years since its original construction. The first stage of this effort has been an analysis of the hydrologic submodel with the goal of extending it to...
Simulation technique for modeling flow on floodplains and in coastal wetlands
Raymond W. Schaffranek, Robert A. Baltzer
1988, Conference Paper
The system design is premised on a proven, areal two-dimensional, finite-difference flow/transport model which is supported by an operational set of computer programs for input data management and model output interpretation. The purposes of the project are (1) to demonstrate the utility of the model for providing useful highway design...
An integrated approach for automated cover-type mapping of large inaccessible areas in Alaska
Michael D. Fleming
1988, Photogrammetric Engineering and Remote Sensing (54) 357-362
The lack of any detailed cover type maps in the state necessitated that a rapid and accurate approach to be employed to develop maps for 329 million acres of Alaska within a seven-year period. This goal has been addressed by using an integrated approach to computer-aided analysis which combines efficient...
Dipolar-dephasing 13C NMR studies of decomposed wood and coalified xylem tissue: Evidence for chemical structural changes associated with defunctionalization of lignin structural units during coalification
Patrick G. Hatcher
1988, Energy & Fuels (2) 48-58
A series of decomposed and coalified gymnosperm woods was examined by conventional solid-state 13C nuclear magnetic resonance (NMR) and by dipolar-dephasing NMR techniques. The results of these NMR studies for a histologically related series of samples provide clues as to the nature of codification reactions that lead to the defunctionalization...
A late Wisconsinan marine incursion into Cape Cod Bay, Massachusetts
R. N. Oldale
1988, Quaternary Research (30) 237-250
Reinterpretation of seismic-reflection data from Cape Cod Bay has produced a revised late Wisconsinan history. Acoustically laminated deposits, originally inferred to be glaciolacustrine, are shown to be glaciomarine by tracing them to glaciomarine mud in Stellwagen Basin, north of Cape Cod Bay. A late Wisconsinan marine deposit of nonglacial origin...
Sedimentary biomarker and isotopic indicators of the paleoclimatic history of the Walker Lake basin, western Nevada
P.A. Meyers, L. V. Benson
1988, Organic Geochemistry (13) 807-813
Walker Lake, a terminal saline lake in western Nevada, has experienced major fluctuations in its water level due to changes in the regional climate during Quaternary times. As part of a paleo-climatological study of western Nevada, we have investigated organic matter δ13C and C/N values and lipid biomarker contents of sediments deposited...
Acute aspergillosis in mallards at Oahe seep near Pierre, South Dakota
W.C. Bair, S. Gay Simpson, R. M. Windingstad
1988, Prairie Naturalist (20) 153-156
Aspergillosis was diagnosed at the cause of death of 158 mallards (Anas platyrhynchos) in January and February 1985 and 11 mallards in December 1985 near Pierre, SD. Isolation of Aspergillus fumigatus from carcass tissues confirmed the diagnosis. The sex ratio of mallards dead from aspergillosis in January and February 1985...
Atmospheric deposition effects on the chemistry of a stream in Northeastern Georgia
G. R. Buell, N.E. Peters
1988, Water, Air, & Soil Pollution (39) 275-291
The quantity and quality of precipitation and streamwater were measured from August 1985 through September 1986 in the Brier Creek watershed, a 440-ha drainage in the Southern Blue Ridge Province of northeastern Georgia, to determine stream sensitivity to acidic deposition. Precipitation samples collected at 2 sites had a volume-weighted average...
Regional assessment of pumpage in southeastern Virginia
Pixie A. Hamilton
1988, Conference Paper
A U.S. Geological Survey investigation was conducted, in cooperation with the Virginia Water Control Board, to analyze the hydrogeology and groundwater flow system in the Coastal Plain physiographic province of southeastern Virginia, and to assess the continued reliability of groundwater as a freshwater resource. To provide a more detailed analysis...
Migration of historical earthquakes in California
C.-Y. King, Z. Ma
1988, Pure and Applied Geophysics PAGEOPH (127) 627-639
Most large earthquakes of magnitude ???6.0 in California during 1852-1987 appear to show a southeast-to-northwest tendency of epicenter migration. This finding is consistent with earlier findings of Savage (1971) for a relatively few large earthquakes along the west coast of North America, and of Wood and Allen (1973) for smaller...
Hydrogen concentrations as an indicator of the predominant terminal electron-accepting reactions in aquatic sediments
Derek R. Lovley, S. Goodwin
1988, Geochimica et Cosmochimica Acta (52) 2993-3003
Factors controlling the concentration of dissolved hydrogen gas in anaerobic sedimentary environments were investigated. Results, presented here or previously, demonstrated that, in sediments, only microorganisms catalyze the oxidation of H2 coupled to the reduction of nitrate, Mn(IV), Fe(III), sulfate, or carbon dioxide. Theoretical considerations suggested that, at steady-state conditions, H2...
Geochemistry and origin of albite gneisses, northeastern Adirondack Mountains, New York
P.R. Whitney, J.F. Olmsted
1988, Contributions to Mineralogy and Petrology (99) 476-484
Albite gneisses containing up to 8.7 percent Na2O and as little as 0.1% K2O comprise a significant part of the Proterozoic Lyon Mountain Gneiss in the Ausable Forks Quadrangle of the northeastern Adirondacks, New York State. Two distinct types of albite gneisses are present. One is a trondhjemitic leucogneiss (LAG)...
Compositions, ages, and diagenetic histories of the carbonate, sulfide, oxide, and phosphatic concretions at Gay Head, Massachusetts
L.J. Poppe, R.F. Commeau, Dennis W. O’Leary
1988, Northeastern Geology (10) 153-168
The calcite/ankerite concretions were formed in a hot, seasonally arid, caliche-prone environment of early Raritan age; the pyrite, marcasite, and siderite concretions precipitated in sediments deposited in low-energy, marshy, estuarine environments of late Raritan age. The phosphate concretions formed in a middle to inner shelf environment. The goethite and lepidocrocite...
The molecular composition of ambers
J.O. Grimalt, Bernd R. T. Simoneit, Patrick G. Hatcher, A. Nissenbaum
1988, Organic Geochemistry (13) 677-690
Bulk (elemental composition, IR, CP/MAS 13C NMR) and molecular (GC-MS) analyses have been performed on a series of ambers and resins derived from different locations (Dominican Republic, Philippines, Canada, Israel, New Zealand, Chile) having diverse botanical affinities (Araucariaceae, Hymenaea) and variable age (from Holocene to Early Cretaceous). No major differences have...
Liquid-vapor relations in the critical region of the system NaCl-H2O from 380 to 415°C: A refined determination of the critical point and two-phase boundary of seawater
James L. Bischoff, Robert J. Rosenbauer
1988, Geochimica et Cosmochimica Acta (52) 2121-2126
Pressure-temperature-composition (P-T-x) relations for coexisting vapor and liquid phases in the system NaCl-H2O were determined experimentally in the critical region from 380 to 415°C. The results provide much improved control on the P-T-x critical line in this region. The critical point of seawater (3.2 wt% NaCl solution), which is bracketed in the...
COEXISTING GALENA, PbS//S//S AND SULFOSALTS: EVIDENCE FOR MULTIPLE EPISODES OF MINERALIZATION IN THE ROUND MOUNTAIN AND MANHATTAN GOLD DISTRICTS, NEVADA.
Eugene E. Foord, Daniel R. Shawe, Nancy M. Conklin
1988, Canadian Mineralogist (26 p) 355-376
Studies of galena and Pb-Bi-Ag-Cu(Hg) sulfosalts of varied compositions in the Round Mountain and Manhattan gold districts of Nevada corroborate the occurrence of several distinct mineralized systems characterized by different mineral compositions and assemblages. The different episodes of mineralization are related to different Cretaceous and Tertiary magmatic-hydrothermal events, although the...
Conversion of Cartesian coordinates from and to Generalized Balanced Ternary addresses
Jan W. van Roessel
1988, Photogrammetric Engineering and Remote Sensing (54) 1565-1570
Hexagonal grids have several advantages over square grids, such as a greater angular resolution and unambiguous connectivity. The Generalized Balanced Ternary (GBT) system is a spatial addressing method for hexagonal grids in which the hexagons are arranged in hierarchical aggregates, and which accommodates vector operations in GBT space. Efficient algorithms...
Intermediate-term, pre-earthquake phenomena in California, 1975-1986, and preliminary forecast of seismicity for the next decade
R. L. Wesson, C. Nicholson
1988, Pure and Applied Geophysics PAGEOPH (126) 407-446
Intermediate-term observations preceding earthquakes of magnitude 5.7 or greater in California from 1975 through 1986 suggest that: (1) The sudden appearance of earthquakes in a previously inactive area indicates an increased likelihood of a significant earthquake in that area for a period from days to years; (2) these larger earthquakes...
The radiocarbon budget for Mono Lake: An unsolved mystery
W.S. Broecker, R. Wanninkhof, G. Mathieu, T.-H. Peng, S. Stine, S. Robinson, A. Herczeg, M. Stuiver
1988, Earth and Planetary Science Letters (88) 16-26
Since 1957 the 14C/C ratio of the dissolved inorganic carbon in Mono Lake has risen by about 60‰. The magnitude of this increase is about four times larger than that expected from the invasion of bomb-produced14C from the atmosphere. We have eliminated the following explanations: (1) measurement error, (2) an unusually...
The chemical evolution of a travertine-depositing stream: Geochemical processes and mass transfer reactions
Michelle M. Lorah, Janet S. Herman
1988, Water Resources Research (24) 1541-1552
This field study focuses on quantitatively defining the chemical changes occurring in Falling Spring Creek, a travertine-depositing stream located in Alleghany County, Virginia. The processes of CO2outgassing and calcite precipitation or dissolution control the chemical evolution of the stream. The observed chemical composition of the water was used with the...
Wetland Boundary Determination in the Great Dismal Swamp Using Weighted Averages
Virginia Carter, Mary Keith Garrett, Patricia T. Gammon
1988, Water Resources Bulletin (24) 297-306
A weighted average method was used to analyze transition zone vegetation in the Great Dismal Swamp to determine if a more uniform determination of wetland boundaries can be made nationwide. The method was applied to vegetation data collected on four transects and three vertical layers across the wetland-to-upland transition zone...
