An estimate of hydrothermal fluid residence times and vent chimney growth rates based on 210Pb Pb ratios and mineralogic studies of sulfides dredged from the Juan de Fuca Ridge
D. Kadko, R. Koski, M. Tatsumoto, R. Bouse
1985, Earth and Planetary Science Letters (76) 35-44
The210PbPb ratios across two sulfide samples dredged from the Juan de Fuca Ridge are used to estimate the growth rate of the sulfide material and the residence time of the hydrothermal fluid within the oceanic crust from the onset of basalt alteration.210Pb...
How the geomagnetic field vector reverses polarity
M. Prevot, E. A. Mankinen, C. S. Grommé, R. S. Coe
1985, Nature (316) 230-234
A highly detailed record of both the direction and intensity of the Earth's magnetic field as it reverses has been obtained from a Miocene volcanic sequence. The transitional field is low in intensity and is typically non-axisymmetric. Geomagnetic impulses corresponding to astonishingly high rates of change of the field sometimes...
Anomalous 13C enrichment in modern marine organic carbon
M.A. Arthur, W.E. Dean, George E. Claypool
1985, Nature (315) 216-218
Marine organic carbon is heavier isotopically (13C enriched) than most land-plant or terrestrial organic C1. Accordingly, ??13C values of organic C in modern marine sediments are routinely interpreted in terms of the relative proportions of marine and terrestrial sources of the preserved organic matter2,3. When independent geochemical techniques are used...
Redescription of Bellerophon bittneri (Gastropoda: Triassic) from Wyoming.
E. L. Yochelson, D.W. Boyd, B. Wardlaw
1985, Contributions to Geology - University of Wyoming, Laramie (23) 99-104
Bellerophon bittneri Newell and Kummel is an Early Triassic bellerophontacean from the Dinwoody Formation in the Wind River Mountains. The available type material consists of one fair, but incomplete, external mold, which resembles a Bellerophon but is actually a Retispira. After repeated search, additional specimens were found at one locality...
Origin of discontinuities in coal-bearing strata at roaring creek (basal Pennsylvanian of Indiana)
W.J. Nelson, Donald L. Eggert, William A. DiMichele, A.C. Stecyk
1985, International Journal of Coal Geology (4) 355-370
Basal Pennsylvanian coal-bearing strata exposed along Roaring Creek, west-central Indiana, exhibit extreme lateral discontinuity. Coal seams abruptly change in thickness and elevation; they split, grade into shale, are cut out by channels and disrupted by soft-sediment deformational structures. Initial sediments were...
Aeromagnetic map and analysis of aeromagnetic and aeroradioactivity data in the Blood Mountain, Chattahoochee, and Tray Mountain Roadless Areas, northern Georgia
David L. Daniels
1985, Miscellaneous Field Studies Map 1347-E
The data for the aerornagnetic map of the Blood Mountain, Chattahoochee, and Tray Mountain Roadless Areas and vicinity were compiled from two separate airborne surveys {U.S. Geological Survey, 1977, 1981) produced in cooperation with the State of Georgia. These surveys were flown by fixed - wing aircraft in 1976 and...
PREPRO: a computer program for encoding regional exploration data for use in characteristic analysis
N.J. Bridges, J.T. Hanley, R.B. McCammon
1985, Computers & Geosciences (11) 513-519
The preprocessor (PREPRO) computer program offers the exploration geologist a variety of options for encoding regional exploration data into ternary form for use in characteristic analysis. PREPRO's options include variable-input formats, cursor input, ordering among a set of input variables, and selectable ternary transformations. Moreover, the program provides for the...
An empirical equation of state for hydrothermal seawater (3.2 percent NaCl)
James L. Bischoff, Robert J. Rosenbauer
1985, American Journal of Science (285) 725-763
No abstract available....
MONITORING THE EARTH - TOO MANY PLAYERS?
Gene A. Thorley
1985, Conference Paper, Technical Papers of the American Society of Photogrammetry, Annual Meeting
Remote sensing from satellites provides a unique tool to measure the parameters of the Earth on a worldwide scale. A number of organizations are currently engaged in, or proposing to embark on, worldwide measurement/monitoring programs. Program objectives vary in type and complexity, including a form of technical library and an...
Tidal variation of seismic travel times in a Massachusetts granite quarry
Hsi-Ping Liu, Eugene D. Sembera, Robert E. Westerlund, Jon B. Fletcher, Paul Reasenberg, Duncan C. Agnew
1985, Geophysical Research Letters (12) 243-246
Conflicting results on tidal variation of seismic travel times exist in the literature. With improved methods, we have conducted a seismic survey at a Massachusetts granite quarry. The survey was conducted in the intervals (230d 23h, 231d11h) and (231d22h, 233d10h), 1983 (U.T.) along a 148 m...
HIGH-ANGLE AEOLIAN CROSSBEDDING AT TRAIL RIDGE, FLORIDA.
Eric Force, Tom Garnar
1985, Industrial Minerals
This paper described new evidence concerning the origin of the Trail Ridge mineral sands deposit in Florida. Rarely exposed sections of the orebody exhibit structures indicative of sand dune formation rather than coastal beach sand accumulation. The implications for mineral sands exploration, and therefore resources, in the southeastern USA are...
Spatial analysis of extension fracture systems: A process modeling approach
C.C. Ferguson
1985, Journal of the International Association for Mathematical Geology (17) 403-425
Little consensus exists on how best to analyze natural fracture spacings and their sequences. Field measurements and analyses published in geotechnical literature imply fracture processes radically different from those assumed by theoretical structural geologists. The approach adopted in this paper recognizes that disruption of rock layers by layer-parallel extension results...
Professional registration of government engineers
Thomas J. Buchanan
1985, Journal of Professional Issues in Engineering (111) 81-87
Government engineers often are not required to be registered in the state in which they practice, even though their counterparts in the private sector must be registered. Government engineers have a responsibility to safeguard the public health and safety, and must develop in the public a sense of confidence that...
A seismic-refraction profile across the San Andreas, Sargent, and Calaveras faults, west-central California
Walter D. Mooney, Robert H. Colburn
1985, Bulletin of the Seismological Society of America (75) 175-191
In 1981, the United States Geological Survey recorded a seismic-refraction profile across the southern Santa Cruz Mountains in west-central California to examine the shallow velocity structure of this seismogenic region. This 40-km-long profile, which consisted of three shotpoints, extended northeastward from near Watsonville, California, to Coyote Lake, crossing the San...
PROCEDURES FOR ACCURATE PRODUCTION OF COLOR IMAGES FROM SATELLITE OR AIRCRAFT MULTISPECTRAL DIGITAL DATA.
Joseph S. Duval
1985, Journal of Imaging Technology (10) 16-22
Because the display and interpretation of satellite and aircraft remote-sensing data make extensive use of color film products, accurate reproduction of the color images is important. To achieve accurate color reproduction, the exposure and chemical processing of the film must be monitored and controlled. By using a combination of sensitometry,...
Linear inversion of transmitted acoustic wave fields for three-dimensional modulus and density perturbations using a born-type approximation
Douglas A. Stauber
1985, Bulletin of the Seismological Society of America (75) 93-114
A Born approximation is used to linearize the relationship, in the horizontal-wavenumber and frequency domains, between lateral perturbations of modulus and density in a layered half-space and the acoustic wave field observed at the surface when a plane wave is incident from below. The resulting equations can be used to...
Time scales of circulation and mixing processes of San Francisco Bay waters
R. A. Walters, R. T. Cheng, T. J. Conomos
1985, Hydrobiologia (129) 13-36
Conceptual models for tidal period and low-frequency variations in sea level, currents, and mixing processes in the northern and southern reaches of San Francisco Bay describe the contrasting characteristics and dissimilar processes and rates in these embayments: The northern reach is a partially mixed estuary whereas the southern reach...
Ground-water flow in the Coastal Plain aquifers of South Carolina
W. R. Aucott, G. K. Speiran
1985, Groundwater (23) 736-745
The characteristics of the Coastal Plain aquifers of South Carolina are being studied as a part of the Regional Aquifer System Analysis program of the United States Geological Survey. Potentiometric maps were constructed for the Middendorf aquifer of Cretaceous age and for the Floridan...
Palmer Drought Severity Index as a Measure of Hydrologic Drought
William M. Alley
1985, Journal of the American Water Resources Association (21) 105-114
The Palmer Drought Severity Index (PDSI) for climatic divisions in New Jersey is compared to the occurrence within each climatic division of streamflows in their lower quartile for the month (streamflow index) and ground-water levels in their lower quartile for the month (ground-water index). These indices are found to have...
EARTHQUAKE HAZARDS IN THE OFFSHORE ENVIRONMENT.
Robert A. Page, Peter W. Basham
1985, Ocean science and engineering (10) 195-352
This report discusses earthquake effects and potential hazards in the marine environment, describes and illustrates methods for the evaluation of earthquake hazards, and briefly reviews strategies for mitigating hazards. The report is broadly directed toward engineers, scientists, and others engaged in developing offshore resources. The continental shelves have become a...
Assessment of the fisheries and limnology in Lake F.D. Roosevelt, 1980-1983
T.T. Terrell
1985, Report
No abstract available ...
Bioenergetics of juvenile salmon during the spring outmigration
D.W. Rondorf, M.S. Dutchuk, A.S. Kolok, M.L. Gross
1985, Report
No abstract available ...
Development of an effective transport media for juvenile spring Chinook salmon to mitigate stress and improve smolt survival during Columbia River fish hauling operations
Gary Wedemeyer, A. Palmisano, L. Salsbury
1985, Report
No abstract available ...
Stable-isotope evidence for a magmatic component in fumarole condensates from Augustine Volcano, Cook Inlet, Alaska, U.S.A.
J.A. Viglino, R.S. Harmon, J. Borthwick, N.L. Nehring, R.J. Motyka, L. D. White, D. A. Johnston
1985, Chemical Geology (49) 141-157
D/H and 18O 16O ratios have been determined for fumarole condensates from Augustine Volcano, an active calc-alkaline stratovolcano in Lower Cook Inlet, Alaska. The isotopic data for the condensates form a linear ?? D-?? 18O array from low-temperature fluids (< 100??C) which are essentially local meteoric water (?? D...
Genesis and evolution of water in a two-mica pluton: A hydrogen isotope study
R. H. Brigham, J. R. O’Neil
1985, Chemical Geology (49) 159-177
Measurements were made of the hydrogen isotope composition of 74 samples of muscovite, biotite, vein quartz and whole rocks from the Papoose Flat pluton, eastern California, U.S.A., and adjacent metamorphic and sedimentary rocks in order to elucidate the genesis and evolution of water and hydrous minerals in a two-mica granodiorite....
