A simple model of ice segregation using an analytic function to model heat and soil-water flow
T. V. Hromadka II, G. L. Guymon
1984, Journal of Energy Resources Technology, Transactions of the ASME (106) 515-520
For slowly moving freezing fronts in soil, the heat-transport equation may be approximated by the Laplacian of temperature. Consequently, potential theory may be assumed to apply and the temperature state can be approximated by an analytic function. The movement of freezing fronts may be approximated by a time-stepped solution of...
The impact of uncertainties in hydrologic measurement on phosphorus budgets and empirical models for two Colorado reservoirs.
James W. LaBaugh, T. C. Winter
1984, Limnology and Oceanography (29) 322-339
Water budgets and related chemical budgets of aquatic ecosystems commonly are interpreted without reference to uncertainties resulting from errors of measurement. The importance of such uncertainties in the use and interpretation of the phosphorus budgets of two Colorado reservoirs was determined....
EVALUATION OF LOW-SUN ILLUMINATED LANDSAT-4 THEMATIC MAPPER DATA FOR MAPPING HYDROTHERMALLY ALTERED ROCKS IN SOUTHERN NEVADA.
Melvin H. Podwysocki, Marty S. Power, Jack Salisbury, O. D. Jones
1984, Conference Paper
Landsat-4 Thematic Mapper (TM) data of southern Nevada collected under conditions of low-angle solar illumination were digitally processed to identify hydroxyl-bearing minerals commonly associated with hydrothermal alteration in volcanic terrains. Digital masking procedures were used to exclude shadow areas and vegetation and thus to produce a CRC image suitable for...
Thermal conductivity determinations on solid rock - a comparison between a steady-state divided-bar apparatus and a commercial transient line-source device
J.H. Sass, C. Stone, R. J. Munroe
1984, Journal of Volcanology and Geothermal Research (20) 145-153
Two apparatuses were used to measure thermal conductivities on pairs of contiguous samples from 17 specimens of solid rock: the USGS divided-bar apparatus, a steadystate comparative method, and the Shotherm "Quick Thermal Meter" (QTM), which employs a transient strip heat source. Both devices were calibrated relative to fused silica. Both...
Heating of a fully saturated Darcian half-space: Pressure generation, fluid expulsion, and phase change
P. Delaney
1984, International Journal of Heat and Mass Transfer (27) 1327-1335
Analytical solutions are developed for the pressurization, expansion, and flow of one- and two-phase liquids during heating of fully saturated and hydraulically open Darcian half-spaces subjected to a step rise in temperature at its surface. For silicate materials, advective transfer is commonly unimportant in the liquid region; this is not...
Geology of El Chichon volcano, Chiapas, Mexico
W. A. Duffield, R.I. Tilling, R. Canul
1984, Journal of Volcanology and Geothermal Research (20) 117-132
The (pre-1982) 850-m-high andesitic stratovolcano El Chicho??n, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, Me??xico. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chicho??n is built on Tertiary siltstone and sandstone,...
Comparative geochronology in the reversely zoned plutons of the Bottle Lake Complex, Maine: U-Pb on zircons and Rb-Sr on whole rocks
R. A. Ayuso, Joseph G. Arth, A.K. Sinha, J. Carlson, D. R. Wones
1984, Contributions to Mineralogy and Petrology (88) 113-125
The Bottle Lake Complex is a composite granitic batholith emplaced into Cambrian to Lower Devonian metasedimentary rocks. Both plutons (Whitney Cove and Passadumkeag River) are very coarse grained hornblende and biotite-bearing granites showing petrographic and geochemical reverse zonation. Two linear whole rock Rb/Sr isochrons on xenolith-free Whitney Cove and Passadumkeag...
Laboratory studies of volcanic jets
S. W. Kieffer, B. Sturtevant
1984, Journal of Geophysical Research Solid Earth (89) 8253-8268
The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. In preliminary experiments, pure gases are erupted from small reservoirs. The gases used are Freon 12 and Freon 22,...
Holocene age of the Yuha burial: Direct radiocarbon determinations by accelerator mass spectrometry
Thomas W. Stafford Jr., A.J.T. Jull, T.H. Zabel, D.J. Donahue, R.C. Duhamel, K. Brendel, C.V. Haynes Jr., J. L. Bischoff, L.A. Payen, R.E. Taylor
1984, Nature (308) 446-447
The view that human populations may not have arrived in the Western Hemisphere before about 12,000 radiocarbon yr BP1,2 has been challenged by claims of much greater antiquity for a small number of archaeological sites and human skeleton samples. One such site is the Homo sapiens sapiens cairn burial excavated...
U-Pb zircon geochronology and geological evolution of the Halaban- Al Amar region of the eastern Arabian Shield, Kingdom of Saudi Arabia.
J. S. Stacey, D. B. Stoeser, W.R. Greenwood, L. B. Fischer
1984, Journal of the Geological Society (141) 1043-1055
U-Pb zircon model ages for eleven major units from the Halaban-Al Amar region of the eastern Arabian Shield indicate three stages of evolution: (1) plate convergence, (2) plate collision, and (3) post-orogenic intracratonic activity.Convergence occurred between the western Afif and eastern Ar Rayn plates that were separated by oceanic crust....
Computer-assisted cartography: an overview.
S.C. Guptill, L.E. Starr
1984, South African Journal of Photogrammetry, Remote Sensing & Cartography (14) 13-18
An assessment of the current status of computer-assisted cartography, in part, is biased by one's view of the cartographic process as a whole. From a traditional viewpoint we are concerned about automating the mapping process; from a progressive viewpoint we are concerned about using the tools of computer science to...
Upwarp of anomalous asthenosphere beneath the Rio Grande rift
E.C. Parker, P.M. Davis, J.R. Evans, H. M. Iyer, K.H. Olsen
1984, Nature (312) 354-356
Continental rifts are possible analogues of mid-ocean ridges, although major plate tectonic features are less clearly observed1. Current thermal models of mid-ocean ridges2-4 consist of solid lithospheric plates overlying the hotter, less viscous asthenosphere, with plate thickness increasing away from the ridge axis. The lithospheric lower boundary lies at or...
Dendrogeomorphic evidence of debris flow frequency and magnitude at Mount Shasta, California
Cliff R. Hupp
1984, Environmental Geology and Water Sciences (6) 121-128
Debris-flow deposits and woody vegetation adjacent to and growing within the channels of Whitney, Bolam, Mud, Ash, and Panthe creeks provide a 300-year record of debris-flow frequency at Mount Shasta Dendrochronologic (tree-ring) dating methods for the debris flows proved consistent with available documented records of debris flows Nine debris flows...
Volatiles of Mount St. Helens and their origins
I. Barnes
1984, Journal of Volcanology and Geothermal Research (22) 133-146
Analyses have been made of gases in clouds apparently emanating from Mount St. Helens. Despite appearances, most of the water in these clouds does not issue from the volcano. Even directly above a large fumarole ??D and ?? 18O data indicate that only half the water can come from the...
APPLICATION OF SPATIAL INFORMATION TECHNOLOGY TO PETROLEUM RESOURCE ASSESSMENT ANALYSIS.
Betty M. Miller, Michael A. Domaratz
1984, Conference Paper
Petroleum resource assessment procedures require the analysis of a large volume of spatial data. The US Geological Survey (USGS) has developed and applied spatial information handling procedures and digital cartographic techniques to a recent study involving the assessment of oil and gas resource potential for 74 million acres of designated...
Modification of δ D values in eastern Nevada granitoid rocks spatially related to thrust faults
D. E. Lee, Irving Friedman, J.D. Gleason
1984, Contributions to Mineralogy and Petrology (88) 288-298
Stable isotope data have been determined for 13 Mesozoic and Tertiary plutons in eastern Nevada and nearby Utah. In the southern Snake Range of eastern Nevada, where relations are best exposed and have been most intensively studied, δD, δ 18O, and apparent K-Ar ages depend on proximity to the Snake...
TECHNIQUE FOR ENHANCING DIGITAL COLOR IMAGES BY CONTRAST STRETCHING IN MUNSELL COLOR SPACE.
Fred A. Kruse, Gary L. Raines
1984, Conference Paper
The Munsell color system can be used to further enhance the appearance of high-quality digital color-composite images. A color-balanced 'standard' color-composite image is first produced using any desired contrast stretching algorithm. The stretched digital data are then transformed into the cylindrical Munsell color space. An enhanced version of a color-composite...
Landslides caused by earthquakes
D. K. Keefer
1984, Geological Society of America Bulletin (95) 406-421
Data from 40 historical world-wide earthquakes were studied to determine the characteristics, geologic environments, and hazards of landslides caused by seismic events. This sample of 40 events was supplemented with intensity data from several hundred United States earthquakes to study relations between landslide...
Oxygen isotope evidence for submarine hydrothermal alteration of the Del Puerto ophiolite, California
Peter Schiffmant, A.E. Williams, R.C. Evarts
1984, Earth and Planetary Science Letters (70) 207-220
The oxygen isotope compositions and metamorphic mineral assemblages of hydrothermally altered rocks from the Del Puerto ophiolite and overlying volcaniclastic sedimentary rocks at the base of the Great Valley sequence indicate that their alteration occurred in a submarine hydrothermal system. Whole rock δ18O compositions decrease progressively down section (with increasing...
Oxygen isotope calibration of the onset of ice-rafting and history of glaciation in the North Atlantic region
N. J. Shackleton, J. Backman, H. Zimmerman, D.V. Kent, M.A. Hall, David G. Roberts, D. Schnitker, J.G. Baldauf, A. Desprairies, R. Homrighausen, P. Huddlestun, J.B. Keene, A.J. Kaltenback, K.A.O. Krumsiek, A.C. Morton, J.W. Murray, J. Westberg-Smith
1984, Nature (307) 620-623
We report here that DSDP Site 552A, cored with the hydraulic piston corer on the west flank of Rockall Bank, recovered an undisturbed sequence of alternating white deep-sea carbonate oozes and dark-coloured layers that are rich in glacial debris. Oxygen isotope analysis of the sequence together with detailed nannofossil and...
USGS adopts revised criteria and terms for hazards notices
D. Finley
1984, Earthquake Information Bulletin (USGS) (16) 190-190
Catastrophic isotopic modification of rhyolitic magma at times of caldera subsidence, Yellowstone Plateau Volcanic Field
W. Hildreth, R.L. Christiansen, J. R. O’Neil
1984, Journal of Geophysical Research Solid Earth (89) 8339-8369
The Yellowstone Plateau volcanic field has undergone repeated eruption of rhyolitic magma strongly depleted in 18O. Large calderas subsided 2.0, 1.3, and 0.6 Ma ago, on eruption of ash flow sheets that represent at least 2500, 280, and 1000 km3 of zoned magma. More than 60 other rhyolite lavas and tuffs permit...
Growth and food habits of hybrid carp, Ctenopharyngodon idella x Aristichthys nobilis, from aerated and non-aerated ponds
J.V. Shireman, F.J. Aldridge, R.W. Rottmann
1984, Journal of Fish Biology (23) 595-604
Hybrid grass carp fry (Ctenopharyngodon idella×Aristichthys nobilis) were stocked into 0·04 ha ponds with and without paddlewheel aeration. Fish in the paddlewheel and non-paddlewheel pond, preyed upon identical organisms, but in different proportions. Fish in the paddlewheel ponds grew at significantly greater rates....
Geochemistry of ferromanganese nodules from DOMES site a, Northern Equatorial Pacific: Multiple diagenetic metal sources in the deep sea
S.E. Calvert, D.Z. Piper
1984, Geochimica et Cosmochimica Acta (48) 1913-1928
The major and minor element composition of ferromanganese nodules from DOMES Site A has been determined by X-ray fluorescence methods. Three phases appear to control the bulk compositions: Mn and Fe oxyhydroxides and aluminosilicates. Relatively wide compositional variations are evident throughout the area. Nodules with high Mn/Fe ratios, high Cu,...
Arsenic and antimony in geothermal waters of Yellowstone National Park, Wyoming, USA
R. E. Stauffer, J. M. Thompson
1984, Geochimica et Cosmochimica Acta (48) 2547-2561
A total of 268 thermal spring samples were analyzed for total soluble As using reduced molybdenum-blue; 27 of these samples were also analyzed for total Sb using flame atomic absorption spectrometry. At Yellowstone the ClAs">ClAs atomic ratio is nearly constant among neutral-alkaline springs with Cl >...
