Pleistocene glaciation of volcano Ajusco, central Mexico, and comparison with the standard Mexican glacial sequence
Sidney White, S. Valastro
1984, Quaternary Research (21) 21-35
Three Pleistocene glaciations and two Holocene Neoglacial advances occurred on volcano Ajusco in central Mexico. Lateral moraines of the oldest glaciation, the Marqués, above 3250 m are made of light-gray indurated till and are extensively modified by erosion. Below 3200 m the till is dark red, decomposed, and buried beneath...
Modeling behavior of prescribed fires in Yosemite National Park
J. W. van Wagtendonk, S.J. Botti
1984, Journal of Forestry (82) 479-484
The National Fire Danger Rating System and the Fire Behavior Prediction System were tested on prescribed fires burning underneath canopies in six fuel types in Yosemite National Park, California. The mean error for rate of spread was +0.03 foot per minute for the NFDRS and -0.15 foot for the...
DEFINITION FOR TALC.
Malcolm Ross
Levadie Benjamin, editor(s)
1984, Conference Paper, ASTM Special Technical Publication
Talc is a naturally occurring single-phase mineral having the approximate chemical formula Mg//3Si//4O//1//0(OH)//2 and a specific type of crystal structure. Talc commonly forms by hydrothermal alteration of rocks rich in magnesium and iron (ultramafic rocks) and by low-grade thermal metamorphism of siliceous dolomites. The fact that talc often occurs in...
LINEAR MODELS FOR MANAGING SOURCES OF GROUNDWATER POLLUTION.
Steven M. Gorelick, Sven-Ake Gustafson
Noye JohnFletcher Clive, editor(s)
1984, Conference Paper
Mathematical models for the problem of maintaining a specified groundwater quality while permitting solute waste disposal at various facilities distributed over space are discussed. The pollutants are assumed to be chemically inert and their concentrations in the groundwater are governed by linear equations for advection and diffusion. The aim is...
On the ability to detect the influence of spawning stock on recruitment
C.P. Goodyear, Sigurd W. Christensen
1984, North American Journal of Fisheries Management (4) 186-193
Simulated observations of spawning stock size, recruitment, and two random environmental variables were obtained from a density-independent Leslie matrix model. Recruitment to Age 1 was directly proportional to population fecundity but strongly influenced by the effects of the random environmental variables. The simulated observations were subjected to multiple regression analysis...
HYDRAULIC RESEARCH - U. S. GEOLOGICAL SURVEY.
Verne R. Schneider
Schreiber David L., editor(s)
1984, Conference Paper
Research at the Gulf Coast Hydroscience Center near Bay St. Louis, Mississippi, is being conducted in an indoor laboratory, and an outdoor laboratory. Much of the current indoor lab research is directed at improved methods of measuring flow. A towing tank and submerged jet tank are used for calibrating velocity...
Deformation of clinopyroxenite: Evidence for a transition in flow mechanisms and semibrittle behavior
S. H. Kirby, A. K. Kronenberg
1984, Journal of Geophysical Research Solid Earth (89) 3177-3192
A systematic suite of constant strain rate experiments was performed on a vacuum-dried, high-purity, fine-grained clinopyroxenite using NaCl and NaF as confining media in a Griggs-type piston-cylinder apparatus. The experiments were carried out over a range of temperatures from 400° to 1100°C, strain rates from 10−3 to 10−7 s−1, and confining pressures...
Response of avian communities to herbicide-induced vegetation changes
Michael L. Morrison, E. Charles Meslow
1984, Journal of Wildlife Management (48) 14-22
The relationships between avian communities and herbicide modification of vegetation were analyzed on early-growth clear-cuts in western Oregon that had received phenoxy herbicide treatment 1 or 4 years previously. For both 1 and 4 years post-spray, vegetation development was greater in the third height interval (> 3.0 m) on untreated...
Effects of permanent trap response in capture probability on Jolly-Seber capture-recapture model estimates
James D. Nichols, James E. Hines, Kenneth H. Pollock
1984, Journal of Wildlife Management (48) 289-294
No abstract available. ...
Potential impacts of water diversion on fishery resources in the Great Lakes
Bruce A. Manny
1984, Fisheries (9) 19-23
Uses of Great Lakes water within the Great Lakes basin are steadily increasing, and critical water shortages elsewhere may add to the demands for diversions of water out of the basin in the near future. The impacts of such diversions on fish in the Great Lakes must be considered in...
Modification of wave-cut and faulting-controlled landforms
Thomas C. Hanks, R.C. Bucknam, K. R. Lajoie, R. E. Wallace
1984, Journal of Geophysical Research Solid Earth (89) 5771-5790
From a casual observation that the form of degraded fault scarps resembles the error function, this investigation proceeds through an elementary diffusion equation representation of landform evolution to the application of the resulting equations to the modern topography of scarplike landforms. The morphologic observations can be analyzed either in the...
Modeling crater topography and albedo from monoscopic Viking orbiter images: 1. Methodology
P. A. Davis, L.A. Soderblom
1984, Journal of Geophysical Research Solid Earth (89) 9449-9457
A new photoclinometric technique for extraction of topographic data from single planetary images is presented that overcomes many previous limitations of photoclinometry. The procedure fully compensates for oblique viewing geometry prevalent in spacecraft images. Albedo variations have been one of the most serious obstacles in the application of photoclinometry to...
Proton and metal ion binding to natural organic polyelectrolytes—II. Preliminary investigation with a peat and a humic acid
J.A. Marinsky, M.M. Reddy
1984, Organic Geochemistry (7) 215-221
We summarize here experimental studies of proton and metal ion binding to a peat and a humic acid. Data analysis is based on a unified physico-chemical model for reaction of simple ions with polyelectrolytes employing a modified Henderson-Hasselbalch equation. Peat exhibited an apparent intrinsic acid dissociation constant of 10−4.05, and...
Magmatic epidote and its petrologic significance
E-An Zen, J. M. Hammarstrom
1984, Geology (12) 515-518
Epidote is a major magmatic mineral in tonalite and granodiorite in a belt coextensive with the Mesozoic accreted terranes between northern California and southeastern Alaska. Textural and chemical evidence indicates that epidote crystallized as a relatively late but magmatic mineral that formed through...
Distribution of trace elements in coal from the Powhatan No. 6 mine, Ohio
C.A. Palmer, R.H. Filby
1984, Fuel (63) 318-328
Size and density separates of low-temperature-ashed coal from the Powhatan No. 6 mine, Ohio, have been used to determine the mode of occurrence of 28 minor and trace elements in coal. The size distribution of the major minerals has been determined, and correlations of trace elements with major minerals have...
A Model of Regional Ground-Water Flow in Secondary-Permeability Terrane
J. M. Gerhart
1984, Groundwater (22) 168-175
The ground-water flow system in the Lower Susquehanna River Basin in Pennsylvania and Maryland can be considered as one complex unconfined aquifer in which secondary porosity and permeability are the dominant influences on the occurrence and flow of ground water. The degree of development of...
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...
Uranium mineralization in response to regional metamorphism at Lilljuthatten, Sweden
J. S. Stuckless, B. Troeng
1984, Economic Geology (79) 509-528
Analyses of six mineralized and five nonmineralized whole-rock drill core samples from the uranium deposit at Lilljuthatten yield a lead-lead isochron age of 420 + or - 1 m.y. This age corresponds to the last stage of the Caledonian Orogeny. None of the isotopic systems examined have completely retained the...
Copper and cobalt in aquatic mosses and stream sediments from the Idaho Cobalt Belt
J. A. Erdman, P.J. Modreski
1984, Journal of Geochemical Exploration (20) 75-84
Samples of stream sediments and aquatic mosses were collected from nine sites across several mineralized zones at the southeasternmost extension of the Idaho Cobalt Belt. Because the steepness of the terrain and the attendant high flow rate of the streams made it difficult to obtain adequate sediment samples, mosses were...
Creep behavior of submarine sediments
Armand J. Silva, J.S. Booth
1984, Geo-Marine Letters (4) 215-219
A series of experiments on drained creep of marine sediment indicates that strength degradation results from the creep process, which implies an associated reduction in slope stability. Furthermore, the highest creep potential of a sediment may be at its preconsolidation stress. Results from the experiments on samples from Georges Bank...
MICROCHARACTERIZATION OF ARSENIC- AND SELENIUM-BEARING PYRITE IN UPPER FREEPORT COAL, INDIANA COUNTY, PENNSYLVANIA.
J.A. Minkin, R. B. Finkelman, C.L. Thompson, E. C. T. Chao, L.F. Ruppert, H. Blank, C. B. Cecil
1984, Scanning Electron Microscopy 1515-1529
Optical and scanning electron microscope as well as electron and proton microprobe techniques have been used in a detailed investigation of the modes of occurrence of arsenic and selenium in pyrite in Upper Freeport coal from the Homer City area, Indiana County, Pennsylvania. Polished blocks were prepared from columnar samples...
Geochemistry of tholeiitic and alkalic lavas from the Koolau Range, Oahu, Hawaii: Implications for Hawaiian volcanism
M.F. Roden, F.A. Frey, D.A. Clague
1984, Earth and Planetary Science Letters (69) 141-158
Lavas of the post-erosional, alkalic Honolulu Volcanics have significantly lower 87Sr/86Sr and higher 143Nd/144Nd than the older and underlying Koolau tholeiites which form the Koolau shield of eastern Oahu, Hawaii. Despite significant compositional variation within lavas forming the Honolulu Volcanics, these lavas are isotopically...
ROLE OF SPATIAL RESOLUTION AND SPECTRAL CONTENT IN CHANGE DETECTION.
Valerie A. Milazzo
1984, Conference Paper
Summary form only given, as follows. Advancements in remote sensing technology have brought improvements and sophistication to modern remote sensor systems, especially those aboard earth resources satellites. These improvements have considerbly expanded the capabilities of the newer sensor systems, particularly the capability to achieve greatly increased spatial and spectral resolution...
Inverse problems for torsional modes.
C. Willis
1984, Geophysical Journal of the Royal Astronomical Society (78) 847-853
Considers a spherically symmetric, non-rotating Earth consisting of an isotropic, perfect elastic material where the density and the S-wave velocity may have one or two discontinuities in the upper mantle. Shows that given the velocity throughout the mantle and the crust and given the density in the lower mantle, then...
Reflectance spectroscopy: Quantitative analysis techniques for remote sensing applications
Roger N. Clark, T. L. Roush
1984, Journal of Geophysical Research (89) 6329-6340
Several methods for the analysis of remotely sensed reflectance data are compared, including empirical methods and scattering theories, both of which are important for solving remote sensing problems. The concept of the photon mean optical path length and the implications for use in modeling reflectance spectra are presented. It is...
