Lead and strontium isotopes and related trace elements as genetic tracers in the Upper Cenozoic rhyolite-basalt association of the Yellowstone Plateau volcanic field
B. R. Doe, W.P. Leeman, R.L. Christiansen, C. E. Hedge
1982, Journal of Geophysical Research Solid Earth (87) 4785-4806
Supported by various field geologic and petrologic data, the contents of Pb, U, Th, Rb, and Sr and the isotopic compositions of Pb and Sr for upper Cenozoic volcanic rocks of the Yellowstone Plateau volcanic field are consistent with the hypothesis of derivation of the basaltic and rhyolitic magmas by...
The UThPb age of equilibrated L chondrites and a solution to the excess radiogenic Pb problem in chondrites
D.M. Unruh
1982, Earth and Planetary Science Letters (58) 75-94
U, Th, and Pb analyses of whole-rock and troilite separates from seven L chondrites suggest that the excess radiogenic Pb relative to U and the large variations in PbPb model ages commonly observed in chondritic meteorites are largely due to terrestrial Pb contamination induced prior to...
The graphic cell method: a new look at digitizing geologic maps
J.T. Hanley
1982, Computers & Geosciences (8) 149-161
The graphic cell method is an alternative method of digitizing areal geologic information. It involves a discrete-point sampling scheme in which the computer establishes a matrix of cells over the map. Each cell and the whole cell is assigned the identity or value of the geologic information that is recognized...
Unroofing history of a suture zone in the Himalaya of Pakistan by means of fission-track annealing ages
P.K. Zeitler, R.A.K. Tahirkheli, C. W. Naeser, N.M. Johnson
1982, Earth and Planetary Science Letters (57) 227-240
The uplift history of the Swat Valley and Hazara region of northwestern Pakistan has been established using 22 fission-track dates on apatite, zircon and sphene. A major fault, the Main Mantle Thrust (MMT) strikes east-west across the Swat Valley, separates regions...
Differential compaction mechanism for earth fissures near Casa Grande, Arizona
R.C. Jachens, T.L. Holzer
1982, Geological Society of America Bulletin (93) 998-1012
Precise gravity measurements indicate that earth fissures or tension cracks caused by ground-water withdrawal within a 10-km2 area southeast of Casa Grande, Arizona, are associated with relief on the buried interface between the alluvial aquifer and underlying bedrock. All of the fissure zones; which...
Incorporation of prior information on parameters into nonlinear regression groundwater flow models: 1. Theory
Richard L. Cooley
1982, Water Resources Research (18) 965-976
Prior information on the parameters of a groundwater flow model can be used to improve parameter estimates obtained from nonlinear regression solution of a modeling problem. Two scales of prior information can be available: (1) prior information having known reliability (that is, bias and random error structure) and (2) prior...
Periodic climate change on Mars: Review of evidence and effects on distribution of volatiles
M. H. Carr
1982, Icarus (50) 129-139
The polar regions of Mars preserve, in both their layering and their topography, a record of recent climate changes. Because of the coincidence of the growth of the northern seasonal cap with global dust storms, dust may be currently accumulating on...
Blake Plateau: Control of Miocene sedimentation patterns by large-scale shifts of the Gulf Stream axis
P.R. Pinet, P. Popenoe
1982, Geology (10) 257-259
The distribution of buried channel networks within Cenozoic sequences of the Blake Plateau and their correlation with global sea-level oscillations indicate that the Gulf Stream axis shifted landward against the Florida-Hatteras Slope during sea-level high-stands and seaward across the central Blake Plateau during...
An analysis of input errors in precipitation-runoff models using regression with errors in the independent variables
Brent M. Troutman
1982, Water Resources Research (18) 947-964
Errors in runoff prediction caused by input data errors are analyzed by treating precipitation-runoff models as regression (conditional expectation) models. Independent variables of the regression consist of precipitation and other input measurements; the dependent variable is runoff. In models using erroneous input data, prediction errors are inflated and estimates of...
Comparison of techniques for estimating annual lake evaporation using climatological data
M.E. Andersen, H.E. Jobson
1982, Water Resources Research (18) 630-636
Mean annual evaporation estimates were determined for 30 lakes by use of a numerical model (Morton, 1979) and by use of an evaporation map prepared by the U.S. Weather Service (Kohler et al., 1959). These estimates were compared to the reported value of evaporation determined from measurements on each lake....
The solubilities of calcite, aragonite and vaterite in CO2-H2O solutions between 0 and 90°C, and an evaluation of the aqueous model for the system CaCO3-CO2-H2O
Niel Plummer, Eurybiades Busenberg
1982, Geochimica et Cosmochimica Acta (46) 1011-1040
Calculations based on approximately 350 new measurements (CaT-PCO2) of the solubilities of calcite, aragonite and vaterite in CO2-H2O solutions between 0 and 90°C indicate the following values for the log of the equilibrium constants KC, KA, and KV respectively, for the reaction CaCO3(s) = Ca2+ + CO2−3: <img...
A population model of the lizard Uta stansburiana, in southern Nevada
Frederick B. Turner, Phil A. Medica, K. W. Bridges, R. I. Jennrich
1982, Ecological Monographs (52) 243-259
Population densities, reproduction, and survival of the lizard Uta stansburiana were measured at the Nevada Test Site in southern Nevada, USA, between 1964 and 1974. These data were used to develop a model of the population dynamics of this species. Results of irrigation experiments in 0.4—ha enclosures near Mercury, Nevada,...
Margaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.
K. J. Wenrich, P.J. Modreski, R. A. Zielinski, J. L. Seeley
1982, American Mineralogist (67) 1273-1289
Margaritasite, (Cs,K,H3O)2(UO2)2V2O8.nH2O (where Cs > K, H3O and n approx 1), a 10.514, b 8.425, c 7.25 A, beta 106.01o, P21/a, Z = 2, is a newly recognized uranium ore mineral named for the Margaritas deposit, Pena Blanca uranium district, Chihuahua, Mexico, at which it was discovered. A Cs-rich analogue...
Accumulation rates of Th-230, Pa-231, and some transition metals on the Bermuda Rise
M.P. Bacon, J.N. Rosholt
1982, Geochimica et Cosmochimica Acta (46) 651-666
Measurements of 238U, 234U, 230Th, 232Th, 231Pa, Mn, Fe, Co, Ni, Cu, and Zn were made on 23 samples from core GPC-5, a 29-m giant piston core from a water depth of 4583 m on the northeastern Bermuda Rise (33°41.2′N, 57°36.9′W). This area is characterized by rapid deposition of sediment transported by abyssal currents. Unsupported 230Th...
Stability of βMnOOH and manganese oxide deposition from springwater
J.D. Hem, C. E. Roberson, Reba B. Fournier
1982, Water Resources Research (18) 563-570
Beta MnOOH is precipitated preferentially (with respect to Mn3O4) at temperatures near O°C when Mn2+ is oxidized in aerated aqueous solutions. Upon aging in solutions open to the atmosphere a slurry of βMnOOH tends to disproportionate to form MnO2 and Mn2+. In such aged solutions, Mn2+ and H+ activities can be constant, and both...
The effect of natural weathering on the chemical and isotopic compositions of biotites
Norbert Clauer, J. R. O’Neil, C. Bonnot-Courtois
1982, Geochimica et Cosmochimica Acta (46) 1755-1762
The effect of progressive natural weathering on the isotopic (Rb-Sr, K-Ar, δD, δ18O) and chemical (REE, H2O+) compositions of biotite has been studied on a suite of migmatitic biotites from the Chad Republic. During the early stages of weathering the Rb-Sr system is strongly affected, the hydrogen and oxygen isotope compositions...
The oxygen isotope composition of granitoid and sedimentary rocks of the southern Snake Range, Nevada
D. E. Lee, I. Friedman, J.D. Gleason
1982, Contributions to Mineralogy and Petrology (79) 150-158
Six diverse intrusive igneous types are exposed as discrete outcrops within an area of 900 km2 in the southern Snake Range, White Pine County, Nevada. The previously recognized variety among these igneous types is reflected in the wide range of ??18O values (-1.1 to 13.4 permil) found in these rocks....
Application of modulus degradation model of clays
A.T.F. Chen
1982, Journal of the Geotechnical Engineering Division, ASCE (108) 1203-1214
A degradation model is applied in conjunction with different soil models and stress-strain relations to site response analyses during earthquakes. To evaluate the effects of degradation, computations on two clay deposits subjected to both high and low-level input excitations are conducted. In addition, modulus degradation with or without shear strength...
Worth of geophysical data in natural- disaster- insurance rate setting.
E. D. Attanasi, M.R. Karlinger
1982, Journal of Applied Meteorology and Climatology (21) 453-460
Insurance firms that offer natural-disaster insurance base their rates on available information. The benefits from collecting additional data and incorporating this information to improve parameter estimates of probability distributions that are used to characterize natural-disaster events can be determined by computing changes in premiums as a function of additional data....
Geochemical indices of fine sediment transport, northwest Gulf of Mexico
C. W. Holmes
1982, Journal of Sedimentary Petrology (52) 307-321
The 210 Pb distribution, the clay mineralogy distribution, and the distribution of three trace metals, barium, lead, and manganese, in the sediments of the south Texas shelf are related to the dynamics of the sedimentary transport process. 210 Pb, whose concentration is time dependent, defines three loci...
Late Pleistocene- Holocene transgressive sedimentation in deltaic and non-deltaic areas of the northeastern Bering epicontinental shelf.
C.H. Nelson
1982, Geologie en Mijnbouw (61) 5-18
The distribution of late Pleistocene and Holocene surface sediments on the northern Bering Seafloor is patchy and dependent upon locations of seafloor bedrock and pre-late Pleistocene glacial debris, late Holocene river sediment influx, and modern strong bottom currents. Seafloor vibracores and high-resolution profiles record two different sedimentary environments in the...
Identification of the Holocene-Pleistocene boundary in the Bering Sea by diatoms.
J.G. Baldauf
1982, Boreas (11) 113-118
The modern diatom flora from surface sediment of the Navarin Basin region of the Bering Sea is dominated by Denticulopsis seminae and Nitzschia oceanica. D. seminae, a north boreal species, is most abundant in the deeper waters of the slope-basin regions, whereas N. oceanica, an Arctic species associated with ice...
Numerical models of hydrothermal circulation for the intrusion zone at an ocean ridge axis
P.L. Patterson, R.P. Lowell
Kent A. Fanning, Frank T. Manheim, editor(s)
1982, Book chapter, The dynamic environment of the ocean floor
No abstract available....
The impact of entrainment and impingement on fish populations in the Hudson River estuary: Volume II: Impingement impact analyses, evaluations of alternative screening devices, and critiques of utility testimony relating to density-dependent growth, the age-composition of the striped bass Spawning stock, and the LMS Real-Time Life Cycle Model
L.W. Barnthouse, W. Van Winkle, J. Golumbek, G. F. Cada, C.P. Goodyear, S.W. Christensen, J.B. Cannon, D.W. Lee
1982, Report
No abstract available at this time...
Volcanoes
Robert I. Tilling
1982, Report
Volcanoes destroy and volcanoes create. The catastrophic eruption of Mount St. Helens on May 18, 1980, made clear the awesome destructive power of a volcano. Yet, over a time span longer than human memory and record, volcanoes have played a key role in forming and modifying the planet upon which...
