Origin of coffinite in sedimentary rocks by a sequential adsorption-reduction mechanism.
Martin B. Goldhaber, B. S. Hemingway, A. Mohagheghi, R. L. Reynolds, H. R. Northrop
1987, Bulletin de Mineralogie (110) 131-144
Coffinite is the dominant ore mineral in the V-U ores of the Tony-M mine in the Henry Mts mineral belt of the Colorado Plateau. This orebody was formed at a density-stratified solution interface between uranyl-ion-bearing meteoric water and a saline fluid which was locally reducing. The localization of U at...
Changes in the H O Ar isotope composition of clays during retrograde alteration
M.R. Wilson, T.K. Kyser, H. H. Mehnert, J. Hoeve
1987, Geochimica et Cosmochimica Acta (51) 869-878
K-Ar ages of illite alteration associated with Middle Proterozoic Athabasca unconformity-type U deposits in Saskatchewan range from 414 to 1493 Ma. The K-Ar ages correlate with water contents and δD values such that illites with young K-Ar ages have δD values as low as −169 and water contents as high...
Reassessment of the volkonskoite-chromian smectite nomenclature problem.
Eugene E. Foord, Harry C. Starkey, Joseph E. Taggart Jr., Daniel R. Shawe
1987, Clays and Clay Minerals (35) 139-149
The name volkonskoite was first used in 1830 to describe a bright blue-green, chromium-bearing clay material from the Okhansk region, west of the Ural Mountains, U.S.S.R. Since that time, the name has been applied to numerous members of the smectite group of clay minerals, although the reported chromium content has...
Mineralogical basis for the interpretation of multi-element (ICP-AES), oxalic acid, and aqua regia partial digestions of stream sediments for reconnaissance exploration geochemistry
S. E. Church, E. L. Mosier, J. M. Motooka
1987, Journal of Geochemical Exploration (29) 207-233
We have applied partial digestion procedures, primarily oxalic acid and aqua regia leaches, to several regional geochemical reconnaissance studies carried out using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) analytical methods. We have chosen to use these two acids because the oxalic...
Geochemical studies in the Indian Pass and Picacho Peak Bureau of Land Management Wilderness study areas, imperial county, Southern California
D. B. Smith, B. R. Berger, R. M. Tosdal
1987, Journal of Geochemical Exploration (28) 479-494
The U.S. Geological Survey has conducted geochemical studies in the Indian Pass (CDCA-355), 124 km2, and Picacho Peak (CDCA-355A), 23 km2, Wilderness Study Areas (WSA's) as part of a program to evaluate the mineral resource potential of designated areas in the California Desert Conservation Area. These two WSA's are of...
Conodont color and textural alteration: An index to regional metamorphism, contact metamorphism, and hydrothermal alteration
V.A. Rejebian, A. G. Harris, J.S. Huebner
1987, Geological Society of America Bulletin (99) 471-479
Experimental and field data are used to extend the utility of conodonts as semi-quantitative thermal indices into the regimes of regional and contact metamorphism, as well as hydrothermal alteration. An Arrhenius plot of data from induced conodont color alteration by pyrolysis in air at 1 atm was used to generate...
Pressure-composition relations for coexisting gases and liquids and the critical points in the system NaCl-H2O at 450, 475, and 500°C
Robert J. Rosenbauer, James L. Bischoff
1987, Geochimica et Cosmochimica Acta (51) 2349-2354
Pressure-temperature-composition (P, T, x) relations for the co-existing vapor and liquid phases in the system NaCl-H2O were determined experimentally at 450, 475, and 500°C. Data for each isotherm includeP-x relations near the critical point and extend to the three-phase assemblage vapor-liquid-halite on the vapor side. On the liquid side the P-x data range from the...
Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.
C. Gene Whitney, H. R. Northrop
1987, American Journal of Science (287) 353-382
The Westwater Canyon Member of the Upper Jurassic Morrison Formation is a relatively homogeneous, hydrologically continuous 100-m-thick sequence of massive fluvial sandstone, bounded above and below by relatively heterogeneous, hydrologically discontinuous units and has served as a primary conduit for fluids within this stratigraphic interval. Patterns of mineral-fluid reactions suggest...
Slab pull and the seismotectonics of subducting lithosphere
William Spence
1987, Reviews of Geophysics (25) 55-69
This synthesis links many seismic and tectonic processes at subduction zones, including great subduction earthquakes, to the sinking of subducted plate. Earthquake data and tectonic modeling for subduction zones indicate that the slab pull force is much larger than the ridge push force. Interactions between the forces that drive and...
Ecological aspects of microorganisms inhabiting uranium mill tailings
C.L. Miller, E. R. Landa, D.M. Updegraff
1987, Microbial Ecology (14) 141-155
Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but...
The crustal structure of the axis of the Great Valley, California, from seismic refraction measurements
W.S. Holbrook, Walter D. Mooney
1987, Tectonophysics (140) 49-63
In 1982 the U.S. Geological Survey collected six seismic refraction profiles in the Great Valley of California: three axial profiles with a maximum shot-to-receiver offset of 160 km, and three shorter profiles perpendicular to the valley axis. This paper presents the results of two-dimensional raytracing and synthetic seismogram modeling of...
Modes of development of slope canyons and their relation to channel and levee features on the Ebro sediment apron, off-shore northeastern Spain
S. O'Connell, William B. F. Ryan, W. R. Normark
1987, Marine and Petroleum Geology (4)
Six submarine slope canyons in an area of the northwestern Mediterranean, offshore from the Ebro River and Delta, were surveyed with bathymetric swathmapping (SeaBeam) and mid-range side-looking sonar (SeaMARC I). All of the canyons have slightly winding paths with concave-upwards gradients that are relatively steep shallower than 1,200 m. Two...
The mobilization of aluminum in a natural soil system: Effects of hydrologic pathways
Isabelle M. Cozzarelli, Janet S. Herman, Roderic A. Parnell Jr.
1987, Water Resources Research (23) 859-874
A two-component soil water flow model was used in conjunction with an equilibrium speciation model WATEQF to study aluminum mobility in soils of a forested watershed, White Oak Run, in the Shenandoah National Park, Virginia. Soil solution samples, taken from the O, E, B, C1, and C2horizons, were collected from...
Labeling Projections on Published Maps
John P. Snyder
1987, American Cartographer (14) 21-27
To permit accurate scaling on a map, and to use the map as a source of accurate positions in the transfer of data, certain parameters - such as the standard parallels selected for a conic projection - must be stated on the map. This information is often missing on published...
FUTURE APPLICATIONS OF EXPERT SYSTEMS FOR THE EVALUATION OF ENERGY RESOURCES.
B.M. Miller
1987, Conference Paper, Society of Petroleum Engineers of AIME, (Paper) SPE
The loss of professional experience and expertise in the domain of the earth sciences may prove to be one of the most serious outcomes of the boom-and-bust cyclic nature of the volatile energy and mining industries. Promising new applications of powerful computer systems, known as 'expert systems' or 'knowledge-based systems',...
DISCHARGE AND DEPTH BEHIND A PARTIALLY BREACHED DAM.
Cheng-lung Chen
1987, Conference Paper
The role that the velocity-distribution correction factor plays in the determination of the flood discharge and corresponding flow depth behind a partially breached dam is investigated. Assumption of a uniformly progressive flow for an established dam-break flood in a rectangular channel of infinite extent leads to the formulation of a...
Ingestion of plastic debris by Laysan albatrosses and wedge-tailed shearwaters in the Hawaiian Islands
D.M. Fry, S.I. Fefer, L. Sileo
1987, Marine Pollution Bulletin (18) 339-343
Surveys of Laysan Albatross and Wedge-tailed Shearwaters on Midway and Oahu Island, Hawaii, identified a high proportion of birds with plastic in the upper gastrointestinal tract, representing hazards to the health of adult birds and their chicks. Fifty Laysan Albatross chicks were examined for plastic items lodged within the upper...
Isotopic composition of pyrite: Relationship to organic matter type and iron availability in some North American cretaceous shales
D. L. Gautier
1987, Chemical Geology: Isotope Geoscience Section (65) 293-303
The S isotope composition of pyrite in Cretaceous shales from the Western Interior of North America is related to organic C abundance, kerogen type and Fe availability. Both calcareous and noncalcareous rocks show a correlation between S and C, but noncalcareous...
Dynamics of Mojave Desert shrub assemblages in the Panamint Mountains, California.
Robert Webb, John W. Steiger, Raymond M. Turner
1987, Ecology (68) 478-490
We studied shrub communities in the Panamint Mountains of the Mojave Desert to determine whether vegetational changes after disturbance can be characterized as succession according to modern successional theory. We found, on a variety of disturbed and undisturbed sites, that the rate of change was a function of the type...
Wolfcampian brachiopods from the Bird Spring Group, Wamp Spring area, Las Vegas Range, Clark County, Nevada
P. C. Mills, R.L. Langenheim Jr.
1987, Journal of Paleontology (61) 32-55
The Wamp Spring section of the Bird Spring Group consists of approximately 1,600 feet of carbonate rocks subdivided into a basal platy limestone member, lower cliff-forming member, and upper cliff-forming member. Triticites, Schwagerina, and Schubertella kingi in the platy limestone member indicate an early Wolfcampian age. Schwagerina, Schubertella...
LEACHATE MIGRATION FROM A SOLID WASTE DISPOSAL FACILITY NEAR BISCAYNE NATIONAL PARK, SOUTH FLORIDA.
Bradley G. Waller, James L. Labowski
1987, Conference Paper
Leachate from the Dade County Solid Waste Disposal Facility (SWDF) is migrating to the east (seaward) and to the south from the currently active disposal cell. Water levels and ground-water flow directions are strongly influenced by water-management practices. The SWDF is constructed over the salt-intruded part of the highly transmissive...
Provenance studies by fission-track dating of zircon-etching and counting procedures
N. D. Naeser, P.K. Zeitler, C. W. Naeser, P.F. Cerveny
1987, International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements (13) 121-126
In sedimentary rocks that have not been heated to high enough temperatures to anneal fission tracks in zircon (greater than ≈ 160°C), fission-track ages of individual detrital zircon grains provide valuable information about the source rocks eroded to form the sediments. The success of such studies depends, however, on the...
Volcanism and massive sulfide formation at a sedimented spreading center, Escanaba Trough, Gorda Ridge, northeast Pacific
J. L. Morton, M.L. Holmes, R.A. Koski
1987, Geophysical Research Letters (14) 769-772
Seismic-reflection profiles over the sediment-filled Escanaba Trough at the southern Gorda Ridge reveal a series of volcanic centers that pierce the sediment. The volcanic edifices are 3 to 6 km in diameter and are spaced at 15 to 20 km intervals along the axis of the...
FeTi oxide mineralogy and the origin of normal and reverse remanent magnetization in dacitic pumice blocks from Mt. Shasta, California
C.A. Lawson, Gordon L. Nord Jr., D.E. Champion
1987, Physics of the Earth and Planetary Interiors (46) 270-288
Detailed mineralogical analyses and rock magnetic experiments have made it possible to directly identify the FeTi oxide phases responsible for the normal and reverse magnetic components of two dacitic pumice blocks from Mt. Shasta, California. Both samples contain a normal component carried by 100 ??m size multi-domain (MD) titanomagnetite (Usp11-24)....
Fluorescence spectral analysis of resinite macerals from coals of the Hanna Formation, Wyoming, U.S.A.
S.C. Teerman, J.C. Crelling, G.B. Glass
1987, International Journal of Coal Geology (7) 315-334
Flourescence spectral analysis indicates that resinite macerals from Tertiary Hanna Formation coals (Hanna Coal Field, southcentral Wyoming, U.S.A.) can be separated into five distinct groups. The first resinite group fluoresces a a medium green (in blue light); its average spectral maximum...
