Ground water for oil-shale development, Piceance Basin, Colorado
W.M. Alley
1983, Ground Water (21) 456-464
Vast deposits of oil shale are contained in the Piceance basin in northwestern Colorado. The basin may contain as much as 40 million acre-feet of stored water associated with these deposits, much of which may have to be drained for mining. Yet, most analyses of...
Old Crow tephra: A new late Pleistocene stratigraphic marker across north-central Alaska and western Yukon Territory
J.A. Westgate, T. D. Hamilton, M.P. Gorton
1983, Quaternary Research (19) 38-54
Old Crow tephra is the first extensive Pleistocene tephra unit to be documented in the northwestern part of North America. It has a calc-alkaline dacitic composition with abundant pyroxene, plagioclase, and FeTi oxides, and minor hornblende, biotite, apatite, and zircon. Thin, clear, bubble-wall fragments are the dominant type of glass...
Structure and petrology of the La Perouse gabbro intrusion, Fairweather Range, southeastern Alaska
R. A. Loney, G. R. Himmelberg
1983, Journal of Petrology (24) 377-423
The middle Tertiary La Perouse gabbro intrusion occurs in a Mesozoic metamorphic terrane (Chugach terrane) in the Fairweather Range, southeastern Alaska. The intrusion is 12 km wide and 27 km long, and has an exposed cumulate layering thickness of about 6000 m. The contact consists of biotite and hornblende...
Use of reflectance spectra of native plant species for interpreting airborne multispectral scanner data in the East Tintic Mountains, Utah
N.M. Milton
1983, Economic Geology (78) 761-769
Representative spectra from three plant species were used to interpret the color components on a color ratio composite image. Most of the vegetation unit coincided with an altered rock unit, but many altered areas were not within the vegetation unit....
Statistical averaging of marine magnetic anomalies and the aging of oceanic crust
R.J. Blakely
1983, Journal of Geophysical Research Solid Earth (88) 2289-2296
Visual comparison of Mesozoic and Cenozoic magnetic anomalies in the North Pacific suggests that older anomalies contain less short-wavelength information than younger anomalies in this area. To test this observation, magnetic profiles from the North Pacific are examined from crust of three ages: 0–2.1, 29.3–33.1, and 64.9–70.3 m.y, B.P. For...
Subdivision of the Mg-suite noritic rocks into Mg-gabbronorites and Mg-norites
O.B. James, M.K. Flohr
1983, Journal of Geophysical Research Solid Earth (88) A603-A614
Mg-suite noritic rocks can be divided into two groups, the Mg-gabbronorites and the Mg-norites. The rocks of these groups differ in ratios of high-Ca pyroxene to total pyroxene, compositions of pyroxene and plagioclase, assemblages of Ti-, Nb-, and Zr-bearing minerals, compositions of chrome spinel, bulk-rock Ti/Sm and Sc/Sm, and measured...
Harmotome in a basaltic, volcaniclastic sandstone from a lacustrine deposit near Kirkland Junction, Yavapai County, Arizona
Richard A. Sheppard, Arthur J. Gude III
1983, Clays and Clay Minerals (31) 57-59
Harmotome, probably the most common of the barium-rich zeolites, has been reported from a variety of metamorphic and igneous rocks throughout the world (Deer et al., 1963). Harmotome, however, seems to be a rare authigenic constituent in sedimentary rocks, and its most common occurrence apparently is in deep-sea sediments where...
Speculation on martian north polar wind circulation and the resultant orientations of polar sand dunes
A. W. Ward, K.B. Doyle
1983, Icarus (55) 420-431
Dunes in the Martian north polar erg show two dominant orientations. When seen at frost cap minimum, dunes north of 80°N record east winds, dunes south of 80°N record west winds. Many of the transverse dunes are considered to be reversing...
Nucleation and growth of strike slip faults in granite
P. Segall, D.P. Pollard
1983, Journal of Geophysical Research Solid Earth (88) 555-568
Fractures within granodiorite of the central Sierra Nevada, California, were studied to elucidate the mechanics of faulting in crystalline rocks, with emphasis on the nucleation of new fault surfaces and their subsequent propagation and growth. Within the study area the fractures form a single, subparallel array which strikes N50°–70°E and...
Variable tolerance to copper in two species from San Francisco Bay
Samuel N. Luoma, D.J. Cain, K. Ho, A. Hutchinson
1983, Marine Environmental Research (10) 209-222
In static toxicity experiments, tolerance to soluble Cu of the bivalve, Macoma balthica, and the copepod, Acartia clausi, varied substantially among populations sampled within San Francisco Bay. Intraspecific tolerance differed ten-fold or more for both species over relatively small distances, suggesting geographical isolation of populations is not a prerequisite for...
Euler-Lagrangian computation for estuarine hydrodynamics
Ralph T. Cheng
1983, Conference Paper, Numerical Methods in Laminar and Turbulent Flow, Proceedings of the International Conference
The transport of conservative and suspended matter in fluid flows is a phenomenon of Lagrangian nature because the process is usually convection dominant. Nearly all numerical investigations of such problems use an Eulerian formulation for the convenience that the computational grids are fixed in space and because the vast majority...
Use of multispectral scanner images for assessment of hydrothermal alteration in the Marysvale, Utah, mining area.
M. H. Podwysocki, D. B. Segal, M. J. Abrams
1983, Economic Geology (78) 675-687
Airborne multispectral scanner. A color composite image was constructed using the following spectral band ratios: 1.6/2.2 mu m, 1.6/0.48 mu m, and 0.67/1.0 mu m. The color ratio composite successfully distinguished most types of altered rocks from unaltered rocks; further division of altered rocks into ferric oxide-rich and -poor types....
Tectonic uplift of a middle Wisconsin marine platform near the Mendocino triple junction California
R. J. McLaughlin, K. R. Lajoie, D. H. Sorg, S.D. Morrison, J. A. Wolfe
1983, Geology (11) 35-39
An uplifted wave-cut marine platform eroded across bedrock of the Franciscan Complex at Point Delgada, northern California, is overlain by 0.5 to 5 m of wave-worked pea gravel, which is in turn directly overlain by fluvial gravel and silt deposited as alluvial fans....
40Ar/39Ar and U-Th-Pb dating of separated clasts from the Abee E4 chondrite
D.D. Bogard, D.M. Unruh, M. Tatsumoto
1983, Earth and Planetary Science Letters (62) 132-146
Determinations of40Ar/39Ar and U-Th-Pb are reported for three clasts from the Abee (E4) enstatite chondrite, which has been the object of extensive consortium investigations. The clasts give40Ar/39Ar plateau ages and/or maximum ages of 4.5 Gy, whereas two of the clasts give...
Quaternary geology of the Rhode Island inner shelf
S. W. Needell, C. J. O’Hara, H.J. Knebel
1983, Marine Geology (53) 41-53
Five sedimentary units and three erosional unconformities identified in high-resolution seismic-reflection profiles reveal the stratigraphic framework and Quaternary history of the inner continental shelf south of Narragansett Bay, Rhode Island. Late Tertiary to early Pleistocene rivers eroded the pre-Mesozoic bedrock and the Upper Cretaceous to lower Tertiary coastal plain and...
Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion
John D. Bredehoeft, Richard A. Young
1983, Water Resources Research (19) 1111-1121
In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what...
Iron disulfide minerals and the genesis of roll-type uranium deposits
R. L. Reynolds, M. B. Goldhaber
1983, Economic Geology (78) 105-120
FeS 2 minerals in host rocks for deposits that contain fossil vegetal (organic) matter differ in abundance, distribution, texture, and sulfur isotopic ratios from FeS 2 minerals in host rocks for deposits that do not contain fossil vegetal matter. In three South Texas deposits lacking such organic matter, preore FeS 2 is dominantly euhedral pyrite which...
Faulting arrested by control of ground-water withdrawal in Houston, Texas
T. Holzer, R.K. Gabrysch, E.R. Verbeek
1983, Earthquake Information Bulletin (USGS) (15) 204-209
More than 86 historically active faults with an aggregate length of 150 miles have been identified within and adjacent to the Houston, Texas, metropolitan area. Although scarps of these faults grow gradually and without causing damaging earthquakes, historical fault offset has cost millions of dollars in damage to houses and...
A short-pulse electromagnetic transponder for hole-to-hole use
David L. Wright, Raymond D. Watts, Erik Bramsoe
1983, IEEE Transactions on Geoscience and Remote Sensing (GE-22) 720-725
We have made hole-to-hole observations through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. We found that the transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to...
Fission track dating of kimberlitic zircons
S.E. Haggerty, E. Raber, C. W. Naeser
1983, Earth and Planetary Science Letters (63) 41-50
The only reliable method for dating kimberlites at present is the lengthy and specialized hydrothermal procedure that extracts206Pb and238U from low-uranium zircons. This paper describes a second successful method by fission track dating of large single-crystal zircons, 1.0–1.5 cm in dimension. The use of large crystals overcomes the limitations imposed...
Selective concentration of cesium in analcime during hydrothermal alteration, Yellowstone National Park, Wyoming
T. E. C. Keith, J. M. Thompson, R. E. Mays
1983, Geochimica et Cosmochimica Acta (47) 795-804
Chemical and mineralogical studies of fresh and hydrothermally altered rhyolitic material in Upper and Lower Geyser Basins, Yellowstone National Park, show that all the altered rocks are enriched in Cs and that Cs is selectively concentrated in analcime. The Cs content of unaltered rhyolite lava flows, including those from which...
Progressive changes in the morphology of fluvial terraces and scarps along the Rappahannock River, Virginia.
Steven M. Colman
1983, Earth Surface Processes and Landforms (8) 201-212
Progressive geomorphic changes in the flight of fluvial terraces along the Rappahannock River, Virginia, provide a framework for analysing the effect of time on landforms. Indices of terrace preservation, especially drainage densities and area to perimeter ratios, show systematic changes with terrace age. Higher scarps tend to have steeper slopes...
Storm-controlled oblique dunes of the Oregon coast
R. E. Hunter, B. M. Richmond, T. R. Alpha
1983, Geological Society of America Bulletin (94) 1450-1465
The large (mean height 25 m, spacing 300 m), relatively straight-crested dunes of the central Oregon coast migrate an average of 3.8 m/yr toward an azimuth of 26°. The dunes are transverse to the strong, south-southwesterly winter storm winds that are responsible for...
A quantitative comparison of Soil Development in four climatic regimes
J.W. Harden, E. M. Taylor
1983, Quaternary Research (20) 342-359
A new quantitative Soil Development Index based on field data has been applied to chronosequences formed under different climatic regimes. The four soil chronosequences, developed primarily on sandy deposits, have some numeric age control and are located in xeric-inland (Merced, Calif.), xeric-coastal (Ventura, Calif.), aridic (Las Cruces, N. Mex.), and...
Determination of chloride in geological samples by ion chromatography
Stephen A. Wilson, Carol A. Gent
1983, Analytica Chimica Acta (148) 299-303
Samples of silicate rocks are prepared by sodium carbonate fusion and then treated by ion chromatography. The method was tested for geological standards with chloride concentration between 0.003 and 3%. Observed chloride concentrations comparedd favorably with literature values. The relative standard deviation and detection limit for the method were 8%...
