Clarification of the Hashin-Shtrikman bounds on the effective elastic moduli of polycrystals with hexagonal, trigonal, and tetragonal symmetries
J.P. Watt, L. Peselnick
1980, Journal of Applied Physics (51) 1525-1531
Bounds on the effective elastic moduli of randomly oriented aggregates of hexagonal, trigonal, and tetragonal crystals are derived using the variational principles of Hashin and Shtrikman. The bounds are considerably narrower than the widely used Voigt and Reuss bounds. The Voigt-Reuss-Hill average lies within the Hashin-Shtrikman bounds in nearly all...
Inland (non-tidal) wetland mapping.
W.R. Steward, V. Carter, P. D. Brooks
1980, Photogrammetric Engineering and Remote Sensing (46) 617-628
The US Geological Survey has prepared three experimental wetland maps for the Auburndale, Florida 1:24,000-scale quadrangle. Wetland classes and boundaries were interpreted from quad centered high altitude color infrared and superwide black and white panchromatic photographs onto a black and white orthophoto base map made from a color infrared photograph....
Multiple ice flow directions during the Fraser Glaciation in the lower Skagit River drainage, northern Cascade Range, Washington
Paul L. Heller
1980, Arctic and Alpine Research (12) 299-308
Stratigraphic mapping and pebble-count data suggest that ice flowed in three different directions in the lower Skagit drainage of the northern Cascade Range during the Fraser Glaciation (∼ 10K to 20K BP). Glacier reconstructions suggest that till exposed at one site in the lower Skagit Valley was deposited by a...
Scaling variables and interpretation of eigenvalues in principal component analysis of geologic data
A.T. Miesch
1980, Journal of the International Association for Mathematical Geology (12) 523-538
The dominant feature distinguishing one method of principal components analysis from another is the manner in which the original data are transformed prior to the other computations. The only other distinguishing feature of any importance is whether the eigenvectors of the inner product-moment of the transformed data matrix are taken...
Dissolution and analysis of amorphous silica in marine sediments
D.W. Eggimann, F.T. Manheim, P.R. Betzer
1980, Journal of Sedimentary Petrology (50) 215-225
The analytical estimation of amorphous silica in selected Atlantic and Antarctic Ocean sediments, the U.S.G.S. standard marine mud (MAG-1), A.A.P.G. clays, and samples from cultures of a marine diatom, Hemidiscus, has been examined. Quantitative recovery of sedimentary amorphous silica was achieved by reacting...
Evaluation of multispectral middle infrared aircraft images for lithologic mapping in the East Tintic Mountains, Utah
A.B. Kahle, L. C. Rowan
1980, Geology (8) 234-239
Six channels of multispectral middle infrared (8 to 14 μrn) aircraft scanner data were acquired over the East Tintic mining district, Utah. This area has high relief and moderate vegetation and consists mainly of Tertiary silicic igneous rocks and Paleozoic quartzite and carbonate...
Kinetic model for the short-term dissolution of a rhyolitic glass
A. F. White, H.C. Claassen
1980, Chemical Geology (28) 91-109
Aqueous dissolution experiments with the vitric phase of a rhyolitic tuff were performed at 25??C and constant pH in the range 4.5-7.5. Results suggest interchange of aqueous hydrogen ions for cations situated both on the surface and within the glass. At time intervals from 24 to 900 hr., dissolution kinetics...
Chemical mass-wasting of the northern Yucatan Peninsula by groundwater dissolution
B.B. Hanshaw, W. Back
1980, Geology (8) 222-224
The northern part of the Yucatan Peninsula is a relatively flat, low-lying carbonate terrane with no geomorphic expressions of stream channels. It is estimated that mean annual recharge to the groundwater system is 150 mm. For the 65,500 km2 study area, mean annual discharge (equivalent to recharge) is 9.8 × 109 m3,...
Shallow, low-permeability reservoirs of northern Great Plains: Assessment of their natural gas resources.
Dudley D. Rice, George W. Shurr
1980, American Association of Petroleum Geologists Bulletin (64) 969-987
Major resources of natural gas are entrapped in low-permeability, low-pressure reservoirs at depths less than 4,000 ft (1,200 m) in the northern Great Plains. This shallow gas is the product of the immature stage of hydrocarbon generation and is referred to as biogenic gas. Prospective low-permeability, gas-bearing reservoirs range in...
Direct computation of the sensible heat flux
K. Watson
1980, Geophysical Research Letters (7) 616-618
An algorithm to determine the sensible heat flux from simple field measurements (wind speed, air and ground temperatures) has been developed. It provides a direct solution, in parametric form, which can be displayed graphically or tabularly. This method has an advantage over the previous iterative solution...
Results and assessment of uranium series dating of vertebrate fossils from Quaternary alluvium in Colorado
Barney J. Szabo
1980, Arctic and Alpine Research (11) 95-100
An average uranium-series age of 102,000 ± 14,000 yr for bones from Louviers Alluvium, near Denver, Colorado, is compatible with the inferred geologic age of from 120,000 to 150,000 yr. A uranium-series date of about 190,000 yr for a bone from Slocum Alluvium, near Canon City, Colorado, is consistent with...
The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.
R. A. Zielinski, D. A. Lindsey, J.N. Rosholt
1980, Chemical Geology (29) 139-162
The distribution and mobility of uranium in a diagenetically altered, 8 Ma old tuff in the Keg Mountain area, Utah, are modelled in this study. The modelling represents an improvement over similar earlier studies in that it: (1) considers a large number of samples (76) collected with good geologic control...
Geology and biology of Oceanographer submarine canyon.
P. C. Valentine, J. R. Uzmann, R.A. Cooper
1980, Marine Geology (38) 283-312
Santonian beds more than 100 m thick are the oldest rocks collected from the canyon. Quaternary silty clay veneers the canyon walls in many places and is commonly burrowed by benthic organisms that cause extensive erosion of the canyon walls, especially in the depth zone (100-1300 m) inhabited by the...
Stress measurements at depth in the vicinity of the San Andreas fault. Implications for the magnitude of shear stress at depth
M.D. Zobach, H. Tsukahara, S. Hickman
1980, Journal of Geophysical Research Solid Earth (85) 6157-6173
Using the hydraulic fracturing technique, we have made a systematic series of in situ stress measurements in wells drilled near the San Andreas fault. In an attempt to provide constraints for the magnitude of shear stress on the San Andreas fault at depth we have measured both the variation of...
Tertiary climates and floristic relationships at high latitudes in the northern hemisphere
J. A. Wolfe
1980, Palaeogeography, Palaeoclimatology, Palaeoecology (30) 313-323
During the Paleocene and Eocene, climates were characterized by a low mean annual range of temperature (a maximum of 10-15??C), a moderate to high mean annual temperature (10-20??C), and abundant precipitation; strong broad-leaved evergreen vegetation extended to almost lat. 60??N during the Paleocene and to well above 61??N during the...
Sr isotopic fractionation in Ca-Al inclusions from the Allende meteorite
P. J. Patchett
1980, Nature (283) 438-441
True relative Sr isotopic compositions, determined by double spiking on Ca-Al inclusions from the Allende meteorite show up to 1.5??? per mass unit mass fractionation relative to the Earth and bulk chondrites. All abnormal inclusions are light-isotope enriched. A lack of isotopically heavy Sr in inclusions would place constraints on...
Lithospheric loading by the 1896 Riku-u earthquake, northern Japan: Implications for plate flexure and asthenospheric rheology
W. Thatcher, T. Matsuda, T. Kato, J. B. Rundle
1980, Journal of Geophysical Research Solid Earth (85) 6429-6435
Under favorable circumstances the time-dependent aseismic deformation resulting from the loading of the lithosphere by the stress drop of large dip slip earthquakes can be used to determine both the effective elastic plate thickness and the asthenospheric viscosity. The deformation has several similarities with the deflection of the lithosphere by...
(π−1) → (π−1), (π−1) emission spectra of chlorofluorobenzene cations in the gaseous phase and their lifetimes in the (0o) states
John Paul Maier, O. Marthaler, Manijeh Mohraz, R.H. Shiley
1980, Chemical Physics (47) 295-305
The radiative decay of seventeen electronically excited chlorofluorobenzene cations in the gaseous phase has been detected. The reported emission spectra, which have been obtained using low energy electron beam excitation, are assigned to the B(??-1 ??? X(??-1 electronic transitions of these cations on the basis of their Ne(I) photoelectron spectra....
Secular, annual, and semiannual changes in the baseline level of the earth's magnetic field at North American locations
W.H. Campbell
1980, Journal of Geophysical Research Solid Earth (85) 6557-6571
Secular, annual, and semiannual changes were obtained from the midnight values of field on specially determined days of quiet magnetospheric conditions. From a selection of North American observatories the latitude variation of these changes was evaluated from 20° to 65°. Results for the active and quiet sun years (1958 and...
The provenance of rutile.
E. R. Force
1980, Journal of Sedimentary Petrology (50) 485-488
Most coarse detrital rutile is derived from high-grade metamorphic rocks. Contrary to a conventional assumption, independent rutile grains are particularly rare in igneous rocks except alkalic rocks. The use of rutile in the ZTR (zircon-tourmaline-rutile) index of mineralogic maturity is only partially valid,...
The morphology of the Martian surface
M. H. Carr
1980, Space Science Reviews (25) 231-284
Most of the southern hemisphere of Mars is densely cratered and stands 1-3 km above the topographic datum. The northern hemisphere is more sparsely cratered and elevations are generally below the datum. A broad rise, the Tharsis bulge, centered at 14?? S, 101?? W, is 8000 km across and 10...
Elastic moduli of rock glasses under pressure to 8 kilobars and geophysical implications
R. Meister, E.C. Robertson, R.W. Werke, R. Raspet
1980, Journal of Geophysical Research Solid Earth (85) 6461-6470
Shear and longitudinal velocities were measured by the ultrasonic phase comparison method as a function of pressure to 8 kbar on synthetic glasses of basalt, andesite, rhyolite, and quartz composition and on natural obsidian. Velocities of most of the glasses decrease anomalously with pressure, but increasingly more-normal behavior occurs with...
Degradation of the Hebgen Lake fault scarps of 1959
R.W. Wallace
1980, Geology (8) 225-229
Scarps produced during the Hebgen Lake earthquake of 1959 changed noticeably in 19 yr although they still appeared remarkably fresh in 1978. They have degraded much more rapidly than have those produced in 1915 and 1954 in Nevada, but a quasi-stable slope of...
Petroleum geology of Kodiak Shelf, Alaska.
Michael A. Fisher
1980, American Association of Petroleum Geologists Bulletin (64) 1140-1157
Organic geochemical data show that Cenozoic rocks on Kodiak Island, in Albatross basin, and under the continental slope generally contain less than 0.5 wt. % organic carbon. Moreover, kerogen from all rocks analyzed is predominantly (60 to 100%) herbaceous; woody and coaly kerogens are present in secondary (20 to 40%)...
Goat paddock cryptoexplosion crater, Western Australia
J.E. Harms, D.J. Milton, J. Ferguson, D.J. Gilbert, W.K. Harris, B. Goleby
1980, Nature (286) 704-706
Goat Paddock, a crater slightly over 5 km in diameter (18??20??? S, 126??40???E), lies at the north edge of the King Leopold Range/Mueller Range junction in the Kimberley district, Western Australia (Fig. 1). It was noted as a geological anomaly in 1964 during regional mapping by the Bureau of Mineral...
