Potential for geophysical experiments in large scale tests
James H. Dieterich
1981, Geophysical Research Letters (8) 653-656
Potential research applications for large-specimen geophysical experiments include measurements of scale dependence of physical parameters and examination of interactions with heterogeneities, especially flaws such as cracks. In addition, increased specimen size provides opportunities for improved recording resolution and greater control of experimental variables. Large-scale experiments using...
Martian channels and valleys: Their characteristics, distribution, and age
M. H. Carr, G.D. Clow
1981, Icarus (48) 91-117
All Martian channels and valleys visible at a resolution of 125 to 300 meters between 65°N and 65°S were mapped at a scale of 1:5,000,000 and the maps then digitized. Correlations of valley presence with other surface features show that almost...
The logic of multispectral classification and mapping of land
Charles J. Robinove
1981, Remote Sensing of Environment (11) 231-244
The use of multispectral reflectance data as surrogates for land attributes must be done within strict rules of logic and with a recognition of judgmental factors such as the use of a priori or a posteriori classification schemes. The naming and describing of spectral classes as surrogates of information classes...
Improved spectrophotometric cell for hydrothermal solutions
N.J. Susak, D.A. Crerar, T.C. Forseman, J.L. Haas Jr.
1981, Review of Scientific Instruments (52) 428-431
A simple, inexpensive spectrophotometric cell was designed for use with aqueous solutions for which temperature is a maximum of 325??C and pressure, 28 MPa. The cell has an internal volume of 5 ml and a path length of 1.31 cm. Each furnace assembly is 120 mm in diameter ?? 150...
Petrology and geochronology of metamorphosed volcanic rocks and a middle Cretaceous volcanic neck in the east-central Sierra Nevada, California
R. W. Kistler, S.E. Swanson
1981, Journal of Geophysical Research Solid Earth (86) 10489-10501
Metamorphosed Mesozoic volcanic rocks from the east-central Sierra Nevada range in composition from basalt to rhyolite and have ages, based on whole rock Rb-Sr and U-Pb zircon dating, of about 237–224, 185, 163, 134, and 100 m.y. The major plutons of the batholith in this area are of Triassic (215–200...
Ne matrix spectra of the sym-C6Br3F3+ radical cation
V.E. Bondybey, T.J. Sears, T.A. Miller, C. Vaughn, J.H. English, R.S. Shiley
1981, Chemical Physics (61) 9-16
The electronic absorption and laser excited, wavelength resolved fluorescence spectra of the title cation have been observed in solid Ne matrix and vibrationally analysed. The vibrational structure of the excited B2A2??? state shows close similarity to the parent compound. The X2E??? ground state structure is strongly perturbed and irregular owing...
Preliminary paleomagnetic poles and correlation of the Proterozoic Uinta Mountain Group, Utah and Colorado
S.L. Bressler
1981, Earth and Planetary Science Letters (55) 53-64
Stable paleomagnetic directions have been obtained from seven sites spanning much of the 7-km-thick middle Proterozoic Uinta Mountain Group. The characteristic magnetization is carried partly by detrital(?) and secondary specularite and partly by hematite pigment. Preliminary paleomagnetic poles for six of...
Geologic controls of uranium mineralization in the Tallahassee Creek uranium district, Fremont County, Colorado.
K. A. Dickinson
1981, Mountain Geologist (18) 88-95
Two important orebodies have been defined by drilling in the Tallahassee Creek uranium district, Fremont County, Colorado, namely the Hansen and the Picnic Tree. Host rocks are respectively the upper Eocene Echo park Alluvium, and the lower Oligocene Tallahassee Creek Conglomerate. Average ore grade is about 0.08% U3O8. The principal...
Back-extraction of trace elements from organometallic-halide extracts for determination by flameless atomic absorption spectrometry
J. Robert Clark, John G. Viets
1981, Analytical Chemistry (53) 65-70
The Methyl isobutyl ketone-Amine synerGistic Iodkte Complex (MAGIC) extraction system offers the advantage that a large number of trace elements can be rapidly determined with a single sample preparation procedure. However, many of the elements extracted by the MAGIC system form volatile organometallic halide salts when the organic extract is...
Magnetic signals from the core of the earth and secular variation
L.R. Alldredge
1981, Journal of Geophysical Research Solid Earth (86) 7957-7965
An oscillating, radial magnetic dipole source was assumed to exist in the core of the earth, 100 km beneath the core-mantle boundary. As an approximation, electromagnetic propagation was assumed in the core in lieu of hydromagnetic propagation, which could not be used because of unknown internal fields.Using Debye potentials, the...
A distribution-free alternative to least-squares regression and its application to Rb/Sr isochron calculations
R.G. Vugrinovich
1981, Journal of the International Association for Mathematical Geology (13) 443-454
A distribution-free estimator of the slope of a regression line is introduced. This estimator is designated Sm and is given by the median of the set of n(n - 1)/2 slope estimators, which may be calculated by inserting pairs of points (Xi, Yi)and (Xj, Yj)into the slope formula Si =...
A numerical inversion of the Laplace transform solution to radial dispersion in a porous medium
A.F. Moench, A. Ogata
1981, Water Resources Research (17) 250-252
A special form of the numerical inversion of the Laplace transform described by Stehfest (1970) is applied to the transformed solution of dispersion in a radial flow system in a porous medium. The inversion is extremely simple to use because the weighting coefficients depend only on the number of terms...
On the use of the nephelometer in estuarine waters
A. Eaton, V. Grant, O. Bricker, D. Wells
1981, Estuaries (4) 379-384
A study of the problems encountered in nephelometric determinations of suspended sediment loads in the Chesapeake Bay estuary has led to development of a technique which uses nephelometer readings as a guide for sampling at vertical profiles in an estuary. This permits optimum sampling for concentration profiles and allows one...
Late Cenozoic stages and molluscan zones of the U.S. Middle Atlantic Coastal Plain
B. W. Blackwelder
1981, Journal of Paleontology, Supplement, Part II (55)
Pliocene to Holocene deposits of the U.S.Atlantic Coastal Plain from Maryland to Georgia are divided into four stages and four substages using molluscan biostratigraphic data. These divisions are the Wiltonian and Burwellian Stages (early Pliocene), Gouldian and Windyan Substages of the Colerainian Stage (late Pliocene to early Pleistocene), and Myrtlean...
Estimation of surface temperature variations due to changes in sky and solar flux with elevation
S. Hummer-Miller
1981, Geophysical Research Letters (8) 595-598
Sky and solar radiance are of major importance in determining the ground temperature. Knowledge of their behavior is a fundamental part of surface temperature models. These two fluxes vary with elevation and this variation produces temperature changes. Therefore, when using thermal-property differences to discriminate geologic materials,...
Chemical composition, stratigraphy, and depositional environments of the Black River Group (Middle Ordovician), southwestern Ohio.
David A. Stith
1981, Geological Society of America Bulletin (92) 629-633
The chemical composition and stratigraphy of the Black River Group in southwestern Ohio were studied. Chemical analyses were done on two cores of the Black River from Adams and Brown Counties, Ohio. These studies show that substantial reserves of high-carbonate rock are present in the Black River at depths of...
Faulting in outer continental shelf of southern Bering Sea
James V. Gardner, Tracy L. Vallier
1981, American Association of Petroleum Geologists Bulletin (65) 1568-1573
Synthesis of more than 10 000 line-km of high-resolution seismic data indicates the distribution, types, and trends of faults present on the outer continental shelf of the southern Bering Sea. Faults are classified into three types as to whether they 1) offset the sea floor (surface fault), 2) show less...
Late Cenzoic rhyolites from the Kern Plateau, southern Sierra Nevada, California.
C. R. Bacon, W. A. Duffield
1981, American Journal of Science (281) 1-34
Four late Cenozoic rhyolite domes lie atop the Kern Plateau, 30 to 40km S-SE of Mount Whitney. K-Ar and 40Ar/39Ar dating shows that Monache, Templeton, and Little Templeton Mountains are all about 2.4Ma old; a small dome nearby is approx 0.2Ma old. The three older rhyolites have SiO2 = 73-74%...
Preconsolidation stress of aquifer systems in areas of induced land subsidence
Thomas L. Holzer
1981, Water Resources Research (17) 693-704
Aquifer systems in the Eloy-Picacho area, Arizona, the Houston-Galveston area, Texas, and the Tulare-Wasco area and Santa Clara Valley, California, appear to have been overconsolidated by an amount that ranged approximately from 1.6 to 6.2 bars (16 to 63 m of water) before man began to withdraw groundwater from them....
Oxygen isotope thermometry of basic lavas and mantle nodules
T.K. Kyser, J. R. O’Neil, I. S. E. Carmichael
1981, Contributions to Mineralogy and Petrology (77) 11-23
Measurements have been made of the oxygen isotope and chemical composition of glass and phenocrysts in lavas and coexisting minerals in mantle nodules. Temperatures of formation of these assemblages have been estimated from various chemical thermometers and range from 855?? to 1,300?? C. The permil fractionations between coexisting orthopyroxene and...
Coincident sediment slump/clathrate complexes on the U.S. Atlantic continental slope
G. Carpenter
1981, Geo-Marine Letters (1) 29-32
High-resolution seismic reflection data recorded on the continental slope off the east coast of the United States have revealed instances of sediment mass movement (slumps) which appear to occur above clathrate accumulations. The slumping is believed to be related to the liberation of free gas by clathrate decomposition and consequent...
Heavy metals and manganese oxides in the genesee watershed, New York state: Effects of geology and land use
P.R. Whitney
1981, Journal of Geochemical Exploration (14) 95-117
Manganese oxide coatings on gravels from 255 sites on tributary streams in the Genesee River Watershed were analyzed for Mn, Fe, Zn, Cd, Co, Ni, Pb, and Cu. The results were compared with data on bedrock geology, surficial geology and land use, using factor analysis and stepwise multiple regression. All...
Geodetic strain measurements in Washington
J.C. Savage, M. Lisowski, W.H. Prescott
1981, Journal of Geophysical Research Solid Earth (86) 4929-4940
Two new geodetic measurements of strain accumulation in the state of Washington for the interval 1972–1979 are reported. Near Seattle the average principal strain rates are 0.07 ± 0.03 μstrain/yr N 19°W and −0.13 ± 0.02 μstrain/yr N71°E, and near Richland (south central Washington) the average principal strain rates are...
The origin and isotopic composition of dissolved sulfide in groundwater from carbonate aquifers in Florida and Texas
R. O. Rye, W. Back, B.B. Hanshaw, C.T. Rightmire, F. J. Pearson Jr.
1981, Geochimica et Cosmochimica Acta (45) 1941-1950
The δ34S values of dissolved sulfide and the sulfur isotope fractionations between dissolved sulfide and sulfate species in Floridan ground water generally correlate with dissolved sulfate concentrations which are related to flow patterns and residence time within the aquifer. The dissolved sulfide derives from the slow in situ biogenic reduction of sulfate dissolved from...
Origin and structural implications of upper Miocene rhyolites in Kingston Canyon, Piute County, Utah
P. D. Rowley, T. A. Steven, H. H. Mehnert
1981, Geological Society of America Bulletin (92) 590-602
Kingston Canyon is one of the deepest antecedent canyons in the High Plateaus subprovince of the Colorado Plateaus. Here the East Fork of the Sevier River flows westward transversely across the gently east tilted Sevier Plateau, which is developed on a basin-range fault...
