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Page 1560, results 38976 - 39000

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Small impact craters in the lunar regolith - Their morphologies, relative ages, and rates of formation
H. J. Moore, J. M. Boyce, D.A. Hahn
1980, The Moon and the Planets (23) 231-252
Apparently, there are two types of size-frequency distributions of small lunar craters (???1-100 m across): (1) crater production distributions for which the cumulative frequency of craters is an inverse function of diameter to power near 2.8, and (2) steady-state distributions for which the cumulative frequency of craters is inversely proportional...
A three-dimensional model to predict future oil discoveries in spatially connected multiple plays
J.H. Schuenemeyer, L.J. Drew, W.J. Bawiec
1980, Journal of the International Association for Mathematical Geology (12) 459-472
A discovery-process model that had been devised previously to estimate the size distribution of oil and gas fields remaining to be discovered in a single producing horizon was adapted to a basin containing spatially connected multiple plays and producing horizons. This model used the concept of the area of influence...
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...
The age curves of sulfur and oxygen isotopes in marine sulfate and their mutual interpretation
George E. Claypool, William T. Holser, Isaac R. Kaplan, Hitoshi Sakai, Israel Zak
1980, Chemical Geology (28) 199-260
Three hundred new samples of marine evaporite sulfate, of world-wide distribution, were analyzed for δ34S, and 60 of these also for δ18O in the sulfate ion. Detailed δ34S age curves for Tertiary—Cretaceous, Permian—Pennsylvanian, Devonian, Cambrian and Proterozoic times document large variations in δ34S. A summary curve forδ18O also shows definite...
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...
A model to forecast short-term snowmelt runoff using synoptic observations of streamflow, temperature, and precipitation
Wendell V. Tangborn
1980, Water Resources Research (16) 778-786
Snowmelt runoff is forecast with a statistical model that utilizes daily values of stream discharge, gaged precipitation, and maximum and minimum observations of air temperature. Synoptic observations of these variables are made at existing low- and medium-altitude weather stations, thus eliminating the difficulties and expense of new, high-altitude installations. Four...
Morphology of Lonar Crater, India: Comparisons and implications
R.F. Fudali, D.J. Milton, K. Fredriksson, A. Dube
1980, The Moon and the Planets (23) 493-515
Lonar Crater is a young meteorite impact crater emplaced in Deccan basalt. Data from 5 drillholes, a gravity network, and field mapping are used to reconstruct its original dimensions, delineate the nature of the pre-impact target rocks, and interpret the emplacement mode of the ejecta. Our estimates of the pre-erosion...
Stable isotope and fluid inclusion studies of carbonate deposits from the Tolfa Mountains mining district (Latium, central Italy)
U. Masi, V. Ferrini, J. R. O’Neil, J. N. Batchelder
1980, Mineralium Deposita (15) 351-359
Carbon and oxygen isotope analyses were made of representative samples of calcite and quartz from the carbonate deposits in the Tolfa Mountains mining district. Measurements were also made of hydrogen isotope compositions, filling temperatures and salinities of fluid inclusions in these minerals. There are three stages of mineralization at Tolfa....
Geophysical observations of Kilauea Volcano, Hawaii, 2. Constraints on the magma supply during November 1975-September 1977
D. Dzurisin, L. A. Anderson, G. P. Eaton, R. Y. Koyanagi, P. W. Lipman, J. P. Lockwood, R.T. Okamura, G. S. Puniwai, M. K. Sako, K.M. Yamashita
1980, Journal of Volcanology and Geothermal Research (7) 241-269
Following a 22-month hiatus in eruptive activity, Kilauea volcano extruded roughly 35 ?? 106 m3 of tholeiitic basalt from vents along its middle east rift zone during 13 September-1 October, 1977. The lengthy prelude to this eruption began with a magnitude 7.2 earthquake on 29 November, 1975, and included rapid...
Radar, visual and thermal characteristics of Mars: Rough planar surfaces
G. G. Schaber
1980, Icarus (42) 159-184
High-resolution Viking Orbiter images (10 to 15 m/pixel) contain significant information on Martian surface roughness at 25- to 100-m lateral scales, whereas Earth-based radar observations of Mars are sensitive to roughness at lateral scales of 1 to 30 m, or more....
Nearshore current pattern off south Texas: an interpretation from aerial photographs.
R. E. Hunter, G. W. Hill
1980, Remote Sensing of Environment (10) 115-134
Current patterns in a 4-km-wide zone along the south Texas coast were interpreted from patterns of water turbidity visible in aerial photographs taken during a winter day of moderate northerly winds. Features of the turbidity pattern remained recognizable on photographs taken 25 min apart. Currents measured from the movements of...
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...
Tectonic state: its significance and characterization in the assessment of seismic effects associated with reservoir impounding
R. O. Castle, M. M. Clark, A. Grantz, J.C. Savage
1980, Engineering Geology (15) 53-99
Any analysis of seismicity associated with the filling of large reservoirs requires an evaluation of the natural tectonic state in order to determine whether impoundment is the basic source, a mechanically unrelated companion feature, or a triggering stimulus of the observed seismicity. Several arguments indicate that the associated seismicity is...
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...
A lead isotope study of mineralization in the Saudi Arabian Shield
J. S. Stacey, B. R. Doe, R. J. Roberts, M.H. Delevaux, J. W. Gramlich
1980, Contributions to Mineralogy and Petrology (74) 175-188
New lead isotope data are presented for some late Precambrian and early Paleozoic vein and massive sulfide deposits in the Arabian Shield. Using the Stacey Kramers (1975) model for lead isotope evolution, isochron model ages range between 720 m.y. and 420 m.y. Most of the massive sulfide deposits in the...
An econometric model of the U.S. secondary copper industry: Recycling versus disposal
M.E. Slade
1980, Journal of Environmental Economics and Management (7) 123-141
In this paper, a theoretical model of secondary recovery is developed that integrates microeconomic theories of production and cost with a dynamic model of scrap generation and accumulation. The model equations are estimated for the U.S. secondary copper industry and used to assess the impacts that various policies and future...
Nd-isotopes in selected mantle-derived rocks and minerals and their implications for mantle evolution
A. R. Basu, M. Tatsumoto
1980, Contributions to Mineralogy and Petrology (75) 43-54
The Sm-Nd systematics in a variety of mantle-derived samples including kimberlites, alnoite, carbonatite, pyroxene and amphibole inclusions in alkali basalts and xenolithic eclogites, granulites and a pyroxene megacryst in kimberlites are reported. The additional data on kimberlites strengthen our earlier conclusion that kimberlites are derived from a relatively undifferentiated chondritic...
Implications of regional gravity for state of stress in the earth's crust and upper mantle
M. McNutt
1980, Journal of Geophysical Research Solid Earth (85) 6377-6396
Topography is maintained by stress differences within the earth. Depending on the distribution of the stress we classify the support as either local or regional compensation. In general, the stresses implied in a regional compensation scheme are an order of magnitude larger than those corresponding to local isostasy. Gravity anomalies,...
Mixing models and ionic geothermometers applied to warm (up to 60°C) springs: Jordan Rift Valley, Israel
E. Mazor, D. Levitte, A.H. Truesdell, J. Healy, A. Nissenbaum
1980, Journal of Hydrology (45) 1-19
Mixing models and evaluation of SiO2 contents of warm-water manifestations in the Jordan—Dead Sea Rift Valley indicate that these waters are fed by aquifers with estimated temperatures of up to 68°C. These calculations and Na/K ratios, concentrations of Na, K and Ca, concentrations of atmospheric Ne, Ar, Kr and Xe;...
The comparison of usage and availability measurements for evaluating resource preference
Douglas H. Johnson
1980, Ecology (61) 65-71
Modern ecological research often involves the comparison of the usage of habitat types or food items to the availability of those resources to the animal. Widely used methods of determining preference from measurements of usage and availability depend critically on the array of components that the researcher, often with a...