Depositional environments of some Pleistocene coastal terrace deposits, southwestern Oregon - case history of progradational beach and dune sequence.
R. E. Hunter
1980, Sedimentary Geology (27) 241-262
These deposits comprise a basal gravelly unit and 3 overlying sandy units, each with mud beds, a paleosol, or the modern soil in its uppermost part. The gravelly unit is interpreted as a progradational deposit. The main parts of the sandy units are made up of 1) a crossbedded sand...
Organic content of Devonian shale in western Appalachian basin
James W. Schmoker
1980, American Association of Petroleum Geologists Bulletin (64) 2156-2165
In the organic-rich facies of the Devonian shale in the western part of the Appalachian basin, the distribution of organic matter provides an indirect measure of both gas in place and the capacity of the shale to supply gas to permeable pathways.The boundary between organic-rich ('black') and organic-poor ('gray') facies...
Applications of statistics to thematic mapping.
G.H. Rosenfield, M.L. Melley
1980, Photogrammetric Engineering and Remote Sensing (46) 1287-1294
Two statistical problems occurring in the effort to analyze thematic maps and mapping are determining the accuracy of thematic content and comparing factors studied in thematic mapping. Statistical procedures applicable to thematic mapping involve sampling, determining accuracy, and comparing factors. A sampling procedure using an unaligned pattern within a square...
Geochemical evolution of brines in the Salar of Uyuni, Bolivia.
S.L. Rettig, B.F. Jones, F. Risacher
1980, Chemical Geology (30) 57-79
Recent analyses of brines from the Salars of Uyuni and Coipasa have been compared with published data for Lakes Titicaca and Poopo to evaluate solute compositional trends in these remnants of two large Pleistocene lakes once connected by overflow from the N to the S of the Bolivian Altiplano. From...
Computational methods for a three-dimensional model of the petroleum-discovery process
J.H. Schuenemeyer, W.J. Bawiec, L.J. Drew
1980, Computers & Geosciences (6) 323-360
A discovery-process model devised by Drew, Schuenemeyer, and Root can be used to predict the amount of petroleum to be discovered in a basin from some future level of exploratory effort: the predictions are based on historical drilling and discovery data. Because marginal costs of discovery and production are a...
The 1977 eruption of Kilauea volcano, Hawaii
R. B. Moore, Rosalind Tuthill Helz, D. Dzurisin, G. P. Eaton, R. Y. Koyanagi, P. W. Lipman, J. P. Lockwood, G. S. Puniwai
1980, Journal of Volcanology and Geothermal Research (7) 189-210
Kilauea volcano began to erupt on September 13, 1977, after a 21.5-month period of quiescence. Harmonic tremor in the upper and central east rift zone and rapid deflation of the summit area occurred for 22 hours before the outbreak of surface activity. On the first night, spatter ramparts formed along...
Computer-composite mapping for geologists
J.N. van Driel
1980, Environmental Geology (3) 151-157
A computer program for overlaying maps has been tested and evaluated as a means for producing geologic derivative maps. Four maps of the Sugar House Quadrangle, Utah, were combined, using the Multi-Scale Data Analysis and Mapping Program, in a single composite map that shows the relative stability of the land...
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....
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...
Declination and inclination errors in experimentally deposited specularite-bearing sand
S.L. Bressler, D. P. Elston
1980, Earth and Planetary Science Letters (48) 227-232
Naturally disaggregated specularite-bearing sandstone from the Triassic Moenkopi Formation, artificially deposited in controlled magnetic fields of ∼5 × 10−2 mT, acquires a stable remanent magnetization that has systematic errors in inclination and declination. Inclinations about 12° shallower than the applied fields are...
Asymmetric measures of association, closed data, and multivariate analysis
M. Hohn, E.B. Nuhfer
1980, Journal of the International Association for Mathematical Geology (12) 235-246
The association between constant-sum variables Xiand Xjexpressed as percentages can be calculated as a product-moment correlation between Xiand Xj/(100 - Xi) and a correlation between Xjand Xi/(100 - Xj). An asymmetric, square matrix may be formed from these coefficients, and multivariate analysis performed by two methods: singular value decomposition and...
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...
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...
U-Pb ages of uraniferous opals and implications for the history of beryllium, fluorine, and uranium mineralization at Spor Mountain, Utah
K.R. Ludwig, D. A. Lindsey, R. A. Zielinski, K. R. Simmons
1980, Earth and Planetary Science Letters (46) 221-232
The U-Pb isotope systematics of uraniferous opals from Spor Mountain, Utah, were investigated to determine the suitability of such material for geochronologic purposes, and to estimate the timing of uranium and associated beryllium and fluorine mineralization. The results indicate that uraniferous...
Speculations on processes responsible for mesoscale current lineations on the continental shelf, southern California
Herman A. Karl
1980, Marine Geology (34) M9-M18
A side-scan sonar survey of San Pedro shelf, California, reveals areas of mesoscale current lineations oriented approximately north-northeast in water depths of 20-25 m. Widths of sand ribbons range from 40 to 120 m and intervening erosional furrows, from 15 to 50 m. A conceptual model shows that the scale...
Hydrocarbon gas in sediment from the shelf, slope and basin of the Bering Sea.
K.A. Kvenvolden, G.D. Redden
1980, Geochimica et Cosmochimica Acta (44) 1145-1150
Methane, ethane, ethene, propane, propene, isobutane and n-butane are present in low concentrations in the top 2m of sediment. Methane is most abundant and its concentration increases with depth in the sediment. Ethane, ethene, propane and propene are present in almost all samples, but the concentrations of these gases are...
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,...
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,...
Littoral transport in the surf zone elucidated by an Eulerian sediment tracer
D.B. Duane, W.R. James
1980, Journal of Sedimentary Petrology (50) 929-942
An Eulerian, or time integration, sand tracer experiment was designed and carried out in the surf zone near Pt. Mugu, California on April 19, 1972. Data indicate that conditions of stationarity and finite boundaries required for proper application of Eulerian tracer theory exist...
Heat flow and energetics of the San Andreas fault zone
A.H. Lachenbruch, J.H. Sass
1980, Journal of Geophysical Research Solid Earth (85) 6185-6223
Approximately 100 heat flow measurements in the San Andreas fault zone indicate (1) there is no evidence for local factional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, (2) average heat flow is high (∼2 HFU, ∼80 mW m−2)...
Geothermal system at 21°N, East Pacific Rise: physical limits on geothermal fluid and role of adiabatic expansion
J. L. Bischoff
1980, Science (207) 1465-1469
Pressure-volume-temperature relations for water at the depth of the magma chamber at 21°N on the East Pacific Rise suggest that the maximum subsurface temperature of the geothermal fluid is about 420°C. Both the chemistry of the discharging fluid and thermal balance considerations indicate that the effective water/rock ratios in the...
Distribution of Quaternary rhyolite domes of the Coso Range, California: implications for extent of the geothermal anomaly.
C. R. Bacon, W. A. Duffield
1980, Journal of Geophysical Research (85) 2425-2433
38 separate domes and flows of phenocryst-poor, high-silica rhyolite of similar major element chemical composition were erupted over the past 1My from vents arranged in a crudely S-shaped array atop a granitic horst in the Coso Range, California. Most of the extrusions are probably less than about 0.3My old. The...
Calculation of uncertainties of U-Pb isotope data
K.R. Ludwig
1980, Earth and Planetary Science Letters (46) 212-220
Equations are derived for the estimation of errors and error correlations for various types of U-Pb isotope data, taking into account ion-beam instabilities, run-to-run variability in mass-discrimination, uncertainties in Pb and U concentrations, and uncertainties in initial-Pb and blank-Pb amount and isotopic composition. Equations are also given for the calculation...
Opaque minerals as aids in distinguishing between source and sorting effects on beach sand mineralogy in southwestern Oregon
G. Luepke
1980, Journal of Sedimentary Petrology (50) 489-496
Both source area and wave sorting affect the heavy-mineral distributions of beach sands. Although source and sorting effects are difficult to distinguish, they can be separated on four Oregon beaches by studying the magnetic fraction of the sand. Prominent headlands bound the four...
Sedimentary and structural patterns on the northern Santa Rosa-Cortes Ridge, southern California
Michael E. Field, William C. Richmond
1980, Marine Geology (34) 79-98
The Santa Rosa-Cortes Ridge is an 1800 m high, 180 km long feature lying approximately 90 km off the coast of southern California and directly south of the northern group of Channel Islands. Geophysical profiling and sampling cruises to the northern part of the ridge, an area of recent and...
