Seismic hazard study of the western portion of the Garlock fault [California]
J.C. Stepp, John LaViolette, Gary Christenson
1980, Open-File Report 80-1172
Investigations of the western segment of the Garlock fault were conducted at Castac Lake, Twin Lakes and Oak Creek Canyon. Studies were concentrated on the youngest fault trace as delineated by Clark (1973). Seismic refraction surveys, topographic surveys and geologic mapping provided positive evidence for fault offsets in Quaternary deposits...
Resource estimation from historical data: Mercury, a test case
S.M. Cargill, D. H. Root, E. H. Bailey
1980, Journal of the International Association for Mathematical Geology (12) 489-522
A simple technique based on historical records of tonnage and grade of ore produced provides a means for calculating how much of a mineral product will be available in the future at various average grades. Estimates made on this basis are independent of geologic considerations or changing economic and political...
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...
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)...
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...
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...
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...
Mid- Tertiary climate of southeastern United States, the sporomorph evidence
N. O. Frederiksen
1980, Journal of Paleontology (54) 728-739
Climatic affinities of modern genera represented by late Eocene sporomorphs suggest that the climate of that time in southeastern United States was winter-dry tropical close to the Gulf of Mexico and marginal humid subtropical on the upper Coastal Plain. Lack of change of the sporomorph assemblages suggests that the climate...
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...
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...
Radiometric dating of sediments using fission tracks in conodonts
H.M. Sachs, M. Denkinger, C.L. Bennett, A. G. Harris
1980, Nature (288) 359-361
Conodonts are microfossils which are commonly found in marine rocks of Cambrian to Triassic age. Although their biological affinities are difficult to assess, conodonts are valuable stratigraphical indices for much of their geological range1. Recent work has also established that conodont colour alteration indices (CAI) are useful guides to diagenetic...
Mapping the Galilean satellites of Jupiter with Voyager data.
R. M. Batson
1980, Photogrammetric Engineering and Remote Sensing (46) 1303-1312
The four Galilean satellites of Jupiter are being mapped using image data from the Voyager 1 and 2 spacecraft. The maps are published at several scales and in several versions. Preliminary maps at 1:25,000,000-required for mission planning and preliminary science reports-were compiled within three weeks of data acquisition and have...
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...
Experimental study of free-surface flow instability and bedforms in shallow flows.
I. Karcz, D. Kersey
1980, Sedimentary Geology (27) 263-300
To test erosion and development of bed sculpture in unstable, pulsating shallow flow, 3 series of experiments were performed in a 10-m flume with flows of Reynolds Number up to 103, Froude Number up to 3.0, and slope up to 2%. In the first, the bed was rigid, in the...
Visual classification of very fine-grained sediments: Evaluation through univariate and multivariate statistics
M. Hohn, E.B. Nuhfer, R.J. Vinopal, D.S. Klanderman
1980, Journal of the International Association for Mathematical Geology (12) 589-606
Classifying very fine-grained rocks through fabric elements provides information about depositional environments, but is subject to the biases of visual taxonomy. To evaluate the statistical significance of an empirical classification of very fine-grained rocks, samples from Devonian shales in four cored wells in West Virginia and Virginia were measured for...
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...
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....
Comparison of three techniques for the determination of uranium and thorium in rocks
R. J. Hart, D.L. Reid, J. S. Stuckless, H.J. Welke
1980, Chemical Geology (29) 345-350
U and Th concentrations have been determined in a series of selected whole-rock samples, using three different techniques: neutron activation analysis (INAA), X-ray fluorescence spectrometry (XRF) and isotope dilution mass spectrometry (ID). The INAA technique yields U and Th data that are comparable with those obtained by ID over the...
Discrim: a computer program using an interactive approach to dissect a mixture of normal or lognormal distributions
N.J. Bridges, R.B. McCammon
1980, Computers & Geosciences (6) 361-396
DISCRIM is an interactive computer graphics program that dissects mixtures of normal or lognormal distributions. The program was written in an effort to obtain a more satisfactory solution to the dissection problem than that offered by a graphical or numerical approach alone. It combines graphic and analytic techniques using a...
Transition of basaltic lava from pahoehoe to aa, Kilauea Volcano, Hawaii: Field observations and key factors
Donald W. Peterson, Robert I. Tilling
1980, Journal of Volcanology and Geothermal Research (7) 271-293
Nearly all Hawaiian basaltic lava erupts as pahoehoe, and some changes to aa during flowage and cooling; factors governing the transition involve certain critical relations between viscosity and rate of shear strain. If the lava slows, cools, and stops in direct response to concomitant increase in viscosity before these critical...
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...
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...
Effect of leaching on apparent digestion coefficients of feedstuffs for salmonids
R. R. Smith, M. C. Peterson, A. C. Allred
1980, Progressive Fish-Culturist (42) 195-199
Fecal excretions were collected from rainbow trout (Salmo gairdneri) in metabolism chambers. In this method of collection the daily excretion is suspended in about 1 L of water. Aliquots of the suspension were separated into solid and liquid fractions by settling, centrifuging, or filtering. Solid and liquid fractions and the...
Thickness change involved in the peat-to- coal transformation for a bituminous coal of Cretaceous age in central Utah
Thomas A. Ryer, A.W. Langer
1980, Journal of Sedimentary Petrology (50) 987-992
The ratio of the thicknesses of a layer of peat and the coal bed formed from that peat has been calculated for a bituminous coal bed in central Utah. The method used involves comparison of the thickness of peat eroded by a laterally...
