A method and fortran program for the computerized reconstruction of three-dimensional objects from serial sections
J.C. Tipper
1977, Computers & Geosciences (3) 579-599
Three-dimensional objects can be reconstructed automatically from sets of serial sections by using a suitable algorithm. For two-phase systems it is sufficient to match phase boundary loops between adjacent sections. When all possible neighboring pairs of sections have been compared in this manner, the bounding surfaces of the object are...
Paleomagnetic poles and polarity zonation from Cambrian and Devonian strata of Arizona
D. P. Elston, S.L. Bressler
1977, Earth and Planetary Science Letters (36) 423-433
Basal Paleozoic Tapeats Sandstone (Early and Middle Cambrian) in northern and central Arizona exhibits mixed polarity and a low-latitude paleomagnetic pole. Carbonates of Middle and early Late Cambrian age, and directly superposed carbonate and carbonate-cemented strata of latest Middle(?) and early...
Tellurium, a guide to mineral deposits
J.R. Watterson, G. B. Gott, G. J. Neuerburg, H. W. Lakin, J. B. Cathrall
1977, Journal of Geochemical Exploration (8) 31-48
Te dispersion patterns are useful in exploring for different types of mineral deposits and in providing additional information about known ore deposits. The Te content of rocks is given for five mining districts in the western United States: Coeur d'Alene, Idaho; Robinson, near Ely, Nevada; Montezuma, Colorado; Crater Creek...
Square wave voltammetry at the dropping mercury electrode: Experimental
J.A. Turner, J. H. Christie, M. Vukovic, R. A. Osteryoung
1977, Analytical Chemistry (49) 1904-1908
Experimental verification of earlier theoretical work for square wave voltammetry at the dropping mercury electrode is given. Experiments using ferric oxalate and cadmium(II) in HCl confirm excellent agreement with theory. Experimental peak heights and peak widths are found to be within 2% of calculated results. An example of trace analysis...
Estimation of the probability of success in petroleum exploration
J.C. Davis
1977, Journal of the International Association for Mathematical Geology (9) 409-427
A probabilistic model for oil exploration can be developed by assessing the conditional relationship between perceived geologic variables and the subsequent discovery of petroleum. Such a model includes two probabilistic components, the first reflecting the association between a geologic condition (structural closure, for example) and the occurrence of oil, and...
Automated atomic absorption spectrometric determination of total arsenic in water and streambed materials
M. Fishman, Roberto Spencer
1977, Analytical Chemistry (49) 1599-1602
An automated method to determine both inorganic and organic forms of arsenic In water, water-suspended mixtures, and streambed materials Is described. Organic arsenic-containing compounds are decomposed by either ultraviolet radiation or by suHurlc acid-potassium persulfate digestion. The arsenic liberated, with Inorganic arsenic originally present, is reduced to arsine with sodium...
The U.S. geological survey rass-statpac system for management and statistical reduction of geochemical data
G. VanTrump Jr., A.T. Miesch
1977, Computers & Geosciences (3) 475-488
RASS is an acronym for Rock Analysis Storage System and STATPAC, for Statistical Package. The RASS and STATPAC computer programs are integrated into the RASS-STATPAC system for the management and statistical reduction of geochemical data. The system, in its present form, has been in use for more than 9 yr...
Chemical geothermometers and mixing models for geothermal systems
R.O. Fournier
1977, Geothermics (5) 41-50
Qualitative chemical geothermometers utilize anomalous concentrations of various "indicator" elements in groundwaters, streams, soils, and soil gases to outline favorable places to explore for geothermal energy. Some of the qualitative methods, such as the delineation of mercury and helium anomalies in soil gases, do not require the presence of hot...
CO2-filled vesicles in mid-ocean basalt
J.G. Moore, J. N. Batchelder, C. G. Cunningham
1977, Journal of Volcanology and Geothermal Research (2) 309-327
Volatile-filled vesicles are present in minor amounts in all samples of mid-ocean basalt yet collected (and presumably erupted) down to depths of 4.8 km. When such vesicles are pierced in liquid under standard conditions, the volume expansion of the gas is 0.2 ?? 0.05 times the eruption pressure in bars...
Ground-water favorability and surficial geology of the Windham-Freeport area, Maine
Glenn C. Prescott
1977, Hydrologic Atlas 564
No abstract available....
Map showing lead-zinc deposits of South America
1977, Miscellaneous Field Studies Map 868-C
No abstract available....
Map showing Mesozoic magnetic anomalies, western North Atlantic
Hans Schouten, Kim D. Klitgord
1977, Miscellaneous Field Studies Map 915
No abstract available....
Map showing holocene surface expression of the Brawley fault, Imperial County, California
R. V. Sharp
1977, Miscellaneous Field Studies Map 838
No abstract available....
Graphic analysis of resources by numerical evaluation techniques (Garnet)
A.C. Olson
1977, Computers & Geosciences (3) 539-545
An interactive computer program for graphical analysis has been developed by the U.S. Geological Survey. The program embodies five goals, (1) economical use of computer resources, (2) simplicity for user applications, (3) interactive on-line use, (4) minimal core requirements, and (5) portability. It is designed to aid (1) the rapid...
Hydrothermal transport of heavy metals by seawater: The role of seawater/basalt ratio
W. Seyfried, J. L. Bischoff
1977, Earth and Planetary Science Letters (34) 71-77
Seawater reacted with basaltic glass at 260°C and 500 bars under water-dominated conditions (50 : 1 water/rock ratio) efficiently leached and maintained heavy metals in solution. Cu, Zn, and Ba are transferred in significant proportions to the aqueous phase, while Fe...
Interpretation of discordant 40Ar/39Ar age-spectra of mesozoic tholeiites from Antarctica
R.J. Fleck, J. F. Sutter, D.H. Elliot
1977, Geochimica et Cosmochimica Acta (41) 15-32
Conventional K-Ar ages of tholeiitic basalts of the Ferrar Group in the central Transantarctic Mountains indicate significant loss of radiogenic 40Ar from this unit over much of its outcrop area. Argon loss varies inversely with amount of devitrified matrix in the basalts, which have not been thermally or tectonically disturbed since...
An exploratory drilling exhaustion sequence plot program
J.H. Schuenemeyer, L.J. Drew
1977, Computers & Geosciences (3) 617-631
The exhaustion sequence plot program computes the conditional area of influence for wells in a specified rectangular region with respect to a fixed-size deposit. The deposit is represented by an ellipse whose size is chosen by the user. The area of influence may be displayed on computer printer plots consisting...
Spectral characteristics of geomagnetic field variations at low and equatorial latitudes
W.H. Campbell
1977, Journal of Atmospheric and Terrestrial Physics (39) 1217-1227
Geomagnetic field spectra from eight standard observations at geomagnetic latitudes below 30?? were studied to determine the field characteristics unique to the equatorial region. Emphasis was placed upon those variations having periods between 5 min and 4 hr for a selection of magnetically quiet, average, and active days in 1965....
Hydrochemistry of the Lake Magadi basin, Kenya
B.F. Jones, H.P. Eugster, S.L. Rettig
1977, Geochimica et Cosmochimica Acta (41) 53-72
New and more complete compositional data are presented for a large number of water samples from the Lake Magadi area, Kenya. These water samples range from dilute inflow (<0.1 g/kg dissolved solids) to very concentrated brines (>300 g/kg dissolved solids). Five distinct hydrologic stages can be recognized in the evolution...
Terrestrial analogs of the Hellespontus dunes, Mars
C. S. Breed
1977, Icarus (30) 326-340
Geomorphic features in the Hellespontus region, Mars, were compared with dunes of the crescentic ridge type in numerous terrestrial sand seas quantitatively by dimensional analysis of dune lengths, widths, and wavelengths. Mean values for the Hellespontus dunes are close to mean values derived from measurements of all sampled terrestrial sand...
Fluorite solubility equilibria in selected geothermal waters
D. Kirk Nordstrom, E. A. Jenne
1977, Geochimica et Cosmochimica Acta (41) 175-188
Calculation of chemical equilibria in 351 hot springs and surface waters from selected geothermal areas in the western United States indicate that the solubility of the mineral fluorite, CaF2, provides an equilibrium control on dissolved fluoride activity. Waters that are undersaturated...
The Guatemala earthquake and Caribbean Plate tectonics
George Plafker
1977, Earthquake Information Bulletin (USGS) (9) 18-20
The main fault along which the destructive Guatemala earthquake occurred was the Motagua fault. Ground breakage was observed in a continuous, well-defined line for 230 km. At its closest point, the fault is 25 km north of Guatemala City. Surface displacement across the fault was dominantly horizontal and sinistral (see...
Binorm-a fortran subroutine to calculate the percentiles of a standardized binormal distribution
R.B. McCammon
1977, Computers & Geosciences (3) 335-339
BINORM is a FORTRAN subroutine for calculating the percentiles of a standardized binormal distribution. By using a linear transformation, the percentiles of a binormal distribution can be obtained. The percentiles of a binormal distribution are useful for plotting purposes, for establishing confidence intervals, and for sampling from a mixed population...
Heavy-mineral variability in bottom sediments of the lower Chesapeake Bay, Virginia
F. Firek, G. L. Shideler, P. Fleischer
1977, Marine Geology (23) 217-235
Heavy minerals in bottom-sediment samples of the lower Chesapeake Bay show distribution patterns and interrelationships that denote characteristic mineral suites associated with defined geographic provinces. The Baymouth province has a garnet-hornblende-pyroxene suite, which is largely attributed to the influx of littoral and shelf sediments; the Eastern Shore province has a...
Recent metalliferous sediment in the North Pacific manganese nodule area
J. L. Bischoff, R.J. Rosenbauer
1977, Earth and Planetary Science Letters (33) 379-388
Quaternary sediments cored in the northeast Pacific nodule area (DOMES site C, 14°N, 126°W) contain a significant amount of hydrothermal metalliferous mud. Water content, color, mineralogy, and chemical composition are analogous to metalliferous sediments of the subequatorial East Pacific Rise.Correction for contribution of pelagic clay indicates the metalliferous fraction to...
