A short-pulse electromagnetic transponder for hole-to-hole use
David L. Wright, Raymond D. Watts, Erik Bramsoe
1983, IEEE Transactions on Geoscience and Remote Sensing (GE-22) 720-725
We have made hole-to-hole observations through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. We found that the transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to...
VLF electromagnetic investigations of the crater and central dome of Mount St. Helens, Washington
J.N. Towle
1983, Journal of Volcanology and Geothermal Research (19) 113-120
A very low frequency (VLF) electromagnetic induction survey in the crater of Mount St. Helens has identified several electrically conductive structures that appear to be associated with thermal anomalies and ground water within the crater. The most interesting of these conductive structures lies beneath the central dome. It is probably...
The contribution of humic substances to the acidity of colored natural waters
B.G. Oliver, E.M. Thurman, Ronald L. Malcolm
1983, Geochimica et Cosmochimica Acta (47) 2031-2035
An operationally defined carboxyl content of humic substances extracted from rivers, streams, lakes, wetlands, and groundwaters throughout the United States and Canada is reported. Despite the diversity of the samples, only small variations were observed in this humic carboxyl content. The dissociation behavior of two combined fulvic/humic acid extracts was...
Nontronite from a low-temperature hydrothermal system on the Juan de Fuca Ridge
R. Murnane, D.A. Clague
1983, Earth and Planetary Science Letters (65) 343-352
A deposit of Fe-rich, Al-poor, hydrothermal nontronite was recovered from the Juan de Fuca Ridge. Analyses show the deposit to be mineralogically and chemically similar to nontronite described at other oceanic localities. The deposit is located near the tip of a...
Sequence of mineral assemblages in differentiated granitic pegmatites
J.J. Norton
1983, Economic Geology (78) 854-874
Revised sequence is (1) plagioclase, quartz, muscovite, (2) plagioclase, quartz, (3) quartz, perthite, plagioclase, (4) perthite, quartz, (5) quartz, plagioclase, perthite, spodumene (or petalite), amblygonite, (6) quartz, spodumene (or petalite), (7) quartz, microcline or perthite, (8) quartz, and (9) lepidolite or lithian mica, plagioclase, quartz, microcline....
Approximate sampling distribution of the serial correlation coefficient for small samples
Gary D. Tasker
1983, Water Resources Research (19) 579-582
The probability density function for the sample serial correlation coefficient r can be approximated byf(r) = (β(½, ½(T + 1)))−1(1 − r2)½(T− 1)(1+ c2 − 2cr)−½(T), whereβ is the Beta function, T= n− 2, c = ρ − [(1 + ρ)/(n − 3)], n is the number of observations, and ρ is the population lag one serial correlation. This distribution is derived from...
Calculation of amorphous silica solubilities at 25° to 300°C and apparent cation hydration numbers in aqueous salt solutions using the concept of effective density of water
Robert O. Fournier, Marshall L. Williams
1983, Geochimica et Cosmochimica Acta (47) 587-596
The solubility of amorphous silica in aqueous salt solutions at 25° to 300°C can be calculated using information on its solubility in pure water and a model in which the activity of water in the salt solution is defined to equal the effective density. pe, of “free” water in that solution....
T-XCO2 stability relations and phase equilibria of a calcic carbonate scapolite
B.G. Aitken
1983, Geochimica et Cosmochimica Acta (47) 351-362
At a total pressure of 5 kb, calcic, Cl-free scapolite (Me83) is stable relative to plagioclase-bearing assemblages at T ≧ 625°C">T ≧ 625°C, XCO2≧ 0.12">XCO2≧ 0.12. With decreasing temperature, scapolite breaks down to plagioclase + calcite. Scapolite is replaced by...
High paleointensities of the geomagnetic field from thermomagnetic studies on rift valley pillow basalts from the Mid- Atlantic Ridge
M. Prevot, E. A. Mankinen, S. Gromme, A. Lecaille
1983, Journal of Geophysical Research Solid Earth (88) 2316-2326
Nineteen pillow basalts dredged within the rift valley of the Mid-Atlantic Ridge at36.8°N were studied by the Thellier stepwise heating method in order to determine the paleointensity of the geomagnetic field when they erupted on to the sea floor. Previously reported fission track ages are...
Snow and ice in a changing hydrological world
M. F. Meier
1983, Hydrological Sciences Journal (28) 3-22
On the occasion of the 60th anniversary of the International Association of Hydrological Sciences, the 100th and 50th anniversaries of the First and Second International Polar Years, and the 25th anniversary of the International Geophysical Year, it seems appropriate to re-examine the world's water balance and the role of snow...
GEOLOGIC FRAMEWORK FOR GEOTHERMAL ENERGY IN THE CASCADE RANGE.
W. A. Duffield
1983, Conference Paper, Transactions - Geothermal Resources Council
Quaternary volcanoes of the Cascade Range form a 1200-km-long belt from northern California to southwest British Columbia and lie above the subduction zone formed as the Juan de Fuca plate is consumed beneath North America. Volcanoes throughout this belt may have been active during Quaternary time, and many have erupted...
A reconnaissance geochemical study of La Primavera geothermal area, Jalisco, Mexico
G.A. Mahood, A.H. Truesdell, M.L.A. Templos
1983, Journal of Volcanology and Geothermal Research (16) 247-261
The Sierra La Primavera, a late Pleistocene rhyolitic caldera complex in Jalisco, Me??xico, contains fumaroles and large-discharge 65??C hot springs that are associated with faults related to caldera collapse and to later magma insurgence. The nearly-neutral, sodium bicarbonate, hot springs occur at low elevations at the margins of the complex,...
Crustal structure of the northern mississippi embayment and a comparison with other continental rift zones
Walter D. Mooney, M.C. Andrews, A. Ginzburg, D.A. Peters, R. M. Hamilton
1983, Tectonophysics (94) 327-348
Previous geological and geophysical investigations have suggested that the Mississippi Embayment is the site of a Late Precambrian continental rift that was reactivated in the Mesozoic. New information on the deep structure of the northern Mississippi Embayment, gained through an extensive seismic refraction survey, supports a rifting hypothesis. The data...
The saltwater-freshwater interface in the Tertiary limestone aquifer, southeast Atlantic outer-continental shelf of the U.S.A.
R.H. Johnston
1983, Journal of Hydrology (61) 239-249
Hydrologic testing in an offshore oil well abandoned by Tenneco, Inc., determined the position of the saltwater-freshwater interface in Tertiary limestones underlying the Florida-Georgia continental shelf of the U.S.A. Previous drilling (JOIDES and U.S.G.S. AMCOR projects) established the existence of freshwater far offshore in this area. At the Tenneco well...
A teleseismic analysis of the New Brunswick earthquake of January 9, 1982
G. L. Choy, J. Boatwright, J. W. Dewey, S.A. Sipkin
1983, Journal of Geophysical Research Solid Earth (88) 2199-2212
The analysis of the New Brunswick earthquake of January 9, 1982, has important implications for the evaluation of seismic hazards in eastern North America. Although moderate in size (mb 5.7), it was well-recorded teleseismically. Source characteristics of this earthquake have been determined from analysis of data that were digitally recorded by...
Characteristic analysis-1981: Final program and a possible discovery
R.B. McCammon, J.M. Botbol, R. Sinding-Larsen, R. W. Bowen
1983, Journal of the International Association for Mathematical Geology (15) 59-83
The latest ornewest version of thecharacteristicanalysis (NCHARAN)computer program offers the exploration geologist a wide variety of options for integrating regionalized multivariate data. The options include the selection of regional cells for characterizing deposit models, the selection of variables that constitute the models, and the choice of logical combinations of variables...
Large partition coefficients for trace elements in high-silica rhyolites
G. Mahood, W. Hildreth
1983, Geochimica et Cosmochimica Acta (47) 11-30
The partitioning of 25 trace elements between high-silica rhyolitic glass and unzoned phenocrysts of potassic and sodic sanidine, biotite, augite, ferrohedenbergite, hypersthene, fayalite, titanomagnetite, ilmenite, zircon, and allanite has been determined by INAA on suites of samples from the mildly peralkaline...
Investigation of internal friction in fused quartz, steel, Plexiglass, and Westerly granite from 0.01 to 1.00 Hertz at 10-8 to 10-7 strain amplitude
Hsi-Ping Liu, L. Peselnick
1983, Journal of Geophysical Research Solid Earth (88) 2367-2379
A detailed evaluation on the method of internal friction measurement by the stress-strain hysteresis loop method from 0.01 to 1 Hz at 10−8 to 10−7 strain amplitude and 23.9°C is presented. Significant systematic errors in relative phase measurement can result from convex end surfaces of the sample and stress sensor and from...
Generalized adjustment by least squares ( GALS).
A.A. Elassal
1983, Photogrammetric Engineering and Remote Sensing (49) 201-206
The least-squares principle is universally accepted as the basis for adjustment procedures in the allied fields of geodesy, photogrammetry and surveying. A prototype software package for Generalized Adjustment by Least Squares (GALS) is described. The package is designed to perform all least-squares-related functions in a typical adjustment program. GALS is...
Structure, burial history, and petroleum potential of frontal thrust belt and adjacent foreland, southwest Montana
W. J. Perry Jr., B. R. Wardlaw, N. H. Bostick, E. K. Maughan
1983, American Association of Petroleum Geologists Bulletin (67) 725-743
The frontal thrust belt in the Lima area of southwestern Montana consists of blind (nonsurfacing) thrusts of the Lima thrust system beneath the Lima anticline and the Tendoy thrust sheet to the west. The Tendoy sheet involves Mississippian through Cretaceous rocks of the southwest-plunging nose of the Mesozoic Blacktail-Snowcrest uplift...
Chryse Basin channels: low-gradients and ponded flows.
Baerbel K. Lucchitta, H.M. Ferguson
1983, Journal of Geophysical Research (88) A553-A568
Gradients on the floors of the Martian outflow channels that are derived from radar-elevation profiles across Lunae Planum and Chryse Basin have much lower values than those obtained from the U.S. Geological Survey's topographic map. Whereas the gradients of Maja and Ares Valles are similar to those of the catastrophic...
Recent geologic development of Lake Michigan (U.S.A.)
D.L. Gross, R.A. Cahill
1983, Hydrobiologia (103) 193-198
The stresses placed on Lake Michigan since the advent of industrialization require knowledge of the sedimentology of the whole lake in order to make informed decisions for environmental planning. Sediment accumulation rates are low: areas of the lake receiving the most sediment average only 1 mm a-1; deep-water basins average...
Deep-sea Drilling Project Leg 89: The Mesozoic superocean
R. Moberly, S.O. Schlanger, M. Baltuck, J.A. Bergen, W. Dean, P.A. Floyd, N. Fujii, J.A. Haggerty, James G. Ogg, I. Premoli-Silva, A. Schaaf, R.G. Schaefer, W.V. Sliter, J.M. Whitman
1983, Nature (302) 381
[No abstract available]...
U. S. GEOLOGICAL SURVEY LAND REMOTE SENSING ACTIVITIES.
Doyle G. Frederick
1983, Conference Paper
USGS uses all types of remotely sensed data, in combination with other sources of data, to support geologic analyses, hydrologic assessments, land cover mapping, image mapping, and applications research. Survey scientists use all types of remotely sensed data with ground verifications and digital topographic and cartographic data. A considerable amount...
Hafnium isotope results from mid-ocean ridges and Kerguelen
Patchett P. Jonathan
1983, LITHOS (16) 47-51
176Hf/177Hf ratios are presented for oceanic volcanics representing both extremes of the range of mantle HfNdSr isotopic variation. Hf from critical mid-ocean ridgebasalts shows that 176Hf/177Hf does indeed have a greater variability than 143Nd/144Nd and 87Sr/86Sr in the depleted mantle. This extra variation is essentially of a random nature, and...
