Petrology of the Precambrian intrusive center at Lake George, southern Front Range, Colorado
R. A. Wobus, R. S. Anderson
1978, Journal of Research of the U.S. Geological Survey (6) 81-94
The intrusive center at Lake George, at the western margin of the Pikes Peak batholith (1030 m.y.) of central Colorado, contains rocks of both the potassic and sodic differentiation trends recognized in the batholith. Finer grained variants of the Pikes Peak Granite initially formed a texturally zoned stock 8 kilometers...
Porphyry copper exploration model for northern Sonora, Mexico
Gary L. Raines
1978, Journal of Research of the U.S. Geological Survey (6) 51-58
The regional tectonic pattern of the porphyry copper province of northern Sonora, Mexico, is similar to, but more complex than, the Colorado mineral belt. Four northeast-trending shear zones, spaced at 30- to 50-kilometer intervals from Hermosillo, Mexico, north to Nogales, Mexico, are interpreted from analysis of lineament data from Landsat-1...
Hydrochemistry and hydrodynamics of injecting an iron-rich pickling liquor into a dolomitic sandstone: A laboratory study
Stephen E. Ragone, Francis S. Riley, Robert James Dingman
1978, Journal of Research of the U.S. Geological Survey (6) 1-9
Waste pickling liquor containing high concentrations of iron salts was injected into cores of quartzite, sandstone, and dolomite in a laboratory study to determine what effect this procedure might have on the permeability of these rock types. Experiments were performed at field conditions 40°C and 13.8 MPa (megapascals) in a...
A log-linear model approach to estimation of population size using the line-transect sampling method
David R. Anderson, K.P. Burnham, B.R. Crain
1978, Ecology (59) 190-193
The technique of estimating wildlife population size and density using the belt or line-transect sampling method has been used in many past projects, such as the estimation of density of waterfowl nestling sites in marshes, and is being used currently in such areas as the assessment of Pacific porpoise stocks...
Earthquake history of Wyoming
C. A. von Hake
1978, Earthquake Information Bulletin (USGS) (10) 150-154
Forty-five earthquakes of moderate intensity (V or greater) on the Modified Mercalli Intensity Scale (MM) and extent have originated in Wyoming from 1894 to 1976. Many shocks have occurred in Yellowstone National Park, including an intensity VII event in June 1975. the 1959 Hebgen Lake, Mont., earthquake, centered just west...
Geodimeter measurements and the Southern California uplift
W.H. Prescott, J.C. Savage
1978, Earthquake Information Bulletin (USGS) (10) 131-135
Modern surveying instruments, such as geodimeters, are capable of measuring distances in the range of 1 to 30 kilometers with remarkable precision. Indeed, the present limitation upon the precision of measurement is not the resolution of the instruments themselves but rather the uncertainty introduced by variations in the velocity of...
Earthquakes, November-December 1977
W. J. Person
1978, Earthquake Information Bulletin (USGS) (10) 97-99
Two major earthquakes occurred in the last 2 months of the year. A magnitude 7.0 earthquake struck San Juan Province, Argentina, on November 23, causing fatalities and damage. The second major earthquake was a magnitude 7.0 in the Bonin Islands region, an unpopulated area. On December 19, Iran experienced a...
Earthquake history of Wisconsin
C. A. von Hake
1978, Earthquake Information Bulletin (USGS) (10) 100-103
Only one earthquake of intensity V on the Modified Mercalli Intensity Scale (MM) or greater has occurred within Wisconsin during historic times. Some shocks originating in Illinois, Michigan, Missouri, Ohio, and Canada have been felt. ...
An automated procedure for the simultaneous determination of specific conductance and pH in natural water samples
D. E. Eradmann, Howard E. Taylor
1978, Analytica Chimica Acta (99) 269-274
An automated, continuous-flow system is utilized to determine specific conductance and pH simultaneously in natural waters. A direct electrometric procedure is used to determine values in the range pH 4–9. The specific conductance measurements are made with an electronically modified, commercially available conductivity meter interfaced to a separate module containing...
Silicate liquid immiscibility in magmas and in the system K2O-FeO-AI2O3-SiO2: An example of serendipity
E. Roedder
1978, Geochimica et Cosmochimica Acta (42) 1597-1617
The concept of silicate liquid immiscibility was invoked early in the history of petrology to explain certain pairs of compositionally divergent rocks, but. as a result of papers by Greig (Am. J. Sci.13, 1–44, 133–154) and Bowen (The Evolution of the Igneous Rocks), it fell into disfavor for many years....
Origin of major element chemical trends in DSDP Leg 37 basalts, Mid-Atlantic Ridge
G. R. Byerly, T. L. Wright
1978, Journal of Volcanology and Geothermal Research (3) 229-279
In this paper we summarize the major element chemical variation for basalts from the Deep Sea Drilling Project Leg 37 and relate it to stratigraphic position in each of five drilling sites. Least-squares techniques are successfully used to quantify the nature and extent of alteration in these basalts, and to...
Applications of the VLF induction method for studying some volcanic processes of Kilauea volcano, Hawaii
C.J. Zablocki
1978, Journal of Volcanology and Geothermal Research (3) 155-195
The very low-frequency (VLF) induction method has found exceptional utility in studying various volcanic processes of Kilauea volcano, Hawaii because: (1) significant anomalies result exclusively from ionically conductive magma or still-hot intrusions (> 800??C) and the attendant electrolytically conductive hot groundwater; (2) basalt flows forming the bulk of Kilauea have...
Cobalt and scandium partitioning versus iron content for crystalline phases in ultramafic nodules
W.E. Glassley, D.Z. Piper
1978, Earth and Planetary Science Letters (39) 173-178
Fractionation of Co and Sc between garnets, olivines, and clino- and orthopyroxenes, separated from a suite of Salt Lake Crater ultramafic nodules that equilibrated at the same T and P, is strongly dependent on Fe contents. This observation suggests that petrogenetic equilibrium models of...
P-Wave to Rayleigh-wave conversion coefficients for wedge corners; model experiments
A.F. Gangi, R. L. Wesson
1978, Journal of Computational Physics (29) 370-388
An analytic solution is not available for the diffraction of elastic waves by wedges; however, numerical solutions of finite-difference type are available for selected wedge angles. The P- to Rayleigh-wave conversion coefficients at wedge tips have been measured on two-dimensional seismic models for stress-free wedges with wedge angles, ??0, of...
Induction of auroral zone electric currents within the Alaska pipeline
W.H. Campbell
1978, Pure and Applied Geophysics PAGEOPH (116) 1143-1173
The Alaskar pipeline is a highly conducting anomaly extending 800 miles (1300 km) from about 62?? to 69?? geomagnetic latitude beneath the most active regions of the ionospheric electrojet current. The spectral behavior of the magnetic field from this current was analyzed using data from standard geomagnetic observatories to establish...
Empirical model of Skeletonema costatum photosynthetic rate, with applications in the San Francisco Bay estuary
James E. Cloern
1978, Advances in Water Resources (1) 267-274
An empirical model of Skeletonema costatum photosynthetic rate is developed and fit to measurements of photosynthesis selected from the literature. Because the model acknowledges existence of: 1) a light-temperature interaction (by allowing optimum irradiance to vary with temperature), 2) light inhibition, 3) temperature inhibition, and 4) a salinity effect, it accurately estimates...
Decomposition of hydroxy amino acids in foraminiferal tests; kinetics, mechanism and geochronological implications
J.L. Bada, M.-Y. Shou, E.H. Man, R. A. Schroeder
1978, Earth and Planetary Science Letters (41) 67-76
The diagenesis of the hydroxy amino acids serine and threonine in foraminiferal tests has been investigated. The decomposition pathways of these amino acids are complex; the principal reactions appear to be dehydration, aldol cleavage and decarboxylation. Stereochemical studies indicate that the...
Isotopic composition of lead in oceanic basalt and its implication to mantle evolution
M. Tatsumoto
1978, Earth and Planetary Science Letters (38) 63-87
New data are given in this report for (1) Pb isotopic compositions and U, Th, and Pb concentrations of basalts from the island of Hawaii; (2) redetermined Pb isotopic compositions of some abyssal tholeiites; and (3) U, Th, and Pb concentrations...
Heat flow in the Basin and Range province and thermal effects of tectonic extension
A.H. Lachenbruch
1978, Pure and Applied Geophysics PAGEOPH (117) 34-50
In regions of tectonic extension, vertical convective transport of heat in the lithosphere is inevitable. The resulting departure of lithosphere temperature and thickness from conduction-model estimates depends upon the mechanical mode of extension and upon how rapidly extension is (and has been) taking place. Present knowledge of these processes is...
The moon: Composition determined by nebular processes
J. W. Morgan, J. Hertogen, E. Anders
1978, The Moon and the Planets (18) 465-478
The bulk composition of the Moon was determined by the conditions in the solar nebula during its formation, and may be quantitatively estimated from the premise that the terrestrial planets were formed by cosmochemical processes similar to those recorded in the chondrites. The calculations are based on the Ganapathy-Anders 7-component...
Present day serpentinization in New Caledonia, Oman and Yugoslavia
I. Barnes, J. R. O’Neil, J.J. Trescases
1978, Geochimica et Cosmochimica Acta (42) 144-145
Geochemical evidence for modern low-temperature serpentinization has been found in three new localities. Apparently the low-temperature reactions are a common mode of formation of the lizardite-chrysotile and brucite assemblage. Possibly the 18O content of serpentine formed at low temperatures is in part inherited from the pyroxene and olivine. ?? 1978....
The use of a paired comparison model in ordering stratigraphic events
Lucy E. Edwards, R.J. Beaver
1978, Journal of the International Association for Mathematical Geology (10) 261-272
Data from lowest and highest occurrence events in several stratigraphic sections are analyzed by means of a paired comparison model with ties. The model produces an estimated relative geochronological ordering of these events. This ordering must be compared with actual observations for revision and interpretation. ...
Chemical composition and distribution of lithium-rich brines in salar de Uyuni and nearby salars in southwestern Bolivia
George E. Ericksen, James D. Vine, Raul Ballon A.
1978, Energy (3) 355-363
Preliminary investigations at Salar de Uyuni and the nearby salars (salt pans) of Coipasa and Empexa in the southern part of the Bolivian Altiplano show the presence of widespread lithium-rich brines. Widely scattered brine samples from Salar de Uyuni, which...
Possible fossil H2O liquid-ice interfaces in the Martian crust
L.A. Soderblom, D. B. Wenner
1978, Icarus (34) 622-637
Throughout the northern equatorial region of Mars, extensive areas have been uniformly stripped, roughly to a constant depth. These terrains vary widely in their relative ages. A model is described here to explain this phenomenon as reflecting the vertical distribution of H2O liquid and ice in the crust. Under present...
The crystal structure and thermal history of orthopyroxene from lunar anorthosite 15415
H. T. Evans Jr., Huebner J. Stephen, J.A. Konnert
1978, Earth and Planetary Science Letters (37) 476-484
A single crystal of untwinned orthopyroxene from lunar anorthosite sample 15415, with composition (Mg1.14Fe0.80Mn0.02Ca0.04)(Si1.97Al0.03)O6, has a unit cell in space groupPbca witha = 18.310(15)Å,b = 8.904(10)Å,c = 5.214(7)Å, containing 2 formula units. A set of 742 counter-measured intensity data made with MoKα radiation has been used to refine the crystal structure in isotropic thermal mode...
