Preliminary results of a gravity survey of the Henrys Lake quadrangle, Idaho and Montana
Donald L. Peterson, Irving J. Witkind
1975, Journal of Research of the U.S. Geological Survey (3) 228
A gravity survey of the Henrys Lake quadrangle shows that a gravity low with about 10 milligals of closure coincides with the Henrys Lake basin. The low is interpreted to reflect a basin fill of 1,100 m or more of Cenozoic sediments and volcanic rock. The data indicate that on...
Experimental abrasion of detrital gold
Warren E. Yeend
1975, Journal of Research of the U.S. Geological Survey (3) 203-212
The physical breakdown and abrasion rates of gold were studied using a tumbler to simulate natural high-energy environments. The gold fragments were tumbled for periods ranging from 30 to 240 h with different combinations of sand, cobbles, and water at velocities of 0.5 and 2.0 mi/h (0.85 and 3.22 km/h)....
Relative efficiencies of square and triangular grids in the search for elliptically shaped resource target
Donald A. Singer
1975, Journal of Research of the U.S. Geological Survey (3) 163-167
The relative efficiencies of equivalent-density, square and equilateral triangular (hexagonal) grids used in the search for elliptical targets are determined for ellipses having relative semi-major axes ranging from 0.50 to 1.00 of the square grid spacing and having shapes (minor axes/major axes) ranging from 0.2 to 1.0. Using the probability...
Ice ages and the thermal equilibrium of the earth, II
D.P. Adam
1975, Quaternary Research (5) 161-171
The energy required to sustain midlatitude continental glaciations comes from solar radiation absorbed by the oceans. It is made available through changes in relative amounts of energy lost from the sea surface as net outgoing infrared radiation, sensible heat loss, and latent heat...
Elevation changes in the central Transverse Ranges near Ventura, California
Jane M. Buchanan-Banks, Robert O. Castle, Joseph I. Ziony
1975, Tectonophysics (29) 113-125
Profiles of elevation changes developed from repeated levelings in the east-trending Transverse Ranges near Ventura, California, reveal three general types of vertical movements: 1. (1) broadly defined regional tilting; 2. (2) sharply defined differential movements across recently active faults; and 3. (3) differential subsidence centering on producing oil fields. Down-to-the-southeast...
The Pikes Peak batholith, Colorado front range, and a model for the origin of the gabbro-anorthosite-syenite-potassic granite suite
F. Barker, D. R. Wones, W. N. Sharp, G. A. Desborough
1975, Precambrian Research (2) 99-160
This study of the Pikes Peak batholith includes the mineralogy and petrology of quartz syenite at West Creek and of fayalite-bearing and fayalite-free biotite granite near Mount Rosa; major element chemistry of the batholith; comparisons with similar postorogenic, intracratonic, sodic to potassic intrusives; and genesis of the batholith.The batholith is...
Thermal-infrared spectra and chemical analyses of twenty-six igneous rock samples
R.K. Vincent, L. C. Rowan, R.E. Gillespie, C. Knapp
1975, Remote Sensing of Environment (4) 199-209
Emittance spectra in the 7.5 μm to 14 μm wavelength region and chemical compositions of 26 igneous rocks are reported. Experimental measurements on the rocks were made under simulated daytime field conditions. Some surface silicate contaminants, such as clayey silt, significantly...
Garnet peridotite xenoliths in a Montana, U.S.A., kimberlite
Hearn B. Carter Jr., F.R. Boyd
1975, Physics and Chemistry of the Earth (9) 247-255
Within a swarm of late middle Eocene subsilicic-alkalic diatremes, one diatreme 270 by 370 m and an associated dike contain common xenoliths of granulite and rare xenoliths of spinel peridotite and garnet peridotite. Six garnet lherzolite xenoliths have been found and these...
Al-augite and Cr-diopside ultramafic xenoliths in basaltic rocks from western United States
H. G. Wilshire, J.W. Shervais
1975, Physics and Chemistry of the Earth (9) 257-272
Ultramafic xenoliths in basalts from the western United States are divided into Al-augite and Cr-diopside groups. The Al-augite group is characterized by Al, Ti-rich augites, comparatively Fe-rich olivine and orthopyroxene, and Al-rich spinel, the Cr-diopside group by Cr-rich clinopyroxene and spinel and...
Magnitude and frequency of floods in small drainage basins in North Dakota
Orlo A. Crosby
1975, Water-Resources Investigations Report 19-75
This report describes methods for estimating flood-peak discharges having 2- to 50-year recurrence intervals on North Dakota streams draining less than 100 square miles ( 259 square kilometres). For gaged sites, frequency estimates are provided directly. For ungaged sites, flood peaks are estimated from multiple-regression equations using drainage-area size and,...
A summary of selected chemical-quality conditions in 66 California streams 1950-72
George A. Irwin, Michael Lemons
1975, Report
Water from California streams has been analyzed for concentrations of selected chemical constituents since the early 1950's. This summary includes about 1,200 water years of data from 88 sampling sites on 66 streams. Results of this summary show that about 80 percent of the sites had a mean dissolved-solids concentration...
Descriptions and chemical analyses for selected wells in the Tehama-Colusa Canal Service Area, Sacramento Valley, California
Ronald P. Fogelman
1975, Report
The Tehama-Colusa Canal Service Area is in the northwestern part of the Sacramento Valley, in parts of Yolo, Colusa, Glenn, and Tehama Counties. The area includes 450 square miles (1,160 square kilometres). The boundaries are: West, the eastern slopes of the Coast Ranges; north, Elder Creek; northeast, the Sacramento River...
In-situ measurements of seismic velocities at twelve locations in the San Francisco Bay region
J. F. Gibbs, T. E. Fumal, R. D. Borcherdt
1975, Open-File Report 75-564
No abstract available....
Thermal-infrared images as a basis for structure mapping, front range and adjacent plains in Colorado
Terry W. Offield
1975, Geological Society of America Bulletin (86) 495-502
High-altitude thermal-infrared images, taken at various times of the day over the Front Range and adjacent plains in Colorado, display many linear and circular topographic features. These features are enhanced by thermal shading effects and commonly are better displayed than in photographs. Comparison with geologic maps of a control area...
Contour map of the bedrock surface, Bristol Quadrangle, Connecticut
E. H. Handman, D.B. Meade
1975, Miscellaneous Field Studies Map 665-A
Contour map of the bedrock surface, New Britain Quadrangle, Connecticut
E. H. Handman
1975, Miscellaneous Field Studies Map 523-C
Map showing depth to bedrock, Mount Carmel Quadrangle, Connecticut
E. H. Handman, M. H. Ginsberg
1975, Miscellaneous Field Studies Map 540-B
Contour map of the bedrock surface, Collinsville Quadrangle, Connecticut
E. H. Handman
1975, Miscellaneous Field Studies Map 654-A
Surface water availability, Pickens County, Alabama
Marvin E. Davis, Alfred L. Knight
1975, Open-File Report 75-450
Water availability and geology of Hale County, Alabama
Marvin E. Davis, Thomas H. Sanford Jr., Patrick O. Jefferson
1975, Open-File Report 75-452
Geologic units that underlie and crop out in Hale County include the Tuscaloosa Group, Eutaw Formation, and Selma Group of Late Cretaceous age, and terrace deposits and alluvium of Quaternary age. The Cretaceous units dip southwest about 35 feet per mile and strike northwest. They consist chiefly of deposits of...
Water availability and geology of Sumter County, Alabama
Marvin E. Davis, Thomas H. Sanford, Patrick O. Jefferson
1975, Open-File Report 75-459
Geologic units that crop out in Sumter County include the Selma Group of Late Cretaceous age; the Midway and Wilcox Groups of Tertiary Age; and terrace deposits and alluvium of Quaternary age. The Tuscaloosa Group, consisting of the Coker and Gordo Formations, and Eutaw Formation of Late Cretaceous age underlie...
Water resources information needs for the Northwest Florida Management District
Water Resources Division, U.S. Geological Survey
1975, Open-File Report 75-160
Sulfur, fluorspar, magnesite, and aluminous chromite in Pakistan
Raymond H. Nagell
1975, Open-File Report 75-496
Reports and analyses on elemental sulfur, fluorspar, magnesite, and aluminous chromite were reviewed for the purpose of identifying and categorizing the known deposits, and to indicate those which seem to merit further study on the basis of available information. General conclusions drawn from the study are: (1) Although aluminous chromite...
Reconnaissance of the geology and ore mineralization in part of the Chagai District, Pakistan
Raymond H. Nagell
1975, Open-File Report 75-550
The Chagai District of the Quetta Division is in the northwestern part of Pakistan. Igneous activity during the Himalayan orogeny included the extrusion of horizontally layered andesites of the Cretaceous Sinjrani Volcanic Group, emplacement of monzonitic stocks of the Cretaceous Chagai intrusions, and the extrusion of flows and tuffs of the...
A digital-computer model for estimating drawdowns in the sandstone aquifer in Dane County, Wisconsin
R.S. McLeod
1975, Open-File Report 74-59
A digital-computer program was developed to compute nonsteady and steady-state hydrologic changes caused by pumping from a confined aquifer. The program computes head changes in the confined aquifer and the rate and volume of water withdrawn from aquifer boundaries.The program was used to model the sandstone aquifer underlying Dane County,...
