Habitat evaluation
1979, Water Spectrum (11) 26-34
Ours has been a nation of rapid growth and development; our abundant water and other natural resources were quickly utilized to meet the needs of our expansion. Resources perceived to be “important” to the national interest were often exploited at the expense of others. Fish and wildlife, because of their...
The composite dynamic method as evidence for age-specific waterfowl mortality
Kenneth P. Burnham, David R. Anderson
1979, Journal of Wildlife Management (43) 356-366
For the past 25 years estimation of mortality rates for waterfowl has been based almost entirely on the composite dynamic life table. We examined the specific assumptions for this method and derived a valid goodness of fit test. We performed this test on 45 data sets representing a...
Use of prairie pothole habitat by breeding mallards
T.J. Dwyer, Gary L. Krapu, D.M. Janke
1979, Journal of Wildlife Management (43) 526-531
Detailed information on the use by mallards (Anas platyrhynchos) of prairie pothole habitat during the nesting season is necessary to interpret habitat needs of the species during the breeding period. Many data have been collected and published relating pair counts to habitat use and water conditions (e.g., Evans and Black...
Alcoholic fermentation in swamp and upland populations of Nyssa sylvatica: Temporal changes in adaptive strategy
Jon E. Keeley, E. H. Franz
1979, American Naturalist (113) 587-592
Both the upland and swamp varieties of Nyssa sylvatica respond initially to flooding with an acceleration of ethanol production. Under continued flooding the roots of the upland variety sylvatica have decreased rates of ethanol production, very likely a result of the progressively worsening necrosis of the root system. Few of...
Age determination of mallards
Gary L. Krapu, Douglas H. Johnson, C.W. Dane
1979, Journal of Wildlife Management (43) 384-393
A technique for distinguishing adult from yearling wild mallards (Anas platyrhynchos), from late winter through the nesting season, was developed by applying discriminant analysis procedures to selected wing feather characters of 126 yearlings and 76 adults (2-year-olds) hand-reared from wild eggs during 1974, 1975, and 1977. Average values for feather...
Variable porosity in siliceous skeletons: Determination and importance
D.C. Hurd, C. Wenkam, H.S. Pankratz, J. Fugate
1979, Science (203) 1340-1343
Gas adsorption data were used to obtain the specific surface area and specific pore volume for a variety of biogenically precipitated silica samples. The results suggest that this material is finely divided and porous. This interpretation was corroborated by the use of transmission electron microscopy at magnifications...
Regional evaluation of wildlife habitat quality using rapid assessment methodologies
D.A. Asherin, H.L. Short, J. E. Roelle
1979, Book, Transactions of the forty-fourth North American Wildlife and Natural Resources Conference
No abstract available....
Altitude-age relationships of the lunar maria
Baerbel K. Lucchitta, J. M. Boyce
1979, Conference Paper
Altitudes and relative ages of mare surface units were compared to test if a systematic correlation in height of lava eruption surfaces and age might reflect a corresponding increase in depth of the magma chamber with time; in addition the altitudes were studied to shed light on the time and...
The beginnings of seismology in North America
1979, Earthquake Information Bulletin (USGS) (11) 47-49
The study of earthquakes advanced somewhat more slowly in North America than it did in Europe and Japan. J.D. Whitney, professor of geology at Harvard University and former State Geologist of California, studied the Owens Valley, Calif., earthquake of 1872 and reported on it that same year....
Comparison of Miocene provincial foraminiferal stages to coccolith zones in the California Continental Borderland
James K. Crouch, David Bukry
1979, Geology (7) 211-215
Biostratigraphic ages determined by planktic coccoliths and benthic foraminifera for the same core samples from the California Continental Borderland suggest that a significant overlap exists among provincial Miocene stages of California and that some of the benthic foraminifera commonly used to recognize these stages are time-transgressive. For example, samples assigned...
Strain-softening instability model for the San Fernando earthquake
W.D. Stuart
1979, Science (203) 907-910
Changes in the ground elevation observed before and immediately after the 1971 San Fernando, California, earthquake are consistent with a theoretical model in which fault zone rocks are strain-softening after peak stress. The model implies that the slip rate of the fault increased to about 0.1 meter per year near...
Structure of the atmosphere of Venus up to 110 kilometers: Preliminary results from the four Pioneer Venus entry probes
A. Seiff, D.B. Kirk, S.C. Sommer, R.E. Young, R.C. Blanchard, D.W. Juergens, J.E. Lepetich, P.F. Intrieri, J.T. Findlay, J.S. Derr
1979, Science (203) 787-790
The four Pioneer Venus entry probes transmitted data of good quality on the structure of the atmosphere below the clouds. Contrast of the structure below an altitude of 50 kilometers at four widely separated locations was found to be no more than a few degrees Kelvin, with...
Pioneer Venus radar mapper experiment
G.H. Pettengill, P.G. Ford, W.E. Brown, W.M. Kaula, C.H. Keller, H. Masursky, G.E. McGill
1979, Science (203) 806-808
Altimetry and radar scattering data for Venus, obtained from 10 of the first 13 orbits of the Pioneer Venus orbiter, have disclosed what appears to be a rift valley having vertical relief of up to 7 kilometers, as well as a neighboring, gently rolling plain. Planetary oblateness appears unlikely to...
Biogenic and thermogenic gas in gas-charged sediment of Norton Sound, Alaska
Keith A. Kvenvolden, C.H. Nelson, D.R. Thor, Matthew C. Larsen, G.D. Redden, J. B. Rapp, D. J. Des Marais
1979, Conference Paper, Proceedings of Eleventh Annual Offshore Technology Conference
Chemical and isotopic compositions of sediment gas from Norton Sound have been determined for near-surface, gas-charged sediments at two sites identified in acoustic profiles and bottom observations. At one site air-driven vibracorer penetrated sediment saturated with methane. The isotopic value suggests that the methane originated from active biological processes operating...
Results of a reconnaissance microearthquake survey of Bucaramanga, Colombia
W.D. Pennington, Walter D. Mooney, Rene van Hissenhoven, H. Meyer, J.E. Ramirez, Robert P. Meyer
1979, Geophysical Research Letters (6) 65-68
Six University of Wisconsin portable, continuously‐recording seismographs were operated for 3½ days in late 1976 in the Eastern Cordillera of Colombia in a 200‐km‐diameter array around Bucaramanga, where there are also three permanent stations of the Instituto Geofísico de Los Andes Colombianos. Twenty‐seven microearthquakes were recorded. Most can be well...
Modern biogenic gas-generated craters (sea-floor “pockmarks”) on the Bering Shelf, Alaska
Nelson C. Hans, D.R. Thor, Mark W. Sandstrom, Keith A. Kvenvolden
1979, GSA Bulletin (90) 1144-1152
As many as 1,340 small craters per square kilometre cover the sea floor of Norton Sound in the northeastern Bering Sea. The craters are circular pits, 1 to 10 m in diameter and less than 1 m deep, observed on sonographs over 20,000 km2 of northern Norton Sound sea floor. Craters...
Reply to discussion by Michael A. Collins, "Fresh ground water stored in aquifers under the continental shelf: implications from a deep test, Nantucket Island, Massachusetts"
F. A. Kohout, D.F. Delaney
1979, Water Resources Bulletin (15) 252-254
We appreciate the comments made in the discussion by Michael A. Collins,...
Regional geohydrology of the San Juan hydrologic basin of New Mexico, Colorado, Arizona, and Utah
Maurice E. Cooley, William G. Weist
1979, Open-File Report 79-1498
The San Juan Basin in the southeastern part of the Colorado Plateau, southwest of the San Juan Mountains, broadly includes the Acoma and Gallup Sags in its southern part and the small Chama Basin in its northeastern part. Regionally, the water-yielding strata (aquifers) dip inward toward the center of San...
The appearance and distribution of the gas-hydrate reflector off the southeastern United States.
Charles K. Paull, William P. Dillon
1979, Open-File Report 80-88
No abstract available....
Djurleite (Cu1.94S) and low chalcocite (Cu2S): New crystal structure studies
H. T. Evans Jr.
1979, Science (203) 356-358
Additional x-ray structure studies on low chalcocite generally confirm the previously reported structure but show that either disorder is present or the true space group is not P21/c but Pc, four of the 96 copper atoms in the monoclinic unit cell taking on twofold (linear) coordination. The crystal structure of...
Frontier Formation and equivalent rocks in eastern Wyoming
E. Allen Merewether, W. A. Cobban, E.T. Cavanaugh
1979, Mountain Geologist (16) 67-95
No abstract available....
Late Jurassic Independence dike swarm in eastern California
J.-H. Chen, James G. Moore
1979, Geology (7) 129-133
The Independence dike swarm in eastern California, more than 250 km long, extends from the eastern Sierra Nevada and Inyo Mountains through the Argus Range, Alabama Hills, and Spangler Hills to the Garlock fault, where it is offset 64 km before continuing into the Mojave Desert. The dike swarm includes...
Regional deformation of the Sierra Nevada, California, on conjugate microfault sets
J. P. Lockwood, James G. Moore
1979, Journal of Geophysical Research B: Solid Earth (84) 6041-6049
Strike slip microfaults are pervasive throughout the granitic rocks of the eastern Sierra Nevada. Offsets typically range from less than a millimeter to several tens of centimeters but exceed 100 m in some places. The spacing between microfaults varies from a few tens of centimeters to a few tens of...
Emplacement temperatures of unsorted and unstratified deposits of volcanic rock debris as determined by paleomagnetic techniques
Richard P. Hoblitt, Karl S. Kellogg
1979, GSA Bulletin (90) 633-642
Unsorted and unstratified deposits of volcanic rock debris typically flank recently active stratovolcanoes. It is often difficult, using standard geologic procedures, to establish whether a particular deposit was emplaced by a pyroclastic flow, lahar, rock avalanche, or glacier. Determination of the emplacement temperatures of clasts contained in the deposit aids...
Genesis of ore deposits in the San Juan Volcanic Field, Southwestern Colorado-lead isotope evidence
B. R. Doe, T. A. Steven, M.H. Delevaux, J. S. Stacey, P. W. Lipman, F. S. Fisher
1979, Economic Geology (74) 1-26
In the San Juan volcanic area of southwestern Colorado, the isotopic composition of lead in ores and ore prospects of Cenozoic age ranges widely: 17.72 to 21.13 for 206Pb/ 204Pb; 15.50 to 15.81 for 207Pb/ 204Pb; and 37.21 to 38 for 208Pb/ 204Pb. Examination of the lead isotope data indicates that once deposition of lead minerals...
