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Page 5926, results 148126 - 148150

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Chemical pollutants in field-collected canvasback tissues, eggs, and food materials
Donald H. White, M. P. Dieter, Rey C. Stendell
1976, Book chapter, Transactions of the Canvasback Workshop : April 6-7, 1976, Ramada Inn, Jamestown, North Dakota
In 1972 studies began on the levels of environmental pollutants in canvasback tissues, eggs, and food items. The purpose of the studies were to determine if the levels of toxic chemicals found in canvasbacks were of the magnitude to cause problems affecting reproduction and survival. Overall, levels of...
Incidence of lead shot in canvasbacks
Matthew C. Perry
1976, Book chapter, Transactions of the Canvasback Workshop : April 6-7, 1976, Ramada Inn, Jamestown, North Dakota
During 1975 and 1976, 2,544 canvasbacks (Aythya valisineria) from North Dakota, Wisconsin, Illinois, and Maryland were flouroscoped to determine the incidence of body shot. A significant increase from west to east was detected in the incidence of shot for immatures from the four states. The incidence of shot...
Preliminary assessment of aerial photography techniques for canvasback population analysis
R. E. Munro, D.L. Trauger
1976, Book chapter, Transactions of the Canvasback Workshop : April 6-7, 1976, Ramada Inn, Jamestown, North Dakota
Recent intensive research on the canvasback has focused attention on the need for more precise estimates of population parameters. During the 1972-75 period, various types of aerial photographing equipment were evaluated to determine the problems and potentials for employing these techniques in appraisals of canvasback populations. The equipment...
Comments on recent canvasback habitat trends and threats on Chesapeake Bay
Matthew C. Perry
1976, Book chapter, Transactions of the Canvasback Workshop : April 6-7, 1976, Ramada Inn, Jamestown, North Dakota
During the last 22 years, the North American winter population of canvasbacks has fluctuated from 481,000 in 1955 to 179,000 in 1972. The Chesapeake Bay population has averaged 33 percent of the North American population and 64 percent of the Atlantic Flyway population. In Maryland, significant annual fluctuations...
Trace-metal variation in soils and sagebrush in the Powder River Basin, Wyoming and Montana
Jon J. Connor, John R. Keith, Barbara M. Anderson
1976, Journal of Research of the U.S. Geological Survey (4) 49-59
A reconnaissance study of 28 trace metals in samples of surface soil (0-2.5 cm deep), subsurface soil (15-20 cm deep), and big sagebrush (Artemisia tridentata) that were collected from the Powder River Basin in Wyoming and Montana indicates that little variation occurs in nature at scales greater than about 35...
Bootstrap window, Elko and Eureka Counties, Nevada
James G. Evans, Thomas E. Mullens
1976, Journal of Research of the U.S. Geological Survey (4) 119-125
The Bootstrap window in the Roberts Mountains thrust of north-central Nevada contains a 1,500-ft (460-m)- thick autochthonous section of carbonate assemblage rocks. These carbonate rocks include the upper part of the Roberts Mountains Formation and an unnamed limestone of Devonian age. They contain abundant material that must have been deposited...
Halogen contents of igneous minerals as indicators of magmatic evolution of rocks associated with the Ray porphyry copper deposit, Arizona
Norman G. Banks
1976, Journal of Research of the U.S. Geological Survey (4) 91-117
The contents of Cl, F, and H2O+ (calculated) in some hydrous igneous minerals in intrusive rocks of Laramide age (70-60 m.y.) near Ray, Ariz., appear to be related to the age and the chemistry of the whole-rock samples. Apatite and biotite in younger, more silicic rocks contain more F but...
The source of hydrothermal solutions at Puerto Maunabo and its bearing on the base-metal-potassium feldspar association in Puerto Rico
M. H. Pease Jr.
1976, Journal of Research of the U.S. Geological Survey (4) 61-65
A quartz oligoclase porphyry exposed near Puerto Maunabo may provide evidence to further our understanding of the base-metal-potassium feldspar association known to occur in many of the porphyry-type copper deposits of Puerto Rico. The porphyry appears to be a magmatic differentiate on the border of the San Lorenzo batholith that...
Effects of air injection at Prompton Lake, Wayne County, Pennsylvania
James L. Barker
1976, Journal of Research of the U.S. Geological Survey (4) 19-25
Air injected into the hypolimnion of Prompton Lake at a maximum rate of 210 cubic feet per minute (6 cubic metres per minute) during a 65-day period (July 27 to September 30, 1973) produced the following results: (1) With cooler air temperatures prevailing, the mean subsurface temperature increased by 4.0°...
Age and tectonic significance of volcanic rocks on St. Matthew Island, Bering Sea, Alaska
William W. Patton Jr., Marvin A. Lanphere, Thomas P. Miller, Richard A. Scott
1976, Journal of Research of the U.S. Geological Survey (4) 67-73
Reconnaissance investigations of the heretofore little known volcanic assemblage on St Matthew Island provide significant information on the tectonic history of the Bering Sea shelf. St. Matthew Island is made up of approximately 500 m of subaerial calc-alkaline volcanic rocks ranging in composition from high-alumina basalt to rhyolite. Four K-Ar...
Petrology of the Paloma Valley ring complex, southern California batholith
D. M. Morton, A.M. Bard
1976, Journal of Research of the U.S. Geological Survey (4) 83-89
The Paloma Valley ring complex is one of the numerous plutons that make up the Cretaceous southern California batholith. The complex is composite, consisting of (1) an older, single ring dike and two subsidiary short-arced inner dikes, and (2) a younger set of thin short-arced dikes largely inside the older...
Stratigraphic and hydrologic relationship of the Piney Point aquifer and the Alloway Clay Member of the Kirkwood Formation in New Jersey
Bronius Nemickas, Louis D. Carswell
1976, Journal of Research of the U.S. Geological Survey (4) 1-7
Coarse quartzose (clastic) sediments of middle and late Eocene age in the subsurface of southern New Jersey are identified in this report as the Piney Point aquifer. The sediments are as thick as 220 feet (67 metres) and form a freshwater aquifer which is laterally continuous with the Piney Point...
Land subsidence and aquifer-system compaction in the San Jacinto Valley, Riverside County, California - A progress report
Ben Elder Lofgren
1976, Journal of Research of the U.S. Geological Survey (4) 9-18
Widespread subsidence continues in the San Jacinto structural trough as water levels continue to decline. Subsidence is due principally to the compaction of water-bearing deposits as effective stresses are increased by artesian-head decline. Other possible contributory causes of subsidence are (1) local or regional tectonic adjustments and graben downfaulting, (2)...