Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

184569 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 5955, results 148851 - 148875

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
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...
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...
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...
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...
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...
Age and origin of the Darrough Felsite, southern Toiyabe Range, Nevada
R. C. Speed, E.H. McKee
1976, Journal of Research of the U.S. Geological Survey (4) 75-81
The name Darrough Felsite was originally assigned to a body of fine-grained quartzofeldspathic igneous rock probably greater than 3 km thick that is exposed continuously over 100 km2 in the southern Toiyabe Range of central Nevada. The Darrough was supposed to consist mostly of intrusive rocks of probable Permian age....
Behavior of trace elements during magmatic processes - A summary of theoretical models and their applications
Joseph G. Arth
1976, Journal of Research of the U.S. Geological Survey (4) 41-47
Progress in understanding the behavior of trace elements during the processes that produce igneous rocks has been made possible by the parallel development of theoretical models to describe that behavior and analytical techniques that permit precise measurement of trace-element concentrations in igneous rocks and minerals. The result of this progress...
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...
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)...
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...
Method and importance of obtaining humic and fulvic acids of high purity
Ronald L. Malcolm
1976, Journal of Research of the U.S. Geological Survey (4) 37-40
A detailed procedure incorporating centrifugation, pressure filtration, dialysis, resin exchange, and freeze drying is given for the extraction and purification of fulvic and humic acids from soils and sediments. By use of the procedure humic acids have been prepared which have less than 0.22 percent ash. The isolation of relatively...