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Page 4761, results 119001 - 119025

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Relationship of two lacustrine ostracode species to solute composition and salinity: Implications for paleohydrochemistry ( Limnocythere sappaensis/staplini)
R. M. Forester
1983, Geology (11) 435-438
Nonmarine ostracode species are indicative of the physical and chemical nature of lacustrine environments. Although salinity has traditionally been regarded as one of the more important parameters that affect the occurrence patterns of lacustrine ostracodes, examination of the solute composition and salinities of...
Quaternary geology of the Rhode Island inner shelf
S. W. Needell, C. J. O’Hara, H.J. Knebel
1983, Marine Geology (53) 41-53
Five sedimentary units and three erosional unconformities identified in high-resolution seismic-reflection profiles reveal the stratigraphic framework and Quaternary history of the inner continental shelf south of Narragansett Bay, Rhode Island. Late Tertiary to early Pleistocene rivers eroded the pre-Mesozoic bedrock and the Upper Cretaceous to lower Tertiary coastal plain and...
Scoresum - A technique for displaying and evaluating multi-element geochemical information, with examples of its use in regional mineral assessment programs
M.A. Chaffee
1983, Journal of Geochemical Exploration (19) 361-381
A technique called SCORESUM was developed to display a maximum of multi-element geochemical information on a minimum number of maps for mineral assessment purposes. The technique can be done manually for a small analytical data set or can be done with a computer for a large data set. SCORESUM...
Seismicity at Fuego, Pacaya, Izalco, and San Cristobal Volcanoes, Central America, 1973-1974
S.R. McNutt, D.H. Harlow
1983, Bulletin Volcanologique (46) 283-297
Seismic data collected at four volcanoes in Central America during 1973 and 1974 indicate three sources of seismicity: regional earthquakes with hypocentral distances greater than 80 km, earthquakes within 40 km of each volcano, and seismic activity originating at the volcanoes due to eruptive processes. Regional earthquakes generated by the...
Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion
John D. Bredehoeft, Richard A. Young
1983, Water Resources Research (19) 1111-1121
In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what...
Analysis of spurious oscillation modes for the shallow water and Navier-Stokes equations
Roy A. Walters, G. F. Carey
1983, Computers and Fluids (11) 51-68
The origin and nature of spurious oscillation modes that appear in mixed finite element methods are examined. In particular, the shallow water equations are considered and a modal analysis for the one-dimensional problem is developed. From the resulting dispersion relations we find that the spurious modes in elevation are associated...
Strangways Crater, Northern Territory, Australia: Siderophile element enrichment and lithophile element fractionation
J. W. Morgan, G.A. Wandless
1983, Journal of Geophysical Research Solid Earth (88) A819-A829
The Strangways Crater, Northern Territory, Australia (15°12′S, 133°35′E), has a central core, about 10 km in diameter, of shocked granitic gneiss and amphibolite, and some remnants of a melt rock sheet, surrounded by outer rings of quartzite and siltstone to a diameter of 20–25 km. Seven samples of melt rock...
40Ar/39Ar and U-Th-Pb dating of separated clasts from the Abee E4 chondrite
D.D. Bogard, D.M. Unruh, M. Tatsumoto
1983, Earth and Planetary Science Letters (62) 132-146
Determinations of40Ar/39Ar and U-Th-Pb are reported for three clasts from the Abee (E4) enstatite chondrite, which has been the object of extensive consortium investigations. The clasts give40Ar/39Ar plateau ages and/or maximum ages of 4.5 Gy, whereas two of the clasts give...
Orickite and coyoteite, two new sulfide minerals from Coyote Peak, Humboldt County, California.
Richard C. Erd, G.K. Czamanske
1983, American Mineralogist (68) 245-254
Minute quantities of orickite and coyoteite occur with rare alkali iron sulphides in a mafic alkalic diatreme near Orick, Humboldt County. Orickite, NaxKyCu0.95Fe1.06zH2O (x,y < 0.03, z < 0.5), is hexagonal, a 3.695, c 6.16 A, D 4.212 g/cm3, Z = 4. The strongest XRD reflections are 3.08(100), 3.20(90), 2.84(60),...
Iron disulfide minerals and the genesis of roll-type uranium deposits
R. L. Reynolds, M. B. Goldhaber
1983, Economic Geology (78) 105-120
FeS 2 minerals in host rocks for deposits that contain fossil vegetal (organic) matter differ in abundance, distribution, texture, and sulfur isotopic ratios from FeS 2 minerals in host rocks for deposits that do not contain fossil vegetal matter. In three South Texas deposits lacking such organic matter, preore FeS 2 is dominantly euhedral pyrite which...
Statistical averaging of marine magnetic anomalies and the aging of oceanic crust
R.J. Blakely
1983, Journal of Geophysical Research Solid Earth (88) 2289-2296
Visual comparison of Mesozoic and Cenozoic magnetic anomalies in the North Pacific suggests that older anomalies contain less short-wavelength information than younger anomalies in this area. To test this observation, magnetic profiles from the North Pacific are examined from crust of three ages: 0–2.1, 29.3–33.1, and 64.9–70.3 m.y, B.P. For...
Selective concentration of cesium in analcime during hydrothermal alteration, Yellowstone National Park, Wyoming
T. E. C. Keith, J. M. Thompson, R. E. Mays
1983, Geochimica et Cosmochimica Acta (47) 795-804
Chemical and mineralogical studies of fresh and hydrothermally altered rhyolitic material in Upper and Lower Geyser Basins, Yellowstone National Park, show that all the altered rocks are enriched in Cs and that Cs is selectively concentrated in analcime. The Cs content of unaltered rhyolite lava flows, including those from which...
Carbonatite tuffs in the Laetolil Beds of Tanzania and the Kaiserstuhl in Germany
R. L. Hay, J. R. O’Neil
1983, Contributions to Mineralogy and Petrology (82) 403-406
Carbonatite lava and tephra are now well known. The only modern eruptive carbonatites, from Oldoinyo Lengai, Tanzania, are of alkali carbonatite, whereas all of the pre-modern examples are of calcite or dolomite. Chemical and stable isotope analyses were made of separate phases of Pliocene carbonatite tuffs of the Laetolil Beds...
Tin granites of Seward Peninsula, Alaska
T. Hudson, Joseph G. Arth
1983, Geological Society of America Bulletin (94) 768-790
Seven granite plutons, spatially and genetically related to tin metalization, are exposed in a 170-km-long belt across northwestern Seward Peninsula, Alaska. These plutons are cupolas and epizonal composite stocks that consist of several textural varieties of biotite granite, including medium- to coarse-grained seriate...
Stability of streams and lakes on Mars
M. H. Carr
1983, Icarus (56) 476-495
Under present climatic conditions streams and lakes on Mars will freeze. Freezing is slow and would have a negligible effect in impeding flow of the large floods that are believed to have eroded the outflow channels. Valley networks are more difficult...
Seismological programs in Costa Rica
W. Montero
Henry Spall, editor(s)
1983, Earthquake Information Bulletin (USGS) (15) 11-15
At the beginning of the 1970's, a series of programs in seismology were initiated by different Costa Rican institutions, and some of these programs are still in the process of development. The institutions are Insituto Costaricense de Electricidad (ICE)- The Costa Rica Institute of Electricity La Universidad Nacional Autonoma (UNA)- The National...
Seismology in Chile
E. Kausel
1983, Earthquake Information Bulletin (USGS) (15) 16-22
The Department of Geology and Geophysics, which is under the faculties of Mathematics and Physical Sciences of the University of Chile, is the organization that is responsible for the Seismological Service of Chile and for installing,operating, and maintaining the seismological stations as well as all the strong-motion stations in Chile....
Glaciers: clues to future climate?
Richard S. Williams Jr.
1983, Report
A glacier is a large mass of ice having its genesis on land and represents a multiyear surplus of snowfall over snowmelt. At the present time, perennial ice covers about 10 percent of the land areas of the Earth. Although glaciers are generally thought of as polar entities, they also...
Distribution and abundance of larval fish in the nearshore waters of western Lake Huron
Robert O’Gorman
1983, Journal of Great Lakes Research (9) 14-22
Ichthyoplankton was collected at 17 nearshore (bottom depth ≥5 m but ≤10 m) sites in western Lake Huron during 1973–75 with a 0.5-m net of 351-micron mesh towed at 99 m/min. Larvae of rainbow smelt (Osmerus mordax) dominated late spring and early summer catches and larvae of alewives (Alosa pseudoharengus)...
Seasonal food of juvenile lake trout in U.S. waters of Lake Ontario
Joseph H. Elrod
1983, Journal of Great Lakes Research (9) 396-402
Stomach contents of 3,554 lake trout (Salvelinus namaycush), 100 to 449 mm in total length, captured with bottom trawls during April through October 1978–81 along the south shore of Lake Ontario were examined. Invertebrates appeared to be an important food of lake trout less than 200 mm long but were...
Publications of the Geological Survey, 1982
1983, Report
This catalog is a list of (1) books and maps that were published during 1982, and (2) articles by Geological Survey personnel in non-Geological Survey journals and books that came to our attention in 1982; it supplements the permanent catalogs "Publications of the Geological Survey, 1879-1961" and "Publications of the...
Notes on sedimentation activities calendar year 1982
1983, Report
This report is a digest of information furnished by those Federal agencies conducting sedimentation investigations. It includes descriptions of work in progress or planned, important findings, new methods, new publications, laboratory and other research activities, and other pertinent information. The material has been organized by major drainage regions in the...
A reexamination of the effects of adsorbates on the Raman spectrum of gibbsite
K.W. Cunningham, M. C. Goldberg
1983, Soil Science (136) 102-110
Previous workers have attributed substantial changes in the Raman intensities of the OH stretching bands in solid, powdered gibbsite of surface area 10 m2/g to surface interactions with the adsorbates 093Ca2+,HxPO43x- and SiO2.xH2O. These changes apparently resulted from an unsatisfactory Raman measurement procedure as a re-examination using an internal intensity...