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Page 1517, results 37901 - 37925

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Not all publications have extents, not all extents are completely accurate
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...
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...
CHEMICAL STRUCTURES IN COAL: GEOCHEMICAL EVIDENCE FOR THE PRESENCE OF MIXED STRUCTURAL COMPONENTS.
Patrick G. Hatcher, Irving A. Breger, G.E. Maciel, N.M. Szeverenyi
1983, Conference Paper
The purpose of this paper is to summarize work on the chemical structural components of coal, comparing them with their possible plant precursors in modern peat. Solid-state **1**3C nuclear magnetic resonance (NMR), infrared spectroscopy (IR), elemental analysis and, in some cases, individual compound analyses formed the bases for these comparisons....
VARIATIONS IN MINERAL MATTER CONTENT OF A PEAT DEPOSIT IN MAINE RESTING ON GLACIO-MARINE SEDIMENTS.
Cornelia C. Cameron, Paul Schruben
1983, Conference Paper, Los Alamos National Laboratory (Report) LA
The Great Heath, Washington County, Maine, is an excellent example of a multidomed ombrotrophic peatland resting on a gently undulating surface of glacio-marine sediments and towering above modern streams. A comprehensive study sponsored by the Geological Survey of Maine in cooperation with the U. S. Geological Survey included preparation of...
INTERACTIVE NAME PLACEMENT FOR PROVISIONAL MAPS.
Jeffrey L. Goldberg, Thomas C. Miller
1983, Conference Paper, Technical Papers of the American Congress of Surveying and Mapping
Computer generation and placement of map type has been refined into a production mode at Mid-Continent Mapping Center (MCMC) for USGS 1:24,000- and 1:25,000-scale Provisional maps. The map collar program is written in FORTRAN using batch processing that allows the program to work in the background....
Kinetic analysis of strontium and potassium sorption onto sands and gravels in a natural channel
Kenneth E. Bencala, Alan P. Jackman, Vance C. Kennedy, Ronald J. Avanzino, Gary W. Zellweger
1983, Water Resources Research (19) 725-731
A kinetic, first-order mass transfer model was used to describe the sorption of strontium onto sand- and gravel-sized streambed sediments. Rate parameters, empirically determined for strontium, allowed for the prediction of potassium sorption with moderate success. The model parameters varied significantly with particle size. The sorption data were collected during...
Mechanical and chemical compaction in fine-grained shallow-water limestones
E.A. Shinn, D.M. Robbin
1983, Journal of Sedimentary Petrology (53) 595-618
Artificial compaction of in-situ cores of sediments resulted in: 1) reduction of sediment thickness by 50 percent and more; 2) reduction of initial porosities of 65 to 75 percent to 35 to 45 percent; 3) creation of megascopic textures almost identical to many...
Major and trace elements in Mahogany zone oil shale in two cores from the Green River Formation, piceance basin, Colorado
M. L. Tuttle, W.E. Dean, N. L. Parduhn
1983, Conference Paper, Preprints Symposia
The Parachute Creek Member of the lacustrine Green River Formation contains thick sequences of rich oil-shale. The richest sequence and the richest oil-shale bed occurring in the member are called the Mahogany zone and the Mahogany bed, respectively, and were deposited in ancient Lake Uinta. The name "Mahogany" is derived...
The use of MAGSAT data to determine secular variation
J.C. Cain, J. Frayser, L. Muth, D. Schmitz
1983, Journal of Geophysical Research Solid Earth (88) 5903-5910
A combined spatial and secular variation model of the geomagnetic field, labeled M061581, is derived from a selection of Magsat data. Secular variation (SV) data computed from linear fits to midnight hourly values from 19 magnetic observatories were also included in the analysis but were seen to have little effect...
Characteristics of resuspended sediment from Georges Bank collected with a sediment trap
C.M. Parmenter, Michael H. Bothner, B. Butman
1983, Estuarine, Coastal and Shelf Science (17) 521-533
A sediment trap was deployed 3 m from the bottom at a water depth of 62 m on the southern flank of Georges Bank (41°02·2′N, 67°33·5′W) from 30 September 1978 to 10 March 1979 to qualitatively determine the size of sediments resuspended from the bottom by winter storms and to...
Reinterpretation of the exposed record of the last two cycles of Lake Bonneville, Western United States
W. E. Scott, W.D. McCoy, R. R. Shroba, M. Rubin
1983, Quaternary Research (20) 261-285
A substantially modified history of the last two cycles of Lake Bonneville is proposed. The Bonneville lake cycle began prior to 26,000 yr B.P.; the lake reached the Bonneville shoreline about 16,000 yr B.P. Poor dating control limits our knowledge of the timing of subsequent events. Lake level was maintained...
Taeniolite, an uncommon lithium-mica from Coyote Peak, Humboldt County, California.
Richard C. Erd, G.K. Czamanske, C.E. Meyer
1983, Mineralogical Record (14) 39-40
Taeniolite has been found in a late pegmatitic clot in a mafic alkalic diatreme at Coyote Peak; associated species are natrolite, pectolite, aegirine, barytolamprophyllite, rasvumite and sphalerite. The taeniolite is green-brown with sp. gr. (meas.) 2.85(1) and H. 31/2. Optically it is biaxial (-) with alpha 1.541(2), beta = gamma...
Isotopic and chemical composition of Parbati Valley geothermal discharges, north-west Himalaya, India
W.F. Giggenbach, R. Gonfiantini, B.L. Jangi, A.H. Truesdell
1983, Geothermics (12) 199-222
The isotopic compositions of the waters discharged from Parbati Valley geothermal areas indicate a higher altitude meteoric origin, with discharge temperatures reflecting variations in the depth of penetration of the waters to levels heated by the existence of a ‘normal’ geothermal gradient. On the basis of mixing models involving silica,...
Dual extraction of R-mode and Q-mode factor solutions
D. Zhou, T. Chang, J.C. Davis
1983, Journal of the International Association for Mathematical Geology (15) 581-606
It is mathematically possible to extract both R-mode and Q-mode factors simultaneously (RQ-mode factor analysis)by invoking the Eckhart-Young theorem. The resulting factors will be expressed in measures determined by the form of the scalings that have been applied to the original data matrix. Unless the measures for both solutions are...
Requirements for modeling trace metal partitioning in oxidized estuarine sediments
Samuel N. Luoma, J.A. Davis
1983, Marine Chemistry (12) 159-181
The fate of particulate-bound metals is of particular importance in estuaries because major biological energy flows involve consumption of detrital particles. The biological impact of particulate-bound metals is strongly influenced by the partitioning of metals among sediment components at the oxidized sediment-water interface. Adequate methods for directly measuring this partitioning...
Ground water for oil-shale development, Piceance Basin, Colorado
W.M. Alley
1983, Ground Water (21) 456-464
Vast deposits of oil shale are contained in the Piceance basin in northwestern Colorado. The basin may contain as much as 40 million acre-feet of stored water associated with these deposits, much of which may have to be drained for mining. Yet, most analyses of...
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...
Authigenic vivianite in Potomac River sediments: control by ferric oxy-hydroxides
P.P. Hearn, D.L. Parkhurst, E. Callender
1983, Journal of Sedimentary Petrology (53) 165-177
Sand-size particles of vivianite (Fe 3 (PO 4 ) 2 .8H 2 O) have been identified in surficial sediments of the tidal Potomac River near a major sewage treatment plant. Vivianite is concentrated in a surface layer of coarse-sand dredge spoil, which overlies much finer sediment. Although saturation indices indicate that...
Crustal and upper mantle structure of the northern and central Sierra Nevada
B.B. Mavko, G. A. Thompson
1983, Journal of Geophysical Research Solid Earth (88) 5874-5892
Teleseismic data were recorded within the Sierra Nevada to look for lateral variations in the upper mantle. The data were collected at both temporary and permanent stations, and P wave residuals were computed. After correcting the P residual data for crustal and topographic effects, there is still a variation of as much as 0.5-0.6...
The relationship of acquisition systems to automated stereo correlation.
A. P. Colvocoresses
1983, Photogrammetric Engineering and Remote Sensing (49) 539-544
Today a concerted effort is being made to expedite the mapping process through automated correlation of stereo data. Stereo correlation involves the comparison of radiance (brightness) signals or patterns recorded by sensors. Conventionally, two-dimensional area correlation is utilized but this is a rather slow and cumbersome procedure. Digital correlation can...