Assessment of long-term salinity changes in an irrigated stream-aquifer system
Leonard F. Konikow, Mark Person
1985, Water Resources Research (21) 1611-1624
Changes in salinity in groundwater and surface water in the Arkansas River valley of southeastern Colorado are primarily related to irrigation practices. A solute transport model was applied to an 11-mile reach of the valley to compute salinity changes in response to spatially and temporally varying stresses. The model was...
Geochemistry of groundwater in Cretaceous sediments of the southeastern coastal plain of eastern Mississippi and western Alabama
Roger W. Lee
1985, Water Resources Research (21) 1545-1556
Geochemical samples of waters along two hydrologic flow paths in four Upper Cretaceous aquifers of northeastern Mississippi and western Alabama indicate similar geochemical evolution of their respective waters. The waters of the Coker, Gordo, and Eutaw-McShan aquifers, noncalcareous sands, increase downgradient in dissolved solids and pH, and are dominated by sodium...
Absolute calibration of Landsat instruments using the moon.
H. H. Kieffer, R.L. Wildey
1985, Photogrammetric Engineering and Remote Sensing (51) 1391-1393
A lunar observation by Landsat could provide improved radiometric and geometric calibration of both the Thematic Mapper and the Multispectral Scanner in terms of absolute radiometry, determination of the modulation transfer function, and sensitivity to scattered light. A pitch of the spacecraft would be required. -Authors...
Drainage development of the Green River Basin in southwestern Wyoming and its bearing on fish biogeography, neotectonics, and paleoclimates.
W. R. Hansen
1985, Mountain Geologist (22) 192-204
The Upper Green River flows southward out of the Green River Basin through a series of deep canyons across the Uinta Mountains in a course that post-dates the deposition of the Bishop Conglomerate (Oligocene). After the Eocene lakes disappeared, drainage was generally eastward across the present Continental Divide, until the...
Lacustrine-humate model for primary uranium ore deposits, Grants uranium region, New Mexico
C. E. Turner-Peterson
1985, American Association of Petroleum Geologists Bulletin (69) 1990-2020
Two generations of uranium ore, primary and redistributed, occur in fluvial sandstones of the Upper Jurassic Morrison Formation in the San Juan basin; the two stages of ore formation can be related to the hydrologic history of the basin. Primary ore formed soon after Morrison deposition, in the Late Jurassic...
Saprolite formation beneath Coastal Plain sediments near Washington, D.C.
M.J. Pavich, S. F. Obermeier
1985, Geological Society of America Bulletin (96) 886-900
Crystalline rocks buried beneath Atlantic Coastal Plain sediments in the Washington, D.C., area commonly have weathering profiles that resemble exposed saprolite of the Piedmont. Cuts along the Washington Metropolitan Area Transit Authority (WMATA) route in northern Virginia show a bedrock weathering profile beneath Cretaceous and younger sediments.Three lines of evidence...
Vent evolution and lag breccia formation during the Cape Riva eruption of Santorini, Greece
T. H. Druitt
1985, Journal of Geology (93) 439-454
The 18,500 yr. b.p. Cape Riva (CR) eruption of Santorini vented several km3 or more of magma, generating four eruption units: a basal Plinian fall deposit (CR-A) and three pyroclastic flow deposits (CR-B to CR-D upwards). CR-B and CR-D are welded ignimbrites; CR-C consists predominantly of up to 25 m...
Electrical geophysical investigations of massive sulfide deposits and their host rocks, West Shasta copper-zinc district
R. J. Horton, B. D. Smith, J.C. Washburne
1985, Economic Geology (80) 2213-2229
The West Shasta copper-zinc district, Shasta County, California, contains many volcanogenic sulfide deposits within Middle Devonian rhyolites that have not been highly metamorphosed. The district was selected by the U.S. Geological Survey for intensive geological, geochemical, and geophysical study under the Development of Assessment Techniques (DAT) project because accessible exposures...
Root zone of the late Proterozoic Salma caldera, northeastern Arabian Shield, Kingdom of Saudi Arabia
K.S. Kellogg
1985, Journal of Geophysical Research Solid Earth (90) 11253-11262
The eroded root of the late Proterozoic Salma caldera crops out in a striking, roughly elliptical feature, about 27 km long and 22 km wide, near the northeastern edge of the Arabian Shield. The caldera is genetically part of an elongate alkalic granitic massif (Jabal Salma) that extends 35 km...
Proximal bedded deposits related to pyroclastic flows of May 18, 1980, Mount St. Helens, Washington
P. D. Rowley, N. S. MacLeod, M. A. Kuntz, A.M. Kaplan
1985, Geological Society of America Bulletin (96) 1373-1383
Thin-bedded, dacitic, pumiceous pyroclastic-flow deposits partly cover the steep northern flank of Mount St. Helens volcano, Washington. They are termed proximal bedded pyroclastic-flow (PBPF) deposits and were formed during the eruption of May 18, 1980. These unconsolidated deposits, as much as 20 m thick, are characterized by well-defined, chiefly plane-parallel...
Streamflow variability in the United States: 1931-1978.
H.F. Lins
1985, Journal of Climate and Applied Meteorology (24) 463-471
Systematic modes of spatial and temporal variation in a 48-year record of streamflow are defined using principal components. The components were calculated from a matrix of annual streamflow departures for 106 grid cells covering the United States in the years 1931-78. Five statistically significant components are found to account for...
Saudi Arabian seismic-refraction profile: A traveltime interpretation of crustal and upper mantle structure
Walter D. Mooney, M. E. Gettings, H. R. Blank, J. H. Healy
1985, Tectonophysics (111) 173-246
The crustal and upper mantle compressional-wave velocity structure across the southwestern Arabian Shield has been investigated by a 1000-km-long seismic refraction profile. The profile begins in Mesozoic cover rocks near Riyadh on the Arabian Platform, trends southwesterly across three major Precambrian tectonic provinces, traverses Cenozoic rocks of the coastal plain...
The National Cartographic Information Center: An information resource on mapping products for the nation
Alan R. Stevens
1985, Science and Technology Libraries (5) 25-38
Since its inception in 1974 the National Cartographic Information Center (NCIC), U.S. Geological Survey, has rapidly developed to become a focial point for providing information on the availability of cartographic data, including maps/charts, aerial photographics, satellite imagery, geodetic control, digitial mapping data, map materials and related cartographic products. In early...
Character and regional significance of Great Falls tectonic zone, east-central Idaho and west-central Montana
J. Michael O’Neill, David A. Lopez
1985, American Association of Petroleum Geologists Bulletin (69) 437-447
The Great Falls tectonic zone, here named, is a belt of diverse northeast-trending geologic features that can be traced from the Idaho batholith in the Cordilleran miogeocline, across thrust-belt structures and basement rocks of west-central and southwestern Montana, through cratonic rocks of central Montana, and into southwesternmost Saskatchewan, Canada. Geologic...
Degassing-induced crystallization of basaltic magma and effects on lava rheology
P. W. Lipman, N.G. Banks, J.M. Rhodes
1985, Nature (317) 604-607
During the north-east rift eruption of Mauna Loa volcano, Hawaii, on 25 March-14 April 1984 (Fig. 1), microphenocryst contents of erupted lava increased from 0.5 to 30% without concurrent change in either bulk magma composition or eruption temperature (1,140 ?? 3 ??C). The crystallization of the microphenocrysts is interpreted here...
A nomogram for interpreting slope stability of fine-grained deposits in modern and ancient-marine environments.
J.S. Booth, D.A. Sangrey, J.K. Fugate
1985, Journal of Sedimentary Petrology (55) 29-36
Design of the nomogram is based on effective stress and combines consolidation theory as applicable to depositional environments with the infinite-slope model of slope-stability analysis. The link between the two combined theories is a term representing the effective overburden stress, which may be...
A reconnaissance Rb-Sr, Sm-Nd, U-Pb, and K-Ar study of some host rocks and ore minerals in the West Shasta Cu- Zn district, California
R. W. Kistler, E.H. McKee, K. Futa, Z. E. Peterman, R. E. Zartman
1985, Economic Geology (80) 2128-2135
The Copley Greenstone, Balaklala Rhyolite, and Mule Mountain stock in the West Shasta Cu-Zn district, California, have Rb-Sr, Sm-Nd, U-Pb, and K-Ar systematics that indicate they are a cogenetic suite of ensimatic island-arc rocks about 400 m.y. Pervasive alteration and mineralization of these rocks, for the most part, was syngenetic...
The role of erosion by fish in shaping topography around Hudson submarine canyon.
D.C. Twichell, Craig B. Grimes, R. S. Jones, K.W. Able
1985, Journal of Sedimentary Petrology (55) 712-719
An 800-km 2 area of rough topography around the head of Hudson Canyon off the eastern United States is attributed to erosion by tilefish ( Lopholatilus chamaeleonticeps ) and associated species of crustaceans. The rough topography has a relief of 1-10 m, occurs in water depths of 120-500 m, and has been...
Possible precipitation of ice at low latitudes of Mars during periods of high obliquity
B. M. Jakosky, M. H. Carr
1985, Nature (315) 559-561
Most of the old cratered highlands of Mars are dissected by branching river valleys that appear to have been cut by running water1,2 yet liquid water is unstable everywhere on the martian surface. In the equatorial region, where most of the valleys are observed, even ice is unstable3,4. It has...
Limnocythere bradburyi n.sp.: a modern ostracode from central Mexico and a possible Quaternary paleoclimatic indicator
R. M. Forester
1985, Journal of Paleontology (59) 8-20
Limnocythere bradburyi is a new species of nonmarine ostracode that is living in several lakes in the central Mexican Plateau. These lakes are shallow, turbid, and pan-shaped, having relatively unstable and fluid substrates. Water levels of these lakes are high in the summer and low or dry in the winter....
Seasonal variation in sediment transport on the Russian River shelf, California
D.E. Drake, D.A. Cacchione
1985, Continental Shelf Research (4) 495-514
Near-bottom currents, light transmission and scattering, and bottom pressure were measured with GEOPROBE tripods and vector-averaging current meters during June 1979 to April 1980 on the central shelf 10 km west of the Russian River, California. The instruments were located on the mid-shelf mud belt composed of bimodal sandy clayey...
Apatitic connecting rings in moulds of Baculites sp. from the middle part of the Smoky Hill Member, Niobrara Chalk (Santonian), of western Kansas
W.A. Hasenmueller, D.E. Hattin
1985, Cretaceous Research (6) 317-330
Moulds of Baculites sp. are common in the Smoky Hill Member but only five known specimens contain connecting rings that have been preserved because of mineralisation by carbonate apatite. Analysis of four of these specimens suggests that the connecting rings were originally composed of organic material and were mineralised during early diagenesis....
Determination of carbonate carbon in geological materials by coulometric titration
E.E. Engleman, L. L. Jackson, D. R. Norton
1985, Chemical Geology (53) 125-128
A coulometric titration is used for the determination of carbonate carbon in geological materials. Carbon dioxide is evolved from the sample by the addition of 2 M perchloric acid, with heating, and is determined by automated coulometric titration. The coulometric titration showed improved speed and precision with comparable accuracy to...
Digital to Analog Conversion and Visual Evaluation of Thematic Mapper Data
James R. McCord, Douglas R. Binnie, Paul M. Seevers
1985, Journal of Imaging Technology (11) 125-130
As a part of the National Aeronautics and Space Administration Landsat D Image Data Quality Analysis Program, the Earth Resources Observation Systems Data Center (EDC) developed procedures to optimize the visual information content of Thematic Mapper data and evaluate the resulting photographic products by visual interpretation. A digital-to-analog transfer function...
Morphology of the Ebro fan valleys from SeaMARC and sea beam profiles
B. Alonso, K.A. Kastens, A. Maldonado, A. Malinverno, C.H. Nelson, S. O'Connell, A. Palanques, William B. F. Ryan
1985, Geo-Marine Letters (5) 141-148
The northern continental slope off the Ebro Delta has a badland topography indicating major slope erosion and mass movement of material that deposits sediment into a ponded lobe. The southern slope has a low degree of mass movement activity and slope valleys feed channel levee-complexes on a steep continental rise....
