A simple model of a phreatic surface through an earth dam
T. V. Hromadka II
1984, Advances in Water Resources (7) 141-143
A simple numerical model for estimating a phreatic surface in an earthen dam is presented. The numerical approach is based upon the Complex Variable Boundary Element Method (CVBEM). By expanding the CVBEM approximation geometric functions into a first order Taylor series, the unknown phreatic surface location geometrics can be approximated...
Creep behavior of submarine sediments
Armand J. Silva, J.S. Booth
1984, Geo-Marine Letters (4) 215-219
A series of experiments on drained creep of marine sediment indicates that strength degradation results from the creep process, which implies an associated reduction in slope stability. Furthermore, the highest creep potential of a sediment may be at its preconsolidation stress. Results from the experiments on samples from Georges Bank...
Thermal conductivity determinations on solid rock - a comparison between a steady-state divided-bar apparatus and a commercial transient line-source device
J.H. Sass, C. Stone, R. J. Munroe
1984, Journal of Volcanology and Geothermal Research (20) 145-153
Two apparatuses were used to measure thermal conductivities on pairs of contiguous samples from 17 specimens of solid rock: the USGS divided-bar apparatus, a steadystate comparative method, and the Shotherm "Quick Thermal Meter" (QTM), which employs a transient strip heat source. Both devices were calibrated relative to fused silica. Both...
U-Th-Pb, Rb-Sr, and Ar-Ar mineral and whole-rock isotopic systematics in a metamorphosed granitic terrane, southeastern California
E. Dewitt, R.L. Armstrong, J. F. Sutter, R. E. Zartman
1984, Geological Society of America Bulletin (95) 723-739
Mesozoic structural domes are developed in an older Proterozoic crystalline basement of granitic to granodioritic foliate metaplutonic rocks in the Halloran Hills, southeastern California. Isotopic analyses of whole rocks and mineral separates from these rocks by U-Th-Pb, Rb-Sr, and Ar-Ar techniques yield a...
Archaeological sedimentology of overbank silt deposits on the floodplain of the Ohio River near Louisville, Kentucky
H.H. Gray
1984, Journal of Archaeological Science (11) 421-432
The surface of the floodplain of the Ohio River about 20km southwest of Louisville, Kentucky, is a series of linear ridges and swales that are subparallel to the channel of the river, which here is relatively straight and flows southward. Numerous prehistoric occupational sites are located on these ridges. The...
APPLICATION OF AUDIO-MAGNETOTELLURIC SURVEYS ON SAO MIGUEL ISLAND, AZORES PORTUGAL.
Donald Hoover, A. Rodrigues Da Silva, Herbert A. Pierce, Roberto Amaral
1984, Conference Paper, Transactions - Geothermal Resources Council
Geothermal exploration and development has been under way on Sao Miguel Island, Azores since 1975. This work had been restricted to the Fogo volcano, one of three dormant silicic volcanic centers on the island. The USGS in 1982 and 1983 conducted reconnaissance natural-source audio-magnetotelluric (AMT) surveys of all three silicic...
Straczekite, a new calcium barium potassium vanadate mineral from Wilson Springs, Arkansas
H. T. Evans Jr., G. Nord, J. Marinenko, C. Milton
1984, Mineralogical Magazine (48) 289-293
Straczekite occurs as a rare secondary mineral in fibrous seams, along with other V minerals (A.M. 64-713), in ore from the vanadium mine in Wilson Springs (formerly Potash Sulfur Springs), Garland County, Arkansas. It forms soft, thin laths of dark greenish black crystals up to 0.5 mm in length. Indexed...
Peralkaline ash flow tuffs and calderas of the McDermitt Volcanic Field, southeast Oregon and north central Nevada
J. J. Rytuba, E.H. McKee
1984, Journal of Geophysical Research Solid Earth (89) 8616-8628
The McDermitt volcanic field covers an area of 20,000 km2 in southeastern Oregon and northwestern Nevada and consists of seven large-volume ash flow sheets that vented from 16.1 to 15 Ma ago. The volcanic field is characterized by peralkaline, high-silica rhyolite, and all but one of the sheets are comendites. The...
Subsurface injection of treated sewage into a saline-water aquifer at St. Petersburg, Florida - Aquifer pressure buildup
J.J. Hickey
1984, Ground Water (22) 48-55
The city of St. Petersburg has been testing subsurface injection of treated sewage into the Floridan aquifer as a means of eliminating discharge of sewage to surface waters and as a means of storing treated sewage for future nonpotable reuse. Treated sweage that had a mean chloride concentration of 170...
The isotope systematics of a juvenile intraplate volcano: Pb, Nd, and Sr isotope ratios of basalts from Loihi Seamount, Hawaii
H. Staudigel, A. Zindler, S.R. Hart, T. Leslie, C.-Y. Chen, D. Clague
1984, Earth and Planetary Science Letters (69) 13-29
Sr, Nd, and Pb isotope ratios for a representative suite of 15 basanites, alkali basalts, transitional basalts and tholeiites from Loihi Seamount, Hawaii, display unusually large variations for a single volcano, but lie within known ranges for Hawaiian basalts. Nd isotope...
PLANNING FOR OPTICAL DISK TECHNOLOGY WITH DIGITAL CARTOGRAPHY.
Donald L. Light
1984, Conference Paper
Progress in the computer field continues to suggest that the transition from traditional analog mapping systems to digital systems has become a practical possibility. A major shortfall that still exists in digital systems is the need for very large mass storage capacity. The decade of the 1980's has introduced laser...
Eulerian-Lagrangian solution of the convection-dispersion equation in natural coordinates
Ralph T. Cheng, Vincenzo Casulli, S. Nevil Milford
1984, Water Resources Research (20) 944-952
The vast majority of numerical investigations of transport phenomena use an Eulerian formulation for the convenience that the computational grids are fixed in space. An Eulerian-Lagrangian method (ELM) of solution for the convection-dispersion equation is discussed and analyzed. The ELM uses the Lagrangian concept in an Eulerian computational grid system....
Craggy Mountain Wilderness Study Area and Extension, North Carolina
Frank G. Lesure, Bradford B. Williams
1984, Book chapter, Wilderness mineral potential: assessment of mineral-resource potential in U.S. Forest Service lands studied in 1964-1984: Volume II (Professional Paper 1300)
Craggy Mountain Wilderness Study Area and the adjoining Craggy Mountain Extension consist of more than 4 sq mi of steep wooded slopes on the west side of Great Craggy Mountain in the Blue Ridge of western North Carolina. A mineral-resource survey of the area done between 1976 and 1979 found...
Relationship between quantity and quality of storm runoff and various watershed characteristics in Minnesota, USA
Rob G. Brown
1984, Conference Paper
Watersheds are rural areas undergoing urbanization with current urban land use comprising 4 to 58 percent of the watershed area. The quantity and quality of storm runoff in the watersheds was tested for correlations (significance level of 0. 05) with various land-surface features and landuse characteristics. Quantity of storm runoff...
Field and laboratory analyses of water from the Columbia aquifer in Eastern Maryland
L. J. Bachman
1984, Groundwater (22) 460-469
Field and laboratory analyses of pH, alkalinity, and specific conductance from water samples collected from the Columbia aquifer on the Delmarva Peninsula in eastern Maryland were compared to determine if laboratory analyses could be used for making regional water-quality interpretations.On the basis of 170 field...
Pedimentation versus debris-flow origin of plateau-side desert terraces in southern Utah
V. S. Williams
1984, Journal of Geology (92) 457-468
Plateau-side terraces in arid areas around the world are commonly described as pediment remnants, although, in many cases, they may have been formed by debris-flow deposition. Pediments do exist in the area of the Aquarius and Kaiparowits Plateaus of southern Utah; however, many alluvial terraces that were classified by previous...
Compton suppression gamma-counting: The effect of count rate
Hugh T. Millard Jr.
1984, Nuclear Instruments and Methods In Physics Research (223) 416-419
Past research has shown that anti-coincidence shielded Ge(Li) spectrometers enhanced the signal-to-background ratios for gamma-photopeaks, which are situated on high Compton backgrounds. Ordinarily, an anti- or non-coincidence spectrum (A) and a coincidence spectrum (C) are collected simultaneously with these systems. To be useful in neutron activation analysis (NAA), the fractions...
Dendrogeomorphic evidence of debris flow frequency and magnitude at Mount Shasta, California
Cliff R. Hupp
1984, Environmental Geology and Water Sciences (6) 121-128
Debris-flow deposits and woody vegetation adjacent to and growing within the channels of Whitney, Bolam, Mud, Ash, and Panthe creeks provide a 300-year record of debris-flow frequency at Mount Shasta Dendrochronologic (tree-ring) dating methods for the debris flows proved consistent with available documented records of debris flows Nine debris flows...
Glacier mass balance and runoff research in the U.S.A.
L.R. Mayo
1984, Geografiska Annaler, Series A (66 A) 215-227
Research on glacier mass balance began in the U.S.A. about 50 years ago. More complete studies of climate, snow and ice balance, and the hydrology of glaciers were initiated for the IGY in 1957 and the IHD in 1966. Investigations included the magnitude and geographic distribution of normal...
Botanical and geological significance of potassium-argon dates from the Juan Fernández Islands
Tod F. Stuessy, K.A. Foland, John F. Sutter, Roger W. Sanders, O. Mario Silva
1984, Science (225) 49-51
Potassium-argon dating of five basalts from the three main islands of the Juan Fernández (or Robinson Crusoe) Islands of Chile in the southeastern Pacific gives ages of 1.01 ± 0.12 and 2.44 ± 0.14 million years for Masafuera, 3.79 ± 0.20 and 4.23 ± 0.16 for Masatierra, and 5.8 ±...
Heating of a fully saturated Darcian half-space: Pressure generation, fluid expulsion, and phase change
P. Delaney
1984, International Journal of Heat and Mass Transfer (27) 1327-1335
Analytical solutions are developed for the pressurization, expansion, and flow of one- and two-phase liquids during heating of fully saturated and hydraulically open Darcian half-spaces subjected to a step rise in temperature at its surface. For silicate materials, advective transfer is commonly unimportant in the liquid region; this is not...
Chemical determination of particulate nitrogen in San Francisco Bay. A comparison of two estimates
S.W. Hager, D.D. Harmon
1984, Estuarine, Coastal and Shelf Science (19) 181-191
Particulate nitrogen was measured by both the ultra-violet light-catalyzed peroxide method and the high temperature combustion method. The difference between values obtained with the two methods (combustion minus UV) was found to be linearly correlated with the concentration of total suspended particulate matter (SPM) in the sample. The slope of...
The group separation of the rare-earth elements and yttrium from geologic materials by cation-exchange chromatography
J.G. Crock, F.E. Lichte, T.R. Wildeman
1984, Chemical Geology (45) 149-163
Demand is increasing for the determination of the rare-earth elements (REE) and yttrium in geologic materials. Due to their low natural abundance in many materials and the interferences that occur in many methods of determination, a separation procedure utilizing gradient strong-acid cation-exchange chromatography is often used to preconcentrate and isolate...
Geology of El Chichon volcano, Chiapas, Mexico
W. A. Duffield, R.I. Tilling, R. Canul
1984, Journal of Volcanology and Geothermal Research (20) 117-132
The (pre-1982) 850-m-high andesitic stratovolcano El Chicho??n, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, Me??xico. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chicho??n is built on Tertiary siltstone and sandstone,...
Midseason mapping of sunflowers using Landsat digital data
W.H. Anderson, D.O. Ohlen, S.D. Fairaizl
1984, Journal of Wildlife Management (48) 295-298
The mapping results suggest that for the midsummer Landsat data used, there was not a sufficiently reliable relationship between Landsat-derived spectral clusters and sunflowers to allow 'automated' production of useful sunflower location maps. The occurrence of sunflower pixels in all cluster classes was a consequence of the diversity in sunflower...
