Imaging the Juan de Fuca plate beneath southern Oregon using teleseismic P wave residuals
R.A. Harris, H. M. Iyer, P.B. Dawson
1991, Journal of Geophysical Research (96) 19879-19889
The Juan de Fuca plate subducts under the western margin of the North American plate in southern British Columbia, Washington, Oregon, and northern California. Benioff zone seismicity delineates shallow parts of the plate in Washington and northern California, whereas in Oregon there is a lack of...
Scale, variable density, and conservation planning for mammalian carnivores
C. Schonewald-Cox, R. Azari, S. Blume
1991, Conservation Biology (5) 491-495
Many mammalian carnivores are in local or global decline. To slow this process, continued planning to protect these species is warranted, Still, the data bases that we have at our disposal do not adequately document population requirements for space at scales appropriate for conservation planning. To illustrate this problem, we...
Stress magnitudes in the crust: constraints from stress orientation and relative magnitude data
M.L. Zoback, M. Magee
1991, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (337) 181-194
The World Stress Map Project is a global cooperative effort to compile and interpret data on the orientation and relative magnitudes of the contemporary in situ tectonic stress field in the Earth's lithosphere. The intraplate stress field in both the oceans and continents is largely compressional with one or both...
New evidence on the hydrothermal system in Long Valley caldera, California, from wells, fluid sampling, electrical geophysics, and age determinations of hot-spring deposits
M.L. Sorey, G.A. Suemnicht, N.C. Sturchio, G.A. Nordquist
1991, Journal of Volcanology and Geothermal Research (48) 229-263
Data collected since 1985 from test drilling, fluid sampling, and geologic and geophysical investigations provide a clearer definition of the hydrothermal system in Long Valley caldera than was previously available. This information confirms the existence of high-temperature (> 200??C) reservoirs within the volcanic fill in parts of the west moat....
Anatomy of a metamorphic core complex: seismic refraction/wide-angle reflection profiling in southeastern California and western Arizona
J. McCarthy, S.P. Larkin, G. S. Fuis, R.W. Simpson, K. A. Howard
1991, Journal of Geophysical Research (96) 12259-12291
The metamorphic core complex belt in southeastern California and western Arizona is a NW-SE trending zone of unusually large Tertiary extension and uplift. Midcrustal rocks exposed in this belt raise questions about the crustal thickness, crustal structure, and the tectonic evolution of the region. Three...
Late Laramide thrust-related and evaporite-domed anticlines in the southern Piceance Basin, northeastern Colorado Plateau
M. A. Grout, G. A. Abrams, R. L. Tang, T. J. Hainsworth, E.R. Verbeek
1991, American Association of Petroleum Geologists Bulletin (75) 205-218
New seismic and gravity data across the hydrocarbon-producing Divide Creek and Wolf Creek anticlines in the southern Piceance basin reveal contrasting styles of deformation within two widely separated time frames. Seismic data indicate that prebasin Paleozoic deformation resulted in block faulting of the Precambrian crystalline basement rocks and overlying Cambrian...
Volcanic eruptions; energy and size
S. de la Cruz-Reyna
1991, Earthquakes & Volcanoes (USGS) (22) 140-141
The Earth is a dynamic planet. Many different processes are continuously developing, creating a delicate balance between the energy stored and generated in its interior and the heat lost into space. The heat in continuously transferred through complex self-regulating convection mechanisms on a planetary scale. The distribution of terrestrial heat...
Sources of dissolved and particulate organic material in Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA
Jill Baron, Diane M. McKnight, A. Scott Denning
1991, Biogeochemistry (15) 89-110
The sources of both dissolved organic carbon (DOC) and particulate organic carbon (POC) to an alpine (Sky Pond) and a subalpine lake (The Loch) in Rocky Mountain National Park were explored for four years. The importance of both autochthonous and allochthonous sources of organic matter differ, not only between alpine...
An exact solution of solute transport by one-dimensional random velocity fields
V.D. Cvetkovic, G. Dagan, A.M. Shapiro
1991, Stochastic Hydrology and Hydraulics (5) 45-54
The problem of one-dimensional transport of passive solute by a random steady velocity field is investigated. This problem is representative of solute movement in porous media, for example, in vertical flow through a horizontally stratified formation of variable porosity with a constant flux at the soil surface. Relating moments of...
The Reaction Titanite+Kyanite=Anorthite+Rutile and Titanite-Rutile Barometry in Eclogites
C.F. Manning, S.R. Bohlen
1991, Contributions to Mineralogy and Petrology (109) 1-9
Titanite and rutile are a common mineral pair in eclogites, and many equilibria involving these phases are potentially useful in estimating pressures of metamorphism. We have reversed one such reaction, {Mathematical expression} using a piston-cylinder apparatus. Titanite+kyanite is the high-pressure assemblage and our results locate the equilibrium between 15.5 15.9,...
Regional hydrogeological screening characteristics used for siting near-surface waste-disposal facilities in Oklahoma, U.S.A.
K.S. Johnson
1991, Environmental Geology and Water Sciences (17) 3-7
The Oklahoma Geological Survey has developed several maps and reports for preliminary screening of the state of Oklahoma to identify areas that are generally acceptable or unacceptable for disposal of a wide variety of waste materials. These maps and reports focus on the geologic and hydrogeologic parameters that must be...
S-layer positive motile aeromonads isolated from channel catfish
L.A. Ford
1991, Journal of Wildlife Diseases (27) 557-561
Motile aeromonads are ubiquitous aquatic bacteria that can cause motile aeromonad septicemia (MAS), a disease which affects channel catfish and can produce significant economic loss. Motile aeromonads isolated from commercially-raised channel catfish were screened for production of S-layer protein in order to evaluate...
Application of ground-penetrating-radar methods in hydrogeologic studies
Milan Beres Jr., F.P. Haeni
1991, Ground Water (29) 375-386
A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well...
Subalkaline andesite from Valu Fa Ridge, a back-arc spreading center in southern Lau Basin: petrogenesis, comparative chemistry, and tectonic implications
T.L. Vallier, G.A. Jenner, F.A. Frey, J.B. Gill, A. S. Davis, A.M. Volpe, J.W. Hawkins, J.D. Morris, Peter A. Cawood, J. L. Morton, D.W. Scholl, M. Rautenschlein, W.M. White, Ross W. Williams, A.J. Stevenson, L. D. White
1991, Chemical Geology (91) 227-256
Tholeiitic andesite was dredged from two sites on Valu Fa Ridge (VFR), a back-arc spreading center in Lau Basin. Valu Fa Ridge, at least 200 km long, is located 40-50 km west of the active Tofua Volcanic Arc (TVA) axis and lies about 150 km above the subducted oceanic plate....
Geochemistry of a Tertiary sedimentary phosphate deposit: Baja California Sur, Mexico
D.Z. Piper
1991, Chemical Geology (92) 283-316
The San Gregorio Formation in Baja California Sur, a phosphate-enriched sedimentary unit of late Oligocene to early Miocene age, has been analyzed in two areas (La Purisima and San Hilario) for its chemical composition (major oxides, Cu, Cd, Cr, Co, V, and rare-earth elements - REE) and isotopic composition (??18O...
Real-time Seismic Amplitude Measurement (RSAM): a volcano monitoring and prediction tool
E.T. Endo, T. Murray
1991, Bulletin of Volcanology (53) 533-545
Seismicity is one of the most commonly monitored phenomena used to determine the state of a volcano and for the prediction of volcanic eruptions. Although several real-time earthquake-detection and data acquisition systems exist, few continuously measure seismic amplitude in circumstances where individual events are difficult to recognize or where volcanic...
Origin of xenoliths in the trachyte at Puu Waawaa, Hualalai Volcano, Hawaii
David A. Clague, Wendy A. Bohrson
1991, Contributions to Mineralogy and Petrology (108) 439-452
Rare dunite and 2-pyroxene gabbro xenoliths occur in banded trachyte at Puu Waawaa on Hualalai Volcano, Hawaii. Mineral compositions suggest that these xenoliths formed as cumulates of tholeiitic basalt at shallow depth in a subcaldera magma reservoir. Subsequently, the minerals in the xenoliths underwent subsolidus reequilibration that particularly affected chromite...
Surface features of central North America: a synoptic view from computer graphics
R.J. Pike
1991, GSA Today (1) 1-251
A digital shaded-relief image of the 48 contiguous United States shows the details of large- and small-scale landforms, including several linear trends. The features faithfully reflect tectonism, continental glaciation, fluvial activity, volcanism, and other surface-shaping events and processes. The new map not only depicts topography accurately and in its true...
Influence of feeding rate on performance of Atlantic salmon fry in an ozonated water reuse system
H. A. Poston, R.C. Williams
1991, Progressive Fish-Culturist (53) 111-113
A 4‐week trial was conducted to determine the optimal feeding level in percent body weight of a commercially prepared, practical diet for early feeding fry of Atlantic salmon (Salmo salar) in an ozonated water reuse system at 17–18°C. Triplicate groups of swimup (0.19‐g) fry were fed one of seven levels...
Heavy metal contamination of sediments in the upper connecting channels of the Great Lakes
S. Jerrine Nichols, Bruce A. Manny, Donald W. Schloesser, Thomas A. Edsall
1991, Hydrobiologia (219) 307-315
In 1985, sampling at 250 stations throughout the St. Marys, St. Clair, and Detroit rivers and Lake St. Clair — the connecting channels of the upper Great Lakes — revealed widespread metal contamination of the sediments. Concentrations of cadmium, chromium, copper, lead, mercury, nickel, and zinc each exceeded U.S. Environmental...
Isolation of poxvirus from debilitating cutaneous lesions on four immature grackles (Quiscalus sp.)
D. E. Docherty, R.I.R. Long, Edward L. Flickinger, L. N. Locke
1991, Avian Diseases (35) 244-247
Poxvirus was isolated from nodules on four immature grackles (Quiscalus sp.) collected in two residential areas of Victoria, Texas. All of the birds were emaciated and had nodules on the eyelids, bill, legs, toes, and areas of the skin on the wings, neck, and ventral abdomen. These pox nodules were...
Anomalous folds associated with the east-central part of the Garlock Fault, southeast California
G.I. Smith
1991, Geological Society of America Bulletin (103) 615-624
The east-central part of the left-lateral Garlock fault, in southeast California, is associated with three broad folds that trend and plunge northeast. The folds, which lie north, south, and astride the fault, postdate deposition of alluvial gravels that at one time formed a continuous northwest-sloping fan; the gravels rest conformably...
Sources and magnitude of bias associated with determination of polychlorinated biphenyls in environmental samples
Robert P. Eganhouse, R. W. Gossett
1991, Analytical Chemistry (63) 2130-2137
Recently compiled data on the composition of commercial Aroclor mixtures and ECD (electron capture detector) response factors for all 209 PCB congeners are used to develop estimates of the bias associated with determination of polychlorinated blphenyis. During quantitation of multlcomponent peaks by congener-specific procedures error is introduced because of variable...
Flight performance energetics and water turnovers of Tippler Pigeons with a harness and doorsal load
James A. Gessaman, Gar W. Workman, Mark R. Fuller
1991, The Condor (93) 546-554
We measured carbon dioxide production and water efflux of 12 tippler pigeons (Columba spp.) during seven experimental flights using the doubly labeled water (DLW) method. Prior to the experiment birds were randomly assigned to one of two groups. One group flew as controls (no load or harness) on all...
The high-pressure electronic structure of magnesiowustite (Mg, Fe)O: applications to the physics and chemistry of the lower mantle
David M. Sherman
1991, Journal of Geophysical Research (96) 14299-14312
The electronic structure of magnesiowustite is investigated using self-consistent field Xα scattered wave (SCF-Xα-SW) molecular orbital calculations on (FeO6)10− and (FeMg12O14)2− clusters. Calculated one-electron transition energies are used to interpret the optical spectrum of (Mg, Fe)O. The results are applied to the electrical and thermal conductivity of the lower...
