Geology and geochemistry of epithermal precious metal vein systems in the intra-oceanic arcs of Palau and Yap, western Pacific
J. J. Rytuba, W. R. Miller
1990, Journal of Geochemical Exploration (35) 413-447
The Palau and Yap arcs are part of an intra-oceanic island-arc-trench system which separates the Pacific and Philippine plates in the western Pacific Ocean. The 350-km-long Palau arc consists of over 200 islands while the 400-km-long Yap arc located to the north has only four major islands exposed. Four of...
Uranium-series dating of secondary carbonates near Yucca Mountain, Nevada. Applications to tectonic, paleoclimatic, and paleohydrologic problems
D.R. Muhs, J.W. Whitney, R. R. Shroba, E. M. Taylor, C. A. Bush
1990, Conference Paper
Near-surface accumulations of secondary carbonates are common in the soils and sediments of the Yucca Mountain area. These carbonates contain small amounts of uranium that allow dating by the uranium-series disequilibrium method. Preliminary results from the Yucca Mountain area indicate that the U-series methods can (1) identify multiple episodes of...
Optimum strong-motion array geometry for source inversion - II
M. Iida
1990, Earthquake Engineering and Structural Dynamics (19) 35-44
Optimum strong-motion array geometry for source inversions is determined for each of three types of earthquake faults: strike-slip, dip-slip and offshore subduction thrust. It is found that the complete Green's function is capable of stabilizing the accuracy of an inversion solution obtained using theoretical seismograms, regardless of the differences in...
Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions
Stuart Rojstaczer, Francis S. Riley
1990, Water Resources Research (26) 1803-1817
The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water...
Origin, structure, and evolution of a reattachment bar, Colorado River, Grand Canyon, Arizona
David M. Rubin, John C. Schmidt, Johnnie N. Moore
1990, Journal of Sedimentary Research (60) 982-991
In a channel expansion, flow can separate from the bank, creating a zone of relatively weak recirculating current. Bars that accumulate in this weak flow near the point where flow reattaches to the bank are called reattachment bars. As a reattachment bar evolves, the recirculation zone may fill with sediment...
High-precision 40Ar/39Ar sanidine geochronology of ignimbrites in the Mogollon-Datil volcanic field, southwestern New Mexico
W. C. McIntosh, J. F. Sutter, C.E. Chapin, L.L. Kedzie
1990, Bulletin of Volcanology (52) 584-601
40Ar/39Ar age spectra have been obtained from 85 sanidine separates from 36 ignimbrites and one rhyolitic lava in the latest Eocene-Oligocene Mogollon-Datil volcanic field of southwestern New Mexico. Of the 97 measured age spectra, 94 yield weighted-mean plateau ages each giving single-spectrum 1?? precision of??0.25%-0.4% (??0.07-0.14 Ma). Replicate plateau age...
Gabbroic xenoliths from the northern Gorda Ridge: Implications for magma chamber processes under slow spreading centers
A. S. Davis, D.A. Clague
1990, Journal of Geophysical Research Solid Earth (95) 10885-10905
Abundant gabbroic xenoliths in porphyritic pillow basalt were dredged from the northern Gorda Ridge. The host lava is a moderately fractionated, normal mid-ocean ridge basalt with a heterogeneous glass rind (Mg numbers 56-60). Other lavas in the vicinity range from near primary (Mg number 69) to fractionated (Mg number 56)....
Integration of potential-field and digital geologic data for two North American geoscience transects
J. D. Phillips
1990, Journal of Geological Education (38) 330-338
Two North American contributions to the Global Geoscience Transects Program, the Quebec-Maine-Gulf of Maine transect and the Great Lakes portion of the United States-Canadian Border transect, are among the first to produce digital geology in a form that can be combined with gridded gravity and aeromagnetic data. Maps of shaded...
A basic program to transform continuous polar dipole-dipole resistivity soundings to half-Schlumberger soundings
A. Zerilli, R.J. Bisdorf
1990, Computers & Geosciences (16) 911-923
An interactive HP 9845B BASIC program transforms continuous polar dipole-dipole resistivity soundings to half-Schlumberger soundings. The program features graphic presentation of the field dipole-dipole data as well as the transformed half-Schlumberger data. An example of the transformation and its effectiveness in smoothing "high-frequency" noise is given. ?? 1990....
Application of the DR3M watershed model on a small urban basin
Richard P. Thomas
1990, Water Resources Bulletin (26) 757-766
Data collected at a 79-acre urban watershed in Albuquerque, New Mexico, were used to calibrate and verify the Distributed Routing Rainfall-Runoff Model, a parametric watershed model. Standard errors of estimate for the 38 calibration storms were 33 percent and 38 percent, respectively, for volumes and peaks; and for the 46...
Thrust-ridge paleodepositional model for the Upper Freeport coal bed and associated clastic facies, Upper Potomac coal field, Appalachian Basin, U.S.A.
Edward S. Belt, P.C. Lyons
1990, International Journal of Coal Geology (16) 167-170
A blind-thrust-ridge model is proposed to explain the lack of coarse clastic material in the vast minable Upper Freeport coal bed (UF). This coal bed contains only fine elastic partings and is overlain by regionally extensive, closely spaced channel-belt deposits in...
Summit Lake landslide and geomorphic history of Summit Lake basin, northwestern Nevada
B. Brandon Curry, W.N. Melhorn
1990, Geomorphology (4) 1-17
The Summit Lake landslide, northwestern Nevada, composed of Early Miocene pyroclastic debris, Ashdown Tuff, and basalt and rhyolite of the Black Rock Range, blocked the upper Soldier Creek-Snow Creek drainage and impounded Summit Lake sometimes prior to 7840 yr B.P. The slide...
Potentiometric surface of the Edwards-Trinity aquifer system and contiguous hydraulically connected units, west-central Texas, winter, 1974-75
Eve L. Kuniansky
1990, Water-Resources Investigations Report 89-4208
The potentiometric surface of the Edwards-Trinity aquifer system and contiguous hydraulically connected units (from December 1974 through February 1975) was mapped as part of the Edwards-Trinity Regional Aquifer-System Analysis (RASA) project. A major goal of the Edwards-Trinity RASA project is to understand and describe the regional flow system (Bush, 1986)....
Error in telemetry studies: Effects of animal movement on triangulation
Joel A. Schmutz, Gary C. White
1990, Journal of Wildlife Management (54) 506-510
We used Monte Carlo simulations to investigate the effects of animal movement on error of estimated animal locations derived from radio-telemetry triangulation of sequentially obtained bearings. Simulated movements of 0-534 m resulted in up to 10-fold increases in average location error but <10% decreases in location precision when observer-to-animal distances...
Adsorption of benzene, toluene, and xylene by two tetramethylammonium-smectites having different charge densities
Jiunn-Fwu Lee, Max M. Mortland, Cary T. Chiou, Daniel E. Kite, Stephen A. Boyd
1990, Clays and Clay Minerals (38) 113-120
A high-charge smectite from Arizona [cation-exchange capacity (CEC) = 120 meq/100 g] and a low-charge smectite from Wyoming (CEC = 90 meq/100 g) were used to prepare homoionic tetramethylammonium (TMA)-clay complexes. The adsorption of benzene, toluene, and o-xylene as vapors by the dry TMA-clays and as solutes from water by...
Enzyme-linked immunosorbent assay compared with gas chromatography/mass spectrometry for the determination of triazine herbicides in water
E. Michael Thurman, Michael Meyer, Michael Pomes, Charles A. Perry, A. Paul Schwab
1990, Analytical Chemistry (62) 2043-2048
No abstract available....
Summer-fall survival of American woodcock in Maine
Eric L. Derleth, Greg F. Sepik
1990, Journal of Wildlife Management (54) 97-106
We estimated summer-fall (15 Jun-20 Oct) survival for 32 adult and 96 fledged young American woodcock (Scolopax minor) radiotagged in eastern Maine during 1982-84 using single-interval, multiple-interval, and nonparametric (product-limit) methods. Single-interval survival estimates were 0.90, 0.88, 0.57, and 0.73 for adult males, adult females, young males, and young females,...
The Pacific Northwest; linkage between earthquake and volcano hazards
R. S. Crosson
1990, Earthquakes & Volcanoes (USGS) (22) 219-225
AS the title of the magazine Earthquake and Volcanoes suggests, these two geological phenomena are often closely associated. Earthquakes frequently precede volcanic eruptions, and volcanoes are often sources of small to intermediate size earthquakes resulting from the movement of magma within the volcano's plumbing system. In the Pacific Northwest, the association between...
Origin of Florida Canyon and the role of spring sapping on the formation of submarine box canyons
Charles K. Paull, Fred N. Spiess, Joseph R. Curray, David C. Twichell
1990, Geological Society of America Bulletin (102) 502-515
Florida Canyon, one of a series of major submarine canyons on the southwestern edge of the Florida Platform, was surveyed using GLORIA, SeaBeam, and Deep-Tow technologies, and it was directly observed during three DSRV Alvin dives. Florida Canyon exhibits two distinct morphologies: a broad V-shaped upper canyon and a deeply entrenched, flat-floored,...
Quality and character of Pakistan Coal
Peter D. Warwick, Shahid Javed
A.H Kazmi, R.A. Siddiqi, editor(s)
1990, Book chapter, Significance of the coal resources of Pakistan
No abstract available....
Fluorescent polycyclic aromatic hydrocarbons as probes for studying the impact of colloids on pollutant transport in groundwater
Debera A. Backhus, Philip M. Gschwend
1990, Environmental Science & Technology (24) 1214-1223
No abstract available....
Trenching in the New Madrid seismic zone
D. P. Russ
1990, Earthquakes & Volcanoes (USGS) (22) 22-25
Trenching studies of the San Andreas fault have been of great value to geologists in California for determining not only the prehistoric occurrences of earthquakes on the fault bu also the age of these movements. In the New Madrid seismic zone, U.S Geological Survey scientists have been trenching across suspected...
Threat of an earthquake right under the capital in Japan
T. Rikitake
1990, Earthquakes & Volcanoes (USGS) (22) 209-210
Tokyo, Japan's capital, has been enjoying a seismically quiet period following the 1923 Kanto earthquake of magnitude 7.9 that killed more than 140,000 people. Such a quiet period seems likely to be a repetition of the 80-year quiescence after the great 1703 Genroku earthquake of magntidue 8.2 that occurred in...
The mass media and disasters
E. M. Rogers
1990, Earthquakes & Volcanoes (USGS) (22) 176-178
Past investigations by myself and others on the role of the mass media in disasters indicate that news people typically find themselves in situations of uncertainty, ambiguity, and conflicting information; the communication and transportation services that these people use in covering a story become inoperative. However, the media are expected...
Earthquakes, January-February 1990
W. J. Person
1990, Earthquakes & Volcanoes (USGS) (22) 179-182
There were no major earthquakes during the first 2 months of the year and there were no earthquake-related deaths reported during this same time period. In the United States a moderate earthquake on February 28 in southern California caused some minor injuries and considerable damage. ...
