Pb, Nd, and Sr isotopic evidence for a multicomponent source for rocks of Cook-Austral Islands and heterogeneities of mantle plumes
Y. Nakamura, M. Tatsumoto
1988, Geochimica et Cosmochimica Acta (52) 2909-2924
Sr, Nd, and Pb isotopic compositions were measured in alkaline volcanic rocks (alkali basalt, ankaramite, nephelinite, phonolite, and trachyte) from the South Cook Islands (Aitutaki, Mauke, Rarotonga, Atiu, and Mangaia) and the Austral Islands (Rimatara and Rurutu). The results show that the Cook-Austral rocks have an extremely wide range in...
The mechanics and three-dimensional internal structure of active magmatic systems: Kilauea volcano, Hawaii
M.P. Ryan
1988, Journal of Geophysical Research Solid Earth (93) 4213-4248
Interpretation of abundant seismic data suggests that Kilauea's primary conduit within the upper mantle is concentrically zoned to about 34-km depth. This zoned structure is inferred to contain a central core region of relatively higher permeability, surrounded by numerous dikes that are in intermittent hydraulic communication with each other and...
Power formula for open-channel flow resistance
Cheng-lung Chen
1988, Conference Paper
This paper evaluates various power formulas for flow resistance in open channels. Unlike the logarithmic resistance equation that can be theoretically derived either from Prandtl's mixing-length hypothesis or von Karman's similarity hypothesis, the power formula has long had an appearance of empiricism. Nevertheless, the simplicity in the form of the...
The global distribution, abundance, and stability of SO2 on Io
A. S. McEwen, T. V. Johnson, D. L. Matson, L.A. Soderblom
1988, Icarus (75) 450-478
Sulfur dioxide distribution and abundances, bolometric hemispheric albedos, and passive surface temperatures on Io are modeled and mapped globally from Voyager multispectral mosaics, Earth-based spectra, and photometric descriptions. Photometric models indicate global average values for regolith porosity of 75-95% and macroscopic roughness with a mean slope angle of ~30??. Abundances...
Retardations in fault creep rates before local moderate earthquakes along the San Andreas fault system, central California
Robert O. Burford
1988, Pure and Applied Geophysics PAGEOPH (126) 499-529
Records of shallow aseismic slip (fault creep) obtained along parts of the San Andreas and Calaveras faults in central California demonstrate that significant changes in creep rates often have been associated with local moderate earthquakes. An immediate postearthquake increase followed by gradual, long-term decay back to a previous background rate...
Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model
Antonius Laenen, R. P. Hansen
1988, Water-Resources Investigations Report 88-4004
A one-dimensional, unsteady-state, open-channel model was used to analytically reproduce three lahar events. Factors contributing to the success of the modeling were: (1) the lahars were confined to a channel, (2) channel roughness was defined by field information, and (3) the volume of the flow remained relatively unchanged for the...
Elastic-wave propagation and site amplification in the Salt Lake Valley, Utah, from simulated normal faulting earthquakes
H.M. Benz, R. B. Smith
1988, Bulletin of the Seismological Society of America (78) 1851-1874
The two-dimensional seismic response of the Salt Lake valley to near- and far-field earthquakes has been investigated from simulations of vertically incident plane waves and from normal-faulting earthquakes generated on the basin-bounding Wasatch fault. The response to normal faulting earthquakes was simulated using a two-dimensional finite-element method and the plane-wave...
Stable isotope geochemistry of sphalerite and other mineral matter in coal beds of the Illinois and Forest City basins
J. F. Whelan, J.C. Cobb, R. O. Rye
1988, Economic Geology (83) 990-1007
Cleat and clastic dikes of Middle Pennsylvanian-age coal beds of the Illinois and Forest City basins of Illinois, Iowa, Missouri, and Kansas locally contain appreciable amounts of sphalerite within a kaolinite-pyrite-sphalerite (+ or - pyrite)-calcite paragenetic sequence. The sphalerite and associated minerals are of interest as a partial record of...
An oxygen isotope and geochemical study of meteoric-hydrothermal systems at Pilot Mountain and selected other localities, Carolina slate belt
T. L. Klein, R.E. Criss
1988, Economic Geology (83) 801-821
Several epigenetic mineral deposits in the Ca1rolina slate belt are intimately related to meteoric-hydrothermal systems of late Precambrian and early Paleozoic age. At Pilot Mountain, low 18 O rocks correlate well with zones of strong silicic alteration and alkali leaching accompanied by high alumina minerals (sericite, pyrophyllite, andalusite + or - topaz)...
Applying the population/area model for planning of large mammal translocations
C. Schonewald-Cox, R.J. Baker, J.W. Bayless
L. Nielsen, R.D. Brown Jr., editor(s)
1988, Translocation of Wild Animals. 52-63
No abstract available at this time...
Detailed record of SO2 emissions from Pu'u `O`o between episodes 33 and 34 of the 1983-86 ERZ eruption, Kilauea, Hawaii
T.A. Chartier, William I. Rose Jr., J. B. Stokes
1988, Bulletin of Volcanology (50) 215-228
A tripod-mounted correlation spectrometer was used to measure SO2 emissions from Pu`u `O`o vent, mid-ERZ, Kilauea, Hawaii between Episodes 33 and 34 (June 13 to July 6, 1985). In 24 repose days, 906 measurements were collected, averaging 38 determinations/day. Measurements reflect 13% of the total 576 hours of the repose...
A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies
P. Switzer, J.W. Harden, R. K. Mark
1988, Mathematical Geology (20) 49-61
A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties...
Vapor-dominated zones within hydrothermal systems: Evolution and natural state
S. E. Ingebritsen, M.L. Sorey
1988, Journal of Geophysical Research Solid Earth (93) 13635-13655
Three conceptual models illustrate the range of hydrothermal systems in which vapor-dominated conditions are found. The first model (model I) represents a system with an extensive near-vaporstatic vapor-dominated zone and limited liquid throughflow and is analogous to systems such as The Geysers, California. Such systems can evolve within low-permeability barriers...
The growth of geological structures by repeated earthquakes: 2, Field examples of continental dip-slip faults
R.S. Stein, G.C.P. King, J. B. Rundle
1988, Journal of Geophysical Research Solid Earth (93) 13319-13331
A strong test of our understanding of the earthquake cycle is the ability to reproduce extant fault-bounded geological structures, such as basins and ranges, which are built by repeated cycles of deformation. Along strike-slip faults, the coseismic and interseismic deformation can be nearly equal in magnitude and opposite in sign,...
An Angus/Argo study of the neovolcanic zone along the East Pacific rise from the Clipperton fracture zone to 12°N
E. Uchupi, W. C. Schwab, Richard D. Ballard, J.L. Cheminee, Jean Francheteau, R. Hekinian, D.K. Blackman, Haraldur Sigurdsson
1988, Geo-Marine Letters (8) 131-138
Still photographs and video images collected along the Neovolcanic Zone of the East Pacific Rise from 10°15′N to 11°53′N show that recent volcanic sheet flows, possibly less than 100 years old, are superimposed on an older sediment-laden pillow terrane. This recent activity is restricted to a narrow zone that crosses...
Applications of a simulation model to decisions in mallard management
L.M. Cowardin, Douglas H. Johnson, T.L. Shaffer, D. W. Sparling
1988, Fish and Wildlife Technical Report 17
A system comprising simulation models and data bases for habitat availability and nest success rates was used to predict results from a mallard (Anas platyrhynchos) management plan and to compare six management methods with a control. Individual treatments in the applications included land purchase for waterfowl production, wetland easement purchase,...
Three-dimensional gravity modeling of the geologic structure of Long Valley caldera
S. F. Carle
1988, Journal of Geophysical Research Solid Earth (93) 13237-13250
A 48-mGal gravity low coincides with Long Valley caldera and is mainly attributed to low-density caldera fill. Gravity measurements by Unocal Geothermal have been integrated with U.S. Geological Survey data, vastly improving gravity station coverage throughout the caldera. A strong regional gravity trend is mainly attributed to isostasy. A “best...
Depositional models for two Tertiary coal-bearing sequences in the Powder River Basin, Wyoming, USA
Peter D. Warwick, Ronald W. Stanton
1988, Journal of the Geological Society (145) 613-620
Depositional controls on peat-forming environments which produce thick (>10m) coal beds can be inferred from relationships between coal bed geometry, maceral composition and associated lithologies. Study of these relationships within sedimentary sequences associated with the Wyodak-Anderson (Palaeocene) and the Felix (Eocene) sub-bituminous coal beds in the Powder River Basin,...
Regional assessment of pumpage in southeastern Virginia
Pixie A. Hamilton
1988, Conference Paper
A U.S. Geological Survey investigation was conducted, in cooperation with the Virginia Water Control Board, to analyze the hydrogeology and groundwater flow system in the Coastal Plain physiographic province of southeastern Virginia, and to assess the continued reliability of groundwater as a freshwater resource. To provide a more detailed analysis...
Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California
C. Sanders, P. Ho-Liu, D. Rinn, Kanamori Hiroo
1988, Journal of Geophysical Research Solid Earth (93) 3321-3338
We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of eastern California. SV and P wave amplitudes were measured from vertical component seismograms of earthquakes that occurred in the Cososouthem Sierra Nevada region from July 1983 to August...
The hydrothermal system at Newberry Volcano, Oregon
E.A. Sammel, S. E. Ingebritsen, Robert H. Mariner
1988, Journal of Geophysical Research Solid Earth (93) 10149-10162
Results of recent geological and geophysical studies at Newberry Volcano have been incorporated into conceptual and numerical models of a magma-based hydrothermal system. Numerical simulations begin with emplacement of a small magma body, the presumed source of silicic eruptions at Newberry that began about 10,000 B.P., into a thermal regime...
Using laser micro mass spectrometry with the LAMMA-1000 instrument for monitoring relative elemental concentrations in vitrinite
J.J. Morelli, D.M. Hercules, P.C. Lyons, C.A. Palmer, J.D. Fletcher
1988, Mikrochimica Acta (96) 105-118
The variation in relative elemental concentrations among a series of coal macerals belonging to the vitrinite maceral group was determined using laser micro mass spectrometry (LAMMS). Variations in Ba, Cr, Ga, Sr, Ti, and V concentrations among the coals were determined using the LAMM A-1000 instrument. LAMMS analysis is not...
Pb, Sr, and Nd isotopic compositions of a suite of Late Archean, igneous rocks, eastern Beartooth Mountains: Implications for crust-mantle evolution
J. L. Wooden, P.A. Mueller
1988, Earth and Planetary Science Letters (87) 59-72
A series of compositionally diverse, Late Archean rocks (2.74–2.79 Ga old) from the eastern Beartooth Mountains, Montana and Wyoming, U.S.A., have the same initial Pb, Sr, and Nd isotopic ratios. Lead and Sr initial ratios are higher and Nd initial ratios...
Seismic imaging of extended crust with emphasis on the western United States
J. McCarthy, G. A. Thompson
1988, Geological Society of America Bulletin (100) 1361-1374
Understanding of the crust has improved dramatically following the application of seismic reflection and refraction techniques to studies of the deep crust. This is particularly true in areas where the last tectonic event was extensional, such as the Basin and Range province of the western United States and much of...
Precursory seismic quiescence: A preliminary assessment of the hypothesis
P.A. Reasenberg, M.V. Matthews
1988, Pure and Applied Geophysics PAGEOPH (126) 373-406
Numerous cases of precursory seismic quiescence have been reported in recent years. Some investigators have interpreted these observations as evidence that seismic quiescence is a somewhat reliable precursor to moderate or large earthquakes. However, because failures of the pattern to predict earthquakes may not, in general, be reported, and because...
