Teleseismically recorded seismicity before and after the May 7, 1986, Andreanof Islands, Alaska, earthquake
E.R. Engdahl, S. Billington, C. Kisslinger
1989, Journal of Geophysical Research Solid Earth (94) 15481-15498
The May 7, 1986, Andreanof Islands earthquake (Mw 8.0) is the largest event to have occurred in that section of the Aleutian arc since the March 9, 1957, Aleutian Islands earthquake (Mw 8.6). Teleseismically well-recorded earthquakes in the region of the 1986 earthquake are relocated with a plate model and with careful...
Geochemistry of intrusive rocks associated with the Latir volcanic field, New Mexico, and contrasts between evolution of plutonic and volcanic rocks
C.M. Johnson, G.K. Czamanske, P. W. Lipman
1989, Contributions to Mineralogy and Petrology (103) 90-109
Plutonic rocks associated with the Latir volcanic field comprise three groups: 1) ???25 Ma high-level resurgent plutons composed of monzogranite and silicic metaluminous and peralkaline granite, 2) 23-25 Ma syenogranite, and alkali-feldspar granite intrusions emplaced along the southern caldera margin, and 3) 19-23 Ma granodiorite and granite plutons emplaced south...
Urban watershed data for the United States
Janice M. Fulford
1989, Conference Paper
The contents of an urban watershed data base compiled for a national urban flood-frequency study by the U.S. Geological Survey are described. The data base includes information for 269 urbanized watersheds in 56 metropolitan areas in 31 states in the continental United States and Hawaii....
Spectral characteristics of chlorites and Mg‐serpentines using high‐resolution reflectance spectroscopy
T. V. V. King, Roger N. Clark
1989, Journal of Geophysical Research: Solid Earth (94) 13997-14008
The present laboratory study using high‐resolution reflectance spectroscopy (0.25–2.7 μm) focuses on two primary phyllosilicate groups, serpentines and chlorites. The results show that it is possible to spectrally distinguish between isochemical end‐members of the Mg‐rich serpentine group (chrysotile, antigorite, and lizardite) and to recognize spectral variations in chlorites as a...
History of the Federal Interagency Sedimentation Project
John V. Skinner
1989, Conference Paper
Since 1939, the date of the Project's inception, the team has operated under the direction of two lead agencies - the U.S. Geological Survey and U.S. Army Corps of Engineers. The supporting agencies are the Agricultural Research Service, Bureau of Reclamation, U.S. Forest Service, Bureau of Land Management, Federal Highway...
Geologic framework of the offshore region adjacent to Delaware
R.N. Benson, J.H. Roberts
1989, Marine Geology (90) 103-111
Several multichannel, common depth point (CDP) seismic reflection profiles concentrated in the area of the entrance to Delaware Bay provide a tie between the known onshore geology of the Coastal Plain of Delaware and the offshore geology of the Baltimore Canyon...
State and local response to damaging land subsidence in United States urban areas
T.L. Holzer
1989, Engineering Geology (27) 449-466
Land subsidence caused by man-induced depressuring of underground reservoirs has occurred in at least nine urban areas in the United States. Significant efforts to control it have been made in three areas: Long Beach, California; Houston-Galveston, Texas; and Santa Clara Valley, California. In these areas coastal flooding and its control...
Compaction of basin sediments: Modeling based on time-temperature history
J. W. Schmoker, D. L. Gautier
1989, Journal of Geophysical Research Solid Earth (94) 7379-7386
Porosity decrease of sandstones, carbonates, and shales during burial is modeled here in terms of time-temperature exposure rather than in terms of depth. Loss of porosity (ϕ) in the subsurface is represented by a power function, ϕ = A(M)B, where A and B are constants and M is a measure of integrated time-temperature history. Regression lines of...
Evidence for an Early Archean component in the Middle to Late Archean gneisses of the Wind River Range, west-central Wyoming: conventional and ion microprobe U-Pb data
J. N. Aleinikoff, I.S. Williams, W. Compston, J. S. Stuckless, R. G. Worl
1989, Contributions to Mineralogy and Petrology (101) 198-206
Gneissic rocks that are basement to the Late Archean granites comprising much of the Wind River Range, west-central Wyoming, have been dated by the zircon U-Pb method using both conventional and ion microprobe techniques. A foliated hornblende granite gneiss member from the southern border of the Bridger batholith is 2670??13...
Geochemistry of placer gold, Koyukuk-Chandalar mining district, Alaska
E. L. Mosier, J. B. Cathrall, J.C. Antweiler, R. B. Tripp
1989, Journal of Geochemical Exploration (31) 97-115
The Koyukuk-Chandalar mining district of the Brooks Range mineral belt in north-central Alaska contains numerous placer gold deposits but few known lode gold sources. Gold grains, collected from 46 placer localities and 6 lode gold sites in the district, were analyzed for Ag and 37 trace elements utilizing direct current-arc...
Acadian metamorphism associated with the Lexington batholith, Bingham, Maine
Robert P. Dickerson, M. J. Holdaway
1989, American Journal of Science (289) 945-974
No abstract available....
Age distribution of Serra Geral (Paraná) flood basalts, southern Brazil
R.V. Fodor, E.H. McKee, A. Roisenberg
1989, Journal of South American Earth Sciences (2) 343-349
We evaluated 193 K-Ar ages (10 newly determined) of basaltic and differentiated rocks of the Serra Geral (Paraná) flood-basalt province for indications of magmatism occurring systematically with progressive rifting and complete separation ( ≈130-105 Ma) of South America from Africa. The K-Ar ages represent basalt emplacement between 35° and 19°S...
Improved dating of the Pliocene of the eastern South Atlantic using graphic correlation: implications for paleobiogeography and paleoceanography
H.J. Dowsett
1989, Micropaleontology (35) 279-292
Graphic correlation of foraminifer and nannofossil events establishes a high resolution chronology for the Pliocene at Deep Sea Drilling Project Site 532. Coarsely sampled magnetic inclination data are reinterpreted to indicate a complete Pliocene section. The age model suggests mean accumulation rates of 9.5 cm 10-3 yr for the first...
The Uranium-trend dating method: Principles and application for southern California marine terrace deposits
D.R. Muhs, J.N. Rosholt, C. A. Bush
1989, Quaternary International (1) 19-34
Uranium-trend dating is an open-system method for age estimation of Quaternary sediments, using disequilibrium in the 238U234U230Th decay series. The technique has been applied to alluvium, colluvium, loess, till, and marine sediments. In this study we tested the U-trend dating method on calcareous marine terrace deposits from the Palos Verdes...
Solid-state 13C NMR studies of a large fossil gymnosperm from the Yallourn Open Cut, Latrobe Valley, Australia
Anne L. Bates, Patrick G. Hatcher
1989, Organic Geochemistry (14) 609-617
A series of samples taken from the cross section of a 3-m-diameter fossilized gymnospermous log (Araucariaceae) in the Yallourn Seam of the Australian brown coals was examined by solid state 13C nuclear magnetic resonance to delineate chemical changes related to the combined processes of peatification and coalification. The results show that...
Seismic reflection characteristics of glacial and glacimarine sediment in the Gulf of Alaska and adjacent fjords
P.R. Carlson
1989, Marine Geology (85) 391-416
Glaciation together with tectonism have been dominant factors affecting sedimentation in the Gulf of Alaska area from at least the late Miocene throughout the Quaternary. The effects of tectonism are apparent in high mountains that border the gulf, raised terraces of...
Microearthquake spectra from the Anza, California, seismic network: Site response and source scaling
Arthur D. Frankel, Leif Wennerberg
1989, Bulletin of the Seismological Society of America (79) 581-609
We analyzed spectra of local microearthquakes recorded by the Anza, California, seismic network to isolate the effects of site response and to investigate the scaling of source parameters for small earthquakes. Spectra of microearthquakes (M < 2; Mo < 1019 dyne-cm) at Anza have shapes characteristic of the receiver sites...
Early Cretaceous vein-related garnet granulite in Fiordland, southwest New Zealand: a case for infiltration of mantle-derived CO2-rich fluids
J.Y. Bradshaw
1989, Journal of Geology (97) 697-717
Regionally extensive two-pyroxene granulite facies orthogneisses of Early Cretaceous age in Fiordland, southwest New Zealand, are criss-crossed by garnet-bearing feldspathic veins (and dikes) having associated marginal reaction zones of garnet granulite. The two-pyroxene granulites resulted from fluid-absent meta-morphism of a suite of...
The dependence of peak horizontal acceleration on magnitude, distance, and site effects for small-magnitude earthquakes in California and eastern North America
K.W. Campbell
1989, Bulletin of the Seismological Society of America (79) 1311-1346
One-hundred and ninety free-field accelerograms recorded on deep soil (> 10 m deep) were used to study the near-source scaling characteristics of peak horizontal acceleration for 91 earthquakes (2.5 ≦ ML ≦ 5.0) located primarily in California. Of the six attenuation relationships developed in this study, the one considered most...
Plans for national flood frequency by microcomputer
M.E. Jennings, E.N. Cookmeyer
1989, Conference Paper
Work is underway on a planned microcomputer program that will include about 1500 prediction equations for 214 flood regions of the United States and Puerto Rico. The program will include calculation routines for rural and urban flood frequency and hydrograph characteristics and will have links to a detention-pond routing model....
Dune migration in a steep, coarse-bedded stream
Randy L. Dinehart
1989, Water Resources Research (25) 911-923
During 1986 and 1987, migrating bed forms composed of coarse sand and fine gravel (d50=1.8 to 9.1 mm) were documented in the North Fork Toutle River at Kid Valley, Washington, at flow velocities ranging from 1.6 to 3.4 m s−1 and depths of 0.8 to 2.2 m. The bed forms (predominantly...
Porosity development in coastal carbonate aquifers
W. E. Sanford, Leonard F. Konikow
1989, Geology (17) 249-252
Geochemical mixing theory suggests that the mixing of seawater and calcite-saturated fresh ground water can result in a solution that is undersaturated with respect to calcite. Previous studies of the mixing of such waters in carbonate rocks along certain coastlines have indicated that...
A hybrid fast Hankel transform algorithm for electromagnetic modeling
W.L. Anderson
1989, Geophysics (54) 263-266
A hybrid fast Hankel transform algorithm has been developed that uses several complementary features of two existing algorithms: Anderson's digital filtering or fast Hankel transform (FHT) algorithm and Chave's quadrature and continued fraction algorithm. A hybrid FHT subprogram (called HYBFHT) written in standard Fortran-77 provides a simple user interface to...
Oxygen-isotope composition of ground water and secondary minerals in Columbia Plateau basalts: Implications for the paleohydrology of the Pasco Basin
P.P. Hearn Jr., W.C. Steinkampf, D. G. Horton, G.C. Solomon, L. D. White, J.R. Evans
1989, Geology (17) 606-610
Concentrations of 18O and deuterium in ground waters beneath the Hanford Reservation, Washington State, suggest that the meteoric waters recharging the basalt aquifers have been progressively depleted in these isotopes since at least Pleistocene time. This conclusion is supported by oxygen-isotope analyses of low-temperature...
A direct correlation among indoor Rn, soil gas Rn and geology in the Reading Prong near Boyertown, Pennsylvania
G.M. Reimer, L.C.S. Gundersen
1989, Health Physics (57) 155-160
We feel that this study suggests a relationship among geology, soil gas Rn and the potential for indoor Rn accumulation in this portion of the Reading Prong. There are deviations from a perfect correlation but these are related to inhomogeneities in the geologic environment and perhaps variations in construction techniques...
