Publications
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Use of strontium isotopes to constrain the timing and mode of dolomitization of upper Cenozoic sediments in a core from San Salvador, Bahamas Use of strontium isotopes to constrain the timing and mode of dolomitization of upper Cenozoic sediments in a core from San Salvador, Bahamas
The 87Sr/86Sr ratios and the activity ratios of 234U/238U and 230Th/238U have been measured in dolomites from a 168-m-deep core taken on the island of San Salvador, Bahamas. These data suggest two periods of dolomitization. The first episode dolomitized Miocene age sediments during the latest Miocene, and the second dolomitized the Pliocene portion of the core and was still active as...
Authors
Peter K. Swart, Joaquin Ruiz, Charles W. Holmes
Dolomitization in a mixing zone of near-seawater composition, Late Pleistocene, northeastern Yucatan Peninsula Dolomitization in a mixing zone of near-seawater composition, Late Pleistocene, northeastern Yucatan Peninsula
Patches of dolomite occur in cores of reefal limestone from the shallow subsurface on the northeastern coast of the Yucatan Peninsula. This limestone accumulated during an interglacial high stand of sea level about 200,000 years ago. Dolomitization was preceded by freshwater diagenesis, including precipitation of sparry calcite cement, stabilization of Mg-calcitic skeletal fragments, and...
Authors
W. C. Ward, Robert B. Halley
High-frequency observations and source parameters of microearthquakes recorded at hard-rock sites High-frequency observations and source parameters of microearthquakes recorded at hard-rock sites
We have estimated the source parameters of 53 microearthquakes recorded in July 1983 which were aftershocks of the Miramichi, New Brunswick, earthquake that occurred on 9 January 1982. These events were recorded by local three-component digital seismographs at 400 sps/component from 2-Hz velocity transducers sited directly on glacially scoured crystalline basement outcrop. Hypocentral...
Authors
Edward Cranswick, Robert Wetmiller, John Boatwright
Preliminary response activities and recommendations of the USGS Landslide Hazard Research Team to the Puerto Rico landslide disaster of October 7, 1985 Preliminary response activities and recommendations of the USGS Landslide Hazard Research Team to the Puerto Rico landslide disaster of October 7, 1985
No abstract available.
Authors
R. H. Campbell, Darrell G. Herd, R.M. Alonso
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, January 1985 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, January 1985
No abstract available.
Authors
John B. Townshend, J.E. Papp, E.A. Sauter, L.Y. Torrence, P.A. Franklin
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1985 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1985
No abstract available.
Authors
John B. Townshend, J.E. Papp, E.A. Sauter, L.Y. Torrence, P.A. Franklin
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1985 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1985
No abstract available.
Authors
John B. Townshend, J.E. Papp, E.A. Sauter, L.Y. Torrence, P.A. Franklin
Geographic variation in ground shaking as a function of changes in near-surface properties and geologic structure near Los Angeles, California Geographic variation in ground shaking as a function of changes in near-surface properties and geologic structure near Los Angeles, California
No abstract available.
Authors
A. M. Rogers, Ladislaus C. Tinsley, Roger D. Borcherdt
Innovative approaches to landslide hazard and risk mapping Innovative approaches to landslide hazard and risk mapping
No abstract available.
Authors
E. E. Brabb
By
Geology, Energy, and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Landslide Hazards Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center
Deformation in the White Mountain seismic gap, California-Nevada, 1972-1982 Deformation in the White Mountain seismic gap, California-Nevada, 1972-1982
A 100×40 km trilateration network extending from Bishop, California, to near Hawthorne, Nevada, crosses the east end of the Long Valley caldera, site of renewed magma inflation in the 1979–1980 interval, and spans most of the White Mountain seismic gap. The network was surveyed in 1972, 1973, 1976, 1979, 1980, and 1982. The 1980 survey may be contaminated by a scale error. In addition...
Authors
James C. Savage, Michael Lisowski
Earthquake swarm in Long Valley caldera, California, January 1983: Evidence for dike inflation Earthquake swarm in Long Valley caldera, California, January 1983: Evidence for dike inflation
The 1982–1983 deformation observed by trilateration and leveling surveys across the Long Valley caldera is apparently related to the 8.5‐km‐long by 8‐km‐deep vertical rupture surface defined by the January 1983 earthquake swarm that occurred in the south moat of the caldera. The observed deformation can be explained as follows. In late 1982, 0.03 km3 of magma was injected into a dike...
Authors
James C. Savage, R.S. Cockerham
Regional deformation near Palmdale, California, 1973-1983 (USA) Regional deformation near Palmdale, California, 1973-1983 (USA)
The Tehachapi trilateration network spans the intersection of the San Andreas and Garlock faults in southern California in the “Big Bend” region of the San Andreas fault. Analysis of data from 1973–1983 shows strain differences between the northwest and southeast regions of the network and slip at depth on both faults. The Palmdale network, spanning the San Andreas fault entirely within...
Authors
N.E. King, James C. Savage