Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2486
Entrenchment and widening of the upper San Pedro River, Arizona Entrenchment and widening of the upper San Pedro River, Arizona
The San Pedro River of southeast Arizona is a north-flowing tributary of the Gila River. The area of the drainage basin upstream of the 40-km-long study reach is about 3,200 km2. This study traces the historical evolution of the San Pedro River channel—specifically, the deepening, widening, and sediment deposition that have occurred since 1900—and it aims to evaluate the causes of...
Authors
Richard Hereford
Klamath Falls earthquakes, September 20, 1993 — Including the strongest quake ever measured in Oregon Klamath Falls earthquakes, September 20, 1993 — Including the strongest quake ever measured in Oregon
Earthquakes struck the Klamath Falls area on Monday night, September 20, 1993, resulting in two deaths and extensive damage. The quakes were felt as far away as Coos Bay to the west, Eugene to the north, Lakeview to the east, and Chico, California, to the south. A foreshock recorded at 8:16 p.m. had a Richter magnitude of 3.9. The first of two main shocks, measuring 5.9 on the Richter...
Authors
T. J. Wiley, David R. Sherrod, David K. Keefer, Anthony Qamar, Robert L. Schuster, James W. Dewey, Matthew A. Mabey, Gerald L. Black, Ray E. Wells
Mid‐Cretaceous extensional tectonics of the Yukon‐Tanana Terrane, Trans‐Alaska Crustal Transect (TACT), east‐central Alaska Mid‐Cretaceous extensional tectonics of the Yukon‐Tanana Terrane, Trans‐Alaska Crustal Transect (TACT), east‐central Alaska
Mid‐Cretaceous crustal extension played a fundamental role in the structural evolution of the Yukon‐Tanana terrane (YTT) in the northern Cordilleran interior. In the central portion of the YTT northwest of Delta Junction, Alaska, a mylonitic shear zone juxtaposes greenschist facies rocks in the upper plate against middle to upper amphibolite facies metamorphic rocks in the lower plate, a
Authors
Terry L. Pavlis, V.B. Sisson, Helen L. Foster, Warren J. Nokleberg, George Plafker
Northward displacements of forearc slivers in the Coast Ranges of California and Southwest Oregon during the late Mesozoic and early Cenozoic Northward displacements of forearc slivers in the Coast Ranges of California and Southwest Oregon during the late Mesozoic and early Cenozoic
North American-Farallon-Kula plate motion data, combined with estimated strikeslip displacements obtained from the obliquity of convergence along active circumPacific subduction zones, can be used to estimate the amount of strike-slip displacement along the forearc region of western North America. This evidence suggests a minumum of 500 km and maximum of 1600 km displacement with respect...
Authors
A. S. Jayko, M.C. Blake
Broad trends in geomagnetic paleointensity on Hawaii during Holocene time Broad trends in geomagnetic paleointensity on Hawaii during Holocene time
Paleointensity determinations have been obtained from 22 basaltic lava flows on the island of Hawaii using the Thelliers' method. Radiocarbon dating indicates that these flows erupted at intervals ranging from about 200 to 1000 years, and results of the experiments provide an estimate of broad trends in geomagnetic paleointensity during Holocene time in the vicinity of Hawaii. Most of...
Authors
Edward A. Mankinen, Duane E. Champion
By
Natural radionuclides Natural radionuclides
No abstract available.
Authors
D. Kirk Nordstrom, Richard B. Wanty
Analytical results for As species and related elements in interstitial porewater and sediment from the Maurice River and Union Lake in Vineland, New Jersey Analytical results for As species and related elements in interstitial porewater and sediment from the Maurice River and Union Lake in Vineland, New Jersey
Union Lake, the Maurice River, and the Blackwater Branch , a tributary of the Maurice River, all parts of a small watershed near Vineland, New Jersey, are contaminated by arsenic (As) from a local chemical factory (fig. l)(Faust and others, 1987). An indepth study to be used for the design of the remedial action at the Vineland Chemical Co. Superfund site was initiated by the U.S...
Authors
W. H. Ficklin, Laurie S. Balistrieri, P. L. Hageman, C. S. Papp, D.L. Fey, Matthew Westgate
Development of 3-D lithostratigraphic and confidence models at Yucca Mountain, Nevada Development of 3-D lithostratigraphic and confidence models at Yucca Mountain, Nevada
Computerized three-dimensional geologic models of potential high-level nuclear waste repositories such as Yucca Moutain, Nevada, are important for visualizing the complex interplay of (1) thickness and facies variations in lithostratigraphic units and (2) the disruption of these units by faults. The concept of a 'model of confidence' in the lithostratigraphic model is introduced to show...
Authors
D.C. Buesch, J.E. Nelson, R. P. Dickerson, R.W. Spengler
Spatial and temporal analysis of precious-metal deposit models for a mineral resource assessment of Nevada Spatial and temporal analysis of precious-metal deposit models for a mineral resource assessment of Nevada
No abstract available.
Authors
Steve Ludington, D. P. Cox, M.G. Sherlock, Donald A. Singer, Byron R. Berger, Joseph V. Tingley
Development of grade and tonnage models for different deposit types Development of grade and tonnage models for different deposit types
No abstract available.
Authors
Donald A. Singer
The nature of mineral deposits and the development and use of deposit models The nature of mineral deposits and the development and use of deposit models
No abstract available.
Authors
Donald A. Singer, Dennis P. Cox