Publications
Filter Total Items: 3068
The eruption of Redoubt Volcano, Alaska, December 14, 1989-August 31, 1990 The eruption of Redoubt Volcano, Alaska, December 14, 1989-August 31, 1990
No abstract available.
Authors
Thomas J. Casadevall, Bernard A. Chouet, John N. Davies, Steven A. Estes, Cynthia A. Gardner, Richard P. Hoblitt, John C. Lahr, Richard G. Lahusen, Jon J. Major, Robert G. McGimsey, Thomas P. Miller, Thomas L. Murray, Christina A. Neal, Christopher J. Nye, Robert A. Page, Thomas C. Pierson, John Power, Christopher D. Stephens, Richard B. Waitt
Groundwater flow-field in infinite slopes Groundwater flow-field in infinite slopes
No abstract available.
Authors
R.M. Iverson
Monitoring the hydrologic system for potential effects of geothermal and ground-water development in the Long Valley caldera, Mono County, California, U.S.A. Monitoring the hydrologic system for potential effects of geothermal and ground-water development in the Long Valley caldera, Mono County, California, U.S.A.
In the early 1980's, renewed interest in the geothermal potential of the Long Valley caldera, California, highlighted the need to balance the benefits of energy development with the established recreational activities of the area. The Long Valley Hydrologic Advisory Committee, formed in 1987, instituted a monitoring program to collect data during the early stages of resource utilization...
Authors
C. D. Farrar, D. L. Lyster
Rhyolitic calderas of the Yukon-Tanana Terrane, east central Alaska: volcanic remnants of a mid-Cretaceous magmatic arc Rhyolitic calderas of the Yukon-Tanana Terrane, east central Alaska: volcanic remnants of a mid-Cretaceous magmatic arc
Four large but poorly exposed rhyolitic calderas are present in the Yukon-Tanana terrane (YTT) in east central Alaska. At least two are mid-Cretaceous in age (~93 Ma). Similar volcanic rocks, the South Fork Volcanics, occur northeast of the Tintina fault in Yukon Territory. Evidence for the calderas consists of thick deposits of devitrified crystal- and lithic-rich densely welded tuff...
Authors
C. R. Bacon, H.L. Foster, James G. Smith
Mount Mazama and Crater Lake caldera, Oregon Mount Mazama and Crater Lake caldera, Oregon
No abstract available.
Authors
Charles R. Bacon
IGC field trip T312: South cascades arc volcanism, California and southern Oregon IGC field trip T312: South cascades arc volcanism, California and southern Oregon
No abstract available.
Authors
L.J. Patrick Muffler, Charles R. Bacon, Robert L. Christiansen, Michael A. Clynne, Julie M. Donnelly-Nolan, Cheryl Miller, David R. Sherrod, J.C. Smith
Measures of little gravity Measures of little gravity
No abstract available.
Authors
Robert I. Tilling
Direct evidence for the origin of low-18O silicic magmas: quenched samples of a magma chamber's partially-fused granitoid walls, Crater Lake, Oregon Direct evidence for the origin of low-18O silicic magmas: quenched samples of a magma chamber's partially-fused granitoid walls, Crater Lake, Oregon
Partially fused granitoid blocks were ejected in the climactic eruption of Mount Mazama, which was accompanied by collapse of Crater Lake caldera. Quartz, plagioclase, and glass in the granitoids have much lower δ18O values (−3.4 to +4.9‰) than any fresh lavas of Mount Mazama and the surrounding region (+5.8 to +7.0‰). Oxygen isotope fractionation between phases in granitoids is...
Authors
Charles R. Bacon, Lanford H. Adami, Marvin A. Lanphere
Dynamic pore-pressure fluctuations in rapidly shearing granular materials Dynamic pore-pressure fluctuations in rapidly shearing granular materials
Results from two types of experiments show that intergranular pore pressures fluctuated dynamically during rapid, steady shear deformation of water-saturated granular materials. During some fluctuations, the pore water locally supported all normal and shear stresses, while grain-contact stresses transiently fell to zero. Fluctuations also propagated outward from the shear zone; this...
Authors
Richard M. Iverson, Richard G. Lahusen
Crystallization of accessory phases in magmas by local saturation adjacent to phenocrysts Crystallization of accessory phases in magmas by local saturation adjacent to phenocrysts
Accessory minerals commonly occur attached to or included in the major crystalline phases of felsic and some intermediate igneous rocks. Apatite is particularly common as inclusions, but Fe-Ti oxides, pyrrhotite, zircon, monazite, chevkinite and xenotime are also known from silicic rocks. Accessories may nucleate near the host crystal/ liquid interface as a result of local saturation...
Authors
C. R. Bacon