Publications
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Origin of phenocrysts and compositional diversity in pre-Mazama rhyodacite lavas, Crater Lake, Oregon Origin of phenocrysts and compositional diversity in pre-Mazama rhyodacite lavas, Crater Lake, Oregon
Phenocrysts in porphyritic volcanic rocks may originate in a variety of ways in addition to nucleation and growth in the matrix in which they are found. Porphyritic rhyodacite lavas that underlie the eastern half of Mount Mazama, the High Cascade andesite/dacite volcano that contains Crater Lake caldera, contain evidence that bears on the general problem of phenocryst origin. Phenocrysts...
Authors
S. Nakada, C. R. Bacon, A.E. Gartner
Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii
In 1990, the State of Hawaii proposed the Hawaii Geothermal Project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. This report uses data from 31 wells and 8 springs to describe the properties of the ground-water system in and adjacent to the East Rift Zone. Potential effects of this project on ground-water...
Authors
M.L. Sorey, E.M. Colvard
Whole-rock analyses of core samples from the 1967, 1975, 1979 and 1981 drillings of Kilauea Iki lava lake, Hawaii Whole-rock analyses of core samples from the 1967, 1975, 1979 and 1981 drillings of Kilauea Iki lava lake, Hawaii
No abstract available
Authors
Rosalind Tuthill Helz, H.K. Kirschenbaum, J.W. Marinenko, Rachel Qian
Stream-channel changes in response to volcanic detritus under natural and augmented discharge, South Coldwater Creek, Washington Stream-channel changes in response to volcanic detritus under natural and augmented discharge, South Coldwater Creek, Washington
No abstract available.
Authors
D. F. Meyer
Multiple isotopic components in Quaternary volcanic rocks of the Cascade Arc near Crater lake, Oregon Multiple isotopic components in Quaternary volcanic rocks of the Cascade Arc near Crater lake, Oregon
Quaternary lavas and pyroclastic rocks of Mount Mazama, Crater lake caldera, and the surrounding area have variable Sr, Nd, and Pb isotopic compositions. High-alumina olivine tholeiites have 87Ar/86Ar ratios of 0.70346-0.70364; basaltic andesite, 0.70349-0.70372; shoshonitic basaltic andesite, 0.70374-0.70388; and andesite, 0.70324-0.70383. Dacites of Mount Mazama have 87Sr/ 86Sr ratios...
Authors
C. R. Bacon, S.H. Gunn, M. A. Lanphere, J. L. Wooden
Dissolved volatile concentrations in an ore-forming magma Dissolved volatile concentrations in an ore-forming magma
Infrared spectroscopic measurements of glass inclusions within quartz phenocrysts from the Plinian fallout of the 22 Ma tuff of Pine Grove show that the trapped silicate melt contained high concentrations of H2O and CO2. Intrusive porphyries from the Pine Grove system are nearly identical in age, composition, and mineralogy to the tephra, and some contain high-grade Mo mineralization...
Authors
J. B. Lowenstern
Giant Hawaiian landslides Giant Hawaiian landslides
Sixty-eight landslides more than 20 km long are present along a 2200 km segment of the Hawaiian Ridge from near Midway to Hawaii. Some of the landslides exceed 200 km in length and 5000 km3 in volume, ranking them among the largest on Earth. Most of these giant landslides were discovered during a mapping program of the U.S. Hawaiian Exclusive Economic zone from 1986 to 1991 utilizing the...
Authors
J.G. Moore, W. R. Normark, R. T. Holcomb
Tapping the Earth's natural heat Tapping the Earth's natural heat
T he Earth is a bountiful source of heat. It continuously produces heat at depth, primarily by the decay of naturally radioactive chemical elements (principally uranium, thorium, and potassium) that occur in small amounts in all rocks. This deep heat then rises toward the cooler surface, where scientists can measure the rate of its escape through the Earth's crust. The annual heat loss...
Authors
Wendell A. Duffield, J.H. Sass, M.L. Sorey
Volcanic gas emissions and their impact on ambient air character at Kilauea Volcano, Hawaii Volcanic gas emissions and their impact on ambient air character at Kilauea Volcano, Hawaii
Currently, gas emissions from Kilauea occur from the summit caldera, along the middle East Rift Zone (ERZ), and where lava enters the ocean. We estimate that the current ERZ eruption of Kilauea releases between 400 metric tonnes of SO2 per day, during eruptive pauses, to as much as 1850 metric tonnes per day during actively erupting periods, along with lesser amounts of other chemically...
Authors
A. J. Sutton, T. Elias, R. Navarrete
Russian volcanic eruption disrupts north pacific air traffic: Alaska Volcano Observatory fact sheet Russian volcanic eruption disrupts north pacific air traffic: Alaska Volcano Observatory fact sheet
No abstract available.
Authors
Thomas P. Miller, Vladimir Yu. Kirianov, H. Lee Kelley
Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska Rare earth element contents and multiple mantle sources of the transform-related Mount Edgecumbe basalts, southeastern Alaska
Pleistocene basalt of the Mount Edgecumbe volcanic field (MEF) is subdivided into a plagioclase type and an olivine type. Olivine basalt crops out farther inboard from the nearby Fairweather transform than plagioclase basalt. Th/La ratios of plagioclase basalt are similar to those of mid-ocean-ridge basalt (MORB), whereas those of olivine basalt are of continental affinity. The olivine...
Authors
J.R. Riehle, J. R. Budahn, M. A. Lanphere, D. A. Brew