Publications
Filter Total Items: 3024
Knowledge of the fount and the cause of disaster Knowledge of the fount and the cause of disaster
No abstract available.
Authors
William C. Evans
Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the Cretaceous Logtung W-Mo deposit, Yukon Territory, Canada Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the Cretaceous Logtung W-Mo deposit, Yukon Territory, Canada
Comb-layered quartz is a type of unidirectional solidification texture found at the roofs of shallow silicic intrusions that are often associated spatially with Mo and W mineralisation. The texture consists of multiple layers of euhedral, prismatic quartz crystals (Type I) that have grown on subplanar aplite substrates. The layers are separated by porphyritic aplite containing equant...
Authors
Jacob B. Lowenstern, W. David Sinclair
Earthquakes and carbon dioxide beneath Mammoth Mountain, California Earthquakes and carbon dioxide beneath Mammoth Mountain, California
No abstract available.
Authors
David P. Hill
Photographs of the 1989-90 eruptions of Redoubt Volcano, Alaska Photographs of the 1989-90 eruptions of Redoubt Volcano, Alaska
No abstract available.
Authors
A.L. Roach, Christina A. Neal, R. G. McGimsey
Hydrologic data for Long Valley Caldera, Mono County, California, 1987-93 Hydrologic data for Long Valley Caldera, Mono County, California, 1987-93
Hydrologic data were collected during 1987-93 as part of the U.S. Geological Survey's long-term Volcanic Hazards Monitoring Program of the Long Valley Caldera, Mono County, California. The data are presented in graphs or tables. Data collected for the Long Valley Hydrologic Advisory Committee monitoring program also are presented. Hydrologic data collected include continuous record of...
Authors
J. F. Howle, C. D. Farrar
The most recent eruptions of Hualalai Volcano, Hawaii; an annotated bibliography The most recent eruptions of Hualalai Volcano, Hawaii; an annotated bibliography
No abstract available.
Authors
J. P. Kauahikaua, Bobby Camara
Recurrent eruption and subsidence at the Platoro caldera complex, southeastern San Juan volcanic field, Colorado: New tales from old tuffs Recurrent eruption and subsidence at the Platoro caldera complex, southeastern San Juan volcanic field, Colorado: New tales from old tuffs
Reinterpretation of a voluminous regional ash-flow sheet (Masonic Park Tuff) as two separate tuff sheets of similar phenocryst-rich dacite erupted from separate source calderas has important implications for evolution of the multicyclic Platoro caldera complex and for caldera-forming processes generally. Masonic Park Tuff in central parts of the San Juan field, including the type area...
Authors
P. W. Lipman, M.A. Dungan, L.L. Brown, A. Deino
Volatile emissions from the crater and flank of Oldoinyo Lengai volcano, Tanzania Volatile emissions from the crater and flank of Oldoinyo Lengai volcano, Tanzania
As a comparison to airborne infrared (IR) flux measurements, ground-based sampling of fumarole and soil gases was used to characterize the quiescent degassing of CO2 from Oldoinyo Lengai volcano. Aerial and ground-based measurements are in good agreement: ∼75% of the aerially measured CO2 flux at Lengai (0.05–0.06 × 1012 mol yr−1 or 6000–7200 tonnes CO2 d−1) can be attributed to seven...
Authors
K.W. Koepenick, S.L. Brantley, J. M. Thompson, G.L. Rowe, A.A. Nyblade, C. Moshy
Observed discrepancy between geodolite and GPS distance measurements Observed discrepancy between geodolite and GPS distance measurements
Comparison of contemporaneous measurements of 84 distances in the range of 10 to 50 km by both Global Positioning System (GPS) and Geodolite (an electro-optical distance-measuring instrument) indicates that the Geodolite measurements are systematically longer by 0.283 ± 0.100 parts per million of the measured distance. Quoted uncertainty is 1 standard deviation. This amounts to 11.3 ± 4...
Authors
J.C. Savage, M. Lisowski, W.H. Prescott
Differentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas Differentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas
New and detailed petrographic observations, mineral compositional data, and whole-rock vs glass compositional trends document magma mixing in lavas erupted from Kilauea's lower east rift zone in 1960. Evidence includes the occurrence of heterogeneous phenocryst assemblages, including resorbed and reversely zoned minerals in the lavas inferred to be hybrids. Calculations suggest that this...
Authors
T. L. Wright, Rosalind Tuthill Helz
Long-term geochemical surveillance of fumaroles at Showa-Shinzan dome, Usu volcano, Japan Long-term geochemical surveillance of fumaroles at Showa-Shinzan dome, Usu volcano, Japan
This study investigates 31 years of fumarole gas and condensate (trace elements) data from Showa-Shinzan, a dacitic dome-cryptodome complex that formed during the 1943-1945 eruption of Usu volcano. Forty-two gas samples were collected from the highest-temperature fumarole, named A-1, from 1954 (800??C) to 1985 (336??C), and from lower-temperature vents. Condensates were collected...
Authors
R.B. Symonds, Y. Mizutani, Paul H. Briggs
Mauna Loa lava accumulation rates at the Hilo drill site: Formation of lava deltas during a period of declining overall volcanic growth Mauna Loa lava accumulation rates at the Hilo drill site: Formation of lava deltas during a period of declining overall volcanic growth
Accumulation rates for lava flows erupted from Mauna Loa, as sampled in the uppermost 280 m of the Hilo drill hole, vary widely for short time intervals (several thousand years), but overall are broadly similar to those documented elsewhere on this volcano since 100 ka. Thickness variations and accumulation rates for Mauna Loa lavas at the Hilo drill site have been strongly affected by...
Authors
P. W. Lipman, J.G. Moore