Three-dimensional P velocity structure of the crust below Newberry Volcano, Oregon

Journal Article · Sat Sep 10 00:00:00 EDT 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB093iB09p10095· OSTI ID:6969917

Stauber, D A; Green, S M; Iyer, H M

Utilizing teleseismic P residuals, we have detected a column of high P velocity material extending from within 10 km of the surface below the summit of Newberry Volcano, Oregon to midcrustal depths near 25 km. We interpret this column to be the expression of a swarm of predominantly subsolidus gabbroic sills and dikes which were intruded as the volcano was built. The high P velocities observed below the volcano severely limit the size of magma chambers which could presently exist in the crust below Newberry Volcano. Those possible include a few percent of partial melt distributed through large volumes of a mafic intrusion zone in the midcrust; a few smaller, higher melt fraction zones in the midcrust with dimensions less than 6 km and whose aggregate volume is only a few percent of enclosing volumes of 200 km/sup 3/; small magma bodies with dimensions of a few kilometers located within the upper 10 km of the crust; or a mafic, crystal-rich magma of arbitrary dimensions located in the upper few km. The low P velocities detected in the upper 4 km beneath the center of the summit caldera may be partially caused by a magma chamber in the second of these catagories.

• Research Organization: U.S. Geological Survey, Menlo Park, California
• OSTI ID: 6969917
• Journal Information: J. Geophys. Res.; (United States), Vol. 93:B9
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
CASCADE MOUNTAINS
VOLCANISM
VOLCANOES
MAGMA SYSTEMS
CALDERAS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
MAGMATISM
OREGON
SEISMIC P WAVES
FEDERAL REGION X
GEOTHERMAL SYSTEMS
MOUNTAINS
NORTH AMERICA
SEISMIC WAVES
USA
150301* - Geothermal Exploration & Exploration Technology- Geophysical Techniques & Surveys