Death Valley bright spot: a midcrustal magma body in the southern Great Basin, California

Journal Article · Wed Jan 01 04:00:00 EST 1986 · Geology; (United States)

DOI:https://doi.org/10.1130/0091-7613(1986)14<64:DVBSAM>2.0.CO;2· OSTI ID:5549441

de Voogd, B; Serpa, L; Brown, L; Hauser, E; Kaufman, S; Oliver, J; Troxel, B W; Willemin, J; Wright, L A

A previously unrecognized midcrustal magma body may have been detected by COCORP deep seismic reflection profiles in the Death Valley region of the southern Great Basin. High-amplitude, relatively broad-band reflections at 6 s (15 km) are attributed to partially molten material within a subhorizontal intrusion. This bright spot extends laterally at least 15 km beneath central Death Valley. A moderately dipping normal fault can be traced from the inferred magma chamber upward to a 690,000-yr-old basaltic cinder cone. The fault zone is inferred to have been a magma conduit during the formation of the cinder cone. Vertical variations in crustal reflection character suggest that the Death Valley magma body may have been emplaced along a zone of decoupling that separates a faulted brittle upper crust from a more ductile and/or intruded lower crust. The Death Valley bright spot is similar to reflections recorded by COCORP in 1977 in the Rio Grande rift, where both geophysical and geodetic evidence support the inference of a tabular magma chamber at 20-km depth.

• Research Organization: Cornell Univ., Ithaca, NY
• OSTI ID: 5549441
• Journal Information: Geology; (United States), Journal Name: Geology; (United States) Vol. 14:1; ISSN GLGYB
• Country of Publication: United States
• Language: English

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580201* -- Geophysics-- Seismology &amp; Tectonics-- (1980-1989)
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DIMENSIONS
FEDERAL REGION IX
FEDERAL REGION VI
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