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GEOREF RECORD

Catastrophic debris avalanche from ancestral Mount Shasta Volcano, California

D. R. Crandell, C. D. Miller, H. X. Glicken, R. L. Christiansen and C. G. Newhall
Catastrophic debris avalanche from ancestral Mount Shasta Volcano, California
Geology (Boulder) (March 1984) 12 (3): 143-146

Abstract

A debris-avalanche deposit extends 43 km northwestward from the base of Mount Shasta across the floor of Shasta Valley, where it covers an area of at least 450 km (super 2) . The surface of the deposit is dotted with hundreds of mounds, hills, and ridges, all formed of blocks of pyroxene andesite and unconsolidated volcaniclastic deposits derived from an ancestral Mount Shasta. Individual hills are separated by flat-topped laharlike deposits that also form the matrix of the debris avalanche and slope northwestward about 5 m/km. Radiometric ages of rocks in the deposit and of a postavalanche basalt flow indicate that the avalanche occurred between about 300,000 and 360,000 yr ago. An inferred average thickness of the deposit, plus a computed volume of about 4 km (super 3) for the hills and ridges, indicate an estimated volume of about 26 km (super 3) , making it the largest known Quaternary landslide on Earth.--Modified journal abstract.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 12
Serial Issue: 3
Title: Catastrophic debris avalanche from ancestral Mount Shasta Volcano, California
Affiliation: U. S. Geol. Surv., Denver, CO, United States
Pages: 143-146
Published: 198403
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 9
Accession Number: 1984-029703
Categories: Geomorphology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sketch map
N41°15'00" - N41°45'00", W122°45'00" - W122°00'00"
Secondary Affiliation: Univ. Calif., USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 1984
Program Name: USGSOPNon-USGS publications with USGS authors
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