Catastrophic debris avalanche from ancestral Mount Shasta volcano, California

Research Article| March 01, 1984 Catastrophic debris avalanche from ancestral Mount Shasta volcano, California D. R. Crandell; D. R. Crandell 1U.S. Geological Survey, Box 25046, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar C. D. Miller; C. D. Miller 1U.S. Geological Survey, Box 25046, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar H. X. Glicken; H. X. Glicken 2Department of Geological Sciences, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar R. L. Christiansen; R. L. Christiansen 3U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar C. G. Newhall C. G. Newhall 4USGS Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar Geology (1984) 12 (3): 143–146. https://doi.org/10.1130/0091-7613(1984)122.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation D. R. Crandell, C. D. Miller, H. X. Glicken, R. L. Christiansen, C. G. Newhall; Catastrophic debris avalanche from ancestral Mount Shasta volcano, California. Geology 1984;; 12 (3): 143–146. doi: https://doi.org/10.1130/0091-7613(1984)122.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A debris-avalanche deposit extends 43 km northwestward from the base of Mount Shasta across the floor of Shasta Valley, California, where it covers an area of at least 450 km2. 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 km3 for the hills and ridges, indicate an estimated volume of about 26 km3, making it the largest known Quaternary landslide on Earth. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.