| Abstract: | Radiocarbon-dated volcanic mass-flow deposits on the southeast flank of Mount Spurr in south-central Alaska provide strong evidence for the timing of large-scale destruction of the south flank of the volcano by sector collapse at 4,769^ndash;4,610 yr B.P. The sector collapse created an avalanche caldera and produced an ~1-km3-volume clay-rich debris avalanche that flowed into the glacially scoured Chakachatna River valley, where it transformed into a lahar that extended an unknown distance beyond the debris avalanche. Hydrothermal alteration, an unbuttressed south flank of the volcano, and local structure have been identified as plausible factors contributing to the instability of the edifice. The sector collapse at Mount Spurr is one of the later known large-volume (>1 km,sup>3) flank failures recognized in the Aleutian Arc and one of the few known Alaskan examples of transformation of a debris avalanche into a lahar. |
| Genre: | USGS Numbered Series |
| ProdID: | 80708 |
| Citation Author: | Waythomas, Christopher F. |
| Citation Contributing Office: | USGS Western Mineral Resources |
| Citation Datum: | |
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| Citation Edition: | Version 1.0 |
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| Citation Language: | ENGLISH |
| Citation Larger Work Title: | Studies by the U.S. Geological Survey in Alaska, 2006 |
| Citation LatN: | 0660000 |
| Citation LatS: | 0540000 |
| Citation LonE: | -1450000 |
| Citation LonW: | -1590000 |
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| Citation No Pagination: | |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | Y |
| Citation Phsyical Description: | 15 p. |
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| Citation Publisher: | Geological Survey (U.S.) |
| Citation Series: | Professional Paper |
| Citation Series Code: | PP |
| Citation Series Number: | 1739-C |
| Citation Search Results Text: | Mid-Holocene Sector Collapse at Mount Spurr Volcano, South-Central Alaska; 2007; PP; 1739-C; Studies by the U.S. Geological Survey in Alaska, 2006; Waythomas, Christopher F. |
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| Citation Year: | 2007 |
| Type: | citation/reference |
| Text: | Mid-Holocene Sector Collapse at Mount Spurr Volcano, South-Central Alaska; 2007; PP; 1739-C; Studies by the U.S. Geological Survey in Alaska, 2006; Waythomas, Christopher F. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/pp/pp1739/c/ |
| Date Other: | Wed, 12 Dec 2007 00:00 -0600 |
| Publisher: | Geological Survey (U.S.) |
