- Chaos Crags
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Chaos Crags 
Chaos Crags with Chaos Jumbles below.Elevation 8,503 ft (2,592 m) [1] Prominence ~ 580 ft (177 m) Location Location Lassen Volcanic National Park, Shasta County, California, USA Range Cascade Range Coordinates 40°31′27″N 121°31′16″W / 40.52417°N 121.52111°WCoordinates: 40°31′27″N 121°31′16″W / 40.52417°N 121.52111°W Topo map USGS Manzanita Lake Geology Type Lava domes[1] Age of rock Holocene Volcanic arc/belt Cascade Volcanic Arc[2] Last eruption 1,100-1,000 years ago[3] Climbing Easiest route Scrambling Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California, having been formed as five dacite domes 1,100-1,000 years ago.[3] The cluster of domes are located north of Lassen Peak.
From the base of the crags and extending toward the northwest corner of the park is Chaos Jumbles, a cold rock avalanche which undermined Chaos Crags' northwest slope 300 years ago.[4] Riding on a cushion of compressed air (see air-layer lubrication), the rock debris traveled at about 100 miles per hour (160 km/h), flattened the forest before it, and dammed Manzanita Creek, forming Manzanita Lake.
In 1974 the United States Park Service took the advice of the USGS and closed the visitor center and accommodations at Manzanita Lake. The Survey stated that these buildings would be in the way of a rockslide from Chaos Crags if an earthquake or volcanic eruption occurred in the area.
References
- ^ a b "Lassen Volcanic Center - Synonyms and Subfeatures". Global Volcanism Program, Smithsonian Institution. http://www.volcano.si.edu/world/volcano.cfm?vnum=1203-08-&volpage=synsub. Retrieved 2009-01-05.
- ^ "Lassen Volcanic Center". Global Volcanism Program, Smithsonian Institution. http://www.volcano.si.edu/world/volcano.cfm?vnum=1203-08-. Retrieved 2009-01-05.
- ^ a b Wood, Charles A.; Jűrgen Kienle (1993). Volcanoes of North America. Cambridge University Press. pp. 216–219. ISBN 0-512-43811-X.
- ^ Hill, Richard L. (2004-10-01). Volcanoes of the Cascades: Their Rise and Their Risks. Falcon. pp. 86–87. ISBN 978-0762730728. http://books.google.com/books?id=Y2ZXXF_2s8gC&pg=PA86&lpg=PA86&dq=chaos+crags&ct=result#PPA87,M1.
Further reading
- Ann G. Harris, Esther Tuttle, Sherwood D., Tuttle (1997). Geology of National Parks: Fifth Edition. Iowa: Kendall/Hunt Publishing. ISBN 0-7872-5353-7.
- CVO Description - Lassen Peak (Look under Lassen Volcanic National Park - Points of Interest for info on Chaos Crags in that site)
Categories:- Cascade Volcanoes
- Lava domes
- Lassen Volcanic National Park
- Volcanoes of Shasta County, California
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