Capital 1090000 yBP
Start: 1090000 yBP [1]
Stop: 1020000 yBP [1]
Event Type: Effusive
Description: From Richter and others (1990): "Capital Mountain is the erosional remnant of a relatively small andesitic shield volcano with a roughly circular, 4-km-wide summit caldera, filled with more than 900 m of andesite flows (Richter and others 1989). Near the center of the caldera, a prominent volcanic plug is the locus of a postcaldera, predominantly andesitic, radial dike swarm that is unique in the WVF. A rhyolite dike that extends more than 10 km across the shield and caldera, probably represents the last magmatic activity of the volcano. K-Ar ages of 1.02- 1.09 Ma for the andesite shield lavas (nos. 48, 49), andesite dike (no. 50), and rhyolite dike (no. 51) suggest that Capital volcano was active during a relatively short time period as compared to other western WVF volcanoes."
References Cited
[1] Age and progression of volcanism, Wrangell volcanic field, Alaska, 1990
Richter, D. H., Smith, J. G., Lanphere, M. A., Dalrymple, G. B., Reed, B. L., and Shew, N., 1990, Age and progression of volcanism, Wrangell volcanic field, Alaska: Bulletin of Volcanology, v. 53, n. 1, p. 29-44.[2] Volcanoes of North America: United States and Canada, 1990
Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.[3] Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve, 1995
Richter, D. H., Rosenkrans, D. S., and Steigerwald, M. J., 1995, Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve: U.S. Geological Survey Bulletin 2072, 31 p.
Complete Eruption References
Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve, 1995
Richter, D. H., Rosenkrans, D. S., and Steigerwald, M. J., 1995, Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve: U.S. Geological Survey Bulletin 2072, 31 p.
Age and progression of volcanism, Wrangell volcanic field, Alaska, 1990
Richter, D. H., Smith, J. G., Lanphere, M. A., Dalrymple, G. B., Reed, B. L., and Shew, N., 1990, Age and progression of volcanism, Wrangell volcanic field, Alaska: Bulletin of Volcanology, v. 53, n. 1, p. 29-44.
Volcanoes of North America: United States and Canada, 1990
Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.
Hard Copy held by AVO at FBKS - CEC shelf