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Capital reported activity



Event Name : Capital 1090000 yBP

Start: 1090000 Years BP K-Ar
Stop: 1020000 Years BP K-Ar

Lava flow: BibCard BibCard BibCard
Eruption Type:Effusive
Eruption Product: other BibCard

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."

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Page modified: March 30, 2017 14:36
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