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Eruption Episode 4 rocks, Clear Lake Volcanic Field, California

Detailed Description

The cinder cone in the distance is Round Mountain, which is being actively quarried for road rock. Eruption episode 4 is the most recent in the Clear Lake Volcanic Field, and is characterized primarily by lava flows, cinder cones (like the one pictured), and maar deposits. The lava flows near High Valley are episode 4 flows, as are the maar craters located along the western shore of Clear Lake. Eruption episode 4 is characterized primarily by basaltic andesite compositions, similar to those erupted during Episode 1. USGS photo by Dawnika Blatter.

Sources/Usage

Public Domain.

USGS photo by Dawnika Blatter

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