Eruption Episode 3 rocks, Clear Lake Volcanic Field, California

Detailed Description
Eruption episode 3 is the most voluminous in the history of the Clear Lake Volcanic Field. Episode 3 rocks are of intermediate composition, primarily dacite, and make up many of the topographic high points in the field, including Mt. Konocti, where this photo is taken. Episode 3 rocks commonly contain pieces of older rocks (and crystals) that were entrained within the erupting magma. USGS photo by Dawnika Blatter.
Sources/Usage
Public Domain.
USGS photo by Dawnika Blatter