| This trip is at Sinker Butte, which is about 60 miles south of Boise, Idaho. The trip focuses on the sequence of basaltic hydrovolcanic deposits that were erupted from a large emergent Snake River Plain volcano and are now spectacularly well exposed in the walls of the Snake River Canyon. Stops are at localities where deposits having subaqueous and subaerial origins are represented and include the complete sequence of deposits produced at this volcanic center. Volcanism ended with strombolian scoria, spatter, and lava flows. |