Mesa Falls ash-flow tuff and underlying fallout ash near Ashton, Idaho

Mesa Falls ash-flow tuff and underlying fallout ash exposed in a qu...

Detailed Description

This area was near the depositional margin of the ash flows and consequently the ash-flow tuff is nonwelded and contained abundant large pumice blocks. The tuff was deposited during a large eruption that produced the Henrys Fork caldera southwest of Yellowstone National Park 1.2 million years ago.

Details

Image Dimensions: 800 x 500

Date Taken: