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Global Volcanism Program | Image GVP-03348

The Mesa Falls Tuff is exposed in a quarry wall near Ashton, Idaho that shows light-colored airfall and pyroclastic-surge deposits overlain by orange-colored pyroclastic-flow deposits.  The 280 cu km Mesa Falls Tuff, deposited about 1.3 million years ago during the second of Yellowstone's three largest eruptions, resulted in the formation of the 16-km-wide Henrys Fork caldera west of Yellowstone National Park. Photo by Lee Siebert, 1994 (Smithsonian Institution).

The Mesa Falls Tuff is exposed in a quarry wall near Ashton, Idaho that shows light-colored airfall and pyroclastic-surge deposits overlain by orange-colored pyroclastic-flow deposits. The 280 cu km Mesa Falls Tuff, deposited about 1.3 million years ago during the second of Yellowstone's three largest eruptions, resulted in the formation of the 16-km-wide Henrys Fork caldera west of Yellowstone National Park.

Photo by Lee Siebert, 1994 (Smithsonian Institution).


Yellowstone