Grey’s Landing Ignimbrite in Idaho part of Yellowstone Hotspot

The Grey’s Landing Ignimbrite in Idaho (Dr. Thomas Knott, of the University of Leicester, England, gives the scale of the cliff). The entire cliff (and more not seen!) would have been deposited in a matter of moments as it welded to the land surface during a super eruption about 8.7 million years ago. The bright orange layer at the base of the cliff represents the upper land surface soil at the time of the eruption, which was burnt and baked to terracotta by the heat of the ash flow.