Angular unconformity atop Mount Everts, Yellowstone National Park
Angular unconformity atop Mount Everts, Yellowstone National ParkAn unconformity at the top of Mount Everts is located where the Huckleberry Ridge Tuff, 2.1 million years old, lies directly on top of Cretaceous sediments that are ~60 million years old and greater. Right at the unconformity are conspicuous orange and black colors. The orange is oxidation of the sedimentary unit where it is in contact with the ash, whic