Roadcut in the Lava Creek Tuff near Tuff Cliff, Yellowstone National Park

Roadcut in light pink ash-flow deposits of the Lava Creek Tuff on Grand Loop Road near Tuff Cliff.  The color and closely spaced jointing are characteristic of the Lava Creek Tuff map unit.  The steep faces and dense nature of the roadcut exposures indicate that a moderate degree of welding occurred and has not been subsequently modified by hydrothermal alteration.  Photo by Richard Tollo, George Washington University, August 13, 2008.