Up-close view of the Peach Spring Tuff - welded volcanic ash - from the Silver Creek caldera, near Oatman, Arizona. The Peach Spring Tuff was emplaced about 18.9 million years ago during a supereruption of the Silver Creek caldera.
Ferguson, C.A., 2016, The Peach Spring Tuff, its source caldera, and implications for structural geology of the Colorado River Extensional Corridor. Arizona Geological Society 2016 Fall Field Trip, 29 p. http://repository.azgs.az.gov/uri_gin/azgs/dlio/1878
