Hermit Formation

The Permian Hermit Formation, also known as the Hermit Shale, is a nonresistant unit that is composed of slope-forming reddish brown siltstone, mudstone, and very fine-grained sandstone. Within the Grand Canyon region, the upper part of the Hermit Formation contains red and white, massive, calcareous sandstone and siltstone beds that exhibit low-angle cross-bedding. Beds of dark red crumbly siltstone fill shallow paleochannels that are quite common in this formation. The siltstone beds often contain poorly preserved plant fossils. The Hermit Formation varies in thickness from about 100 ft in the eastern part of the Grand Canyon region to about 900 ft in the region of Toroweap and Shivwits Plateaus. In the Sedona, Arizona area, it averages 300 ft in thickness. The upper contact of the Hermit Formation is typically sharp and lacks gradation of any kind. The lower contact is a disconformity characterized by a significant amount of erosional relief, including paleovalleys as much as 60 ft deep.

Popular Publications

 * Blakey, Ron and Wayne Ranney, Ancient Landscapes of the Colorado Plateau, Grand Canyon Association (publisher), 2008, 176 pages, ISBN 978-1934656037
 * Chronic, Halka. Roadside Geology of Arizona, Mountain Press Publishing Co., 1983, 23rd printing, pp. 229–232, ISBN 978-0-87842-147-3
 * Lucchitta, Ivo, Hiking Arizona's Geology, 2001, Mountaineers's Books, ISBN 0-89886-730-4