Westwater Canyon - Geology

Geology

The geology of Westwater Canyon is very similar to nearby National Parks such as Canyonlands National Park, Colorado National Monument, and Arches National Park. The uppermost rocks in the canyon date from the Triassic period and are composed of the reddish, cliff-forming Wingate Sandstone atop the green to purple, slope-forming Chinle Formation. Within the inner gorge of Westwater, a large unconformity separates the Chinle Formation from the Precambrian basement rocks composed of metamorphic Vishnu Schist (black) and Zoroaster Granite (pink). Westwater Canyon and Ruby Canyon are the only places on the Colorado River outside of the Grand Canyon where Precambrian rocks are exposed.