3
The rock around you is sandstone of the Cliff House formation, a member of the Mesaverde group of sedimentary rocks laid down in Cretaceous times—70 to 80 million years ago—near the edge of a shallow sea. When the shoreline retreated and the waters became shallower, and fresh or brackish, the sediments were in the form of carbonaceous shale and coal which are exposed across the canyon. The Indians made no use of the coal as fuel, but jet and shale from that formation were made into figurines, beads, and pendants, and decomposed shales were used for pottery clay and for mortar.
