On the south side of the river from Bright Angel Campground the cliffs of Upper Granite Gorge display evidence of the Cremation Graben; here, the rocks are comprised of crystalline basement, Brahma Schist intruded by pinkish, Zoroaster Granite and overlain by a rare slab of sedimentary rocks consisting of the Grand Canyon Supergroup’s Bass Formation and Hakatai Shale.