Concentrations of jasper in carbonate rocks of the Supai Group, Toroweap Valley measured section. Grand Canyon National Park, Mohave County, Arizona. No date.

Album caption and index card: Concentrations of jasper in carbonate rocks of the Supai Group, Grand Canyon region. A, Irregular layers or "bands" of deep-red jasper alternating with layers of light-gray limestone in massive bed. Individual jasper layers are mostly 2-4 inches thick. Massive cliff unit of Manakacha Formation. Toroweap Valley measured section. Grand Canyon National Park. Mohave County, Arizona. n.d. Published as Figure R3-A in U.S. Geological Survey. Professional Paper 1173. 1982.