Is Lower Cretaceous formation mapped at north end of Chinati Mountains, west-central Presidio Co, TX (southern part of Permian basin). Overlain by Bluff Mesa Formation (Lower Cretaceous). Comprised of conglomerate, limestone, shale, marl, and sandstone. Upper part--low cliff-forming units alternating with softer material in slopes; characterized by red color from presence of red limestone, red and purple shale, and brown sandstone and the talus of these rocks; thickness 500 to 550 ft. Lower part--conglomerate resting on Permian rocks, well-rounded pebbles and cobbles of light-colored limestone, a scattering of variously colored chert, boulders of Pinto Canyon Formation (Permian) common near base, grades upward into nodular, fine-grained limestone and marl of overlying member; forms cliffs as high as 100 ft; thickness as much as 106 ft.

Source: GNU records (USGS DDS-6; Denver GNULEX).