Deposition from a series of lakes then dominate the geologic record, resulting in the locally 150 to 200 foot (45 to 60 m) thick Owl Rock Member of the Chinle. The Owl Rock is made of purple and orange mudstones, fine-grained sandstones and siltstones with interbedded 1 to 10 foot (30 to 300 cm) thick green to mottled pink micritic and knobby limestone. Fossilized desiccation mudcracks that are up to 4 inches (10 cm) wide and 3 feet (1 m) deep are found at the very top of the Owl Rock (they were later filled with sand from the overlying Wingate Sandstone). Also found in the Owl Rock are trace fossils of cylindrical burrows and fossils of ostracodes. The Owl Rock erodes into littered slopes and is found directly below the Wingate Sandstone along the Waterpocket Fold's west face.