Upper Tertiary Surficial Deposits near Cedar City, Iron County, Utah

Abstract

Along the Hurricane fault in southwestern Utah, fanglomerate, pediment, and stream-channel deposits ranging in age from Miocene(?) to Recent have been dated through studies of the composition and size of gravel components and distance from sources of materials. The deposits range in elevation from 6000 feet at the base of the Hurricane Cliffs on the west, or downthrown side of the Hurricane fault, to 9000 feet on the Kolobterrace on the east, or upthrown side of the fault. Much of the difference is the result of displacement on the fault in Pliocene and Pleistocene time. Differences in composition of gravel also establish the existence of an approximate late Tertiary drainage divide between two westward-flowing streams that formerly headed about 8 miles east of the Hurricane fault. The channels of these streams have since been obliterated by uplift, erosion, and basalt flows.