Abstract
Measured sections of late Miocene basalt lava flows, Tertiary gravel, and Paleozoic strata are the basis for stratigraphic reconstructions that provide evidence for pre- and post-volcanic movements on the Oak Creek fault, and for the existence of a prevolcanic ancestral Oak Creek Canyon, Arizona. Recurrent faulting, recording Laramide compression and Basin and Range extension, suggests probable control by an ancestral Oak Creek fault that would belong to a regional system of basement faults that have controlled Colorado Plateau structures in Phanerozoic rocks. Locally derived Tertiary gravel and overlying lavas filled a canyon eroded in Paleozoic strata along the Oak Creek fault. Southward flow of ancestral Oak Creek, indicated by the lithology and geomorphic position of the gravel, valley reconstruction, and lava vents to the north, northeast, or east, requires that the regional drainage reversal on the southern Colorado Plateau occurred before late Miocene time in the Oak Creek area.
