ABSTRACT

The Pennsylvanian sediments studied are in northwestern Oklahoma and adjacent portions of the Texas Panhandle. These rocks range in thickness from 2,000 feet in Woods County at the north to 15,000 feet in Beckham County at the south. At the Wichita Mountain front in Beckham County, the sediments above the Morrowan are essentially coarse grained sands and "granite wash." On the inner shelf siltstones and shales predominate; and these grade northward to shales, siltstones, sandstones, and carbonates on the outer shelf. Morrowan rocks of Early Pennsylvanian age are predominantly clastic throughout with a basal sandstone grading upward into shale. The Morrowan is unconformable with and onlaps Springeran and Chesterian rocks. The Morrowan, Springeran, Chesterian, Meramecian, and Osagean are in turn overlapped by the Desmoinesian-Atokan rocks.

Marginal uplifts to the north and east are thought to have accompanied basin subsidence from Springeran through a portion of Desmoinesian time. Subsidence continued throughout most of Missourian time, with interruptions indicated by sedimentary character, but became insignificant after early Virgilian. Silling of the basin occurred approximately at the end of Shawnee time, possibly dating the Arbuckle orogeny; and filling of the basin is marked by the evaporitic sequence of early Leonardian time.