Granite Platforms in the Wichita Mountains, Oklahoma: Pediment Outliers of the Southern High Plains in Texas and New Mexico

Abstract

Well-developed granite platforms exist near the summits of four of the highest hills in the Lake Altus area of the western Wichita Mountains in southwest Oklahoma. These features had previously been interpreted as wave-cut benches of Permian age. New evidence indicates that they are Pliocene pediments cut at the level of the Southern High Plains, which originally extended into western Oklahoma. During the late Pliocene and early Pleistocene, this surface retreated 180 km to its present position in the Texas Panhandle.