Subsurface Structural Geology of the Potato Hills area of the Ouachita Mountains, Southeastern Oklahoma.

By

Gultekin Kaya and Ibrahim Cemen; School of Geology, Oklahoma State University,  Stillwater, OK 74078

The Late Paleozoic Ouachita Orogeny formed the Ouachita Mountains of southeastern Oklahoma and western Arkansas. The Potato Hills area is located to the south of the Frontal Ouachitas and contains lower and middle Paleozoic strata. The exposed rock units range from Middle Ordovician Womble Shale to the Mississippian Stanley Group. Recently, gas production from Jackfork and Stanley group has been very important in the area.

This study is an attempt to reconcile the structural geometry of Late Paleozoic thrusting in the Potato Hills area with the Frontal Ouachitas. In the Potato Hills area, there are three major thrust faults exposed on the surface and there are several blind thrusts in the subsurface. Five balanced structural cross sections are being constructed to better understand the subsurface geometry of thrusting in the Potato Hills area. At least, two of these cross-sections will be extended northward to the Wilburton gas field area where previous workers have already established the structural geometry.

Well logs, seismic data, topographic maps, geologic maps and several computer programs are being used to construct the cross sections. Our preliminary interpretation suggests that the Windingstair fault is a major discontinuity within the Ouachita Mountains. It separates a zone of imbricate reverse faults to the north (frontal Ouachitas) from a zone of broad syncline structures separated by sharp anticlines or high angle faults (central Ouachitas). Windingstair fault is a high angle fault at the surface. However, it gets almost horizontal at depth. We intend to delineate its structural relationship with the Woodford and Choctaw Detachment surfaces.

AAPG Search and Discovery Article #90010©2003 AAPG Southwest Section Meeting, Fort Worth, Texas, March 1-4, 2003