Structural Geometry of Thrust Faulting in the Hartshorne area of Frontal Ouachitas, Arkoma Basin, Oklahoma

By

Steve Hadaway and Ibrahim Cemen; School of Geology, Oklahoma State University,  Stillwater, OK 74078

The Ouachita Mountains and Arkoma basin are two related tectonic provinces formed during the Late Paleozoic Ouachita Orogeny. The Arkoma basin consists of gentle synclines and thrust-cored anticlines. The frontal Ouachitas are characterized by imbricate thrusts and complex fold geometries.

This study is concerned with the structural geometry of thrusting within the Hartshorne SW quadrangle in southeastern Oklahoma. The study area includes the Hartshorne gas field where gas production ranges from five bcf in 17 months (middle Atoka from Agnes #1 well) to numerous dry holes.

Five balanced structural cross-sections are being constructed to determine the geometry of the Late Paleozoic thrust system. Data from the surface geological maps by the Oklahoma Geological Survey, wire-line well logs, scout tickets, and seismic profiles, from BPAmoco and ExxonMobil Corporations are used to construct the cross-sections. Upon their completion, the cross-sections will be restored to determine the amount of shortening induced by thrusting in the area.

The Hartshorne, Red Oak, Panola, Brazil, and Spiro sandstones are identified as marker beds to construct the cross-sections. We considered the Spiro to include the Wapanucka and Cromwell formations.  Our preliminary interpretation of the available data suggest that a triangle zone exists between the Carbon Fault to the northwest and the Choctaw Fault to the southeast. A duplex structure and associated horses appear to exist above the Woodford and Springer detachments with the Lower Atokan Detachment as the roof thrust.

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