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One or more major gravity-slide thrusts have been documented in the Eola, Southeast Hoover, and Southwest Davis oil fields, and in the western Arbuckle Mountains, Garvin and Murray Counties, Oklahoma. The gravity-slide area initially covered portions of at least nine townships; it was more than 30 mi (50 km) long and 5-6 mi (8-10 km) wide. It involved a stratigraphic sequence greater than 5,000 ft (1,500 m), extending from the lower Springer Formation into the upper portion of the Arbuckle Limestone. The major slides moved to the northeast and northwest, probably in the Middle Pennsylvanian. Slides and faults were subsequently isoclinally folded in the Late Pennsylvanian. The tensional updip segment of the major folded slide fault now coincides with the trace of the Washita Valley fau t. The compressional end of the slide coincides with the Reagan fault in the east and the frontal Eola fault in the west. In the Lake Classen area the latest folding has turned all formations involved in the slide--and the associated faults--to a near-vertical position. Thus, the slide is exposed in a "profile view" on the south limb of the overturned Washita Valley syncline. On the north normal limb of the Washita Valley syncline, the slide is exposed in "plan view," with the Dougherty anticline and related folds representing compressional folding at the toe of the slide. Several tectonic breccias near the top of the Kindblade Formation of the Arbuckle Group probably mark the orogenic event.

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