Analysis of surface exposures of the Viola Limestone is important to understanding Viola oil and gas production trends in the Marietta basin of southern Oklahoma. Surface exposures of the Viola Limestone in the Arbuckle Mountains and Criner Hills of Oklahoma indicate a critical dependence of fracture development on structural position and lithology. Maximum fracturing occurs in tensional zones along fold crests, rather than in areas characterized by intense compressional stress. Fracturing also appears to be related to lithology. The basal, cherty unit has a fracture density approximately two to four times greater than that of the upper, more calcareous units. These relationships could be important to understanding oil and gas occurrence in the Viola Limestone, because th same controls may dictate distribution of fracture porosity in the subsurface.

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