The 3-fold series terms Lower, middle, and Upper Permian are replaced with a 2-fold classification, Lower and Upper Permian. Rocks above the base of the Whitehorse Formation are classified as Upper Permian. The West Texas Permian stage names, Wolfcampian, Leonardian, Guadalupian, and Ochoan are replaced with locally-derived stage names, Gearyan and Cimarronian. The Permian rock-stratigraphic unit "Taloga Formation" is abandoned and replaced with "Big Basin Formation." One additional member, Kiger Shale, is recognized in the Whitehorse Formation. The Pennsylvanian group term "Pedee" is abandoned. The Douglas Group is amended and redefined to include units previously included in the Pedee Group in addition to the stratigraphic units previously included.

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