Lower Permian (Wolfcampian) strata of the Palo Duro basin consist of 1,000 to 2,000 ft (300 to 600 m) of terrigenous clastic and carbonate sediments which were deposited in basin, slope, shelf-margin, shelf, and deltaic environments. Lateral and vertical sequences of facies throughout the basin indicate that these strata are regressive and document the first episodes of Permian marine retreat from the Panhandle region of Texas.

Terrigenous clastic sediment was derived from highlands which surrounded part of the Palo Duro basin. Exposed Precambrian granite in the Amarillo uplift, Sierra Grande uplift, and Bravo dome yielded large quantities of arkosic sand (granite wash) to fan-delta systems which emptied into shallow-marine environments in the northern part of the basin. Along the basin's southeastern margin, high-constructive deltas prograded westward from the Wichita Mountains depositing quartz-rich sand and mud across the shelf.

Seaward of the clastic-facies belt, an arcuate, carbonate-shelf-margin complex, averaging 1,000 to 1,200 ft (300 to 360 m) in thickness and facing south toward the Midland basin, dominated Wolfcampian deposition. The western shelf margin consists of a superposed sequence of carbonate strata exhibiting limited basinward progradation. In contrast, the eastern shelf margin is composed of several superposed, progradational carbonate sequences, individually averaging several hundred feet in thickness. During early to middle Wolfcampian time, the eastern shelf margin prograded westward 10 to 30 mi (16 to 48 km) but the western margin remained stationary. Shelf margins shifted in response to deposition of slope sediments in front of the shelf, creating a foundation for subsequent carbonate b ildups. Slope deposits consist of (1) hemipelagic mud, (2) fine-grained clastic sediments transported downslope

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through submarine canyons incised in the shelf margin, and (3) redeposited carbonate sediment derived from shelf-margin buildups.

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