Red beds, evaporites, and carbonates of the upper Clear Fork and Glorieta Formations (Permian) of the Texas Panhandle form an association of facies deposited in nearshore and supratidal environments along an arid coastline.

San Andres oil constitutes more than 80 percent of the total production from the Northern Shelf of the Midland Basin, Texas.

The San Andres evaporitic sequence in the Palo Duro Basin comprises several thick carbonate units in its lower part and many thin units in its upperpart. To the south, across the Northern Shelf of the Midland Basin, evaporites pinch out and carbonates predominate.

Regional cross sections of Middle and Upper Permian rocks in the Texas Panhandle illustrate the lithology, depositional systems, and structure of these salt-bearing strata.

The Salado-Tansill and Alibates Formations are the youngest evaporite and carbonate facies within a thick Permian sequence of evaporites, carbonates, and red beds in the Texas Panhandle.

The Texas Panhandle traditionally has been an important source of mineral resources, especially petroleum, and resources will continue to contribute heavily to the economy of the area. The seven cross sections of this report synthesize the subsurface geology of the region.

Pennsylvanian clastic and carbonate strata were deposited in a variety of environments within the Palo Duro Basin. Maximum accumulation (totaling 750 m or 2,400 ft) occurred along a northwest-southeast axis.

Samples collected from 20 geographically widespread wells in the sparsely drilled Palo Duro Basin were analyzed for total organic carbon content (TOC). Highest values of TOC, up to 6.9 percent, occur in Upper Permian San Andres dolomite in the southern part of the basin.

Lower Permian (Wolfcampian) strata of the Palo Duro Basin consist of thick, terrigenous clastic and carbonate facies that were deposited in (1) fan-delta, (2) high-constructive delta, (3) carbonate shelf and shelf-margin, and (4) slope and basinal systems.

The Neogene Ogallala Formation is an alluvial apron that occurs east of the Rocky Mountains from South Dakota to the Southern High Plains of Texas. The Ogallala was deposited by coalescent, low-gradient, wet alluvial fans that headed in mountains to the west.