This study offers a high-frequency sequence stratigraphic model of carbonate-ramp strata of the San Andres Formation.

The San Andres Formation in the Palo Duro Basin is a middle Permian carbonate-evaporite sequence situated between two red-bed units, the underlying Glorieta and the overlying undifferentiated Queen-Grayburg sequences.

Fluid pressure, permeability, rates and patterns of ground-water flow, and chemical and isotopic composition of ground water in carbonate rock in the lower part of the San Andres Formation (Permian) in eastern New Mexico and the Texas Panhandle were studied to characterize the origin and movement

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.

The San Andres Formation on the Northern and Northwestern Shelves of the Midland Basin is a progradational stratigraphic unit consisting predominantly of carbonate facies. Lithofacies include dolomite, laminated anhydrite and dolomite, massive bedded anhydrite, limestone, salt, and red beds.