The development of the Pine Island deep sands followed the exhaustion of the oil from the so-called "Woodbine" sand.

The Glen Rose limestone is found in the Pine Island field immediately below the "Woodbine" sand at an approximate depth of 2,300 feet. The Washita-Fredericksburg sediments were deposited and eroded from the crest of the dome but occur around the flanks of the Pine Island uplift.

The Trinity group in this paper is separated into upper Glen Rose, 200 feet; anhydrite zone, 450 feet; lower Glen Rose limestone, 900 feet; and red shale and sand zone, 2,000 feet.

The main structural features of the region are the gentle folding of the Upper Cretaceous, which involves the entire area of the northern Sabine uplift and the more intense folding of the Comanche. The latter is confined to the Pine Island field. No faulting of any considerable magnitude is present.

Three oil zones and one gas horizon have been developed to date in the Comanche sediments of Pine Island.

The field has been outlined by dry holes, and the possibilities of deeper production are yet unknown.