The Fort Worth Basin-Muenster Arch area, as covered by this paper, is bounded by Latitude 3 2° 15′ to 34°, and Longitude 96° 20′ to 98°. The area covers about 9,400 square miles, of which 90 square miles are now productive of oil and gas, in more than 50 oil and gas fields. Sedimentary rocks range in thickness from about 1,000 feet on the Muenster arch to 17,000 feet in the deepest part of the Fort Worth basin, with a total volume of about 17,000 cubic miles of sedimentary material. Producing depths range from the minimum of 500 feet to the maximum of 8,900 feet in Cooke County. The deepest test well is the Denver Producing and Refining Company's Rich No. 1, Grayson County, which was drilled to the total depth of 13,352 feet, stopping in Ellenburger limestone. More than 6,835 wells have been drilled in the area.

The Fort Worth basin is a regional syncline approximately 150 miles in length, varying in width from a few miles to 70 miles, and trending northwest. It is bounded on the west by the Bend arch, west of Palo Pinto and Jack counties, on the north and northeast by the Red River-Muenster buried ridges, and on the southeast by the Ouachita zone of folding and faulting. Rocks of Cambrian, Ordovician, Mississippian, Pennsylvanian, Permian, and Cretaceous age are present in the basin. Major unconformities are present at the base of the Mississippian strata, at the base of the rocks of Pennsylvanian age, in the