ABSTRACT

Since the discovery of oil in the Lower Cretaceous Edwards formation near Luling, Caldwell County, Texas, in August of 1922, about 234,000,000 barrels of oil have been produced from five fields, with two fields accounting for about 200,000,000 barrels. Although shows have been encountered in the Edwards formation in Travis, Bastrop, Lee, Milam, Bexar, Wilson and Gonzales counties, commercial production has been limited to an area near the crest of the San Marcos Arch in Caldwell and Guadalupe counties, Texas. Closure against up-toward-the-coast faults forms the traps for the fields. These faults were all located by surface geology. A small amount of production has been obtained from the Buda formation of Lower Cretaceous Washita age, which is unconformable beneath the Upper Cretaceous Eagleford formation. At present, no production has been established in beds older than the Edwards formation in south central Texas.