|Oligocene, Gulf Coast, Gulf of Mexico
The Frio is a very productive unit. We digitized a generalized map of Frio production from Galloway and others (1982).
Galloway, W. H., Hobday, D. K., and Magara, Kinji, 1982, Frio Formation of the Texas Gulf Coast Basin—depositional systems, structural framework, hydrocarbon origin, migration, distribution, and exploration potential: The University of Texas at Austin, Bureau of Economic Geology Report of Investigations No. 122, 78 p.