ABSTRACT

The Anahuac and Frio sediments in the subsurface of South Louisiana are reviewed and a formal type section for the Frio Formation and Stage is proposed in order to satisfy the Rules of Stratigraphic Nomenclature as defined by the Stratigraphic Commission. Although the procedure would be irregular, it is proposed that the term Frio be suppressed in its original usage for certain surface outcrops in Texas and be applied as the legitimate name for those subsurface beds between the Anahuacian and the Vicksburgian in Texas and Louisiana. The treatment of Anahuac and Frio stratigraphy in this report is necessarily brief; time was not sufficient to permit any more detailed descriptions. A more comprehensive paper is being prepared for publication at a later date which will contain an alternate type log for the Frio sediments and a detailed dip section to illustrate clearly the difference between stage and formation concepts of the Anahuac and Frio sediments.

Structural contour maps and several cross sections of a very generalized nature are included to illustrate the various features of the combined Anahuac-Frio section in South Louisiana. The approximate tops of the Heterostegina Zone and the Vicksburgian are the reference data used.

A list of fields which have production from the Anahuac-Frio section and a brief outline of reservoir types are also included.