Mesozoic of the Gulf Rim and Beyond: New Progress in Science and Exploration of the Gulf of Mexico Basin

Stratigraphy of Fredericksburg-Washita Division (Albian), Comanche-Cretaceous, Texas, Emphasizing Person and Georgetown Formations
email: [email protected]
-
Published:December 01, 2016
-
CiteCitation
Peter R. Rose, 2016. "Stratigraphy of Fredericksburg-Washita Division (Albian), Comanche-Cretaceous, Texas, Emphasizing Person and Georgetown Formations", Mesozoic of the Gulf Rim and Beyond: New Progress in Science and Exploration of the Gulf of Mexico Basin, Christopher M. Lowery, John W. Snedden, Norman C. Rosen
Download citation file:
- Share
Abstract
A regional network of five interlocking stratigraphic cross-sections compiling the published work of many geologists throughout central and southwest Texas demonstrates the true stratigraphic relationships among formations of the Lower Cretaceous Fredericksburg and lower Washita subcycles. Strongly supported by a long-established ammonite zonation, these detailed stratigraphic cross-sections show lateral relations between Edwards Group formations (Kainer, Person, Fort Terrett, Segovia, Fort Lancaster, and Devils River) of the Central Texas Platform with equivalent formations of the East Texas Basin (Walnut, Comanche Peak, Goodland, Georgetown) and the Maverick Basin of South Texas (West Nueces, McKnight, Salmon Peak). These cross-sections document the following regional stratigraphic relationships:
The Burt Ranch Member (basal Segovia Formation), the Regional Dense Member (basal Person Formation), and the Kiamichi Member (basal Georgetown Formation) are stratigraphic equivalents, all three being in the Adkinsites bravoensis Ammonite Zone (lowermost Washita)
The peritidal Person Formation is the shelf-interior equivalent of the pelagic-shelf Georgetown Formation, except for its uppermost member, the Main Street, which forms the thin remnant Georgetown Formation on the distal Central Texas Platform.
Thus the Person Formation is properly assigned to the lower Washita subcycle, not the Fredericksburg.
- Albian
- Ammonites
- Ammonoidea
- Balcones fault zone
- biostratigraphy
- biozones
- Cephalopoda
- Comanchean
- correlation
- Cretaceous
- cross sections
- East Texas Basin
- Edwards Formation
- Fredericksburg Group
- Georgetown Formation
- lithofacies
- Lower Cretaceous
- Maverick Basin
- Mesozoic
- Mollusca
- San Marcos Arch
- Texas
- thickness
- United States
- Washita Group
- Central Texas Platform
- Burt Ranch Member
- Segovia Formation
- Person Formation
- Kiamichi Member
- Regional Dense Member