Stuart City Trend, Lower Cretaceous, South Texas: A Carbonate Shelf-Margin Model for Hydrocarbon Exploration

Abstract

Lower Cretaceous shallow-water carbonates accumulated on a broad shelf which completely encircled the Gulf of Mexico. Biogenic growth climaxed along the basinward edge, or shelf margin, where a complex of reefs, banks, bars, and islands developed. The sediments reached a total thickness of 2000 to 2500 feet; numerous deep wells ranging in total depth from 11,000 to 20,000 feet have resulted in the discovery of a few marginally productive gas fields. The depositional facies and environments present along this trend are described in order to provide a model for further hydrocarbon exploration along the Stuart City Trend and also in the deeper Sligo Trend, and to identify diagenetic processes which relate to porosity distribution and might lead to the discovery of zones of higher porosity elsewhere along the trend are identified.