This report combines borehole core and geophysical log study with porosity and permeability data to define patterns of facies and permeability distribution in a typical upper Clear Fork reservoir in the Permian Basin. Key findings are that permeability, but not porosity, varies markedly with facies and that spectral gamma ray logs are critical for defining facies, facies architecture, and reservoir quality.

Beautifully illustrated by more than 100 photos and diagrams, this nontechnical guide surveys the geologic evolution of Mustang Island and the relationship between physical setting and biologic environments along the Texas coast. Support was provided by the National Oceanic and Atmospheric Administration under the Texas Coastal Management Program, administered by the Texas General Land Office, and by the Texas Parks and Wildlife Department.