In the western Gulf Coastal Plain area the Jurassic Norphlet Formation is typically characterized by non-marine and red bed lithofacies. In south Alabama the Norphlet consists of an updip conglomerate, a discontinous basal shale, red beds overlying the shale, and an upper quartzose sandstone, the Denkman Member. The Norphlet uncomformably overlies either salt, anhydrite, red beds, or Paleozoic rocks. The Smackover Formation, which overlies the Norphlet, has a sharp contact with the Norphlet over most of the study area except in parts of Mobile County.