along wrench faults and associated fracture zones from underlying Cretaceous and Jurassic source rocks. See also List of fossiliferous stratigraphic units in Alabama List of fossiliferous stratigraphic units in Louisiana List of fossiliferous stratigraphic units in Mexico List of fossiliferous stratigraphic units in Texas Paleontology in Alabama Paleontology in Louisiana Paleontology in Texas Wilcox Formation References Further reading Geologic groups of Alabama Geologic groups of Georgia (U.S. state) Geologic groups of Louisiana Geologic groups of Maryland Geologic groups of Mississippi Geologic groups of North Carolina Geologic groups of South Carolina Geologic groups of Texas Geologic groups of North America Paleogene United States Geologic formations of Mexico Paleogene Mexico Selandian Stage Thanetian Stage Ypresian Stage Bartonian Stage Mudstone formations Reservoir rock formations Source rock formations Gulf of Mexico Geography of Nuevo León Geography of Tamaulipas