- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of North American Geology, U. S. Geological Survey, Reston, VA, United States
Palynologic correlations between 3 cores 80, 90, and 120 mi apart of the Cretaceous Eagle Ford Group are compared with detailed electric log correlations carried between intermediate wells. The close agreement between these 2 correlation tools and a thick bentonite zone in lower Eagle Ford rocks illustrates the regional correlation value of palynomorphs in marine sediments. The appearance of a species of pollen from the genus Punctatricolporites roughly coincides with the Cenomanian-Turonian boundary in central Texas.