Cenomanian-Turonian flooding cycles: U.S. Gulf Coast and Western Interior

This new database calibrates numerical ages of Cenomanian-Turonian sequence boundaries in Tunisian reference sections. These deep-shelf successions of limestone/marl/shale record biostratigraphically well dated, continuous deposition and serve as a model of Cenomanian-Turonian cycles. The Cretaceous database enables stratigraphic correlation experiments to test the time equivalency of Tunisian depositional cycles with sequences in Europe, in the Eagle Ford Group in Texas and with stratigraphic sequences in the Western Interior. New accurate and precise correlation of Cenomanian-Turonian depositional sequences between the Gulf Coast and the Western Interior test new biostratigraphic and radioisotopic data of the Eagle Ford Group on the Texas Comanche shelf. The Albian-Cenomanian boundary as defined by planktic foraminifers and ammonites in Texas projects between upper Albian shale units and the Dakota Group and associated sandstone units. The Mowry Shale and its endemic ammonites correlate with upper lower Cenomanian zones.