Indications of a post-Mississippian event emerged after geologic mapping (Bucher 1933; Reidel 1975; Reidel and others 1982) suggested that the Lower Mississippian Cuyahoga Formation was the youngest geologic unit to have been deformed by the impact event.
The authors, basing an interpretation solely on the size and shape of the grains in those shale clasts, suggest that the clasts belong to the Upper Devonian Ohio Shale or Lower Mississippian sandstones of the Cuyahoga Series.
Specimens of rodent-gnawed rock which are the principal basis for this study consist of impure, fine-grained carbonate rocks, including one sample from the lower Mississippian
Rockford Limestone and one from the middle Mississippian Ramp Creek Formation.
Fortune has acquired a 20% working interest in new prospect in Mississippi to test a deeper Lower Mississippian
trend, Pennsylvanian Sands and Ordovician Dolomite in the Black Warrior Basin.
In November, the well was shut in to permit deepening of the well into the lower Mississippian