A NEW STRATIGRAPHIC FRAMEWORK FOR CRETACEOUS COASTAL PLAIN SEDIMENTS WITHIN THE CAPE FEAR RIVER BASIN, NORTH CAROLINA
Detailed lithologic and biostratigraphic examination of 32 outcrops along the Cape Fear River and the two core holes has shown that the majority of the (unconformity-bounded) stratigraphic units identified in South Carolina are present in outcrops on the river and(or) in the two core holes. In summary, the unit historically identified as the Cape Fear Formation contains at least three unconformable depositional subunits, the unit historically identified as the Black Creek Formation (Group) contains at least ten unconformable depositional sequences, and the unit historically identified as the Peedee Formation contains at least three unconformable depositional sequences. These sequences, which most likely represent changing sedimentation patterns in response to sea level rise and fall, are lithologically and biostratigraphically distinct, and their bounding unconformities can be traced from corehole to outcrop. Although the lithofacies change in a downdip direction, these “sequences” remain unconformity-bounded stratigraphic units characterized by diagnostic biozones. In addition, the continuity of these formations suggests that no major faults or folds vertically offset these layers along the line of section.