Southeastern Section - 70th Annual Meeting - 2021

Paper No. 5-7
Presentation Time: 10:20 AM

COMPLEX STRATIGRAPHY OF THE CRETACEOUS-PALEOGENE BOUNDARY IN NORTHERN MISSISSIPPI


BROUSSARD, Joshua, Mississippi State University, Department of Geosciences, 6616 Woodlake Lane, Ocean Springs, MS 39564

The Cretaceous-Paleogene extinction is notable as being the second largest mass extinction event in known geologic history. Evidence of this extinction event can be stratigraphically observed worldwide. In the southeastern United States (the former Mississippi Embayment), this extinction boundary can occur as a drastic and unconformable change, usually categorized by the presence of microspherules within the lowermost Paleogene sediments. Several stratigraphically similar outcrops have been documented along the former Mississippi Embayment, with some variations among them. Outcrops of the K-Pg boundary in Mississippi seem to go largely unnoticed, either due to their absence or similarity to outcrops much thoroughly document elsewhere. However, several outcrops recently found in northern Mississippi seems to exhibit the K-Pg boundary with exceptional and complex stratigraphy. The outcrops consist of several horizons of spherule bearing sand bodies and indurated surfaces overlying the Late Cretaceous Prairie Bluff Chalk and overlain by the Early Paleogene Clayton Formation. Within these outcrops, there are several notable variations, and each is bound by local faulting. These new outcrops provide another glimpse into the turbulent environment following the Cretaceous-Paleogene extinction.