CRETACEOUS-PALEOGENE BOUNDARY SEDIMENTOLOGY: IMPACT EVIDENCE FROM SOUTH CAROLINA

The Cretaceous-Paleogene (KPg) boundary is one of the most intensely studied stratigraphic sections from Earth history. Even so, the stratigraphic sections marking the boundary in South Carolina remain largely unexamined. Petrographic thin sections were made from samples collected directly below, from, and above the KPg boundary in exposed strata in South Carolina and in a well-studied locality from North Dakota. Thin sections were examined via standard and polarized light microscopy for the primary mineralogical indicators of the boundary, including impact microspherules and shocked quartz. Glass microspherules were observed in the boundary sediments from both South Carolina and North Dakota. Shocked quartz was observed in only the boundary sediments from South Carolina. Neither microspherules or shocked quartz grains were identified in sediments from below or above the KPg boundary clay layer. Although our sample size is small, the confirmation of a KPg boundary site near Columbia, South Carolina is significant, as it provides potential for further research and educational opportunities.