PALEOENVIRONMENTAL CHANGES RELATED TO RAPID SEA-LEVEL RISE DURING THE LATE PLEISTOCENE IN THE LOWER NEUSE RIVER BASIN, NORTH CAROLINA

The coastal plain of eastern North Carolina evolved through the rapid relative sea-level changes of the late Pleistocene during Marine Isotope Stage 5 (MIS 5; 130 to 71 ka) and Marine Isotope Stage 3 (MIS 3; 55 to 29 ka). The sea-level highstands of MIS 5 are marked by the Suffolk Shoreline (120 km inland from the modern ocean shoreline); associated transgressive and highstand deposits occur east of the shoreline. MIS 3 highstand deposits are less extensive and occur north of the Neuse River Estuary study area. Lithofacies and geophysical data indicate that transgressions during MIS5 and MIS3 may be comparable to projected future sea-level rise and associated transgressions over multi-decadal to centennial scales. To better understand the temporal and spatial variation of sea-level fluctuations, and the corresponding evolution of the coastal system, nine cores, placed in a geophysical context, from near the southern end of the Suffolk Shoreline (Pamlico and Beaufort County, NC) are being analyzed using micropaleontology (foraminifera) and sedimentology to reconstruct the paleoenvironments. The chronological framework, determined using optically stimulated luminescence dating, provides age estimates of 139.9 (± 9.3) ka to 85.7 (± 5.3) ka. During this time, foraminiferal assemblages (including Buccella frigida, Nonionella atlantica, Rosalina sp.) indicate an open shelf environment with normal salinity waters existed in the study area.