LATE PLEISTOCENE PALEOENVIRONMENTAL CHANGES IN THE LOWER NEUSE RIVER BASIN, NORTH CAROLINA AND IMPLICATIONS FOR COASTAL EVOLUTION

The coastal plain of eastern North Carolina evolved through the changes associated with late Pleistocene rapid relative sea-level change during Marine Isotope Stage 5 (MIS 5; 130 to 71 ka) and Marine Isotope Stage 3 (MIS 3; 55 to 29 ka). The evolution of this low gradient coastal system is defined by characteristics (chronology, stratigraphy, sedimentology, micropaleontology) of the deposits formed in response to multiple sea-level oscillations. The sea-level highstands of MIS 5 and MIS 3 have been previously studied in eastern North Carolina. However, certain regions have had little to no data collected, which makes determining the areal extent of facies and associated depositional environments challenging. To overcome these limitations and better understand the spatial and temporal variation of sea-level fluctuations, geophysical and geological data from the Lower Neuse River Basin (Pamlico and Craven Counties, NC) are being analyzed. The chronological framework, determined using optically stimulated luminescence dating, provides sediment age estimates of 139.9 (± 9.3) ka to 85.7 (± 5.3) ka. During this time, the presence of foraminiferal assemblages (including Buccella frigida, Nonionella atlantica, Rosalina sp.) suggest an open shelf environment with normal marine salinity in the study area. Lithofacies and grain-size statistics support shoreface and shelf environment settings, and pollen analysis suggests paleoclimatic conditions similar to modern conditions. The results of this study can be used to understand the regional stratigraphic framework and aid in developing projections of future coastal evolution of North Carolina.