Transgressive shoreline deposits seaward of coastal ponds along northeastern South Carolina coastline.

The arcuate Long Bay coastline of northeastern South Carolina is dominated by the 75 km long Grand Strand, which is the result of landward retreat of the shoreline intersecting the paleo Myrtle Beach barrier system. As the shoreline transgresses, three stages of development have been recognized in this large coastal embayment: (1) coastal barrier island landforms north and south of the central Grand Strand that are migrating across an irregular Pleistocene paleolandscape and have not intersected emergent Quaternary paralic terraces; (2) an intermediate stage where the transgressing shoreline has created shore parallel coastal lakes and vegetated wetlands between the transgressive sediment mass and the emergent terraces; and (3) coastal segments where the transgressive shoreline is actively eroding into the emergent Pleistocene core. This study uses ground penetrating radar (GPR) and vibracore data to study the intermediate stage lake coastline. The GPR data reveals landward dipping reflectors infilling uneven topography and channels formed in the low between the irregular paleo barrier high and retreating shoreline. Study of the transgressive architecture and intersection with paleo- shoreface is important for understanding future shoreline retreat and for understanding potential storm records preserved in the infill.