EVIDENCE FOR WIDESPREAD EOLIAN ACTIVITY IN THE COASTAL PLAIN UPLANDS OF NORTH AND SOUTH CAROLINA REVEALED BY HIGH-RESOLUTION LIDAR DATA

High resolution LiDAR (Light Detection and Ranging) elevation data have been available in North Carolina for several years and were produced by the North Carolina Floodplain Mapping Program (http://www.ncfloodmaps.com/) in response to Hurricane Floyd in 1999. Since that time, South Carolina has initiated a Statewide LiDAR Consortium where individual counties working with state and federal agencies have produced LiDAR data for participating counties. These data are now becoming available to researchers and offer potential to investigate large-scale, low-relief geomorphic features not visible or easily recognizable prior to the collection of LiDAR data.

An analysis of LiDAR data for various coastal counties in North Carolina along with areas recently made available in South Carolina have revealed visual evidence for widespread and large-scale (i.e., kilometers long) eolian activity in the Coastal Plain uplands. These generally low-relief geomorphic features include large swaths or ribbons of coalescing parabolic dunes, transverse or nested parabolic dunes, flat blowout regions near the point of dune origin, and hummocky terrain typical of eolian geomorphic features. Although dune topography in the Coastal Plain has been recognized and mapped prior to the development of LiDAR, these deposits appear to represent an under-recognized or at least under-appreciated geomorphic feature within many areas of the Coastal Plain of North and South Carolina. Eolian features appear associated with dominant westerly winds within flat upland regions of the Coastal Plain and often originate from incised upland terraces and incised headwater regions of small upland feeder streams. As such, eolian deposition may be linked to periods of downcutting and fluvial incision-providing a sand source for eolian remobilization downwind of incised terraces and streams. These dunes, although likely Pleistocene in origin, have implications for archaeological sites in the Coastal Plain uplands where limited Holocene reworking of a plentiful sand source may have contributed to site burial and preservation. Future work should focus on ground truthing these features to verify an eolian origin along with the application of luminescence (OSL) dating to determine the timing of eolian events and linkages to regional paleoclimate data.