Paper No. 7
Presentation Time: 2:45 PM
CAPE LOOKOUT COASTAL SYSTEM: GEOLOGIC FRAMEWORK CONTROLS ON LATE HOLOCENE EVOLUTION, CAPE LOOKOUT NATIONAL SEASHORE, NC
Cape Lookout National Seashore is a 90 km long, natural barrier island system where pre-Columbian Native Americans had short-term camps, and later Europeans had small subsistence villages. Today, the isolated islands have no permanent residents and experienced only minor human modification. The Cape Lookout (CL) coastal system has two major geomorphic components. Core Banks and Core Sound are located NE of CL and consist of a 76 km-long inlet and overwash dominated barrier island and an adjacent shallow estuary dominated by recent sand shoals. Shackleford Banks (SB) and Back Sound (BS) are situated W of CL and consist of a 14 km-long barrier island and an adjacent broad estuary characterized by drowned paleo-topography. Recent studies (geomorphic mapping, ground-penetrating radar surveys, radiocarbon age dating, and NPS archeological surveys) suggest a more complex evolutionary history for SB and CL then previous studies indicated. The primary control in this history of the last 3 millennia was a 2-3 m sea-level rise that drowned the paleo-geography of Carteret Peninsula, a topographic headland with an incised drainage system. Second-order controls were island orientation, sand supply, and patterns of climate change.
Native American middens on SB date from the Early, Middle, and Late Woodland periods. Early to Middle Woodland middens (ca. 2700-1600 BP) occur on the W end of an older land surface. At the time of occupation, these middens were 2-3 m above and on the E side of vast flood-tide delta shoals associated with paleo-Beaufort Inlet. A narrow tidal estuary existed in a paleo-channel immediately NW of the middens and the SB ocean shoreline and associated sand barrier were located to the S and down-slope of the old landmass. Subsequent sea-level rise caused SB barrier to migrate upward and northward burying much of the pre-existing landmass and its Early to Middle Woodland sites. Also, several episodes of sand spit deposition built SB westward into paleo-Beaufort Inlet causing the inlet to migrate to its present size and location. Continued flooding expanded the width and depth of BS causing increased estuarine shoreline erosion that re-exposed the older middens and provided increased water access for Middle to Late Woodland occupation sites on the eastern portion of SB where modern coastal processes are now burying them.