GEOMORPHOLOGY AT ARCHAEOLOGICAL SITE 31WK223 IN THE REDDIES RIVER DRAINAGE BASIN: AN EXAMPLE OF HOLOCENE STRATIGRAPHIC PRESERVATION ON THE BLUE RIDGE ESCARPMENT

The Reddies River drains the eastern slope of the Blue Ridge escarpment. Archaeological site 31WK223 consists of stratified Woodland to early Archaic cultural horizons with features radiocarbon dated from 1560±40 rcBP to 4770±70 rcBP. The Blue Ridge escarpment is characterized by deeply incised valleys and high gradient streams generally associated with sediment erosion and transport. Erosion resistant bedrock ridges extending into valleys can form protected coves where a record of Holocene sedimentation is preserved on alluvial terraces. Former Native American occupation surfaces were buried within three alluvial strata interpreted from differences in particle size distribution with depth in terrace alluvium. The variation in particle size between the strata could be due to changes in the location of the stream channel or differences in magnitude of flood events due to climate change. Radiometric dating of buried hearths and pit features indicate that these strata were deposited on the terrace at a rate of ~14 cm/ka between 4500 BP and 1500 BP. Deposits along the valley floor of steep gradient mountain streams are reworked during high magnitude flood events. However, these deeply incised valleys can form protective coves where a continuous stratigraphic record of Holocene sedimentation is preserved.