The Role of Thermal Alteration in Lithic Reduction Strategies at the Leftwich Site in Middle Tennessee

Research in 1978, 1980 and 1981 at the Leftwich site (40MU262), located on the Duck River in Maury County, Tennessee revealed stratigraphically separated buried Archaic cultural strata. Radiocarbon dates of 6160 and 4190 to 4130 years before present were associated with Benton and Ledbetter projectile points, respectively. A functional analysis of artifacts from a controlled surface collection and two buried Archaic components at Leftwich is undertaken. Buried Benton and Ledbetter components were stratigraphically separated based on vertical density peaks of lithic artifacts and debitage, as well as pebbles larger than 6 mm in size. The relationship of thermal alteration to lithic resource location, lithic implement manufacturing processes and settlement is investigated. Intentional thermal alteration of lithic artifacts is indicated by: (1) an overall low incidence of overheating and (2) an association between thermal alteration and small biface thinning flakes and late stage bifaces in the surface, Benton and Ledbetter assemblages. Intentional thermal alteration is also significantly correlated with cores and large biface thinning flakes. Thermal alteration analysis can yield information regarding when and where lithic reduction took place