NEW 40AR/39AR AGE CONSTRAINTS FOR MIDDLE STONE AGE ARCHAEOLOGY AT GADEMOTTA AND KULKULETTI, ETHIOPIA
Here we present new age constraints on archaeologically rich sediments containing MSA technology at Gademotta and Kulkuletti, near Lake Ziway in the northern part of the Main Ethiopian Rift. Abundant artifacts, made exclusively from locally-derived obsidian, are found in-situ in sedimentary context. Single-crystal total-fusion 40Ar/39Ar data indicate two tuffaceous horizons, which bound most of the archaeology at Kulkuletti, are 193 +/- 5 ka (Unit D of Laury and Albritton, 1975) and 298 +/- 11 ka (Unit 10 of same paper). Additional single-crystal, step-heating analyses (in progress) from the lower tuff, which can be traced physically and geochemically to Gademotta, should further constrain the older age. These new ages are significantly older than previous K/Ar work (149 +/- 13 ka and 181 +/- 6 ka, respectively) (Wendorf et al., 1975) and place Gademotta and Kulkuletti among the earliest well-dated MSA sites.