AFRICAN HOMO-ERECTUS - OLD RADIOMETRIC AGES AND YOUNG OLDOWAN ASSEMBLAGES IN THE MIDDLE-AWASH VALLEY, ETHIOPIA

Fossils and artifacts recovered from the middle Awash Valley of Ethiop ia's Afar depression sample the Middle Pleistocene transition from Hom e erectus to Home sapiens. Ar/Ar ages, biostratigraphy, and tephrachro nology from this area indicate that the Pleistocene Bodo hominid crani um and newer specimens are approximately 0.6 million years old. Only O ldowan chopper and flake assemblages are present in the lower stratigr aphic units, but Acheulean bifacial artifacts are consistently prevale nt and widespread in directly overlying deposits. This technological t ransition is related to a shift in sedimentary regime, supporting the hypothesis that Middle Pleistocene Oldowan assemblages represent a beh avioral facies of the Acheulean industrial complex.