Dates for the Middle Stone Age of East Africa

Abstract

Three potassium-argon age determinations on sanidine from crystalrich pantellerite and volcanic ash in the Main Rift Valley of central Ethiopia indicate that the Middle Stone Age of East Africa began prior to 180,000 years ago. This suggests that the technological developments which characterize the Middle Stone Age have a far greater antiquity than previously estimated.

Levallois Lithic Technology from the Kapthurin Formation, Kenya: Acheulian Origin and Middle Stone Age Diversity

“…The sites at Nazlet Khater, Egypt, where Van Peer (1992 describes preferential Levallois flakes struck from centripetally prepared cores as well as point production from specialized Nubian Levallois cores, are dated to the Late Pleistocene on geomorphological grounds. A greater age is indicated for MSA sites at Gademotta near Lake Ziway, Ethiopia, where prior K/Ar age estimates of >180 ka have been revised to >235 ka (Wendorf and Schild, 1974;Wendorf et al, 1975Wendorf et al, , 1994. Multiple Levallois approaches for flake and point production are likely present at site ETH-8-B at Gademotta, although this assemblage requires reanalysis in light of recent ideas concerning the nature of Levallois technology.…”

Tensional fissures and crustal extension rates in the northern part of the Main Ethiopian Rift

“…Middle Stone Age artefacts fashioned from locally derived obsidian are concentrated within the Lower and Middle Vertisols. Similar Middle Stone Age assemblages are dated elsewhere in Ethiopia and Kenya as c.250,000-c.45,000 BP (Wendorf et al, 1975;Clark, 1988 (Williams et al, 1977).…”

Possible isotopic fractionation of argon in source obsidians and archeological artifacts from Kulkuletti, Ethiopia

“…The artifactual samples are thirteen pieces of obsidian debitage from an MSA excavation area (Kulkuletti, K-Ar dated at 181-149 ka by Wendorf et al (1975); or 191-157 ka using new constants) located west of Lake Ziway in central Ethiopia, about 100 km south of Addis Ababa (Fig. 1).…”

“…Wendorf et al (1975) placed the sites temporally at w0.16 Ma, but recent work has shown that the sites are 0.28 Ma and younger (Morgan and Renne, 2008). Materials analyzed for argon content were small fragments of obsidian selected from the 0.5-1 mm fraction under a binocular microscope, avoiding fragments with pyroxene, gas bubbles or devitrified glass.…”