DR. PAOLA VILLA, University of Colorado Museum, Boulder, Colorado, received a grant in October 2008, to aid research on 'Experimental Replication and Functional Analysis of Still Bay Points from Blombos Cave (South Africa).' The main goal of the project was to understand the level of skill in manufacture and use of bifacial points recovered from the Middle Stone Age (c. 75 ka) Still Bay levels at Blombos Cave in South Africa. Experimental knapping and detailed observation of the technical features of the Blombos and experimental points and flakes, using a Leica Multifocus microscope, showed that the Blombos craftsmen used the pressure flaking technique during the final shaping of points made on heat-treated silcrete. Pressure flaking is a technique used by prehistoric knappers to shape stone artifacts by exerting a pressure with a pointed tool near the edge of a worked piece. Application of this innovative technique allowed for a high degree of control during the detachment of individual flakes resulting in thinner, narrower and sharper tips on bifacial points. The earliest previously recorded evidence of pressure flaking comes from the c. 20 ka Solutrean industry of Western Europe. The evidence from Blombos is 55 ka earlier. This is a very significant find. Bifacial technology based on intensive thinning and pressure retouch was a major innovation which allowed Still Bay craftsmen to produce thin and regular foliate points to be used as more effective spear heads for hunting. This technology may have been first invented and used sporadically in Africa before its later widespread adoption in other continents. The result of this work has been published in Science.
Mourre, Vincent, Paola Villa, Christopher S. Henshilwood, 2010. Early Use of Pressure Flaking on Lithic Artifacts at Blombos Cave, South Africa. Science 339: 659-662.