The detachment of Levallois flakes using bipolar percussion at Howiesons Poort Shelter, South Africa

Abstract

In the southern African archaeological sequence, the Levallois method of core reduction is considered to be a distinctive technological feature of the Middle Stone Age (MSA). Similarly, the transition from MSA to Later Stone Age (LSA) has been defined by a decline in the prevalence of Levallois and an increase in prismatic blade production and the use of bipolar percussion to reduce cores. Reanalysis of material recovered from Howiesons Poort Shelter - the eponymous site for the Howiesons Poort phase of the southern African MSA - has revealed that most of the Levallois cores from the site were knapped using a combination of freehand and bipolar percussive techniques. In these cases, freehand percussion was used to prepare and re-shape the cores, while bipolar percussion was used as a targeted strategy for detaching Levallois flakes. The discovery of this combination is significant because the accepted definition of the Levallois method prescribes the use of freehand, hard-hammer percussion only. This paper describes the trends in core morphology and reduction processes associated with this bipolar Levallois strategy and evaluates some possible motivations for using bipolar percussion to detach Levallois flakes. Analysis of core dimensions and reduction sequences suggests a gradual strategic transition between freehand Levallois and bipolar bidirectional-opposing reduction strategies as cores become smaller. Contrary to traditional depictions of the technique, bipolar percussion was used by knappers at Howiesons Poort Shelter on cores of a wide range of sizes regardless of material, particularly in situations where control over the force and location of flake removing blows was critical. As well as adding to a growing image of the technological and behavioural complexity of Howiesons Poort (and indeed MSA) hominins, these discoveries have important implications for our understanding of both the Levallois reduction method and the bipolar percussive technique.