Middle Stone Age at Equatorial Guinea: Technical and use-wear analysis of lithic bifacial points

Abstract

Lithic industries during the Upper Pleistocene in Equatorial Guinea may be broadly included in the Central African Middle Stone Age (MSA) Lupemban tradition. However, these industries present certain particularities related to their raw materials, and stone-knapping sequences. In the case of bifacial tools, bifacial points are commonly found with a cortical reserved proximal portion that keeps the cortex covering the base and part of both faces. Bifacial points made on thin stone slabs that keep the cortex on the center of one or both faces are also commonly found. This knapping technique gives the idea of unfinished preform artifacts. The edges, however, suggest that both points and other bifacial artifacts were used for some tasks. A sample of these tools was taken from the open-air Mabewele I site to decide whether the MSA points from Equatorial Guinea were finished artifacts, in spite of the preservation of their cortex. Petrographic studies and macro and microscopic analyses of the use-wear traces and residues from retouched edges were also performed. The analysis clearly shows that the Mabewele I bifacial artifacts were used for plant processing, among other activities. The results confirmed the fact that cortical reserved-base points with cortex on one or both faces were intentionally manufactured, finished tools, rather than unfinished preforms. The petrographic analysis also shows the schistous nature of raw material and explains the shape and stepped edges of bifacial knives, extending our understanding of the unique technical characteristics of the MSA in Equatorial Guinea. It also provides new insights into some of the hunter-gatherer's subsistence strategies in the Central African tropical rainforest at the end of the Pleistocene.