Challenges and limits imposed by lithic raw material variability on use-wear research in the African Early Paleolithic

Abstract

The functions of the earliest stone tools, and the factors behind the first major technological changes in human behavior, are central questions in paleoanthropology, and are major issues which can be partially resolved through use wear analyses. To date, few studies have dealt with this subject, in part due to the difficulties derived from site and tool preservation issues and the low development of traces (Keeley, Toth 1981; Lemorini et al. 2014; Sahnouni et al. 2013). In addition, the broad variability of raw materials exploited at our study sites (Sahnouni et al. 2002; Santonja et al. 2014; Stout et al. 2005) and the lack of use-wear reference collections for these materials have represented major challenges for such investigations. The development of use-wear analysis as an archaeological sub-discipline is closely related to the analysis of fine-grained, crystalline rocks such as chert, flint and obsidian. Other materials (quartzite, quartz, rhyolite, trachyte, basalts, etc.) have been less intensively studied, despite important advances in recent years (e.g., Clemente Conte, Gibaja 2009; Asryan et al. 2014; Pedergnana, Ollé 2016), resulting in an neartotal lack of references concerning use-wear formation processes on these materials. To overcome these difficulties, we are building up a dedicated experimental reference collection that includes tools made of the different materials used to manufacture stone tools at Gona (Ethiopia), Aïn Hannech (Algeria) and Thiongo Korongo (Olduvai Gorge, Tanzania). This will serve to identify the wear traces left by the different activities in each rock type, thus providing reliable comparative material for our research. The initial results of this experimental program will be presented, including case studies from Gona, Ain Hanech and Thiongo Korongo.