Armenian findings provide insight into Lower to Middle Palaeolithic transition
The Middle Stone Age/Middle Palaeolithic saw a shift in emphasis from hand-axe (biface) manufacture to prepared-core methods. In the former, flakes detached from a stone core are regarded as waste products; in the latter, flakes detached from a pre-shaped stone core are the desired products. The shift to prepared-core industries probably came about as toolmakers began to recognise that debitage (waste flakes) could often be useful tools in their own right. Such methods are economical in their use of raw materials, because many flakes may be struck from the same core.
Prepared-core techniques include the Levallois method. It is named after the Parisian suburb of Levallois-Perret, where examples of prepared cores were found in the nineteenth century. The Levallois method involves at least five or six clearly separate stages, each of which requires careful preplanning. Flakes were first struck off around the periphery of a raw stone nodule; the scars from this process were then used as striking platforms (the point where a stone core is struck by a hammerstone) to remove flakes from one surface of the nodule. From the resulting core, one or more flakes could now be detached, the shape and size of which being predetermined by the core preparation. Flakes so produced were fashioned into as many as forty distinct tool types, each with its own specific cutting, scraping or piercing function. There was a much greater standardisation in the form of the tools made, indicating a clearer mental template and greater manipulative skill applied to their manufacture.
What has been unclear is whether this method was developed just once, and spread with populations, or whether it was independently invented on multiple occasions. In Africa, the Early to Middle Stone Age transition is characterised by the gradual replacement of bifaces by flakes, points, and blades produced through various prepared-core methods, principally the Levallois method. On the single-invention picture, such a gradual transition would not be seen elsewhere; rather there would be a discontinuity as human groups dumped their outmoded Acheulean hand-axes and adopted the new technology.
However, recent findings from the site of Nor Geghi 1, Armenia (NG1) suggest that this was not the case. A mixture of Acheulean and Levallois artefacts have been recovered, 316 in all, made from locally-available obsidian. The artefacts are around 300,000 years old and are the earliest examples of this technology to be found outside of Africa.
The findings support the hypothesis that Levallois technology arose gradually from Acheulean technology on multiple occasions and its presence in Africa and Eurasia represents technological convergence rather than a ‘technical breakthrough’ that spread from a single point of origin.
- Adler, D. et al., Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus. Science 345 (6204), 1609-1612 (2014).