Les bifaces : des outils polyfonctionnels ? Étude tracéologique intégrée de bifaces du Paléolithique moyen récent du Sud-Ouest de la France

摘要

Handaxes are often seen as polyfunctional tools, or the “ Swiss Army Knife” of Prehistory, because of their morphological characteristics, especially the angle of their cutting edges. In fact, we know very little about the technical function of handaxes. Indeed, few functional studies have been conducted on handaxes, while many studies have examined the morphology, methods and techniques of production and reduction of these artefacts. To interpret the bifacial industries, we need to have more functional data, and thus to conduct further use-wear analysis. The functional results should be confronted with the techno-morphological data, since the technological features, the morphology and the way of using handaxes were certainly closely related. In this paper, we study some Mousterian of Acheulean Tradition (MTA) handaxes from several sites in South-West France : Chez-Pinaud (Jonzac, Charente-Maritime), and Fonseigner, Combe Brune 2, La Graulet and La Conne de Bergerac (Dordogne). We describe their morphology and their technological features, in particular through diacritic diagrams. Several morphological patterns appear for handaxes, depending at least partially on their reduction state. For the handaxes from Jonzac, we show that there was a strong link between their morphology and their reduction state. On this site, Neanderthals produced handaxes with regular convergent edges and a cutting tip. They resharpened these tools until their edges and/ or their tip became irregular and blunt, and then they changed the handaxes’ morphology radically by irregular and abrupt removals or notches (denaturation or recycling). At La Graulet and La Conne de Bergerac, handaxes often have a distal transverse edge ; this morphology seems to have been deliberately sought as it was not the result of the reduction process. Use-wear analyses were also conducted at both low and high magnification. Use-wear traces were interpreted thanks to comparisons with the experimental traces from a frame of reference that we defined for this study and which represents about 100 active areas. Several knappers produced experimental handaxes that we used in different ways for various activities : mainly butchery, woodworking and hide treatment. The study of the experimental tools showed that macro-traces, especially edge removals, occur frequently and can be used to determine the direction of motion and the hardness of the material worked, in the same was as on unretouched edges. The use-wear analysis of MTA handaxes demonstrated that they were used in different ways, but the traces mostly indicated a cutting motion on soft materials during butchery. By combining functional, morphological and technological data, a link appeared between the way of use, the morphology and the reduction state of the handaxes. Handaxes with converging edges, which are the most frequent, were originally manufactured to be used as butchery knives. The handaxes with a transverse distal edge are rarer and were used to chop some medium hard materials such as wood. These data, the functional interpretations of the sites analysed and the assumed mode of mobility for the MTA may indicate that these tasks were carried out during the displacements necessary to acquire animal and plant materials. Subsequently, the reduced or denatured handaxes were probably reused in base camps for other activities such as hammering, because their morphological features no longer allowed them to be used for their initial tasks.