Processus et milieux du traitement thermique des silex barrémo-bédouliens au Chasséen (fin 5ème et 4ème mill. Cal BC , Méditerranée occidentale) – ProMiTraSil

At the end of the fifth millennium (Cal. BC), an important change occurs in the evolution of the Neolithic societies from the north western Mediterranean. Profound socio-economic changes are reflected by two related phenomena : a more pronounced craft specialization and the development of long-distance trade. In archaeological terms, this is particularly visible in the southern Chassey culture stretching across the south of France. It is in this context that we see the exceptional dissemination of specialized lithic productions made in barremo-bedoulian flint from the Vaucluse. The magnitude of these exchange networks is measured on a European scale since products from the Vaucluse are exported to Italy and Catalonia. How then to explain the extent of dissemination of Vaucluse productions' What prompted these Neolithic communities of the north-western Mediterranean to adopt the same tools, and for over 700 years' What in the manufacturing process justifies the high exchange value of these goods' These questions will be addressed through the analysis of the particular production of the southern Chassey culture : it is characterized by heat treatment of the barremo-bedoulian flint so as to obtain thin bladelets by pressure. The segmentation of the production of bladelets, in time and space, is linked to different expertise: the very delicate phases of formatting the pre-cores (performs or future cores for bladelets) take pace on the producer sites in the Vaucluse and are performed by specialists, while on the consumer sites, the debitage of bladelets belongs to the domestic tasks that do not require the same skills. On one hand, on producing sites, the flint heat treatment is at the least a complex operation: creating an environment for heating, gradual increase of temperature, maintaining the temperature for a given time, gradual decline of temperature. On the other hand, on the consumer sites, the heat treatment facilitates the knapping of bladelets: detaching the bladelets would be easier due to lesser pressure needed (experiments by J. Pelegrin to continue). The heating, essential and inevitable step in the chaîne opératoire for bladelets, is one of the fundamental keys for understanding this system in which producers and consumers are totally interdependent. The heating process thus illustrates the social division of labor between producers who know how to put in form and consumers who do not know. Today we know very few on the heating of barrémo-bédoulian flint. What are the heating processes and environments that make these transformations possible' As far as the context of our study is concerned, this issue is particularly important because, unlike what is known in other chrono-cultural contexts where there is heating for retouching tools (and not debitage), the heated modules are very large as is shown by recently found preforms on different producer workshops. However, a large volume of flint poses many problems for heating as it increases the risks of fracturing. This project seeks a better understanding of the conditions necessary to make the heating a success. To this end, several approaches must be conducted in parallel : - Archaeological approach: expert study in particular of failed heated flints found on the producer sites. - Physical approach: what physical transformations have the barrémo-bédoulien flints undergone that can explain the observed changes' What happens at the atom scale' - Chemical approach: analysis of residues found on the manufacturing waste from the preforms of St. Martin in order to obtain indications about the heating environment. - Experimental approach: 1 / carry out heat treatments on reproductions of Chassey culture preforms in an oven in order to identify the range of temperatures in which barrémo-bédoulien flints undergo changes. 2 / assessing the effects of heat treatment on barrémo-bédoulien flints for the debitage of bladelets by pressure. The issues of this project are important for the apprehension of these Neolithic societies. To take up the study of these barrémo-bédoulien flint industries and in particular the issue of heating, is to address the skills of the specialized craftsmen. The results of this project are awaited on European and international levels. Our European colleagues, especially Italian and Spanish, are particularly interested, as quite a number of their archaeological sites were fed by these diffusion networks of heated barremo-bédoulien flint. On an international level, the results of this project will undoubtedly open interesting avenues of research for the study of other chrono-cultural contexts in which there are indications of the heating of different flints.