The Urgonian chert from Provence (France): the intra-formation variability and its exploitation in petro-archeological investigations

International audienceUnderstanding details of stone tool procurement and transfers is for a major research avenue in improving our knowledge about prehistoric societies. The accuracy of the provisioning sources identifications is based on the establishment of large regional repositories. Recent studies show that specific investigations on the evolution of cherts were effective in distinguishing primary sources from the various secondary sources of a raw material. In this paper, we focus on another difficulty that is the distinction between different primary sources of the same geological layers. We consider the specific case of the Bedoulian cherts from southeastern France. This chert was exploited and circulated over large distances during the whole prehistoric record. It is particularly known to have been heat-treated during Late Chassey culture (Neolithic). We show in this paper that paleogeographical variability exists due to variations in the bioclastic and detrital components. With the support of foraminifera data, the granulometry of detrital quartz grain provides the possibility to distinguish between different primary sources. A first test in archeological contexts illustrates the efficiency of the method as well as indicates major changes in provisioning practices between upper Paleolithic and Neolithic groups