The Grain de mil flint, a key resource from south-western France during the Palaeolithic: Characterization and determination criteria in archeological contexts

Land use patterns are typically used to describe Palaeolithic hunter-gatherer nomadic groups. Due to the methodological development of petroarchaeology, in south-western France in particular, this region is one of the best documented European areas in terms of siliceous resources. But one major unknown still needs to be addressed: the characterization and origin of the so-called “Grain de mil” flint, a common raw material that has never been properly described and sourced even though it has been identified in archeological contexts over a very extensive area. In order to address this issue, we first approach the question of the lithic raw material analytical method: the sedimentary petrographic description remains the best approach to directly include petrological data in a petro-techno-economical study. We then present the results of the Grain de mil study: this material is typical of Charente-Maritime as its formation is linked to the Jonzac anticline. It forms a flint group comprising two types (Jonzac and Saintes), mostly differing with regard to outcrop location, and nodule size and shape. In archeological contexts, criteria observable with a binocular microscope are sufficient to distinguish the Grain de mil from other north Aquitaine Cretaceous materials with abundant grains, particularly regarding their organization and pattern, and the absence of quartz grains