Les hématites oolithiques du Néolithique ancien et du Mésolithique de Basse-Normandie (France) : caractérisation physico-chimique et recherche des provenances

International audience; Early Neolithic & Mesolithic oolitic ironstones from Basse-Normandie (France): chemical and physical characterization and provenance study ". Oolitic ironstones (OIS) disccovered at archaeological (Early Neolithic & Mesolithic) sites in the Caen region (Bas-se-Normandie, France) were analyzed and compared with Ordovician OIS sampled in geological sites in Basse-Normandie, in order to establish the source of the raw materials used in prehistory. Samples of OIS were analyzed and characterized by X-ray diffraction (whole rock and clay fraction), LA-ICP-MS, HH-XRF and PIXE. Ironstone objects from Colombelles (early Neolithic) show compositions that are different from those recovered at Biéville-Beuville (final Mesolithic). Those at Colom-belles were initially extracted from slightly weathered ironstone layers and it is suggested here that their extraction required extra digging to reach less weathered hematite-rich material. In contrast, OIS from Biéville-Beuville have a mineralogical composition indicative of more intense weathering, which might indicate collection of surface material. The final Mesoli-thic raw material of Biéville-Beuville seems to have been obtained through a different mode of acquisition than that utilized during the early Neolithic. Our research allows us to conclude that all the archaeological OIS