http://popups.lib.uliege.be/3041-5527/index.php?id=646 Entrées d’index fr 0 http://popups.lib.uliege.be/3041-5527/index.php?id=636 The oolithic ironstones (OIS) are one of the main sources of prehistorical red dye. The geological occurrences are well known in Basse-Normandie because they were used into mining industry. The fields are often disappeared today and the samples we took are not always representative. This paper summarizes the main characteristics and the genesis of these oolithic levels. They has been deposited on a subtidal open shelf, exposed to tidal wave activity and located south of the infra-Cambrian continent. The presence of oolithic ironstone artifacts in some archeological sites is an evidence of their use as raw materials for prehistorical red ochres. To compare the geological materials and the archeological artifacts, we set up a protocol of analysis including macroscopic observations, petrography, geochemistry and color analysis. Furthermore, we integrated samples from Belgium and Germany, potentially incriminated in long-distance interchanges in Western Europe. Fri, 29 Nov 2024 13:10:40 +0100 Fri, 29 Nov 2024 14:26:18 +0100 http://popups.lib.uliege.be/3041-5527/index.php?id=636 http://popups.lib.uliege.be/3041-5527/index.php?id=650 Oolitic ironstones (OIS) disccovered at archaeological (Early Neolithic & Mesolithic) sites in the Caen region (Basse-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 Colombelles 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 Mesolithic 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 from the Plain of Caen are of local or regional origins and that Devonian (Lower Famennian, Frasnian) OIS from Belgium, Lower/Middle Devonian, OIS from the Eifel (Germany) or Mesozoic OIS from Lorraine (in the three border areas between the Grand Duchy of Luxembourg, Belgium and France) are totally lacking. Early Neolithic sites in Belgium contain no oolitic ironstone imported from Normandy. As a consequence, we can conclude that for this specific raw material, there is a lack of exchange between early Neolithic Belgian populations (Hesbaye and Dendre Springs) and the population of the Plain of Caen. Fri, 29 Nov 2024 13:21:49 +0100 Fri, 29 Nov 2024 13:21:57 +0100 http://popups.lib.uliege.be/3041-5527/index.php?id=650