http://popups.lib.uliege.be/3041-5527/index.php?id=643 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