Characterization and origin of black and red Magdalenian pigments from Grottes de la Garenne (Vallée moyenne de la Creuse-France): a mineralogical and geochemical approach of the study of prehistorical paintings

Pigments sampled from wall paintings and from crayons taken on the floor, at the Grottes de la Garenne (Saint-Marcel – Indre, France) have been analyzed and characterized by infrared spectroscopy, Raman micro-spectroscopy, X-ray diffraction, ICP/MS and analytical TEM. The red pigment used for the wall paintings is mainly composed by hematite, clays, carbon matter and carbonates. Results on the red pigments show that the compositions of the paintings are similar to that of some crayons. Regarding these analyses, their origin is compatible with local siderolithic facieses. Analysis of black pigments shows that they are made of cryptomelane, pyrolusite, clays, carbonates and carbon matter. It shows also that paintings and some crayons compositions are compatible. On the contrary of red pigments, the origin of black pigments is probably allochtonous. Indeed, the traces of thallium detected in cryptomelane, the cerium anomaly and the absence of iron are not compatible with local facieses or other sites from the French Massif Central.