Micro‐Raman spectroscopy for the analysis of materials found in rock art shelters in Piedra Parada valley, Chubut province, Argentinian Patagonia

Micro‐Raman spectroscopy was employed for the analysis of samples collected from the shelters Campo Cerda 1, Angostura Blanca and Campo Moncada 1 located in Piedra Parada valley, Chubut province, Argentinian Patagonia. Different coloured layers, degradation products and rock supports were analysed. Haematite (α‐Fe2O3), goethite (α‐FeOOH), green earth and gypsum (CaSO4 ·2H2O) were responsible for the main colouration of the pigmented layers together with other components. Gypsum, Ca‐oxalates and calcite were the major degradation materials affecting the rock paintings and the rock support. Different types of silicates, apatite [Ca5(PO4)3(F,Cl,OH)] and goethite were positively characterized in the rock support. Point analysis and micro‐Raman mappings contributed towards a better understanding of the materials and layer sequencing of the samples extracted. The current research demonstrates the analysis of samples extracted, in 1995 and 1996, from the shelter Campo Cerda 1, Angostura Blanca, Campo Moncada 1 located in Piedra Parada valley, Chubut province, Patagonian Argentina. A thorough micro‐Raman investigation was performed regarding the pigments used, the white crusts and rock support. Micro‐Raman mappings revealed the layers' sequencing of pigmented cross section and surface scrapings collected from the ancient open air rock shelters.