Pigment mixtures, pictorial recipes and stories: A physicochemical approach to the social practices of painting on Oyola Hill (Catamarca, Argentina)

This article aims to advance the understanding of the historical painting process at the archaeological site of Oyola (Sierra El Alto-Ancasti, Catamarca, Argentina). In particular, it intends to evaluate similarities and differences in the material composition of the pigmentary mixtures to glimpse the existence of ancient pictorial recipes. Microstratigraphic analyses of 28 black motifs were performed by scanning electron microscopy with elemental analysis by energy-dispersive X-ray spectroscopy (SEM-EDS) and micro-Raman spectroscopy (RS). The comparative study of these results pointed to the alternative use of two black pigments (charcoal and manganese oxides), combined, in some cases, with calcium sulfate. In this way it was possible to acknowledge certain aspects of the pictorial recipes that oriented the preparation of the black pigment mixtures, approaching some of the traditions and knowledge reclaimed. In order to understand these recipes in relation to the history of the site, the spatial dispersion, chronology, and some formal characteristics of the rock art motifs executed with them were evaluated. Since no clear trends were identified, a less normative definition of pictorial recipe is proposed, highlighting the shared aspects between painting episodes, without losing sight of the creative possibilities of each event.