Hidden paintings, forgotten histories: a micro-stratigraphic approach to study coated rock art

Abstract

Is it possible to detect rock paintings coated by natural or anthropic concretions? In this work, a methodology to discover and characterize underlying paintings is proposed. This approach combines chemical studies by micro-Raman and SEM-EDS of micro-stratigraphic samples taken from the paintings and support rock. As a case of study, it is described the research performed in the archeological site of Oyola in the northwest of Argentina. Strong evidences of red, black, and white hidden paintings have been found. In addition, the method herein presented is thoroughly evaluated pointing out their possibilities and limitations as a tool for the understanding of the historical processes involving production and transformation of the rock art panels. To this end, the methodology was proofed to be a successful exploratory approach for painting detection, expanding its capabilities when complemented with non-invasive characterization techniques.

Looking for Painting Mixtures to Glimpse Pictorial Techniques: A Micro-Stratigraphic Physicochemical Approach to the Rock Art From the Oyola’s Caves (Argentina)

“…The method used for the micro-stratigraphic analyses involves a sequence of stages before, during and after sampling, the detailed information can be found elsewhere [17,41]. Briefly, the samples (of about 1 mm 2 ) were taken using a scalpel and binocular lenses (OptiVISOR, Donegan Optical Company, USA) for deeper precision, being afterwards stored in 1.5-mL-capacity Eppendorf tubes.…”

“…Recovering the hypothesis of a wide chronology of the site's paintings, we focus the studies on the application of different lines of evidence in order to approach the histories of production and transformation of rock art panels. In this way, we have performed stratigraphic excavations of the caves [50], stylistic studies of paintings [51], analysis of overlapping figures [52], spatial studies of the places selected to do the paints [51] and chemical analysis of micro-samples taken from paintings [5,17,41]. By the development of strategies to link all these evidences [53], the research group was able to reach a more complex understanding of the site's history.…”

“…These results, we think, will improve the understanding of the technical heterogeneity and temporal complexity of painting sets in Oyola and could be a useful methodological alternative to apply in other sites. Finally, it must be highlighted that the studies herein presented are not the result of a single case or sample but the product of a large number of samples analyzed throughout the archeological site of Oyola for the last 7 years [5,17,31,41].…”

Looking for Paint Mixtures to Glimpse Pictorial Techniques: A Micro -Stratigraphic Physicochemical Approach to the Rock Art From the Oyola’s Caves (Argentina)

“…The method used for the micro-stratigraphic analyses involves a sequence of stages before, during and after sampling, the detailed information can be found elsewhere [12,42]. Brie y, the samples (of about 1 mm 2 ) were taken using a scalpel and binocular lenses (OptiVISOR, Donegan Optical Company, USA) for deeper precision, being afterwards stored in 1.5-mL-capacity Eppendorf tubes.…”

“…In this context, the hypothesis of a wider chronology is considered, focusing our studies on the application of different lines of evidence to approach the histories of production and transformation of rock art panels. In this way, we have performed stratigraphic excavations of the caves [51], stylistic studies of paintings [52], analysis of overlapping gures [53], spatial studies of the places selected to do the paints [52] and chemical analysis of micro-samples taken from paintings [12,18,42]. By the development of strategies to link all these evidences [18], the research group was able to reach a more complex understanding of the site's history, with paintings attributed to La Aguada culture but others linked with prior and later occupation periods.…”