DOI: https://doi.org/10.5281/zenodo.1315016.

Abstract. The archaeological site known as Tamboril, located in the rural area of the municipality of Barras, Piauí State, Brazil, is a sandstone block that contains a niche decorated with rock paintings. These paintings are mainly composed of pure graphisms, zoomorphic motifs, and human handprints, painted in different tonalities of red. Their conservation has been affected by saline efflorescences, residues of insect activities (such as wasps and termites) and human impact (unguided visitors and nearby agricultural activity). The archaeometric analysis of pigments from these rock paintings was performed in the laboratory with energy dispersive X-ray fluorescence and room temperature ⁵⁷Fe Mössbauer spectroscopy in backscattering geometry of γ-rays. The contents of Fe (as Fe₂O₃) ranged from 2.953(1) mass% to 17.23(1) mass%. The hyperfine Mössbauer parameters revealed that the dark red pigment from the rock paintings is composed of hematite (αFe₂O₃) and a (super)paramagnetic Fe³⁺. The contents of P (as P₂0₅) ranged from 21.70(1) mass% to 25.92(1) mass% and were attributed to saline efflorescences and residues of insect activities that cover the prehistoric inscriptions.

Keywords: Rock paintings, Mössbauer spectroscopy, Archaeometry, Tamboril, Barras.

Reference:

Duarte Cavalcante, L. C., S. M. Campelo Magalhães, E. Lurrik Sousa da Silva, H. K. Sousa Bezerra da Silva. 2016. Análise arqueométrica de pinturas rupestres pré-históricas do sítio Tamboril, Barras, Piauí, Brasil. Arqueología Iberoamericana 29: 44-49.
URL: http://laiesken.net/arqueologia/archivo/2016/29/7. PURL: http://purl.org/aia/297.

Publication date: 3 March 2016.