Análise Químico-Mineralógica De Ocres E a Busca Por Correlações Arqueológicas Com Os Pigmentos De Pinturas Rupestres Do Sítio Pedra Do Cantagalo I

Abstract

Este trabalho foi devotado à análise arqueométrica de ocres vermelhos e amarelos do sítio arqueológico Pedra do Cantagalo I, Piripiri, Piauí. Prospecções foram efetuadas nas proximidades do abrigo rochoso, no interesse particular de se identificar jazidas fontes dos pigmentos minerais das pinturas rupestres. A composição químico-mineralógica dos ocres foi correlacionada com os dados correspondentes aos dos materiais minerais oriundos das jazidas do entorno e das camadas de tintas das pinturas rupestres das superfícies areníticas decoradas do sítio. Os resultados obtidos mostram evidências de que os ocres fontes dos pigmentos das pinturas rupestres foram originalmente enriquecidos, na preparação arqueológica, por concentração das espécies oxídicas ferruginosas e aluminosas, às expensas da redução quantitativa dos minerais silicatados, do material precursor diretamente retirado das jazidas.CHEMICAL-MINERALOGICAL ANALYSIS OF OCHRES AND THE SEARCH FOR ARCHAEOLOGICAL CORRELATIONS WITH THE PIGMENTS OF RUPESTRIAN PAINTINGS OF THE SITE PEDRA DO CANTAGALO IABSTRACTThis archaeometric work was devoted to the chemical-mineralogical characterization of red and yellow ochres of the archaeological site Pedra do Cantagalo I, Piripiri, Piauí. Field surveys were made in the neighboring of the rocky shelter, seeking for any apparent evidence signalizing the mineral source of such mineral pigments. The chemicalmineralogical composition of the ochres was correlated with corresponding data obtained from analyzing the nature of the minerals from the surrounding deposits and from the paint layers of the rupestrian paintings on the decorated sandstone surfaces of this archaeological site. The results for the ochres fairly show clear evidence that the ferruginous phases, as well as aluminum-containing minerals, were prepared for the enrichment in iron oxides, apparently at the expense of the removal of silicate minerals, from the material withdrawn from the deposits.Keywords: Ochres; Mössbauer spectroscopy; Archaeometry.

Rupestrian Paintings from the Archaeological Area of Piripiri, Piauí, Brazil: A Current Overview

“…Residual charcoals found in well-structured hearths, as recently evidenced from excavations in this rocky shelter, were 14 C-dated using accelerator mass spectrometry (AMS) as being from 1,180 ± 30 years before present (BP; calibrated result at 95% probability, 2σ, from 1,070 to 960 years cal BP; Beta-420913) [16,17]. Samples containing thin layers of paint from rupestrian paintings of different colors, as well as red and yellow ochres, ceramic fragments, palaeosediments and saline efflorescences samples collected in this archaeological site were investigated by energy dispersive X-ray fluorescence, CHN elemental analysis, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, 57 Fe-Mössbauer spectroscopy, Raman spectroscopy, grazing incidence X-ray diffraction, powder X-ray diffraction and magnetization measurements using vibrating sample magnetometer, in an effort to assess the chemical and mineralogical characteristics of these materials [14,[16][17][18][19][20][21].…”

“…The archaeometry has been used as an important tool for the analysis of several types of ancient materials of archaeological sites from Piauí and the 57 Fe Mössbauer spectroscopy has been used as a non-destructive nuclear technique and decisively fundamental on the chemical-mineralogical characterization of ferruginous species of these materials [10,14,16,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”