Arqueometria e o sítio arqueológico Pedra do Cantagalo I: uma estratégia de investigação como modelo para a América do Sul

Abstract

A Pedra do Cantagalo I é um sítio arqueológico localizado na área rural do município de Piripiri, estado do Piauí, Brasil. Consiste em um abrigo sob-rocha arenítica, cujas saliências e reentrâncias estão decoradas com mais de 1.950 pinturas rupestres representando figuras abstratas, propulsores de dardos, carimbos de mãos humanas, antropomorfos e zoomorfos, realizados em padrões policromáticos. Além da elevada densidade de inscrições pré-históricas e da policromia, esse sítio também se destaca pela recorrência dos motivos pintados e pela sobreposição deles entre si. Nos sedimentos superficiais foram encontrados fragmentos cerâmicos, líticos e ocres. Carvões residuais encontrados em fogueiras bem estruturadas, evidenciadas em recentes escavações neste abrigo, foram datados pelo método do 14C como sendo de 1.180 ± 30 anos antes do presente; em estratigrafia também foram evidenciados materiais cerâmicos, líticos e ocres vermelhos e amarelos. Neste artigo são reportadas as estratégias analíticas de campo e de laboratório utilizadas na investigação desse importante sítio arqueológico e dos testemunhos de atividade humana pré-histórica nele existentes ou dele coletados. Os exames físicos, a caracterização químico-mineralógica dos materiais, o monitoramento das condições ambientais e as prospecções no entorno foram primordiais. Abstract: Pedra do Cantagalo I is an archaeological site located in the rural area of the municipality of Piripiri, Piauí state, Brazil. It consists of a sandstone shelter decorated with more than 1,950 rupestrian paintings representing abstract figures, spear-throwers, human handprints, and anthropomorphic and zoomorphic figures in polychromatic patterns. In addition to the high density of prehistoric inscriptions and polychrome paintings, this site also stands out due to the recurrence of painted motifs and to the overlapping of the paintings. Ceramic materials, lithics, and ochres were found in the sediments. Residual charcoals found in remnants of well-structured hearths, as recently evidenced from excavations in this shelter were AMS (accelerator mass spectrometry) 14C-dated as being from 1,180 ± 30 years before present; in stratigraphy, ceramic materials, lithics, and red and yellow ochres were also evidenced. In this paper, the field and laboratory analytical strategies used in the investigation of this important archaeological site are reports as well as the evidence of prehistoric human activity contained within or collected from the site. The investigative techniques included physical examinations of the site, chemical-mineralogical characterization of the materials, monitoring of the environmental conditions and prospections in nearby areas.

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

“…Rupestrian engravings (some were painted), chipped lithics, polished lithics, ceramic fragments and mineral pigments in the form of red and yellow ochres also were found [13][14][15] (Figure 3). 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].…”