Pierluigi Rosina

Dating and Raman spectroscopy of rock art paintings in Ebo, Angola

ABSTRACT The Ndalambiri rock shelter in the Ebo region of Angola is a key site for assessing human occupation there given its potential association between stratigraphic contexts and rock art panels. Focusing on the Iron Age and European contact periods, this study characterised the site’s rock paintings using Raman spectroscopy, while also obtaining AMS radiocarbon dates from paint residues and charcoal collected in stratigraphic context during a trial excavation below one of the painted panels. Raman spectroscopy results revealed the use of a carbon-based pigment (charcoal?), haematite and calcite to prepare black, red and white paints respectively. AMS dating of a black paint sample showed that it was produced between the seventeenth and the twentieth centuries, corresponding to the last known phase of rock art production in the area, as further indicated by its stratigraphic position and the depiction of firearms at the site. Earlier occupation of the site associated with metallurgical activity was dated to the mid-first millennium AD and may suggest that the oldest rock art at Ndalambiri corresponds to the arrival of metal-using populations in the region.

Quartzite pebble technology in the final Middle Pleistocene of the Ribeira da Ponte da Pedra site (High Ribatejo, Central Portugal)

The lithic assemblage of Ribeira da Ponte da Pedra site (OIS8-9) was produced, almost exclusively, through the exploitation of good quality quartzite fluvial pebbles with a regular morphology. Quartzite fluvial pebbles are the most common raw material found in the Middle Pleistocene occupation sites in Portugal. Such feature results from the easy availability of these pebbles in the valleys where the great majority of the archaeological sites within this chronology are located, and also because of the quartzite’s physical properties and suitability for knapping. In a techno-typological point of view, its lithic assemblage is characterized by the application of two main reduction sequences that result in abundant worked pebbles, retouched pebbles, cortical and semi-cortical flakes, retouched flakes, a few cores and rare bifacial artefacts. Some artefacts present irregular and variable edge modifications described as ‘atypical’ edge modifications that could edge damage resultant from their utilization. From a strictly technical point of view the assemblage can be described as quite simple, however we can envisage an inherent complexity starting in an accurate selection and exploitation of the quartzite pebbles, whose regular morphology allows a ‘predetermined’ production of regular blanks through simple actions. In order to better understand patterns of raw material selection and technical schemes adopted in the exploitation of the quartzite pebbles we compared a sample of pebbles collected in the same deposits identified in the site (t4 fluvial terrace deposits) with worked pebbles that have 1 or 2 removals that had not altered significantly the original morpho-volumetry of the pebbles. The goal of this comparison was to verify if there was a selection of the fluvial pebbles based on texture and morpho-volumetry and if so, relate such selection with the technical schemes identified by technological study of the assemblage.

Pré-história na foz do rio Chapecó

O alto rio Uruguai e uma area importante para compreender o povoamento pre-historico da bacia do rio da Prata. Nela foram localizados sitios de cacadores-coletores, referentes ao passado mais antigo da regiao, e de grupos ceramistas relacionados as unidades arqueologicas Tupiguarani e Taquara-Itarare. Este artigo apresenta os primeiros resultados das pesquisas realizadas no sitio ACH-LP-07 situado proximo a foz do rio Chapeco na margem direita do rio Uruguai, no oeste de Santa Catarina. O mesmo apresentou varias ocupacoes por cacadores-coletores no inicio do Holoceno, caracterizadas por uma variabilidade nas producoes de pedra lascada, onde se destaca a producao de lâminas por uma debitagem especifica. No ultimo milenio o local tambem foi povoado por grupos ceramistas Guarani. O sitio tem trazido diferentes contribuicoes a respeito dessas antigas sociedades, especialmente as modalidades de ocupacao e de sucessao dos grupos humanos no alto rio Uruguai.

Archaeometry of rock art paintings: La Piedra De La Cuadricula (Soacha, Cundinamarca, Colombia). A contribution to the study of prehistoric art

This article is a part of the results of the master thesis, which aim was to improve significantly the studies of the conditions of pictorial elements in a rock art mural, that is, to know the materials that were used and their interactions with the open air. This academic exercise introduces new aspects in the research process concerning the materials present in these rock art works and leads up to the works about technology of pigments in the studied area, extending the descriptive possibilities of the conservation conditions of rock art. The study of the materials opens a route towards the conservation work, and constitutes an essential way for the projected studies on dating. In this work, pigments were analyzed, some accretions, the rock substrate and the possible raw material of the rock art paintings. This analysis was done using Spectrometry Infrared. This investigation process is set in the context that the research group GIPRI has developed, as an extension of the methodological model of record and documentation of rock art in Colombia, especially in the cundiboyacense highplateau. The rock chosen was “La Piedra de La Cuadricula “, located in a set of 167 rocks in Tequendama’s area, Soacha’s Municipality, in Cundinamarca’s department. This sector is one of the most important archaeological sites of the country. In this site cultural stratigraphic sequences between 12 500 B.P. and 2500 B.P. have been found. On the other hand, there have been developed very important studies of the Pleistocenic and Holocenic environment.