Raw material diversity, availability and sourcing in the River Lis basin, Central Portugal (original) (raw)

The project EcoPLis––Human Occupations in the Pleistocene Ecotones of the River Lis––started in central Portugal in 2015. It aims to understand the behavioural ecology of hominins during the Pleistocene in a region where sub-rectilinear rivers link the coast to the inland mountains through open riverine and canyon environments. This project is rooted in Leiria’s mapping project––CARQLEI––managed by the City Council that has been mapping archaeological sites and off-sites since 2004, including some identified by Cultural Resource Management projects. One of the most important aims of EcoPLis is the systematic recording and spatial analysis of raw material sources. The Lis basin has a large diversity of rocks suitable for knapping and multiple sources of these materials can be found both in primary and secondary sources. Although rocks are readily available, some materials were selectively sourced and used in the production of stone tools, e.g. chert, quartzite and quartz. The last two are allochthonous, showing great diversity and are highly abundant in river and marine gravels. On the other hand, chert is autochthonous, and it can thus be obtained from secondary and subprimary positions, and extracted from primary outcrops that are considerably limited in space, such as those of the Ribeira das Chitas valley. In this paper we present a tentative map of raw material types and availability in the Lis basin and a preliminary geochemical analysis of chert specimens collected in primary, sub-primary and secondary positions. Our goal is to set a framework for the future investigation of raw material provenance relative to the excavated sites, including a provisional geochemical characterization of the main sources. Keywords: EcoPLis, Raw material diversity, Central Portugal.