Procurement and mobility during the Late Pleistocene: Characterising the stone-tool assemblage of the Picamoixons site (Tarragona, NE Iberian Peninsula)

Abstract

The Picamoixons site is a rockshelter located in the province of Tarragona (NE Iberian Peninsula). It was object of two rescue campaigns during 1988 and 1993, which led to the recovery of a complete archaeological assemblage, including stone tools as well as faunal and portable art remains that date the occupation to the 14th to 11th millennium BP (calibrated). This study involves a petrographic characterisation of the stone-tool assemblage in order to establish: 1) the procurement areas, 2) the raw materials management strategies and 3) the mobility radius and territorial sizes of the hunter-gatherers groups that occupied the site. The method applied comprises in a multiscale analysis that includes systematic prospection, the petrographic characterisation of geological and archaeological samples, an analysis of the chert types represented in the knapping sequence, and the definition of the mobility axes and areas frequented according to lithic procurement.A petrographic analysis of the chert in the prospected area led to the definition of nine macroscopic varieties related to five types (Vilaplana, Morera, Maset, Vilella and Tossa cherts), related to Lower and Upper Muschelkalk (Triassic), Lutetian, Bartonian (Palaeocene) and Sannonian (Oligocene) deposits.The study of the knapping sequences indicates the main exploitation of Bartonian cherts (Tossa type), and the use of Lutetian cherts (Maset and Morera types) for configuring retouched tools. The exploitation of the remaining raw material types identified is considered sporadic and opportunistic.Defining the procurement areas enabled the mobility radius to be assessed as between 3 and 30 km, highlighting the importance of the fluvial basins as natural movement pathways. The results indicate that the main procurement territory was 16 km2 in area, associable with a forager radius. The most remote procurement distances suggest a maximum exploitation area of 260 km2, defining an intra-regional range. This range presents parallelisms with various contemporaneous hunter-gatherers groups in Western Europe, suggesting a progressive mobility reduction dynamic during the Late Pleistocene-Initial Holocene.