Follow that blade! − Petroarchaeological proxies as indicators of human mobility during the Copper age of the SW of the Iberian Peninsula: Vila Nova de São Pedro case study (Portugal)

• This study increases the understanding of human mobility based on blades Petroarchaeology. • Consumption and circulation of blades from Caxarias flint suggests a preference for these artefacts in South-western Iberia. • The arrival of a large number of blades from over 500 km away highlights the site's importance in the 3rd millennium BC. Petroarchaeological proxies of blades are a powerful tool for the study of mobility in prehistoric populations to deliver more information on the network relationships of exchange, particularly during the Copper age. However, it is only recently that the first petroarchaeological studies have begun in the SW of the Iberian Peninsula, concerning Recent Prehistory. A sampling of blades from Vila Nova de São Pedro, one of the main fortified settlements in Portuguese Estremadura, was used for petrographic and geochemical study. Following the same protocol, geological samples of flint and also igneous rocks were analysed. Additionally, a techno-typological approach was combined in order to characterize the blades types in circulation. This preliminary study traced the diverse and complex dynamics of blade production, which involved the collection of the most readily available Rio Maior flint and the regionally selected Caxarias flint. There were no significant differences in knapping techniques for these two types of flint. The most distant oolitic varieties from Subbetic Cordillera (within 500 km) and the igneous rocks from the Iberian Piryte Belt (within 250 km), particularly for large blades, were not debitated at the site. Due to the high numbers of those types of materials at the site, Vila Nova de São Pedro most likely played a significant role in the complex mobility networks of large blades, establishing itself as an aggregating site and possibly a distributor of these artefacts to the Southwest of the Iberian Peninsula. Considering the proximity and the quality of Rio Maior flint sources but also to the amount of raw materials at the site sourced from a long distance, this study shows that mobility is more influenced by cultural motivations than by the availability or quality of raw materials.