Chert procurement for inferring Neanderthal mobility in central western Iberia

Chert was one of the preferred lithic raw materials used across Prehistory whatever the continent. To acquire it, people moved across large distances and developed networks with other territories and with the other groups therein. Some of the reasons for such effort are the ability of chert to produce extremely sharp cutting edges, the great predictability of its knapping, retouch and shaping processes, and the endurance of the edges.Because stone-tools are the most available and reliable sources of information on prehistoric human behavior, and because chert sources have specific macroscopic and geochemical features, this raw material is one of the most used to infer the mobility and economical patterns of prehistoric populations.Neanderthals inhabited western Iberia from ca. 200 ka to 40 ka, and most of the Mousterian sites have chert in their assemblages. In this study we analyze the chert assemblages from the Mousterian layers of Gruta Nova da Columbeira, Praia Rei Cortiço and Mira Nascente through macroscopic, PIXE and pXRF analysis. Results suggest as possible provenance regions the nearby coastal bluffs and stream deposits draining across the Jurassic bedrock toward the Óbidos valley. Little is still known about the chert sources from Portugal and how they fit into the archaeological sites. With Gruta Nova da Columbeira, Praia Rei Cortiço and Mira Nascente being reference sites to the Portuguese Mousterian, this study allows us to deepen the study of human population dynamics and the relationship with regional resources and landscape in the Late Pleistocene.