LAUSR

Abstract There are few carbon and nitrogen isotope ratio studies for prehistoric periods in the northern part of the Iberian Peninsula, none of strontium isotopes. While most of the questions so-far addressed have been concerned with the transition to farming, the transition to social complexity has been greatly ignored even if multi-isotope studies could shed new light on internal socioeconomical dynamics during the emergence of complex societies in the region. The present study analyses a total of 67 archaeological samples (28 from human bones, 13 from animal bones and 26 from human tooth enamel) obtained from the deposits at Santimamine (Kortezubi, Bizkaia) and Pico Ramos (Muskiz, Bizkaia) dated to the Mesolithic, Late-Neolithic and Chalcolithic periods, and samples from different geological areas to characterize the bioavailable strontium of the region. These analyses provide new data about the diet on the coast of the Basque Country, confirming that the consumption of seafood was irrelevant already during the later stages of the Neolithic. The first 87 Sr/ 86 Sr analyses suggest the possibility of migration movements from other parts of Northern Iberia (i.e. Navarra) to the sites being studied.