Life during the Mesolithic in the Cantabrian region: new carbon, nitrogen and strontium isotopic data from dentine sequences and enamel from Los Canes Cave (Asturias, Northern Spain)

Abstract The Mesolithic period has a long history of study in the Cantabrian region (Northern Iberia) due to the relatively high concentration of human remains dating to this period. Previous analysis of stable carbon and nitrogen isotopes focussed on bone collagen, useful in broadly characterising Mesolithic diet, and particularly in identifying distinct inland and coastal diets. But this long-term average view does not permit the study of variation throughout the year that we might expect to see in hunter-gatherer diets. In this study, we present new radiocarbon dates and sequential dentine data from Los Canes Cave (Asturias), as well as some of the first enamel strontium isotope results for the area. All the new and old radiocarbon dates fell within the 6th millennium, indicating the long use of Los Canes for funerary activity. The sequential stable carbon and nitrogen isotope results show a C 3 terrestrial based diet for all the individuals. The mean δ 13 C value is -19.6‰ ± 1.0 (σ), ranging from - 21.5 to -15.2‰. The mean δ 15 N value is 9.0‰ ± 1.47 (σ) ranging from 6.5‰ to 15.8‰. The methodology used for this work also allowed us to study diet through different stages of the life cycle of these individuals, including the impact of breastfeeding and weaning, as well as to identify possible stress-related moments reflected in the isotopic data. Our data suggest a prolonged and late weaning period that took up to four years to complete. Breastfeeding probably continued as a complementary food for children to fulfil their nutritional needs and to support the immune system. Isotopic changes around the age of eleven could be associated with physiological stress related to puberty. However, there were no drastic changes in the diets, as all the individuals rely on terrestrial C 3 resources with the exception of one individual, who may have consumed low trophic marine resources for several months. The human 87 Sr/ 86 Sr values presented a mean of 0.70955 ± 0.0003, ranging from 0.70893 to 0.70981, suggesting that all the individuals spent their childhood in the region around Los Canes cave. Combining both proxies allow us to discuss the territorialization of the space, reinforcing the theory that some communities were occupying the coast, while others were focused on the inland mountains, but were in contact with each other.