Stable isotope analysis of human and animal remains from the Late Upper Palaeolithic site of Balma Guilanyà, southeastern Pre-Pyrenees, Spain

Abstract

Stable isotope analysis of carbon ( 13C/ 12C) and nitrogen ( 15N/ 14N) was performed on collagen extracted from three human and five herbivore bone and tooth samples from the Late Upper Palaeolithic site of Balma Guilanyà (Catalonian Pre-Pyrenees, Spain). Contextual and palaeoecological data as well as radiocarbon dates indicate that the studied occupation phase took placed during the Bolling/Allerod interstadial (GI-1a event). The human remains were co-mingled without any anatomical association, corresponding to a minimum number of three individuals, and it was not possible to determine if the three analyzed samples are from one or more individuals. The mean isotope values obtained from the human remains are δ 13C = −19.8‰ and δ 15N = 6.7‰, while those of the large herbivores (red deer and wild goat) were −19.8‰ and 1.7‰ for δ 13C and δ 15N respectively. This indicates that the main source of protein in the diet of the Balma Guilanyà human(s) came from terrestrial herbivores. There is no zooarchaeological or isotopic evidence for the consumption of freshwater or marine resources at the site, which lies 80 km from the present Mediterranean coast. The low δ 15N values observed in both human and animal samples correspond to a trend reported by other researchers working in northwestern Europe: a significant δ 15N reduction in collagen from bones datable within 20,000–10,000 BP, followed by a rise to present values in the Early Holocene. This phenomenon, generally attributed to climatic and/or pedological processes, had not been previously observed in the Mediterranean region and, until now, was thought to be restricted to northern Europe.