STABLE ISOTOPE STUDIES IN THE SALITROSO LAKE BASIN (SOUTHERN PATAGONIA, REPUBLICA ARGENTINA): ASSESSING DIET AND MOBILITY OF LATE HOLOCENE HUNTER-GATHERERS

TESSONE, A.; ZANGRANDO, F.; BARRIENTOS, G.; GOÑI, R.; PANARELLO, H.O.; CAGNONI, M. C.

INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY

John Wiley & Sons, Inc

Lugar: Londres; Año: 2009 vol. 19 p. 297 - 308

1047-482X

Within the framework of an ongoing research oriented to investigate the socioecology of Late Holocene hunter-gatherers from the Salitroso lake (Southern Patagonia, República Argentina), this work aims to present the carbon and nitrogen stable isotope data currently available for human and environmental samples in order to discuss the diet and mobilitypatterns of such populations. It is considered that the prehistoric population of this region and the nature of the settlement during the Late Holocene were strongly conditioned by climatic fluctuations, particularly those related to the Mediaeval Climatic Anomaly (MCA). As a consequence of the persistent droughts associated with MCA, a set of organisational changes occurred, being the reduction in residential mobility and the resulting spatial constriction ofpopulations the main effects on the short and medium term. The combined use of different stable isotopes (e.g. C, N) is a suitable research strategy for testing hypothesis related to prehistoric mobility. Under this general assumption, archaeological human and faunal skeletal remains are sampled as well as modern vegetal and faunal tissues in order to better understand the isotopic ecology at a regional level. As a chronological frame there are available data pertaining to a sample of 24 human skeletons, 19 of which have been radiocarbon dated between (2750 and300) cal. BP. The stable isotope values corresponding to this sample are: d13C (n = 24) = -19.05 ± 0.65 , and d15N (n=11)= 11.77 ± 0,92 . These results highlight the importance of terrestrial C3 ecosystems as the main source of dietary resources for the hunter-gatherer populations of the Salitroso lake basin, suggesting a very low intake of marine resources. This agrees with the idea of a predominant low residential mobility of that population, mostly limited to inland habitats. Almost all contemporary human skeletons recovered near the Atlantic seashore inSouthern Patagonia show isotopic compositions indicating marine or mixed marine-terrestrial diets. Conversely, in the Salitroso lake basin a pattern of increasing regionalisation during late prehistoric times is now coming into light and needs to be thoroughly investigated from a supraregional perspective.