Strontium narratives: scales of human paleomobility and exceptional journeys through the southern Andes and deserts of Argentina and Chile

R. BARBERENA; AUGUSTO TESSONE; C. LLANO; DURÁN, VÍCTOR; P. NOVELLINO; E. MARSH; A. GASCO; C. FRIGOLÉ; F.SANTANA; PETRUS LE ROUX

Karratha

Conferencia; Southern Deserts 5: Desertscapes; 2019

In this presentation we reconstruct the spatial scales and ecological complementarity between deserts and highlands in the southern Andes of Argentina and Chile (32¼-34¼S) during the last 2300 years by means of strontium isotopes (87Sr/86Sr). Radiogenic strontium isotope values vary according to bedrock age and composition and can be used to infer the geographic sources of dietary strontium, hence revealing human movements between geologically distinct areas. The isotopic analysis of human tissues formed during different age periods allows characterizing the life histories of individuals. We present ageological framework for the analysis of bioavailable strontium based on the combination of the geological data with isotope results for plant and faunal samples. The 87Sr/86Sr values from human samples indicate residential stability within geological regions along life history. When comparing strontium and oxygen values for the same human samples, we record a divergent pattern: while_18O values for samples from distant regions overlap widely, there are important differences in 87Sr/86Sr values. Despite the large socio-economic changes recorded, 87Sr/86Sr values indicate a persisting scenario of lowsystematic mobility between the different geological regions. Our results suggest that strontium isotope values provide the most germane means to track patterns of human occupation of distinct regions in complex geological landscapes.