1Department of Natural and Applied Sciences, Mount Mercy University, 2Escola Superior de Tecnologia de Tomar, Instituto Politécnico de Tomar, 3Department of Anthropology, University of Iowa, 4Department of Geoscience, University of Iowa
Friday Morning, 200ABC
This study uses strontium isotope ratios (87Sr/86Sr) from dental enamel to identify possible migrant individuals among Late Neolithic to Early Bronze Age (c. 3500-1800 BC) populations interred at the Rego da Murta I and II dolmens (Alvaiázere, Portugal). Strontium isotopes are absorbed into local plants and incorporated into the hard tissues of animals and humans through water and food intake. The isotopic composition of the bioavailable strontium depends on the local geology and the types of rocks and sediments in the subsurface. As dental enamel is formed during childhood and not subsequently remodeled, its 87Sr/86Sr ratio records the geologic signature of an individual’s childhood homeland. By comparing the 87Sr/86Sr ratio in the dental enamel of individuals in these late prehistoric collective burials with the 87Sr/86Sr ratio of local fauna and microfauna, it is possible to identify individuals who migrated to this region of Portugal after spending at least part of their childhoods in another location. For this project dental enamel was sampled from 25 humans and 8 animals from the Rego da Murta I and II dolmens. Based on the results, 20% of individuals from Rego da Murta I and 27% of individuals from Rego da Murta II can be classified as migrants. Although this data is preliminary, it suggests a good deal of geographical mobility in these populations. Additional strontium isotope mapping of the surrounding regions is necessary to identify possible places of origin.