Strontium isotopes of human remains from the San Martín de Dulantzi graveyard (Alegría-Dulantzi, Álava) and population mobility in the Early Middle Ages

Strontium isotope analysis of human remains from San Martín de Dulantzi (Alegría-Dulantzi, Álava, Spain) graveyard has been used to establish mobility patterns during the Early Middle Ages. Some archaeological human remains had Germanic grave goods. Through radiogenic strontium isotope analysis, local origin individuals and immigrants were differentiated. Archaeological human bone samples exhibit 87Sr/86Sr = 0.70779–0.70802 values similar to domestic fauna isotope composition, indicating local origin of individuals or long residence time in the region. Comparing these data with tooth enamel values, two groups of immigrants from distinctive geological environment were established. The Dulantzi population constituted mainly a local society with influxes of immigrants. The foreign individuals are distributed through the studied period of time, suggesting that migration movements were limited in number. Isotopic signatures indicating mainly local individuals, linked to grave goods with archaeological attribution to Germanic origin, question the previous ethnic paradigm.