Migration scale, process, and impact in the Tiwanaku colonies: Paleomobility at the archaeological site of Omo M10

Contemporary migrations show form and intensity of interaction between homeland and host communities to shape social dynamics and identities. We apply here a contemporary theoretical framework and biogeochemical analyses to elucidate the scale, processes, and impacts of migration in the Tiwanaku polity (6th-11th c. CE) by inferring the mobility of individuals interred at the Tiwanaku-affiliated site of Omo M10 (Moquegua Valley, Peru).

For each of 124 individuals, we captured paleomobility across the life-course by analyzing up to four enamel and bone samples that formed during discrete developmental periods for radiogenic strontium (⁸⁷Sr/⁸⁶Sr) and stable oxygen (δ¹⁸O_{carbonate(VPDB)}) isotopes.

At Omo M10, archaeological human enamel and bone values range from ⁸⁷Sr/⁸⁶Sr = 0.70632-0.72183 and δ¹⁸O_{carbonate(VPDB)} = -13.4‰ to +1.7‰, with a mean of ⁸⁷Sr/⁸⁶Sr = 0.70763 ± 0.00164 (1σ, n = 334) and δ¹⁸O = -7.8‰ ± 1.9‰ (1σ, n = 334).

Together with archaeological evidence, we interpret these data as evidence for multigenerational interaction between communities in the high-altitude Tiwanaku heartland and at the site of Omo M10. Our results suggest that one-fourth of individuals spent some part of their life outside of Moquegua and one in eight individuals from Omo M10 were first-generation migrants. Greater mobility of females and juveniles at Omo M10 indicates that gender and family were important social constructs in maintaining relationships and cultural continuity in provincial Tiwanaku life, and communities maintained autochthonous migration streams with Tiwanaku-affiliated populations throughout the south-central Andes. Intra-individual biogeochemical analyses of migration at Omo M10 contribute a nuanced perspective on the diverse experiences of multigenerational Tiwanaku colonies.