Using oxygen 18 isotope to problematize the presence of resettled laborers in the far provinces of the Inca empire

Resettlement, as a major imperial policy in the Inca empire, appears to have been a widespread mechanism for labor mobilization and the dismantling of rebellions. While multiple ethnohistorical references exist regarding resettlement in the central Andes, the extent of this policy in the imperial provinces is still unknown, especially in cases of economic intensification that might have required more labor force. The δ(18)O isotope is a good proxy for human mobility when comparing the childhood isotopic signature in the teeth enamel and the local water signature at the place of death. If applied to the study of an archaeological sequence, we can observe the expansion or reduction of a population’s displacement within a territory, if they received foreigners, and in general, how their social interaction and networks changed over time. In a marginal provincial setting of the Inca empire, such as Copiapó valley in Chile, the study of δ(18)O isotope can enable us to observe if the alleged economic intensification in metallurgical production implied the massive arrival of foreign populations. Significantly, the Late Horizon does not evidence a great change in terms of mobility, compared to previous periods in Copiapó valley. Thus, the isotopic evidence can more clearly illuminate the social and political dynamics of an imperial provincial setting, where economic activities demanded by the Inca state were mainly carried out by the local labor force.