Tiwanaku residential mobility in the South Central Andes: Identifying archaeological human migration through strontium isotope analysis (Peru, Bolivia, Chile)

During the Middle Horizon (ca. AD 500--1100), Tiwanaku-style material culture is found throughout the South Central Andes. However, although the Lake Titicaca Basin site of Tiwanaku has been studied extensively, the nature of Tiwanaku influence is still debated. In the present study, the nature of the sociopolitical organization of the Tiwanaku polity and its relationship to peripheral zones in the South Central Andes is elucidated through strontium isotope analysis. Unlike previous studies, strontium isotope analysis can identify individuals who lived in the Lake Titicaca Basin during childhood yet moved to and were buried in Tiwanaku-affiliated sites outside of the Lake Titicaca Basin. Identification of Tiwanaku immigrants or colonists outside of the Lake Titicaca Basin has shown that Tiwanaku strategies of incorporation and integration were highly variable. In some cases, such as in the Upper Osmore Drainage, Tiwanaku-affiliated sites appear to be true colonies inhabited by individuals who had previously lived in the southeastern Lake Titicaca Basin. In other cases, such as in the San Pedro de Atacama region, individuals buried with Tiwanaku grave goods are not in fact Tiwanaku colonists, and appear to have adopted Tiwanaku-style goods to demonstrate religious, political and/or economic ties to the Tiwanaku polity. Therefore, this research demonstrates the varied and complex means of sociopolitical integration utilized by the Tiwanaku polity, and refutes simplistic and monolithic views of Tiwanaku expansion during the Middle Horizon.