Strontium isotopes and the geographic origins of camelids in the Virú Valley, Peru

This study presents the strontium isotopic composition of camelid tooth enamel from Huaca Santa Clara, Huaca Gallinazo, and Huancaco in the Virú Valley, northern Peru. These sites were occupied during the Early Intermediate Period (EIP, c. 200 BCE-600 CE) with Huaca Santa Clara and Huancaco being associated with ritual sacrifices of camelids during the late Middle Horizon (LMH, 850–950 CE for Huancaco and c. 1150 CE for Huaca Santa Clara). Most camelids had strontium isotopic compositions that fell within the predicted isotopic range for the Virú Valley. Isotopic compositions of the serially sampled teeth suggest most camelids did not move between regions with different strontium isotope baselines during enamel formation. At Huaca Gallinazo, the capital of the Virú Polity during the EIP, all the camelids appeared to be local to the lower Virú Valley. At Huaca Santa Clara, a regional administrative center, butchered individuals associated with the EIP occupation had strontium isotope ratios reflecting primarily local origins, with some evidence of individuals from the highlands. The scarified individuals at Huaca Santa Clara (late Middle Horizon) all had strontium isotope ratios consistent with a local origin in the Viru Valley. At Huancaco, some butchered (EIP) and sacrificed (LMH) camelids were local to the Virú Valley but this site may have included more individuals with higher tooth enamel 87Sr/86Sr, possibly originating in the middle and upper valley regions relative to the other two sites. These data confirm that camelid husbandry was present on the north coast at least as early as the EIP and this practice was maintained through the late Middle Horizon after the waning of north coast polities such as Virú and Moche.