A handheld XRF study of Late Horizon metal artifacts: implications for technological choices and political intervention in Copiapó, northern Chile

Abstract

A sample of 403 Late Horizon (~1400–1530 AD) metal artifacts from Copiapo in the Atacama Desert of northern Chile, consisting of at least 14 artifactual categories, were examined by a Niton pXRF analyzer for compositional information. The results revealed patterned use of different alloys in the Copiapo region, including a very strong, region-wide reliance on bronze alloys, with tin being a primary or secondary alloying element. The wide use of a non-local metal (tin) in the Copiapo region is interpreted as the result of the Inca Empire’s political control over indigenous economic productive activities, despite the long distance to the empire’s core area. However, arsenical bronzes featured local artifact typologies in a relatively large quantity during the same period, suggesting that the Incas’ preference for bronzes alloyed with tin should have influenced but not fully changed the indigenous metallurgic traditions. This shows that the Inca state had powerful but not absolute control over metal resources in the Atacama Desert.