Complementary Use of Lead Isotopes, Tin Isotopes, and Trace Elements to Infer the Sources of Tin in Bronzes from Southern Africa, ca. 1200–1800 CE

Tin is a much rarer element (2.3 ppm in the earth’s crust) than copper (68 ppm), so in most regions, bronze can only be made with tin obtained from far away. In this paper, we investigate the sources of tin in 153 tin and bronze samples from southern Africa, dated between 1200 and 1800 CE, by integrating lead isotope, tin isotope, and trace element measurements. Our data show that tin from the prehistoric tin mines at Rooiberg (South Africa) was transported more than 900 km. We also present evidence of tin production from other sources, likely pegmatites, within the Bushveld Large Igneous Province of South Africa. Although many of the bronzes analyzed are from archaeological sites in present Zimbabwe, we have found no definite evidence so far for exploitation of tin sources within Zimbabwe.