INTENSIVE PRE-INCAN METALLURGY CHRONICLED BY LAKE SEDIMENTS IN THE SOUTHERN BOLIVIAN ANDES

The history of pre-Columbian metallurgy in South America is incomplete because the extent of looting has left most precious metal artifacts without reliable geographical and cultural contexts. Here, we reconstruct a millennium of metallurgical activity at Cerro Rico (Potosí, Bolivia), the world’s largest silver deposit, using the stratigraphy of metals directly associated with smelting (Pb, Sb, Bi, Ag, Sn) from dated lake sediments. Two distinct intervals of elevated metal concentrations are recorded, the first coinciding with the terminal stages of Tiwanaku culture (1000-1200 A.D.) and the second occurring during Inca and early Colonial times (1400-1650 A.D.). The first of these events indicates that Cerro Rico ores were actively smelted at a large scale in the Late Intermediate Period, providing new and compelling evidence for a major pre-Incan silver industry.