INDUSTRIAL LEAD IN ANCIENT PERU: THE CURAMBA SMELTER AND LEAD SLING BULLETS

Since the 16^th century, the Inca site of Curamba, Dept. Apurímac, in southern Perú, has been interpreted as a metallurgical center for processing argentiferous galena. Yet there was no physical evidence of the use of huayras or tocochimbos, the meter-sized stone or clay structures traditionally used for silver smelting in the ancient Andes, only numerous burned, rock-lined depressions (hornos).

Inductively Coupled Plasma analyses of the scoria from the hornos indicate low Ag (0.3–0.4 ppm), Au (<2 ppm), and Cu (18–31 ppm); whereas, Pb (155 –234 ppm) and Zn (125–259 ppm) were high. A lead-zinc signature is also indicated by elevated As, Ba, Fe, Mn, and V. The bedrock geology at Curamba is comprised of south-dipping, fine-grained Mesozoic limestone and lead-zinc occurrences are associated with the Mitu Formation, which crops out only 1 km north of Curamba.

Ancient stone sling ammunition found at several archaeological sites in Perú indicates that the sling (Spanish honda; Quechua huaraca, warak'a) was used in ancient Perú and it was the Inka weapon most feared by the Europeans. Several lead artifacts from ancient Perú have been described simply as bars (lingotes) or weights (pesos); however, these might be more accurately described as: 1) biconic to ovoid (30-60 mm, 30-40 g), and 2) spherical (35 mm, 80-160 g). Therefore, in composition, dimensions, form, and weight, these pre-contact Peruvian lead artifacts are strikingly similar to lead sling ammunition from Old World battle sites in Spain and the Mediterranean, and are herein interpreted to have served a similar function in ancient Andean warfare.