Lung-powered copper smelting on the Pampa de Chaparri, Lambayeque department, Peru

Summary

We report here the archaeometallurgical analysis of residues associated with two banks of four lung-powered copper smelting furnaces at site 256AO1, discovered during Hayashida's full-coverage survey of the Pampa de Chaparri in 2008. Calibrated radiocarbon dates place the operation of the furnaces in the Middle Sican period, ca. 1000-1200 cal AD. The furnaces are similar in size and shape to those excavated by Shimada and Epstein at Cerro Huaringa, which is only 15 km away; the smelting process that we reconstruct differs in some significant respects. At Cerro Huaringa, copper prills were trapped in a pasty slag, which was crushed on giant grindstones (batanes) to recover the metal. At 256AO1, fluid slags separated cleanly from copper, and there are no batanes. The ore smelted was weathered chalcopyrite (CuFeS2) and furnace atmospheres were evidently very reducing, as at least some of the copper was contaminated with metallic iron. This was removed by refining the metal on shallow ceramic plates, about 20 cm in diameter, under a more oxidizing atmosphere. The copper metal contains 1-5% arsenic, but we are unable to determine whether arsenic minerals were part of the copper ore, or whether they were deliberately added.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)   •
• Archaeometallurgy of the New World: Current Research, Approaches, and Methods

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Record Identifiers

Abstract Id(s): 15139