Antigua fundición de plomo en el sitio inca de Curamba, departamento de Apurímac, Perú

• Main Authors: William E. Brooks, Luisa Vetter Parodi
• Format: Article
• Language: Spanish
• Published: Institut Français d'Études Andines 2012-07-01
• Series: Bulletin de l'Institut Français d'Études Andines
• Subjects: lead; ovens; metallurgy; Inductively Coupled Plasma
• Online Access: http://journals.openedition.org/bifea/567

Since 16th century, the Inca site of Curamba, Department of Apurímac, in southern Peru, has been interpreted as a metallurgical center for processing silver ore. However, there was no physical evidence such as fragments, or other indicators of the use of huayras or tocochimbos, which were structures traditionally used for pre-contact silver smelting in the Andes. Geochemical analyses (Inductively Coupled Plasma) of scoria excavated from the smelter pits at Curamba indicate low silver (<0,3 to 0,4 ppm), gold (<2 ppm), and copper (18 to 31 ppm) content whereas lead (155 to 234 ppm) and zinc (125 to 259 ppm) content were high. A lead-zinc signature is also indicated by the presence of arsenic, barium, iron, manganese, and vanadium. The bedrock geology at Curamba is comprised of south-dipping, fine-grained Mesozoic limestone of the regionally extensive Pucará Group. Lead-zinc occurrences are associated with the Mitu Formation, at the base of the Pucará, which crops out 1 km north of Curamba; however, no ore minerals such as galena [PbS] or sphalerite [(Zn, Fe)S] have been found at the site. On the basis of Mössbauer spectroscopy, a maximum temperature of 800 ± 50 °C was inferred for the site (Vetter et al., 2008). This temperature is more than adequate to smelt lead (~300 °C); however, higher temperatures are required to smelt silver (960 °C), gold (1,063°C), or copper (1,084 °C) and copper-silver or copper-gold alloys require temperatures of 780° to 880°C, respectively. Only a few pre-contact lead artifacts have been described (Petersen, 2010 [1970]; Vetter & Villacorta, 2001; Vetter, 2004; Velarde, 2010) and thus far there are few references to lead smelting sites in ancient Peru (Wells, 1940; Howe & Petersen, 1994).