Machcán Mine: A Pb-Zn Ore Deposit in Pucará Sediments of the Atacocha District, Central Peru

The Pb-Zn deposit Machcán is situated on the western slope of the Cordillera Oriental, 24 km north of Cerro de Pasco town (Fig. 1). The Machcán Mine belongs to the Atacocha mining district; the bigger and better-known skarn ore deposits Atacocha and Milpo occur to the immediate south of Machcán. Mining in Machcán takes place at altitudes between 4080 and 4180 m. The mine was operated by the Compania Minprosa S.A., Lima. During the mid-1970’s, between 120 and 160 tons of lead and zinc concentrate were produced per month; at that time the average ore grade amounted roughly to 5% Pb and 5%–7%Zn.