The Geology of the Antamina Copper-Zinc Deposit, Peru, South America

Antamina is the largest known copper-zinc skarn (>3000 Mt @ 1.1% Cu and 1.3% Zinc) in the world. It is located in the Northern Andes in Peru, 270 km north of Lima. The deposit formed at approximately 10 Ma by the emplacement of quartz monzonite intrusions into Mid to Late Cretaceous limestones of the Celendin and Jumasha Formations. Mineralisation is hosted as a series of zoned green and brown garnet endoskarns and exoskarns in the form of chalcopyrite, bornite and sphalerite. Elements present within the deposit of significant quantities to affect concentrate value are Cu, Zn, Mo, Ag, Bi and Pb. Antamina produces four concentrates, namely, copper (chalcopyrite and bornite), zinc (sphalerite), molybdenum and lead-silver-bismuth.