The Lithologic, Stratigraphic, and Structural Setting of the Giant Antamina Copper-Zinc Skarn Deposit, Ancash, Peru

      Antamina, located at latitude 9? 32' S and longitude 77? 03' W in the Ancash Department of north-central Peru, is the largest known Cu-Zn skarn ore deposit. It incorporates a mineral reserve of 561 Mt, which has an average grade of 1.24 percent Cu, 1.03 percent Zn, 13.71 g/t Ag and 0.029 percent Mo, calculated at a 0.7 percent Cu equiv cutoff grade. The grandite-dominated calcic skarn formed in and around an upper Miocene porphyritic monzogranite stock emplaced into Upper Cretaceous carbonate strata that had experienced thin-skinned, northeast-verging thrusting and folding in the late Eocene Incaic orogeny. The exoskarn Cu-Zn ore is discordant to the strata of the Jumasha and overlying Celend

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