Geology, metallogenic features and genesis of the El Teniente porphyry copper-molybdnum deposit in Central Chile

The El Teniente deposit, one of the world's largest known copper-molybdenum deposits, contains 12.4 billion metric tons copper ore at 0.62 percent Cu and 7.8 billion metric tons molybdenum ore at 0.018 percent Mo. It is located in the Late Miocene to Early Pliocene copper-molybdenum metallogenic province of Central Chile Andean Cordillera. The deposit occurs in a Late Miocene volcanic active belt. The mid-Late Miocene Farellones Formation hosts the El Teniente copper-molybdenum deposit. The Farellones Formation is underlain by the Coya-Machali Formation. The contact between the two formations is structural or locally unconformable. The El Teniente deposit occurs in a late Miocene volcano-plutonic complex, which is part of the Farellones Formation, consisting of a thick sequence of eruptive and intrusive rocks of basaltic to rhyolitic compositions. The main host rocks of the deposit are andesites, felsic-intermediate intrusive rocks and the Braden pipe breccia that intruded into andesites. The characteristics of the fluid inclusion assemblages suggest that the hydrothermal activity and mineralization at El Teniente can be divided into four stages. The fluid inclusion component research shows that the ore-forming process of the El Teniente deposit resulted from injection of a deep-sourced Cu-rich and probably S-rich fluid into a more continuously devolatilizing subvolcanic large magma chamber.