New paragenetically constrained Re-Os molybdenite ages for El Teniente Cu-Mo porphyry deposit, central Chile

摘要

New Re-Os geochronology using molybdenite from El Teniente, Chile, confirms that several discrete mineralisation events in the Pliocene resulted in the accumulation of one of the world's largest porphyry copper-molybdenum resources. Multiple stages of vein-hosted mineralisation are associated with a temporal evolution of alteration from early biotite-orthoclase-albite-stable to late sericite-stable assemblages. The veins and alteration assemblages are associated with a series of intermediate to felsic intrusions emplaced into an andesitic volcano-sedimentary succession. We show that several short-lived pulses (10,000's -150,000 years) of magmatic-hydrothermal activity occurred over a period of 1.2 m.y. Some mineralizing episodes occurred during discrete intrusive episodes, whereas others cannot be correlated directly with recognized intrusive events.