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@article{Spencer:2015:10.2113/econgeo.110.2.387,
author = {Spencer, ET and Wilkinson, JJ and Creaser, RA and Seguel, J},
doi = {10.2113/econgeo.110.2.387},
journal = {Economic Geology},
pages = {387--421},
title = {The Distribution and Timing of Molybdenite Mineralization at the El Teniente Cu-Mo Porphyry Deposit, Chile},
url = {http://dx.doi.org/10.2113/econgeo.110.2.387},
volume = {110},
year = {2015}
}
TY - JOUR
AB - The El Teniente Cu-Mo porphyry deposit, Chile, is one of the world’s largest and most complex porphyry ore systems, containing an estimated premining resource of approximately 95 Mt Cu and 2.5 Mt Mo. Although Cu mineralization at the deposit is quite well studied, little work has focused specifically on the distribution and timing of Mo mineralization. Combined grade, vein, and breccia distribution analysis reveals that deposit-wide Mo grades of 0.01 to 0.06 wt % are strongly controlled by the abundance of main mineralization (type 6a) quartz ± molybdenite veins. These show a clear spatial relationship with several felsic-intermediate intrusions and appear to develop outward and upward into Cu-rich (type 6b–7b) quartz-chalcopyrite veins and (type 8) chalcopyrite-anhydrite ± bornite veins with sericitic alteration halos. High-precision Re-Os molybdenite dating reveals that these linked vein types did not develop in a single, deposit-wide evolution, but are diachronous, related to distinct episodes of hydrothermal activity associated with the emplacement of diorite finger porphyries and the composite Teniente Dacite Porphyry. These units acted as effective, short-lived (<100,000 years) conduits for pulses of Mo- and Cu-bearing hydrothermal fluids between 6.3 and 4.6 Ma. The rapid thermal contraction of each system during mineralization led to extensive overprinting of Mo-rich veins by their lower-temperature, Cu-rich equivalents. Separate pulses in magmatic-hydrothermal activity are separated by distinct gaps of up to 300,000 years, during which Mo-mineralizing activity appears to have gone into quiescence.Mo grades exceeding 0.06 wt % correspond to the presence of molybdenite-bearing, late mineralization-stage, tourmaline-cemented (type 9), and anhydrite-carbonate ± gypsum (type 10) veins and breccias. These are abundant at shallow mine levels and show a close spatial relationship with a series of concentric faults associated with
AU - Spencer,ET
AU - Wilkinson,JJ
AU - Creaser,RA
AU - Seguel,J
DO - 10.2113/econgeo.110.2.387
EP - 421
PY - 2015///
SN - 0361-0128
SP - 387
TI - The Distribution and Timing of Molybdenite Mineralization at the El Teniente Cu-Mo Porphyry Deposit, Chile
T2 - Economic Geology
UR - http://dx.doi.org/10.2113/econgeo.110.2.387
VL - 110
ER -
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