The Distribution and Timing of Molybdenite Mineralization at the El Teniente Cu-Mo Porphyry Deposit, Chile

Pulsed magmatic fluid release for the formation of porphyry deposits: Tracing fluid evolution in absolute time from the Tibetan Qulong Cu-Mo deposit

“…Based on the pulsed hydrothermal process suggested here, together with cyclic mineralization processes constrained by recent high-precision U-Pb and Re-Os dating, titanium diffusion modeling, and concentric excess aluminum in plagioclase (Mercer et al, 2015;Spencer et al, 2015;Tapster et al, 2016;Williamson et al, 2016;Li et al, 2017a), we propose that a pulsed magmatic-hydrothermal process is common in the formation of porphyry deposits. Such a process is most likely controlled by periodic fluid release during gradual cooling of the source pluton at depth (Chelle-Michou et al, 2017), although a decline in the amount of melt and fluid associated with multiple recharging events is a competitive alternative mechanism.…”

“…Such an assumption is used in numerical simulations to provide insights into the hydrothermal controls of ore formation. In contrast, a pulsed hydrothermal process is obvious for active magmatic systems, and also has been proposed for the formation of porphyry deposits, as shown by high-precision U-Pb zircon and Re-Os molybdenite dating (Stein, 2014;Spencer et al, 2015;Buret et al, 2016;Tapster et al, 2016;Li et al, 2017a). However, the duration of a geological event could be significantly underestimated from a relatively small number (e.g., <10) of chronologic determinations (Glazner and Sadler, 2016); hence, the intermittent pulses inferred from radiometric dating could be biased from dating a protracted event.…”

“…Traditionally, this is done via the relative time frame defined by vein types, and in a single mineralization event/pulse, an A-type vein is earlier than a B-type vein, with a D-type vein being the latest (Sillitoe, 2010). However, the relative chronology of veining cannot be correlated at a deposit scale confidently, especially with the presence of multiple mineralization pulses (Stein, 2014;Mercer et al, 2015;Spencer et al, 2015;Li et al, 2017a).…”

The controls of post-entrapment diffusion on the solubility of chalcopyrite daughter crystals in natural quartz-hosted fluid inclusions

“…8b) with sericitic halos. These veins were formed by the same fluids as they migrated outward and upward and cooled (Spencer et al, 2015). In the type 6b veins the vapor inclusions contain Cu concentrations of up to 8000 ppm (Fig.…”

Petrography, geochemistry and geochronology of granite hosted rhyodacites associated with a disseminated pyrite mineralization (Arnolz, Southern Bohemian Massif, Austria)

“…There are also no observations pointing to multiphase magmatic events and related hydrothermal activities respectively as described from classic porphyry deposits (e.g. Spencer et al 2015) and, finally, there are no signs of hydrothermal breccias frequently occurring in apical parts of porphyries (Sillitoe 2010 the felsitic dykes around Litschau-Homolka-Lasenice (BLitschau dyke swarm^; Klomínský et al 2010b), predominantly striking NW to N are geochemically specialized in the sense that they derived from highly differentiated granitic magmas (c.f., Homolka granite!) in contrast to the studied dykes in and around the quarry Arnolz.…”