Gondwanan magmatism with adakite-like signature linked to Cu (Mo)-porphyry deposits from the San Rafael Massif, Mendoza Province, Argentina

The magmatic–hydrothermal evolution of the San Pedro porphyry Cu‐(Mo) deposit: Implications for the metallogenesis of the Permian magmatism in the western margin of Gondwana

“…Different styles of mineralization are recorded in the upper and lower sections and have been linked to the geodynamic evolution of the Choiyoi Magmatic Cycle (Carpio et al ., 2001). Porphyry‐type Cu‐(Mo) deposits (San Pedro, La Chilca‐ Zanjón del Buitre and Infiernillo) are hosted by the lower section (Di Tommaso and Rubinstein, 2007; Gómez and Rubinstein, 2010; Rubinstein et al ., 2012; Gómez et al ., 2015), whereas porphyry Mo prospects (Carpio et al ., 2001) and epithermal low sulfidation‐type deposits (Rubinstein and Gargiulo, 2005; Gargiulo et al ., 2007) are related to the upper section. The petrogenetic analysis of the lower‐section volcanic rocks suggests that the magmatism with an adakite‐like signature was generated under thickened crust tectonic conditions (Gómez et al ., 2015).…”

“…Porphyry‐type Cu‐(Mo) deposits (San Pedro, La Chilca‐ Zanjón del Buitre and Infiernillo) are hosted by the lower section (Di Tommaso and Rubinstein, 2007; Gómez and Rubinstein, 2010; Rubinstein et al ., 2012; Gómez et al ., 2015), whereas porphyry Mo prospects (Carpio et al ., 2001) and epithermal low sulfidation‐type deposits (Rubinstein and Gargiulo, 2005; Gargiulo et al ., 2007) are related to the upper section. The petrogenetic analysis of the lower‐section volcanic rocks suggests that the magmatism with an adakite‐like signature was generated under thickened crust tectonic conditions (Gómez et al ., 2015). Furthermore, the U/Pb LA‐ICP‐MS ages of magmatic zircons from an intrusive unit associated with the San Pedro porphyry deposit (263.1 ± 4.2 Ma) confirm that the emplacement of the mineralization occurred throughout the change in the geodynamical conditions during the waning of the magmatic arc in a flat slab setting (Japas et al ., 2013; Gómez et al ., 2015).…”

“…The petrogenetic analysis of the lower‐section volcanic rocks suggests that the magmatism with an adakite‐like signature was generated under thickened crust tectonic conditions (Gómez et al ., 2015). Furthermore, the U/Pb LA‐ICP‐MS ages of magmatic zircons from an intrusive unit associated with the San Pedro porphyry deposit (263.1 ± 4.2 Ma) confirm that the emplacement of the mineralization occurred throughout the change in the geodynamical conditions during the waning of the magmatic arc in a flat slab setting (Japas et al ., 2013; Gómez et al ., 2015).…”

“…The San Pedro deposit is part of a cluster of porphyry‐type deposits (El Infiernillo, La Chilca‐Zanjón del Buitre, see Figure 1a) related to the Gondwanan magmatism in the San Rafael Massif (~281–252 Ma, e.g., Rocha‐Campos et al ., 2011), which is situated over 300 km to the southeast from the world‐class Miocene–Pliocene porphyry Cu‐Mo deposits of El Teniente, Los Pelambres, and Rio Blanco‐Los Bronces in Chile (Figure 1b). A previous study (Gómez et al ., 2015) showed that the Gondwanan mineralizing magmatism has an “adakitic signature” similar to the large and younger deposits closely linked to the Central Andean geodynamic subduction setting (Cline and Bodnar, 1991; Thiéblemont et al ., 1997; Oyarzún et al ., 2001; Rabbia et al ., 2002; Reich et al ., 2003; Richards and Kerrich, 2007; Chiaradia et al ., 2012; among others), indicating that the San Pedro deposit might have a favorable magmatic source to form an economic deposit.…”

Reverse Osmosis contributing to metal zoning in porphyry type deposits: A case study

“…6)and consequent supersaturation and base metal precipitation. This assumption would also be supported by comparisons with other Permian porphyry copper deposit (San Pedro) located some 100 km south of the Infiernillo deposit, where a phyllic halo is absent and Cu anomalies are mainly restricted to polymetallic veins with phyllic envelopes(Gómez et al, 2014).…”