Quantifying volatile budget in magma systems during shallow magma emplacement

Metallic deposits represent mineralized cupolas on the tops of the subjacent parental magma reservoirs, driven by the interaction of mineralized fluids supplied from volatile saturated oxidized magma saturated with sulfur and metal-rich, which are injected into subsurface aqueous fluid systems. Porphyry and high sulfidation epithermal deposits are related to different mineralization depths of the magmatic-hydrothermal system. Metallic deposits, as well as explosive silicic volcanism, are directly related with shallow magmatic systems. However, the giant ore deposits seem to be limited to determined places along the arcs: the Río Blanco-Los Bronces and Teniente deposits (the main Cu-deposits in central Chile) are ~100 km distant, but with many `barren' plutons of similar ages are between ore deposits. What processes differentiate mineralizing magmatic systems with respect to barren plutons?

We perform a numerical modeling of magma transport to quantify the available volatile budget transported during magma emplacement by considering first and second boiling. The volatile solubility dependence with pressure makes a hot mush reservoir 10-15 km depth the best reservoir to store volatiles and feed a giant hydrothermal system, whereas shallow intrusion that migrate laterally are unable to retain enough water for ore mineralization. However, the cooling of a long term hot mush zone underneath SFB should be delayed from the shallow intrusion, allowing residual volatile rich saturated melts rise from the crystallizing deep hot mush zone from 9 to 6 Myr. Decompression during ascent of volatile-saturated magma will increase crystallization. Magma crystallization on the upper parts of magma reservoir prevents shallower magma emplacement, favoring lateral magma migration of the reservoir if there are upper crustal structures where magma can flow through. Vertical advective systems are long-lived batholitic bodies, from where many shallow plutons can be sourced on time. This allows a mush construction at depth from where magma is able to differentiate and finally feed hydrothermal systems, allowing the development of late ore deposits at the tops of the deeper mush column. On the other hand, horizontal advective systems are sourced from these vertical batholitic systems and give place to shallow plutons horizontally emplaced.