Metal fluxes in the oceanic crust and implications on the formation of hydrothermal mineralizations

Future discovery of mineral resources requires a better understanding of the mineralized system at large scale. Metal fluxes in the oceanic crust have direct and indirect impact on the formation and composition of hydrothermal mineralizations in active black smoker systems, but also in their ancient analogues including volcanogenic massive sulfides and possibly in some epithermal-porphyry systems. These fluxes occur at different stages during the evolution of the oceanic crust and in very diverse tectonic environments, such as slow- and fast-spreading ridges, back-arc basins, island-arcs and continental-arcs, strongly affecting the intensity and nature of the fluxes. Seafloor hydrothermal alteration is critical for hydrothermal ore deposit formation, but it is still poorly constrained in many tectonic environments. Of particular importance are magmatic-hydrothermal processes related to crustal formation, especially in arc-related environments. The competitive effect of sulfide saturation and magmatic degassing during magmatic differentiation can strongly affect the metal endowment of a system, but over whole remains poorly understood. Finally, oceanic crust dehydration in subduction zones has strong impact on the overlying mantle composition and its redox condition, but metal fluxes remain elusive and can possibly have far reaching implications on the formation of hydrothermal mineralizations in oceanic and continental arc environments. In this session we welcome field based, experimental or modelling studies which focus on metal fluxes from modern day oceanic crust or ophiolites.