The role of volatiles in the formation of magmatic iron oxide deposits

ended

The formation of magmatic iron oxide deposit is closely related to the role of volatiles in magmas, especially in low-Ti magmatic systems (Kiruna-type). Volatiles have strong effect on phase equilibria, saturation of Fe-Ti oxides, and liquid immiscibility. They also control the magmatic-hydrothermal transition with implications for the remobilization of some strategic elements (P, Au, Cu, REE) by fluids. Volatiles are thus key components for the relation between Kiruna-type ores and Iron Oxides Copper Gold deposits. This project is an attempt to constrain experimentally the role of volatiles in magmas related to the formation of Kiruna-type iron deposits. We will study the development of liquid and fluid immiscibility, major and trace element partitioning between melts and fluids, and iron isotopes fractionation between minerals, silicate melts and fluids. The study will benefit from unique high pressure experimental and UV-femtosecond laser ablation-ICP-MS analytical facilities developed in Hannover. The objective is to constrain the conditions and the processes responsible for the concentration of iron in low-Ti volatile-rich magmatic systems and to identify the key-factors responsible for the enrichment of elements of economic interest.