Formation of monomineralic Fe-Ti oxide ores in the high-Ti ferrobasaltic system: A case study in Emeishan, China

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Magmatic iron ore from layered intrusions is one of the major sources for Fe, Ti and V metals used in industrial processes. The origin of the Fe-Ti-V oxide-rich layers is still poorly understood and may involve different processes, depending on the natural case studies. In this study we will combine the geochemical study of natural samples (under the responsibility of Chinese partners of Beijing) and an experimental approach (under the responsibility of the German partners) to understand the formation of the nearly monomineralic magnetite layers in the Emeishan Large igneous Province (ELIP), China. Such monomineralic deposits are uncommon and, in the case of the Emeishan Province, geochemical and natural observations indicate that melt immiscibility does not play a major role during the formation of the ores. The research program aims at understanding the formation of magnetite-layers from ELIP and will tackle the following questions:- Which factors do exert a major control on the stability of Fe-Ti oxides during the evolution of the most primitive high-Ti ferrobasalt and what is the most Fe-Ti-rich melt composition during magma differentiation? - To which extent can interaction between basaltic magmas and limestone (occurring as host-rock) affect magma differentiation and the crystallization behavior of Fe- and Ti-bearing minerals?- To which extent can magma replenishment, i.e. mixing between evolved and primitive magmas, increase the stability field of Fe-Ti-oxides or affect the conditions at which Fe-Ti-oxides are the only stable solid phases?The complementarity of the geochemical characterization of rocks and minerals (major and trace elements) and of the constraints gained from high pressure experiments will provide quantitative constraints on the magma evolution history in the layered intrusions of Emeishan province.