Petrochemistry of highly reduced systems

The meteorite record is characterised by a wide variety of both chondritic and achondritic meteorites. While the minerals found in these rocks are frequently predicted to have condensed from a gas of solar composition; particular groups of meteorites, namely the enstatite chondrites and the closely related aubrites, contain minerals such as TiN and CaS, which must have formed under much more oxygen-poor conditions. Owing to their rarity, these systems remain largely unstudied, despite the fact that the Earth shares many isotopic features with the enstatite chondrites. Moreover, their relevance for the formation of Mercury (Jäggi et al. 2021), which has a larger core/mantle ratio than any other terrestrial planet, warrants further study of reduced systems. Our group, together with the High Pressure Geology group, is engaged in the experimental investigation of such reduced assemblages, and how their distinct chemical and physical properties influence the formation and differentiation of planets, in particular Mercury.