Program > Browse abstracts by speaker > Namur Olivier

Carbon solubility in reduced silicate melts plays a pivotal role in the evolution of planets, particularly those with highly reducing conditions, like Mercury. Under such conditions, carbon is thought to preferentially partition into metallic species, leading to low solubility in silicate melts and, theoretically, a low-carbon magma ocean. Experimental studies on silicate melts representative of Mercury's mantle, however, reveal significant carbon solubility in the form of CH4. This elevated solubility likely influenced Mercury's differentiation, resulting in the formation of a graphite crust as carbon exsolved during cooling and crystallization. Detected by MESSENGER, this graphite crust serves as a volatile reservoir and may explain surface features like hollows and Mercury's low-reflectance material. These findings highlight the role of carbon speciation and mobility in planetary evolution and suggest similar processes may occur on other reducing planetary bodies or exoplanets.