A speciation model linking the fate of carbon and hydrogen during core – magma ocean equilibration

The core – mantle differentiation in the magma ocean constitutes a major planetary event that involved two elements are essential to life: carbon (C) and hydrogen (H). These conventionally classified as volatiles (i.e. atmophile), but they can also evolve into being siderophile lithophile at extreme conditions found oceans. We report here model for H C species dissolved silicate melts equilibrium with iron-rich alloys under variable pressure, temperature redox conditions. This speciation is able reconcile reproduce large body of experimental data on metal–silicate partitioning carbon-saturation C-undersaturated systems. At low we conclude prevailing CO2, CO, H2O, H2, whereas CH4 appears dominate high pressure. changes explain recent observations (i) evolves from strongly pressure moderately (ii) not becomes increasingly so rises. Moreover, it shows total content melt C-activity lowered. Despite offers promising reconciliation set molecular dynamics observations, this still suffers uncertainties when extrapolated In particular, endmember mixing properties both molten metal must be independently deciphered. enhanced stability couples fate deep such cases, solubility basal depends H-content higher than C-solubility implies an increase activity ascending convective cells ocean, which may cause saturation graphite or diamond unless Fe-metal droplets, having great C-solubility, present shallow ocean. Under certain conditions, behaviour lead via runaway process desiccation