Fig. 5
a Silicon content of Mercury’s core assuming metal-silicate equilibration at pressures prior to mantle stripping. Points show \(X^{\text {met}}_{\text {Si}}\) for core formation at specified pressure for different metal S content (1, 2, 5, and 7 wt%). Horizontal dashed lines show the mean for each assumed core sulfur content. b Calculated δ30Sim for fractionation at various temperatures corresponding to the depth of a magma ocean and growing core mass on proto-Mercury. Colored bands show mean and ± 2σ uncertainties for δ30Si for major chondritic meteorite classes. Points show predicted fractionation in silicate for ∼ 2 wt% S content if δ30Sib corresponds to enstatite or ordinary and carbonaceous classes, and would be the predicted δ30Si for meteorites derived from fragments of Mercury’s stripped mantle. All estimates are ∼ 0.1‰ higher than their chondritic parents’ means. Circles and squares are from experimentally determined fractionation factors of Shahar et al. (2011) and the composite estimate (see the “Methods” section), respectively