Figure 2: Chemical composition of pseudo-eutectic melts synthesized at high pressures.
From: Cosmochemical fractionation by collisional erosion during the Earth’s accretion
We report the compositions of melts generated by partial melting of an EC-like mantle at pressures between 5 and 25 GPa (yellow squares). Our data set plots are in agreement with previous results performed at 1 bar (ref. 14) (dark circles). Whereas MgO content (a) increases with pressure in the silicate melts, the concentrations of SiO2 (b) and Al2O3 (c) decrease. Sharp changes of the liquid compositions occur when the sample encounters phase transformations (shown with the grey arrows), in particular, with the disappearance of clinopyroxene (Cpx) at 15 GPa (vertical lines in d and f) and simultaneous disappearance of majorite (Maj) and appearance of bridgmanite (Bg, the MgSiO3 perovskite; vertical grey areas in d–f) at 24 GPa.
