Extended Data Fig. 9: High-angle annular-dark-field images of the samples of Ca-pyrolite (a) and komatiitic composition (b).

a,b, The yellow boxes indicate the areas where chemical compositions were measured, which are presented in Fig. 2b, d. a, Chemical compositions were analysed at the bottom left of the sample where the thickness was smaller. The presented area of the sample shows texture consistent with heating centre, that is, well crystallized bridgmanite and ferropericlase. b, Chemical compositions were analysed at the top area of the sample. The Ca-rich bridgmanite matrix is nearly indistinguishable from the unheated glass since the Ca-rich bridgmanite matrix takes roughly 95 vol% of the sample. However, the well crystallized grains of other phases (Al₂O₃ and SiO₂) show that the area is well heated.