Fig. 12

a P–T diagram calculated from the bulk composition extracted from the quantitative map (Fig. 10e, f). Mg# isopleths of olivine are in blue and wt%-isopleths of olivine in green. b T-X phase diagram calculated for a fixed pressure of 2.5 GPa varying only the Al₂O₃ content from Fig. 10f and assuming H₂O saturation. The light blue dot marks the bulk Al₂O₃ content from the map extending the phase diagram to double the content 0.0–3.32 wt%. The red lines indicate the Al# numbers, Al/8 a.p.f.u