Fig. 7
FeO–MgO–SiO2 and Cr2O3–Al2O3–SiO2 diagrams illustrating the calculated compositions of spinel Spl2 coexisting with A and B: MgAlChl2 (Fe0.2Mg9.3Cr0.1Al4.9Si5.5O20(OH)16) and C and D: FeCrChl2 (Fe0.5Mg9Cr1Al4Si5.5O20(OH)16), and associated KDs for WR2a (MgO loss, reddish, collinear with WR0) and WR2b (silica addition, blue). The compositions of initial and readjusted (eq. 10) spinel and olivine (Spl0, Ol0, Spl1 and Ol1) are shown for reference. See text for details.