Vaporization coefficients of oxides contained in the melts of Ca-Al-inclusions in chondrites

Based on the analysis of theoretical and experimental data, the following vaporization coefficients are suggested for crystalline oxides contained in Ca-Al-inclusions in chondrites: 0.66 ± 0.15 for CaO, 0.50 ± 0.20 for MgO, 1.00 ± 0.20 for FeO, 0.33 ± 0.02 for Al 2 O 3 , 0.23 ± 0.02 for TiO 2 , and (2.2 ± 0.3) × 10 −2 for SiO 2 . For vaporization from liquids, the coefficients of these oxides found in the Ca-Al-inclusions are equal to one, which is confirmed by the consistency of experimental data and thermodynamic calculations for changes in the composition of multicomponent oxide melts during vaporization.