On the solubility of alumina in otfthopyroxene coexisting with olivine and spinel in the system MgO–Al₂O₃–SiO₂

抄録

The solubility of alumina in orthopyroxene coexisting with spinel and forsterite has been discussed using a simple mixing model of orthopyroxene and it was revealed that the recent experimental results in MgO–Al₂O₃–SiO₂ system (MacGregor, 1974) do not agree with the model. Reexamination of the system gave the results which are in good agreement with thermodynamically calculated alumina solubility in orthopyroxene and indicated that, in the spinel-stability field, it is not sensitive to pressure.