Thermodynamics of multicomponent systems containing several solid solutions
Thermodynamics of multicomponent systems containing several solid solutions (in Thermodynamic modeling of geological materials; minerals, fluids and melts, I. S. E. Carmichael (editor) and H. P. Eugster (editor))
Reviews in Mineralogy (1987) 17: 71-95
A thermodynamic database has been developed for calculation of subsolidus equilibria in the system Na (sub 2) O-FeO-CaO-MgO-Al (sub 2) O (sub 3) -SiO (sub 2) . This is particularly useful for the calculation of phase relations outside the P-T range where experiments can be performed on a laboratory time-scale. Comparison with Green & Ringwood's experimental data on the gabbro-eclogite transformation demonstrates that the appearance and disappearance of phases in mafic compositions can be calculated with some confidence. Eclogite appears not to be stable in continental crust of normal thickness. Comparison of calculated phase compositions with those observed in mafic granulites at approx 7.5 kbar and 725 degrees C confirms the general validity of the database and solution models derived.