PHASE DIAGRAM OF CaO–Al₂O₃–SiO₂ SYSTEM AT PRESSURES OF UP TO 40 kbar Available to Purchase

On the basis of known experimental data, the topology of a phase diagram of the CaO–Al₂O₃–SiO₂ system has been analyzed at pressures of up to 40 kbar. The main phase relationships are experimentally verified and refined, and stability fields for such phases as wollastonite, larnite, rankinite, anorthite, gehlenite, grossular, Ca-tschermakite clinopyroxene, calcium aluminates, etc. are characterized. The paper considers the location of univariant lines and invariant points in the temperature-pressure coordinates. A phase diagram for the CaO–Al₂O₃–SiO₂ system is constructed, which includes all main phase relationships at pressures of up to 40 kbar. From the topologic regularities of the phase diagram of this system, the character of univariant and invariant equilibria for the stability fields of grossular, Ca-tschermakite clinopyroxene, anorthite, etc. is refined. It is shown that stable associations of Ca-tschermakite clinopyroxene with quartz cannot exist. The constructed phase diagram is based only on the experimental data and serves as an internally consistent model for a phase diagram of the CaO–Al₂O₃–SiO₂ system at pressures of up to 40 kbar. It may be a base for refining phase relationships in this system and for practical use in petrology and materials technology and on thermodynamic modeling.