Thermodynamic data for phases in the FeO-MgO-SiO2system and phase relations in the mantle transition zone

✍ Scribed by Olga B. Fabrichnaya

• Publisher: Springer-Verlag
• Year: 1995
• Tongue: English
• Weight: 914 KB
• Volume: 22
• Category: Article
• ISSN: 0342-1791
• DOI: 10.1007/bf00202773

✦ Synopsis

Based on the available experimental data on phase equilibria in the FeO-MgO-SiO2 system the mixing properties of the solid solutions (olivine, fl-and y-spinel, pyroxene, majorite, ilmenite and perovskite and magnesiowustite), the enthalpies of FeO and fictive FeSiO 3 phases with ilmenite and majorite structures have been assessed. The entropies, temperature dependance of heat capacities for fictive FeSiO 3 end-members were estimated from structural analogies. The calculated phase diagrams for Mg2SiO4-Fe2SiO 4 and MgSiO3-FeSiO 3 systems at pressures up to 30 GPa and temperatures between 1000 and 2100 K are quite consistent with the available experimental determinations except for the fine features of the phase diagram at 2073 K.