[SIT22-P27] Phase relations of MgSiO3-FeSiO3 system up to about 60 GPa and 2300K using multianvil apparatus with sintered diamond anvils
Keywords:bridgmanite, high temperature generation, sintered diamond anvil
Based on the newly developed high pressure and temperature techniques, we studied detailed phase relations in the system MgO-FeO-SiO2 using KMA with SD anvils at pressures up to 61 GPa at a temperature of 2000 K. Synthetic pyroxene samples with chemical compositions of (Mg0.4Fe0.6)SiO3 and FeSiO3 were used as the starting materials. Both quench experiments and in situ X-ray observations were adopted to constrain the phases present. Single-phase bridgmanite and an assemblage of wüstite + stishovite were formed in the MgSiO3-rich and FeSiO3-rich regions, respectively, under the present pressure and temperature conditions of up to ~60 GPa, which is generally consistent with the phase relations in the earlier studies. We found the solubility of FeSiO3 in bridgmanite increases almost linearly with increasing pressure from Fe* (Fe/Fe+Mg) = 0.19 for 27 GPa to 0.38 mole for 60 GPa at 2000 K. The iron content in wüstite also significantly increases from Fe* = 0.68 for 27 GPa to 0.96 for 60 GPa.