Phase Equilibria in the Systems Consisting of Px, Ol and Gt.

本文的研究结果表明，具有辉石、石榴石、橄榄石等组成的高压矿物对阐明地幔结构具有指示意义。本文的研究结果如下：1.Fo(Mg_2SiO_4)-Py(Mg_3Al_2Si_3O_1)体系，在8 Gpa和13.5 Gpa，2025-2200ﾟC下进行了实验，得到了共晶点(Fo+Py+液体)和包晶点(Fo*方镁石+液体)。实验是在8-15 Gpa下进行的。存在一个共晶点(Fo+Px+Liquid)，并随着压力的增加向Fo移动。用Saimon方程P=[(T/1664.5)^&lt；5.17(Sy.+-.])0.04&gt；-1测定了Di在22 Gpa以下的压力依赖关系：Fo-Py-en(Fo_&lt；54&gt；Py_&lt；13&gt；En_&lt；33&gt；.IV.The)体系，15 Gpa的临界点在2200(Sy.+-.)20ﾟC；在7 GPa时的共晶点在1170(Sy.+-.)20ﾟC和Fo_&lt；30&gt；Py_&lt；25&gt；Di_&lt；45&gt；随着压力的增加向Fo移动。橄榄石(Fo_&lt；90&Gt；Fa_&lt；10&gt；10&gt；)在18-23 Gpa时不一致地熔化成“B”相+液体，而改性尖晶石则在18-23 Gpa时熔化成wusite+液体。结果表明，E相是俯冲盆地H2O储集层的候选者，B相、F相和转换带下部和下地幔上部的水镁石是H2O储集层。

The results of the present study show that the high pressure minerals having the compositions of pyroxenes, garnet, olivine are indicepensable in elucidating the structure of the Earth's mantle.The results obtained in the present study are as follows :I.The system Fo (Mg_2SiO_4) -Py (Mg_3Al_2Si_3O_<12>) ; The experiments have performed at 8 and 13.5 GPa and 2025-2200ﾟC.An eutectic point (Fo+Py+liquid) and a peritectic point (Fo*periclase+liquid) are present.II.The system Fo-Di (CaMgSi_2O_6) ; The experiments have made at 8-15 GPa. An eutectic point (Fo+Px+liquid) is present and moves towards Fo with increasing pressure. Pressure depencdence of Di were also determined up to 22 GPa with the Saimon equation P=[(T/1664.5) ^<5.17(]SY.+-.])0.04>-1].III.The system Fo-Py-En (MgSiO_3) ; An entectic point at 15 GPa lies at 2200(]SY.+-.])20ﾟC and Fo_<54>Py_<13>En_<33>.IV.The system Fo-Py-Di ; An eutectic point at 7 GPa lies at 1170(]SY.+-.])20ﾟC and Fo_<30>Py_<25>Di_<45> and moves towards Fo with increasing pressure.V.The system Fo-Fa (Fe_2SiO_4) ; Phese equilibrium diagam at 8 GPa has been studied. Olivine (Fo_<90>Fa_<10>) melts incongruently into "phase B "+liquid and modified spinel into wustite+liquid at 18-23 GPa.IV.The system MgO-SiO_2-H_2O ; The experiments have been made at 11-23 GPa. The results obtained suggest that phase E is a candidate of H_2O reservior in the subducting sulab and the superphase B,the phase F,and the brucite in the lower part of the transion zone and the upper part of the lower mantle.