Experimental Studies on Chemical Structure of the Deep Mantle and Its formation Processes.

在项目期间，利用多砧式高压装置对土质材料进行了试验研究，取得了以下结果：8 GPa以上地幔矿物的相关系：确定了(1)辉山石-钙长石-透辉石，(2)透辉石-顽辉石，(3)辉山石-钙长石体系的相平衡图。阐明了部分熔融液组成的压力依赖性和存在的矿物的熔融行为。核心材料的相变和相平衡：(1)铁的相变由我们实验室开发的电阻法测定。(2)在8 gpa下测定了Fe-Fes体系的相平衡。3、核幔物质之间元素分配：确定了地幔矿物、硅酸盐熔体和金属铁之间的部分元素分配，并根据实验数据检验了这些元素的丰度与核幔平衡模型的关系。用x射线衍射分析原位观察MgSiO_3的转变：在20 ~ 27 gpa时测定了斜辉石结构- mgsio_4尖晶石+辉长石-钛铁矿结构的转变。火星内部模型；对估计的火星地幔组成进行了高压-高温实验，并根据实验结果提出了火星内部的结构模型。高压下橄榄岩熔体的密度：研究了橄榄岩和橄榄岩熔体的压力依赖性，结果表明橄榄岩和富铁橄榄岩熔体之间的密度不可能交叉。

Experimental studies on the earth matrials have been performed using the multi-anvil type high pressure apparatus with the following results during the term of project.1. Phase relations among the mantle minerals above 8 GPa : Phase equilibrium diagrams have been determined for the system (1) forstbrite-anorthite-diopside, (2) diopside-enstatite, and (3) forsterite-pyrope. Pressure dependence of the composition of the liquid produced by partial melting and the melting behavior of the minerals present were elucidated.2. Transitions and phase equilibria of the core materials : (1) Transitions of Fe were determined by the electric resistance method developed in our laboratory. (2) Phase equilibria of the system Fe-Fes were determined at 8 GPa.3. Partitioning of elements between core and mantle materials : Partitioning of some elements between mantle minerals, silicate melts, and metal iron above 10 GPa was determined, and the relationships between abundance of these elements and core-mantle equilibrium odel were examined on the basis of the experimental data.4. In-situ observation of MgSiO_3 transition by X-ray diffraction analysis : Transition of clinopyroxene structure - Mg_2SiO_4 spinel +stishovite - ilmenite structure were determined at 20 - 27 GPa.5. Martian Interior model ; High pressure-high temperature experiments were carried out on a estimated martian mantle composition and a structure model of the martian interior were presented, based on the experimental results.6. Density of peridotite melt at high pressures : Pressure dependence of forsterite and peridotite melt were examined with the result suggesting that density cross over between forsterite and Fe-rich peridotite melt is not probable.