地球深部物质科学——在静高压大腔体实验研究方面的某些进展

ON MATERIAL SCIENCE OF THE EARTH'S INTERIOR

介绍近年来使用静态超高压大腔体实验技术 ,在模拟地球内部的高温高压条件下 ,对地球物质进行的若干物理和化学性质的实验研究。高压同时高温条件下多种岩石样品的弹性波速就位测量揭示出物质的声软化现象和振幅效应 ;高温高压下陨石和岩石的熔融结晶实验发现了陨石硅酸盐相的不混溶现象以及玄武岩熔体结构的变化 ,在玄武岩转变为榴辉岩的实验中观测到了刚玉相 ;在高温高压水的实验中 ,发现了冰 Ⅶ 的亚稳相和熔融前效应以及超临界水及其稀溶液的一些新性质。这些实验结果为探索地球深部物质的性质和状态以及迁移和演化提供了新的依据。

Some advances in the experimental studies of the physical and chemical properties of the Earth's materials carried out in the Laboratory of Material Science of the Earth's Interior in recent years are reported.In these experiments, the multi\|anvil apparatus is used to simulate high pressure\|temperature conditions of the Earth's interior. The compressional wave velocities for various rocks have been measured under simultaneous conditions of high pressure and high temperature. The softening and amplitude effects were observed during the measurement of the compressional wave velocity. In the melting experiments of chondrite, the immiscibility of two different silicate melts(one is rich in SiO 2 and the other in MgO) is identified by the microscopic study and probe analysis. Based on the melting experiment of the alkaline basalt at 1 0～3 5GPa and 1400～1700℃,the relationship between structures of the alkaline basalt melts and pressures is discussed. In addition, it is found that the corundum can crystallize from alkaline basalt melts when the cooling rate of the melts is very fast. Such a phenomenon has not been noted or described in previous studies. The thermal and electrical properties of water and electrolytic aqueous fluids are determined at high pressure and high temperature. Some new phenomena are discovered, such as the metastable phase of ice VII , pre\|melting effect of ice,etc.The results are new data for elucidating the characteristics and evolutions of the materials in the Earth's interior.