【摘要】 下地幔从660 km到2 891 km深度,占据整个地球质量的49.2%并处于极端高温高压的状态。在下地幔相应的温度压力条件下研究主要构成矿物的物理性质,尤其是结构、密度和波速,是理解下地幔结构、物质组成以及动力学过程的关键。通过回顾过去30年高温高压矿物学实验对下地幔矿物,包括布里基曼石、铁方镁石、Ca-钙钛矿以及硅酸盐—后钙钛矿结构和热力学状态方程的重要研究进展,探讨温压条件变化、成分变化以及Fe自旋变化对这些下地幔矿物(相)密度和体波波速的影响,指出现有研究结果的不足和需要解决的问题,并对未来的研究方向提出展望。更多还原

【Abstract】 Lower mantle,ranging from 660 km to 2 890 km depth,occupies 49.2% of the Earth by mass and is at extremely high pressure and temperature conditions. Experimental studies on the physical properties of the lower mantle minerals,particular the structure,density,and sound velocity,etc.,are important to understand the structure,composition,and dynamic behavior of the region. Here we summarize the recent experimental results on the structure and thermal equation of states of the lower mantle minerals,including bridgmanite,ferropericlase,CaSiO₃-perovskite,and silicate post-perovskite,and discuss the effect of pressure,temperature,composition,and Fe-spin transition on the density and bulk sound velocity of those minerals. This review aims to provide new insights into the lower-mantle structure and chemistry and help to understand the observed velocity anomalies in the lower mantle.更多还原