In situ determination of crystal structure and chemistry of minerals at Earth's deep lower mantle conditions

Recent advances in experimental techniques and data processing allow in situ determination of mineral crystal structure and chemistry up to Mbar pressures in a laser-heated diamond anvil cell(DAC),providing the fundamental information of the mineralogical constitution of our Earth's interior.This work highlights several recent breakthroughs in the field of high-pressure mineral crystallography,including the stability of bridgmanite,the single-crystal structure studies of post-perovskite and H-phase as well as the identification of hydrous minerals and iron oxides in the deep lower mantle.The future development of high-pressure crystallography is also discussed.

地球下地幔矿物结构和热力学参数的研究进展与展望

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。