硅酸盐熔体的物理化学性质研究进展及其应用

硅酸盐熔体具有高度的物理和化学活性, 是地球乃至其他类地行星内部物质和能量迁移的重要载体. 它们在地球内部层圈形成和演化的岩石学和动力学过程中发挥了关键作用. 充分了解高温高压条件下各种成分硅酸盐熔体的物理化学性质, 是正确认识与壳幔部分熔融相关的各种地质现象(如深部岩浆作用和火山喷发)的先决条件. 硅酸盐熔体自身的物理化学性质分为热力学性质(包括热力学状态函数和均相反应平衡常数)与动力学性质(包括迁移性质和均相反应速率常数). 针对硅酸盐熔体性质的研究, 近年来在高温高压实验和分析技术、计算方法(特别是第一原理分子动力学模拟)、理论模型以及熔体宏观性质与微观结构之间联系等方面都取得了很大进展. 通过与地球物理和地球化学观测的结合, 熔体性质领域的研究进展显著改进了我们对地球内部状态和地质过程的理解. 本文综述了硅酸盐熔体物理化学性质研究的成果和现状, 阐释了一些具有重要意义的应用实例, 并展望了该领域未来的研究趋势.

Advances and application in physicochemical properties of silicate melts

Silicate melts, physically mobile and chemically active, are a crucial means for the transfer of matter and heat in the Earth and plausibly other terrestrial planets. They have played a key role in petrologic and geodynamic processes throughout the formation and evolution of Earth’s internal spheres. To understand geological phenomena related to partial melting of the crust and the mantle (such as deep magmatism and volcanic eruption), it is a prerequisite to gain good knowledge of the physicochemical properties of various silicate melts at high temperature (HT) and/or high pressure (HP). Physicochemical properties of silicate melts fall into two categories, namely thermodynamic properties (including thermodynamic state functions and equilibrium constants of homogeneous reactions) and kinetic properties (including transport properties and rate constants of homogenous reactions). In the study of melt properties, major progress has been made in recent years with respect to HP-HT experimental and analytical techniques, computational methods (in particular simulations using first-principles molecular dynamics), theoretical modeling, as well as the relationship between the macroscopic properties and microscopic structure of silicate melts. Combined with geophysical and geochemical observations, the advances in the study of melt properties have substantially improved our understanding of the conditions and processes in the Earth’s interior. This paper presents a review on the contemporary developments in this field, some examples of important application, and a discussion of future directions.