Developments and Applications of Self-Consistent Models of Crystal-Melt Interaction in Molten and Partially Molten Silicates

在向地表或地下储集区迁移的过程中，地球内部深处产生的岩浆不可避免地会与围岩及其寄主的多孔晶体基质发生反应。这项研究是对地球上地幔和下地壳中晶体-熔体和岩石-熔体反应动力学的实验室和数值研究相结合的结果。该项目的实验室部分涉及对地幔岩石和矿物(橄榄石、辉石和石榴石)在安山岩至苦橄岩成分的熔融硅酸盐中的溶解研究。晶体-熔体相互作用的理论和数值研究将集中在两个长度尺度上：颗粒尺度和连续尺度。一旦与实验室实验相结合，对颗粒尺度过程的研究将有助于我们确定晶体-熔体反应机理，确定反应速率的参数，并改进实验设计。使用实验室校准的反应速率和热力学相关系的连续尺度反应流动模型将使我们能够更好地限制熔体在上地幔和下地壳中的输送和熔岩反应。对晶体-熔体相互作用的实验室和理论研究相结合，也将使我们能够开发新的方法，可以用来估计晶体和熔体中的岩浆上升速度和扩散系数。将建立一个镁铁质成分的硅酸盐熔体和晶体中的化学扩散数据库。这个数据库将被整合到布朗大学PI教授的研究生和本科生地质学课程中。

LiangEAR-0208141During their migration towards the surface or subsurface storage areas, magmas generated deep in the Earth interior will inevitably react with the wallrocks and their host porous crystalline matrices. The proposed research is a combined laboratory and numerical study of the kinetic of crystal-melt and rock-melt reaction in the Earth upper mantle and lower crust. The laboratory part of the project involves dissolution studies of mantle rocks and minerals (olivine, pyroxenes and garnet) in molten silicates of andesitic to picritic compositions. Theoretical and numerical studies of crystal-melt interaction will focus on two length scales: grain scale and continuum scale. Once coupled with laboratory experiments, studies of grain scale processes will help us to identify crystal-melt reaction mechanisms, parameterize reaction rates, and improve experimental design. Continuum scale reactive flow models using laboratory calibrated reaction rates and thermodynamic phase relationships will allow us to better constrain melt transport and melt-rock reaction in the upper mantle and lower crust. A combined laboratory and theoretical study of crystal-melt interaction will also allow us to develop new methods that can be used to estimate magma ascent rate and diffusion coefficients in the crystals and melts. A database for chemical diffusion in silicate melts and crystals of mafic compositions will be constructed. This database will be integrated into the graduate and undergraduate geology courses that are taught by the PI at Brown University.