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

Brown University, Providence RI

Investigators

Abstract

Liang EAR-0208141 During 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.