9706031 Liang This one-year pilot project is a combined laboratory and numerical study of crystal growth and dissolution in the ternary CaO-Al2O3-SiO2 system. The study will address two major questions: (1) the role of coupled chemical diffusion in crystal growth and dissolution in molten silicate melts, and (2) the assumption of local thermodynamic equilibrium at the crystal-melt or mush-melt interface. The laboratory experiments will involve material synthesis, determination of liquidus surfaces, diffusion controlled dissolution of single crystals and polycrystalline materials, and diffusion controlled dissolution of a crystal-melt mush, all at 1500oC and 1 GPa. This study will set the stage for future studies of dissolution in more complicated systems and also for studies of free convection assisted dissolution. Such studies have the potential to elucidate large scale structure and dynamics of magma chambers, small scale igneous textures, and models for mineral growth rates.
