9315918 Zhang This project proposes to explore further the potential of applying homogenous reaction kinetics to geospeedometry. The kinetics of different homogeneous reactions for various thermal histories will be examined systematically and quantitatively with theoretical analysis and numerical simulations. The effect of parameters such as activation energies of forward and backward reactions, pre-exponential factors, cooling rates, and diffusion on the kinetics of different reactions during cooling will be quantitatively evaluated. The kinetics of the interconversion of hydrous species in rhyolitic glasses will be characterized experimentally. The variation of speciation with time will be used to extract reaction rate coefficients and reaction mechanisms, which will enable scientists to constrain the thermal history of volcanic glasses and understand more completely volcanic processes.
