9614423 Mysen The principal objective of the proposed research is to investigate in-situ at high temperature and pressure (crustal and upper mantle conditions) the chemical structure of hydrous silicate melts and associated hydrothermal fluids as a function of temperature, composition, and pressure. This pilot project will focus on a systematic study of water-saturated potassium silicate melts and coexisting aqueous fluids. The project will involve complementary studies including (1) in-situ Raman spectroscopic measurements of both the melt and aqueous phase, and (2) phase equilibrium experiments and necessary analytical examination to determine the exact compositions of the two phases. Spectroscopic studies will be performed using externally- heated diamond-anvil cells which are capable of being used to temperatures of 1000oC and pressures in excess of 2.5 Gpa.
