A comprehensive redesign of the piston-cylinder apparatus has enabled the PI to reach pressures of at least 8 GPa. The new capabilities will be exploited by experiments in three areas: 1. An accurate phase diagram in the Mg2SiO4 - Fe2SiO4 system 2. It has been predicted that the site environment of Si and A1 in silicate liquids changes as a function of pressure. The extended range piston cylinder is capable of reaching the pressures at which these changes have been predicted to occur, and run products can be analyzed by MASS NMR. This should greatly improve our understanding of magma visosities and densities. 3. Calibration of two well-known geobarometers will be carried out in the appropriate pressure range. All of these studies will enhance our understanding of the environment in the mantle and of how magma is generated in the mantle.
