Metamorphic minerals and mineral assemblages record information about the intensive conditions temperature, fluid pressure, oxygen fucacity, etc. which they experienced during metamorphism. Laboratory experiments are required to quantify these conditions. My research effort has two principle objectives: (1) to experimentally locate, in P(fluid)-T-X(CO2) space, the positions of key metamorphic equilibria in the model chemical system CaO-MgO-A12O3-SiO2-H2O-CO2, and (2) to use the experimentally located equilibria to refine the thermochemical parameters for selected rock-forming minerals which occur in the model system. The latter objective is pursued in cooperation with Rob Berman of the Geological Survey of Canada.