PHASE-EQUILIBRIA IN CARBONIC SYSTEMS, AND THEIR APPLICATION TO FREEZING STUDIES OF FLUID INCLUSIONS

Addition of CH4 to CO2 lowers the temperatures at which phase changes occur with respect to those in the unary system CO2. At high density and high {Mathematical expression} a melting interval of solid CO2 can be expected. Rearrangement of currently available theoretical and experimental data permits bulk compositions of carbonic fluid inclusions to be determined from the final melting temperature of CO2 and the degree of filling at that temperature. Homogenization temperatures of CO2-CH4 inclusions can be expressed in terms of equivalent CO2-densities, permitting estimates of P-T relations using isochores in the unary system CO2. © 1979 Springer-Verlag.