A modified Redlich-Kwong equation of state is used to calculate the solubility of CO2 in methane at various temperatures and pressures. From the solubility of CO2 in CH4 at the triple point and at final melting (Th < Tfm), and the molar volume of solid CO2, the volume of solid at the triple point, and the molar volume of the inclusion can be calculated using a mass balance. The pressure at the melting point is calculated from the equation of state. The algorithm predicts composition, molar volume, pressure at final melting and the isochor pressure (for a given temperature of trapping) for CO2-CH4 fluid inclusions for the case Th < Tfm, given Th, Tfm and experimental data on Ph and dco2 (solid) at Th.
ASJC Scopus subject areas
- Geochemistry and Petrology