Figure 8
Ternary diagram showing the compositions of type 2b fluid inclusions (solid circles) in the system H2O-NaCl-CH4. The compositions were calculated with the program CURVES [30] using visual estimates of the volume fraction of aqueous solution in the inclusions. Dashed lines represent the solvus in the system at various pressures and temperatures (calculated using GEOFLUIDS model 1 [32,33,35-37]) along a geotherm of ~0.12°C/bar. The trend in inclusion fluid compositions suggests mixing between two fluids of contrasting salinity. See text for a detailed discussion.