Figure 6
Diagrams showing the relationship between the final melting temperature of the clathrate and the salinity (uncorrected for the presence of clathrate) of type 2 fluid inclusions in rodingitized diorite (A; samples Dior-1, -2), rodingitized granite (B; sample Gran-1b), rodingitized slate (C; samples Slate-1b, -2), and in vesuvianite (D; sample Ves-1). Primary type 2 fluid inclusions form three distinct populations: 1) Low density type 2a fluid inclusions characterized by high salinity and low final clathrate melting temperatures, 2) high density type 2b fluid inclusions showing a wide range of salinities and elevated final clathrate melting temperatures, and 3) low density and low salinity type 2c fluid inclusions found in vesuvianite. Also shown on the diagrams are isobars at pressures of 25, 50, 100, 150 and 200 bar for the system CH4-NaCl-H2O calculated using program CURVES [30]. Filled symbols represent data for primary fluid inclusions and open symbols represent data for secondary fluid inclusions. Refer to the text for a detailed discussion.