Fig. 26

Scatter plot depicting the minimum entrapment temperature and calculated pressure conditions for H₂O–CO₂–NaCl fluid inclusions. The linear plots are lines of constant density (isochores) for the average density plus/minus one standard deviation for the H₂O–NaCl inclusions with the density listed in g/cm³. The dashed lines are hydrostatic (H) and lithostatic (L) thermobaric gradients for thermal gradients between 30 and 80 °C/km. The shaded areas define the statistical range (~1σ) of P–T conditions during which the H₂O–NaCl fluids were trapped. The peak temperature of the Yuli Belt is 550 °C (Kouketsu et al. 2019) based on RSCM, which we assume was the maximum entrapment temperature for the fluid inclusions. The maximum entrapment temperature for the southern site was constrained at 450 °C using RSCM (Beyssac et al. 2007). The depth was calculated using an overlying rock density of 2.7 g/cm³