Fig. 1
From: Phase diagram and density of SiO2–H2O fluid across critical conditions
Schematic phase relations of SiO2–H2O binary system, a T–X phase diagram. The solid and dashed curves represent P1 and P2 conditions, respectively, with P1 < P2. Green curve represents the solubility of quartz in aqueous fluid (①); red curve represents the solubility of H2O in SiO2 melt (②); ③ represents the V–L–S three-phase coexistence; ④ and ⑤ represent the vapor–liquid equilibrium curves. b Critical curve, hydrous melting curve and the upper critical endpoint (UCEP). V: aqueous fluid; L: hydrous silica melt; S: solid (quartz); F: single phase fluids