Metamorphic facies and stability fields of hydrous minerals under subduction-zone conditions. Metamorphism above the coesite/quartz transition line is referred as ultrahigh-pressure (UHP) metamorphism, whereas metamorphism below the coesite/quartz transition line is referred as high-pressure (HP) metamorphism. Dashed lines denote the geothermal gradients at 5°C/km and 15°C/km, respectively, in subduction zones. Solid dark-red curves denote the wet solidi for basalt (Schmidt and Poli 1998) and granite (Holtz et al., 2001), with circles for the second critical endpoints of the basalt-water system (after Mibe et al. 2011) and the granite-water system (after Hermann et al. 2006a). Mineral abbreviations: Amp, amphibole; Chl, chlorite; Cld, chloritoid; Law, lawsonite; Zo, zoisite. Lithological abbreviations: GS, greenschist-facies; EB, epidote blueschist-facies; EA, epidote amphibolite-facies.