Projection of normative composition of liquids. Projection of normative composition of liquids (aphyric lavas and groundmasses of porphyritic lavas) on the pseudo-ternary diagram after the schemes of Tormey et al. (1987) and Grove (1993). The olivine-plagioclase-clinopyroxene cotectic at 0.1 MPa is from Walker et al. (1979); the olivine-plagioclase-clinopyroxene cotectic at 200 MPa is from Berndt et al. (2005); and the orthopyroxene-plagioclase-clinopyroxene cotectic at 400 MPa is from Hamada and Fujii (2008). The addition of H2O expands the stability field of clinopyroxene at a given pressure, resulting in a shift in the cotectic curve toward the olivine apex.