The production of granitic melts during ultrametamorphism

Data concerning the occurrence and mineralogy of granitic rocks and migmatites indicate that granitic liquids are not generally water saturated and do not form on minimum melting curves. Experiments on the partial fusion of crustal materials containing water only in hydrated phases demonstrate that water undersaturated melts with compositional affinities to the granite family are produced at temperatures and pressures in accord with observations on the metamorphio state of migmatite terrains.