Fig. 1. Illustration of mantle melting due to decompression (a), heating
(b) and release of water (c). Solidus temperature for peridotite (thick
curve in a), b) and c)) is taken from Takahashi (1986). Thin curves give
typical geotherms with a potential temperature Tp =1400 °C. In a) upwelling
and decompression may be due to 50% thinning of the lithosphere. In b)
the mantle temperature is increased by 200°C by e.g. the arrival of
a plume. In c) the solidus is decreased due to 2.9 wt% water (Inoue and
Sawamoto, 1992). The thin dashed curve give the saturated wet solidus temperature.