Starting thermo-mineralogical models. (a) Model for the southern Cascadia subduction system. Orange-shaded area represents the cold part of the forearc mantle within which the serpentine mineral antigorite is stable. The crustal thickness of the upper plate is 30 km. The isotherms are plotted in 100°C intervals starting with the 100°C isotherm. The inclined dashed line is the top of the slab. See text for other details. (b) Starting slab-gap model showing the finite element grid in the slab and asthenosphere with an initial contact temperature of 1,100°C.