P-T Stability of Phlogopite, K-Richterite and Phengite, as a Source of Potassium in the Mantle - Origin of Potassium-rich Silica-deficient Igneous Rocks - page 373

between 300 ° C and pressures between 1.5 and 3.0 GPa. The ascending potassium-

rich fluid should penetrate the overlying mantle and metasomatize it. After termi-

nation of the subduction process, heating of this mantle material, previously cooled
by the subducted lithosphere, could lead to the formation of a high temperature
potassium-rich magma.