Figure 3. Schematic distribution of temperature in the lithosphere from its values at the interfaces produced by the phase transitions of the material: 1 - ice-water transition, 2 - Curie point for pyrrhotite, 3 - transition of the rock to an above-critical state; 4 - Curie point for magnetite; 5 - transition of olivine to spinel; 6 - the upper boundary of a partial melting zone in the asthenosphere.