dc.description.abstract | This experiments verifying the existence of hot spots on the surface of sliding solids (Bowden and Thomas, 1954) are mentioned, along with suggestions as to how much hot spots could be caused on the surface of minerals in rocks during tectonic movements. It is suggested that hot spots may be capable of stimulating the recrystallization of metastable phases, thereby allowing local areas, e.g. shear zones, to achieve thermodynamic stability and appear as zones of different metamorphic facies than their surroundings (e.g., chlorite schist zones in hornblende schist). It is also suggested that hot spots may provide the energy necessary to enable assemblage to recrystallize and differentiate assemblages of lower free energy, attention being drawn especially to how the total interfacial or grain boundary free energy (De Vore, 1959) might be lowered by recrystallization and local differentiation stimulated by high surface temperatures. | |