Anatexis

ANATEXIS (from the Greek word "anatexis", which means "melting" * EN: anatexis, refusion; DE: Anatexis; FR: anatexix; ES: anatexix; RU: анатексис) is the set of the processes, which are leading to the melting of the solid rocks, and to their transformation into the magma. The classical idea about the anatexis has been developed by the Finnish geologist Y.I.Sederholm (1907).

Anatexis proceeds during the combination of the processes of the high temperature metasomatic replacement of the original rocks, and of the melting-out of the low-temperature "eutectic" melts from the altered rock. According to the ideas, which are developed by the Soviet scientist D.S.Korzhinsky (1972), anatexis proceeds during the magmatic replacement of various rocks under the impact of the deep transmagmatic solutions, during which the rocks are subjected originally to metamorphism, then to the high-temperature metasomatism (granitization), and finally are transformed into magma.

The granitoid anatexis proceeds within the limits of the continental crust for the rocks, which are containing feldspar and quartz, at the temperature of 665-740 degrees Celsius, at the depth of 10-20 kilometres. Sometimes granitoid anatexis is noted within the exocontacts of the intrusions within the basic magma. At the base of the lithosphere or within the asthenosphere, under the conditions of the mantle, anatexis proceeds with the formation of the basaltic, andesitic, and alkaline magmas.