PHASE CONVECTION AND CHEMICAL DIFFERENTIATION DURING ALTERATION OF MAGMATIC MATERIAL

Chemical and thermal evolution of two-phase melt-crystal mixture have been studied taking into account the presence of conjugated intrachamb er processes of melting, crystallization, separate phase moving. In th e system considered the upward melt filtration, downward crystalline n etwork transfer and its partial melting at the low boundary and crysta llization at the upper one resulted in formation of closed material ci rculation i. e. the phase convection cell. The chemical differentiatio n in such a system proved to behave as a concentration leaps (chemical shocks) spreading from the system boundaries. This behavior leads to full differentiation of the altered material into the end-member phase s and nonvariant mineral associations.