FORMATION OF REACTION GARNETS DURING MELTING OF THE MGCO3-CACO3- NAALSIO4-SIO2 SYSTEM AT 7.0 GPA

Abstract

The formation and evolution of deep-seated carbonatite magmas under the PT conditions of diamond formation represent complex physicochemical processes that incorporate multicomponent silicate material of mantle peridotite, strongly compressed carbonate melts, and CO2 fluids, which possibly represent the products of multiphase plume differentiation. Mobile low-viscosity carbonatite magmas belong to the chemically active forms of deep-seated matter of the dynamic mantle. It has been suggested that the carbonatite magmas contribute to mantle metasomatism as “carbonatite fluids”.