Экспериментальное изучение эклогитовой системы (гранат-омфацит) при 4. 0-7. 0 ГПа: моделирование условий формирования алмазоносных эклогитов

Phase relations in a multi-component eclogite system garnet-omphacite and some its binary joins were studied at pressures 4.0 – 7.0 GPa. Experimental study of pseudo-ternary system omphacite-pyrope (+32 mol.% grossular) almandine (+32 mol. % grossular) within its polythermal section omphacite-pyrope 15almandine 53grossular 32 at pressure 7.0 GPa showed the cotectic melting of the garnet-omphacite assemblage, whereas solidus temperature was about 1450 0С. This value is higher than the calculated temperatures for eclogite nodules from kimberlite pipes. This fact implies a fluidized nature of the eclogite magmatic systems in the mantle. The constructed phase diagrams allow the interpretation of physical-chemical conditions for formation and evolution of eclogite parageneses using, in particular, the crystallization features of garnet as the major eclogite phase.