Commingling of Contrasted Magmas in Various Geodynamic Settings

Authors : Bernard PLATEVOET, Jean BEBIEN, Edilene GOMES

Pages : 119-132

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Three acid-basic associations taken in various geodynamical settings are studied: the gabbro-granite association of Porto insert ignore into journalissuearticles values(Corsica);, the associations of the Guevgueli insert ignore into journalissuearticles values(Greek Macedonia);, and the associations of the Piracaia complex insert ignore into journalissuearticles values(Brazil);. The diversity of field relations, the degree of mingling, the origins of the melts are debated for each association, using petrological and geochemical tools for each acid-basic association. An origin by hybridization is assumed for the intermediate rocks of the Porto association, it is tested by numerical calculation. Then, we focus on the mixing process between the comagmatic components. Mixing of melts may have happened by thorough mingling and chemical diffusion under disequilibrium conditions attested by textural characters of the hybrid rocks. The mixing between the contrasted melts can not be complete, it appears that the mean effective ratio between the two mixed components insert ignore into journalissuearticles values(the effective mixing ratio); in the hybrids is weak compared with the acting volume of mafic magma during the magmatic brecciation, it may be the result of the difference between thermal and chemical rates.
Keywords : Turkish J Earth Sci, 7, 1998, 119 132 Turkish J Earth Sci, vol 7, iss 3