MAGMA MIXING USING GEOCHEMICAL DATA FROM THE TRANS-MEXICAN VOLCANIC BELT

Past studies have suggested that the formation of intermediate magma is the result of felsic and magma mixing. In this research, the program MELTS for Excel was used to interpret geochemical data from the Trans-Mexican Volcanic Belt, to determine in what thermodynamic conditions felsic and mafic magmas meet and mix to form intermediate magma. The Trans-Mexican Volcanic Belt (TMVB) is a very complex convergent margin, mainly controlled by two oceanic plates. It origin is still being study. The thermodynamic conditions taken in consideration for this research were temperature (800˚-1200˚ C) and viscosity. Three graphs were made to show the possibilities of magma mixing in this volcanic belt. The first was a crystal fraction graph, showing the recrystallization process of the mafic and felsic samples of the Trans-Mexican Volcanic Belt. The second graph was the melts viscosity with no crystals, and the last graphic showed the magma viscosity with crystals included. The last graphs showed a crossover of the felsic and mafic magma composition. However, the temperatures in which these magma compositions met were in very high temperatures (1172˚ C- 1196˚ C). Magma mixing can occur, but not in such high temperatures. Studying magma mixing is important because it could be the result of the intermediate magma making.