Magma hybridization and crystallization in coexisting gabbroic and granitic bodies in the mid-crust, Akechi district, central Japan

Abstract Petrological and geochemical features of gabbros fine-grained mafic rocks (mafic microgranular enclaves; MMEs) in the Inagawa Granite Ryoke Plutonic Complex were investigated to assess interactions between coexisting silicic magmas, petrogenetic relationships MMEs surrounding gabbros. The exhibit mingling textures that imply coexistence magmas did not undergo complete mixing, but compositions require substantial hybridization homogenization. gabbroic disequilibrium mineral compositions, such as quartz–hornblende ocellar patchy plagioclase crystals with bimodal anorthite contents. These record an abrupt decrease crystallization temperature mechanical mixing crystallizing mush (granitic) melt. Geochemical variations can be explained by fractional (HFC) processes granitic Extrapolation trend a basaltic composition suggests primitive end-member was low-K magma. Given HFC yields magnesian andesite addition small amount melt end-member, compositional modification magma might essential process formation andesitic arc crust.