Magba granitoids are made up of granites, orthogneiss, migmatites, metagabbro, mafic dykes and mylonites with respectively porphyritic, porphyroblastic, grano-lepido-porphyroblastic, and cataclastic texture. Mafic dyk...Magba granitoids are made up of granites, orthogneiss, migmatites, metagabbro, mafic dykes and mylonites with respectively porphyritic, porphyroblastic, grano-lepido-porphyroblastic, and cataclastic texture. Mafic dykes and metagabbro occur as intrusives into the mylonitic and granitic rocks. Magba rocks were subjected to whole rock geochemistry analyses and results show that those rocks have the chemical composition of gabbro, monzodiorite, monzonite syenite, quartz-monzonite, granodiorite and diorite. The rocks are metaluminous, display high-K, calc-alkaline to shoshonitic affinities and plot on the field of volcanic arc granites and are formed by differentiation of I-type magma. They are largely situated within the syn-collision to within plate fields, show a subduction—to collision-related magmatism, and suggest their emplacement during the syn—to post-collisional phase of the Pan-African orogeny.展开更多
文摘Magba granitoids are made up of granites, orthogneiss, migmatites, metagabbro, mafic dykes and mylonites with respectively porphyritic, porphyroblastic, grano-lepido-porphyroblastic, and cataclastic texture. Mafic dykes and metagabbro occur as intrusives into the mylonitic and granitic rocks. Magba rocks were subjected to whole rock geochemistry analyses and results show that those rocks have the chemical composition of gabbro, monzodiorite, monzonite syenite, quartz-monzonite, granodiorite and diorite. The rocks are metaluminous, display high-K, calc-alkaline to shoshonitic affinities and plot on the field of volcanic arc granites and are formed by differentiation of I-type magma. They are largely situated within the syn-collision to within plate fields, show a subduction—to collision-related magmatism, and suggest their emplacement during the syn—to post-collisional phase of the Pan-African orogeny.
