Permo-Triassic magmatism and metallogeny of Northern Vietnam in relation to the Emeishan plume

摘要

We have shown that the occurrences of Permo-Triassic magmatism in northern Vietnam compose the southwestern and southeastern flanks of the Emeishan large igneous province, shifted along the large-amplitude Ailao Shan-Red River shear zone. Based on new geochronological (U-Pb and Ar/Ar) data, two stages of magmatism related to the Emeishan plume have been recognized. At the first, Permian, stage (260 Ma), abundant picritoids of the Song Da and Song Hien zones formed, and at the second, gabbro-syenite and gabbro-monzodiorite associations of the Lo Gam zone, layered peridotite-gabbro massifs of the Nui Chua complex, high-alumina granites of the Phia Bioc complex, and basalt-rhyolite association of the Song Hien zone were produced. The metallogenic specialization of the Permo-Triassic magmatism of northern Vietnam is considered.