Zircon U-Pb Dating and Petrogenesis of the Langmusi Volcanic Rock in West Qinling Orogenic Belt
An integrated study of petrology,zircon U-Pb dating and geochemistry for the Langmusi volcanic rock in the middle part of the west Qinling were carried out.The Langmusi volcanic rocks consist of andecite and trachyandecite.Results show that the zir-con LA-ICP-MS U-Pb age of the Langmusi volcanic rocks is 217±4 Ma.The Langmusi volcanic rocks are characterized by enrich-ments of LILE(e.g.Rb,Ba,U,Th,Pb)and HFSE(e.g.Ta,Nb)depletion,with ΣREE=195.9～418 ppm,(La/Yb)N= 12.16～13.93,δEu= 0.72～0.81,which show the magma of the volcanic rocks was dominantly derived from crustal materials.The Langmusi volcanic rocks were generated by partial melting of lower crust,granodiorite and volcanic rock resulted from lithospheric delamination in post-collisional setting.
万方数据
维普
