LA-ICP-MS Zircon U-Pb Dating of Granodioritic Porphyry located Zhuxi Copper-Tungsten Mine in Northeast Jiangxi and Its Geological Significance

The Zhuxi ultra-large type copper-tungsten deposit in the Northeast Jiangxi province located in Taqian -Fuchun metallogenic belt which belongs to Jiangnan ancient island-arc, the discovery of the deposit has verified Southern Tungsten North Expansion perspective and challenge the viewpoint that Tungsten located in the south but the copper located in the north of Jiangxi provience, but the previous lack of accurate chronology study related to Zhuxi copper-tungsten mineralization of granite not enough, resulting in the geodynamic background of understanding. In this study, on the basis of detailed field investigation, core logging and petrology studies on the granodioritic porphyries which had intruded into the Middle Proterozoic Shuangqiaoshan group and with copper mineralization alteration, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating, we obtained the granodioritic porphyries zircon 206Pb/238U weighted mean age of 847.2±9.4Ma (MSWD=0.111), which can represent the granodiorite porphyry magma emplacement and crystallization age, belonging to the neoproterozoic. The results reveal that the granodioritic porphyries of Zhuxi copper-tungsten mine is a product of the early Neoproterozoic Southern China ancient oceanic crust subduction and Yangtze and Cathaysian continental blocks collisional magmatism, the magmatic activity provides the basis for the metallogenic Qinzhou-Hangzhou metallogenic belt, and the magma event is close related to the Taqian-Fuchun ore belt mineralization, it also provides new evidence for the study of Zhuxi ultra-large type copper-tungsten deposit.