Geochronology of Magmatic Intrusions and Mineralization of Chagele Copper-Lead-Zinc Deposit in Tibet and Its Implications

Tibet chagele Copper-lead-zinc deposit is in the west end of those copper-polymetallic deposits found in Nyainqentanglha copper-lead-zinc-silver metallogenic belt,and there are two types of mineralization in the mining area,namely,copper-lead-zinc mineralization of the contact metasomatic filling and copper-molybdenum mineralization of porphyry.The zircon LA-ICP-MS U-Pb age and molybdenite Re-Os age show that two types of mineralization almost formed at the same time.The petrogenic age of the northern granite-porphyry related to copper-lead-zinc-silver mineralization is 62.1±1.1 Ma(MSWD=2.7),the southern granite-porphyry which is related to copper-molybdenum mineralization is 63.28±0.86 Ma(MSWD=3.2),and the molybdenite Re-Os age of the south is 61.49±0.60 Ma(MSWD=1.5),which formed at syn-collision stage after northward subduction of the Yarlung Zangbo oceanic basin.This study improves and enriches the time evolvement sequence and genesis of the collision metallogenic stage in Nyainqentanglha copper-lead-zinc-silver mineralization belt,and it also extends westwards its length by 200 km(Qingdu in Xietongmen-Chagele in Angren).As a result,it is found to be a huge copper-lead-zinc-silver metallogenic belt,extending in the direction of east-west more than 800 km,with deposits mainly formed in collection stage.In addition,this study provides important basis to the prospecting of the same deposits in the west of the belt.