LA-ICP-MS U-Pb dating of zircons from sulfide-bearing quartz veins in the Pingshui copper deposit, Zhejiang Province, and its geological implications

Abstract：The Pingshui copper deposit in Zhejiang Province is a typical volcanics-hosted massive sulfide deposit (VHMSD) in the northeast part of Qinzhou-Hangzhou collision belt between Yangtze and Cathaysia blocks. Its copper mineralization occurred mainly in the quartz-pyrite-chalcopyrite-sphalerite stage. This paper reports LA-ICP-MS U-Pb ages of zircon from sulfide-bearing quartz veins beneath the massive ore body. The results of dating are (981～988) Ma, (950±15) Ma, (926±13) Ma, (899±21) Ma and (93~120) Ma. CL images and Th/U ratios of the zircons show that both Neoproterozoic and Cretaceous zircons are almost of magmatic origin. Geological evidence and the findings indicate that the ore deposit was formed in the Neoproterozoic (~899 Ma) and the ores were affected by Cretaceous (93~120 Ma) thermal event. These results are of great significance for further researches on the genesis, formation and evolution of the Pingshui copper deposit and also provide chronological information in search for contemporaneous VHMSD along the Qinzhou-Hangzhou collision belt between Yangtze and Cathaysia blocks.