Zircon SIMS U-Pb Geochronology of Host Granitoids in Wushan and Yongping Copper Deposits, Jiangxi Province
DING Xin, JIANG Shao-yong, NI Pei, GU Lian-xing, JIANG Yao-hui(State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China)
Wushan and Yongping deposits are two of the most important copper deposits in the Lower Yangtz Mineralization Belt. In this study, SIMS U-Pb dating was performed on zircons from host granitoids in both Wushan and Yongping deposits, Jiangxi province. Zircons from both Wushan and Yongping deposits yield two distinct age groups. In Wushan deposit the zircon ages are 145±4 Ma and 121±3 Ma. In Yongping deposit the zircon ages are 160±2 Ma and 135±7 Ma. The zircons of earlier stage were likely formed during emplacement of intrusion, and the later ones formed during the later magmatic evolution and/or hydrothermal alteration. We suggest that the granitic magma intrusion ages of Wushan and Yongping deposits are 145±4 Ma and 160±2 Ma, respectively. These ages also represent the ore forming age for both skarn and porphyry ores that related to the intrusions of Yanshanian magmatism in these two deposits.