Isotope chronological evidence for Upper Jurassic petrogenesis and mineralization of altered granite-type tungsten deposits in the Zhangtiantang area, southern Jiangxi

Abstract：Located in the Zhangtiantang area, southern Jiangxi, the recently discovered Yaolanzai deposit is a typical altered granite-type tungsten deposit. Through highly precise dating of the ages of petrogenesis and mineralization of the tungsten deposit, the authors obtained a SHRIMP U-Pb zircon age of 156.9±1.7 Ma (n=11, MSWD=3.3) for porphyritic fine-grained muscovite granite and Re-Os model ages of 155.2±2.3 to 156.5±2.1 Ma and an isochron age of 155.8±2.8 Ma (n=4, MSWD=0.49) for disseminated molybdenite in ores. According to the above-mentioned ages, combined with the highly precise age data obtained at a regional scale recently, the authors conclude that the tungsten deposits in this area formed in the Upper Jurassic, with their isotopic ages clustering at 150-160 Ma. There is no significant time gap(1-5 Ma) between tungsten mineralization and petrogenesis of its closely related granitoids. The W-Sn mineralization in the area corresponds to the regional-scale Mesozoic second large-scale mineralization in South China.