New Dating of the Piaotang Granite and Related Tungsten Mineralizationin Southern Jiangxi

The Piaotang tungsten deposit, a well- known tungsten -tin (Mo, Bi) polymetallic deposit in southern Jiangxi, China, consists of the Piaotang, Muziyuan and Dalongshan ore segments. Little work has been done on the ages of ore-formation and related granite in Piaotang. The intrusion ages of the Piaotang and Muziyuan granites are 161.8±1Ma and 153.3±1. 9Ma, respectively, using the single grain-zircon U-Pb isotopic method. The mineralized age of the Muziyuan ore segment is determined as 151.1±8.5 Ma ( N=6,MSWD=11.8) using the molybdenite Re-Os isotopic method. A metallogenic age of 152±1.9Ma for the Piaotang is obtained using the quick neutron mobilization 40Ar/39Ar age method of mica from the major ore vein. All these age data indicate that the mineralization in this area occurred at the same time as or slightly later than that of granite intrusion. It is found that some representative tungsten deposits in southern Jiangxi such as the Taoxikeng and Dajishan present the similar characteristics in ages of mineralization and diagenesis. Therefore, this kind of mineralization is of great representative in southern Jiangxi. These are two common and representative cases for the granite-related tungsten-rare-metal deposits in southern Jiangxi such as the well-known Dajishan tungsten deposit and Taoxikeng tungsten deposit. Data by this study and the ages reported by previous research show that the tungsten-tin deposits in Southern Jiangxi Provice are the results of large-scale granitic magmatism and the associated rare-metal minarelization in the middle Yanshanian period of the Mesozoic Era.