Abstract:

The Yanqian tungsten deposit is located in east section of Nanling region, the conjunction of the E-W striking Nanling tectonic belt and the NNE Circum Pacific Ocean tectonic belt. The primary mineralization types include skarn type scheelite deposit and wolframitequartz vein deposit. The orebodies occur in the inner and the outer contact zone of the Early Yanshanian granite. Based on the studies of regional geology and deposit geology, the LA-ICP-MS zircon U-Pb and molybdenite Re-Os isochron dating have been carried out to accurately determine the ages of the granite pluton and the mineralized quartz vein within the pluton. The zircon U-Pb age of mineralized pluton is (160.6±0.72) Ma. The Re-Os isotopic age of molybdenite within mineralized quartz vein is (159.2±2.3) Ma. The isotopic dating results show that petrogenic age of the granite is similar with that of the mineralized quartz vein, which means that the magmatism and mineralization occurred in the same period. According to the previous research data, it was considered that the magmatism and mineralization during 160~150 Ma in the Nanling region primarily developed within the mideast section, and might be caused by the large-scale lithosphere extension. The Yanqian tungsten deposit belongs to the same sub-metallogenic series as some famous deposits in the eastern Nanling region, such as Pangushan,Huameiao and Shizhuyuan, with great exploration potential in the depth. The exploration targets in Yanqian area should primarily be aimed at skarn type and quartz vein type tungsten-polymetallic deposits in the inner contact.

Key words: Nanling region, skarn type scheelite deposit, Yanshanian period, zircon U-Pb dating, molybdenite Re-Os dating, isotope