~(40)Ar-~(39)Ar Dating, Sulfur and Lead Isotope Geochemistry of the Naduosongduo Ore Section of Maxionglang Pb-Zn Ore Deposit, Tibet

Ore-metal assemblage of the Naduosongduo mining area of the Maxionglang ore deposit is mainly Pb and Zn, and also strong enrichment of W and Sn. Actually, the Naduosongduo mining area is one of the few regions which have potential for the W and Sn ore deposit prospecting in the Gangdese metallogenic belt. The 40Ar-39 Ar analyses of biotite separated from the altered wall rock yield the plateau age and isochron age of 69.57±0.72 Ma and 69.3±1.6 Ma, respectively. The plateau age is consistent with the isochron age within error, which demonstrates that the mineralization of the ore deposit occurred in the Late Cretaceous. The δ34S values of ore sulfides varied from -1.6‰ to 1.9‰, which show that the sulfur mainly came from magmatic rocks related to the mineralization. Ore lead isotopic composition indicates that the ore metals were mainly sourced from the Nyainqentanglha crystalline basement. The preliminary study on the metallogenic epoch and sources of ore-forming materials of the Naduosongduo ore section is of great significance for regional prospecting of ore deposits, which have similar mineralization characteristics with the Naduosongduo.