The Re-Os Isotopic Dating of Molybdenite from the Dasuji Molybdenum Deposit in Zhuozi County of Inner Mongolia and Its Geological Significance

The Dasuji molybdenum deposit in Zhuozi County of Inner Mongolia is a porphyry molybdenum deposit discovered in the northern margin of North China Block in recent years. Through the ReOs dating of molybdenite from quartz porphyry, the isochron age of (222.5±3.2) Ma and the model age of (222.1±3.2) Ma～(224.6±3.4) Ma were obtained, which means molybdenite formed in late Triassic. It also means that the magmatism and mineralization took place in Indosinian in the northern margin of North China Block. This is significant to prospect the Indosinian molybdenum-polymetallic deposits in this area.