The Rhenium-osmium Dating And Diagenesis Of Ore-forming Granites From Chagandeersi Molybdenum Deposit, In Inner Mongolia

The Chagandeersi molybdenum deposit is a newly discovered large scale deposit which is located in central-west Inner Mongolia, China. Granite is extremely development in this deposit.The granite mainly include the red meat syenogranite and in fine monzogranite. The mineralization are mainly composed of fine vein disseminated and crumb. The Molybdenum has primarily characteristics of disseminated, lumpy, thin veins distributed in granite rock, It has the characteristics of porphyry type deposits. This paper systematically studied the rocks molybdenite and trace chemical characteristics and the characteristics of rare earth elements, and It analyzes the causes of ore and tectonic environment and other aspects of characteristics. The analysis shows that the adamellite and moyite come from the same source area, the same tectonic setting and the same formation and evolution.The source rocks by early continental margin are subduction and crustal contamination of renovation after partial melting of the form. By molybdenite Re- Os isotopic dating, wo can find out that the molybdenite mineralization time waas about 243 Ma from now, which lasted about 10 Ma. According to the relevant information, the ore mineralization age of molybdenite is very close to Early Triassic age diagenesis of the World syenogranite, which is formed in the early Triassic. Most molybdenum ore are controlled by quartz veins, therefore the molybdenum ore is closely related to the N-W quartz veins.In summary, the mineral source of the Chagandeersi molybdenum are mainly from the Early Triassic period after the collision by a mantle magma and crust remelting magma crystallization differentiation through form. Due to the active tectonic movement of the mine, and better fissures within the mining area, this molybdenum deposit was gradually formed with the post-magmatic hydrothermal ore-forming elements enriched mineralization by mantle with crust migration, and filled in the quartz veins.