The Mineralization Characteristics Of Pb-Zn Deposit In Narusongduo And The Comparison With The Genesis Of Sinongduo Deposit In Tibet

Gandise metallogenic with copper, gold, lead, zinc and other mineral resources has great potential,which is a world- class copper iron polymetallic metallogenic belt in the west of China. Copper(molybdenum, gold) mineralization, lead,zinc,silver mineralization are the main mineralization of Gangdese metallogenic belt on the southern and northern edge. Currently, The southern margin of Gangdise found 350 km, width 40 kilometers of the porphyry copper belt, and porphyry copper mineralization, Having carried on the thorough research to them. However,the northern margin of the lead,zinc,silver mineralization and porphyry was only known in a short time. Its representative is Narudongduo Pb-Zn deposit,which formed in the longgeer gongbujiangda fault uplift zone of central Lhasa block of Gangdisi metallogenic belt, it mainly has the number I of hidden explosive angle conglomerate type, number III of the lead zinc mineralization in the main mineralization model. This paper is mainly through the study of the mineralization characteristics of Narusongduo deposit,as well as the comparative study of the deposit genesis, metallogenic period, geochemical characteristics and ore controlling factors of Sinongduo deposit,which is more than ten kilometers in the West from Narusongduo. Understanding this paper is as follows:1. Before the stage of collision between India plate and Eurasia plate, the process of subduction of the Neo Tethys ocean, high temperature causes the molten mantle material emission. At the same time, high temperature caused the melting of crustal material again. At the end of the dive, Sinongduo lead zinc deposit was formed. During the early stage of the orogenic stage, Narusongduo deposit was formed in No. III and No. I. In Narusongduo deposit, and the magmatic rocks related to mineralization are mainly quartz syenite porphyry. In Sinongduo deposit, the metallogenic magmatic rock is granite porphyry,which is similar to the mineral source of Narusongduo deposit.2. Pb-Zn mineralization of Narusongduo is mainly related to strata, intrusive rocks and related tectonic activities. It is clear that the cryptoexplosive breccia type mineralization is mainly from strata of paleocene dianzhong formation tuff of the periphery of the porphyry.In No.III mining area, the skarn lead-zinc and Permian Xiala formation of marble and quartz syenite porphyry have a great relevance. Some stratification mineralization is visible at the border of the porphyry outside of the Dianzhong formation tuff and Angjie formation sand slate. Fissure in the tuff and shale was fill with fine vein type ore body widely. At the same time,the unconformity surfaces distribute altered rock type ore bodies and so on. According to comparative study of the ore deposits with Sinongduo,this paper mainly study in the metallogenic characteristics, geochemical characteristics, mineralization period, structural characteristics, source area, metallogenic model and so on.3. According to the comparative study of geochemical characteristics, Chemical characteristics of REE between Narusongduo and Sinongduo deposits,we found the geochemical characteristics of the two mining areas are obvious,rock types and distribution of REE showed similar but slightly changing characteristics. The coarse and fine porphyry of Narusongduo Pb-Zn deposit show obvious Calcium alkaline,but Sinongduo don't,Sinongduo has the tend to tholeiite series. Two REE elements in the mining area show LREE enrichment, Medium rare earth loss, HREE slightly enriched with obvious negative Eu anomaly right distribution pattern.4. In the mining area of the west section of No. III of Narusongduo, Middle Permian Xiala formation Limestone is the main Pb-Zn deposit type,which is carbonate formation,and the main ore prospecting model for No. III deposit. The research degree is not deep enough. There are some debates about the metallogenic is the first or the tectonic movement.I do not exclude the structure and mineralization are simultaneously carried out, and are dominated by a certain characteristic. The work process No. III deposit has not yet been to the exploration stage.but the No.I did. According to a large number of field geological work, This paper includes subjects of structural geology, mineralogy, petrology, mineralogy, geochemistry, isotopic dating and metallogenic prediction. According to the analysis of the genesis and ore controlling factors of Narusongduo and Sinongduo Pb-Zn deposits. Summing up the difference between mineralization and metallogenic model,and providing a theoretical basis for enriching metallogenic characteristics of Pb-Zn mining area in the middle of gangdise.