Genetic Analysis Of Cuoga Lead-zinc Deposit In Mozhugongka County, Tibet

The Cuoga lead-zinc deposit is located in the middle-south section of the Gangdise-Nyainqin Tanggula plate,which is located at the junction of the Gangdese continental margin volcano-magma arc and the Nianqing Tanggula arc back fault.As a lead-zinc deposit with certain mineralization potential in the Gangdise metallogenic belt,the Gano-lead-lead-zinc deposit has a low level of comprehensive research,and its detailed mineralization study can not only determine the genetic type of the deposit,but also help to improve And rich regional metallogenic theory is of great significance.In this paper,using mineralogical,petrological,mineralogical and geochemical research methods,combined with previous data,the regional geological background of the Cuoga lead-zinc deposit,the geological background of the mining area,the geological characteristics of the deposit,the geochemical characteristics of the deposit and the diagenesis of the deposit The mechanism of mine action has carried out a more comprehensive analysis and discussion..The Cuoga lead-zinc ore body is mainly distributed in the second volcanic rocks of the Xionglai Formation of the Late Triassic.It is controlled by the fault structure of the mining area and is layered and layered.There are four lead-zinc ore bodies in the mining area,Pb-17,Pb-14,Pb-15 and Pb-15-1.The ore minerals are mainly galena,sphalerite,and pyrite.The gangue minerals are mainly quartz and carbonate minerals.The massive,breccia and strip-like structures are the main ore structures in the mining area.The ore structure is mainly composed of its granular structure,and also has a structure of crushed structure and internal cleavage.The surrounding rocks of the ore body are mainly andesite,tuff,breccia and marble.The surrounding rock alterations include silicification,carbonation,sericitization,chlorite,and green curtain petrochemical.The ore-forming period is divided into hydrothermal and surface generation ore stages,early quartz/pyrite stage,medium-term pyrite/galena/xetite stage and late quartz/carbonate stage.The analysis of the main trace elements of the volcanic rocks of the Xionglai Formation in the Kouyu mining area shows that the light rare earths are relatively enriched and the heavy rare earth elements are relatively depleted;the Eu negative anomaly;the Ce has no obvious anomaly;the high field strength element has a significant loss,while the large ion lithophile The elements are relatively enriched and generally exhibit similar characteristics to typical arc volcanoes.Combined with the zircon U-Pb age of volcanic rocks,the magmatic action of the Xionglai Formation rocks in the Late Triassic-Early Jurassic formation of the Lhasa terrane was determined.In the early initial island arc stage,the basalt spurt is the main function;as the shell source material composition increases in the magma source area or magma,the late intermediate and acid volcanic eruption is characterized by the continental margin arc.The characteristics of the S and Pb isotopes indicate that the sulfur is mainly derived from deep source sulfur or magma;lead is mainly derived from the shell source.H and O isotope studies indicate that ore-forming fluids are mainly from circulating underground hot water with atmospheric precipitation as the main body,but at the same time retain some of the components of magmatic water.In addition,the Si isotope study in the mining area found that the overall negative value of?³⁰Si is very close to that of typical Geyserite.A large number of cryptoexplosive breccia,breccia ore and blade-like calcite are developed in the mining area,indicating that there may be fluid boiling in the Cuoga mining area.This paper analyzes the diagenesis and mineralization of the Cuoga lead-zinc deposit by conducting a large number of analytical test data systems in the Cuigong lead-zinc mining area.It is preliminarily believed that the genetic type of the Cuoga-lead-zinc deposit is a medium-low temperature hydrothermal vein type lead-zinc deposit.