Exploration Model And Metallogenic Prediction Of Jisong Lead-zinc Deposit In Southern Tibet

There are a large number of gold,antimony,lead,zinc,silver deposits and tungsten tin beryllium rare metal deposits in the Himalayan metallogenic belt.The Jisong lead zinc deposit is located in the Cuonadong dome cover(Jurassic shallow metamorphic slate)of the eastern part of the northern Himalayan dome belt in the Himalayan metallogenic belt.On the basis of geological mapping,geological section survey,geochemistry and geophysical exploration in Jisong mining area,combined with fluid inclusions,S-Pb isotopes,sulfide trace elements and Ar-Ardating,the material source and genesis of Jisong ore body are studied,and an exploration model is established for ore-forming prediction.The Jisong lead-zinc deposit is a mesothermal hydrothermal vein type deposit.According to the vein cutting relationship and mineral intergrowth combination,it is divided into four stages:(?)galena arsenopyrite pyrite stage,(?)pyrrhotite sphalerite chalcopyrite quartz stage,(?)quartz calcite pyrite stage and(?)quartz stage.The results of fluid inclusions show that the mineralization temperature range is 280 ? ?340 ?,the salinity range is 2?9% Na Cl EQV,the mineralization pressure is 236?261bar,and the mineralization depth is 921?1016 meters.The H-O isotopic study of quartz shows that the water of ore-forming fluid is mainly the formation water,with the addition of magmatic water.The sulfur isotope shows that S is mixed sulfur,S in the early mineralization stage mainly comes from magma,S in the middle mineralization stage mainly comes from magma and strata,S in the later stage mainly comes from strata,and Pb in Jisong lead-zinc mine comes from the light colored granite in lunadong.According to the direction of Zn / Cd ratio in sphalerite,sphalerite is a medium low temperature hydrothermal deposit.The Ar-Ar results of Sericite show that the metallogenic age is 18 Ma,so Jisong Pb Zn deposit is a meso low temperature hydrothermal vein type deposit,and the ore-forming material mainly comes from the light colored granite of lunadong.The results of regional stream sedimentary survey and lithogeochemical section show that the the Cuonadong dome has obvious element zoning from the core to the edge.From the inside to the outside,they are: high temperature W-Sn-Be-Bi element combination,medium temperature Cu Pb Zn Ag element combination,and medium low temperature Au sb as element combination.Jisong Pb Zn deposit is located in the middle temperature Cu Pb Zn Ag zone.From sulfide trace elements,it is found that the main lead-zinc ore in Jisong is Zn,followed by Pb,Cu,Ag,and a small amount of W,Sn and Bi elements.Compared with the deep to shallow element zoning of zhaxikang orebody,it is found that the Zn Pb Cu Sn w zoning of zhaxikang orebody is approximately the same as that of zhaxikang orebody,while compared with Zhaxikang,Jisong has higher metallogenic temperature,pressure and depth.Therefore,it is speculated that Zhaxikang and Jisong are in different metallogenic positions in dome metallogenic system,and Jisong has larger metallogenic depth There may be Jisong type Pb Zn deposit in the deep part of zhaxikang.The results of regional stream sedimentary survey and lithogeochemical section show that Cuonadong dome has obvious element zoning from the core to the edge.From the inside to the outside,they are: high temperature W-Sn-Be-Bi element combination,medium temperature Cu Pb Zn Ag element combination,and medium low temperature Au sb as element combination.Jisong Pb Zn deposit is located in the middle temperature Cu Pb Zn Ag zone.From sulfide trace elements,it is found that the main lead-zinc ore in Jisong is Zn,followed by Pb,Cu,Ag,and a small amount of W,Sn and Bi elements.Compared with the deep to shallow element zoning of zhaxikang orebody,it is found that the Zn Pb Cu Sn w zoning of Zhaxikang orebody is approximately the same as that of zhaxikang orebody,while compared with Zhaxikang,Jisong has higher metallogenic temperature,pressure and depth.Therefore,it is speculated that Zhaxikang and Jisong are in different metallogenic positions in dome metallogenic system,and Jisong has larger metallogenic depth There may be Jisong type Pb Zn deposit in the deep part of Zhaxikang.Although Jisong lead-zinc mine has a high metallogenic temperature and a well-developed structure in the mine area,because the ore body is too close to the dome,the dome extrusion in the uplifting stage leads to the main fault compression in Jisong mine area,which makes the ore storage space smaller and the scale of Jisong lead-zinc mine smaller.