Geological Geochemistry Characteristics And Causes Of Formation Of The Huanaote Ag-Pb-Zn In Deposit, Inner Mongolia, China

The Huanaote deposit is located in Inner Mongolia which is a medium-low temperature hydrothermal vein type deposit in the Xingmeng orogenic belt in the southern margin of the Great Hinggan Range.Based on the analysis of materials and Pb isotope of the Huanaote deposit,the genetic mechanism was discussed.The results showed that ore minerals contain common sulfide,include pyrite,sphalerite,galena,and also some native bismuth,bismuthides,etc,pyrargyrite,dyscrasite is mainly silver-bearing minerals.The isomorphic silver and independent silver minerals are the two main forms of silver occurrence.The in situ sulfur isotope composition of ore minerals shows that the overall?³⁴S values ranges from 2.4‰to 7.9‰,with a mean value of 5.6‰,reflecting that sulfur?mantle sulfur 0±3‰?may originate from the deep source.The distribution of the?³⁴S values showed a double-tower feature in the histogarm,with peaks at 5⁶‰and 7⁸‰,respectively,indicating an open environment.The sulfur isotope indicates the source of sulfur is mainly from a deep magma,which mixed with sulfur from the crust.The ²⁰⁶Pb/²⁰⁴Pb value of the in situ Pb isotope composition of the Huanaote deposit is 18.302¹8.313,the average is 18.302;the ²⁰⁷Pb/²⁰⁴Pb ratio is 15.543¹5.553,the average is 15.547;the ²⁰⁸Pb/²⁰⁴Pb ratio is38.073³8.115,the average is 38.088,indicating that the lead is a normal radioactive.By comparing the in situ lead isotope composition of Huanaote mining area with previous data and host rock,and combining the magmatic activity and tectonic movement of the area,the ore-forming materials are mainly derived from the deep?likely mantle?.The Pb isotope tectonic environment discriminant diagram and the??-??genetic classification chart further explain that the lead source is a deep magma and there is also a small amount of crustal lead.The ore-forming processes are related to the regional large-scale fault resurrection through the stretching motion inside the continental plate.The temperature inside the continent rises,causing the deep magma to rise and invade to carry part of the crustal material,providing hydrothermal fluid for mineralization.In this process,there is a mixture of materials of the magma and the surrounding rock.