Tectonic Evolution And Ore-controlling Function Of Daping Gold Deposit In The Ailaoshan Belt

The Ailaoshan gold deposit in southwestern China is an important part of the Sanjiang metallogenic province in China.The Daping gold deposit is located in the southeast of the region and has the basic characteristics of a typical orogenic gold deposit.The Daping Gold Mine is strictly controlled by faults,and the ore-controlling faults and metallogenesis have multi-stage characteristics.The previous research was limited to the judgment of the three main faults in the mining area and the classification of the types of wall rock alteration.It did not analyze and summarize the nature of the ore-controlling faults and the phase of wall rock alteration at each ore-forming stage of the main mining section.The alteration-mineralization network structure and its oreforming coupling relationship are also unclear.This study starts with the characteristics of the veins,the nature of fractures and the occurrence of scratches,analyzes the structure of the Daping gold deposit,summarizes the kinematic characteristics,clarifies the relationship between the tectonic stage,metallogenic stage and alteration stage,and comprehensively analyzes the structure of the mining area Ore control.The Daping gold deposit is divided into four metallogenic stages: ? quartz-iron dolomite-scheelite stage;? quartz-pyrite-chalcopyrite stage;? quartz-polymetallic sulfide stage;? quartz-calcite stage.The wall rock alteration of the Baishapo and Maomashu mines can be divided into four stages: iron dolomite stage,sericite stage,chlorite-apallite stage and carbonate stage;and Bajiaoling mine The main types of alteration in the segment are sulfidation and carbonation,and there is no obvious alteration phase division.The structural deformation of the mining area can be divided into three deformation stages,namely: D1 stage,D2 stage and D3 stage.In the Baishapo-Maumushu ore section,the D1 stage fault is a sinstral slip fault,the D2 stage fault is a dextral reverse fault,the D3 stage ore break fault is a dextral slip fault,and the vein face fault is a sinstral normal fault.Compared with the former,the D1 stage fault property of the Bajiaoling ore segment is a reverse fault,the D2 stage fault property is a dextral slip fault,the D3 ore-breaking fault property is a sinistral reverse fault,and the vein face fault property is a sinistral slip fault.In the Baishapo-Maumushu ore section,the D1 stage deformation controls metallogenic stage ?,and the corresponding alteration stage is the iron dolomite stage;the D2 stage deformation controls metallogenesis stages ?,?,and ?,and the corresponding alteration stages are sericin,respectively.The petrification stage,the chlorite-epidermitization stage and the carbonate stage.Similar to the former,the metallogenic stage I,metallogenic stages ?,?,and ? of the Bajiaoling ore segment are closely related to the D1 and D2 deformation stages of the Bajiaoling mine.Combining the fault occurrence Mohr circle,field geological characteristics and EBSD,the Daping gold deposit experienced a northwest-to-medium-low temperature right-line tectonic movement during the ore-forming period,and the direction of the maximum principal stress ?1 was SN.Tectonic movement on the left,the direction of maximum principal stress is NNE.