Metallogenic Characteristics,Deposit Genesis,Metallogenic Mode And Regularity Of The Gold Polymetallic Deposit In Qingchengzi Deposit-Concentrated Area,Liaoning

Liaodong is one of the important non-ferrous and precious metal metallogenic areas in Northeast China,located in the northern margin of the North China Craton,On the basis of summarizing the regional ore-forming geological background and the tectonic construction of the ore concentration area,this paper selects the typical deposits in the Liaodong area?Baiyun,Xiaotongjiapuzi,Yangshu,Linjiasandaogou gold mine,Gaojiapuzi silver mine,Xiquegou,Benshan,Zhenzigou,Diannan lead-zinc mine?,This paper systematically studies the geology of mining area,ore deposit,fluid inclusion,isotopic geochemistry characteristics of ore deposit and magmatic action related to mineralization.The genetic classification of the deposits is carried out,the metallogenic geology and process are further determined,the metallogenic model is established,the metallogenic regularity is inverted,and the metallogenic prediction is carried out.The following new understandings are obtained in this paper:1.Starting from the ore deposits and deposit geological characteristics,fluid inclusions,isotope geochemistry,and mineralization dynamics background of the typical deposits in the ore concentration area,the gold polymetallic deposits in the study area are divided into magmatic hydrothermal type,such as Baiyun gold mine;and Intrusive rocks related hydrothermal type,such as Xiaotongjiapuzi gold mine,Gaojiapuzi silver mine,Yangshu gold mine and Qingchengzi lead-zinc mine.According to the different spatial distribution of mineral deposits and ore-forming geological bodies,the gold polymetallic deposits in the Qingchengzi ore concentration area are classified into near-hydrothermal types?such as Qingchengzi lead-zinc?and mid-far hydrothermal types?Such as Xiaotongjiapuzi gold mine,Gaojiapuzi silver mine,Yangshu gold mine and and Baiyun gold mine?.2.The Baiyun gold mine is produced in the rock formation of the?sillimanite?biotite schist,the biotite granulite and the marble lentils of the Gaixian Formation.The Baiyun nappe structural belt is the main ore-controlling structure of the Baiyun gold mine;The Xiaotongjiapuzi gold mine,Gaojiapuzi silver mine and Yangshu gold mine are produced in the?garnet?mica schist,the biotite granulite and the dolomite marble interbedded zone of the third member of the Dashiqiao Formation,both of which are controlled by jianshanzi sub-first-order interbedded fault or slicing fault;Lead-zinc mines?Xiquegou,Benshan,Zhenzigou and Diannan?are produced from?calcium-magnesium silicate strip-zone?dolomite marble and?garnet mica,sillimanite?schist,mica granulite interbed zone.The fold structure provides favorable space for mineralization.3.Both the Xinling and Shuangdinggou rocks are Mesozoic Late Triassic intrusions,providing a heat source and some metallogenic materials for the metallogenic metallogenesis in the area.The ore-forming geotectonic setting may be related to the plate fragmentation associated with the continental crust reentry of the North China-Yangzi deep subduction.The dadingzi and shijialing rock masses are paleoproterozoic intrusions.Regional faults caused by rock mass emplacement and a series of faults?including inter-layer faults?induced by rock mass intrusion control the ore concentration area.The spatial distribution of veins and veins.4.Magnetotelluric sounding?AMT?and 1:50,000 bouguer gravity show that the Qingchengzi polymetallic ore concentration area appears as a relatively gentle gradient zone on the Bouguer gravity anomaly contour map,and the deep low-density rock masses in this area invade into the lower part of the Liaohe Group,or the deep-developed Mesozoic concealed,semi-hidden granite bodies.5.The rich liquid inclusions are developed in the Baiyun gold deposit,and the H₂O-CO₂three-phase inclusions are locally developed,and a small amount of gas inclusions are developed.The ore-forming temperature in the main metallogenic stage is 240-310°C.The ore-forming fluid is a H₂O-CO₂-CH₄-NaCl system containing N₂,a medium-temperature,low-salt,low-density water-salt fluid.Combined with H and O isotopic characteristics,its ore-forming fluid is a magmatic fluid;The Gaojiapuzi silver deposit,the Xiaotongjiapuzi gold deposit,the Yangshu gold deposit,and the Linjiasandaogou gold deposit develop rich liquid inclusions,localized gas phase inclusions,and develop a small amount of H₂O-CO₂ three-phase inclusions and CO₂ two-phase inclusions.The main metallogenic temperature is between 120and 210°C.The ore-forming fluid is an H₂O-NaCl-CH₄-CO₂ system containing H₂,medium temperature low salinity low density water salt fluid.It is a reducing fluid with deep source characteristics.Combined with H and O isotopic characteristics,the ore-forming fluid is defined as magmatic water and atmospheric precipitation;The lead-zinc deposit develops a rich liquid inclusion and locally develops a three-phase inclusion of H₂O-CO₂.The ore-forming temperature range is large,and the ore-forming temperature is mainly between 190 and 310°C.The ore-forming fluid is an H₂O-NaCl-CH₄-CO₂ system containing H₂,medium temperature and low salinity water salt fluid.It is a reducing fluid with deep source characteristics.Combined with H and O isotopic characteristics,the ore-forming fluid is defined as magmatic water and atmospheric precipitation.6.The S isotope characteristics of the Baiyun gold deposit reveal that its ore-forming material is derived from magmatic hydrothermal fluid;The C and O isotopes of the Gaojiapuzi silver deposit,Xiaotongjiapuzi gold deposit,Yangshu gold deposit,Linjiasandaogou gold deposit and Qingchengzi lead-zinc deposit indicate that the organic matter in the strata may be involved in the gold-rich ore deposit.The S and Pb isotopes reveal that their ore-forming materials are derived from the mixing of seawater sulfate reduction and deep magmatic hydrothermal sources;The strontium isotope data indicate that the ore-forming materials of the gold-silver-lead-zinc deposits in this area are mainly derived from the lithosphere with a high⁸⁷Sr/⁸⁶Sr ratio brought by the fluid.7.The Qingchengzi ore concentration area has experienced areas of early intense extension,rifting and sedimentation and late stage of crushing and fold-forming orogeny.The development of clastic rocks and carbonate rocks during the rifting period has enriched the gold and laid the foundation for mineralization.In the Mesozoic,large-scale tectono-magmatic activities resulted in partial melting of the lower crust and the formation of intermediate-acid magma rich in gold and other metallogenic elements.During the upwarping process,intermediate-acid magma activated and quenched Au,Ag,Pb and Zn metallogenic elements in the strata of Liaohe Group.Highly mineralized ore-forming fluids migrated along the ore-controlling structure and metallogenic structural plane,near the contact zone between rock mass and carbonate rock,a near-hydrothermal lead-zinc deposit was formed,and then outward?a little farther from the rock mass?a mid-far hydrothermal silver-gold deposit?Gaojiapuzi silver mine,the Xiaotongjiapuzi gold mine,the Yangshu gold mine,etc.?,there may be hidden rocks at the bottom of the Baiyun gold mine,and the Baiyun gold mine of mid-far hydrothermal were formed vertically.8.Based on the summary of metallogenic regularity and metallogenic model,the metallogenic prediction of the study area was carried out.Shallow prediction area:The east and west extension of the Baiyu-Baiyusandaogou gold belt has potential for gold prospecting;Near Linjiasandaogou area,thin-layered silicified and sericitized biotite granulites are developed,and veins are developed,which has great potential for gold?silver?prospecting.Kuangdonggou area,located in Erdaogou metallogenic fracture,has pyritization and galena mineralization in fault breccia,and is a better lead-zinc metallogenic area near Xinling rock mass.Deep prediction area:There may be concealed rock mass in the lower part of Baiyu gold mining area,which has certain potential in the deep part;Xiaotongjiapuzi-Gaojiapuzi Au-Ag deposit,which is close to the rock mass,has enough magmatic hydrothermal action,and has prospecting potential in the deep part.