Geological Characteristics And Metallogenetie Model Of "The Great Wall' Gold Deposit Eastern Heibei

Guided by the metallogenic system theory,the dynamic metallogenic theory as the instruction,in summing up the LengKou fault Xiaojinggou,Nangou,Juntun The Great Wall Gold Deposit,geological characteristics of the basis,through the study of Xiaoyingzi Composite Pluton,geochemical characteristics of the deposit,C-H-O-S isotope,fluid inclusions analysis,to investigate the source of ore-forming materials,the fluid source of ore deposits,combined with the tectonic evolution and gold mineralization,regional,temporal and spatial distribution,to identify the type and ore-forming processes of mineralization,set up the metallogenetie model of The Great Wall Gold Deposit.The progresses of study are mainly as follows:1.Through the Xiaoyingzi Composite Pluton Granodiorite and K-feldspar Granite sample analysis indicate that the Granodiorite belongs to the crust mantle mixed source I type granites,formed in the bottom of the strongly thickened crust,source area mainly residual Garnet+Pyroxene+Homblende.The K-feldspar Granite belongs to A type granites,the magma originated from the bottom of the thickened crust,the source area of residual phase may be composed of Plagioclase+Pyroxene+Hornblende+Garnet.2.Trace elements analysis indicates,Xiaoyingzi Composite Pluton belongs to the same collision orogenic and post collisional orogenic granite,show that the source rocks were formed in the syn collision stage after the thickened lithosphere extensional collapse of the transition phase to intraplate anorogenic.I type Granodiorite formed in compressional environment,A type K-feldspar Granite formed in relatively extensional tectonic setting.3.REE,C-H-O,S isotopes indicate that the relationship“The Great Wall"Gold Deposit mineralization and magmatism closely,the characteristics of the mineral has multiple sources,mainly from the basement metamorphic rocks and deep crust.Ore-forming fluid may be a mixture of water and atmospheric precipitation metamorphic magmatic water,sealed basement metamorphic layers.REE,C-H-O,S isotope study results also showed that the mineralization is similar to mine,but has its own unique metallogenic evolution.4.The Great Wall Gold Deposit strong silicified zone of primary fluid inclusions in the measurement results show that the homogenization temperature of fluid inclusions in140³80?,were focused on 200²80?,check the fluid density is 0.687⁰.984g/cm³,changes in the larger.Calculation of the ore forming pressure is in the range of 381⁹97MPa,metallogenic depth is in the range of 1.27³.32km.Fluid inclusion analysis shows that,the deposit formed in the condition of microtherm or mesotherm and shallow environment.5.The composition of fluid inclusions analysis indicate that the ore-forming fluid connected with the magmatic hydrothermal fluids,but also,connected with the underground thermal brine.Xiaojinggou fluid inclusions high Ca²⁺,Mg²⁺,its mineralization closer relationship with the surrounding rock,and Shuiquannangou,Touzhaimengou,Juntun fluid inclusions indicate ore-forming fluids closely related to magmatic hydrothermal.6.Xiaoyingzi composite pluton belong to crust-mantle mixed source,the emplacement for gold deposit mineralization brings the heat,partially into minerals and ore-forming fluids.With the rock emplacement,the volatile components in upper body gradually increased,the pressure increases,the formation of high-pressure fluid,with high-pressure fluid pressure increases,hidden explosion occurred in a shallow shattered role,Meanwhile fluid into the mineral can be uninstalled mineralization in the appropriate environment,forming a hidden explosive breccia body shattered.After breccia formation process and the formation of magmatic hydrothermal precipitation and from surface,sealed in metamorphic basement rocks in the water to produce heat-driven circulation in the rock,Extraction basement metamorphic rock,the gold cap as minerals,ore-forming hydrothermal fluids converge in breccia rock inside and near a tectonic fissure account by filling the role of trying to"unload",to form a mineral enriched The Great Wall Gold Deposit.