Metallogenic Regularity And Prospecting Direction Of Baizhangzi Gold Deposit,Western Liaoning

Baizhangzi gold deposit in Liaoning Province is a medium to large scale gold deposit,which has a long history of mining and is located in the eastern Hebei to western Liaoning gold belt.The gold mineralization types in the mining area can be divided into two types:sulfide quartz vein type and altered rock type,whose distribution is obviously controlled by Baizhangzi complex.In this article,through field geological survey,mining tunnel geological mapping,petrography,geochemistry,diagenetic pyrite metallogenic chronology,thermoelectricity,such as study,the gold metallogenic regularity and metallogenic model provides guidance on the prospecting for deep basis,and according to the rule of prospecting prediction,3d visualization mining model verification,get better effect.The Baizhangzi complex is a series of alkaline,quasi-aluminous and potassic basalt rocks formed in the late Triassic,among which the granitic lithology can be subdivided into biotite hornblende monzonite,biotite quartz monzonite and monzonite.The formation ages range from old to new,respectively,biotite hornblende monzonite,biotite quartz monzonite and monzonite.There are obvious contact boundaries between different lithologies,and the contact boundaries are flat,which may be due to the fact that another rock mass has not been completely consolidated when the rock mass is emplaced.The slopes of inactive elements P2O5-TiO2 and Zr-Hf are the same,and the ratios of La/Sm and Nb/Th vary within a narrow range,showing a near horizontal trend,which shows the characteristics of separation crystallization.The granitic complex may have evolved from the same magma chamber through separation and crystallization,and the granitic complex emplaced several times after the magma chamber evolution in a relatively short period of time.Most of the monzonite in the Baizhangzi complex is the direct surrounding rock of the granite-type orebody,and the syene-porphyry dike similar to the monzonite is formed relatively late and intersected in the rock body,and the age of the zircon is 230.74Ma.Rich in fluid and some sulfide,may provide fluid and ore-forming materials for mineralization,and is more related to mineralization.The rock mass is affected by alteration such as potassic,silicification,argillation,sericitization,pyritization,carbonation,and so on.Various alteration superimposed,the phenomenon of alteration zoning is not obvious,the rock mass in the ore-forming part is more broken,the alteration of silicification and pyritization is strong,and the alteration of argillation is weak.According to the mass balance calculation and Isocon diagram method,the ore body rocks are rich in SiO2,NaO2,Sr,Li,Ba and depleted in MnO,MgO,CaO,Y,V and Ni relative to surrounding rocks.The thermoelectric coefficient a of pyrite in Baizhangzi gold deposit ranges from-342.3?V/?to 344.3?V/?,and it is mainly of N-type and N-P type.Although the P type rate of pyrite in the altered rock type gold orebody is low,it still corresponds to the mineralization location.In the northern depth of the complex,the P type rate is higher and tends to extend to the deep.There is a positive correlation between pyrite dispersion and p-type rate,suggesting that the formation of altered rock type orebody was subjected to multiple hydrothermal processes.The formation temperature of pyrite mainly concentrates in 270?350?,and the temperature of the orebody is low,which indicates that the M1 orebody has a tendency to extend to the deep southwest,and the ore-forming potential is also high below the middle section of-30 in the north of the rock mass.The formation temperature of pyrite decreases from the deep part of SW to the shallow part of NW,suggesting that the ore-bearing hydrothermal fluids migrate from SW to NE.The formation of the ore deposit in Baizhangzi mining area is influenced by intrusive rock and structure,in which the late magma provides ore-forming material and fluid,and the structure controls the formation position of the ore body.Intensive silicification and pyritization are necessary conditions for the formation of altered rock type thick and large orebody in the mining area.The existence of fractures in rock mass provides a convenient way for the migration of ore-forming fluids.The wide development of small fractures in rock is also a favorable condition for such infiltration and metasomatism and mineral precipitation.The fracture of rock mass caused by tectonic activity and the existence of fault structure are the decisive factors for the existence of altered rock type thick and large orebody.The alteration rock type orebody is mainly affected by the F2 fault,which is mainly distributed above the gentle dip of the fault and at the steep dip height.Quartz vein type orebodies are distributed around it,among which the NW inclined quartz vein type orebodies deserve attention and can be used to predict the location of the altered rock type deposits.The three-dimensional visualization model of Baizhangzi ore deposit is established for the first time,and some data of the mine area are digitized and the database is established.Surpac software system is used to establish the surface model,fault model and orebody solid model of Baizhangzi gold mining area,which directly shows the occurrence of orebody,orebody and orebody,orebody and fault state in the real three-dimensional space.The 3d model is used to verify the ore-forming regularity,and the results are very good,which points out the direction for the next ore-prospecting.