Geological Characteristics Of Ore Deposits Study In Er Daohe Silver-lead-zinc Deposit,Inner Mongolia

Er Daohe silver lead-zinc deposit is located in Chai He,Zha Lantun City of Inner Mongolia.It is a large-scale skarn-type deposit discovered in recent years in Da Xinganling metallogenic belt.Due to the weak geological exploration work,some basic geological problems such as mining strata,magmatic rock characteristics and age are lack of sufficient understanding,and there are few studies on magmatic rocks related to mineralization.Different scholars have different understanding of the geological characteristics and genetic types of the deposit.In this paper,through the study of regional geological characteristics,combined with field research,and the collection of rock(mine)stone specimens for indoor research.A series of scientific studies on the determination of zircon U-Pb,the study of fluid inclusions,the C-H-O isotope test and the S-Pb isotope test have been carried out under the microscope.Er Daohe silver lead-zinc deposit is a typical skarn type lead-zinc mine,which is found in the middle-upper Ordovician bare river strata.The alteration of the surrounding rock is characterized by the development of the skarn,and the alteration zonation is obvious,from the ore body outward to the lacquered garnet skarn zone ? the greenstone skarn karst zone ? the green pan Rock zone.The zircon U-Pb ages of steep rock and granite porphyry are(145.0 ± 1.6 ? 139.1 ± 1.8)Ma,(133.7 ± 1.2 ? 132.9 ± 1.6)Ma,respectively,which indicates that the intrusive rocks formed in Yanshan Late(early Cretaceous).The diatomic elements of Rb,Ba and K are enriched in the Dadaohe mining area,and the K content is positively correlated with the content of light rare earth,and the high field strength elements such as Th,U,Nb and Ta are strongly depleted,which may be part of the mantle The contents of Th,U and K in granite porphyry are higher than those of K,Th,U,La,Ce,Zr,Hf,Rb and Yb,and Ba,Sr and Nb,Ti,P and other elements,suggesting that the rock is crustal source or in the evolution of the crustal material by the mixing,magma partial melting or crystallization process may be plagioclase,biotite,apatite,ilmenite Separation of minerals.The results show that the salinity changes from 0.35% to 12.90% NaCleqv with the decrease of the mineralization temperature from the skarn stage to the quartz sulfide stage.At the low temperature stage(quartz-Carbonate level),salinity significantly lower,low temperature salinity in the 4.18% ? 0.35% NaCleqv,indicating that the temperature is the main reason for the precipitation of minerals,and the late mineralization may have more groundwater mixed.The H-O and C-O isotopic data show that the ore-forming fluid is derived from magma and is a mixed fluid of magmatic water and atmospheric precipitation.S and Pb isotopic data show that the ore-forming material is derived from magma and may contain mixed material in the process of mineralization.