Geological Characteristics And Metallogenic Prognosis In The Bulage Pb-Zn Deposit,Dong Ujimqin Qi,Inner Mongolia,China

The Bulage Pb-Zn deposit in dong ujimqin qi,inner mongolia,loeated in the Chaganobo-Aououte-Chaobuleng along the southern edge of the Siberian Plate,lies in western of Greater Xing'an Mountains metallogenic belt,which is one of the most important metallogenic belts in China,hosting numerous Mo,Au,Fe,and Pb-Zn-Ag deposits.A number of Pb-Zn deposits have been discovered in this belt,making this area to be an important Pb-Zn-Ag producer throughout the North China Craton.However,there is some confusion on the deposit type,fluid evolution,materials source,tectonic setting of these deposits,especially several issues remained unresolved and merited further study,i.e.ore-forming fluid system,Pb and Zn metallogeny and mineralization potential in bulage.This paper systematically studied ore deposit geology,geochemistry,age of rock-forming and mineralization,origin of ore-forming fluids and materials in the bulage Pb-Zn deposit from Greater Xing'an Mountains metallogenic belt,to reveal the genesis of this deposit and further make metallogenic prognosis for this mining area.The ore bodies from Bulage Pb-Zn deposit,are hosted in granodiorite,diorite and granite porphyry controlled obviously by the fracture in Dong Ujimqin Qi,Inner Mongolia,China.The ore-forming process can be divided into hydrothermal and hypergene stages.The hydrothermal ore-forming process can be divided into three stages: quartzspecularite stage,polymetallic sulfide stage and quartz-low-sulfide stage.Ore minerals and Lead and Zinc mainly occurred in the second stage.The homogeneous temperatures of the fluids in the hydrothermal three stages are mainly 119~315°C,143~230°C,119~172.4°C respectively,with salinities ranging from 3.2%~9.5% NaCleqv,2.6%~8.3% NaCleqv,3.2%~6.6% NaCleqv separately.The fluid inclusions in the Bulage Pb-Zn deposit are characterized by low temperatures and low salinities.The mixing of meteoric water resulted in rapid precipitation of ore-forming materials.It is believed by investigating that the ore-forming fluid was derived mainly from meteoric water with rock formation water,and ore-forming material from granodiorite and diorites provided a heat source for the formation of this deposit.The mineralization age is measured by using zircon U-Pb dating to be 300~290Ma,which means that this deposit was possibly formed during Late Carboniferous to Early Permian by multiple subduction of the Paleo-Asian Ocean.Considering the formation of this deposit,it is attributed to epithermal deposit determined by meteoric water and low-temperature mineralization.Based on the detailed study of the Bulage deposit,it finds that the ore bodies of Bulage deposit is controlled by the faults and magmatites such as diorite,diorite porphyrite granodiorite,and granite porphyry.The most important prediction symbol in Bulage mining area is edge of diorite and diorite porphyrite.The edge of diorite and diorite porphyrite,tectonic site and geophysical-geochemical exploration abnormalies show a better Pb-Zn mineralization potential.According to geological characteristics,geophysical and geochemical anomalies,this paper delineates four prospecting target areas in the central and southern regions of this mining area,which will be helpful for the further study in Dong Ujimqin Qi.