内蒙古额济纳旗格日勒图铜多金属矿成因及找矿潜力OA北大核心CSTPCD

The Zhusileng area in Inner Mongolia is the eastern extension of the Beishan metallogenic belt in China,and theGeriletu copper polymetallic deposit has been recently discovered in this area.This deposit was hosted in the volcanic rocks of the upper part of Upper Carboniferous Baishan Formation(C2b2).In order to study the genetic type of the deposit,this work analyzed the ore mineral fabric,ore geochemistry and quartz fluid inclusions,and conducted mineral electron microprobeanalysis.Results show that the gangue minerals in the ores are mainly quartz,the gas-liquid ratio of inclusions in quartz ranges from 15%to 40%,the homogenization temperature ranges from 156℃to 395℃,with an average temperature of 308.7℃.The salinity(wt%NaCl)ranges from 2.41 to 6.64,with an average value of 4.34.The ore-forming fluid belongs to low-salinity,medium-high temperature fluid.The gas inclusions in quartz can be divided into two types,i.e.,N2+CH4 type and N2 type.This deposit is indicated to be a magmatic hydrothermal deposit,and the copper polymetallic ore bodies display obvious vertical zonation.The upper part of the copper ore bodies develops high-grade secondary enrichment,with metal sulfides digenite,chalcocite,pyrite,sphalerite and small amounts of tennantite and chalcopyrite,and the lower part is mainly composed of pyrite,sphalerite,chalcopyrite,galena and tennantite.The formation of the deposit can be preliminarily divided into volcanic sedimentary diagenesis stage,magmatic hydrothermal mineralization stage and supergene mineralization stage.It is inferred that there is still a great prospecting potential in the deep part and peripheral areas of the deposit.