Geological Characteristics of Quartzite Deposits of Mesoproterozoic Heishantou Formation in Tadian Area,Eshan,Yunnan Province
Based on the 1:50 000 regional geological survey,typical profile and notch sampling,the Mesoproterozoic Heishantou Formation in the Tadian area of Eshan,Yunnan Province,has identified several layers of quartzite deposits with a thickness of approximately 104-227 m.The ore-bearing lithology is gray-white,ivory-thick layered quartzite,with aphanitic-granular metamorphic structure,mainly composed of quartzite(>95%).The analysis shows that the sample contains 95.15%-99.41%SiO2,0.21%-2.61%Al2O3,0.008%-0.047%CaO,0.088%-0.47%TFe2O3,0.009%-0.56%K2O,and 0.010%-0.13%MgO.The content of TiO2 is 0.011%-0.06%,which partially meets the industrial index requirements of siliceous raw materials such as glass and crystalline silicon.Heishantou Formation quartzite is an ore body with multi-layered occurrence and large monomer thickness,with a stable horizon and long extension.It is a set of coastal sedimentary metamorphic quartzite deposits with great potential value and economic benefits,and is expected to form a large-scale quartzite raw material-producing area in the future.