Geological Characteristics And Prospecting Forecast Of Laodonggou Lead-Silver-Gold Deposit In Ejina Banner,Inner Mongolia

The study area is located in the territory of Ejinaqi,inner Mongolia Autonomous Region.The tectonic structure belongs to the eastern section of the Tianshan trough fold system(IV)-Beishan late Hualixi trough fold belt-the Hedashan complex anticline and the eastern tip of the ancient Gudongjing anticline,in the Inner Gutongjing-Heroshan Gold Metallogenic Belt of Baden-Jilin New Depression.On the basis of systematic collection of predecessor data,a large amount of first-hand information was obtained through actual participation in field work such as geological mapping,profile measurement,trench drilling project cataloging,and sample collection in Laojiaogou mining area.The geological characteristics of lead-silver-gold deposits in the study area are summarized from the aspects of stratum,structure,ore characteristics,mineralization alteration characteristics and geochemical characteristics of rock(mineral)rocks.The ore-forming geological conditions are analyzed and the metallogenic regularity is further discussed.The paper proposes a prospecting prospect,and achieves the following main understanding:(1)The lead-silver-gold deposit in the Laojiaogou research area is produced in the third lithologic section of the Xiayan Formation of the Jixian-Qingyinkou Formation of the Jixian-Qingyinkou Formation(Jx-Qny~3)in the dolomite marble which is layered output.The lithology is limonite mineralized dolomite marble.The ore body is mainly controlled by the northwest and north-northwest fault together with the east-west and near east-west fault.It is mostly vein-like,lenticular,and layered.The surrounding rock is strongly altered,and the main alteration is carbonation,jarosite,limonite mineralization,silicification,chlorite,pyrite mineralization,etc.(2)The deposit has ore-bearing hydrothermal fluid along the fissure filling ore-forming characteristics.The hydrothermal alteration mineral combination shows a combination of medium-low temperature characteristics.The pyrite bursting temperature closely related to gold mineralization is 250°C-370°C.The gold deposit is a medium-low temperature hydrothermal alteration-filled lead-silver-gold deposit controlled by structural fracture zone.(3)Geochemical results show that Au,Pb,Cu,Ag,As and other single element anomalies and comprehensive anomalies are closely related to gold mineralization which shows that even very low frequency electromagnetic method combined with high precision magnetic survey is an effective geophysical method in the mine.(4)According to the comprehensive analysis,the fractures around the I section and the IV section of the study area,the II section and the III section and the periphery of the V section,the deep F7 fault and the five normal fault zones parallel to each other are good prospecting prospects.