Metallogenic Background And Prospecting Criteria Of Lead Polymetallic Ore In Xiaodonggou,Arhorqin Banner,Inner Mongolia

Xiaodonggou lead-polymetallic metallogenic area is located in the eastern end of the North China Plate(Grade I tectonic unit)-North China marginal accretion zone(Grade II tectonic unit)-Baoyintu-Xilinhot volcanic passive continental margin(Grade III tectonic unit).The strata exposed in the study area are mainly the middle(J3mk2),upper(J3mk3)and Quaternary of the Upper Jurassic Manketou Obo Formation.The magmatic rocks are mainly grey-white medium-fine grained plagioclase granite and grey granite porphyry of late Yanshanian.The main part of the structural line in the study area is NW,and the fault structures are well developed.The ore bodies of Xiaodonggou lead polymetallic deposit mainly occur in the granite porphyry and diorite dike development areas in the central and northern part of the study area.The ore bodies are strictly controlled by a series of nearly parallel NW-trending fissure zones,and some are controlled by NW-trending and EW-trending fissure structures.Ore bodies occur in veins and host rocks are breccia tuff,granite porphyry,diorite and plagioclase granite.Most of the orebodies are NW-trending,and the dip angle is 60-82 degrees,mainly NW or NE.The length of the orebody is 31-190 m,the inclined depth is 50-224 m,the thickness is 0.88-3.47 m,the depth of the orebody is 0-258 m,and the ore-hosting elevation is 490-164 M.The wall rock alteration of Xiaodonggou Lead Polymetallic Mine is mainly medium-low temperature hydrothermal alteration.There are silicification,chloritization,epidermis,carbonation,pyritization,clayification,iron-manganese mineralization,fluorination and so on.Among them,silicification,chloritization,epidermis and carbonation are the most developed and closely related to mineralization.Based on the comprehensive analysis of the geological,geophysical and geochemical anomaly characteristics of the ore(chemical)body in the study area,the ore-forming geological and geophysical and geochemical anomaly characteristics of the known ore(chemical)body are summarized,combined with the data of similar deposits in the area.the prospecting criteria in this area are preliminarily summarized to provide a theoretical basis for follow-up exploration in the study area.