Geological Characteristics And Ore-prospecting Direction Of Youfangxi Copper Polymetallic Deposit In Keshketen Banner,inner Mongolia

The Youfangxi copper polymetallic deposit in Inner Mongolia is located in the Xing'an Mongolia Orogenic Belt,east part of the Central Asian Orogenic Belt.It's near the southern marginof the Mesozoic volcanic rock belt in the Great Hinggan Mountains.Its basement structure is the eastern end of the Duolun anticline in the southernmost part of the Wenduermiao-Wengniutqi Caledonian geosyncline fold belt in the central part of Inner Mongolia.On the basis of previous work,field survey and comprehensive studies on the metallogenic geological conditions,alteration and mineralization characteristics have been carried out.This thesis also determines the genetic type of the deposit,summarizes the metallogenic regularity and prospecting criteria,and the prospecting direction by combining the data and information of geology,geophysical prospecting and geochemical prospecting.By using the method of combining field and indoor research,the following preliminary understandings have been obtained:Based on the analysis and study of the geological and geophysical characteristics of the deposit,it is found that the genetic type of the Yufangxi copper polymetallic deposit is magmatic hydrothermal vein deposit.The formation of the deposit is closely related to intermediate-acid volcanic rocks,and the metallogenic periodis late Yanshanian.Mineralization of the deposit is controlled by the NW-trending faults in the area.Ore bodies occur in regular veins with local branching and composite phenomena.The occurrence of the orebody is consistent with that of the fault structure(altered fracture zone),i.e.northwest and south-west.The dip angle of the first ore belt is steep,and that of the second and third ore belts is medium.Alteration fracture zone is the specific occurrence site of mineralization body.The banded red zone(hematite)and yellow zone(jarosite)are the direct prospecting indicators of mineralization area.Sericitization,silicification,fluorination and carbonation are closely related to mineralization,and they are the most direct and important indicators of the existence of ore bodies.IP anomaly and secondary halo anomaly in geochemical exploration are important indirect prospecting indicators.Through the analysis and study of ore composition and mineral distribution characteristics,it is found that mineralization distributes regularly along the horizontal direction.Silver,lead and zinc distribute all over the area,while copper only appears in the middle part.Vertical direction,silver and lead-zinc mineralization dominates in the upper part,and copper mineralization gradually strengthens in the deep part.In summary,there are great ore-prospecting potentials in the depth,lateral extension and the surrounding of the deposits.