The Analysis Of Metallogenic Conditions Of Lead-Zinc Polymetallic,Pingandi Region,Chifeng,Inner Mongolia

The study area is located in the eastern Inner Mongolia,and located in the middle-southern part of Ulanhot-Bairin Youqi metallogenic belt.Geotectonic location is the xingmeng geosyncline and the North China platform two overlapping parts of the I-level tectonic units.It was experienced many cracking and split,and tectonic-magmatic activities are well developed,which Lead-Zinc mineralization are concentrated.The study of mineral mineralization in Pingandi and analys of metallogenic regularity are important for guiding follow-up survey deployment.The stratums mainly include Cambrian Amushan formation（C₂a）,Jurassic Xinmin formation（J₂x）,Manketourebo formation（J₃mk）,Manitu formation（J₃mn）,Baiyingaolao formation（J₃b）,Neogene Hannuoba formation（N₁h）,and Quaternary.There are widely multi period intrusive rocks in the study area.Rock type are exposeing from basite to acid and including some alkaline.Magma intrusion activities are divided into the middle Permian,the late Jurassic and the early Cretaceous.The main faults are the pressure（pressure-shear）.This is mainly realted to the north east of Sumutala pasture and Bayangaolegacha faults and belonging to derived or secondary structures.The main fold of study area is axial northeast of Kundulun flower of multiple secondary anticline.Through field geological survey and geochemical exploration and remote sensing data,and use of stratigraphy,structural geology,petrology research methods of comprehensive analysising,the main ore stratums are found in Amushan formation stratum and Manketourebo formation stratum.The former is related to the formation of the skarn magnetite in the contact area of the middle Permian,and the latter controls most Lead-Zinc polymetallic deposit in this area.The main mineralization era in this area is the middle Permian and the early Cretaceous.In addition to the diorite in the middle Permian,most of metallogenic rocks of each period are acid rock type in the early Cretaceous.The northeast trending faults in the area are closely related to the deposit.NW fault zone is related to the deposit,and the edge of the ring structure is related hydrothermal polymetallic mineralization.The wall-rock alteration mainly includes skarnization,silicification,sericitization,limonitization,strong chloritization,which are positively correlated with Lead-Zinc mineralization.Through the analysis of typical deposits,considered that the main deposits is related to undersea volcanic eruption-incursion in the middle Permian and west coast of the Pacific tectonic-magmatic events in the early Cretaceous.Magnetite and lead-Zinc polymetallic deposits are mainly formed in the middle Permian.Lead-zinc polymetallic deposits are mainly formed in the early Cretaceous.The types of ore genesis include hydrothermal metasomatic and hydrothermal fracture filling type and so on.