Characteristics,Ore-controlling Factors And Prospecting Direction Of Western Menglongshan Au-cu Polymetallic Mine,Inner Mongolia

Through detailed field investigation and comprehensive analyses on field geological survey data of the Western Menglongshan gold-copper polymetallic ore deposit,we discussed the characteristics of copper and zinc mineralization,and ore-controlling factors.By extracting information of ore indicators,we suggest that this area is a resource potential area.Further study on the above characteristics is meaningful for ore exploration in the Western Menglongshan and adjacent areas.The study area locates in the northeast margin of the Tarim Craton,and experienced multiple phases and stages of tectonic superimposition and reworking,providing good geological background for the transportation,accumulation and storage of ore-forming fluids.Archean to Cenozoic sequences are distributed in this area.Magmatism of different ages,especially Caledonian and Hercynian,were extensive in this area,and has close relations with the formation of gold-copper polymetallic ore deposit.So this area is a preferable ore-finding area.Two Cu-Zn mineralized bodies have been found in the study area,with lengths of about 200 m,and widths from 3 to 8 m,which were controlled by three exploratory trenches.Cu content is 0.59% in sample TC7-1H2,and 0.55%,0.48%,0.18%,0.17% in samples H5,H6,H9,H12,respectively.Zn contents in sample TC8-1H3-H24 is 0.18-0.4.%.Mineralization occurs in hydrochloride reef.In drill MZK8-1,apparent thickness of 6.7 m industrial copper ore body was discovered in depths of 114.26 to 120.96 m.The highest ore grade is 4.83%,with the range from 0.19% to 4.83% and an average of 1.75%.Preliminary prospecting results of the study area indicates that the Mahuagong-Western Menglongshan areas have good ore-forming geological background,with large scale,continuous ore mineralization,important type of industry,and should be the key exploration area in the next step.Through integrated analyses of geophysical and geochemical anomalies on AP4,combined with analyses on ore indicating information both on surface and underground,we suggest the resource potential areas in the deep,and proposed that No.1 and No.2 areas have better deep mineralization potential.Geoelectrochemical,high power tem sounding and deep drill methods should be applied to explore the deep ore bodies.Through a combined analyses on controlling action of structures,magma fluids,liquation of grabbro,diabase and mafic to ultramafic magmas,geophysical prospecting high magnetic anomaly zone,low resistivity and high polarizability IP anomaly area,geochemical Cu/Zn/Au association anomaly area,and alteration zoning characteristics,we summarized 7 ore-controlling factors,including strata,structures,magmatic rocks,lithofacies,geophysics,geochemistry and alteration.This study points out that the surface and superficial part of this area has no Cu-Zn forming potential.Based on the extraction of useful ore-indication information,the author predicted three resource potential areas,and discussed the oce-forming model.