Synthetic Information Prediction Of Gold And Polymetallic Deposit In Donggang Area,Linjiang City,Jilin Province

Donggang area is located in the northern edge of the Sino Korean platform and the Liao Ji Rift Valley,North West of the Korean Peninsula,belonging to Nancha –Huanggoushan Au,Ag,Cu,Pb,Zn,Sb polymetallic prospecting area of YingkouChangbai(secondary uplift)Pb-Zn-Fe-Au-Ag-U-B metallogenic subzone,Liaodong(uplift)Fe-Cu-Zn-Au-U-B III metallogenic belt.The metallogenic belt has great metallogenic geological conditions,and a number of polymetallic minerals have been found so far.Under influence of large area of the Neogene basalt and the thick vegetation on the surface,the degree of geological research in Donggang area is low.Therefore,the comprehensive information prediction work is carried out,expecting to make significant breakthroughs in metal mineral exploration.This paper is based on the " gold and polymetallic ore advanced investigation in Donggang Village,Linjiang City,Jilin province " project.Through the study of Donggang regional metallogenic background,mineralization geological conditions,various indicators and typical deposits,the metallogenic regularity and model are summarized,comprehensive prospecting information is extracted and a comprehensive ore prospecting model is set up.Then delineating comprehensive prospecting target area and target area optimization and implementation of engineering verification at the same time are carried out to point out the direction for the next step of prospecting.In Donggang area,the strata closely related to mineralization are Paleoproterozoic Zhenzhumen group.The intrusive rocks related to mineralization are Yanshan quartz diorite and granite porphyry.The structures related to mineralization are NE or near EWYalu River faults and secondary faults.Mineralization is often located at the turning point of the fault structure,branch compound part of the fault,the intersection of multiple faults,and the contact zone between intrusive rocks and strata.Comprehensive prospecting information in the study area shows that there are mineralization clues at contact parts of Yanshan period acidic rock and Paleoproterozoic Zhenzhumen group marble in Donggang area.Silicification,serpentine,skarn,peacock fossilization,pyrite mineralization,and ferritization are found near the contact zone.Most of the structures in the area are covered by Quaternary basalts.Interpretation by remote sensing,the main faults are NE or near EW trending faults.Enrichment coefficient,variation coefficient,skewness of soil geochemical survey data analysis shows that the elements of Au,Ag,Cu and Pb have the tendency of local enrichment.To identify the main metallogenic elements in the region,correlation analysis,cluster analysis and factor analysis were used,and the combination of elements were further revealed.At the same time,combined with the feature of single element anomaly,combination anomaly characteristics and metallogenic geological background in Donggang area,a total of eight comprehensive anomalies were delineated.Abnormal of ip intermediate gradient shows that the main characteristic of IP anomaly is "relative high resistance and high polarization" in zone I and the characteristics of zone II and III are "low resistance and high polarization".Analysis of deep anomaly geoelectric structure by sounding indicates and understanding the characteristics of Isoselectric anomalies that may be related to the mineralization aleration zone,It is confirmed that DHJ-3,DHJ-4,DHJ-7 and DHJ-10 are important ore prospecting areas,having potential for further prospecting of deep concealed orebodies.There are different sources of deposit forming materials in different genetic types in the area.The mineral formation of skarn type deposits mainly comes from the mantle,with a small amount of crustal material mixed in.However,the mineralization of the middle-low temperature hydrothermal deposit is only related to the crustal material.But the spatiotemporal distribution is similar to the same.Both are controlled by the YaluRiver fault,and the spatial distribution pattern is nearly NE direction.The ages of mineralization are mainly in the Yanshan period of Mesozoic.There may be hydrothermal type and skarn type deposits similar to typical ones' metallogenic conditions in Donggang area.Under the guidance of ore prospecting model of metallogenic prediction theory,combined with geological reconnaissance,geochemical and geophysical prospecting information obtained in Donggang area,prediction of concealed ore body were carried out.3 comprehensive target areas of different levels were identified in the area,by which 1 level I and 2 level II are selected.For possible ore bearing area,trenching engineering verification was carried out,finding a copper mine spot.