Ore-forming Geological Conditions And Prospecting Direction Of Au,Sb And Polymetallic Deposits In The Ershiwuzhan Area,heilongjiang Province

The study area is located in the Daxing'an Mountains-Mongolia folded region in "Ergun Block",composite area of Ergun swell,Heilongjiang dent and Greater Khingan Mountains volcaniczone,at the linkage between the middle of Mohe nappe and the 21 station metallogenetic belt.Gold and multi-metal ore desposits has been found,which include ergen-river gold desposits,Shabaosi gold desposits,Yesuoku gold desposits,Laogou gold desposits,Daleizishan antimony deposit,Maojiadagou gold spots,Aolaqi-river gold spots and so on.The existing study and exporation show the good Minerogenic geological conditions,obvious ore-prospecting indications,and huge potential of gold antimony and Polymetallic ore prospecting.The study of ore-forming geological conditions and exploration direction forcarsting is significance for subsequent ore prospecting.There exists a great area of feldspathic litharenite,lithic arkose,lithic sandstone,conglomerate siltstone,a small amount of andesite,which is formed from upper-middle Jurassic Mohe formation in the study area.Intrusive rock is not developed,dike rocks like diorite and quartz porphyry can only be found there.The whole area is in the frontal zone of Menduli and Ershiwuzhan in Mohe nappe.It's manly formed by NW-trending ravines fractures,and second by NE-trending fractures.Around the stuy area,daleizishan-antimony and gold deposit are developing,which two are located in the south of Maojiagou-daleizishan fracture,ore bodies exist lithic sandstone and sandy slate from upper-middle Jurassic mohe formation.Daleizishan antimony ore is in the west of the study area,there,3 antimony ore,6 antimony mineralization ore,1 gold deposit and 7 gold mineralization bodies have been discovered.Maojiadagou gold deposite is in the distance of 20 m in southwest of the stuy region,there are 3 gold deposits,7 gold mineralization body and one antimony ore have been detected.Until now research had shown that gold and antimony mineralization has a close relation with strata of upper and middle Jurassic Mohe formation,which is the main place for gold and antimony mineralization.Mohe nappe is an active tectonic region with intensive compression and local tension.It had provided the advantageous space for metallogenic hydrothermal activity,moving and ore-fluid precipitation.in a word,Maojiagou-daleizishan fault and its secondary structures are very important for ore leading and hosting.Comprehensive research result shows that,carbonatization,silicification,pyritization,limonitization in the lithic sandstone closely related to ore-forming.The more intensive it alterate,the more strongly the gold and antimony mineralizated.Alterate of silicification,pyritization and limonitization is the geological sigh of gold searching.alterate of carbonatization and silicification is the geological sigh of antimony searching.Association anomaly of soil anomaly in large area and obvious concentration zoning are very important mark for finding gold.Obvious single element anomalous and concentration zoning in large area are main sigh for seaching antimony,especially in the high value region of antimony element.After Processing and analyzing of geophysical data,there is a banded magnetic anomalies in the north and south search area,there are 7 abnormal parts which character of high in chargeability,2 abnormal part of high apparent resistivity.Through the treatment and analysis of the 1:20,000 soil measurement anomaly data,and the comparison between the adjacent mining areas,the main ore prospecting in this area is Au and Sb.On the basis of the abnormal analysis of metallogenic elements,77 single element anomalies and 13 combination element anomalies were delineated.Combined the development degree of Minerogenic geological conditions and the obvious degree of prospecting indications,especially the alteration features of carbonatization,silicification and pyritization,with the abnormal of ore-forming elements association and IP anomalies,3 areas for predicting and 2 targer area of prospecting have been located,which provide important foundation for coming exploration.