The Analysis Of Geological And Exploration Geochemical Characteristics Of Duoergongma Antimony Deposits,Qinghai Province

Duoergongma antimony deposits in Q inghai province is located in the middle of the north Bayan Ha Au-Sb metallogenic belt in the lndosinan-Yanshanian stage(?19)(short for the north Bayan Ha metallogenic belt).At present,one superlarge deposit(Dachang gold deposit),two middle lardge deposits(Jiageilongwa gold deposit,Dongdatan antimony deposit)and three small deposits(Dongchenggongma gold deposit,Shanghongke gold deposit and Zhajiatongna gold deposit)have been discovered in the west of the metallogenic belt.But because of the natural conditions such as traffic and social environment,only a few small to medium-sized alluvial gold deposits and Au-Sb ore occurrences have been found Polymetallic ore prospecting work has yet to achieve greater breakthroughs.Based on the two found projects that is taken by No.6Armed Police Gold Geological Party in qinghai province:?Gold polymetallic mineral survey evaluation of Dulan-Tongde-Gande area in Q inhai province?and?Duoergongma gold deposit pre-survey in Maduo county,Qinhai province?,the paper made a comprehensive analysis to the geological features and exploration geochemistry characteristic of Duoergongma antimony deposits that is located in the middle of the belt.Compared with the deposit features of Dachang gold deposit and Dongdatan antimony deposit in the west of the north Bayan Ha metallogenic belt,the paper summarized the mineralization enrichment regularities,ore controlling factors,indicator for deposit and preliminarily discussed the genesis of ore deposits,and established the metallogenic model,which pointed out the prospecting guidance of polymetallic exploration in the east of the north Bayan Ha metallogenic belt with less work and and provided prospecting methods.Through this paper 's research and summary,the latest understanding and results are as following:1.The main stratum exposed in the mineral area is the Triassic Bayan Ha formation.And the group b is the main ore bearing stratum.The Maduo-Douge faults,which go through the mineral area,control the shape of the ore body and transport the ore forming elements.2.17 geochemical anomalies were marked in the Duoergongma Sb mineral area,which were composed of one first division ?anomaly,two second division ? anomalies,six second division ? anomalies and eight second division ? anomalies.No.6-9 Sb ore body were found in the HS? 129Sb(As Ag Au)anomaly area through geochemical soil survey in 1:10000 scale and trenching.No.1-5 Sb(Au)ore body were found in the HS?126Sb(Au As Zn)anomaly.Quartz veins associated with gold mineralization were found in the HS ?124Sb(Au As)anomaly.3.Nine Au-Sb mineralization alliterated belts,one Sb(Au)ore body and two Sb ore bodies were found in the Duoergongma Sb mineral area through a few trenching and one drilling project.The amount of the Sb forecasts resources(334)was 10462 tons and the deposit belonged to medium quantity of mineral reserves shall.Solidifications were very strong and closely associated with ore forming.Stibnite was the main metal ic mineral in the area.4.By the comparison of the ore controlling factors and genesis of mineral deposit o f Dachang gold deposit and Dongdatan stibium deposit in the west of north bay Bayan Ha metallogenic belt,we think that late Triassic to early Jurassic balyanlkalla ocean basin sub ducted northward and created orogenic activities,which leaded to the geothermal heating and drived metamorphic water migrating along the major fault.The metamorphic water extracted ore-forming material of the host rock,and finally formed the ore-forming fluid.The typical altered cataclastic rock type Sb-Au deposit was formed in the intersection of NWW faults and secondary faults,which is in the flysch sedimentary rock series of Triassic balyanlkalla mountain group of group b.5.The group b of the Bayan Ha formation was the main ore bearing stratum in the mineral area,which could be used as the indicator stratum for deposit.The secondary NWW,EW and NE structurally alliterated belt,occurred beside to Kunlunshankou-Maduo-Gande-Jiuzhi deep faults,were gainful for ore forming,which could be seemed as the structural indicator for deposit.The geochemical anomalies in different scales could be the direct indicator for deposit.Stibnite,pyrite,arsenopyrite and quartz veins could be the most visible indicator for the surface deposit.6.In this paper,the effect of the ore forecast was promoted in a great degree,through combining geochemical stream sediment survey with geochemical soil survey,comparing the ore character of the discovered mineral deposits,marking geochemical anomalies,and framing the indicators for deposit.The tight troubles,such as the inadequate geological exploration of the North Bayan Ha ore forming belt,the weak ecology,the sensitive National relationship,and the hardness for mineral prospecting,could be solved in some degree through reducing economic losses of the herdsman and reducing the destruction of vegetation in the greatest degree.