Geological Characteristics And Prospecting Direction Of Dadiangou Gold Deposit In Longnan Area Of Western Qinling Region

Longnan area is located in the famous "Shaanxi Gansu Sichuan" China Golden Triangle metallogenic zone,which also be located in the western of Qinling orogenic belt and north rim of Bikou's contact zone,three different tectonic units of the North China plate,the Yangtze plate and the Songpan block.In recent years this area have found more than 10 large and medium-sized gold deposits,gold point dozens,gold ore prospecting potential is very great.However,the research on these gold deposits(points)is mostly concentrated in the stratigraphic division and tectonic environment,the geochemical characteristics of the rock mass,the formation of the age and so on,the research of the typical deposit is not systematic and thorough.Dadiangou gold deposit is a representative medium-sized deposi which is found in the area in recent years.This paper relies on the nuclear industry in the Northwest Economic and technical preparation of the company at dadiangou gold mine project survey data,Changchun Gold Research Institute for the ore beneficiation test report for all relevant information as well as the region,field geological investigation,microscopic identification,electron microprobe analysis,rock ore appraisal analysis.At last,we summed up the region stratum,structure and wall rock alteration for prospecting guide the prospecting ideas and direction.The main achievements are as follows:(1)Forming geological background of Dadiangou ore: Yangtze plate and the North China plate collision occurred in late Triassic,the Indosinian acidic rock mass are formed.Due to the well developed structure,gold element migration and enrichment.Finally it formed many gold deposit in the area.(2)The ore bearing strata at Dadiangou gold deposit is Sinian Ordovician-Danfeng Group,distribution of ore deposits are mainly controlled by structure(fault).Yuan Jia Ping-Xiaosi Gou ductile shear zone is leading the ore structure.A number of small secondary ductile shear zone(brittle)next to the formation are ore bearing structure,they control the ore distribution,shape and size.(3)Dadiangou gold deposit is judged for the medium from the preliminary investigation.The ore body mainly are stratoid,lenticular,Along strike and dip direction there is still a prolonged and deep,rock type includes two types: tectonic altered rock type and quartz vein type.The key of gold mineralization in a quartz veins or altered rock is whether the distribution of pyrite.(4)The most direct ore prospecting marks are silicification,pyritization and sericitization alteration.The most common development is silicide,pyrite as an important gold bearing mineral,often with lumpy,fine grained,or fine veinlet filling in quartz vein and altered rock fracture which has close relationship with gold mineralization.Sericite(fade alteration)with gold mineralization are very close relationship,the gold mineralization occurs almost exclusively in fade alteration belt.(5)According to the metallogenic model of metallogenic mechanism,alteration characteristics,ore body characteristics can be established at Dadiangou gold prospecting...