Metallogenic Gwological Characteristics And Mineralization Of Yanweishan Copper-silver Deposit In The Grate Xing'an Mountainregion,Heilongjiang Province

Yanwei MountainCu-AgPolymetallic Deposits is situated on the Da Xinganling Mountainsmagmatic arcErguna subduction collision zone near the contact zone of huzhong-22 station volcanic rock zone and xinlinvolcanic rock zone, belong to xinlinpolymetallicmetallogenic subzone.Geological work of the past in the mining area control the orebody systematically, Find out the mode of occurrence of orebody and ore characteristics,the main aim is find out the orebody, control the orebody and find resources reserves and service the needs of social production,but it lacks systematic induction and summarization of the research on causes of metallogenic theory.This paper through the analysis to geological background and deposit characteristics combination with its characteristics of rocks, minerals, geochemistry,to establish mineral deposit model of Yanwei Mountain Cu-Ag Polymetallic Deposits,to provide the basis of analysis and forecast of resource potential and prospecting in the zone.The major exposure stratawithin the mining area is lower cretaceous of cretaceouslongjiang formation(K1l),guanghua formation(K1gn),guanghua formation rhyolitictuff and rhyoliticlava tuff breccia is the major ore-hosting rock.Magmatic rocks within the mining area is early cretaceous granite,after transformation of later structure events,rock localfragmentation and cementation again,exist in the form of fractured granites.The only potentialvolcanic rock can be see is granite-porphyry outcrop on northwest side in the mining area.The major tectonic is fracture,composition by nw-trendingfracture and trending near ns directionfracture, it is the major hydrothermalincreasedchannel and ore-occurrence structures. The major alteration types within the mining area is silicification,pyritization, carbonation, fluorition, sericitization, chloritization, kaolinization, nontronition, montmoriilonite, the alteration that is closely related to mineralization is silicification, fluorition, carbonation superimposed on face shapesilicification, pelitization.Combined with previous data,mineralized bodyin the mining area is alignment withhigh-resistancehigh-activationabnormal, Cu-Ag soil geochemical anomalies can show location of mineralized body basically.There are two metallogenic belt in the mining areanw-trending(?metallogenic belt)and ns-trending(?metallogenic belt),find 23 ore body(including parallel main orebody on hanging and lower walls ofmain orebody).The element is copper, silver and associated gold.The major occurrence of orebody is silicified breccia, the major metallic mineral is chalcopyrite, the second is tetrahedrite, porphyry copper deposits, covellite julianite, sphalerite, galena,the major texture of copper minerals is xenomorphic granular texture and metasomatic texture, the major structure is dissemination structure.The results of determination of sulfur isotope show that the ore-forming material may come from deep crust or upper mantle, the results of hydrogen and oxygen isotope show that ore fluid have a variety of sources. The major source is meteoric water,temperature constraints from fluid inclusions and component analysis show that ore-forming fluid temperature is low temperature,fluid property is low salinity low density solution major of sulphate and chloride.The results of comprehensive research of ore geological,alteration and mineralization characteristics,S element,O-H isotope characteristics and geophysical and geochemical characteristics of fluid inclusions show that Yanwei Mountain Cu-Ag Polymetallic Deposits is low temperature shallow-seated hydrothemal vein feature deposit which is with the relevant of mesozoicvolcanic rocksub-volcanic rock in the Xinganling Mountains volcanic rock zone.