The Geochemiscal Characteristics And Genetic Analysis Of Shiziyan Tungsten(molybdenum) Deposit, Wuning County,jiangxi Province

It is located in the east-southern of the area that is Dahutang deposit-concentrated that is Shiziyan tungsten(molybdenum) deposit at Wuning county in Jiangxi province,and it has been discovered the large scale deposit in recent a few years. Based on analysis on the geological backgroud and the geological characteristics in this paper, through systemacally collecting the sample of rock and ore, it is studyed in rock geochemistry,the type of alterative rock and discriminal belt, the fluid inclusion and isolope geochemistry and so on, in order to discuss the case of element immigration, the ruler of enrichment and minerale mechanism of deposit, though establised the model of mineralization of deposit, and obtained following conclusions:1. Based on the analysis of geological background and geological characteristics of the deposit, the ore-body is controlled by explosive breccia in the shape and genesis.minerals are mainly scheelite and molybdenite, and so on, it is formed in the quartz veins that is crack or gaps between breccia and rock.2. Jinling period granite is the wall rock of ore-body, it is a series of granites rich peraluminous and rich K and calc-alkaline, is formed by pelitic rock of Neoproterozoic Shuangqiaoshan group that is remelted. Large ion lithophytes element such as Li、Rb is related enrichment and the high field strength elements or imcomparmental elements suck as W、U、Nb、Ta is low; the element of related Cu or S such as Cu、Pb、Zn is middle.The REE distribution patterns are obviously shape of “V” toward right slipe, the content of REE is total high, the light rare element is enrichment but weight rare element is reduced, δEu=0.51,the element of Eu is loss.3. The alterative rock obviously enrich silicon, potassium, calcium, but lack of iron,sodium. Silicon and potassium is put into rock but iron and sodium is put out of the rock.The element of related Fe such as W, Mo is a strong enrichment, the element of W, Mo,Nb, Ta is put into rock but the one of Ba, Th, Pb and so on is put out of. The content ofREE is total low, the fractionation is obvious between LREE and HREE, both LREE and HREE is loss, δEu=0.57, the element of Eu is loss, and overall move out.4. the mineralizated period is devided into three period that are potassium-greisenization perion to metal sulfide phase and then it is scheelite-calcite period from early to later. Based on study about the fluid inclusion and has shown: there is a tendency of gratually decreased with homegenizational temperature, that is from(276.7~288.2℃) to(214.3~225.3℃) then(163.4~177.9℃), on the salinity changes, it has a tendency of gratually rised instead of gratually decreased with homogenizational temperature, that is from(5.9% ~ 7.2%Na Cleqv) to(8.6% ~ 10.3%Na Cleqv) then(11.55%~13.10%Na Cleqv). The fluid density is between 0.57~0.94g/cm3, it’s between1.42~1.76 Km in the mineralizational depth.5. The content of δ34S in deposit’s sulfides is-1.6‰~-1.7‰, with an average is0.95 ‰, it is closely to the mantle’s dateing, It shows S derive mantle.Above study and shown: it is a typical deposit of hydrothermal breccia, the structure environment that is extrusion- stretching action offer power source and channel of magma and fluid(transport); magma is located position and exploded, the covered rock form breccia, it offered space of store for mineralization material(store).