| Pangushan Tungsten Mine locates in the south of Yudu Country of Jiangxi province,Thirty-three kilometers away from the county town.It belongs to Pangushan town of Yuducountry.The regional stratums are secondary-kata metamorphic rock and the formation ofclasolite and carbonate rock of Devonian and Carboniferous, magma activity was very intenseand dyke is common in the zone, the metallogenesis had close relationship to the in the deep.Ore bodies exist in the Devonian,the outer contact zone of the granite in the Early Yanshanianstage.The deposit,which consists of south group,middle group,north group,relates toShigaowo fault intimately.the scale of south group is the biggest one and is miningmainly.The wallrock alteration is weaker,which includs skarnization,chloritization,sericitization,etc.The type of ore is wolframite-bismuthinite-quartz. The mineralizationprocess could be divided into three stages, silicate stage, quartz-sulfide stage and carbonatestage.The quartz-sulfide stage is the chief mineralization stage.The major ore minerals in Pangushan deposit are wolframite, bismuthine, scheelite,pyrite, molybdenite, sphalerite, chalcopyrite, pyrrhotite, gruenlingite,ect; gangue minerals aremica, quartz, potassium feldspar, aquamarine, cann, tourmaline,calcite and so on.The thesisresearch the composition and Standard type of the major ore and gangue minerals,such aswolframite, scheelite, bismuthine, pyrite, chalcopyrite, sphalerite, muscovite.So some ofconclusions was put forward.The main component of wolframite is manganese and tungsren ore in the area. theICP-MS analysis showed that Nb and Ta changes greatly, and the distribution is not uniform,but they have a positive correlations. Nb and Ta in the different position of the Mang3vein,the count has a reduce trend from deep to shallow(95â†'215â†'335), also changed greatly in thedifferent position of the same height, It reflects the ore-forming solution migration is not asimple change regularly along the vertical direction, it may has some different favorabledirection oblique insertion.The content of REE in the wolframite is quite different from eachother,the REE distribution pattern is left-leaning shapewhich reflects that the wolframite hasthe enrichment of heavy rare earths elements.But there is a little difference between orebodies,the content of the REE primarily increased and then reduce from the deep toshallow(95â†'215â†'335) in Mang3mineral vein,but the REE of wolframite in39vein hasdifferent REE distribution patterns and increase from level95metres to335metres.The research on crystal structure and composition of the major minerals shows that thecontent of CaO in scheelite is higher than the theoretical value,meanwhile,the one of WO3is lower than it and increases from deep to shallow. bismuth containing mineral is bismutiniteprimarily and a little native bismuth, galenobismuthite and chiviatite.The unit cell parameterof bismuthinite is lager than the theoretical value. Molybdenite is the type of2H1, it has twomainly forms. The component of pyrrhotite and marmatite indicates that they formed oncondition of high temperature.The analysis on REE in the minerals of different stages suggests that the Eu anomalyindicates the enviorment changed from closed one to opened one.The δEu-δCe diagram showsthat Tungsten mineral’s formation conditions is different from the sulfide, sulfide is formed atlate tungsten mineralization stage or high and medium temperature sulfide stage, formationorder is later than tungsten minerals.The data of wolframite is obviously different from theother minerals in ΣREE-LaN/YbNand∑(La-Nd)-∑(Sm-Ho)-∑(Er-Lu) diagrams.One of thereasons is the compatibility between the REE and the elements which consist the minerals,theother is the dephlegmation of REE in different stages,which indicate the metallogenesis ismultistage. Wolframite formed in early stage,the content of REE is higher than the otherminerals except scheelite, and that it’s rich of the heavy rare earths. |
PDF Full Text Request