【摘要】 西藏甲玛铜多金属矿床位于冈底斯成矿带中段,矿区内显示钨元素异常,局部矿化富集,但前人尚未对钨元素及钨矿物进行研究。为弥补该空缺,文章通过分析钨含量随孔深变化的关系、钨矿物显微镜下鉴定和电子探针分析,发现甲玛矿床矽卡岩型矿体的深部易于富集钨,且出现波峰,钨含量明显高于中浅部矿体;甲玛矿床中的钨矿物为白钨矿,主要赋存于矽卡岩中,且分布不均匀,颗粒细小,需要通过显微镜下鉴定才能识别,其中,与白钨矿共/伴生的矿物以矽卡岩矿物为主,包括钙铁榴石、硅灰石和透辉石等。甲玛白钨矿的WO3和CaO含量较理论值略偏低,并含极少量P2O5、K2O、FeO、MnO、Cr2O3和NiO等杂质。作者认为甲玛矿区的钨矿物主要为白钨矿,不利于形成黑钨矿。冈底斯成矿带发育众多矽卡岩型铜钼多金属矿,矽卡岩型矿床中钨矿化/异常的陆续发现,指示了冈底斯成矿带上良好的找钨矿前景。更多还原

【Abstract】 The Jiama copper polymetallic deposit,located in the middle part of the Gangdese metallogenic belt,has tungsten anomalies and local enrichment.However,very insufficient research work has been devoted to tungsten and tungsten minerals.In order to make remedy in this aspect,the authors probed into the variation of tungsten content with the depth,and made microscope identification and electron microprobe analysis.The results show that tungsten in Jiama is concentrated in the deep skarn type ore body rather than in the middle and shallow ore body.Scheelite is the only tungsten mineral found in Jiama and occurs as very fine grains in the skarn,which have to be identified by microscope.Mineral assemblages related to scheelite are such skarn minerals as andradite,wollastonite and diopside.WO3 and CaO contents in scheelite from Jiama are a little lower than their theoretical values because scheelite in Jiama contains very small amounts of P2O5,K2O,FeO,MnO,Cr2O3 and NiO.Therefore,the authors hold that there is only scheelite in Jiama,with no wolframite existent.Tungsten prospecting is promising in Gangdise,as evidenced by the continuous discovery of tungsten anomalies/ore spots in the skarn-type Cu-Mo polymetallic deposits.更多还原