【摘要】 利用Sm-Nd同位素定年和稀土元素对后长川钨矿的白钨矿进行分析等手段研究,结果表明:白钨矿Sm-Nd等时线年龄为399.0Ma±9.2Ma,白钨矿的稀土配分模式曲线呈明显的中稀土(MREE)富集型,Eu正异常较明显,表明其形成于富钠的热液中,REE3+与Na+组合以化合价补偿形式有选择性地置换白钨矿晶格的Ca2+。白钨矿成因为石英脉型,成矿物质来自围岩,岩体可能更多地表现在为成矿提供热源,加热流体通过淬取地层中物质成矿,其成矿可能与祁连地区加里东末期区域构造热事件关系密切。更多还原

【Abstract】 Research on the Sm-Nd dating of Scheelite and its REE compositions from Houchangchuan scheelite deposit in Gansu Province showed that Sm-Nd isotopic isochron age of the scheelite was 399.0 Ma±9.2 Ma,and the scheelite mineralization took place in the Late Caledonian period in association with the tectonic heating event occurred in Late Caledonian movement in the Qilian area.The chondrite-normalized REE pattern display MREE enrichment and positive Eu anomaly,suggesting that the scheelite was generated from Na+ enriched hydrothermal fluid.REE substituted into the Ca site of scheelite by charge compensation mechanism(REE3++Na+=2Ca2+).The genetic type of ore belongs to quartz vein type and ore-forming materials came from wall rocks.Magmatic activity provided heating resources for the ore solution which enabled the heated fluid to extract ore-forming elements from the wall rocks.更多还原