【摘要】 赣西北大湖塘钨矿具有低品位、大储量、热液蚀变强等特征。在热液蚀变类型和空间分带特征的厘定,以及富锂-云母矿物学特征的认识基础上,通过云母类矿物原位主微量元素组成特征的分析,揭示大湖塘钨矿锂等稀有金属元素的富集,可能是大量热液成因黑鳞云母、铁锂云母和锂-多硅白云母的先后沉淀叠加聚集的结果。其中铁锂云母的锂元素含量最高（Li₂O=4.15%～4.86%）,黑鳞云母（Li₂O=0.81%～1.72%）次之,然后是锂-多硅白云母（Li₂O=0.24%～0.45%）。大湖塘钨矿富锂-云母在蚀变岩中比例非常高,分布又均匀,而蚀变岩的规模更是巨大,因而具有巨大锂等稀有金属成矿的潜力。典型蚀变岩的全岩主微量元素分析显示,在晋宁期花岗闪长岩黑鳞云母+铁锂云母蚀变带的锂、铷和钾等元素含量最高。即富钾热液蚀变岩,其K₂O=5.94%～8.06%,Li₂O=0.34%～1.548%和Rb₂O=0.175%～0.784%,而黑鳞云母+铁锂云母+石英蚀变则次之。在燕山期花岗岩中,则以锂元素富集为主,铷含量相对偏低。高含量样品主要集中在钠化带,其Na₂O=5.79%～6.17%,Li₂O=0.902%～1.034%和Rb₂O=0.140%～0.213%,而锂-多硅白云母+石英的蚀变岩则相对略低。大湖塘钨矿燕山期花岗岩以多期多阶段的脉动活动为特征,特别是晩阶段相对富锂、铷和钨,这是大湖塘钨矿锂、铷和钨富集成矿的物质基础。对比雅山钽锂矿和赣南钨矿的蚀变空间分带特征,我们进一步探讨了铌钽矿、锂铷矿和钨矿之间的岩浆-热液演化过程,即铌钽矿以结晶分异为主,锂铷为结晶分异和碱性热液阶段,最晚的是钨矿的酸性热液阶段。认为赣西北地区乃至华南,着重对热液蚀变空间分带的厘定,特别是在钨矿深部内接触带的云英岩化和钠长石化带,是寻找富锂-云母化蚀变岩型锂铷多金属矿重要标志,即"就钨找锂铷"。这可能是稀有金属找矿突破的重要方向之一。大湖塘钨矿富锂-云母类的巨量富集成矿及其富集过程,是本次研究工作的重要发现,也将是大湖塘钨找矿认识的重要突破。更多还原

【Abstract】 In recent years, a series of rare metals and tungsten prospecting breakthroughs have been made in the northwestern Jiangxi. Especially, the Li-Rb enrichment and mineralization were reported for the first time in the Dahutang giant tungsten deposit. It shows an obvious distinction, probably a genetic relationship between the W and Li-Rb deposits. The Dahutang tungsten deposits have a characteristic of low grade, high tonnage, and strong hydrothermal alteration based on the identification of mineralogy of Li-mica and hydrothermal alteration type. The hydrothermal Li-mica are zinnwaldite（Li₂O=4.15%～4.86%）, protolithionite（Li₂O=0.81%～1.72%）, and Li-phengite（Li₂O=0.24%～0.45%）. We chose 47 altered hand specimens for whole rock geochemical analysis. Research shows that lithium mineralization is mostly responsible for the enrichment of Li-mica in the Dahutang tungsten deposit. The protolithionite and zinnwaldite altered Neoproterozoic granodiorite samples have a characteristic of high concentration of K₂O（5.94%～8.06%）,（Li₂O=0.34%～1.548%） and Rb₂O（0.175%～0.784%）. However, the trilithionite, paragonite and albite Yanshanian altered porphyritic biotite granite have a characteristic of high concentration of Na₂O（5.79%～6.17%）,Li₂O（0.902%～1.034%）, and Rb₂O（0.140%～0.213%）. Significantly, the unaltered Yanshanian granites have a characteristic of multi-phase magmatic activity, but all are enriched in Li, Rb, and W. Potentially, further enrichment and mineralization occurred due to hydrothermal fluid circulation. This work demonstrates a precipitation sequence from the magmatic Nb-Ta mineralization to Li-Rb, and finally to the W-Mo hydrothermal deposit. The preliminary study could provide a new direction for the regional and deep prospecting of rare metals in the tungsten deposit at the northwestern Jiangxi.更多还原