广东始兴良源铌钽铷钨多金属矿床的发现及其意义

Discovery of Liangyuan Nb-Ta-Rb-W-polymetallic deposit in Shixing county,Guangdong Province and its significance

广东始兴良源铌钽铷钨多金属矿床是近年来中国地质调查局在南岭东段地区实施钨多金属矿调查评价中找到的具有大型远景的铌钽铷钨多金属矿床。最新成果显示该矿床主要有五种矿化类型:云英岩型铌钽铷钨多金属矿、白云母化钠长石花岗岩型铌钽铷钨多金属矿、石英脉型钨矿、破碎蚀变岩型钨锡多金属矿和矽卡岩型白钨矿,且以白云母化钠长石花岗岩型铌钽铷钨多金属矿潜力最大。矿区含矿花岗岩具明显分异演化特征,自上向下为:似斑状花岗岩—中细粒黑云母花岗岩—中细粒二云母钠长石花岗岩—中细粒白云母化钠长石花岗岩—云英岩的分异演化系列;含矿花岗岩蚀变分带清晰,自上向下为:白云母化、绿泥石化和钾长石化三带,矿体以云英岩、细粒白云母化钠长石花岗岩为主,石英脉次之,矿石矿物主要有黑钨矿、白钨矿、锡石、辉钼矿、钨铅矿、钼铅矿、砷铋矿、辉铋矿、辉锑矿、褐钇铌矿、铌钽矿、方铅矿、闪锌矿、黄铜矿、黄铁矿、铀钍矿、白云母等;初步研究表明广东始兴良源铌钽铷钨多金属矿体可能为深部含矿岩浆经分异演化形成,矿床具有品位稳定、规模大的特点,成矿元素复杂,主要为Nb-Ta-Rb-W-Mo-Sn-Bi组合,并富含Be、稀土、Ag等。该矿床的发现不仅填补了南岭东段地区找矿新突破,而且对整个南岭乃至华南地区铌钽铷钨多金属矿找矿具有重要的指导作用。

The Liangyuan Nb-Ta-Rb-W polymetallic deposit in Shixing county,Guangdong Province,a deposit with a prospect of large scale,was found during the new-round investigation of tungsten polymetallic ores in the eastern Nanling mineralization zones deployed by China Geological Survey（CGS）in recent years.The new results show that five mineralized types can be recognized in the deposit,namely,greisen-type niobium-tantalum-rubidium-tungsten polymetallic ore,muscovitization albite granite-type niobium-tantalum-tungsten polymetallic ore,quartz vein-type tungsten ore,fractured belt alterated rock-type tungsten tin polymetallic ore and skarn-type scheelite,among them,muscovitization albite granite-type niobium-tantalum-tungsten polymetallic deposit shows the most prospective potential of exploration in this area.From the top level downwards to the deeper of the ore-bearing granite,the following differentiation evolution series are successively observed： porphyritic granite,medium-fine grained biotite granite,medium-fine grained two-mica albite granite,medium-fine grained muscovitization albite granite and greisen.In addition,alteration zoning,including muscovitization,chloritization and potassic alteration,is evidently observed in the ore-bearing granite.The ore bodies mainly occur in greisens,and fine grained muscovitization albite granites,and secondarily in quartz veins.The major ore minerals are scheelite,cassiterite,wolframite,molybdenite,bismuth,stibnite,fergusonite,fluorine-tantalum minerals,columbotantalite,galena,sphalerite,chalcopyrite and pyrite.A preliminary study indicates that the Nb-Ta-Rb-W-polymetallic ore bodies might be originated from the differentiation of deep-seated ore-bearing magma.The Liangyuan Nb-Ta-Rb-W-polymetallic deposit is characteristic of stable-grade, large scale and complex ore-forming elements with a Nb-Ta-Rb-W-Mo-Sn-Bi assemblage,enriched in Be、REE、Ag.The discovery of Liangyuan deposit is not only a breakthrough of prospecting in the eastern Nanling region,but also an important guide in Nb-Ta-Rb-W-polymetallic ore prospecting work in the whole Nanling and even South China.