藏南地区错那洞钨锡多金属矿床地质特征及成因

前人尚未关注特提斯喜马拉雅铅锌金锑成矿带钨锡成矿问题.错那洞钨锡多金属矿床位于特提斯喜马拉雅东段，产于新发现的错那洞大型片麻岩穹隆构造之中.错那洞钨锡多金属矿床主要富集钨、锡、铍，伴生铜、铅、锌、铋、钼等，其矿化类型主要为矽卡岩型；此外，铍的矿化类型还有伟晶岩型.主要矿石矿物为白钨矿、锡石和硅铍石，含有少量的黄铜矿、方铅矿、闪锌矿、辉铋矿、辉钼矿等，翠砷铜铀矿、晶质铀矿和钍石的发现表明错那洞地区具铀矿成矿潜力.研究结果表明，错那洞钨锡多金属矿床可达到大型-超大型规模.较低的Zr含量、Zr/Hf和Nb/Ta比值表明错那洞大型片麻岩穹隆核部淡色花岗岩为高分异花岗岩；花岗岩具有富钛铁矿、贫磁铁矿特征，Fe₂O₃/FeO < 0.5，锆石Ce/Ce*平均值约为23，暗示错那洞淡色花岗岩为还原性花岗岩.具还原性的高分异花岗岩是错那洞钨锡多金属矿床形成的必要条件，而片麻岩穹隆构造是其空间分布的控制因素，由此认为错那洞钨锡多金属矿受片麻岩穹隆构造和淡色花岗岩的双重控制. 

Geology and Preliminary Mineral Genesis of the Cuonadong W-Sn Polymetallic Deposit,Southern Tibet,China

Researchers have not paid attention to the tungsten-tin mineralization of the Tethys Himalayan lead-zinc-gold-metallogenic belt.The Cuonadong W-Sn polymetallic deposit is located in a newly recognized giant gneiss dome, eastern Tethys Himalaya.The deposit is rich in W, Sn and Be, accompanied by Cu, Pb, Zn, Bi and Mo, of which mineralization type is skarn-type. Besides, the mineralization of beryllium contains pegmatite type.Main ore minerals are scheelite, cassiterite and bertrandite, with minor chalcopyrite, galena, sphalerite, bismuthinite and molybdenited.There are also some zeunerite, uraninite and thorite, indicating the uranium mineralization potential.Geological survey shows that the Cuonadong W-Sn polymetallic deposit could be a large-or super large-scale ore deposit.Low concentration of Zr and relatively low ratios of Zr/Hf and Nb/Tb demonstrate that leucogranite within the Cuonadong dome is highly fractional crystallization.Meanwhile, there is absolutely little magnetite but relatively rich in ilmenite with Fe₂O₃/FeO < 0.5 and low Ce/Ce* ratio (average 23) in leucogranite, indicating characteristics of reductive granite.The reductive and highly fractional crystallization granite is a necessary condition for the formation of the tungsten-tin polymetallic deposit, additionally, the gneiss dome controls its spatial distribution.Therefore, the Cuonadong W-Sn polymetallic deposit is both controlled by dome structure and leucogranite.