西藏班公湖—怒江成矿带与邻区铟矿化带的发现及意义

Discovery and Significance of Indium Mineralization Belt in Bangong Lake——Nujiang River Metallogenic Belt and Adjacent Regions in Xizang(Tibet)

铟是稀散金属元素,在地壳中的含量为0.1×10-6。我国铟的储量居世界第一,广西大厂矿田是我国重要的产铟基地。本文在大量的野外地质调查与室内分析测试与扫描电镜观察等工作的基础上,首次查明了西藏班公湖—怒江成矿带及邻区的铟含量与赋存状态。在铟含量较高的13个矿床(点)中,5个矿床(点)样品铟的平均品位达到伴生工业品位的要求。铟含量高的地质体呈带状展布,为我国一个新的铟矿化带,铟矿物种类为羟铟石、自然铟两种。铟含量较高的样品全部位于矽卡岩型矿床中。班公湖—怒江成矿带铟的矿化时代应为班公湖—怒江洋向南(即冈底斯地块)俯冲使之闭合后碰撞阶段所形成。当雄县拉屋多金属矿床正在开采,其铟含量平均为45.44×10-6,最高为166×10-6,需加强铟资源的评价,提高其资源的综合利用价值。

Indium is one kind of dissipated metallic elements,and its content is 0.1×10^-6 in the earth’s crust.The reserves of Indium in China ranks 1st in the world.The Dachang orefield in Guangxi is the biggest production base of indium in our country.Based on many geological surveys in the field,indoor analytical tests,observing with scanning electron microscope and so on,writers finds out the content and occurrence of indium element in the Bangong Lake—Nujiang River Metallogenic belt and adjacent area.Among of the 13 deposits in which the content of indium is higher,there are 5 deposits in which the average content of the samples reaches the requirement of industrial grade.The area where the content of indium is high usually shows belt-like,and is a new metallogenic belt of indium mineralization in China.The kinds of indium minerals are dzhalindite and native indium.The high content part situates in skarn deposit.The mineralized age of indium in the Bangong Lake—Nujiang River Metallogenic belt should be the encounter stage after the Bangong Lake—Nujiang River Metallogenic dived southward （the Gangdese plate） and made itself close.The Lawu polymetallic deposit,Dangxiong County,is exploiting now.Its average content of indium in ores is 45.44×10^-6,and the highest content is 166×10^-6.So the evaluation of indium resource need to be strengthened in order to improve comprehensive utilization of this resource.