北喜马拉雅错那洞穹隆铍铷稀有金属矿床地质特征及找矿方向

Geological characteristics and prospecting direction of Cuonadong Be-Rb rare metal deposit in Cuonadong gneiss dome of North Himalaya

错那洞穹隆是北喜马拉雅片麻岩穹隆带(NHGD)中发现的新成员,穹隆由核-幔-边 3 部分组成。核部由寒武纪花岗质片麻岩组成,幔部由早古生代云母片岩和矽卡岩化大理岩组成,边部由变质沉积岩组成。在穹隆核部侵入有大量淡色花岗岩和伟晶岩脉。通过系统的地表工程控制,在穹隆幔部中新发现了环穹隆展布、层位稳定的矽卡岩带和厚大的铍铷稀有金属工业矿体。通过对错那洞穹隆东部矿带典型矿区的解剖,初步把矿床的类型定为热液型稀有金属矿床,在碳酸盐赋矿层位中形成富铍、铷、钨、锡的矽卡岩型矿床。铍铷稀有金属矿具超大型的资源潜力,钨锡也达大型规模。错那洞铍铷稀有金属矿主要的矿床类型为矽卡岩型。此外,还有伟晶岩型稀有金属矿、锡石硫化物型锡多金属矿。文章研究矿体特征和总结矿床类型,提出了下一步的找矿方向。

The Cuonadong gneiss dome is a newly discovered dome in the North Himalaya Gneiss Domes (NHGD) belt, Studies show that the Cuonadong gneiss dome is composed of three parts, the core is composed of Cambrian granitic gneiss, the mantle part is composed of Early Paleozoic mica schist and skarn marble, and the outer part is mainly composed of metamorphic sedimentary rocks. Leucogranites and a large number of pegmatite veins intruded into the core of the Cuonadong gneiss dome. A stable skarn zone and thick Be-Rb rare metal orebodies were newly found by the sparse exploration engineering surface in the mantle part around the core of the dome . Through the anatomy of a typical mining area in the east of the Cuonadong dome, the type of the deposit was preliminarily identified as a hydrothermal rare metal deposit. Skarn deposits formed in Carbonate formation are rich in Be, Rb, W and Sn. Beryllium and rubidium ore resources are estimated to be of up to superlarge size,and paragenetic W-Sn ore resources are of large scale. The main genetic type of the deposit is skarn type;besides, pegmatite rare meta ore and cassiterite-sulfide polymetallic ore were also found. Based on the study of characteristics of orebody and the summary of deposit types, the authors point out the next prospecting direction.