北喜马拉雅错那洞穹隆:片麻岩穹隆新成员与穹隆控矿新命题

发布时间：2018-05-23 08:35

本文选题：片麻岩穹隆 + 花岗片麻岩　；参考：《地球学报》2017年05期

【摘要】：错那洞片麻岩穹隆位于特提斯喜马拉雅南侧,靠近藏南拆离系,是北喜马拉雅片麻岩穹隆带(NHGD)中最新发现的新成员。本文在详实的野外地质调查基础上,首次全面介绍了错那洞片麻岩穹隆的结构组成,同时进行了片麻岩的年代学研究。结果表明,错那洞片麻岩穹隆由核-幔-边三部分组成,核部由花岗片麻岩及淡色花岗岩组成,并可见大量伟晶岩脉穿插;幔部为一套强变质变形的二云母片岩,从内至外具有夕线石+石榴石→蓝晶石+石榴石→十字石+石榴石→石榴石+十字石+堇青石→堇青石+石榴石的变质分带特征;边部主要为浅变质沉积岩系,可见较多因穹隆隆升而形成的A型褶皱。花岗片麻岩LA-ICP-MS锆石U-Pb年龄为(499.7±3.4)Ma(MSWD=0.025),与NHGD其它穹隆核部片麻岩时代基本一致,均为泛非—早古生代造山活动的产物。在本次野外地质调查过程中,在错那洞片麻岩穹隆中发现了矽卡岩型钨锡铍工业矿体以及铜金矿化体,同时在伟晶岩中还存在着大量的绿柱石等宝石矿产,这样的成矿作用与矿化组合在NHGD中尚属首次发现,基于此本文提出了北喜马拉雅片麻岩穹隆控矿新命题。
[Abstract]:The Dinaodong gneiss dome, located in the south of Tethys Himalaya, is a newly discovered member of the Northern Himalayan Gneiss Dome (NHGD). On the basis of detailed field geological survey, the structural composition of the dome of the gneiss in Dina cave is introduced for the first time, and the geochronology of the gneiss is also studied. The results show that the dome is composed of three parts: core, mantle and edge, the core is composed of granitic gneiss and pale granite, and a large number of pegmatite veins can be seen in the dome, and the mantle is a set of strongly metamorphic dimica schist. It has the metamorphic zonation characteristics from the inside to the outside of the sillimanite garnet, cordierite, and cordierite garnet. It can be seen that more A-type folds formed by dome uplift. The LA-ICP-MS zircon U-Pb age of the granitic gneiss is 499.7 卤3.4 Ma-MSWDU 0.025, which is basically consistent with the gneiss age of the other dome of NHGD, and is the product of the Pan-African early Paleozoic orogenic activity. In the course of this field geological survey, skarn type tungsten, tin, beryllium industrial ore bodies and copper-gold mineralization bodies were found in the dome of the gneiss in Dhonaodong, and there are also a large number of gemstone minerals such as Beryl in pegmatite. This combination of mineralization and mineralization is first discovered in NHGD. Based on this, a new proposition of controlling ore deposits in the dome of the northern Himalayan gneiss is proposed.
【作者单位】：中国地质调查局成都地质调查中心;
【基金】：国家重点研发计划深地资源开采项目(编号:2016YFC0600308) 中国地质调查局地质调查项目(编号:DD20160015)联合资助~~
【分类号】：P588.345;P612

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