青海东昆仑沉积型锰矿构造背景与成矿规律  

Tectonic Setting and Metallogenic Regualtion of Sedimentary Manganese Deposits of East Kunlun, Qinghai Province

作　　者：刘永乐 张爱奎 张建平 李文[2,3] 李文君[2] 董志国[2] 朱明田 张连昌[2] Liu Yongle;Zhang Aikui;Zhang Jianping;Li Wen;Li Wenjun;Dong Zhiguo;Zhu Mingtian;Zhang Lianchang(Third Geological Exploration Institute of Qinghai Province,Xining 810029,China;Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]青海省第三地质勘查院,青海西宁810029 [2]中国科学院矿产资源研究重点实验室,中国科学院地质与地球物理研究所,北京200029 [3]中国地质大学地球科学与资源学院,北京100083

出　　处：《地球科学》2024年第12期4278-4302,共25页Earth Science

基　　金：国家重点研发计划项目(No.2022YFC2903502);青地三勘(No.2022-14);青海省自然资源厅(No.2021-114)。

摘　　要：东昆仑造山带位于青藏高原东北部,经历了早期原特提斯洋构造演化,形成了一系列海相沉积型锰矿床.但对于东昆仑地区原特提斯洋演化的具体细节仍存在伸展与俯冲、活动大陆边缘与被动大陆边缘、岛弧与弧后盆地等不同的认识;有关大洋封闭的时间也存在中-晚奥陶世和早志留世的争议.本文通过东昆仑地区海相沉积型锰矿容矿围岩砂岩、粉砂岩和硅质岩的岩相学观察、主量和微量元素地球化学测试,并与形成于不同构造环境的砂岩与硅质岩进行对比分析,结果表明形成于中元古代的洪水河铁锰矿和浪木日锰矿,以及形成于奥陶纪-早志留世的三通沟北锰矿具有活动大陆边缘的地球化学特征,而形成于新元古代三通沟VI-VII锰矿带表现为被动大陆边缘的构造属性.综合研究认为东昆仑中带和南带从中元古代蓟县系狼牙山组到新元古代万宝沟群经历了原特提斯洋的活动大陆边缘到被动大陆边缘的演化过程,而奥陶纪-早志留世纳赤台群形成于原特提斯洋俯冲-岛弧增生-弧后盆地阶段.The East Kunlun orogenic belt is located in the northeast of the Qinghai-Tibet Plateau. It experienced the early tectonic evolution of the Proto-Tethys Ocean and formed a series of marine sedimentary manganese deposits . However, there are still different understandings on the specific details of the evolution of the Proto-Tethys Ocean in East Kunlun, such as expansion and subduction, active and passive continental margins, island arc and back-arc basin. There are also controversies regarding the timing of ocean closure during the Middle-Late Ordovician or Early Silurian periods. Based on the geological and geochemical research of sandstone and siliceous rock in marine sedimentary manganese deposits in East Kunlun, it was indicated that Hongshuihe ferromanganese and Langmuri manganese deposits formed in the Mesoproterozoic, as well as Ordovician-Early Silurian Santonggou north manganese deposit, show geochemical characteristics of active continental margin, but Santonggou Ⅵ-Ⅶ manganese ore belt formed in the Neoproterozoic shows the tectonic attribute of passive continental margins. Comprehensive research indicates that the minddle and south Kunlun belts in Proto-Tethys tectonic domain has undergone an evolution processes from Mesoproterozoic active continental margin to Neoproterozoic passive continental margin, and Ordovician-Early Silurian Nachitai Group was formed in the stage of island arc accretion or back-arc basin in the Proto-Tethys Ocean.

关 键 词：沉积锰矿 构造背景 成矿规律 原特提斯洋 东昆仑 矿床 

分 类 号：P624[天文地球—地质矿产勘探]