| 西藏南羌塘侏罗系色哇组构造变形特征及其构造意义 |
| |
| 引用本文： | 崔玉良,王根厚,郎欣欣,李 典.西藏南羌塘侏罗系色哇组构造变形特征及其构造意义[J].地质科学,2016,0(3):748-762. |
| |
| 作者姓名： | 崔玉良 王根厚 郎欣欣 李 典 |
| |
| 作者单位： | 1. 北京探矿工程研究所 北京 100083；;
2. 中国地质大学（北京）地球科学与资源学院 北京 100083；;
3. 内蒙古自治区第十地质矿产勘查开发院 内蒙古赤峰 024000 |
| |
| 摘 要： | 班公湖—怒江洋的演化一直以来备受关注， 对于其俯冲极性有不同的认识， 前人大多从岩石学、 地球化学等方面的证据去探讨， 而缺乏构造变形的相关研究。本文以构造解析理论为指导， 通过野外大比例尺填图、 构造实测剖面等工作对研究区色哇组的构造样式、 变形期次等进行了研究。综合研究表明， 西藏热那错地区和荣玛地区侏罗系色哇组地层均发育紧闭的三级复式褶皱以及后期叠加的平缓—开阔褶皱。早期褶皱的褶皱轴近东西向展布， 板劈理近东西走向， 是南北向挤压作用的产物。在热那错地区早白垩世美日切错组火山岩角度不整合于已变形的侏罗系色哇组之上， 且色哇组紧闭褶皱的构造样式未在美日切错组火山岩中发育， 推断色哇组紧闭褶皱发生在早白垩世之前。结合研究区大地构造背景， 推断研究区内侏罗系色哇组地层的早期紧闭的三级复式褶皱是班公湖—怒江洋向北俯冲的产物， 而后期叠加的平缓—开阔褶皱可能与羌南地块和拉萨地块的碰撞有关。
|
| 关 键 词： | 南羌塘 班公湖—怒江 侏罗纪地层 复式褶皱 |
| 收稿时间： | 2015-05-27 |
| 修稿时间： | 2015-05-27; |
Structural deformation features of Jurassic Sewa Formation in the southern Qiangtang terrane of Tibet and its tectonic significance |
| |
| Cui Yuliang,Wang Genhou,Lang Xinxin,Li Dian.Structural deformation features of Jurassic Sewa Formation in the southern Qiangtang terrane of Tibet and its tectonic significance[J].Chinese Journal of Geology,2016,0(3):748-762. |
| |
| Authors: | Cui Yuliang Wang Genhou Lang Xinxin Li Dian |
| |
| Institution: | 1. Beijing Institute of Exploration Engineering, Beijing 100083;
2. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083；;3. Inner Mongolia No.10 Institute of Geology and Mineral Exploration and Development， Chifeng， Inner Mongolia 024005 |
| |
| Abstract: | The evolution of the Bangong Co—Nujiang ocean has attracted much more attention all the time. There are many different opinions about its subduction polarity， and most of the predecessors discussed it from petrology， geochemistry and other aspects， while lack of the researches of tectonic deformation. In this paper， guided by the structural analysis theory， the works such as field mapping at a large scale and tectonic measured section are done to study the structural style and deformation phases of the Sewa Formation in the research area. Comprehensive studies showed that the Jurassic Sewa Formation of the two areas both develops tight three—level complex fold and superimposed gentle—open fold in late period. The earlier fold axis and slaty cleavage are nearly E—W trending， which is product of S—N trending compression. In Renacuo region， there is angular unconformity between the Early Cretaceous volcanic rock of Meiriqiecuo Formation and Jurassic Sewa Formation which has deformed， and tight fold tectonic style of Sewa Formation didn’t form in volcanic rock of Meiriqiecuo Formation， which can infer tight fold formed before the Early Cretaceous. Combined with tectonic background in the study area， we can infer that early tight three—level complex fold of Jurassic Sewa Formation is the product of northward subduction of Bangong Co—Nujiang ocean in the study area， and the superimposed gentle—open fold at late stage is related to the collision between Southern Qiangtang block and Lhasa block. |
| |
| Keywords: | Southern Qiangtang terrane Bangong Co—Nujiang Jurassic stratum Complex fold |
|
| 点击此处可从《地质科学》浏览原始摘要信息 |
| 点击此处可从《地质科学》下载免费的PDF全文 |
