西藏冈底斯岩带中段南缘韧性剪切带特征

详细信息

Basic characteristics of the ductile zone on the southern margin of the central sector of the Gangdise rock belt, Tibet

Institute of Geological Survey, Jiangxi Bureau of Geology and Mineral Exploration and Development,Nancang,Jiangxi 330201,China

摘要: １∶２０万曲水幅区域地质调查中发现了一条东西向巨大韧性剪切带，据几何形态和显微组构特征，该剪切带属于正剪切带性质，是在始新世晚期（４０～４２Ｍａ）印度板块与欧亚大陆发生碰撞时的产物。区内在构造—岩浆作用下，造成地壳不同层次拆离滑脱及韧性剪切带的形成，解释了地壳增厚、构造变形弱及地球物理多层结构不明显的特征。
Abstract: An E W trending gigantic ductile shear zone was found during regional geological survey of the 1∶200 000 Qüxü Sheet. According to its geometric form and microfabrics, this shear zone has the nature of a normal shear zone. It is the product of collision of the Indian plate and Eurasian continent during the late Eocene （40～42 Ma B.P.）. The tectono magmatism in the study area resulted in the décollement in different levels of the earth’s crust and formation of a ductile shear zone. This gives relatively reasonable explanations of crustal thickening, tectonic deformation and geophysically indistinct multi layered structure.
- Gangdise rock belt /
- ductile shear zone /
- Qüxü,Tibet