Research on Tectonic Features and Dynamics in the Northwestern Yunnan Extensional Region  

作　　者：Han Zhujun,Xu Jie,Guo Shunming,Yang Zhu’en,Xiang Hongfa,and Wu DaningInstitute of Geology,SSB,Beijing 100029,China 

出　　处：《Earthquake Research in China》1995年第2期13-21,共9页中国地震研究（英文版）

摘　　要：The paper discusses the features of active tectonics,seismicity and neotectonic environment in the Northwestern Yunnan extensional region.The intensity of both tectonic activity and seismicity is strong near the south and north boundaries in the areas,but weak in the middle.The distribution of the strongest subsided areas,lacustrine terrace and Quaternary fold is characterized by the diagonal symmetry.Formation of extensional tectonics in the Northwestern Yunnan can be explained by passive model,experiencing the action of compressional force in the N-S direction and shear force in the SW-NE direction,and classified as a special pull-apart tectonics.The direction of the composite force is NNE,which is coincided with the results acquired by the methods of water-compressed rupture and physical modelling.The paper discusses the features of active tectonics,seismicity and neotectonic environment in the Northwestern Yunnan extensional region.The intensity of both tectonic activity and seismicity is strong near the south and north boundaries in the areas,but weak in the middle.The distribution of the strongest subsided areas,lacustrine terrace and Quaternary fold is characterized by the diagonal symmetry.Formation of extensional tectonics in the Northwestern Yunnan can be explained by passive model,experiencing the action of compressional force in the N-S direction and shear force in the SW-NE direction,and classified as a special pull-apart tectonics.The direction of the composite force is NNE,which is coincided with the results acquired by the methods of water-compressed rupture and physical modelling.

关 键 词：NORTHWESTERN Yunnan Active TECTONIC zone SEISMICITY feature Crustal DYNAMICS PULL-APART structure 

分 类 号：P542[天文地球—构造地质学]