Characteristics and Formation Mechanism of Giant Long-Runout Landslide: A Case Study of the Gamisi Ancient Landslide in the Upper Minjiang River, China

作     者：GUO Changbao WU Ruian ZHANG Yongshuang REN Sanshao YANG Zhihua LI Xue 

作者机构：Institute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China Key Laboratory of Active Tectonics and Crustal Stability AssessmentBeijing 100081China Tianjin CenterChina Geological SurveyTianjin 300170China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2019年第93卷第4期

页      面：1113-1124页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 

基　　金：supported by the National Natural Science Foundation of China(41731287,41877279) China Geological Survey Project(DD20160271) 

主　　题：Tibetan plateau ancient landslide Gamisi long runout formation mechanism 

摘      要：The upper reaches of the Minjiang River are in the eastern margin of the Tibetan Plateau,where active faults are well developed and earthquakes frequently *** climate change and the extremely complex geomechanical properties of rock and soil have resulted in a number of *** on the analysis of remote sensing interpretations,geological field surveys,geophysical prospecting and geological dating results,this paper discusses the developmental characteristics of the Gamisi ancient landslide in Songpan County,Sichuan Province,and investigates its geological age and formation *** study finds that the Gamisi ancient landslide is in the periglacial region of the Minshan Mountain and formed approximately 25 ka *** landslide initiation zone has a collapse and slide zone of approximately 22.65×106–31.7×106 m3 and shows a maximum sliding distance of approximately 1.42 km,with an elevation difference of approximately 310 m between the back wall of the landslide and the leading edge of the accumulation *** landslide movement was characterized by a high speed and long *** the sliding process,the landslide body eroded and dammed the ancient Minjiang River *** ancient river channel was buried 30-60 m below the surface of the landslide accumulation *** prospecting and drilling observations revealed that the ancient riverbed was approximately 80-100 m *** the dam broke,the Minjiang River was migrated to the current channel at the leading edge of the *** Gamisi ancient landslide was greatly affected by the regional crustal uplift,topography,geomorphology and paleoclimatic *** combined action of periglacial karstification and climate change caused the limestone at the rear edge of the landslide fractured,thus providing a lithological foundation for landslide *** tectonic activity along the Minjiang Fault,which runs through the middle and trailing parts of the Gamisi ancient l