Chronology analysis of huge landslide based on ESR dating materials on sliding face in carbonate areas of south eastern Tibet

Determining occurrence age is key to chronology analysis of huge landslides. However, in carbonated bedrock areas, it is difficult to carry out geochronological surveys of landslide evolution due to lack of suitable dating materials and methods. In carbonated bedrock areas, the cosmic nuclides 36Cl and 14C dating methods have been used for obtaining the exposed age of bedrock. But intense weathering, erosion and dissolution make it difficult to obtain an accurate total amount of cosmogenic nuclide accumulation, resulting in the dating results being affected greatly by weathering, erosion and dissolution of carbonate rock. Therefore, it is necessary to find new dating materials or methods for determining the occurrence age of landslide in carbonate bedrock areas with little quaternary sediments. In this study, a huge landslide developed in the carbonate bedrock area of south eastern Tibet is introduced briefly, which is named the Qiaojia landslide and blocked the Jinsha River. A thin layer including three obvious recrystallized carbonate sub-layers was formed in the sliding zone, indicating different sliding events. Three recrystallized carbonate samples were then collected for ESR dating research to obtain the age information of the Qiaojia landslide: one occurred 79 ± 8 ka years ago, and the other occurred 60 ± 10 ka years ago, and the third occurred 25 ± 2 ka years ago, which are in general agreement with other studies in the surrounding of the study area. It suggests that recrystallized carbonate on sliding face is suitable for chronologically identifying landslide activity by using ESR method in the carbonate area, especially in the areas with little or no quaternary sediments.