Residual electron spin resonance signals of quartz from the 2018 Baige dammed lake in Tibet: Implications for the identification of sediment layers caused by megafloods

Residual doses may cause overestimation of electron spin resonance (ESR) ages for fluvial sediments. However, ESR residual in outburst megaflood sediments have rarely been evaluated. The Jinsha River, situated the southeastern Tibetan Plateau, is characterized by active faults, narrowed canyons, and dammed lakes. Consequently, river a rare opportunity reconstruction study flood events from paleo-dammed lake. After destruction Baige lake upper River 2018, megafloods formed thick diluvium that was deposited broad valley land along lower River. Based on detailed field investigation laboratory studies, preliminary hydraulics estimates quartz signals indicate following. 1) Among multiple centers, Al, E 1 ʹ, Ti-H, Ti-Li centers could be measured. Ti-H center had lowest dose would provide relatively accurate sediment. 2) Al commonly used dating overestimates 283 ± 42 ka ∼ 462 63 1,010 88 1,400 219 ka, respectively, present 3) diverse given same signal caused various precursors sediments, which are mainly sourced landslide dams terraces slope river. Results demonstrated apparent observed sediment Plateau counterfeit, providing an age much older than its real age. This interpreted to mean channel makes reaches appear lake-like, with deposits having large non-negligible without enough exposure adequate sunlight, despite good stratification sorting characteristics similar those fluvio-lacustrine Thus, abrupt reversal geochronological framework sedimentary profile diluvial or layer absence other inducements.