Modern sedimentary process of Lake Basomtso in the southeastern Tibetan Plateau and its response to climate change

Lacustrine sediment has been regarded as one of the most important archives for inferring information about past climate fluctuations, which presented significant palaeoclimate sequences at different time scales. Various proxies have been investigated to acquire signals of climate changes, which, however, does not always lead to consistent inferences. In order to acquire the information of reliable climate changes from lake sediments, we now intend to investigate the relationship between sedimentary proxies and environment parameters especially the climate changes, to explore how the proxies respond to environment change. Thus, we chose Lake Basomtso from the southeastern Tibetan Plateau as our study area considering the high sedimentation rate and rare human activities. Combined with the chronology based on measurements of 210Pb and 137Cs, grain size, magnetic susceptibility and organic matter content of the modern sediments from both sediment cores and traps were analyzed. The results were subsequently compared with modern meteorological data from Nyingchi Station. The sediment mainly consists of two parts: the aeolian transported materials during the winter time from the south and southwest of the Tibetan Plateau, which showed significant consistence with the regional wind speed; and the fluvial transported materials that influenced by the temperature (melting effect) and precipitation together. The fluctuation of magnetic susceptibility of lake sediment of Lake Basomtso mainly reflects the input of magnetic mineral, which is closely affected by the precipitation related erosion rate. Finally, the variation of total organic carbon, total nitrogen content generally showed a gradual increasing trend of lake primary productivity, which responds closely to the changes of temperature, especially the global warming process. © 2019 by Journal of Lake Sciences.