Glaciers on the Tibetan Plateau(TP) are an important freshwater resource for majorities of populations in Asian. Therefore, it is important to understand past variations in glacier activity on the TP to assess their possible response to ongoing climatic warming. Buruo Co(34°20'~34°28'N, 85°42'~85°49'E, 5170 m a.s.l.) is situated between the the Buruogangri Mountain and Zangsegangri Mountain in the "cold and dry core" of the TP. Buruo Co is a closed proglacial mountain lake with a current surface area of 87.5 km² and catchment area of 550.5 km². The maximum water depth exceeds 100 m. There are many glacier tongues near the lake shoreline and the lake is mainly fed by water from melting snow and glacier ice. Thus, the sediment in Buruo Co is very sensitive to the glacier activity.
A 435 cm long core of Buruo Co(BRLC13-1) was obtained by piston corer, which was used for AMS¹⁴C dating and analysis of climate proxies including grain size, total organic carbon, total inorganic carbon(TIC), particle shapes of Quartz grains and the geochemical element content. Besides, a 65 cm long core(BRGC13-5) was obtained by gravity corer and used for ²¹⁰Pb and ¹³⁷Cs dating. Based on the CRS model, the age at 1 cm depth was -56 a B. P. while at the same depth the radiocarbon age is 3800 a B. P., indicating a carbon reservoir age of 3856 years. The age-depth frame was established by baysian model using ²¹⁰Pb and ¹³⁷Cs measurement and AMS¹⁴C data and the basal age of the BRLC13-1 is estimated to be 5216 cal.ka B. P. In this study, we analyzed the high resolution record and reconstructed the history of glacial activity since 5.2 cal.ka B. P. in Buruo Co catchment. We suppose that the increase in fine franction of sidements indicate the glacier advancce, and the TIC reflect the changes in lake level. The result shows that the retreating glaciers released large amounts of freshwater during 5.2~4.0 cal.ka B. P. During 4.0~1.3 cal.ka B. P., the Westerlies were gradually enhanced and the climate became colder and drier, in response, the glaciers advanced. Subsequently, during 1.3~0 cal.ka B. P., under relatively cold conditions, a large volume of glacial ice was maintained. Besides, according to the changes in fine franction of sediments, 4 episodes of glacial advance at Buruo Co catchment are detected:at 3.6~3.4 cal.ka B. P., 3.2~2.3 cal.ka B. P., 1.9~1.7 cal.ka B. P. and 0.4~0.1 cal.ka B. P. Which corresponds to Bond events in the North Atlantic and these cold events in Buruo Co were influenced by climatic oscillations in the North Atlantic, via the Westerlies. We also suppose that the summer solar insolation, solar activity and the migrations of the Intertropical Convergence Zone influence the climate on the north of TP.