Our 12.81 m long record from Lake Ximencuo provides insight into the Lateglacial and Holocene evolution of the lake and the Nianbaoyeze glacier in its catchment, and the regional climate history since ∼19 kyr. Lake Ximencuo was a permanent deep lake throughout its history. In contrast to numerous lakes on the Tibetan Plateau which experienced shallow lake levels or even desiccation during the Lateglacial, Lake Ximencuo was fed by large quantities of meltwater in the Lateglacial. The existence of glaciated upper catchment areas is apparently a prerequisite for lakes on the Tibetan Plateau which maintained relatively high water levels during the generally cold and dry periods following the global LGM (∼21 kyr). A minor re-advance of the Nianbaoyeze glacier was recorded coeval with the Greenland Stadial 2a (∼16.4 and 14.5 kyr), followed by rapid warming apparently synchronous with the Greenland Interstadial 1. Warmest conditions were recorded at Lake Ximencuo during the early Holocene which was punctured by a remarkable pulse of climate deterioration around 8.3 kyr. This spell represents probably the 8.2 kyr event of the North Atlantic region, suggesting that it had a significant impact on the Tibetan Plateau. Colder conditions of longer duration occurred from 4.7 to 3.7 kyr, apparently in phase with numerous records signalling colder and drier conditions on the Tibetan Plateau. Two minor spells of colder conditions and probably catchment erosion were recorded in the late Holocene between 2.0 and 1.4 kyr and between 0.5 and 0.1 kyr with the latter representing the Little Ice Age. It is unclear, whether human activities may have accelerated or even solely triggered the late Holocene erosion events.
Bibliographical noteFunding Information:
We are indebted to Huaming Shang, Yanbin Lei and Xiaolong Liu for help during fieldwork, and Zuqin Deng, Juan Kuang, Yixin Hu and Jun Chen for help with core cutting and sampling in the laboratory of Lanzhou University. Zhaodong Feng supported the radiocarbon dating. Lewis Owen, Frank Lehmkuhl and an anonymous reviewer provided many constructive and thoughtful comments which helped to improve the manuscript. In addition, we wish to thank the journal's editor, Xiaoping Yang, for his helpful instructions. The manuscript was written during a stay of S.M. at the Limnological Research Center (LRC) of the University of Minnesota (USA) while he was in receipt of a research fellowship of the German Research Foundation, and S.M. would like to thank Emi Ito and other members of the LRC for their kind hospitality during his visit. Funding was provided by the Deutsche Forschungsgemeinschaft (grant Mi 730/1-1 to SM), the National Natural Science Foundation of China (NSFC, grant 40773064 to CZ) and the National Science Foundation (USA, grant ESH 0402509-2004 to Zhaodong Feng).
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