Early to mid-Holocene lake high-stand sediments at Lake Donggi Cona, northeastern Tibetan Plateau, China

Lake high-stand sediments are found in three onshore terraces at Lake Donggi Cona, northeastern Tibetan Plateau, and reveal characteristics of hydrological changes on lake shorelines triggered by climate change, geomorphological processes, and neo-tectonic movements. The terraces consist of fluvial-alluvial to littoral-lacustrine facies. End-member modeling of grain-size distributions allowed quantification of sediment transport processes and relative lake levels during times of deposition. Radiocarbon dating revealed higher than modern lake levels during the early and mid Holocene. Lake levels follow the trend of Asian monsoon dynamics, and are modified by local non-climatic drivers. Site-specific impacts explain fluctuations during the initial lake-level rise similar to 11 cal ka BP. Maximum lake extension reached similar to 9.2 cal ka BP, at similar to 16.5 m above present lake level (a.p.l.l.). Littoral and lacustrine sediment deposition paused during a phase of fluvial activity and post-depositional cryoturbations at similar to 8.5 cal ka BP, when the lake level fell to similar to 8 m a.p.l.l. After a second maximum at similar to 7.5 cal ka BP, lake level declined slightly at similar to 6.8 cal ka BP, probably due to a non-climatic pulse that caused lake opening. The level remained high until a transition towards drier conditions similar to 4.7 cal ka BP. Though discontinuous, high-stand sediments provide a unique, high-resolution archive. (C) 2013 University of Washington. Published by Elsevier Inc. All rights reserved.