CPD Climate of the Past Discussions CPD Clim. Past Discuss. 1814-9359 Göttingen, Germany 10.5194/cp-2016-34 Late Pleistocene to Holocene climate and limnological changes at Lake Karakul (Pamir Mountains, Tajikistan) Heinecke Liv https://orcid.org/0000-0003-3836-8460 1 2 Mischke Steffen https://orcid.org/0000-0003-3821-8497 3 Adler Karsten 2 Barth Anja 4 Biskaborn Boris K. https://orcid.org/0000-0003-2378-0348 1 Plessen Birgit 5 Nitze Ingmar https://orcid.org/0000-0002-1165-6852 1 Kuhn Gerhard https://orcid.org/0000-0001-6069-7485 6 Rajabov Ilhomjon 7 Herzschuh Ulrike 1 2 Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A43, 14473 Potsdam, Germany Institute of Earth and Environmental Science, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany Faculty of Earth Sciences, University of Iceland, Sturlugata 7, Askja, 101 Reykjavík, Iceland Institute of Geological Sciences, Free University of Berlin, Malteserstr. 74-100; 12249 Berlin, Germany Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Sektion 5.2, Telegrafenberg C327, 14473 Potsdam, Germany Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, 27568 Bremerhaven, Germany Pilot Program for Climate Resilience Secretariat, Shevchenko Street 47, Dushanbe, Tajikistan Deutsche Forschungsgemeinschaft GRK 1364 Deutsche Forschungsgemeinschaft 730/15-1 07 04 2016 2016 1 30 Copyright: © 2016 Liv Heinecke et al. 2016 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://cp.copernicus.org/preprints/cp-2016-34/ The full text article is available as a PDF file from https://cp.copernicus.org/preprints/cp-2016-34/cp-2016-34.pdf

Lake Karakul, located in the eastern Pamir Mountains, Tajikistan, is today dominated by the Westerlies. It is a matter of debate whether the Indian Monsoon influenced the region in the past. We analysed an 11.25 m sediment core covering the last 29,000 years to assess and separate lake-internal and lake-external processes, and to infer changes in the predominant atmospheric circulation. Among the parameters indicating lake-external processes, high values in grain-size end-member (EM) 3 (wide grain-size distribution, marking fluvial input) and Sr/Rb and Zr/Rb ratios (coinciding with coarse grain sizes, implying increased physical weathering) are interpreted as a strong monsoonal impact. High values in EM1, EM2 (peaking at small grain sizes reflecting Westerlies-derived dust) and TiO<sub>2</sub> (terrigenous input) are assumed to reflect a strong influence of Westerlies. High input of far-transported dust from the pre-Last Glacial Maximum (LGM) to the late glacial reflects the Westerlies influence, while peaks in fluvial input suggest monsoonal influence. The early to early-mid Holocene is characterised by coarse mean grain sizes, increased physical weathering and constantly high fluvial input indicating a strengthened Indian Monsoon that reached further north into the Karakul region. A steady increase in terrigenous dust, decrease in fluvial input and physical weathering from 6.7 cal kyr BP onwards signals that Westerlies became the predominant atmospheric circulation and brought an arid climate to the region. Proxies for productivity (TOC, C/N, TOC<sub><i>Br</i></sub>), redox potential (Fe/Mn) and changes in the endogenic carbonate precipitation (TIC) indicate lake-internal changes. Low productivity characterised the lake from the late Pleistocene until 6.7 cal kyr BP and rapidly increased afterwards. The lake level remained low until the LGM, but water depth increased during the late glacial, reaching a high-stand during the early Holocene. Subsequently, the water level decreased until its present state. Today the lake system is mainly climatically controlled but the depositional regime is also driven by lake-internal limnogeological processes.