Preprints
https://doi.org/10.5194/cp-2016-34
https://doi.org/10.5194/cp-2016-34
07 Apr 2016
 | 07 Apr 2016
Status: this preprint was under review for the journal CP but the revision was not accepted.

Late Pleistocene to Holocene climate and limnological changes at Lake Karakul (Pamir Mountains, Tajikistan)

Liv Heinecke, Steffen Mischke, Karsten Adler, Anja Barth, Boris K. Biskaborn, Birgit Plessen, Ingmar Nitze, Gerhard Kuhn, Ilhomjon Rajabov, and Ulrike Herzschuh

Abstract. 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 TiO2 (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, TOCBr), 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.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Liv Heinecke, Steffen Mischke, Karsten Adler, Anja Barth, Boris K. Biskaborn, Birgit Plessen, Ingmar Nitze, Gerhard Kuhn, Ilhomjon Rajabov, and Ulrike Herzschuh
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Liv Heinecke, Steffen Mischke, Karsten Adler, Anja Barth, Boris K. Biskaborn, Birgit Plessen, Ingmar Nitze, Gerhard Kuhn, Ilhomjon Rajabov, and Ulrike Herzschuh

Data sets

XRF-Core scanner data is stored in PANGAEA Heinecke, Liv; Herzschuh, Ulrike http://doi.pangaea.de/10.1594/PANGAEA.842725

Liv Heinecke, Steffen Mischke, Karsten Adler, Anja Barth, Boris K. Biskaborn, Birgit Plessen, Ingmar Nitze, Gerhard Kuhn, Ilhomjon Rajabov, and Ulrike Herzschuh

Viewed

Total article views: 3,350 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
1,890 1,291 169 3,350 282 96 169
  • HTML: 1,890
  • PDF: 1,291
  • XML: 169
  • Total: 3,350
  • Supplement: 282
  • BibTeX: 96
  • EndNote: 169
Views and downloads (calculated since 07 Apr 2016)
Cumulative views and downloads (calculated since 07 Apr 2016)

Cited

Latest update: 06 Dec 2024
Download
Short summary
The climate history of the Pamir Mountains (Tajikistan) during the last ~29 kyr was investigated using sediments from Lake Karakul as environmental archive. The inferred lake level was highest from the Late Glacial to the early Holocene and lake changes were mainly coupled to climate change. We conclude that the joint influence of Westerlies and Indian Monsoon during the early Holocene caused comparatively moist conditions, while dominating Westerlies yielded dry conditions since 6.7 cal kyr BP.