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Late Quaternary history of Issyk Kul, Kyrgyzstan, inferred from surface, outcrop, and abyssal core sediments

Lake Issyk Kul is the world’ s second largest mountain lake and occupies a deep basin in the Tien Shan range, Kyrgyzstan. The lake offers a record of continental climate spanning millions of years that is likely unmatched by any other source. An ICDP funded workshop took place in 2011 and revealed that additional scientific investigations comprising seismic and sedimentological studies in the lake basin are necessary to define specific drilling locations and depths for an ICDP full proposal.

The here proposed project will provide missing sedimentological information from the lake basin, as it is requested in the workshop report. The main objectives of this project are to study in more detail the surface sediment distribution in Issyk Kul and Late Quaternary outcrops at its southern shore, which indicate lake level high-stands between ca. 43 and 25 ka. Moreover, the project aims to recover, for the first time, 6-10 m long sediment sequences comprising interglacial (Holocene) and Last glacial sediments from the abyssal part of Issyk Kul at water depths of more than 500 m. The investigation of (bio-)geochemical, mineralogical, and grain-size characteristics and their downcore variations and a correlation of the information with that derived from surface and outcrop sediments will help to examine, if Issyk Kul can provide a continuous high-resolution record of climate change and shifts in atmospheric circulation patterns, in phase relationships of local Alpine glaciers and continental ice sheet advances, and the roles of tectonics and climate change in affecting erosion rates in the catchment. This project seeks to overcome the missing knowledge of sedimentation characteristics and sedimentation rates from the abyssal part of Issyk Kul and to provide information on potential deep drilling sites in the central part of the basin, which is most likely the only site, which contains the entire history of basin back to several Myr ago.

The project is fundamental to re-activate the ICDP Issyk Kul initiative. It will help to form a new team of international scientists, including members of the former initiative, but also new members, and to establish a deep drilling in the lake basin.