Reconstructions of the ecological conditions of the Holocene in the region of Steppe Altay, using sediment archives of the Lake Yarovoe

• Main Authors: Nazarova, Larisa, Nourgaliev, D., Frolova, Larissa, Palagushkina, Olga, Rudaya, N., Krylov, P., Kosareva, L., Gafiatullina, L., Gilmanova, D.
• Format: Conference Object
• Language: unknown
• Published: 2010
• Subjects: North Atlantic; Tundra
• Online Access: https://epic.awi.de/id/eprint/22540/; https://hdl.handle.net/10013/epic.35215

The Altai Mountains are located in the center of climatologically sensitive region. Here, major polar and subpolarair masses meet, making Altai Mountain region to an ideal place to record shifts in atmospheric circulation. Dueto its position in the center of the Eurasian continent, it is a key region for studying the past variations in theArctic monsoon strength, the Siberian high pressure system, and the Westerlies that bring North Atlantic moistureto the interior of Eurasia. The precipitation in the Altai Mountains is mainly driven by cyclonic activities andmonsoons. Any small change in global atmospheric circulation causes a distinct change in the regional climate, i.e.in temperature and precipitation of this area, and leads to sharp changes of vegetation and landscapes. As a result,there are ecologically contrasting biomes such as mountainous conifer forests, dry steppe and high mountainmeadows and tundra vegetation within relatively short distances, depending on elevation, and slope aspect.Lake Bolshoe Yarovoe (52°56Ž00˝ N and 78°35Ž00˝ E.) is the deepest one among the lakes in Kulundin steppe.It is situated in the lowest place of the Alaty region (79 a.s.l.). The total area of the lake constitute 70 squarekm with the maximal depth averaging at 25 m. Sediments of the lake were investigated with the methodsof mineralogical, lithological, palaeomagnetic analysis and using paleolimnological proxies (pollen, diatoms,cladocera, chironomids). After the correlation of our data with the world data (Lake Biwa, Japan), we found thatthe oldest part of the investigated cores are 4,5 ka old. Preliminary seismographical interpretation of the obtaineddata allows us to suppose a considerable strong influence of neotectonical, palaeogeographical and other factors onthe processes of sedimentation in the lake Bolshoe Jarovoe. Seismoacustical investigations have revealed presenceof the mud vulcanism in the lake, areas that are influenced by thermal waters and elevated gases concentrations.Reconstructions of the ecological ...