Pollen and diatom records of Lake Big Yarovoe in Kulunda, southern West Siberia, Russia, covering 4 ka

The Kulunda depression is an extensive accumulative lowland in the southeastern part of the West Siberian plane and is located at an altitude of 100-140 m a.s.l. and has numerous salty lakes. Kulunda is situated in the Eurasian steppe zone with a prevalence of grass communities.

Lake Big Yarovoe (drilling place 52° 51.156' N, 78°37.601'E; 79 m a.s.l.) is the deepest closed lake in the western part of the Kulunda depression in the Ob'-Irtysh interfluve (Altai region, southernWest Siberia). The lake has an area of 66.7 km2 with a maximum water depth of 7.4 m and an average depth of 4.4 m. Intense evaporation and low precipitation in the region have led to a high degree of water salinisation. The water of Lake Big Yarovoe is a brine with mineralisation of 135-172 g per litre.

In 2008, a 404 cm long sediment core (2008-3) was recovered from 8 m depth in the southern part of Lake Big Yarovoe. It consists mostly of striated black, grey and greenish-grey silts. The poor organic content of Lake Big Yarovoe sediments posed a problem for radiocarbon dating, but the problem was solved with a geomagnetic approach. A record of geomagnetic inclinations from the studied core was compared with Holocene records of inclinations from Lake Biwa, Japan. The age model of Lake Biwa is based on two widespread tephra layers: Kawagodaira (3.15 ka BP) and Kikai-Akahoya (7.25 ka BP) (Ali et al., 1999). To produce an adequate age-depth model for Lake Big Yarovoe, we transferred the ages of the extremes that the two geomagnetic curves have in common from the Lake Biwa age model to the Lake Big Yarovoe record. For more detailed information see Rudaya et al., 2012.