HIGH-RESOLUTION POLLEN RECORDS FROM THE BOTTOM SEDIMENTS OF LAKE BAIKAL

Within the framework of ongoing EU Project CONTINENT, clayey sediments from 3 box cores and 2 piston cores were searched by pollen analysis to reconstruct climate signals during the Last Interglacial and Late Glacial and Holocene.

Late Glacial and Holocene pollen successions were taken from 3 stations: Vidrino Shoulder, Southern Basin (cores CON01-605-5 and CON01-605-3), Posolskoye High, Central Basin (CON01-606-3) and Continent Ridge, Northern Basin (CON01-603-5). All the pollen diagrams were visually subdivided into local pollen assemblage zones (L PAZ), which reflect vegetation changes in the regions of the  Khamar-Daban Mts., the Selenga Delta, and the Barguzin Mts., respectively.

The general pattern of the vegetational changes in all the profiles is very similar and includes Late Glacial steppe-tundra plant communities with Betula nana, Salix, Cyperaceae, Poaceae, Artemisia, Chenopodiaceae, and many others, followed by strong expansion of Alnus fruticosa. The Holocene part of the succession began with an expansion of Betula-Picea-Larix forests accompanied by a strong spread of Pteridium and Abies followed by development of dark taiga communities with Pinus sibirica, P. sylvestris, Picea, and Abies. In the southernmost  station, i.e. Vidrino, P. sibirica and P. sylvestris appeared as early as Betula, Picea and Larix. Later, these communities changed into forest which was more of the light taiga type, pointing to the climate becoming drier. L PAZ’s and AMS ¹⁴C-datings allowed for correlation of the cores and delineation of the Younger Dryas-Holocene transition.

Pollen analysis of piston core CON01-603-2 from Continent Ridge produced an interglacial pollen succession. Subsampling of the core for pollen analysis was performed following the magnetic susceptibility data. This pollen succession differs from the Holocene one from the same site (CON01-603-5) in having higher Abies and lower Larix percentages, which points to higher temperatures and precipitation. Moreover, this succession is covered by a glacial sequence, which spans the entry into glaciation and at least one warm interval of interstadial rank. Assuming no hiatus between the Holocene and the last interglacial this succession has to be considered the equivalent of the Eemian (=Kazantsevo) Interglacial.