Climatic Changes Reflected in the Distribution of Organic Matter and Major Elements in the Holocene Lake Baikal Bottom Sediments of Selenga Delta Area

The sediment cores from Selenga delta area reveal two types of stratigraphic section formed under different hydrological conditions but both responsive to climatic changes. The vertical distributions of organic and certain inorganic compounds are in close agreement with the Holocene pattern of changes in temperature and humidity, reproduced earlier from palynological data. Inorganic geochemistry reflects the removal of weathering products from the catchment soils. The data on the organic matter content permits a judgement on relative importance of lacustrine and terrestrial biomass in sediment formation of different periods. Climatic reconstructions based on the organic matter content differ somewhat from palynological history of climate for the same period, because with the huge biomass developed, the lacustrine system becomes less sensitive to external organic supply.