Lipid Biomarkers of Bottom Sediments in Gusinoe Lake (Lake Baikal Basin) as Indicators for Lake Sedimentogenesis Paleoreconstruction

摘要

Small lakes, being less stable systems as compared to large lakes, are sensitive to climate variations and are characterized by high sedimentation rates, and thus, they represent important archives of paleoenvironmental information. Lipid biomarkers in bottom sediments provide data on the environmental conditions in and around lakes and can be used as additional indirect indicators for paleoreconstruction of lake sedimentogenesis. The distribution of lipid biomarkers in sediments of Gusinoe Lake was determined for the first time using gas chromatography (GC) and GC-mass-spectrometry. The main lipid biomarkers of the terrestrial (long-chain fatty acids, alcohols, dicarboxylic acids, and beta-sitosterol) and aquatic (short-chain fatty acids, hydroxy acids, etc.) origins of organic matter were revealed. The distribution of the carbon preference index (CPI) in the core of bottom sediments of Gusinoe Lake testifies to the transition from cold and dry (lower core layers) to warm and humid climatic conditions.