Lipid biomarkers in paleoreconstruction of lake sedimentogenesis

Abstract Lakes are important paleoenvironmental archives retaining abundant information due to their typical high sedimentation rates and susceptibility to environmental changes. Lipid biomarkers distributions in surface sediments were determined using gas chromatography (GC) and GC-mass-spectrometry in order to investigate the lipid biomarkers signature in sediments of four lakes of the Baikal region. They are linked to autochthonous and/or allochthonous sources, which can lead to distinct lipid molecular distributions. Lipid biomarkers of terrestrial origin (i.e. high-molecular weight n-alkanoic acids, n-alkanols, dicarboxylic acids, β-sitosterol) and aquatic source (i.e. short chain fatty acids, hydroxy fatty acids, etc.) were detected in all lakes in different ratios. The results of this study show the compatibility of different lipid biomarkers in assessing the origin of organic matter. Therefore, lipid molecular proxies in combination with molecular distribution of n-alkanes, dD or D/H ratios, palynological studies, etc. can be applied as paleoclimate and paleoenvironment proxies.