The carbon-to-nitrogen (C/N) ratio may provide information about the origin of the preserved organic matter in the sediment. The content of carbon and nitrogen in the sediment was measured by the Euro EA (HEKAtech GmbH) analyzer in 1-2 mg samples by burning it at a temperature of 920°C under a flow of high purity helium in the laboratory of the Geochronology of the Cenozoic at the Institute of Archaeology and Ethnography (Novosibirsk, Russia). Urea STD PN33840002 (ThermoScientific) was used for calibration as a reference for the measurement of these elements. The precision of measured values was less than 1% for carbon and nitrogen.