The carbon isotope signatures and the content of polycyclic aromatic hydrocarbons (PAHs) in the pedogenic material of inclusions in ice wedges of the Batagay yedoma (Yakutia) are studied. The mean concentration of 11 PAHs is 170 ppb (minimum, 7 ppb and maximum, 430 ppb) and the mean δ13С value in soil lipids is -29‰ (minimum, -31.1‰ and maximum, -26.2‰). The prevalent polyarenes in associations are naphthalene homologs and phenanthrene. Trace amounts of heavy PAHs, including benzo[a]pyrene (an indicator of pyrogenic processes), are also detectable. The PAH contents and δ¹³С values in ice wedges show the trend of a decrease with depth. The δ¹³С values and PAH content suggest a pedogenic origin of the deposit: therefore, PAHs originate from plant residues and wildfires. The observed trend of changes in the concentrations of polyarenes along the ice wedge may be associated with the changes in landscapes in the Late Pleistocene.

Data was submitted and proofread by Yurij K Vasil'chuk and Lyubov Bludushkina at the faculty of Geography, department of Geochemistry of Landscapes and Geography of Soils, Lomonosov Moscow State University.The samples are represented by sediment extracted from ice wedges after ice melting in a plastic container. Content of organic carbon (%), δ¹³С values (‰), and PAH content was measured in samples from the Batagay ice wedges.The sediment was dried to assess the carbon content in dry samples. The carbon content was measured at the Ecological and Geochemical Center of the Geographical Faculty of Lomonosov Moscow State University on a Vario EL III v. 4.01 (Elementar Analysen systeme GmbH, Germany) CHNS analyzer using sulfanilic acid (Merck; 41.610% C) as a standard.The samples (hexane extracts) were analyzed for PAHs content at the Laboratory of Carbonaceous Substances in the Biosphere, Department of Landscape Geochemistry and Soil Geography, Geographical Faculty, Lomonosov Moscow State University, by spectrofluorometry (Shpol'skii method) using a cryounit (Pikovskii et al., 2017).The isotopic composition of lipid compounds was determined by mass spectrometry. The lipids were separated from soil inclusions in the ice wedges by cold chloroform and hexane extraction (Korchagina, Chetverikova, 1976). The isotopic composition of carbon was determined at the Isotope Laboratory of the Faculty of Geography, Lomonosov Moscow State University, on a Delta-V Plus isotope ratio mass spectrometer with a standard EA 1112 HT O/H-N/C element analyzer. IAEA-CH-3, IAEA-CH-6, IAEA-600, and USGS-24 international standards were used for measurements; δ¹³C determination accuracy was ±0.2‰.