Characterization of Organic Matter in Areas of Methane Emission in the Laptev Sea (Expedition 2016)

The paper presents data on the characteristics of organic matter in bottom sediment samples collected during the 2016 expedition in the Laptev Sea (northern polygon, outer shelf zone and south-eastern part of the sea). The distribution of total organic carbon over the study area is shown. Samples were analysed by Rock-Eval analytical pyrolysis, 13C isotope analysis and chromatography-mass spectrometry. The organic matter composition included hopanoids similar to those found in the 2011 expedition samples taken from the first discovered mega-seepage area. The hopanoids detected are thought to be derived from the activity of methanotrophic microorganisms. The peculiar distribution of n-alkanes, hopanoids and traces of steranes found in samples confined to rift zones may indicate the migration of petroleum fluids.