Bulk sedimentology of the Batagay thaw slump, Northeastern Siberia

• Main Authors: Ashastina, Kseniia, Schirrmeister, Lutz, Scheidemann, Dyke, Fuchs, Margret C, Kienast, Frank
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2017
• Subjects: Sample ID; DEPTH, sediment/rock; Ice content; Nitrogen, total; Carbon, total; Carbon, organic, total; Carbon, organic, total/Nitrogen, total ratio; Calcium carbonate; Grain size, mean; Size fraction < 0.002 mm, clay; Size fraction 0.020-0.002 mm; Size fraction 0.063-0.020 mm, coarse silt; Size fraction 0.200-0.063 mm, fine sand; Size fraction > 0.200 mm; Susceptibility, specific, low-field mass-normalized; Susceptibility, specific, high-field mass-normalized; δ13C; Unit; Outcrop sample; Element analyser CNS, Elementar Vario EL III; Element analyser CNS, elementar Vario MAX C; Calculated; Bartington MS2B bulk sensor; Mass spectrometer Finnigan Delta-S; Dee; Ice; permafrost; Siberia
• Online Access: https://dx.doi.org/10.1594/pangaea.877343; https://doi.pangaea.de/10.1594/PANGAEA.877343

We described the Batagay permafrost sequence during the June 2014 field campaign. The 60m high outcrop was sampled from top to bottom along its height, ideally in 1m steps, but depending on its accessibility. The sampling procedure was carried out as follows: (1) the cryolithological characteristics at each sampling point were described and photographed, (2) the sampling zone was cleaned, and (3) frozen deposits were taken using a hammer and a chisel and placed into plastic bags. The wet sediments were air-dried in the field and split into subsamples for sedimentological and biogeochemical analysis in the laboratories of the Alfred Wegener Institute in Potsdam.Total carbon (TC) and total nitrogen (TN) were measured with a vario EL III element analyser and the total organic carbon (TOC) content was measured with a vario MAX analyser. Using the TOC and TN values, the TOC = TN (C = N) ratio was calculated to deduce the degree of organic matter decomposition. The lower the C/N ratio is, the higher the decomposition degree and vice versa. For TOC and stable carbon isotope (d13C) analyses, samples were decalcified for 3 h at 95 °C by adding a surplus of 1.3 N HCl. Total inorganic carbon (TIC) content was calculated by subtracting TOC from TC. Using TIC values, the carbonate content as CaCO3 was estimated via the ratios of molecular weight. The d13C of TOC values was measured with a Finnigan Delta S mass spectrometer and expressed in delta per mil notation (d, per mil) relative to the Vienna Pee Dee Belemnite (VPDB) standard with an uncertainty of 0.15 per mil. Variations in d13C values indicate changes in the local plant association and in the degree of organic matter decomposition. Lower d13C values correspond to less-decomposed organic matter, while higher d13C values reflect stronger decomposition. Mass-specific magnetic susceptibility (MS) indicative of magnetic and magnetizable minerals was measured using Bartington MS2 instruments equipped with the MS2B sensor type. The data are expressed in 10-8 m3 kg-1 (SI).