XRF, grain size, and biogeochemical characteristics of a sediment core from Lake Malaya Chabyda, Central Yakutia

• Main Authors: Biskaborn, Boris K, Hughes-Allen, Lara, Bouchard, Frédéric, Hatte, Christine, Pestryakova, Luidmila A, Diekmann, Bernhard, Subetto, Dmitry A, Meyer, Hanno
• Format: Dataset
• Language: English
• Published: PANGAEA 2021
• Subjects: AWI_Envi; AWI Arctic Land Expedition; COMPCORE; Composite Core; Holocene; Lake Malaya Chabyda; Yakutia; Russia; Lake sediment core; Late Pleistocene; organic carbon; Paleolimnology; PG2201_site; Polar Terrestrial Environmental Systems @ AWI; RU-Land_2013_Yakutia; Siberian permafrost; stable carbon isotopes δ13C; Yakutia2013; Arctic; Yakutsk; Chabyda; Alfred Wegener Institute; Ice; permafrost
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.933411; https://doi.org/10.1594/PANGAEA.933411

Eight overlapping sediment cores, representing an approximately 6.6 m–long composite sequence, were collected on March 24, 2013 from Lake Malaya Chabyda in Central Yakutia (exact coring location 61°57.509' 129°24.500'). Sampling was conducted during a German–Russian Expedition (“Yakutia 2013”) as a cooperation between the North Eastern Federal State University in Yakutsk (NEFU) and the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI). To penetrate ca. 1 m of lake ice cover, 250-mm-diameter holes were drilled using a hand-held Jiffy ice auger. Water depth was measured using an Echo sounder (HONDEX PS-7 LCD) and a calibrated rope for verification. 100 cm-long parallel cores were collected at 2 m water depth using a Russian peat corer and supported by an UWITEC gravity coring system. Cores were stored in waterproof sealed, transparent PVC plastic tubes in cool and dark conditions. After the field season, the cores were transported to Potsdam, Germany and stored at 4°C in the cold rooms at AWI. The cores did not experience any visible drying or surface oxidation during storage. High–resolution X–ray fluorescence (XRF) analyses were carried out with 10 mm resolution on the entire sequence using an Avaatech XRF core scanner at AWI (Bremerhaven, Germany) with a Rh X-ray tube at 10 kV (without filter, 12 s, 1.5 mA) and 30 kV (Pd-thick filer, 15 s, 1.2 mA). The sediment surface was cleaned, leveled, and covered with a 4µm ultralene foil to avoid sediment desiccation prior to XRF scanning. Individual element counts per second (CPS) were transformed using a centered log transformation (CLR) and element ratios were transformed using an additive log ratio (ALR) to account for compositional data effects and reduce effects from variations in sample density, water content, and grain size. Statistical analysis was completed using the Python programming language (Python Software Foundation, https://www.python.org/). XRF analysis of the sequence indicated 24 detectable elements and a subset of these ...