Sediment lithology and stable isotope composition of organic matter in a core from a cirque in the Krkonoše Mountains, Czech Republic

• Published in: Journal of paleolimnology 2010-04, Vol.43 (4), p.609-624
• Main Authors: Engel, Zbyněk, Skrzypek, Grzegorz, Paul, Debajyoti, Drzewicki, Wojciech, Nývlt, Daniel
• Format: Article
• Language: English
• Subjects: Carbon; Climate Change; Earth and Environmental Science; Earth Sciences; Freshwater & Marine Ecology; Geology; Lithology; Mountains; Nitrogen; Organic matter; Original Paper; Paleolimnology; Paleontology; Peat; Physical Geography; Sand; Sedimentation; Sedimentology; Sediments; Silt; Sphagnum; Stable isotopes; Stratigraphy; Valleys
• ISSN: 0921-2728; 1573-0417
• DOI: 10.1007/s10933-009-9356-1

This study presents detailed lithostratigraphy and stable carbon and nitrogen isotopic variations in a 520-cm-long sediment core from a cirque basin in the Labský důl Valley, Krkonoše Mountains, Czech Republic. Detailed study of the core reveals five major periods of sedimentation during the last 7600 years: silt and sand deposition during ~7.6–5.1 ka cal BP, Sphagnum peat accumulation during ~5.1–4.0 ka cal BP, sandy silt and sand during ~4.0–2.8 ka cal BP, raised peat bog during ~2.8–2.0 ka cal BP ( Sphagnum peat), and sedimentation of sandy silt since ~2.0 ka cal BP. The δ 13 C values of the organic matter in the core vary in the range typical for C3 plants, from −24.35 to −27.68‰, whereas the δ 15 N values vary from −2.65 to +4.35‰. Core sections having ash contents ≥70% have δ 15 N > 1‰ and δ 13 C 10%, primarily for sand and silt horizons. On the other hand, poor correlations between δ 13 C and C:N ratio, as well as δ 15 N and C:N ratio, were observed in Sphagnum peat layers (45–125 and 185–265 cm). We conclude that the primary stable isotope variations are not preserved in the layers where significant correlation between δ 15 N and C:N ratio is observed. The relatively small δ 13 C variation in the uppermost Sphagnum peat layer suggests stable temperature during ~2.8–2.0 ka cal BP.