This dataset contains compound-specific hydrogen (δ2H) and carbon (δ13C) isotope compositions and concentrations of long-chain n-alkanes and fatty acids (n-alkanoic acids) from the ROT21 sediment record of Rotsee, Central Switzerland (47°04′10″N, 8°18′48″E, 419 m a.s.l.). Sediment cores were retrieved in October 2021 using a UWITEC gravity corer, and the dataset spans the past ~13,000 years based on 19 radiocarbon dates (terrestrial and aquatic macrofossils) integrated with 210Pb and 137Cs profiles (see De Jonge et al., 2025). Laboratory analyses were conducted between February 2023 and November 2024 at the University of Basel.
Sediment samples (~2–5 g) were sub-sampled, freeze-dried, spiked with internal standards (n-C19-alkanoic acid, n-C36-alkane, 2-octadecanone, and n-C21-alkanol), and extracted with dichloromethane/methanol (9:1, v/v) using an Accelerated Solvent Extractor (Dionex ASE 350, Thermo Fisher Scientific). Following saponification, neutral fractions were separated via silica gel chromatography, and fatty acids were converted to fatty acid methyl esters (FAMEs). Both n-alkanes and FAMEs were further purified to isolate saturated compounds using AgNO3-impregnated silica gel columns, then analyzed and quantified by gas chromatography with flame ionization detection (GC-FID). Peak areas were normalized to recovery standards to account for potential losses during sample handling, and compounds were identified by comparison with external standards.
Compound-specific δ2H and δ13C values were determined by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and normalized to the VSMOW-SLAP (δ2H) and VPDB (δ13C) scales. Analytical precision was ±3-5 ‰ for δ2H and ±0.2–0.3 ‰ for δ13C.
The dataset was generated to reconstruct past hydroclimate and vegetation dynamics in Central Europe using plant wax δ2H records. Full methodological details are provided in the study: Central Europe hydroclimate since the Younger Dryas inferred from vegetation-corrected sedimentary plant wax δ2H values (Santos et al., 2026).
The Younger Dryas was the final cold phase during the last deglaciation; it started with an abrupt cooling in the Northern Hemisphere within just a few years. However, the regional patterns of Younger Dryas cooling in the North Atlantic realm were complex and mechanistically not fully understood. We present sub-annually resolved fatty acid data from Meerfelder Maar covering the Allerød-Younger Dryas transition to revel forcing mechanisms behind the time-transgressive Younger Dryas cooling across the North Atlantic realm. Data were generated using Mass Spectrometry Imaging (MSI) on 65 cm long section from the MFM09-A5-UR core. MSI was performed using a 7T solarix XR Fourier transform-ion cyclotron resonance-mass spectrometer (FT-ICR-MS) coupled to a matrix-assisted laser desorption/ionization (MALDI) source equipped with a Smartbeam II laser (Bruker Daltonik, Bremen, Germany). We used average chain length (ACL) of long-chain fatty acids (C24, C26, C28) and three terrestrial aquatic ratios (TARs; TAR based on C26 and C16 (TAR=C26/(C26+C16)), TAR based on C24 and C16 (TARC24/(C24+C16)) and TAR based on C28, C26, C24, C16 and C14 (TAR(C24+C26+C28)/(C24+C26+C28+C14+C16)) fatty acids). Moreover, we present ACL based on gas chromatography data and stable carbon isotopes data from individual fatty acids (δ13C of C16, C24, C26, C28 and bishomohopanoic acid (δ13CBA)) from the same section in a lower resolution as supporting data.