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Gletscher und Klima am Übergang vom Spätglazial zum Holozän in den Alpen

Gut datierte Gletschervorstöße sind eine wertvolle klimageschichtliche Informationsquelle, weil Gletscher unmittelbar auf Klimaänderungen reagieren. In diesem Zusammenhang ist der Zeitabschnitt von der ausgehenden Jüngeren Dryas (Grönland-Stadial 1) bis zum Ende des Boreals im frühen Holozän besonders interessant. Er ist durch eine sehr rasche Erwärmung um etwa 11.5 ka charakterisiert, die sich dann etwas gedämpfter weiter fortsetzte. Diese Erwärmung wurde durch eine Reihe von klimatischen 'events' (Präboreale Oszillation, Erdalen-event, 9.3 und 8.2 ka event) unterbrochen, die vor allem im europäisch-atlantischen Sektor kurze und kräftige Abkühlung brachten und im Alpenraum in einen Rahmen von allgemein gletscherungünstigen Klimaverhältnissen eingebettet sind. Das Projekt hat zum Ziel, die Gletschervorstöße in diesem Zeitraum näher zu durchleuchten. Der Schwerpunkt wird auf einem System von Moränen liegen, das besonders bei kleineren Gletschern gut erhalten ist, und das eine vermittelnde Stellung zwischen den Moränen der Jüngeren Dryas und denen des 'Little Ice Age' (Neuzeit) einnimmt. Bisher sind derartige Moränen erst an drei Stellen datiert, wobei sich widersprechende Alter und damit zeitliche Einstufungen ergaben (PBO, Erdalen event, 8.2 ka event). Besonders interessant ist daher die Frage, ob und wie kleine Alpengletscher auf den 8.2 ka event reagiert haben, und welche klimageschichtlichen Schlußfolgerungen sich daraus ableiten lassen. Die Testgebiete befinden sich in Gebieten, die für eine klimageschichtliche Interpretation günstig gelegen sind und das entsprechende Moräneninventar aufweisen. Es handelt sich dabei vor allem um die westliche Silvrettagruppe (nordwestlicher Alpenrand mit Übergang zum zentralen Alpenraum), das Karwendelgebirge (nördlicher Alpenrand) und die westlichen Ötztaler Alpen (inneralpines Trockengebiet). Die Datierung soll in bewährter Weise mit den kosmogenen Radionukliden 10Be und 36Cl in enger Zusammenarbeit mit dem Institut für Teilchenphysik an der ETHZ erfolgen. Für die klimageschichtliche Interpretation werden die Energie- und Massenbilanzgleichung an der Gleichgewichtslinie, empirische Niederschlags-Temperaturmodelle und positive Gradtagsmodelle herangezogen. Die dafür zusätzlich nötigen Klimainformationen (vor allem Sommertemperatur) werden aus allen sinnvoll verwertbaren Proxydatenquellen der entsprechenden Zeitabschnitte entnommen. Damit können Änderungen der Niederschlagsstrukturen im Alpenraum und Hinweise auf die atmosphärischen Zirkulationsverhältnisse in Zeiträumen eines raschen Klimawandels hergeleitet werden.

Plant wax composition of sediment core ROT21 from the Rotsee, Switzerland

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).

Radiocarbon dating and charcoal identification record from NEP 1, NEP 2, NEP 3, NEP 4, Nördlingen, southern Germany

The charcoal fragments found during the excavation of NEP soil profiles downstream of the course of the Eger River (on the northern outskirts of Nördlingen) were anthracologically examined and determined to the lowest possible taxonomic rank. Subsequently some of them were radiocarbon dated at the Curt-Engelhorn-Zentrum Archäometrie gGmbH (CEZA). The samples were pretreated with HCl, NaOH and HCl using the ABA method (Acid/Base/Acid). The ¹⁴C content was measured with a MICADAS AMS-System. Radiocarbon ages are given as uncalibrated measurements in "kiloyears before present".

XRF data sheet: Weiße Elster overbank silt-clay deposition (SC40 core, Salsitz transect)

We used stationary XRF spectrometry for analysing elemental composition of Holocene floodplain sediments from a recovered core form the Weiße Elster floodplain. For XRF sample preparation freeze-dried catchment sediments (8 g) were seaved (2mm) to discard the gravel fraction and large organic matter. Further homogenization was undertaken by grinding the samples with a vibratory Retsch mill MM 200. We created uniform pellets by pressing the powdered samples with a carbon-based binding agent in a Vaneox press at 20 t for 2 min. We conducted elemental analyses in a He atmosphere using a Spectro Xepos energy dispersive XRF spectrometer. The total drilling depth of SC40 core is 275 cm. We conducted stationary XRF measurements of 52 samples.

X-ray fluorescense (XRF) core scanning data of sediment core HZM19

Magnetic susceptibility of sediment core HZM19

Chemical parameters of sediment core HZM19

Relative abundance of diatoms from sediment core HZM19

A 16,000 year multiproxy record from lake Holzmaar (Germany): diatom and geochemical stratigraphies

Lacustrine environmental archives with annually laminated (varved) sediments permit a calendar-year chronology and allow calculation of precise sediment accumulation rates. We present multiproxy analyses of a varved sediment record from Holzmaar (West-Eifel Volcanic Field, Germany) for the last 16,000 years providing a continuous diatom stratigraphy supported by physical and chemical parameters with a centennial resolution. Patterns of diatom assemblages infer the trophic history of Holzmaar. There is a distinct variation at the Pleistocene/Lateglacial transition characterized by a replacement of Staurosira construens with Stephanodiscus minutulus, increases of Ca/Ti, TOC/TN ratios and biogenic silica, together suggesting an increase in lacustrine productivity and a shift of the lake's trophic status from oligotrophic to mesotrophic. These conditions remain during the Bölling/Alleröd interstadial. During the Younger Dryas stadial, there is a decrease on organic productivity as reflected by TOC, a subtle increase on benthic and epiphytic diatoms, indicating colder and dry conditions, and S. minutulus remains dominant suggesting increased winds. The Postglacial is dominated by Lindavia radiosa, S. minutulus and Nitzschia paleacea. The latter occurs between 9000-6000 cal yr BP together with an increase of TOC/TN and TS suggesting eutrophication with periodic anoxia during the Holocene Thermal Maximum. After 2200 cal yr BP, L. radiosa and Pantocsekiella comensis are dominant suggesting warmer conditions (especially during the Medieval Climate Anomaly) and thermal stability. Increased surface runoff is reflected in higher values of Ti and MS, suggesting more humidity and enhanced by anthropogenic disturbance. Moreover, the appearance of Aulacoseira subarctica is related to a cold and wet period coinciding with the Little Ice Age. In addition to environmental changes, our multiproxy analyses track human impact since the Middle Neolithic.

Documentation of sediment core WASA-N11

The cores show a sediment succession of the late Pleistocene and the Holocene. A core photograph is depicted, followed by a detailed core scetch and a depositional code for the depositional environment and facies. Samples taken for grain size, pollen, foraminifera, diatoms, macrobenthos, radiocarbon dating, XRD analysis and XRF data are marked in the columns right of the plot of the core. In the last column additional notes are given. The cores were taken in the backbarrier tidal flats of the Eastfrisian Island Norderney (central Wadden Sea, German North Sea coast) within the frame of the multidisciplinary national research project 'WASA – Wadden Sea Archive'. WASA has been undertaken to reconstruct submerged palaeo-landscapes in the central Wadden Sea. It was running from 2016 to 2020 (Bittmann et al. 2022). Each of the three cores were collected in the subital with a modified version of the vibrocorer VKG6 (medconsultant GmbH) which was used from aboard the research vessels FK SENCKENBERG (Senckenberg am Meer, SaM, Wilhelmshaven) and BURCHANA (Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, NLWKN, Norderney). The vibrocorer was deployed in full-weight load mode (1.1 t gravity weight) and was equipped with PVC liners of 5000 mm length maximum and 100 mm diameter. The cores were described based on the field proven core catalogue by Capperucci et al. (2022), which was developed on the base of all 140 cores taken in the area of Norderney within the WASA project. The core catalogue allows the identification of the local sedimentary sequences and their characteristic facies and depositional environments of the Late Pleistocene and Holocene of the central Wadden Sea.

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