Description: Elemental scans, organic geochemistry and stable isotope analysis is presented here from a stomach-oil deposit collected at Lake Untersee in central Dronning Maud Land (DML). Deposit WMM7 (sometimes called Antarctic mumiyo) was collected at -71.367 degN, 13.317 degE during the GeoMaud expedition (1995/1996), from the Untersee Oasis, Dronning Maud Land. The aim of the analysis is to investigate snow petrel diet during the Last Glacial stage (22-29 ka) and in turn to infer changing sea-ice conditions in the South Atlantic sector of the Southern Ocean (McClymont et al., Climate of the Past Discussions, submitted). The data include results from non-destructive XRF scanning (ITRAX core scanner, National Oceanography Centre, Southampton, U.K.), fatty acid distributions and fatty acid stable isotope ratios (Department of Geography, Durham University, Durham, U.K.) and bulk stable carbon and nitrogen isotope ratios (Department of Earth Sciences, Durham University, Durham, U.K.). The age-depth model is constrained by 6 new bulk radiocarbon measurements (CologneAMS, Cologne, Germany).

Description: This dataset contains radiocarbon (14C) ages analysed on the loess-paleosol sequences (LPS) Balta Albă Kurgan (Romania). The data was obtained to test the robustness of different dating methods (14C analysis, luminescence dating, magnetic stratigraphy, tephrochronology) on this type of sediment archive. The data set includes 14C ages obtained on bulk organic carbon (OC) and on specific n-alkanes and n-alkanoic acids (Compound-specific 14C analysis). Sample preparation for bulk OC 14C analysis included removal of root remains and a standard acid-alkali-acid (AAA) protocol chemical treatment. Bulk OC was converted to graphite and analysed for 14C at the CologneAMS facility at the University of Cologne (Rethemeyer et al., 2019). The background of this specific suite of samples was determined to 42,700±590 14C years (F14C=0.0049±0.0004, fraction modern, Reimer et al., 2004) with size matched standards. For compound-specific 14C analysis n-alkanes and n-alkanoic acids were purified from sediment samples by using standard wet-chemical methods (see Scheidt et al. in press). Isolation of individual compounds was achieved by using a gas chromatograph coupled to a preparative fraction collector (PCGC). 14C analysis was done with an elemental analyser coupled to a gas injection system (EA-GIS) periphery at CologneAMS (Stolz et al., 2019). F14C values of lipid biomarker compounds were corrected for a constant contamination of 1.0±0.1 µg C with an F14C value of 0.44±0.05 introduced during EA-GIS sample preparation and analysis, and for the PCGC processing blank (F14C=0.25±0.017 and 0.6±0.3 µg C). n-Alkanoic acids were corrected for the addition of one methyl group added during transesterification using mass balance. Calibration of 14C ages was done using the IntCal20 dataset (Reimer et al., 2020) and are given as 95% (2σ) confidence intervals. A detailed description of the analyses and discussion of the 14C ages can be found in the publication “Chronological assessment of the Balta Alba Kurgan loess-paleosol section (Romania) – a comparative study on different dating methods for a robust and precise age model” by Scheidt et al. in press. Reimer, P.J., Austin, W.E.N., Bard, E., Bayliss, A., Blackwell, P.G., Bronk Ramsey, C., et al. (2020). The INTCAL20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 CAL kBP). Radiocarbon, 1-33. doi: 10.1017/RDC.2020.41. Reimer, P.J., Brown, T.A., and Reimer, R.W. (2004). Discussion: reporting and calibration of post-bomb 14C data. Radiocarbon 46(3), 1299-1304. Rethemeyer, J., Gierga, M., Heinze, S., Stolz, A., Wotte, A., Wischhöfer, P., et al. (2019). Current Sample Preparation and Analytical Capabilities of the Radiocarbon Laboratory at CologneAMS. Radiocarbon 61(5), 1449-1460. doi: 10.1017/RDC.2019.16. Scheidt, S., Berg, S., Hambach, U., Klasen, N., Pötter, S., Stolz, A., Veres, D., Zeeden, C., Brill, D., Brückner, H., Kusch, S., Laag, C., Lehmkuhl, F., Melles, M., Monnens, F., Oppermann, L., Rethemeyer, J., Nett, J. (in press) Chronological assessment of the Balta Alba Kurgan loess-paleosol section (Romania) – a comparative study on different dating methods for a robust and precise age model. Frontiers in Earth Science, section Sedimentology, Stratigraphy and Diagenesis Stolz, A., Dewald, A., Heinze, S., Altenkirch, R., Hackenberg, G., Herb, S., et al. (2019). Improvements in the measurement of small 14CO2 samples at CologneAMS. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 439, 70-75. doi: https://doi.org/10.1016/j.nimb.2018.12.008.

Description: XRF analysis of stomach-oil deposit WMM7.

Description: Total nitrogen %, total organic carbon % and bulk stable isotope ratios of carbon and nitrogen for stomach-oil deposit WMM7. Standard deviations reported for replicate analyses.

Description: Fatty acid and selected pigment distributions from stomach-oil deposit WMM7. Pigments are reported according to the absorbance at 4 key wavelengths (e.g. P410 = absorbance at 410 nm). Absorbances are reported normalised to extracted mass of stomach-oil deposit (abs g-1) and normalised to total organic carbon content (abs gTOC-1).

Description: Fatty acid stable carbon isotope ratios from stomach-oil deposit WMM7. Standard deviations reported for duplicate measurements.

Description: Here, we compile an extensive global surface sediment dataset of OH-isoGDGTs as well as regular isoprenoid GDGTs (isoGDGTs), with both data generated at NIOZ and previously published data from other laboratories. We explore recently developed temperature proxies based on hydroxylated isoprenoid Glycerol Dialkyl Glycerol Tetraethers (OH-isoGDGTs), such as %OH, RI-OH, RI-OH' and OHC for their potential for reconstructing past temperature changes. The data contains contains temperature records based on TEX86, TEX86OH, %OH, RI-OH, RI-OH', OHC from sediment core Co1010 which was retrived from the Prydez Bay. This dataset is related to the study 'Evaluating isoprenoidal hydroxylated GDGT-based temperature proxies in surface sediments from the global ocean'.

Description: The data set comprises radiocarbon (14C) ages obtained on three sediment cores (Co1010, Co1305 and PS81/283) and additional information on the sample preparation of compound-specific 14C ages and carbonates. 14C ages were measured on different fractions of organic and inorganic carbon extracted from the sediments: bulk organic carbon (bulk OC), carbonates (foraminifers and mollusc shell debris) and fatty acids of different chain lengths (FA). The ages are presented and discussed in Berg et al. in review (Compound-specific radiocarbon analysis of (Sub-)Antarctic coastal marine sediments - potential and challenges for chronologies)

Description: The dataset comprises data on the lipid composition (carboxylic acids and alkanols) and stable isotope values (δ13C and δ15N) obtained from fresh stomach oils and sub-stomach oil deposits of snow petrels (Pagodroma nivea). The samples were collected in different un-glaciated regions of East Antarctica (Dronning Maud Land, Mac. Robertson Land, Prince Charles Mountains and Windmill Islands). The stomach oils and sub-fossil stomach oil deposits were analyzed to investigate the paleodiet of the birds and to relate information of paleodiet to past environmental conditions. The alkanoic acids and alkanols were analysed from total lipid extracts by capillary gas chromatography with GC-FID (Gas chromatograph with Flame ionization detector) and GC-MS (single quadrupole mass spectrometer coupled with gas chromatograph). Total lipid extracts were analysed for the δ13C isotopic composition. The un-soluble residues, retained after lipid extraction, was analysed for δ13C and δ15N isotopic composition. This work was funded by the Deutsche Forschungsgemeinschaft (DFG) in the framework of the priority program "Antarctic Research with comparative investigations in Arctic ice areas" (grants BE 4764/5-1 and BE 4764/6-1).