5a286921-9031-4abc-b227-79bce58f0640 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2022-09-14 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Geochemical data (clay mineral, XRF-scanner and biomarker data) for core LC12 sediment record from Blaso, a large, epishelf lake in NW Greenland collected July-August 2017 2022-09-14 creation 2022-09-14 revision 2022-09-14 publication 2022-09-14 released 1.0 https://doi.org/10.5285/5a286921-9031-4abc-b227-79bce58f0640 doi GB/NERC/BAS/PDC/01667 https://data.bas.ac.uk/ NE/N011228/1 award Please cite this item as: Smith, J., Callard, L., Sánchez Montes, M., McClymont, E., Lloyd, J., Ehrmann, W., Roberts, D., Bentley, M., Jamieson, S., Lane, T., & Darvill, C. (2022). Geochemical data (clay mineral, XRF-scanner and biomarker data) for core LC12 sediment record from Blaso, a large, epishelf lake in NW Greenland collected July-August 2017 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/5a286921-9031-4abc-b227-79bce58f0640 The dataset comprises multi-proxy analyses of sediment core, LC12, extracted from Blaso, a large epishelf lake on the margin of 79 degree N Ice Shelf, NW Greenland in July-August 2017. The data are used to constrain ice shelf dynamics over the last ~8500 calibrated years before present (cal. years B.P., where present is A.D. 1950). A 2 m-long sediment core was recovered with a UWITEC KOL 'Kolbenlot' percussion piston corer to a total sediment depth of 5.24. Core LC12: 90 m water depth; 79.5948 degrees N, 22.44233 degrees E. Geochemical data for the LC12 sediment records consists of clay mineral, XRF-scanner and biomarker data. This project was funded by the Natural Environment Research Council (NERC) through Standard Grant NE/N011228/1. We thank the Alfred Wegner Institute, and particularly Angelika Humbert and Hicham Rafiq, for their significant logistic support through the iGRIFF project. Additional support was provided from Station Nord (Jorgen Skafte), Nordland Air, Air Greenland and the Joint Arctic Command. Naalakkersuisut, Government of Greenland, provided Scientific Survey (VU-00121) and Export (046/2017) licences for this work. No credit. completed Smith, James A. British Antarctic Survey Researcher author Callard, Louise Newcastle University Researcher author Sánchez Montes, Maria Luisa University of Colorado Boulder Researcher author McClymont, Erin L. Durham University Researcher author Lloyd, Jeremy M. Durham University Researcher author Ehrmann, Werner Leipzig University Researcher author Roberts, David Durham University Researcher author Bentley, Michael J. Durham University Researcher author Jamieson, Stewart S. R. Durham University Researcher author Lane, Timothy P. Liverpool John Moores University Researcher author Darvill, Christopher M. University of Manchester Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Paleoclimate > Ocean/Lake Records > Sediments theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher 79 degrees N Greenland Holocene epishelf lake ice shelf history palaeolimnology theme Blaso, NE Greenland Greenland place Geology theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions Data released under Open Government Licence V3.0: otherRestrictions No restrictions apply. url url crossReference url url crossReference url url crossReference url url crossReference url url crossReference textTable eng utf8 climatologyMeteorologyAtmosphere 22.44233 22.44233 79.5948 79.5948 2017-07-20 2017-08-16 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor text/csv text/plain bytes 338944 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=5a286921-9031-4abc-b227-79bce58f0640 WWW:LINK-1.0-http--link Get Data Download data download bytes 338944 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=5a286921-9031-4abc-b227-79bce58f0640 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Prior to analysis sediment samples were treated with 20 percent hydrogen peroxide to digest the organic material. Once the organic material has been digested the sample was centrifuged and then 20 ml distilled water plus 2 ml sodium hexametaphosphate was added to defloculate the sample. High-resolution elemental abundances were measured on the split core using a GEOTEK X-ray Fluorescence (MSCL-XRF) at 1 mm resolution. We use elemental ratios Ti/Ca as a proxy for terrigenous flux, while Mn/Fe and Br concentrations provides semi-quantitative information about lake oxygenation (Naeher et al., 2013) and marine organic carbon content (Ziegler et al., 2008) respectively. Ti contents in marine sediments is directly linked to terrigenous (siliciclastic) sediment supply delivered by fluvial and/or aeolian transport processes (Arz et al., 1999; Nace et al., 2014), while Ca concentrations reflect changes in the production of calcium carbonate (CaCO3) by marine plankton (Bahr et al., 2005). High Ti/Ca ratios are indicative of an increased terrigenous flux. The behaviour of Fe and Mn is strongly dependent on processes of oxidation and reduction. Reducing conditions are the result of O2 consumption during organic matter (OM) remineralisation, which releases Fe and Mn. Because Fe oxidises faster than Mn, high Mn accumulation and thus high(low) Mn/Fe ratios reflect oxic (anoxic) conditions. Bromine (Br) is used as a proxy for marine organic carbon, since bromine is found at higher concentrations in marine, compared to terrestrial, organic matter (Ziegler et al., 2008; Seki et al., 2019). Finally, an aliquot of the less than or equal to 2 micrometer fraction was used to determine the relative concentrations of the clay minerals smectite, illite, chlorite and kaolinite in LC12 using an automated powder diffractometer system (Rigaku MiniFlex) with CoK-alpha radiation (30 kV, 15 mA) at the Institute for Geophysics and Geology (University of Leipzig, Germany). The clay mineral identification and quantification followed standard X-ray diffraction methods (Ehrmann et al., 2011) and is used to reconstruct sediment provenance and pathways. A total of 22 sediment samples from LC12 were prepared for lipid biomarker analyses. Lipids were microwave-extracted from 0.4 to 2g of freeze-dried and homogenised sediment were extracted using dichloromethane:methanol (3:1) at an oven temperature of 70 degrees Celsius for two minutes following Kornilova and Rosell-Mele (2003). Internal standards of known concentration (5-alpha-cholestane, Heptatriacontane and 2 nonadecanone) were added to aid quantification. The extracted sediment was centrifuged at 2,500rpm for 5 minutes. The solvent was decanted and then taken to near-dryness with a stream of N2. The total lipid extract was separated into 3 fractions using glass Pasteur pipettes packed with extracted cotton wool and a 4 cm silica column (high purity grade pore size 60 Angstrom 220-440 mesh particle size, 35-75 micrometer particle size for flash chromatography, copy right Sigma Aldrich, size of particles). Sequential elution with Hexane, Dichloromethane and Methanol (4 columns each) yielded n -alkane, ketone and polar fractions, respectively. Biomarkers were quantified and identified using gas chromatography with flame ionisation (GC-FID) and mass spectrometry (GC-MS) as outlined in detail in Sánchez-Montes et al. (2020). The internal standards were used to calculate lipid mass, normalised to the original extracted dry weight of sediment. We employ a range of n-alkanes and ketones as environmental proxies, using a series of equations used to determine the relative contribution of bacteria, phytoplankton and grasses to sediments, as well as indicators of water temperature and salinity. The terrigenous and aquatic OM equations were normalised to the weight of the sediment extracted. Also, because Blaso has experienced bot...(5) Data collection: UWITEC KOL 'Kolbenlot' percussion piston corer GEOTEK X-ray Fluorescence (MSCL-XRF) asNeeded completed