Date (Creation)

2022-09-14

Date (Revision)

2022-09-14

Date (Publication)

2022-09-14

Date (released)

2022-09-14

Edition

1.0

Unique resource identifier

https://doi.org/10.5285/5a286921-9031-4abc-b227-79bce58f0640

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01667

Codespace

https://data.bas.ac.uk/

Unique resource identifier

NE/N011228/1

Codespace

award

Other citation details

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

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Antarctic Survey	Smith, James A.		Author
Newcastle University	Callard, Louise		Author
University of Colorado Boulder	Sánchez Montes, Maria Luisa		Author
Durham University	McClymont, Erin L.		Author
Durham University	Lloyd, Jeremy M.		Author
Leipzig University	Ehrmann, Werner		Author
Durham University	Roberts, David		Author
Durham University	Bentley, Michael J.		Author
Durham University	Jamieson, Stewart S. R.		Author
Liverpool John Moores University	Lane, Timothy P.		Author
University of Manchester	Darvill, Christopher M.		Author
NERC EDS UK Polar Data Centre		PDCServiceDesk@bas.ac.uk	Point of contact

Maintenance and update frequency

As needed

Maintenance note

Completed

Global Change Master Directory (GCMD) Science Keywords

• EARTH SCIENCE > Paleoclimate > Ocean/Lake Records > Sediments

Theme

• 79 degrees N

• Greenland

• Holocene

• epishelf lake

• ice shelf history

• palaeolimnology

Place

• Blaso, NE Greenland Greenland

GEMET - INSPIRE themes, version 1.0

• Geology

Access constraints

Other restrictions

Other constraints

no limitations to public access

Access constraints

Other restrictions

Other constraints

no limitations

Use constraints

License

Other constraints

Open Government Licence v3.0

Use constraints

Other restrictions

Other constraints

Data released under Open Government Licence V3.0:

Use constraints

Other restrictions

Other constraints

No restrictions apply.

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Climatology, meteorology, atmosphere

Begin date

2017-07-20

End date

2017-08-16

Supplemental Information

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.

Title

European Petroleum Survey Group (EPSG) Geodetic Parameter Registry

Date (Publication)

2008-11-12

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role
European Petroleum Survey Group		EPSGadministrator@iogp.org	Publisher

Unique resource identifier

urn:ogc:def:crs:EPSG::3031

Version

6.18.3

Hierarchy level

Dataset

Statement

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)

Metadata

File identifier

5a286921-9031-4abc-b227-79bce58f0640 XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2022-09-14

Metadata standard name

ISO 19115 Geographic Information - Metadata

Metadata standard version

ISO 19115:2003(E)

Metadata author

Organisation name	Individual name	Electronic mail address	Role
NERC EDS UK Polar Data Centre		polardatacentre@bas.ac.uk	Point of contact