/* DATA DESCRIPTION:
Citation:	Mayers, Kyle M J; Vollmar, Nele Manon; Cordier, Tristan; Weiner, Agnes K M; Müller, Juliane; De Schepper, Stijn (2026): Radiocarbon dates from Yermak Plateau sediment core KH21-234-34GC1 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.989273
Abstract:	Radiocarbon dates were determined by picking shells of Neogloboquadrina pachyderma at four depths from marine sediment core KH21-234-34GC collected from the Yermak Plateu (81.2199280 ˚N, 2.3710955˚E ) with a gravity corer at 1011m water depth during cruise KH21-234. Accelerator mass spectrometry (AMS) 14C dates from the radiocarbon lab at ETH Zurich, and calibrated ages were calculated used the functions BchronCalibrate:sampleAges and Bchronology:PredictAges from the statistical package BChron (version 4.7.7).
Keyword(s):	Arctic; Dinoflagellate; gene copy number; Magnetic susceptibility; Radiocarbon; Sea ice
Supplement to:	Mayers, Kyle M J; Vollmar, Nele Manon; Cordier, Tristan; Weiner, Agnes K M; Müller, Juliane; Larsen, Aud; De Schepper, Stijn (2026): First-year sea ice history in the Arctic Ocean inferred from ancient DNA of Polerella glacialis over the past 50,000 years. Earth and Planetary Science Letters, 678, 119809, https://doi.org/10.1016/j.epsl.2025.119809
Funding:	European Research Council (ERC), grant/award no. 101118519: Into the Blue - Resolving past Arctic greenhouse climate (i2B) (URI: doi:10.3030/101118519)
	Horizon 2020 (H2020) (URI: https://ec.europa.eu/programmes/horizon2020/), grant/award no. 818449: Genetic information for Arctic sea ice study (URI: doi:10.3030/818449)
Coverage:	LATITUDE: 81.219928 * LONGITUDE: 2.371096
	DATE/TIME START: 2021-07-07T14:42:29 * DATE/TIME END: 2021-07-07T14:42:29
	MINIMUM DEPTH, sediment/rock: 0.69 m * MAXIMUM DEPTH, sediment/rock: 4.54 m
Event(s):	KH21-234-34GC * LATITUDE: 81.219928 * LONGITUDE: 2.371096 * DATE/TIME: 2021-07-07T14:42:29 * ELEVATION: -1011.0 m * Recovery: 466 cm * CAMPAIGN: KH21-234 (URI: https://hdl.handle.net/11250/3022675) * BASIS: Kronprins Haakon (URI: https://npolar.no/en/kronprins-haakon/) * METHOD/DEVICE: Gravity corer (GC)
Parameter(s):	Site (Site) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no)
	DEPTH, sediment/rock [m] (Depth sed) * GEOCODE * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no)
	Age, dated [ka] (Age dated) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * METHOD/DEVICE: Age, 14C AMS (URI: https://doi.org/10.1146/annurev.ns.30.120180.002253) * COMMENT: 14C AMS
	Age, dated, error [±] (Age dated e) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * METHOD/DEVICE: Age, 14C AMS (URI: https://doi.org/10.1146/annurev.ns.30.120180.002253)
	Laboratory code/label (Lab label) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * COMMENT: Sample ID
	Reference/source (Reference) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no)
	Calibration (Calibration) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * COMMENT: Calibration curve
	Calendar age, minimum/young [ka BP] (Cal age min) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * METHOD/DEVICE: Age, 14C calibrated * COMMENT: 2.5%
	Calendar age [ka BP] (Cal age) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * METHOD/DEVICE: Age, 14C calibrated
	Calendar age, maximum/old [ka BP] (Cal age max) * PI: Mayers, Kyle M J (https://orcid.org/0000-0001-9595-8702, kyma@norceresearch.no) * METHOD/DEVICE: Age, 14C calibrated * COMMENT: 97.5%
License:	Creative Commons Attribution 4.0 International (CC-BY-4.0) (URI: https://creativecommons.org/licenses/by/4.0/)
Status:	Curation Level: Enhanced curation (URI: https://wiki.pangaea.de/wiki/Curation_levels)
Size:	36 data points
*/
Site	Depth sed [m]	Age dated [ka]	Age dated e [±]	Lab label	Reference	Calibration	Cal age min [ka BP]	Cal age [ka BP]	Cal age max [ka BP]
KH21-234	0.69	4.410	0.062	118423.1.1	this study	marine20	4.145	4.371	4.601
KH21-234	1.99	10.252	0.098	118424.1.1	this study	marine20	10.888	11.219	11.568
KH21-234	3.29	17.479	0.149	118425.1.1	this study	marine20	19.767	20.202	20.603
KH21-234	4.54	55.500	10.947	118426.1.1	this study	None (extrapolated age)	37.850	48.889	54.717