Current Sample Preparation and Analytical Capabilities of the Radiocarbon Laboratory at CologneAMS

Rethemeyer, Janet; Gierga, Merle; Heinze, Stefan; Stolz, A.; Wotte, Anja; Wischhöfer, Philipp; Berg, Sonja; Melchert, JO; Dewald, Α.

doi:10.1017/rdc.2019.16

Cited by 33 publications

(35 citation statements)

References 28 publications

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“…The radiocarbon dating of organic material from host deposits and wedge-ice inclusions was performed at CologneAMS (University of Cologne, Germany; Rethemeyer et al, 2019), at Leibniz Laboratory for Radiometric Dating and Stable Isotope Research (Kiel, Germany; Grootes et al, 2004) and at MICADAS (Mini Carbon Dating System, AWI, Bremerhaven, Germany; Opel et al, 2019). In total, eight new radiocarbon dates from distinct floral or faunal macrofossils (>1 mm in size) and seven re-calibrated dates from H. Meyer, Dereviagin, Siegert, Schirrmeister, et al (2002) and are considered (Table S1).…”

Section: Radiocarbon Datingmentioning

confidence: 99%

Northeast Siberian Permafrost Ice‐Wedge Stable Isotopes Depict Pronounced Last Glacial Maximum Winter Cooling

Wetterich

Meyer

Fritz

et al. 2021

Geophysical Research Letters

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Stable isotopes (δ18O, δD) of wedge ice hold potential to reconstruct past winter climate conditions. Here, we present records of the marine isotope stages (MIS) 3 and 2 including the last Glacial maximum (LGM) from Bol’shoy Lyakhovsky Island (NE Siberia). MIS 3 wedge ice dated from 52 to 40 Kyr b2k varies between −32 and −29‰ in δ18O. Colder LGM conditions are implied by δ18O of −37‰ around 25 Kyr b2k. Similar Deuterium excess values indicate comparable moisture sources during MIS 3 and MIS 2. Regional LGM climate reconstructions depend on the seasonal resolution of the proxies and model simulations. Our wedge‐ice record reflects coldest winters during global minima in atmospheric CO2 and sea level. The extreme LGM winter cooling is not represented in model projections of global LGM climate where West Beringia shows noticeably little cooling or even warming in mean annual temperatures compared to the late Holocene.

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Section: Radiocarbon Datingmentioning

confidence: 99%

Northeast Siberian Permafrost Ice‐Wedge Stable Isotopes Depict Pronounced Last Glacial Maximum Winter Cooling

Wetterich

Meyer

Fritz

et al. 2021

Geophysical Research Letters

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“…For core PS81/283‐1, a different protocol was used. Samples were treated with a standard acid‐alkali‐acid extraction to obtain humins, which are assumed to be representative for bulk OC (Rethemeyer et al, 2019). OC in the pretreated sediments was converted to graphite using an automated graphitization system (AGE) and analyzed at the CologneAMS facility.…”

Section: Methodsmentioning

confidence: 99%

Compound‐Specific Radiocarbon Analysis of (Sub‐)Antarctic Coastal Marine Sediments—Potential and Challenges for Chronologies

Berg

Jivcov

Kusch

et al. 2020

Paleoceanog and Paleoclimatol

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In Antarctic and Subantarctic environments, 14 C-based age determination is often challenging due to unknown reservoir effects, low organic carbon contents of sediments, and high contributions of petrogenic (14 C-free) carbon in ice marginal settings. In this study, we evaluate possible benefits and challenges of compound-specific radiocarbon analysis (CSRA) as a tool for age determination of marine Antarctic and Subantarctic sediment sequences. We present a comprehensive data set of 14 C ages obtained on bulk organic carbon, carbonates, and on fatty acids (FA) from three coastal marine sediment cores from Subantarctic South Georgia and East Antarctica. Low molecular weight (LMW) FA represent the least 14 C-depleted fraction, indicating that the phytoplankton-derived compounds can be a means of dating sediments. In contrast, vascular plant-derived high molecular weight FA are systematically depleted in 14 C relative to the low molecular weight homologues, reflecting processes such as soil formation/erosion in the catchment. Comparative age-depth models show significant differences, depending on the material used for the respective models. While the land plant-derived FA may lead to an overestimation of the actual sediment age, LMW FA reveal complex aquatic reservoir effects. Bulk sedimentary organic carbon 14 C ages likely provide appropriate age estimates in settings with low petrogenic carbon input in the Antarctic, whereas CSRA has the potential to produce improved age control in settings with high contributions of petrogenic carbon.

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“…Finally, the extracted material was rinsed using deionized water to remove and dissolve any residual sodium polytungstate. The isolated bulk organic and terrestrial plant remains were pretreated according to the standard protocol for organic materials and converted to elemental carbon by graphitization (Rethemeyer et al, 2019). Samples were measured at the CologneAMS centre at the University of Cologne.…”

Section: Radiocarbon Dating 185mentioning

confidence: 99%

A 62-ka geomagnetic palaeointensity record from the Taymyr Peninsula, Russian Arctic

Scheidt

Lenz

Egli

et al. 2021

Preprint

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Abstract. This work represents the first palaeomagnetic study carried out on the sedimentary record of lake Levinson-Lessing, which is the deepest lake in northern Central Siberia. Palaeomagnetic analyses were carried out on 730 discrete samples from the upper 38 m of the 46 m-long core Co1401, which was recovered from the central part of the lake. Alternating field demagnetisation experiments were carried out to obtain the characteristic remanent magnetisation. The relative palaeointensity is determined using the magnetic susceptibility, the anhysteretic remanent magnetization and the isothermal remanent magnetization for normalization of the partial natural remanent magnetization. The chronology of Co1401 derives from accelerated mass spectrometer radiocarbon ages, optically stimulated luminescence dating, and correlation of the relative palaeointensity of 642 discrete samples with the GLOPIS-75 reference curve. This study focuses on the part >10 ka but although includes preliminary results for the upper part of the core. The record includes the geomagnetic excursions Laschamps and Mono Lake, and resolves sufficient geomagnetic features to establish a chronology that continuously covers ~62 ka. The results reveal continuous sedimentation and high sedimentation rate between 45 and 95 cm ka−1. High lock-in depths are suggested from the low variability of the magnetic record compared to data sets of reference records with lower sedimentation rate. Although the horizontal component of the characteristic remanent magnetization can only be used with caution because Co1401 was cored without core segment overlap, the magnetic record of Co1401 is the only high-resolution record of relative palaeointensity and palaeosecular variations from the Arctic tangent cylinder going back to ~62 ka.

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Current Sample Preparation and Analytical Capabilities of the Radiocarbon Laboratory at CologneAMS

Cited by 33 publications

References 28 publications

Northeast Siberian Permafrost Ice‐Wedge Stable Isotopes Depict Pronounced Last Glacial Maximum Winter Cooling

Northeast Siberian Permafrost Ice‐Wedge Stable Isotopes Depict Pronounced Last Glacial Maximum Winter Cooling

Compound‐Specific Radiocarbon Analysis of (Sub‐)Antarctic Coastal Marine Sediments—Potential and Challenges for Chronologies

A 62-ka geomagnetic palaeointensity record from the Taymyr Peninsula, Russian Arctic

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