Characterization of organic matter in marine sediments to estimate age offset of bulk radiocarbon dating ...

• Main Authors: Hansen, Katrine Elnegaard, Giraudeau, Jacques, Limoges, Audrey, Massé, Guillaume, Rudra, Arka, Wacker, Lukas, Sanei, Hamed, Pearce, Christof, Seidenkrantz, Marit-Solveig
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: Radiocarbon dating; Organic pyrolysis; Holocene; Marine sediments; Age offset; Bulk organic matter; Arctic; Baffin Bay; Baffin; Foraminifera*; Upernavik
• Online Access: https://dx.doi.org/10.3929/ethz-b-000517088; http://hdl.handle.net/20.500.11850/517088

Radiocarbon dating of Arctic marine sediment is often challenging due to the low availability of calcareous fossils. Consequently, bulk organic matter dating has at times been used to establish sediment core chronologies. Yet, radiocarbon dates based on bulk organic matter often appear to deviate vastly from dates based on fossils, mainly caused by input of allochthounous carbon, including terrigenous organic matter. In this study, we aim to examine the link between the composition of the bulk organic matter and the age offsets between the bulk radiocarbon dates and those obtained from calcareous foraminiferal tests. All samples are taken from the marine sediment core AMD14-204C from offshore Upernavik (eastern Baffin Bay). The radiocarbon dates for bulk organic matter are on average similar to 3000 years older than the radiocarbon dates based on foraminifera, but with changing age offsets throughout the record. To investigate the cause of this age offset and its variations over time, we applied core ... : Quaternary Geochronology, 67 ...