Re-evaluation and extension of the Marine Isotope Stage 5 tephrostratigraphy of the Faroe Islands region : The cryptotephra record

• Published in: Palaeogeography, Palaeoclimatology, Palaeoecology
• Main Authors: Abbott, P.M., Austin, W.E.N., Davies, S.M., Pearce, N.J.G., Rasmussen, T.L., Wastegård, S., Brendryen, J.
• Other Authors: NERC, University of St Andrews.Geography & Sustainable Development, University of St Andrews.Marine Alliance for Science & Technology Scotland, University of St Andrews.Scottish Oceans Institute, University of St Andrews.St Andrews Sustainability Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Volcanic ash; Iceland; Marine sequences; Isochrons; Palaeoclimatic synchronisation; G Geography (General); SDG 14 - Life Below Water; G1; Faroe Islands; Norwegian Sea
• Online Access: https://hdl.handle.net/10023/5015; https://doi.org/10.1016/j.palaeo.2014.05.004; http://www.sciencedirect.com/science/article/pii/S0031018214002284

PMA, SMD, WENA and NJGP are supported by NERC through the SMART project (NE/F020600/1, NE/F02116X/1, NE/F021445/1). The research leading to the results for the MIS 4 and 5a tephra horizons has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement n° [259253]. PMA, SMD and NJGP acknowledge the support of the Climate Change Consortium of Wales (C3W). JB is funded by the Research Council of Norway through the INTERACT project (project no. 221999). Abstract Previous studies of marine sequences from the Faroe Islands region have identified a series of coarse-grained tephra horizons deposited during Marine Isotope Stage (MIS) 5. Here we reassess the MIS 5 tephrostratigraphy of the Faroe Islands region and focus on the cryptotephra deposits preserved within the fine-grained fraction of marine core LINK 16. We also extend the record to encompass the late MIS 6 and early MIS 4 periods. A density separation technique, commonly used for tephra investigations in lacustrine settings but rarely applied to marine sediments, is utilised to explore the fine-grained material and EPMA and LA-ICP-MS are employed to determine the major and trace element composition of individual tephra shards. In total, 3 basaltic and 3 rhyolitic Icelandic cryptotephra deposits with homogeneous geochemical compositions are identified — all of which have the potential to act as isochronous tie-lines. Geochemical results highlight that the Grímsvötn volcanic system of Iceland is the predominant source of the basaltic horizons and the Öraefajökull or Torfajökull systems are the likely sources of the rhyolitic deposits. Three of the horizons have been previously recognised in Faroe Islands region marine sequences, with two of these deposits traceable into a Norwegian Sea sequence. An early MIS 4 rhyolitic horizon is the most widespread deposit as it can be traced into the Norwegian Sea and to the south into a record from the Rockall Trough. Basaltic and ...