Tracing marine cryptotephras in the North Atlantic during the last glacial period: Improving the North Atlantic marine tephrostratigraphic framework
|Author(s)||Abbott Peter M.1, 2, 3, 4, Griggs Adam J.1, Bourne Anna J.1, 5, Chapman Mark R.6, Davies Siwan M.1|
|Affiliation(s)||1 : Swansea Univ, Coll Sci, Dept Geog, Singleton Pk, Swansea SA2 8PP, W Glam, Wales.
2 : Cardiff Univ, Sch Earth & Ocean Sci, Pk Pl, Cardiff CF10 3AT, S Glam, Wales.
3 : Univ Bern, Inst Geol Sci, Baltzerstr 1 3, CH-3012 Bern, Switzerland.
4 : Univ Bern, Oeschger Ctr Climate Change Res, Baltzerstr 1 3, CH-3012 Bern, Switzerland.
5 : Univ Southampton, Geog & Environm, Univ Rd, Southampton SO17 1BJ, Hants, England.
6 : Univ East Anglia, Sch Environm Sci, Norwich Res Pk, Norwich NR4 7TJ, Norfolk, England.
|Source||Quaternary Science Reviews (0277-3791) (Pergamon-elsevier Science Ltd), 2018-06 , Vol. 189 , P. 169-186|
|WOS© Times Cited||14|
|Keyword(s)||Quaternary, Palaeoceanography, Tephrochronology, North Atlantic, Tephra framework, Marine cores|
Tephrochronology is increasingly being recognised as a key tool for the correlation of disparate palae-oclimatic archives, underpinning chronological models and facilitating climatically independent comparisons of climate proxies. Tephra frameworks integrating both distal and proximal tephra occurrences are essential to these investigations providing key details on their spatial distributions, geochemical signatures, eruptive sources as well as any available chronological and/or stratigraphic information. Frameworks also help to avoid mis-correlation of horizons and provide important information on volcanic history. Here we present a comprehensive chronostratigraphic framework of 14 tephra horizons from North Atlantic marine sequences spanning 60-25 cal ka BR Horizons previously discovered as visible or coarse-grained deposits have been combined with 11 newly recognised volcanic deposits, identified through the application of cryptotephra identification and characterisation methods to a wide network of marine sequences. Their isochronous integrity has been assessed using their physical characteristics. All horizons originated from Iceland with the vast majority having a basaltic composition sourced from the Grimsvotn, Kverkfjoll, Hekla/Vatnafjoll and Katla volcanic systems. New occurrences, improved stratigraphic placements and a refinement of the geochemical signature of the NAAZ II are reported and the range of the FMAZ IV has been extended. In addition, several significant geochemical populations that further investigations could show to be isochronous are reported. This tephra framework provides the foundation for the correlation and synchronisation of these marine records to the Greenland ice-cores and European terrestrial records to investigate the phasing, rate, timing and mechanisms controlling rapid climate changes that characterised the last glacial period.