Identification of cryptotephra horizons in a North East Atlantic marine record spanning marine isotope stages 4 and 5a (similar to 60,000-82,000 a b2k)

• Published in: Quaternary International
• Main Authors: Abbott, Peter M., Davies, Siwan M., Austin, William E. N., Pearce, Nicholas J. G., Hibbert, Fiona D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: ICE-CORE; HIGH-RESOLUTION; LAST INTERGLACIAL PERIOD; VEDDE ASH; NORWEGIAN SEA; LATE QUATERNARY; GLASS SHARDS; TEPHRA LAYERS; VOLCANIC ASH LAYERS; SILICIC VOLCANISM; Greenland; Norwegian Sea; Rockall Trough; ice core; Iceland; North Atlantic; North East Atlantic
• Online Access: https://research-portal.st-andrews.ac.uk/en/researchoutput/identification-of-cryptotephra-horizons-in-a-north-east-atlantic-marine-record-spanning-marine-isotope-stages-4-and-5a-similar-to-6000082000-a-b2k(3ad52055-cae5-4648-a5b2-30b74ad8f593).html; https://doi.org/10.1016/j.quaint.2011.07.033

Tephrochronology is one of the few techniques that offer considerable, but as yet largely unrealised, potential for the correlation of North Atlantic palaeoclimatic archives spanning the MIS 4 and 5a substage period - a phase of pronounced global cooling during the initiation of the last glacial period. In this investigation, two previously unidentified rhyolitic tephra horizons believed to be sourced from Iceland were isolated within the giant piston core MD04-2822, retrieved from the Rockall Trough, North East Atlantic. One horizon was deposited at the beginning of Greenland Stadial 19 (similar to 70,150 a b2k) and the other around the cooling transition at the end of Greenland Interstadial 20 (similar to 75,320 a b2k). Density separation, EPMA and LA-ICP-MS techniques were utilised for the identification of these cryptotephra within the fine-fraction sediment (