Quaternary sediment dynamics in the Belgica mound province, Porcupine Seabight: ice-rafting events and contour current processes

Type Article
Date 2007-02
Language English
Author(s) Van Rooij D.1, 2, Blamart D.2, Richter T.3, Wheeler A.4, 5, Kozachenko M.6, Henriet J.-P.1
Affiliation(s) 1 : Univ Ghent, Renard Ctr Marine Geol, B-9000 Ghent, Belgium.
2 : CEA, CNRS, LSCE, Lab Mixte, F-91198 Gif Sur Yvette, France.
3 : Royal Netherlands Inst Sea Res NIOZ, NL-1790 AB Den Burg, Netherlands.
4 : Univ Coll Cork, Dept Geol, Cork, Ireland.
5 : Univ Coll Cork, Environm Res Inst, Cork, Ireland.
6 : Univ Coll Cork, Coastal & Marine Resources Ctr, Cork, Ireland.
Source International Journal Of Earth Sciences (1437-3254) (Springer), 2007-02 , Vol. 96 , N. 1 , P. 121-140
DOI 10.1007/s00531-006-0086-6
WOS© Times Cited 36
Keyword(s) contourite, ice-rafting event, British-Irish ice sheet, Porcupine Basin, coral banks
Abstract The Belgica cold-water coral banks on the eastern slope of the Porcupine Seabight are closely associated with bottom currents. In order to better understand the local temporal and spatial characteristics, as well as the palaeoclimatologic influences, a 26 m long core, taken on a small contourite drift, was studied. This sediment record of approximately 100 ka BP reveals new insights into the regional glacial and sedimentary processes, which are intrinsically linked to several geological, climatological, biological and hydrodynamic variables. The glacial sequences in the core contain six ice-rafting events (IRE). They are comparable with the North Atlantic Heinrich Events, although their characteristics show dominant influences from the proximal British-Irish Ice Sheet (BIIS). These IRE have a low magnetic susceptibility and are deposited during two or three ice-rafting pulses. The record of ice-rafting suggests a millennial-scaled BIIS destabilisation and confirms the start of a final retreat about 25 ka ago. Additionally, the glacial sequence corresponds to a muddy contourite, influenced by bottom-current strength variations during interstadials, possibly triggered by sporadic reintroductions of Mediterranean Outflow Water in a glacial North Atlantic Ocean. The interglacial sequence features an 11-m thick deep-water massive sand unit, probably deposited under a high-energy bottom-current regime.
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Van Rooij D., Blamart D., Richter T., Wheeler A., Kozachenko M., Henriet J.-P. (2007). Quaternary sediment dynamics in the Belgica mound province, Porcupine Seabight: ice-rafting events and contour current processes. International Journal Of Earth Sciences, 96(1), 121-140. Publisher's official version : https://doi.org/10.1007/s00531-006-0086-6 , Open Access version : https://archimer.ifremer.fr/doc/00233/34438/