The acoustic and sedimentological face of the sediments surrounding the Belgica Mounds Province
Van Rooij, D.; Kozachenko, M.; Blamart, D.; Lekens, W.; Wheeler, A.; Henriet, J.-P. (2000). The acoustic and sedimentological face of the sediments surrounding the Belgica Mounds Province. Eos, Trans. (Wash. D.C.) 81(48): F638 In: Eos, Transactions, American Geophysical Union. American Geophysical Union: Washington. ISSN 0096-3941; e-ISSN 2324-9250, more |
| Available in | Authors | | Document type: Summary
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| Authors | | Top | - Van Rooij, D., more
- Kozachenko, M.
- Blamart, D.
| - Lekens, W.
- Wheeler, A., more
- Henriet, J.-P., more
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| Abstract | Sidescan sonar imagery acquired during the TTR-7 cruise In July 1997 were the first to reveal the presence of a current swept seafloor between 600 and 1200 m on the upper slope of the Eastern Porcupine Seabight (SW off Ireland). Most of these features (parallel grooves, sand sheets and sand waves) were found within the vicinity of coral banks, called the Belgica Mound province. Current speed was estimated up to 100 cm/s flowing northward. The depth interval in which these currents occur coincides with the presence of a core of Mediterranean Outflow Water. Most likely the sharp density contrast between the MOW and the overlying European North Atlantic Water is thought to locally enhance the effects of this contour current. In this poster presentation we illustrate and discuss the seismic and sedimentological facies of the drift body surrounding the Belgica Mound province. Therefore, airgun-array and sparker seismic profiles (respectively low- and very high-resolution) are used. We clearly observe the influence of the mounds on the bottom current regime. At present, it is clear that the present-day and past current regime is by far more complicated then generally assumed. A set of giant piston cores taken within the framework of the ENAM2 and IMAGES programmes were analysed for their magnetic susceptibility, grainsize distribution, foraminifer and IRD content within the fraction superior to 150 µm, We also investigated the abundance of planktonic foraminifers (e.g. N. pachyderma s.) and the epibenthic foraminifers U. Mediterranea and P. ariminensis. The results suggest the presence of intensified bottom currents, within the MOW core, during climatic warmer periods. Although the work in this region is within an early stage of investigation, we might add this region to the large inventory of sediment drifts and contourites. |
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