Document of bibliographic reference 199095

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Bibliographic resource

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Book chapters

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AMS

Title

Small mounded contourite drifts associated with deep-water coral banks, Porcupine Seabight, NE Atlantic Ocean

Abstract

Numerous studies on sediment drifts have demonstrated a close interaction between sea-bed morphology, palaeoceanography, sediment supply and climate. Contourites have been reported in areas along continental margins directly influenced by the effect of intensive deepwater currents from the global conveyor belt. In this paper, we report the occurrence of a small-scale confined contourite drift from Porcupine Seabight, SW of Ireland, and its association with a province of coral banks. The Porcupine Basin is a relatively shallow, semi-enclosed basin characterized by the presence of cold-water coral bank provinces. These coral banks are often associated to a strong northward-flowing bottom current, created and steered by a complex interaction of the water mass characteristics, tidal influences and sea-bed morphology. Very highresolution seismic stratigraphy allowed the identification of a small mounded drift, located between a depression created by (1) an irregular palaeotopography caused by a vigorous Late Pliocene erosion event and (2) a north–south alignment of coral banks. Core MD99-2327, taken on the flank of this drift mound, shows the variability of the bottom currents. Sortable silt data show several periods of bottom-current enhancement, which may be linked with warmer periods and an inferred influx of Mediterranean Outflow Water. The glacial part of the core has been interpreted as a muddy contourite with a high content of ice-rafted debris. The lower part of the core is a deep-water massive contourite sand resembling the present-day sea-floor sediments.

Bibliographic citation

Van Rooij, D.; Blamart, D.; Kozachenko, M.; Henriet, J.-P. (2007). Small mounded contourite drifts associated with deep-water coral banks, Porcupine Seabight, NE Atlantic Ocean, in: Viana, A.R. et al. Economic and palaeoceanographic significance of contourite deposits. Geological Society Special Publication, 276: pp. 225-244. https://dx.doi.org/10.1144/GSL.SP.2007.276.01.11

Topic

Marine