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Processes of sedimentation in Gollum Channel, Porcupine Seabight: submersible observations and sediment analyses

Published online by Cambridge University Press:  03 November 2011

Alexander W. Tudhope  and
Terence P. Scoffin
Alexander W. Tudhope
Affiliation:
Department of Geology & Geophysics. Edinburgh University, West Mains Road. Edinburgh EH9 3JW, Scotland, UK.
Terence P. Scoffin
Affiliation:
Department of Geology & Geophysics. Edinburgh University, West Mains Road. Edinburgh EH9 3JW, Scotland, UK.
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Abstract

Manned submersible dives were conducted in the submarine canyon channel system of Porcupine Seabight, NE Atlantic Ocean. Visual observations were made, and sediment samples collected and analysed to elucidate the nature of the sedimentary regime. In the upper part of the canyon (480-940 m water depth) sediments consisted of a mixture of terrigenous quartz rich silts and sands, skeletal carbonate of benthonic and planktonic origin and minor clay minerals and authigenic dolomite. There were localised Lophelia pertusa coral thickets on both the flanks and floor of the canyon. Sedimentary structures and physical measurements revealed there to be active transport of sediments in the canyon down to a depth of at least 940 m, effected by (?tidal) reversing currents and bioturbation. In these parts of the canyon, deposits around glacial dropstones and coral thickets indicate that there has been a maximum of 0-1 m of net sediment accumulation since the last glacial period. At 3000 m water depth, in the channel system, the sediments were fine calcareous ooze with a drape (up to 0-3 m thick) of flocculant phytoplankton detritus. At these depths, there was no evidence for present-day sediment resuspension by currents.

Keywords

Submarine canyondeep sea sedimentationdeep sea coralflocculant phytoplankton detrites.
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 86 , Issue 1 , 1995 , pp. 49 - 55
Copyright
Copyright © Royal Society of Edinburgh 1995

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References

Auffret, G.-A., Auzende, J.-M., Cousin, M., Coutelle, A., Dobson, M., Geoghegan, M., Masson, D., Rolet, J. & Vaillent, P. 1987. Géologie des escarpements de Porcupine et de Goban (NE Altantique). Résultats de la campagne de plongée CYAPORC. C R ACAD SCI (PARIS) 304, 1003-8.Google Scholar
Kenyon, N. H., Belderson, R. H. & Stride, A. H. 1978. Channels, canyons and slump folds on the continental slope between South-West Ireland and Spain. OCEANOL ACTA 1, 369–80.Google Scholar
Lampitt, R. S. 1985. Evidence for the seasonal deposition of detritus to the deep-sea floor and its subsequent resuspension. DEEPSEA RES 32, 885–97.Google Scholar
Masson, D. G., Dobson, M. R., Auzende, J.-M., Cousin, M., Coutelle, A., Rolet, J. & Vaillant, P. 1989. Geology of Porcupine Bank and Goban Spur, northeastern Atlantic. Preliminary results of the Cyaporc submersible cruise. MAR GEOL 87, 105–19.CrossRefGoogle Scholar
Naylor, D. & Shannon, P. M. 1982. The geology of offshore Ireland and West Britain. London: Graham & Trotman.CrossRefGoogle Scholar
Roberts, D. G., Masson, D. G., Montadert, L. & de Charpal, O. 1981. Continental margin from the Porcupine Seabight to the American marginal basin. In Illing, L. V. & Hobson, G. D. (eds) Petroleum geology of the Continental Shelf of North-West Europe, 455–73. London: Heyden & Son Ltd.Google Scholar
Scoffin, T. P. & Bowes, G. E. 1988. The facies distribution of carbonate sediments on Porcupine Bank, northeast Atlantic. In Nelson, C. S. (ed.) Non-tropical shelf carbonates—modern and ancient. SEDIMENT GEOL 60, 125–34.CrossRefGoogle Scholar
Scoffin, T. P., Alexandersson, E. T., Bowes, G. E., Cloakie, J. J., Farrow, G. E. & Milliman, J. D. 1980. Recent, temperate, subphotic, carbonate sedimentation: Rockall Bank, north-east Atlantic. J SEDIMENT PETROL 50, 331–56.Google Scholar
Shepard, S. P., Marshall, N. F., McLoughlin, P. A. & Sullivan, G. G. 1979. Currents in submarine canyons and other seavallevs. STUD GEOL, AM ASSOC PET GEOL. 8, 179pp.Google Scholar
Stow, D. A. V., Howell, D. G. & Nelson, C. H. 1984. Sedimentary, tectonic & sea-level controls on submarine fans and slope-apron turbidite systems. GEOMAR LETT 3, 57–64.Google Scholar
Stride, A. H., Curray, J. R., Moore, D. G. & Belderson, R. H. 1969. Marine geology of the Atlantic continental margin of Europe. PHILOSOPHICAL TRANS R SOC A264, 31–75.Google Scholar
Tudhope, A. W. & Scoffin, T. P. 1987. A device to deposit tracer sediment evenly on the deep sea bed. J SEDIMENT PETROL 57, 761–2.CrossRefGoogle Scholar
Tyler, P. A. & Zibrowius, H. 1992. Submersible observations of the invertebrate fauna on the continental slope southwest of Ireland (NE Atlantic Ocean). OCEANOL ACTA 15, 211–26.Google Scholar
Vaugelas, J. de 1989. Deep-sea lebensspurren: remarks on some echiuran traces in the Porcupine Seabight, northeast Atlantic. DEEP-SEA RES 36, 975–82.CrossRefGoogle Scholar
Wilson, J. B., 1979a. The distribution of the coral Lophelia pertusa (L.) [L. prolifera (Pallas)] in the north-east Atlantic. J MAR BIOL ASSOC UK 59, 149–64.CrossRefGoogle Scholar
Wilson, J. B., 1979b. “Patch” development of the deep-water coral Lophelia pertusa (L.) on Rockall Bank. J MAR BIOL ASSOC UK 59, 165–78.CrossRefGoogle Scholar
Zibrowius, H. 1980. Les scléractinaires de la Meditérranée et de l'Atlantique nord-oriental. MEM INST OCEANOGR (MONACO) 11, 284pp.Google Scholar