Gravity flow deposits in the deep Rockall Trough, Northeast Atlantic

Aggeliki Georgiopoulou, Sara Benetti, Patrick M. Shannon, Peter D.W. Haughton, Stephen McCarron

Research output: Chapter in Book/Conference proceeding with ISSN or ISBNConference contribution with ISSN or ISBN

Abstract

The north-western margin of the Irish Rockall Trough in the Northeast Atlantic is dominated by the scarps of the Rockall Bank Mass Flow (RBMF) which extends towards the centre of the Rockall Trough, whereas the eastern margin is incised by numerous canyons that have no obvious associated fans at the foot of the slope. Terminal lobes associated with the glaciogenic Donegal-Barra Fan extend into the Rockall Trough from the northeast, whereas in the southwest the seafloor is dominated by the Feni Drift, a giant contourite drift formed by ocean bottom currents which was truncated by the sidewalls and depositional lobes of the RBMF. In June 2010 the RV Celtic Explorer cruise CE10008 collected the first comprehensive set of piston cores from the Irish sector of the deep Rockall Trough. Here we report on a sub-set of those cores recovered from across and beyond the bathymetric expression of the RBMF eastern outer limit in order to determine whether gravity flows were released during this event and whether they have traversed across the basin. The cores, taken in water depths of nearly 3,000 m, reveal that significant coarse sediment (up to coarse sand) was emplaced on the deep basin floor by both turbidity currents and bottom currents. We identify several discrete turbidite sand and silt deposits with geochemical signatures that point to different source areas. The youngest two appear to have been generated from the area occupied by the RBMF to the west during the Holocene. The remaining turbidite beds came from an easterly or northeasterly source and tie back to the Donegal-Barra Fan and are probably glacially related. Between the two periods we find a thick (>1.5 m) contouritic sand, possibly formed by bottom current reworking of the Feni Drift.

Original languageEnglish
Title of host publicationSubmarine Mass Movements and Their Consequences - 5th International Symposium
PublisherKluwer Academic Publishers
Pages695-707
Number of pages13
ISBN (Print)9789400721616
DOIs
Publication statusPublished - 1 Jan 2012
Event5th International Symposium on Submarine Mass Movements and Their Consequences - Kyoto, Japan
Duration: 24 Oct 201126 Oct 2011

Publication series

NameSubmarine Mass Movements and Their Consequences - 5th International Symposium

Conference

Conference5th International Symposium on Submarine Mass Movements and Their Consequences
CountryJapan
CityKyoto
Period24/10/1126/10/11

Keywords

  • Contourite
  • Donegal-barra fan
  • Provenance
  • Rockall bank mass flow
  • Turbidite

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  • Cite this

    Georgiopoulou, A., Benetti, S., Shannon, P. M., Haughton, P. D. W., & McCarron, S. (2012). Gravity flow deposits in the deep Rockall Trough, Northeast Atlantic. In Submarine Mass Movements and Their Consequences - 5th International Symposium (pp. 695-707). (Submarine Mass Movements and Their Consequences - 5th International Symposium). Kluwer Academic Publishers. https://doi.org/10.1007/978-94-007-2162-3_62