Conference Contribution Details
Mandatory Fields
Stapleton, F., Murray, J., Grehan, A., Duffy, G., Williams, M. & Bourillet, J-F.
56th Irish Geological Research Meeting.
A preliminary geological and geophysical description of the Arc Mounds; a cold-water coral carbonate mound region on the southwest Porcupine Bank.
University of Ulster.
Oral Presentation
Optional Fields
Deep-water cold-water coral carbonate mounds occur worldwide and are prominently developed along the European margin. These marine ecosystems are the focus of considerable research efforts at present - in particular in terms of trying to understand the processes controlling their development. This project involves a preliminary description of what have been termed the ĎArc Moundsí, a previously undescribed region situated on the southwestern margin of the Porcupine Bank, which features coral mounds aligned along escarpments. The geological and geomorphological setting of these bioherms was characterised (geophysically) using ship- and ROV-mounted multibeam and subbottom profiler data. Mapping the extent and location of the Arc Mounds has revealed over 40 carbonate buildups, grouped mainly in water depths of between 500m and 1100m. This information was augmented with sedimentolgical and palaeontological data from two piston cores recovered from the summit of a carbonate mound and also from laterally equivalent off-mound facies, on the adjacent seafloor. The differences between the two cores illustrate the role cold water corals play in constructing large 3-dimensional structures on the seabed. A prominent (Chirp-detected) moundbase reflector and sediment recovered from the equivalent depth shows the mounds initially developed on a carbonate hardground. The development of the coral mounds, in this area of the Porcupine Bank, appears to be the result of an interaction between drift deposition and biological growth processes which are both influenced by the local topography and current regime.
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