Title The formation and evolution of an isolated submarine valley in the North Channel, Irish Sea; an investigation of Beaufort's Dyke
Author Callaway, A.; Quinn, R.; Brown, C.J.; Service, M.; Long, D.; Benetti, S.
Author Affil Callaway, A., University of Ulster, Centre for Coastal and Marine Research, Coleraine, United Kingdom. Other: Agri-Food and Biosciences Institute, United Kingdom; British Geological Survey, United Kingdom
Source JQS. Journal of Quaternary Science, 26(4), p.362-373, . Publisher: John Wiley and Sons for the Quaternary Research Association, Chichester, United Kingdom. ISSN: 0267- 8179
Publication Date May 2011
Notes In English. 69 refs. GeoRef Acc. No: 310651
Index Terms erosion; profiles; geophysical surveys; glacial erosion; marine deposits; ocean bottom; Pleistocene; Quaternary deposits; sediments; seismic surveys; surveys; Irish Sea; Atlantic Ocean; bathymetry; Beaufort's Dyke; bedforms; Cenozoic; continental shelf; geophysical methods; geophysical profiles; marine sediments; North Atlantic; North Channel; ocean floors; paleoenvironment; Quaternary; seismic methods; seismic profiles; subglacial environment
Abstract Beaufort's Dyke is a submarine depression located in the North Channel of the Irish Sea. With a maximum depth of 312 m, the dyke is one of the deepest areas within the European continental shelf. Integration and interpretation of 450 km of sparker seismic data and full-coverage bathymetric data derived from multi-beam echo sounder surveys allow for the investigation of the formation processes of Beaufort's Dyke and the evolution of geomorphological features within it. The dyke, formed by composite subglacial processes dominated by subglacial meltwater discharge, is interpreted as a tunnel valley. The regional isolation of Beaufort's Dyke may be explained by the bounding of the North Channel by the bedrock masses of Ireland and Scotland, coupled with the exploitation of structural weakness along a fault plane and presence of halite in the eroded substrate enhancing the erosive potential of the overlying glacier. Beaufort's Dyke has probably been maintained as an open feature by strong rectilinear tidal currents. The morphology of lunate sediment waves and a large parabolic bedform towards the south of the dyke contradict the observed dominant S-N mean hydrodynamic flow recorded within the North Channel, suggesting an alternative hydrodynamic regime either within the dyke or during bedform creation. Abstract Copyright (2010), John Wiley & Sons, Ltd.
URL http://hdl.handle.net/10.1002/jqs.1460
Publication Type journal article
Record ID 66000022