A multi-disciplinary study of Late-Caenozoic sedimentary processes on the eastern slope ofthe Porcupine Seabight, southwest of Ireland

International audienceStudies of deepwater contourite and turbidite systems necessitate a multi-disciplinary approach, because these deposits can not be interpreted unambiguously. A more challenging problem is the discrimination of both processes in mixed systems. Such an interplay of sedimentation processes is present on the eastern slope of the Porcupine Seabight. Within the Belgica mound province, the geometry of the most recent sedimentary unit is affected by changes in the vigour of bottom currents, due to the presence of the mounds and steep slopes in the palaeotopography of the underlying unit. There seems to be a complex coupling between the glacial/interglacial cycles and the deposition of muddy and sandy contourites. Near the flanks of the mounds, turbidite channels are present. South of the Belgica mounds, the slope becomes more incised with channels. Some of them are relatively short and dominated by mass-wasting processes, but some features indicate sediment shaping by downslope running currents. The Gollum Channels, on the contrary, yield spectacularly thick turbidite deposits, but coring has indicated it hasn't been active since the Holocene