Late Pleistocene sedimentation on the Norwegian continental slope between 67° and 71°N

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The northern Norwegian continental margin between 67° and 71°N comprises the gentle slope off the Barents Sea, the relatively steep Lofoten Islands slope, and the step-like slope of the Voring Plateau. During the late Pleistocene, these slopes received large amounts of terrigenous sediments from an extensively glaciated Norwegian continental margin. Through the analyses of 17 gravity cores, high-resolution (3.5 kHz) and airgun seismic profiles, and Sea-Beam bathymetric data, we have examined the late Pleistocene sedimentation pattern of this region. Eight sedimentary facies from the gravity core analysis and seven types of 3.5 kHz echo characters indicate that the slopes were moulded by hemipelagic sedimentation commonly associated with iceberg rafting, slope failure (slump/slide and debris flow), turbidity currents, downslope bottom currents, and contour-following bottom currents. Ice-rafted debris was dispersed over a broad area, including the lower slopes off the Barents Sea and the Lofoten Islands, and the Voring Plateau and its outer slope. Slope failures prevailed on the Lofoten Islands and Voring Plateau slopes where the broad glacial margin directly released unsorted glacial sediments during glacial periods. On the Barents Sea slope, glacial and reworked shelf sediments were supplied by underflows which were probably caused by cooling of surface shelf water during glacial periods; on the upper slope sediments were further transported by turbidity currents and slope-crossing bottom currents which excavated numerous small-scale channels. There are indications of deep-sea contour currents at the base of slope and the upper slope off the Barents Sea, and on the Voring Plateau. These currents probably resulted from water exchange between the Norwegian-Greenland Sea and the North Atlantic Ocean during interglacial periods.