The Lofoten contourite drift off Norway

Based on high-resolution and multichannel seismic data, a contourite drift, the Lofoten Drift, has been identified below ca. 1000 m water depth on the continental slope off Norway. The Lofoten Drift has a maximum thickness of about 360 m. Correlation to published seismic stratigraphy implies a Neogene age. The onset of the Lofoten Drift may have been a result of increased circulation within the Norwegian–Greenland Sea, probably controlled by the subsidence of the Greenland–Scotland Ridge. The drift has probably originated from deposition of suspended sediments derived from winnowing of the continental shelf and upper slope. The geometry of the youngest seismic-drift unit, characterised by a maximum thickness at the crest of the mound, indicates that the Lofoten Drift is active at present. The maximum Holocene sedimentation rate is ca. 1 m/ka. The downslope sediment input to the study area was probably relatively low during glacial periods because the Lofoten Islands may have acted as a sediment barrier causing large fluvial and/or glacial drainage systems from central Fennoscandia to be routed south and north of the study area. As a result, alongslope sediment transport has been the main sediment input to this part of the continental slope.