International Meeting of Sedimentology - 2017 - Poster
Investigations of a high latitude submarine channel system in the Lofoten basin, polar North Atlantic
(1) Environnements et Paléoenvironnements Océaniques et Continentaux, Université de Bordeaux (France)
(2) Service Hydrographique et Océanographique de la Marine (France)
The Norwegian margin of the Polar North Atlantic comprises the Lofoten Basin Channel. This channel system connects upslope with the Andoya Canyon which is the only canyon to cut back across the continental shelf in this region. Multibeam swath bathymetric data and side-scan sonar data allows the identification of the Lofoten channel described by e.g. Cofaigh et al. (2006). A 5.4 m sedimentary core was collected by the Calypso coreer during the mission SHOM MOCOSED 2014 on the Pourquoi Pas ? A stratigraphic study was realised by comparing several parameters: the magnetic susceptibility and IRD concentration, with six reference cores: JR51-GC03, JR51-GC05, JR51-GC06, GS134-01, GS134-02, and GS134-03, near the study area. Then sedimentary analyzes (rX imaging, XRF ratio microgranulometry) and micropaleontological were compared to determine sedimentary facies. CHIRP seismic profiles were also interpreted.
Those datasets show the influence of turbidity currents in the sedimentation on distal levees of the Lofoten channel and confirms the low activity of turbidity currents since the Holocene. The core, which is 3 km away from the channel, witnesses only the biggest turbidity currents which have occured while the last 50 ka 14C BP, and at least the record of three turbidites since 9 ka cal 14C BP.