caa a22 4500 445364904 CHVBK 20180317142927.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11001-011-9127-z doi (NATIONALLICENCE)springer-10.1007/s11001-011-9127-z The Cenozoic western Svalbard margin: sediment geometry and sedimentary processes in an area of ultraslow oceanic spreading [Elektronische Daten] [Ingrid Amundsen, Maria Blinova, Berit Hjelstuen, Rolf Mjelde, Haflidi Haflidason] The northeastern high-latitude North Atlantic is characterised by the Bellsund and Isfjorden fans on the continental slope off west Svalbard, the asymmetrical ultraslow Knipovich spreading ridge and a 1,000m deep rift valley. Recently collected multichannel seismic profiles and bathymetric records now provide a more complete picture of sedimentary processes and depositional environments within this region. Both downslope and alongslope sedimentary processes are identified in the study area. Turbidity currents and deposition of glacigenic debris flows are the dominating downslope processes, whereas mass failures, which are a common process on glaciated margins, appear to have been less significant. The slide debrite observed on the Bellsund Fan is most likely related to a 2.5-1.7Ma old failure on the northwestern Barents Sea margin. The seismic records further reveal that alongslope current processes played a major role in shaping the sediment packages in the study area. Within the Knipovich rift valley and at the western rift flank accumulations as thick as 950-1,000m are deposited. We note that oceanic basement is locally exposed within the rift valley, and that seismostratigraphic relationships indicate that fault activity along the eastern rift flank lasted until at least as recently as 1.5Ma. A purely hemipelagic origin of the sediments in the rift valley and on the western rift flank is unlikely. We suggest that these sediments, partly, have been sourced from the western Svalbard—northwestern Barents Sea margin and into the Knipovich Ridge rift valley before continuous spreading and tectonic activity caused the sediments to be transported out of the valley and westward. The Author(s), 2011 Svalbard margin nationallicence Ultraslow spreading ridge nationallicence Trough mouth fans nationallicence Glaciations nationallicence Sedimentary processes nationallicence Amundsen Ingrid Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut Blinova Maria Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut Hjelstuen Berit Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut Mjelde Rolf Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut Haflidason Haflidi Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut Marine Geophysical Research Springer Netherlands 32/4(2011-12-01), 441-453 0025-3235 32:4<441 2011 32 11001 https://doi.org/10.1007/s11001-011-9127-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11001-011-9127-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Amundsen Ingrid Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Blinova Maria Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Hjelstuen Berit Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Mjelde Rolf Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Haflidason Haflidi Department of Earth Science, University of Bergen, Allegt 41, 5007, Bergen, Norway aut NATIONALLICENCE 773 0- Marine Geophysical Research Springer Netherlands 32/4(2011-12-01), 441-453 0025-3235 32:4<441 2011 32 11001 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer