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Presentation at the conference "Vinterkonferansen", 7. - 9.01.19, Bergen, arranged by NGF (Norsk Geologisk forening). https://www.geologi.no/konferanser/vinterkonferanser/item/947-vk19.

Accepted manuscript version. Published version available at https://doi.org/10.1016/j.jog.2018.03.004. Accepted manuscript version, licensed CC BY-NC-ND 4.0. The evolution of the northwestern Barents Sea continental margin, part of a NW-SE trending mega shear zone, has been reconstructed in order to quantify the sedimentation and erosion affecting this area during and after its formation in the Paleogene–Neogene. This development was closely related to the sea-floor opening of the Norwegian-Greenland Sea. Our study incorporated 2D seismic data, well data, and information from shallow cores. During the Paleocene–Eocene, the northwesternmost Barents Sea margin was subjected to compression-transpression that led to the development of the West Spitsbergen Fold-Thrust Belt (WSFTB) and largely affected the northern part of the study area. To the south, the Vestbakken volcanic province developed in a pull-apart setting. A transition zone separates these two areas marked by a basin morphology becoming more pronounced to the south suggesting increasing subsidence and extension. Subsequently, during the Oligocene, extension and sea-floor spreading were initiated along the whole margin, resulting in the opening of the Fram Strait between Spitsbergen and NE Greenland in the Miocene. During the Paleocene, the Stappen High and a part of the NE Greenland shelf sourced sediments into the newly developing basins. The southwestern part of the WSFTB, the Stappen High, and part of the NE Greenland margin are interpreted as the main sediment source areas in the Eocene. During the Oligocene and Neogene, a larger part of the northwestern Barents Sea shelf is interpreted to have acted as source area including the Edgeøya platform. As a result of this development, the wider Barents Sea shelf itself is inferred to have been a lowland prior to the northern hemisphere glaciations. We found that the average sedimentation rate for the Paleogene–Neogene at the northwestern Barents Sea margin is about 0.034 m/k.y. This number is in agreement with the sedimentation rate reported from present-day fluvial systems and modern rates coastal erosion. By using a mass-balance approach, we have also estimated the average net erosion and erosion rate for the Paleogene–Neogene period to be ∼2440 m and 0.038 m/k.y, respectively. This erosion rate is two times higher compared to the southwestern Barents Sea margin, probably reflecting erosion of a more tectonically active northwestern margin. Thus, for the western Barents Sea margin, a general increasing trend of pre-glacial erosion northwards can be inferred. This study also suggests that more than half of the Cenozoic erosion affecting the studied part of the northwestern Barents Sea were of pre-glacial origin.

The papers 1, 2 and 3 are not available in Munin.Paper 1: Lasabuda, A., Laberg, J. S., Knutsen, S.-M., Høgseth, G. Early to middle Cenozoic paleoenvironment and sediment yield of the southwestern Barents Sea continental margin: Insights from a regional mass-balance approach. (Manuscript). Accepted manuscript version available in Marine and Petroleum Geology, June 2018 Paper 2: Lasabuda, A., Laberg, J. S., Knutsen, S.-M, Safronova, P. A. Cenozoic tectonostratigraphy and pre-glacial erosion: A mass-balance study of the northwestern Barents Sea margin, Norwegian Arctic. (Manuscript). Accepted manuscript version available in Journal of Geodynamics, Special Arctic Issue 2018. Paper 3: Lasabuda, A., Geissler, W. H., Laberg, J. S., Knutsen, S.-M, Rydningen, T. A., Berglar, K. Late Cenozoic glacial sediment input to the Arctic Ocean – quantifying the contribution from the Barents Sea. (Manuscript). Final version with altered title, published in Geochemistry, Geophysics, Geosystems, 19(12), 4876-4903, is available at https://doi.org/10.1029/2018GC007882 The Barents Sea shelf has been experienced extensive uplift and erosion in the Cenozoic. However, the pre-glacial erosion has been so far less constrained in comparison to the glacial erosion. This paper aims to better understand the early–middle Cenozoic erosion in the western Barents Sea and the late Cenozoic erosion in the northern Barents Sea by using the mass-balance approach. The study utilizes seismic and well data to map the Cenozoic sediments and to estimate their volumes. The paleoenvironmental reconstruction is used to delineate the size of the likely source areas. From this, the average erosion and erosion rates are estimated. It is important to quantify the erosion as an effort to lower the risk in petroleum exploration in the Barents Sea. This study is also essential to understand the sedimentation pattern and their relation to the tectonic development. The paper suggests an N-S trending of uplift and erosion in the early–middle Cenozoic and E-W trending of uplift and erosion in the late Cenozoic. For the first time, the glacial erosion is estimated in the northeastern Svalbard/northern Barents Sea continental margin, which reflects the sediment input to the Arctic Ocean. The average erosion rates show one order of magnitude lower than the glacial erosion rates. The estimated numbers from this thesis are compared to the other high-latitude margins and in agreement with present-day systems.