EGU2020-17586, updated on 14 Dec 2020
https://doi.org/10.5194/egusphere-egu2020-17586
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Relationship between salt and crustal tectonics in the Sørvestsnaget Basin, SW Barents Sea

Gaia Travan1, Benjamin Bellwald2, Sverre Planke2,3,4, Virginie Gaullier1, Dwarika Maharjan2, and Bruno C. Vendeville1
Gaia Travan et al.
  • 1Univ. Lille, CNRS, Univ. Littoral Côte d’Opale, UMR 8187, LOG, Laboratoire d’Océanologie et de Géosciences, F59000 Lille, France (gaia.travan@univ-lille.fr)
  • 2Volcanic Basin Petroleum Research (VBPR), Norway
  • 3Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Norway
  • 4Research Centre for Arctic Petroleum Exploration (ArcEx), The Arctic University of Norway

The geology of the Barents Sea has been widely studied because of the interest for hydrocarbon exploration. Our study focuses on the SW Barents Sea, on the western side of the Senja Ridge in the Sørvestsnagets Basin, which is still a less deciphered area. Located at the limit of the continental shelf, this deep Cretaceous basin is characterized by a several-kilometer-thick sequence of Cenozoic sediments locally influenced by salt structures. Because of the peculiar rheological characteristics of salt, the deposition of evaporites during Permo-Carboniferous times still represents a key aspect to deeply understand the geological setting because salt tectonics considerably affects the brittle sedimentary cover.

5,500 km2 of high-quality 3D seismic data, integrated with potential field data and existing wells, led to the interpretation of the main horizons and unconformities in the sedimentary sequence, with focus on the salt structures.

The top of the salt is characterized by a strong positive-amplitude reflection in the seismic data, and has been interpreted with a line spacing of 100 m. Subsequent gridding of the interpreted horizon to a bin size of 12.5 m highlights that the geomorphology for the top of the three salt structures is particularly complex, with presence of salt horns and development of minibasins above the salt. Integration of potential field data shows a strong correlation between salt structures and low values in Bouguer-Gravity anomalies. Different families of faults related to salt and to crustal tectonics have been mapped, and strong seismic anomalies related to faults above the salt structures are identified at multiple stratigraphic levels. Part of these faults have been active until 20 000 years ago, and are rarely active at present day.

The three salt structures interpreted on the western side of the Senja Ridge have a total extent of around 800 km2 and are mainly the consequence of different pulses of reactive diapirism, due to several diachronous rifting events during the opening of the Barents Sea. After the opening of the Sørvestsnagets Basin, salt tectonics continued and was influenced by crustal movements and glacial sedimentation and erosion in this pull-apart basin setting.

The presence of the strong seismic anomalies above the salt structures is interpreted as gas accumulations, which makes this topic of particular interest for the future development of the oil and gas industry of the SW Barents Sea.

How to cite: Travan, G., Bellwald, B., Planke, S., Gaullier, V., Maharjan, D., and Vendeville, B. C.: Relationship between salt and crustal tectonics in the Sørvestsnaget Basin, SW Barents Sea, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17586, https://doi.org/10.5194/egusphere-egu2020-17586, 2020

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