Strike-slip tectonics in the SW Barents Sea during North Atlantic rifting (Swaen Graben, Northern Norway)

• Published in: Tectonics
• Main Authors: Omosanya, Kamaldeen, Zervas, Ioannis, Mattos, Nathalia, Alves, Tiago, Johansen, Stale, Marfo, George
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2017
• Subjects: Barents Sea; Norway; North Atlantic; Northern Norway
• Online Access: https://orca.cardiff.ac.uk/id/eprint/105524/; https://doi.org/10.1002/2017TC004635; https://orca.cardiff.ac.uk/id/eprint/105524/1/Alves_Tectonics_2017_accepted.pdf

This study uses high quality, three-dimensional [3-D] seismic data to investigate the occurrence of strike-slip faults in the Swaen Graben, SW Barents Sea. The Swaen Graben is divided into two principal sub-basins:- SSB1 and SSB2. The along-strike and along–dip displacement variations and scale relationships are analyzed for forty-two [42] faults. The displacement profiles for these faults are complex in the Swaen Graben, showing clear evidence for polycyclic fault growth and marked syn-sedimentary activity. The observed variations in the displacement profiles indicate complex along-strike segmentation, linkage and mechanical interactions at distinct structural levels. Along-dip displacement minima indicate fault reactivation by dip-linkage. Importantly, geometric evidence for strike-slip faulting in the Swaen graben includes the presence of extensional horsetail splay faults, positive flower structures and minor transfer faults. This study shows that the faults in the Swaen Graben developed under extensional regimes during Late Jurassic to Early Cretaceous rifting and were reactivated by regional stresses during the Late Cretaceous. The two principal strike-slip faults in the Swaen Graben reveal sinistral movement and are linked at a shallow depth by minor transfer faults at a relay zone. Our work further demonstrates the occurrence of Late Mesozoic strike-slip movements in the SW Barents Sea, which were induced by regional tectonics, halokinesis and fault block rotation. Importantly, strike-slip faulting in the region extends perhaps into the Cenozoic interacting with extension during the North Atlantic rifting.