The role of core complexes in the tectonic evolution of SW Norway and the northern North Sea

In large parts of the Norwegian continental shelf, core complexes played an important role for passive margin evolution and the formation of long-lived structural highs. Yet, their role has not been clarified south of the Western Gneiss Region.

In this project we are going to investigate the role of core-complex formation for the tectonic evolution of SW Norway and the northern North Sea. To do this, we will combine field mapping, structural analysis and integrated geo-thermochronology of dome-shaped basement culminations in the area between Sognefjorden and Hardangerfjorden. We will apply a suite of established as well as advanced geo-thermochronological methods (e.g. zircon double dating) on samples from the pre-Caledonian basement and its metamorphic cover, Devonian sedimentary basin substrate as well as crystalline rocks from structural highs in the North Sea rift. This will allow us to establish the exhumation history of different tectonic units in SW Norway, including a source-to-sink perspective.

The results from this study will help us to understand how inherited, dome-shaped basement structures influenced fault evolution, sedimentary basin formation and the distribution of petroleum resources in the northern North Sea.

Fig. 1: View from Mt. Ulriken towards the West over the city of Bergen, showing the Øygarden Complex, one of the field areas of this study. The contact between the dome-shaped basement window and the metamorphic cover rocks of the Minor Bergen Arc is prominently marked by the mountains on the other side of the city.