Permian and Mesozoic extensional faulting within the Caledonides of central south Norway

Palaeomagnetic data from fault rocks along major faults in the Laerdal-Gjen de Fault System cutting the Caledonian structure in the Jotunheimen area of central south Norway reveals a multicomponent remanence pattern. Sample an d site-mean directions from the fault rocks obtained by thermal cleaning de monstrate a simple pattern of normal polarity low blocking components and r everse polarity high-blocking directions. The magnetic signature of the Lae rdal-Gjende Fault System fault rocks is identical to that observed on brecc ias on late faults along the west coast of Norway. Based on available palae omagnetic reference data, we assign ages of mid-late Permian and late Juras sic-early Cretaceous for important phases of faulting and breccia formation along the Laerdal-Gjende Fault System in central south Norway. Structural windows, partly exposing basement along the axis of the Caledonides in sout hern Norway were exhumed by footwall uplift on major faults in the Laerdal- Gjende Fault System. The consanguinity of fault rock data from the Laerdal- Gjende Fault System and fault rocks in western Norway, and comparison with displacement on the offshore continuation of the Laerdal-Gjende Fault Syste m along the Hardangerfjorden Shear Zone, indicate that the main tectonic ev ents responsible for the development of the North Sea basin also significan tly affected the geology of central south Norway.