COLD PASSIVE CONTINENTAL MARGINS: THE ENIGMATIC TOPOGRAPHY IN WESTERN SCANDINAVIA

Substantial controversy surrounds the origin and recent evolution of high topography along the passive continental margins that fringe the North Atlantic – particularly for the western Scandinavian margin. An important aspect of this controversy relates to the formation of the margin’s characteristic landscape, with deep fjords and intervening high-elevation landscapes of relatively low relief.

These high-elevation low-relief landscapes have traditionally been interpreted as remnants of a Mesozoic peneplain, elevated and dissected during several phases of uplift in the Paleogene and especially the Neogene. In this case, the topography in Scandinavia is an old dissected landscape that predates the younger mountains.

Here we focus on an alternative hypothesis for the formation of the high topography and the characteristic landscape elements in western Scandinavia. In essence, this hypothesis suggests that the high topography in western Scandinavia predates the Cenozoic and that the landscape has been shaped continuously, although with renewed intensity in the Quaternary. In this case the topography in Scandinavia represents an in-situ shaped landscape that postdates the older mountains.

In this contribution we evaluate offshore sediment volumes and cosmogenic nuclide data against quantitative estimates of onshore erosion and results from numerical landscape evolution modeling, in order to assess the recent Quaternary landscape evolution in Scandinavia and the effects glaciations have had on the pre-Quaternary topography.