| Summary: | International audience The impact of Quaternary glaciations is evidenced worldwide in mountains and may have induced an increase of erosion rates (accelerated erosion). Low-temperature thermochronometry has been extensively used to unravel the complex links between climate and erosion. However, until now, only a limited number of studies detected accelerated erosion that can be interpreted as independent of tectonics and associated with climate change. In these conditions, will low-temperature yield any further advance in our understanding of the interactions between climate change and erosion? Here we discuss about a recent new and high-resolution apatite (U-Th-Sm)/He (AHe) dataset from northern Scandinavia, along the Norwegian Sea continental margin spanning from the Lofoten archipelago to the Tromsø area (68 to 70°N). The region presents dramatic alpine relief. The long-term evolution of the Norwegian margin results from the Caledonian orogeny followed by the Mesozoic rifting and offshore volcanism associated with the North-Atlantic oceanic breakup at c. 50-56 Ma. Bedrock samples were collected at sea-level and additional high-elevation samples were also collected to form elevation-profiles. The results were associated with available apatite fission-track data into inverse thermal modelling using QTQt. The dataset gives an unexpected insight on the extent and character of late Cenozoic erosion in North Scandinavia and the polar regions. A consistent set of AHe ages are younger than any published AFT or AHe ages at surface in Scandinavia (i.e. < 72 Ma). After a long period of tectonic exhumation derived from the Mesozoic rifting, the region underwent a long period with little erosion. Then, the dataset recorded a previously undetected phase of accelerated erosion since the Middle Miocene onwards. The results are interpreted as a consequence of efficient glacial processes, in the context of a gradual cooling of the North Atlantic, and point to Pre-Quaternary ice caps in northern Scandinavia, with a gradual ...
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