Quaternary denudation of southern Fennoscandia – evidence from the marine realm

Throughout the last 1.1 million years repeated glaciations have modified the southern F ennoscandian landscape and the neighbouring continental shelf into their present form. The glacigenic erosion products derived from the F ennoscandian landmasses were transported to the northern N orth S ea and the SE N ordic S eas continental margin. The prominent sub‐marine N orwegian C hannel trough, along the south coast of N orway, was the main transport route for the erosion products between 1.1 and 0.0 Ma . Most of these erosion products were deposited in the N orth S ea F an, which reaches a maximum thickness of 1500 m and has nearly 40 000 km 3 of sediments. About 90% of the N orth S ea F an sediments have been deposited during the last 500 000 years, in a time period when fast‐moving ice streams occupied the N orwegian C hannel during each glacial stage. Back‐stripping the sediment volumes in the northern N orth S ea and SE N ordic S eas sink areas, including the N orth S ea F an, to their assumed F ennoscandian source area gives an average vertical erosion of 164 m for the 1.1–0.0 Ma time period. The average 1.1–0.0 Ma erosion rate in the F ennoscandian source area is estimated to be 0.15 mm a −1 . We suggest, however, that large variations in erosion rates have existed through time and that the most intense F ennoscandian landscape denudation occurred during the time period of repeated shelf edge ice advances, namely from M arine I sotope S tage 12 ( c . 0.5 Ma ) onwards.