1. Department of Earth Sciences Durham University Durham DH1 3LE UK
2. Leibniz Institute for Baltic Sea Research Warnemünde Seestrasse 15 D‐18119 Rostock Germany
3. Department of Geography Durham University Durham DH1 3LE UK
4. Geological Survey of Denmark and Greenland (GEUS) Universitesbyen 81 DK‐8000 Aarhus C Denmark
5. Institute of Geosciences, Department of Geology Kiel University Ludewig‐Meyn Strasse 10 D‐24118 Kiel Germany