1. Leibniz Institute for Baltic Sea Research Warnemünde; Seestrasse 15 Rostock 18119 Germany
2. Department of Geosciences and Natural Resource Management; University of Copenhagen; Øster Voldgade 10 Copenhagen 1350 Denmark
3. Department of Earth Sciences; Uppsala University; Villavägen 16 Uppsala 75236 Sweden
4. Geological Survey of Finland; PL 96 (Betonimiehenkuja 4) Espoo 02151 Finland
5. Department of Marine Geology; Geological Survey of Sweden; Box 670 Uppsala 751 28 Sweden
6. Geological Survey of Denmark and Greenland; Øster Voldgade 10 Copenhagen 1350 Denmark
7. Department of Earth Sciences; Vrije Universiteit Amsterdam; De Boelelaan 1085 Amsterdam 1081HV the Netherlands
8. University of Cologne; Zülpicher Strasse 49a Cologne 50674 Germany