1. Geological Survey of Denmark and Greenland; Øster Voldgade 10 1350 København K Denmark
2. Department of Geosciences and Natural Resource Management; Geology Section; University of Copenhagen; Øster Voldgade 10 1350 København K Denmark
3. Center for Past Climate Studies; Department of Geoscience; Aarhus University; Høegh-Guldbergs Gade 2 8000 Aarhus C Denmark
4. Geological Survey of Sweden; Villavägen 18 Uppsala Sweden
5. Geophysics; University of Hamburg; Bundesstr. 55 D-20146 Hamburg Germany