1. Department of Marine Geology; Leibniz Institute for Baltic Sea Research; Rostock Germany
2. Department of Earth Science and Bjerknes Centre for Climate Research; University of Bergen; Allégaten 41 Bergen 5055 Norway
3. Geological Survey of Denmark and Greenland; Øster Voldgade 10 Copenhagen DK-1350 Denmark
4. Faculty of Earth and Life Sciences; Vrije Universiteit; de Boelelaan 1085 Amsterdam 1081HV The Netherlands