1. Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen C, Denmark
2. Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
3. Department of Earth Sciences, Università di Pisa, 56126 Pisa, Italy