1. Geological Survey of Denmark and Greenland, Oster Voldgade 10, DK-1350 Copenhagen K, Denmark
2. Federal Institute for Geosciences and Natural Resources, Stilleweg 2, 30459 Hannover, Germany
3. British Geological Survey, Lyell Centre, Edinburgh EH14 4AP, UK
4. Geological Survey of Slovenia, Dimičeva ulica 14, 1000 Ljubljana, Slovenia