1. Geological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen K, Denmark
2. Lithospheric Organic Carbon (LOC) Group, Department of Geoscience, Aarhus University, Høegh Guldbergs Gade 2, 8000 Aarhus, Denmark
3. Globe Institute, University of Copenhagen, Øster Voldgade 5–7, 1350 Copenhagen K, Denmark
4. Alfred Wegener Institute, Am Handelshafen, 27570 Bremerhaven, Germany