1. Globe Institute, University of Copenhagen, Copenhagen K, Denmark
2. Department of Geoscience, Aarhus University, Aarhus C, Denmark
3. Department of Geology, Cal Poly Humboldt, Arcata, California, USA
4. Environmental Archaeology and Materials Science, National Museum of Denmark, Lyngby, Denmark
5. Department of Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen K, Denmark
6. DTU–Space, Technical University of Denmark, Kongens Lyngby, Denmark
7. Department of Physics and Astronomy, Aarhus University, Aarhus C, Denmark