Tanja Denager, University of Copenhagen, Department of Geosciences and Natural Resource Management, Copenhagen K, Denmark, Torben Obel Sonnenborg, Geological Survey of Denmark and Greenland, København K, Denmark, Majken Looms, University of Copenhagen, Department of Geosciences and Natural Resource Management, Copenhagen, Denmark and Karsten H. Jensen, Univ Copenhagen, Department of Geosciences and Natural Resource Management, Copenhagen K, Denmark