1. Department of Earth Sciences; Uppsala University; Villavägen 16 752 36 Uppsala Sweden
2. Earth Science Institute; Slovak Academy of Sciences; Dúbravská 9 PO Box 106 840 05 Bratislava Slovak Republic
3. Faculty of Geology, Geophysics and Environmental Protection; AGH - University of Science and Technology; Mickiewicza 30 30-059 Kraków Poland
4. University of Bonn; Steinmann-Institut; Poppelsdorfer Schloss D-53115 Bonn Germany
5. Institute of Chemistry; Slovak Academy of Sciences; Dúbravská 9 840 05 Bratislava Slovak Republic