1. Institute of Geology v.v.i., The Czech Academy of Sciences, Rozvojová 269, 165 00 Prague, Czech Republic
2. Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic
3. Czech Geological Survey, Geologická 6, 152 00 Prague, Czech Republic
4. Department of Geology, University of the Free State, Bloemfontein 9300, South Africa
5. Department of Applied Geology and Geohazards, Geological Survey of Saxony-Anhalt, Köthener Str. 38, 06118 Halle (Saale), Germany
6. SGS Minerals Services, Lakefield, Ontario KOL 2HO, Canada