1. Institute of the Earth’s Crust, SB RAS, 128 Lermontov St., 640033 Irkutsk, Russia
2. Chemistry Department, Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia
3. Pedagogical Institute, Irkutsk State University, 1 K. Marx St., 664003 Irkutsk, Russia
4. Vinogradov Institute of Geochemistry, SB RAS, 1 A. Favorsky St., 664033 Irkutsk, Russia