Institute of the Earth's Crust SB Russian Academy of Sciences Irkutsk 664033 Russia;
Vinogradov Institute of Geochemistry SB Russian Academy of Sciences Irkutsk 664033 Russia;
Irkutsk State University Irkutsk 664033 Russia;
Institute of Archaeology and Ethnography SB Russian Academy of Sciences Novosibirsk 630090 Russia;