1. Laboratory of Isotope Geochemistry, Geological Institute, Kola Science Centre, Russian Academy of Sciences, 14 Fersman Str., 184200 Apatity, Russia;
2. Polar Marine Geological Exploration Expedition, 24 Pobeda Str., 189510 Lomonosov-St. Petersburg, Russia;
3. Norsk Polarinstitutt, P.O. Box 5072 Majorstua, N-0301 Oslo, Norway.