1. Institute of Earth Sciences, Saint Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia
2. Geological Institute of Russian Academy of Sciences, Pyzhevski Lane 7, Moscow 119017, Russia
3. Diamond and Precious Metal Geology Institute, Siberian Branch, Russian Academy of Sciences, Lenin av. 39, Yakutsk 677000, Russia
4. Department of Geological Sciences, Jackson School of Geoscience, University of Texas at Austin, Austin, TX 78712-1692, USA