[1] Norwegian Acad Sci & Letters, Ctr Adv Study, N-0271 Oslo, Norway
[2] Univ Oslo, Ctr Phys Geol Proc PCP, NO-0316 Oslo, Norway
[3] Geol Survey Norway, Geodynam, N-7491 Trondheim, Norway
[4] Univ Witwatersrand, Sch Geosci, ZA-2050 Johannesburg, South Africa
[5] Univ Michigan, Dept Earth & Environm Sci, Ann Arbor, MI 48109 USA
[6] Univ Tartu, Dept Geol, EE-50411 Tartu, Estonia
[7] Dept Earth Sci, Oxford OX1 3AN, England
[8] GFZ German Res Ctr Geosci, Helmholtz Ctr Potsdam, Sect 2 5, D-14467 Potsdam, Germany
[9] Univ Western Australia, Sch Earth & Environm, Crawley, WA 6009, Australia
[10] Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA
[11] Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada
[12] Nat Hist Museum, Dept Earth Sci, London SW7 5BD, England