[1] Imperial Coll London, Dept Earth Sci & Engn, London, England
[2] Albert Ludwigs Univ Freiburg, Inst Geo & Umweltnat Wissensch, Freiburg, Germany
[3] Nat Hist Museum, Imaging & Anal Ctr, London, England
[4] Univ Texas Austin, Jackson Sch Geosci, Inst Geophys, Austin, TX 78712 USA
[5] Univ Texas Austin, Jackson Sch Geosci, Dept Geol Sci, Austin, TX 78712 USA
[6] Univ Montpellier, Geosci Montpellier, Montpellier, France
[7] Univ Hamburg, Inst Geol, Hamburg, Germany
[8] Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Bremerhaven, Germany
[9] Western Univ, Ctr Planetary Sci & Explorat, Dept Earth Sci, London, ON, Canada