[1] CNRS, UMR 6635, CEREGE, F-13545 Aix En Provence 4, France
[2] Rice Univ, Dept Earth Sci, Keith Wiess Geol Labs, Houston, TX 77005 USA
[3] Rutgers State Univ, Wright Labs, Dept Geol Sci, Piscataway, NJ 08854 USA
[4] Univ Texas Austin, Inst Geophys, John A & Katherine G Jackson Sch Geosci, Austin, TX 78758 USA