[1] CNRS, Inst Sci Evolut, UMR 5554, F-34090 Montpellier, France
[2] Fac Sci & Tech St Jerome, CNRS, Inst Mediterraneen Ecol & Paleoecol, UMR 6116, F-13397 Marseille, France
[3] CNRS, Comis Nacl Energia Atom, Lab Sci Climat & Environm, F-91198 Gif Sur Yvette, France
[4] CNRS, Lab Glaciol & Geophys Environm, F-38402 St Martin Dheres, France
[5] Univ Aix Marseille 3, Lab Analyse, Fac Sci & Tech St Jerome, F-13397 Marseille, France