1. Institute of Geosciences; Goethe University Frankfurt; Altenhöferallee 1,; D-60438; Frankfurt; Germany
2. Department of Geological and Environmental Sciences; Stanford University; 450 Serra Mall, Building 320,; Stanford; California; 94305; USA
3. Department of the Geophysical Sciences; University of Chicago; 5734 South Ellis Avenue, HGS 277,; Chicago; Illinois; 60637; USA
4. Administration des Ponts et Chaussées, Service Géologique; 43 Boulevard G.-D. Charlotte,; L-1331; Luxembourg; Luxembourg
5. Geological Institute; University of Neuchâtel; Rue Emile Argand 11,; CH-2009; Neuchâtel; Switzerland
6. Institute of Marine and Coastal Sciences; Rutgers University; 71 Dudley Road,; New Brunswick; New Jersey; 08901; USA