Hadrien Pirotte, University of Liege, Liège, Belgium, Camille Cartier, CRPG Centre de Recherches Pétrographiques et Géochimiques, Vandoeuvre-Les-Nancy, France, Olivier Namur, University of Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium, Anne Pommier, University of California San Diego, La Jolla, CA, United States and Bernard Charlier, University of Liège, Department of Geology, Sart Tilman, Belgium