1. Geoscience Institute, University of Bonn, Meckenheimer Allee 169, 53115 Bonn, Germany
2. † Present address: Department of Geology, Faculty of Science, Minia University,, 1 Misr Aswan Highway, 61519 Minia, Egypt.
3. Institute for Geology, Mineralogy and Geophysics, Ruhr-University of Bochum, Germany, Universitätsstrasse 150, 44780 Bochum, Germany
4. Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany