Origin and evolution of Neoproterozoic metaophiolitic mantle rocks from the eastern Desert of Egypt : Implications for tectonic and metamorphic events in the Arabian-Nubian Shield - Ali, Shehata (Minia University. Faculty of Science. Geology Department) ; Azer, Mokhles K. (National Research Centre. Geological Sciences Department) ; Abdel-Karim, Abdel-Aal M. (Zagazig University. Faculty of Science. Geology Department)