Origin of the post-collisional younger gabbroic rocks and the associated Fe–Ti oxide ores, Abu Ghalaga area, Southern Eastern Desert, Egypt: mineralogical and geochemical constraints

Abstract The Abu Ghalaga pluton in the southern eastern desert of Egypt (SED) consists undeformed norite and hornblende gabbro intruding island arc metavolcanics, ophiolitic rocks, syn-tectonic older granitic rocks. Fe-Ti ore (mainly ilmenite) occurs form lenses at base norite. Based on microtextures, mineralogy, chemical composition, three types ilmenites are recognized: massive high-Mg type, disseminated low-Mg ilmenite. ilmenite chemically distinguished by their MgO, MnO, TiO 2 , Fe O 3 FeO, V contents. variations concentration these oxides interpreted as a function T, f composition parental magma. Reconstruction orthomagmatic conditions shows that T magma from which its deposit formed decrease during course magmatic differentiation, whereas mineralization have more evolved under relatively lower . REE patterns variation diagrams support model crystal fractionation primary means formation deposits. Chemical features also suggest parent both gabbroic rocks was generated mantle, but two different pulses. Subduction zone, MORB, WPB signatures for complex tectonic history consistent with compression followed within plate extension possibly contributing to development back-arc/intra-arc basin.