Petrogenesis of ilmenite-bearing mafic intrusions: A case study of Abu Ghalaga area, South Eastern Desert, Egypt

Abstract Neoproterozoic Abu Ghalaga ilmenite-bearing mafic rocks were subjected to geological, petrographical and geochemical studies integrated with mineral chemistry of ilmenite, pyrite magnetite in order deduce their petrogenesis. intrusions hosting the largest ilmenite reserve Egyptian part Arabian-Nubian Shield. Field observations revealed that impound ore, which occurs as interlayer massive bands or disseminated within gabbroic rocks. Petrographically, include different kinds gabbro; olivine pyroxene gabbro, hornblende altered gabbro Fe-Ti-rich gabbro. They have calc-alkaline tholeiitic magmas, are depleted high field strength elements (e.g., Ta, Nb Th) relative low Ba, Sr Rb), exhibit light rare earth enrichment heavy positive Eu anomaly (Eu/Eu*= 0.8-2.4). Variable mineralogical wide variation bulk rock geochemistry ascribed fractional crystallization hydrothermal overprinting. derived from mantle magmas modified by ascending fluids subducted slab volcanic arc setting. Fe-Ti oxides required oxygen fugacity (ƒO2) water contents crystal settling Ti-rich is applicable subduction It can be inferred neither related ophiolite nor Alaskan type but one layered oxides.