Petrology and Geochemistry of some Upper Proterozoic Rocks

Some Upper Proterozoic rocks (serpentinites, metagabbro-diorite and granodiorite) of Homrit Waggat area, Central Eastern Desert of Egypt have been investigated. Geological, petrographical, and petrochemical parameters are carried out to throw some light on the discussion of origin and tectonic evolution for these concerned rocks. The petrographical and geochemical data confirm that the serpentinites were derived after Alpine-type peridotites (harzburgite) and dunite ultramafic parent rocks in the Supra Subduction Zone (SSZ) ophiolites which are affiliated to ocean floor tholeiites. The serpentinites are similar to Pan-African Bac-Arc ophiolites in Northeast and East Africa. Whereas the metagabbro-diorite and granodiorite exhibit a calc-alkaline affinity and clustered in an island arc environment.