Granites in the Tectonic Environs of the Nubian Shield, Egypt: Geochemical Characterizations and New Contributions.

The granites of the Nubian Shield in Egypt comprise four groups based on processing 955 chemical analyses. The Ophiolite Plagiogranite Group exist at Wadis Sukkari and Abu Dabbab within the two ophiolite belts namely Um Khasila-Atud-Sukkari-Ghadir and Um Khariga-Wadi Abu Dabbab. The Old Granites Group comprises six types, the Shaitian, quartz diorite, tonalite, adamellite, trondhjemite and calc-alkaline granodiorites. The Younger Granites are represented by two groups: a Group of biotite hornblende pink granite (viz; the normal granite)-the leucocratic granites-Aswan granites and a Group of muscovite-microcline-quartz-albite (MMQA) granite-muscovite granite-alkali feldspar granite-red granite and gneissose red granite. The Ophiolitic plagiogranites and the Old granites are exposed chiefly in the Southern tectonic domain and decreases in the Central tectonic domain while the younger granites except few outcrops such as the Aswan and the Mueilha granites are chiefly cropping out in the Central and chiefly in the Northern tectonic domains. The ophiolitic plagiogranites are ocean ridge granites, the Old Granites are subduction volcanic arc (island arc) granites, Younger Granites suturing collision compressional granites and Younger intraplate extensional rifting Granites.