Geochronology and petrogenesis of the Cryogenian Sukari granite intrusion, Central Eastern Desert, Egypt: Inferences from whole rock geochemistry, zircon U-Pb-Hf isotopes and trace elements

Abstract

: The Sukari granite intrusion is a trondhjemite-granodiorite-granite suite in the Central Eastern Desert (CED) of Egypt. The granites are calc-alkaline and slightly metaluminous to peraluminous (A/CNK molar ratios = 0.91–1.84). On SiO 2 variation diagrams, they exhibit trends of decreasing Al 2 O 3 , TiO 2 , Fe 2 O 3total , MgO, CaO, and Sr and increasing Th. The REE patterns are slightly fractionated {(La/Yb) N = 1.89–2.24} with moderate negative Eu anomalies (Eu/Eu* = 0.33 – 0.58). On primitive-mantle normalized trace element diagram, the granites show negative Nb, Ta, Sr, and Ti anomalies. These geochemical traits suggest that the Sukari granites had evolved by fractional crystallization of plagioclase and ferromagnesian minerals in an island arc tectonic environment. Zircons separated from the Sukari granites are HREE-enriched with positive Ce-and