干旱区生态环境知识资源中心

The paper considers the Precambrian ring structures in an island arc and their associated mineralization in the southern Sinai. Several ring structures in an island arcsetting have been recognized within the volcanic field in southern Sinai including the Kid Ring structure, St. Katarina Ring Structure, and the Iqna Ring Structure. All ring structures are associated with mineralization, the largest one is the Kid Ring Structure located in southeastern Sinai, and represented by a succession of Dokhan volcanic and Hammamat sediments intruded by younger granites and albitite. The mineralization includes stockwork, rhyolite bearing-sulphide, alteration zones in the El Samra area, alteration zones, gossans, quartz veins, silicified carbonate metatuffs, and skarn mineralization in the Um Zerriq area. Geochemical investigation reveals that Wadi El Samra is dominated by Au-Cu-Zn. Wadi Ghorabi-El Hatemeia is dominated by Cu-Au mineralization, while the Wadi Khashm El Fahk is dominated by Cu-Au-Zn in the El Samra area. Um Zerriq I is dominated by Au-Cu-dominated mineralization, and the Um Zerriq II and III are dominated by Zn-Pb-Cu-Au. Major mineralization of the south Sinai is closely associated with last phase of volcanism within the ring structure, and is closely related in time and space to porphyritic, intermediate composition magma emplaced within the ring complex structures.