Pan-African crustal evolution in the Nubian segment of northeast Africa

Abstract

Similarities in rock assemblages and facilitated thrust stacks of juvenile assemblages broad tectonic features between the late Precam-to override the ancient cratonic edge that may now brian to early Paleozoic basement of Arabia, the be buried beneath the SE Desert of Egypt. models that were proposed for Arabia, although at of Egypt and in Arabia, and they supported the least 2 of the Nubian ophiolite belts clearly con-arc accretion model developed for these regions. tinue into the Arabian shield. Subsequently Vail (1976) attempted to integrate The Pan-African structural domain with low-angle the Red Sea Hills into the geology of the entire thrusts and ophiolite m•langes extends at least as Arabian-Nubian shield and suggested that the far W as the River Nile, where the ancient margin "greenschist assemblages" were part of the same of the African craton may be found, The entire Pan-African crustal domain as the Eastern Desert domain farther E is characterized by newly accre-of Egypt and the Arabian basement, while he conted magmatic associations of late Precambrian age sidered the high-grade gneisses at the River Nile that may have evolved in settings similar to those to represent the edge of the ancient African crapresently observed in the Indonesian archipelago. ton. Further work led to a first evolutionary (]976) were the first to recognize the similarity these rocks is revealed by the local presence of of rock types and their tectonic settings in the sillimanite, while primary sedimentary structures NE Red Sea Hills with those in the Eastern Desert were largely destroyed by intense deformation and 236 KRONER ET AL.

Reconnaissance oxygen and sulfur isotopic mapping of Pan-African alkali granites and syenites in the southern Indian Shield.

“…1). The major tectonothermal event towards the end of Precambrian, first recognized in Africa and termed Pan-African event (Ken nedy, 1964), is now known to be widely represented throughout the Gondwana con tinents (Kroner, 1980). Temporally and geochemically, the southern Indian plutons are broadly coincident with those found in the Pan African and Afro-Arabian Shield.…”

Um Samra-Um Bakra Shear Zone, Central Eastern Desert, Egypt: Example of Vein -Type Base Metal Mineralization

“…The intercalation between volcanoclastic and volcano-sedimentary is a dominant character in the Egyptian Shield (Kroner et al, 1987). The studied volcanogenic rocks are fine-to medium -grained, banded, laminated and ranging in composition from fine tuffs through banded and lithic crystals tuffs to lapilli tuffs and intercalated with banded iron ore (BIF).…”

Geological, Geochemical and Mineralogical of the Iron Ore Deposit of Sabah, Al-Bayda'aarea, Yemen.

“…The Arabian -Nubian shield is a part of the east African orogeny , formed in the late Proterozoic (900 -550 Ma) by accretion amalgamation of oceanic and continental magmatic arcs and accretionary prisms during closure of the Mozambique ocean, suturing East and West Gondwana (Bentor, 1985, Kroner, et al, 1987, Stern, 1994, Al Selwi, 2005. In correlation with the accretionary history of the shield Saudi Arabia, northern Somalia and in Eritrea, the Neoproterozoic basement of Yemen is a part of the Arabian shield composed of a number of accreted arc terrains and inter arc suture zones (Beydoun, 1970, Gass, 1981, Al-Shanti and Gass,1983,Stoesser and Camp, 1985, Agar, etal., 1992.…”