Late Precambrian ophiolitic mélange in the eastern desert of Egypt

Abstract

Serpentinite masses in late Precambrian sediments of the eastern desert of Egypt are in a mélange with associated metagabbros and pillow lavas; they represent pieces of Precambrian oceanic crust. The mélange is of regional extent and is interpreted as a olistostrome which has been thrust northwestwards over shelf sediments and is overlain by island arc volcanics: thus the observed sequence is a structural rather than a stratigraphic one. A plate tectonic model is implied with a suture to the south-east. The interpretation of the late Precambrian (Pan-African) fold belts in Africa is controversial. It is uncertain whether, like Phanerozoic fold belts, they were formed by plate tectonic processes1-5, or whether they are ensialic and unrelated to subduction of oceanic crust6,7 or collision of continental plates. Here we present evidence relating to this problem from the part of the Pan-African belt exposed in the eastern desert of Egypt. © 1980 Nature Publishing Group.