Title: The Ophiolite-Dominated Suprastructure, Eastern Desert, Egypt
Abstract: The Neoproterozoic rocks of Egypt represent the northwestern part of the Arabian-Nubian Shield (ANS), in which Late Tonian-Cryogenian ophiolite-dominated suprastructure assemblages are widespread in the Eastern Desert (ED) of Egypt. They include disrupted ophiolites, island arc metavolcanics and associated volcaniclastic sediments, ophiolitic melanges, bimodal arc metavolcanics and associated banded iron formation, and sulfides. Ophiolites commonly occur as dismembered rock sequences and rarely as intact uplifted blocks. The whole ophiolite-island arc assemblages are metamorphosed to greenschist facies. Field relationships and mode of occurrences, together with geochemical criteria are used to recognize and distinguish between different types of ophiolites. Geochemically, Neoproterozoic ophiolites fall into two distinct groups: MORB-like ophiolites and SSZ ophiolites. Formation of oceanic island arcs and related volcaniclastic sediments, followed by the bimodal-evolved island arcs and intra-arc sediments. Ophiolite blocks and fragments were incorporated into a volcaniclastic matrix forming an “ophiolitic mélange” through tectonic and/or concurrent sedimentary and tectonic processes. Ophiolites marking tectonic zones within the belt of the Nubian Shield that formed at more than one time with two evolution stages ~810–780 and ~730–750 Ma.
Publication Year: 2020
Publication Date: 2020-09-29
Language: en
Type: book-chapter
Indexed In: ['crossref']
Access and Citation
Cited By Count: 2
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot