A sheared Ophiolitic Mélange: Occurrence, Petrographical And Geochemical Studies, Around Wadi Fatira, North Eastern Desert, Egypt.

Bekir, R. Kh.; El Sheikh, A. A.; Saber, E. A; Shalaby, O. R.

doi:10.21608/sjsci.2022.234256

A sheared Ophiolitic Mélange: Occurrence, Petrographical And Geochemical Studies, Around Wadi Fatira, North Eastern Desert, Egypt.

Document Type : Regular Articles

Authors

Department of Geology, Faculty of Science, Sohag University, Egypt.

10.21608/sjsci.2022.234256

Abstract

The present study provides a new perspective on the nature and deformational development of the basement rocks in the Fatira area. The goal of the project is to characterise the mélange rocks in the area from a petrographic and geochemical standpoint. Field, petrographic and geochemical studies of the Neoproterozoic rocks in the Wadi Fatira area indicate that these rocks are sheared part of an ophiolitic suite. These rocks comprise serpentinites and their related rocks of talc carbonates and quartz carbonates, sheeted metadolerite, and pillowed metabasalts. The original ophiolitic suite has been deformed and suffered different degrees of shearing, leading to the formation of an ophiolitic mélange that is composed of fragments of the ophiolitic rocks set in a highly sheared mylonitized matrix. The geochemical data revealed that ophiolitic metavolcanics and their mylonites are mainly of basaltic and basaltic andesite composition. They are tholeiitic in nature and originated in an oceanic floor setting. These rocks were mylonitized by the effect of a NE–SW trending dextral shear zone in Wadi Fatira that may represent the second-order shear of the Najd fault system (NFS).

Keywords

Main Subjects

Geology

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