Structural mapping and kinematic history of the Qena-Safaga Shear Zone (Egyptian Nubian Shield, East African Orogen)

.E.El-Araby, Asmaa; D. Hagag, Wael.; Z.Kamh, Samir.; Hamimi, Zakaria; E.Hamimi, Zakaria.

doi:10.21608/bjas.2024.281703.1399

Structural mapping and kinematic history of the Qena-Safaga Shear Zone (Egyptian Nubian Shield, East African Orogen)

Document Type : Original Research Papers

Authors

¹ Geology Department, Faculty of Science, Benha University, Benha 13518, Egypt

² Geology Department, Faculty of Science, Tanta University, Tanta 31527, Egypt

³ Geology, Faculty of Science, Benha university, Egypt

10.21608/bjas.2024.281703.1399

Abstract

The Qena- Safaga Shear Zone (QSSZ) is a megashear belt separating the Northern- and the Central- Tectonic Provinces of the Egyptian Nubian Shield (ENS). Processing of remotely sensed data of the Landsat-8, ASTER and Sentinel 2A, accompanied by field/structural investigation made it possible to construct a plausible structural map for this high strain zone. A wide variety of Neoproterozoic litho-units outcrop in the area, including ophiolitic mélange, syn- tectonic granitoids, late- tectonic granitoids, Dokhan Volcanics and post- tectonic granitoids. Dike swarms traverse some of these units. The automatic lineament extraction using SRTM and PALSAR images verified that the dominant structural trend is the NE-SW. Other trends, comprising E-W (to ENE-WSW), NW-SE (to NNW-SSE) and N-S (to NNE-SSW) are also recognized. The main structural elements documented in the area embrace foliations and lineations, faults and shear zones, as well as shear zone-related structures (e.g. folds, duplexes and flower structures). The sense of movement along the aforementioned shear trends can be detected by a wide variety of kinematic indicators include mylonite, boudinage structure and deformed pebbles. The geological structures documented along the QSSZ indicate a brittle-ductile tectonic regime accompanied with voluminous granitic intrusions of various composition. Such structural and tectonic setting advocates a complex tectonic history characterized by extensional and transtensional tectonic regimes. The obtained results are significantly contributed to our knowledge on the high strain shear belts in the ENS.

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