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<p>The tectonic setting and structural evolution of the Neoproterozoic basement complex exposed at both the Eastern Desert (ED) and southern Sinai (collectively known as the Egyptian Nubian Shield, ENS) are still a subject of controversy and a matter of contentious interpretation. Tectonically, the ED was recently subdivided into three tectonic provinces; northern extensional-, central transpressional- and southern compressional- provinces, each of which has its own characteristic features in terms of litho-stratigraphy and polyphase deformation history. The Wadi Kareim area lies in the central transpressional province and shows most of the key structural indicators of the Neoproterozoic deformation recorded elsewhere in the ENS. It contains the unique post-amalgamation depositional Kareim basin with a complete succession of the Hammamat Group. The present work aims to add a contribution to the geological setting and structural evolution of this key area.The exposed litho-units comprise metaultramafics, metagabbros, volcaniclastic metasediments, arc metavolcanics and Hammamat Sediments, post-Hammamat felsites and younger granite. These units experienced a prolonged history of deformation attested by a wide variety of structural fabrics, such as shearing and shear zone-related structures, and thrusting and thrust-related structures. Both shearing and thrusting are geometrically- and kinematically-related, and indicating a Neoproterozoic transpressional regime. Such tectonic setting can be easily detected at the outcrop-scale by the noticeable duplexes and flower structures, as well as the overprinting relations between stretched-slip lineations and other fabrics. The Kareim basin shares most diagnostic features of the larger basins in the ENS that localized to the area near the exposed Egyptian Eastern Desert Shear Zone. Geochemical analysis was conducted for some selected rock samples of metagabbros and granite to evaluate the petrogeochemical classification, magma type and tectonic setting. The results indicate that the metagabbros of both Wadi Kareim and Wadi El-Dabbah were formed following orogenic uplift. The investigated granitic samples reveal a within-plate (WPG) nature.</p>

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Contribution to the geology and structure of the Central Eastern Desert of Egypt (northwestern Arabian-Nubian Shield): insights from East Wadi Kareim area

  • 期刊论文

  • 发表日期：

    2026年1月22日

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  • Zakaria Hamimi,
  • Magdy M. Khalil,
  • Fatma M. El-Reefy,
  • Mahmoud K. Alawy,
  • Hoda Ragab Saad

摘要

The tectonic setting and structural evolution of the Neoproterozoic basement complex exposed at both the Eastern Desert (ED) and southern Sinai (collectively known as the Egyptian Nubian Shield, ENS) are still a subject of controversy and a matter of contentious interpretation. Tectonically, the ED was recently subdivided into three tectonic provinces; northern extensional-, central transpressional- and southern compressional- provinces, each of which has its own characteristic features in terms of litho-stratigraphy and polyphase deformation history. The Wadi Kareim area lies in the central transpressional province and shows most of the key structural indicators of the Neoproterozoic deformation recorded elsewhere in the ENS. It contains the unique post-amalgamation depositional Kareim basin with a complete succession of the Hammamat Group. The present work aims to add a contribution to the geological setting and structural evolution of this key area.The exposed litho-units comprise metaultramafics, metagabbros, volcaniclastic metasediments, arc metavolcanics and Hammamat Sediments, post-Hammamat felsites and younger granite. These units experienced a prolonged history of deformation attested by a wide variety of structural fabrics, such as shearing and shear zone-related structures, and thrusting and thrust-related structures. Both shearing and thrusting are geometrically- and kinematically-related, and indicating a Neoproterozoic transpressional regime. Such tectonic setting can be easily detected at the outcrop-scale by the noticeable duplexes and flower structures, as well as the overprinting relations between stretched-slip lineations and other fabrics. The Kareim basin shares most diagnostic features of the larger basins in the ENS that localized to the area near the exposed Egyptian Eastern Desert Shear Zone. Geochemical analysis was conducted for some selected rock samples of metagabbros and granite to evaluate the petrogeochemical classification, magma type and tectonic setting. The results indicate that the metagabbros of both Wadi Kareim and Wadi El-Dabbah were formed following orogenic uplift. The investigated granitic samples reveal a within-plate (WPG) nature.