Structural evolution of Wadi Road El-Sayalla area, Eastern Desert, Egypt

• Main Authors: Khaled Gamal ALI, Hassan Ali ELIWA, Masoud Salah MASOUD, Mamoru MURATA, Ahmed El Sayed ABDEL GAWAD
• Format: Article
• Language: deu
• Published: Ural State Mining University 2018-12-01
• Series: Izvestiâ Uralʹskogo Gosudarstvennogo Gornogo Universiteta
• Subjects: Wadi Road El-Sayalla; Nikeiba; Fileita; Egypt; folding-thrusting; cratonization; folding episode; faulting episode
• Online Access: https://iuggu.ru/en/4-18-1

Wadi Road El-Sayalla area is a part of the south Eastern Desert of Egypt. It comprises two plutons, Nikeiba basement rock complexes and Fileita Nubian sandstone. It is composed of metavolcanics, syenogranite, alkali feldspar granite and quartz syenite intruded by felsite and dolerite dikes and quartz veins at Nikeiba plutons which non-conformable overlain by Nubian sandstones at Fileita area. Purpose of the work. The present work of this paper is to elucidate the interaction between inherited ductile fabrics and overprinting brittle structures. It is important to reconstruct the tectonic evolution of Wadi Road El-Sayalla area which help in constraining the mineralization trends in the study area. Research methods. The folding related to ductile structures were analyzed using stereographic projection software packages GE Orient version 9.4.5. The fracture analyses related to brittle structures were carried out quantitatively using the paleostress analyses of the different sets to calculate the tensors related to the different compressional and extensional events using Tensor program. Results. Structural evolution in the investigated area enabled the separation of five structural episodes: E1: syn-tectonic granite (tonalite-granodiorite); folding-thrusting episode associated with the cratonization of the arc/inter-arc rocks association. E2: Late-tectonic granite; upright folding episode associated with compression and shortening to the NE-SW direction. E3: Post-tectonic granite intrusion episode produced syenogranite and alkali feldspar granite of Nikeiba. E4 and E5: Early Cretaceous to Post Pleistocene episode is manifested by syncline folding along ENE-WSW detected in the Nubian sandstone of Fileita (E4). On the other hand, E5: Fracturing, faulting episode is characterized by multi-trends of fault populations (E-W strike slip (right; oldest), N-S strike slip (left), E-W dip slip, NE-SW strike slip (right) and NE-SW dip slip (youngest). Accessories as thorite, uranothorite, monazite, zircon, allanite, yttrocolombite and fluorite appear to be structurally controlled by the interaction between inherited ductile fabrics and overprinting brittle structures. The NE-SW, NW-SE, E-W, NNW-SSE and N-S normal faults are considered to be important deep seated structure trends which controlled many injections of felsite and dolerite dikes and alteration features that could have acted as good pathways for mineralization.