Structural and tectonic evolution of suture‐related belts and post‐accretionary systems in the <scp>Arabian‐Nubian</scp> Shield

El‐Wahed, Mohamed Abd; Attia, Mohamed

doi:10.1002/gj.4693

Cited by 5 publications

(1 citation statement)

References 236 publications

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“…The thrust-dominated shortening or shortening accommodated by thrust and strikeslip shear zones is considered the dominate force that affected the Gerf area. Theoretically, the Gerf area is surrounded by two major sinistral shear zones; (i) Extension of NWstriking Kharit-Hodein shear zone [97] and (ii) Concealed shear zone west of Gerf nappe. Movement along these shear zones shaped the structure of the Gerf area that evolved throughout three deformation phases (D2, D3 and D4).…”

Section: Tectonic Evolution Of Gerf Areamentioning

confidence: 99%

Multisensor Satellite Data and Field Studies for Unravelling the Structural Evolution and Gold Metallogeny of the Gerf Ophiolitic Nappe, Eastern Desert, Egypt

et al. 2023

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The gold mineralization located in the southern Eastern Desert of Egypt mostly occurs in characteristic geologic and structural settings. The gold-bearing quartz veins and the alteration zones are confined to the ductile shear zones between the highly deformed ophiolitic blocks, sheared metavolcanics, and gabbro-diorite rocks. The present study attempts to integrate multisensor remotely sensed data, structural analysis, and field investigation in unraveling the geologic and structural controls of gold mineralization in the Gabal Gerf area. Multispectral optical sensors of Landsat-8 OLI/TIRS (L8) and Sentinel-2B (S2B) were processed to map the lithologic rock units in the study area. Image processing algorithms including false color composite (FCC), band ratio (BR), principal component analysis (PCA), minimum noise fraction (MNF), and Maximum Likelihood Classifier (MLC) were effective in producing a comprehensive geologic map of the area. The mafic index (MI) = (B13-0.9147) × (B10-1.4366) of ASTER (A) thermal bands and a combined band ratio of S2B and ASTER of (S2B3+A9)/(S2B12+A8) were dramatically successful in discriminating the ophiolitic assemblage, that are considered the favorable lithology for the gold mineralization. Three alteration zones of argillic, phyllic and propylitic were spatially recognized using the mineral indices and constrained energy minimization (CEM) approach to ASTER data. The datasets of ALSO PALSAR and Sentinel-1B were subjected to PCA and filtering to extract the lineaments and their spatial densities in the area. Furthermore, the structural analysis revealed that the area has been subjected to three main phases of deformation; (i) NE-SW convergence and sinistral transpression (D2); (ii) ~E-W far field compressional regime (D3), and (iii) extensional tectonics and terrane exhumation (D4). The gold-bearing quartz veins in several occurrences are controlled by D2 and D3 shear zones that cut heterogeneously deformed serpentinites, sheared metavolcanic rocks and gabbro-diorite intrusions. The information extracted from remotely sensed data, structural interpretation and fieldwork were used to produce a gold mineralization potential zones map which was verified by reference and field observations. The present study demonstrates the remote sensing capabilities for the identification of alteration zones and structural controls of the gold mineralization in highly deformed ophiolitic regions.

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Section: Tectonic Evolution Of Gerf Areamentioning

confidence: 99%

Multisensor Satellite Data and Field Studies for Unravelling the Structural Evolution and Gold Metallogeny of the Gerf Ophiolitic Nappe, Eastern Desert, Egypt

et al. 2023

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Integrating facies, mineralogy, and paleomagnetism to constrain the age and provenance of Paleozoic siliciclastic sedimentary rocks along the northern Gondwana margin: insights from the Araba and Naqus formations in western Gulf of Suez, Egypt

Al-Nashar,

Hafez,

El-Moghny

et al. 2024

Int J Earth Sci (Geol Rundsch)

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The depositional ages and provenance of the Paleozoic Araba and Naqus Formations along the northern Gondwanan margin in Egypt have remained uncertain due to a lack of index fossils. Resolving this issue is crucial for understanding regional geology during deposition and subsequent tectonic development. We integrate detailed facies analysis, anisotropy of magnetic susceptibility (AMS), paleomagnetism, and mineralogical data to elucidate the genesis and depositional ages of the Araba and Naqus Formations. Petrographic analyses identified seven distinct facies types, providing insights into sedimentary textures, maturity, and sources, with contributions from igneous and metamorphic sources indicated by heavy minerals. X-ray diffraction (XRD) analysis identified accessory minerals such as quartz, goethite, kaolinite, hematite, and anatase. Paleomagnetism isolated two magnetic components (CA and CN) providing the first robust paleo pole positions at Lat. = 70.8° N, Long. = 308.2° E and Lat. = 37.8° N, Long. = 233.1° E, indicating Cambrian and Carboniferous ages for the Araba and Naqus formations, respectively. Thermal demagnetization constrained these dates using established polarity timescales. Mineralogical data indicated that the Araba Formation originated from an igneous source, while the Naqus Formation had a mixed metamorphic-igneous provenance. The integrated AMS and paleomagnetic data reveal evidence of post-depositional deformation. Specifically, the clustering of maximum AMS axes in the NW–SE direction for both formations, suggests the initial presence of a primary depositional fabric. However, prevalent tectonic activity during the Cenozoic appears to have overprinted and modified this fabric through deformation related to rifting of the Gulf of Suez region. Through this novel multi-proxy approach, we have resolved long-standing uncertainties regarding the formations' depositional ages. Our study thereby provides the first chronostratigraphic framework for these strategically important sedimentary units, significantly advancing understanding of regional Paleozoic geology. Graphical abstract

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The structures control the evolution of molasse basins and alteration zones occurrences in the northwestern sector of the Central Eastern Desert of Egypt

Abd El-Wahed,

Kassem,

Abudeif

et al. 2024

Discov Geosci

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Integration between the analyses of both fieldwork and remote sensing dataset were employed to assess the structural evolution of molasse basins and explore gold mineral deposits in the El Qash area, Central Eastern Desert of Egypt. Sandstone, mudstones, wacke, and pebbly conglomerates make up most of the sediments in the molasse basins. The younger basins (595–575 Ma) are small, less weathered, and mostly Dokhan detritus-filled basins compared to the larger older basins (> 625–605 Ma), which have more weathered sources mainly of arc metavolcanics. The molasse basins appear to have originated in a north–south regional extensional setting, characterized by a prolonged period of left-lateral transtension combined with the formation of NNE-trending synformal folds during an ENE–WSW compression phase. Notably, en-echelon arrays of normal faults, oriented perpendicular to the boundary of the strike-slip shear zone, are a recurring feature in basins formed through transtension. Furthermore, oblique NE-SW compression played a role in generating SW-dipping thrust faults and regional folding with NW–SE orientation, along with the reactivation of transtensional normal faults in a reverse manner. Multispectral satellite imagery data and radar data are used to map the relevant lithological units, structures, and hydrothermal alteration zones. This study concludes that the regions where gold deposits may be explored in connection with prospecting alteration minerals include the area around the ophiolitic assemblages, and the granitic intrusions, in addition to the felsite and the molasse sediments contacts.

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Structural and tectonic evolution of suture‐related belts and post‐accretionary systems in the Arabian‐Nubian Shield

Cited by 5 publications

References 236 publications

Multisensor Satellite Data and Field Studies for Unravelling the Structural Evolution and Gold Metallogeny of the Gerf Ophiolitic Nappe, Eastern Desert, Egypt

Multisensor Satellite Data and Field Studies for Unravelling the Structural Evolution and Gold Metallogeny of the Gerf Ophiolitic Nappe, Eastern Desert, Egypt

Integrating facies, mineralogy, and paleomagnetism to constrain the age and provenance of Paleozoic siliciclastic sedimentary rocks along the northern Gondwana margin: insights from the Araba and Naqus formations in western Gulf of Suez, Egypt

The structures control the evolution of molasse basins and alteration zones occurrences in the northwestern sector of the Central Eastern Desert of Egypt

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