Explore the vast range of titles available.

This study presents a comprehensive analysis of mineralization exploration in the Egyptian Eastern Desert (ED), one of the most sought-after areas for those interested in mining industry, by integrating Landsat-9 images and geophysical magnetic data. Employing advanced techniques like Principal Component (PC) analysis, Minimum Noise Fraction (MNf) transform, and Band-Ratio (B-Ratio), the research focuses on mapping lithological units, hydrothermal alteration regions, and structural elements. Composite images derived from specific PC, and MNf bands, and B-Ratio exhibit superior lithological unit identification. The findings emphasize that there are significant variations in the types of rocks extend from the southern to the northern parts of the ED. Hydrothermal alteration mapping, guided by B-Ratio results, aids qualitative lithological discrimination. A novel false color composite image optimizes Landsat-9 B-Ratios, enhancing rock unit discrimination. Correlation analyses reveal associations between mineralization types and major lithological units, while exploration of the magnetic anomaly map highlights its role in correlating mineralization sites. Structural features, analyzed through Center for Exploration-Targeting Grid-Analysis (CET-GA) and Center for Exploration-Targeting Porphyry-Analysis (CET-GA) with Tilt Derivative of RTP (TDR) techniques, contribute to a robust association between regions with medium to high structural density and porphyry intrusions and mineralization. The study significantly supports the advanced exploration geoscience, providing insights into the geological structures and dynamics governing mineralization in the Egyptian ED.

Satellite-based multi-sensor data coupled with field and microscopic investigations are used to unravel the setting and controls of gold mineralization in the Wadi Beitan–Wadi Rahaba area in the South Eastern Desert of Egypt. The satellite-based multispectral and Synthetic Aperture Radar (SAR) data promoted a vibrant litho-tectonic understanding and abetted in assessing the regional structural control of the scattered gold occurrences in the study area. The herein detailed approach includes band rationing, principal component and independent component analyses, directional filtering, and automated and semi-automated lineament extraction techniques to Landsat 8- Operational Land Imager (OLI), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Phased Array L-band Synthetic Aperture Radar (PALSAR), and Sentinel-1B data. Results of optical and SAR data processed as grayscale raster images of band ratios, Relative Absorption Band Depth (RBD), and (mafic–carbonate–hydrous) mineralogical indices are used to extract the representative pixels (regions of interest). The extracted pixels are then converted to vector shape files and are finally imported into the ArcMap environment. Similarly, manually and automatically extracted lineaments are merged with the band ratios and mineralogical indices vector layers. The data fusion approach used herein reveals no particular spatial association between gold occurrences and certain lithological units, but shows a preferential distribution of gold–quartz veins in zones of chlorite–epidote alteration overlapping with high-density intersections of lineaments. Structural features including en-echelon arrays of quartz veins and intense recrystallization and sub-grain development textures are consistent with vein formation and gold deposition syn-kinematic with the host shear zones. The mineralized, central-shear quartz veins, and the associated strong stretching lineation affirm vein formation amid stress build-up and stress relaxation of an enduring oblique convergence (assigned as Najd-related sinistral transpression; ~640–610 Ma). As the main outcome of this research, we present a priority map with zones defined as high potential targets for undiscovered gold resources.

The Arabian Shield of Saudi Arabia represents part of the Arabian–Nubian Shield and forms an exposure of juvenile continental crust on the eastern side of the Red Sea rift. Gabbroic intrusions in Saudi Arabia constitute a significant part of the mafic magmatism in the Neoproterozoic Arabian Shield. This study records the first detailed geological, mineralogical and geochemical data for gabbroic intrusions located in the Gabal Samra and Gabal Abd areas of the Hail region in the Arabian Shield of Saudi Arabia. Geological field relations and investigations, supported by mineralogical and geochemical data, indicate that the gabbroic intrusions are generally unmetamorphosed and undeformed, and argue for their post-collisional emplacement. Their mineralogical and geochemical features reveal crystallization from hydrous, mainly tholeiitic, mafic magmas with arc-like signatures, which were probably inherited from the previous subduction event in the Arabian–Nubian Shield. The gabbroic rocks exhibit sub-chondritic Nb/U, Nb/Ta and Zr/Hf ratios, revealing depletion of their mantle source. Moreover, the high ratios of (Gd/Yb)N and (Dy/Yb)N indicate that their parental mafic melts were derived from a garnet-peridotite source with a garnet signature in the mantle residue. This implication suggests that the melting region was at a depth exceeding ∼70–80 km at the garnet stability field. They have geochemical characteristics similar to other post-collisional gabbros of the Arabian–Nubian Shield. Their origin could be explained by adiabatic decompression melting of depleted asthenosphere that interacted during ascent with metasomatized lithospheric mantle in an extensional regime, likely related to the activity of the Najd Fault System, at the end of the Pan-African Orogeny.

This study outlines the newly identified N–S dextral shear zone within the Egyptian Nubian Shield. The N–S Shear Zone (600–590 Ma) is a significant north-trending geological feature in the Egyptian Nubian Shield, extending over 140 km in length and reaching widths of up to 10 km. The N–S shear zone area is composed mainly of mylonitic schist, metavolcanics, metasediments, augen gneisses, and molasse sediments. The combination of remote sensing, magnetic analysis, and fieldwork in structural mapping has been extensively used, with developments in remote sensing technologies facilitating comprehensive structural geology mapping. Two Landsat-8 OLI/TIRS scenes with 30 m spatial resolution were used to upgrade the geologic map and extract major geological structures in a study area. Image kinematic indicators of the N–S shear zone (N–SSZ) were enhanced using processed remote sensing data. Geophysical magnetic and gravity data were used to unravel shallow and deep structures, with geophysical data analysis and edge detection interpretation revealing significant structural directions in the region. The gravity and magnetic data were upward continued to altitudes of 1, 2, and 4 km. Then, the Enhanced Horizontal Gradient Amplitude (EHGA) was applied to RTP and Bouguer and their upward continued data to delineate shallow and deep structures. The Bouguer anomalies outline N–S, NW, and E–W-directed structures, while magnetic data underline a previously unrecognized N–SSZ. The N–SSZ is characterized by a transpressive deformation regime, featuring a sub-horizontal pure shear component operating in conjunction with simple shear. As the deformation gradient intensifies, the influence of the simple shear component escalates, becoming the dominant factor in the ultramylonites located at the core of the shear zone. The N–S shear area is characterized by conjugate shear zones that emerged during the Najd Orogeny. The dominant shear plane is oriented in a NW–SE direction, while additional shear zones trending NE–SW and N–S serve as conjugate structures. Riedel structures create a network of shear bands, with the N–S dextral shear recognized as the X-shear. The N–SSZ plays a crucial role in controlling gold mineralization as well as other ore minerals such as chromite, copper, and nickel.

A low-to medium-grade metamorphic belt of a volcano-sedimentary succession occurs in the eastern side of South Sinai as a part of the northernmost extension of the Arabian–Nubian Shield in Egypt. The belt is known as the Kid metamorphic complex. It is considered as one of the major belt among the other exposed metamorphic belts in South Sinai. Here, we detect and investigate the signature of the Najd Fault system in South Sinai based on detailed structural analysis in field and digital image processing. The enhanced satellite image and the geo-spatial distributions confirm that the Kid belt is essentially composed of nine Precambrian units. Field relations and geometrical analysis of the measured structural data revealed that the study area underwent four successive deformational phases (D 1 –D 4 ). D 1 is an upright tight to isoclinal large-scale folds that caused few F 1 small-scale folds and a steeply dipping S 1 axial plane foliation. The second deformational event D 2 produced dominant of sub-horizontal S 2 foliation planes accompanied with recumbent isoclinal folds and NW–SE trending L 2 lineations. The main sense during D 2 was top-to-the-NW with local reversals to the SE. The third folding generations F 3 is recorded as axial plane S 3 -surfaces and is characterized by open concentric folding that overprinting both F 1 and F 2 folds and has a flexural-slip mechanism. F 3 fold hinges plunge to the west–northwest or east–southeast indicate north–northeast–south–southwest shortening during D 3 . The fourth deformational event D 4 is characterized by NE plunging open concentric folding overprint the pre-existing fold generations and formed under flexural slip mechanism reflecting coaxial deformation and indicating change in the stress regime as a result of the change in shortening from NE–SW to NW–SE. This phase is probably accompanied with the final assembly of east and west Gondwana. The dextral NW–SE shear zone that bounded the southwestern portion of the metamorphic belt is probably related to reactivation of the Najd fault system during Oligo-Miocene in South Sinai.