The current contribution conducted new geochemical, remote sensing integrated with gravity detailed studies of talc deposits to identify the talc protolith as well as its extension, depth, and structures. There are two examined areas, distributed from north to south, Atshan and Darhib and both belong to the southern sector of the Egyptian Eastern Desert. They occur as individual lenses or pocket bodies in ultramafic-metavolcanics following NNW-SSE and E-W shear zones. Geochemically, among the investigated talc, Atshan samples have high contents of SiO₂ (av. 60.73 wt.%), and higher concentrations of transition elements such as Co (av. 53.92 ppm), Cr (781 ppm), Ni (av. 1303.6 ppm), V (av. 16.67 ppm), and Zn (av. 55.7 ppm). Notably, the examined talc deposits contain low contents of CaO (av. 0.32 wt.%), TiO₂ (av. 0.04 wt.%), SiO₂/MgO (av. 2.15), and Al₂O₃ (av. 0.72 wt.%), which is comparable with ophiolitic peridotite and forearc setting. False color composite (FCC), principal component analysis (PCA), minimum noise fraction (MNF), and band ratio (BR) have been used to distinguish talc deposits in the investigated areas. Two new proposed band ratios were created to separate talc deposits. FCC band ratios (2/4, 4/7, 6/5) and (4 + 3/5, 5/7, 2 + 1/3) have been derived to focus on talc deposits in two case studies, Atshan and Darhib areas. The application of regional, residual, horizontal gradient (HG), and analytical signal (AS) techniques to gravity data are used in interpreting the structural directions of the study area. The analysis of this technique displays several notable faults trending in NW–SE, NE–SW, NNW–SSE, and E–W directions. Two techniques of gravity depth calculation were applied in the study areas, namely source parameter image (SPI), and Euler deconvolution (EU). The analysis of these techniques reflects that the depth of subsurface sources ranges between 383 and 3560 m. Talc deposits may be attributed to greenschist facies metamorphism or to a magmatic solution that is (associated with granitic intrusions) interacted with the surrounding volcanic rocks forming metasomatic minerals.

The Wadi Samra–Wadi Kid district in southeastern Sinai, Egypt, has undergone extensive investigation involving remote sensing analysis, field geology studies, petrography, and geochemistry. The main aim of this study is the integration between remote sensing applications, fieldwork, and laboratory studies for accurate lithological mapping for future mineral exploration in the study region. The field relationships between these coincident rocks were studied in the study area. Landsat-8 (OLI) data that cover the investigated area were used in this paper. The different rock units in the study area were studied petrographically using a polarizing microscope, in addition to major and trace analysis using ICP-OES tools. The Operational Land Imager (OLI) images were used with several processing methods, such as false color composite (FCC), band ratio (BR), principal component analysis (PCA), and minimum noise fraction (MNF) techniques for detecting the different types of rock units in the Wadi Kid district. This district mainly consists of a volcano-sedimentary sequence as well as diorite, gabbro, granite, and albitite. Geochemically, the metasediments are classified as pelitic graywackes derived from sedimentary origin (i.e., shales). The Al₂O₃ and CaO contents are medium–high, while the Fe₂O₃ and TiO₂ contents are very low. Alkaline minerals are relatively low–medium in content. All of the metasediment samples are characterized by high MgO contents and low SiO₂, Fe₂O₃, and CaO contents. The granitic rocks appear to have alkaline and subalkaline affinity, while the subalkaline granites are high-K calc-alkaline to shoshonite series. The alkaline rocks are classified as albitite, while the calc-alkaline series samples vary from monzodiorites to granites. The outcomes of this study can be used for prospecting metallic and industrial mineral exploration in the Wadi Kid district.

This study addresses the long-standing challenge of accurately distinguishing ophiolitic rock units in the structurally complex terrains South Eastern Desert of Egypt’s. By integrating multispectral satellite data from Sentinel 2 and Landsat 9 (OLI 2) with substantial field investigation and petrographic analyses, this research proposes an enhanced methodological framework for precise lithological mapping of the Wadi Ghadir ophiolitic complex. Advanced enhanced digital image processing methods for False Color Composites (FCC), Band Ratios (BR), Minimum Noise Fraction (MNF), Principal Component Analysis (PCA), and Maximum Likelihood (ML) classification were systematically applied and evaluated. A newly proposed band ratio combination of Landsat-9 (6/7, 6/5, 6/3) proved highly effective in differentiating serpentinite, talc-carbonate, metagabbro, sheeted dykes, and pillow lavas, while PCA and MNF transforms improved separation of granitic, metasedimentary, and volcanic units. The resulting 1:25,000 scale geological map demonstrates the innovation of integrating complementary satellite sensors with ground validation to overcome spectral confusion and mapping limitations typical of Neoproterozoic ophiolitic terranes. This integrated workflow enhances geological interpretation accuracy and provides a cost effective, reproducible approach for regional mineral exploration and mapping in similar environments.

The Wadi Shait–Wadi Gemal district, within the Hafafit metamorphic dome of Egypt’s South Eastern Desert, represents a structurally complex segment of the Arabian Nubian Shield where garnet-bearing rocks are difficult to distinguish using conventional mapping. This study addresses this issue by integrating multi-sensor remote sensing (Landsat-9 and ASTER) with detailed field and petrographic investigations. Advanced image processing techniques, including false color composites (FCC), principal component analysis (PCA), minimum noise fraction (MNF), and proposed band ratios (BRs), were applied to enhance lithological discrimination and improve the detection of garnetiferous units. Field and petrographic analyses confirmed three principal garnet-bearing lithologies: garnet–muscovite–biotite schists, psammitic gneisses, and pegmatites. Garnet porphyroblasts were observed within quartz-mica matrices, reflecting a complex metamorphic history involving multiple deformation phases. The integration of remote sensing with petrological data allowed the production of a refined geological map and the precise delineation of garnet-enriched zones. This combined approach proved effective in resolving lithological complexities and significantly improves the understanding of garnet distribution in Precambrian metamorphic terranes.

Remote sensing represents a significant function in the exploration of minerals. Extraction and identification of mineral occurrences in semi-arid to arid regions are some of the remote sensing confirmed uses. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images have been combined with band ratio processing technique for detecting the fluorite mineral occurrences in the area around Gabal Abu Diyab, Central Eastern Desert, Egypt. The proposed band ratio derived from ASTER images Spectra [(b8/b6) * (b5/b3)] can be considered to represent the new Fluorite Index (FI). The USGS Spectral libraries are used to extract the new index and validated it by using the field study. According to the given new Fluorite Index (FI) combined with the field observations, two occurrences of fluorite mineralization at Gabal Homrit Waggat and Gabal Ineigi have been identified. This study provides the proposed FI as a beneficial tool for fluorite exploration that could be applicable along with Arabian Nubian Shield and similar arid and semi-arid environments.