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1.

001-es BibID:BIBFORM124823
Első szerző:Abdelkader, Mohamed M.
Cím:Advanced exploration of rare metal mineralization through integrated remote sensing and geophysical analysis of structurally-controlled hydrothermal alterations / Mohamed A. Abdelkader, Yasushi Watanabe, Ali Shebl, Mohamed Badawi, Maher Dawoud, Hanaa A. El-Dokouny, Arpád Csámer, Mahmoud Abdellatif
Dátum:2024
ISSN:0375-6742
Megjegyzések:Fusing multi-source (remote sensing and geophysical) data and diverse approaches validation in targeting hydrothermal alteration and structural anomalies enhances the potential for accurately detecting and characterizing mineralization zones. Sentinel 2 data and ASTER were processed for lithological and hydrothermal alteration mapping in the rare metal-rich Umm Naggat area (Egypt). Different image processing techniques were implemented, including false color composites, minimum noise fraction, band rationing, band math, mineral indices, relative absorption band depth, and constrained energy minimization. The rare metal-bearing Umm Naggat younger granite (NYG) pluton was lithologically discriminated and intra-differentiated to mafic-rich biotite granites, mafic-poor alkali feldspar granites, and albitized granites. Extensive hydrothermal alterations, such as albitization, ferrugination, propylitization, argillization, and phyllitization, overprint the NYG pluton. Normalized standard deviation, automatic lineament extractions, and trend analysis highlighted the key structural directions (NW, NNW, NNE, and NE) and distinguished the NYG pluton as a moderate to high structural density zone. The high structural density and intensive alteration zones are spatially associated and more localized within the NYG pluton than the surrounding rocks. Spatial overlay analysis confirmed that the hydrothermal alterations and fluid circulation systems are structurally-controlled. Furthermore, the hydrothermal alteration mapping and structural analysis outcomes were verified by combining fieldwork, slab polishing, petrographic investigations, and mineral chemistry through semi-quantitative scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and quantitative electron probe microanalysis (EPMA) analysis. As a result, the hydrothermal genesis of rare metal-bearing minerals (Nb-rutile, Nb-ilmenite, and columbite) close to or incorporated within alteration minerals (chlorite, muscovite, and hematite) is confirmed from the alteration zones (propylitic, phyllic, and ferruginated). In addition, biotite muscovitization and chloritization significantly contribute to the secondary rare metal enrichment. The current study emphasizes the extensive distribution of secondary rare metal-bearing minerals within the entire NYG pluton (not only limited to the northern albitized granite as depicted by previous studies), which might shed light on these hydrothermally-altered younger granites as a new potential source for Nb and Ta in Egypt.
Tárgyszavak:Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Hydrothermal alterations
Rare metals
ASTER
Sentinel-2
Mineral chemistry
Arabian Nubian Shield
Megjelenés:Journal Of Geochemical Exploration. - 267 (2024), p. 1-32. -
További szerzők:Watanabe, Yasushi Shebl, Ali (1992-) (geológus) Badawi, Mohamed Dawoud, Maher El-Dokouny, Hanna A. Csámer Árpád (1976-) (geológus) Abdellatif, Mahmoud
Pályázati támogatás:Tempus Public Foundation
Egyéb
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2.

001-es BibID:BIBFORM104549
035-os BibID:(cikkazonosító)105184 (WoS)000881771600001 (Scopus)85142453471
Első szerző:Abdelkader, Mohamed M.
Cím:Effective delineation of rare metal-bearing granites from remote sensing data using machine learning methods: A case study from the Umm Naggat Area, Central Eastern Desert, Egypt / Mohamed A. Abdelkader, Yasushi Watanabe, Ali Shebl, Hanna A. El-Dokouny, Maher Dawoud, Árpád Csámer
Dátum:2022
ISSN:0169-1368
Megjegyzések:Albitized granite (ABG) is considered as one of the most significant hosts of rare metals (RMs). Consequently, adequate recognition of ABG through proper lithological discrimination highly increases the targeting of rare metal resources. In order to delineate outcrops of ABG from satellite data, our study integrates eight image enhancement techniques, including optimum index factor, false color composites, band rationing, relative band depth, independent component analysis, principal component analysis, decorrelation stretch, minimum noise fraction transform, and spectral indices ratios, for the interpretation of ASTER and Sentinel-2 (S2) datasets. This integrated approach allows the effective discrimination of AGB outcrops in the Umm Naggat area, Central Eastern Desert, Egypt. The interpretation maps derived from these integrated image processing techniques were systematically verified in the field and formed the base for the feature selection process (i.e., training and testing data delineation) of different lithologies supported by the support vector machine algorithm (SVM). In order to produce a high-quality lithological interpretation map, SVM was applied to Sentinel-2, ASTER, and combined ASTER-S2 datasets. The fused ASTER-S2 classification properly delineates ABG, as verified by our field investigations and confirmed by previous geological maps. Furthermore, comprehensive structural analysis (lineaments extraction and their density map) and hydrothermal alteration detection were performed to check the spatial association between the distribution of ABG, higher density zones, and highly altered areas, that in turn, could shed light on new potentially mineralized zones and proposed exploration targets. Our study reveals new ABG occurrences mainly situated in the southern and southwestern parts of the study area, and it confirms the location of known mineralized zones in the northern part of the Umm Naggat region. The distribution of ABG and its spatial correlation with alteration and high structural density zones suggest that rare-metal mineralization is mostly structurally controlled (NW, NNW, NNE, and N-S), demonstrating the higher possibility of metasomatic enrichment of rare-metals within the study area. Our study provides an updated geological map of the study area based on the SVM-supported interpretation of ASTER-S2 data. Importantly, the results reveal a high exploration potential for rare-metal mineralization at Umm Naggat and defining new anomalies for follow-up work by geochemical soil surveys.
Tárgyszavak:Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Sentinel-2
ASTER
Support Vector Machine
Albitized granite
Integrated image processing techniques
Rare-metal exploration
Central Eastern Desert
Egypt
Megjelenés:Ore Geology Reviews. - 150 (2022), p. 1-26. -
További szerzők:Watanabe, Yasushi Shebl, Ali (1992-) (geológus) El-Dokouny, Hanna A. Dawoud, Maher Csámer Árpád (1976-) (geológus)
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3.

001-es BibID:BIBFORM122872
Első szerző:Shebl, Ali (geológus)
Cím:PRISMA vs. Landsat 9 in lithological mapping - a K-fold Cross-Validation implementation with Random Forest / Ali Shebl, Dávid Abriha, Maher Dawoud, Mosaad Ali Hussein Ali, Arpád Csámer
Dátum:2024
ISSN:1110-9823 2090-2476
Megjegyzések:The selection of an optimal dataset is crucial for successful remote sensing analysis. The PRISMA hyperspectral sensor (with 240 spectral bands) and Landsat OLI-2 (boasting high dynamic resolution) offer robust data for various remote sensing applications, anticipating their increased demand in the coming years. However, despite their potential, we have not identified a rigorous evaluation of both datasets in geological applications utilizing Machine Learning Algorithms. Consequently, we conduct a comprehensive analysis using Random Forest, a widely-recommended machine learning algorithm, and employ K-fold cross-validation (with K = 2, 5, 10) with grid-search hyperparameter tuning for enhanced performance. Toward this aim, diverse image-processing ap- proaches, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Independent Component Analysis (ICA), were applied to enhance feature selection and extraction. Subsequently, to ensure better performance of the RF algorithm, this study utilized well-distributed points instead of polygons to represent each target, thereby mitigating the effects of spatial autocorrelation. Our results reveal dataset- hyperparameter dependencies, with PRISMA mainly influenced by max_depth and Landsat 9 by max_features. Employing grid-search optimally balances dataset characteristics and data splitting (folds), generating accurate lithological maps across all K values. Notably, a significant hyperparameter shift at K = 10 produces the best lithological maps. Fieldwork and petrographic investigations validate the lithological maps, indicating PRISMA's slight superiority over Landsat OLI-2. Despite this, given the dataset nature and band count difference, we still advocate Landsat 9 as a potent multispectral input for future applications due to its superior radiometric resolution.
Tárgyszavak:Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
PRISMA
Landsat 9
Random forest
Geological mapping
Megjelenés:Egyptian Journal of Remote Sensing and Space Science. - 27 : 3 (2024), p. 577-596. -
További szerzők:Abriha Dávid (1995-) (geográfus) Dawoud, Maher Ali Hussein Ali, Mosaad Csámer Árpád (1976-) (geológus)
Pályázati támogatás:K138079
NKFIH
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4.

001-es BibID:BIBFORM121482
035-os BibID:(Scopus)85192262100
Első szerző:Shebl, Ali (geológus)
Cím:Novel comprehensions of lithological and structural features gleaned via Sentinel 2 texture analysis / Shebl, Ali; Badawi, Mohamed; Dawoud, Maher; Abd El-Wahed, Mohamed; El-Dokouny, Hanna A.; Csámer, Árpád
Dátum:2024
ISSN:0169-1368
Tárgyszavak:Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Ore Geology Reviews. - 168 (2024), p. 1-26. -
További szerzők:Badawi, Mohamed Dawoud, Maher Abd El-Wahed, Mohamed El-Dokouny, Hanna A. Csámer Árpád (1976-) (geológus)
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5.

001-es BibID:BIBFORM111657
035-os BibID:(Scopus)85157963782 (WoS)001025221700001
Első szerző:Shebl, Ali (geológus)
Cím:Towards better delineation of hydrothermal alterations via multi-sensor remote sensing and airborne geophysical data / Ali Shebl, Mahmoud Abdellatif, Mohamed Badawi, Maher Dawoud, Amr S. Fahil, Árpád Csámer
Dátum:2023
ISSN:2045-2322
Megjegyzések:Integrating various tools in targeting mineral deposits increases the chance of adequate detection and characterization of mineralization zones. Selecting a convenient dataset is a key for a precise geological and hydrothermal alteration mapping. Remote sensing and airborne geophysical data have proven their efficiency as tools for reliable mineral exploration. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced land imager (ALI), Landsat 8 (L8), and Sentinel 2 data are widely?used data among various types of remote sensing images in resolving lithological and hydrothermal alteration mapping over the last two decades. ASTER is a well?established satellite in geological remote sensing with detailed Short?wave infrared (SWIR) range compared to visible and near?infrared region (VNIR) that controls iron?associated alteration detection. On contrary, ALI has excellent coverage of the VNIR area (6 bands), but does not possess the potentiality of ASTER for the SWIR and thermal regions. Landsat 8 is widely used and highly recommended for lithological and hydrothermal alteration mapping. The higher spatial (up to 10 m) resolution of Sentinel 2 MSI has preserved its role in producing accurate geological mapping. Notwithstanding the foregoing, implementing the four datasets in a single study is time?consuming. Thus, an important question when commencing an exploration project for hydrothermal alterations?related mineralization (orogenic mineral deposits in the current research) is: which dataset should be adopted to fulfill proper and adequate outputs? Here the four widely recommended datasets (ASTER, ALI, L8, and sentinel 2) have been tested by applying the widely?accepted techniques (false color combinations, band ratios, directed principal component analysis, and constrained energy minimization) for geological and hydrothermal alteration mapping of Gabal El Rukham?Gabal Mueilha district, Egypt. The study area is covered mainly by Neoproterozoic heterogeneous collection of ophiolitic components, island arc assemblage, intruded by enormous granitic rocks. Additionally, airborne magnetic and radiometric data were applied and compared with the remote sensing investigations for deciphering the structural and hydrothermal alteration patterns within the study area. The results demonstrated a different extent from one sensor to another, highlighting their varied efficacy in detecting hydrothermal alterations (mainly hydroxyl?bearing alterations and iron oxides). Moreover, the analysis of airborne magnetic and radiometric data showed hydrothermal alteration zones that are consistent with the detected alteration pattern. The coincidence between high magnetic anomalies, high values of the K/eTh ratio, and the resultant alterations confirm the real alteration anomalies. Over and above that, the remote sensing results and airborne geophysical indications were verified with fieldwork and petrographic investigations, and strongly recommend combining ASTER and Sentinel 2 results in further investigations. Based on the outputs of the current research, we expect better hydrothermal alteration delineation by adopting the current findings as they sharply narrow the zones to be further investigated via costly geophysical and geochemical methods in mineral exploration projects.
Tárgyszavak:Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Scientific Reports. - 13 : 1 (2023), p. 1-27. -
További szerzők:Abdellatif, Mahmoud Badawi, Mohamed Dawoud, Maher Fahil, Amr S. Csámer Árpád (1976-) (geológus)
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