The research carried out in the Séguéla diamondiferous district in West-central Côte d'Ivoire (Paleoproterozoic domain) has led to the discovery and artisanal exploitation of diamonds. The area is characterized by kimberlite to lamproite dykes and pipes, as well as alluvium and colluvium in which diamonds are found. However, these formations (kimberlite and lamproite dykes) are covered by sedimentary deposits, which prevent them from outcropping. Therefore, the only indicators that can be linked to them are their weathering minerals. This study aims to identify minerals that could be diamond indicators. Three distinct types of concentrates of alluvium, colluvium and kimberlite concentrates are used to test this. The mineralogical study of these concentrates under a binocular microscope revealed diamond, as well as a high proportion ilmenite, olivine and chromite. The chemical analysis revealed the presence of magnesian ilmenites in the Séguéla concentrates, which would be derived from kimberlite (either Toubabouko or Bobi). In addition, kimberlitic activity in the Séguéla region suggests a possible link with that observed in the West African Craton (Sierra-Leone, Liberia, and Guinea). Finally, despite the absence of pyrope garnet in the concentrates, the following minerals: ilmenite (Mg-Ilmenite), olivine and chromite may serve as diamond indicators for deposits in the Séguéla region.
{"title":"Diamond indicator minerals: The case of the Séguéla diamondiferous provinces, West-central Côte d'Ivoire, Southern part of the West African Craton","authors":"Ziandjêdé Hervé Siagné , Koffi Alexis N'dri , Kouadio David Koffi , Miryam Tessia , Marc Ephrem Allialy , Yacouba Coulibaly","doi":"10.1016/j.jafrearsci.2026.106015","DOIUrl":"10.1016/j.jafrearsci.2026.106015","url":null,"abstract":"<div><div>The research carried out in the Séguéla diamondiferous district in West-central Côte d'Ivoire (Paleoproterozoic domain) has led to the discovery and artisanal exploitation of diamonds. The area is characterized by kimberlite to lamproite dykes and pipes, as well as alluvium and colluvium in which diamonds are found. However, these formations (kimberlite and lamproite dykes) are covered by sedimentary deposits, which prevent them from outcropping. Therefore, the only indicators that can be linked to them are their weathering minerals. This study aims to identify minerals that could be diamond indicators. Three distinct types of concentrates of alluvium, colluvium and kimberlite concentrates are used to test this. The mineralogical study of these concentrates under a binocular microscope revealed diamond, as well as a high proportion ilmenite, olivine and chromite. The chemical analysis revealed the presence of magnesian ilmenites in the Séguéla concentrates, which would be derived from kimberlite (either Toubabouko or Bobi). In addition, kimberlitic activity in the Séguéla region suggests a possible link with that observed in the West African Craton (Sierra-Leone, Liberia, and Guinea). Finally, despite the absence of pyrope garnet in the concentrates, the following minerals: ilmenite (Mg-Ilmenite), olivine and chromite may serve as diamond indicators for deposits in the Séguéla region.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106015"},"PeriodicalIF":2.2,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The primary aim of this study is to build an anisotropic geomechanical model (AGM) using well log data from Frasnian-aged shale in the Algerian Timimoun Basin. However, the lack of a shear delay time log (DTS) in one of the six available wells limits AGM analysis, as it is crucial for quantifying mechanical properties. Thus, to address this limitation, two approaches are adopted. Artificial intelligence (AI) algorithms and the single attribute regression (SAR) method. The AI-based model was trained first by integrating multiple well log data as inputs. Then, it incorporates only the compressional delay time (DTC) log. Furthermore, SAR generates an empirical equation by cross-plotting the DTC log versus the DTS log from four wells where the DTS log is available. Model validation is applied to the fifth unseen well from the same field. As a result, the SAR was a good measurement of the target log, reflecting similar geological variation as the DTC log along the studied interval, with a strong correlation coefficient (R2) of 0.97. Otherwise, the AI algorithms indicate a reliable performance with high accuracy (R2) and low values of root mean square error (R2∼0.96, RMSE∼0.1) for the first training. Compared with the first run, the second run is less accurate (R2∼0.8, RMSE∼0.26). Moreover, the AI-based model produced logs lacking the detailed variability of actual measurements while reducing prediction error and noting the high-frequency variation of the outputs, which may be due to the regularization and averaging effects of the algorithms.
{"title":"Addressing the shear delay time log deficiency in the Timimoun Basin: A comparative study of AI algorithms and single attribute regression for geomechanical modelling","authors":"khalda ZABEL, mohamed cherif BERGUIG, rachid KETTEB","doi":"10.1016/j.jafrearsci.2026.106002","DOIUrl":"10.1016/j.jafrearsci.2026.106002","url":null,"abstract":"<div><div>The primary aim of this study is to build an anisotropic geomechanical model (AGM) using well log data from Frasnian-aged shale in the Algerian Timimoun Basin. However, the lack of a shear delay time log (DTS) in one of the six available wells limits AGM analysis, as it is crucial for quantifying mechanical properties. Thus, to address this limitation, two approaches are adopted. Artificial intelligence (AI) algorithms and the single attribute regression (SAR) method. The AI-based model was trained first by integrating multiple well log data as inputs. Then, it incorporates only the compressional delay time (DTC) log. Furthermore, SAR generates an empirical equation by cross-plotting the DTC log versus the DTS log from four wells where the DTS log is available. Model validation is applied to the fifth unseen well from the same field. As a result, the SAR was a good measurement of the target log, reflecting similar geological variation as the DTC log along the studied interval, with a strong correlation coefficient (R<sup>2</sup>) of 0.97. Otherwise, the AI algorithms indicate a reliable performance with high accuracy (R<sup>2</sup>) and low values of root mean square error (R<sup>2</sup>∼0.96, RMSE∼0.1) for the first training. Compared with the first run, the second run is less accurate (R<sup>2</sup>∼0.8, RMSE∼0.26). Moreover, the AI-based model produced logs lacking the detailed variability of actual measurements while reducing prediction error and noting the high-frequency variation of the outputs, which may be due to the regularization and averaging effects of the algorithms.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106002"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mapping lithology and hydrothermal alteration zones in tropical environments remains a challenge due to the dense soil cover, the vegetation and the high cost of advanced methods. This study aims to discriminate volcanic formations and map hydrothermal alteration in the Nkondjock region using Sentinel-2 imagery, a rapid and cost-effective approach. Nkondjock, located in the Nyong-Bayomen domain of the Central African Fold Belt in Cameroon (CAFB), is underlain by rocks forming the Cameroon Line (CL). The visible, near-infrared (VNIR) and short-wave infrared (SWIR) bands of the Sentinel-2 sensor were used in this work. Image processing is based on band ratios, band combinations, principal component analysis (PCA) and supervised and unsupervised classifications. These techniques enable us to distinguish between basic and acidic volcanic rocks, as well as intrusive and metamorphic rocks. PCA confirms the delimitation of lithological units, and classification into basalts, basanites, tephrites, phonolites and trachytes, as well as the boundaries between volcanic, plutonic and metamorphic rocks. Principal component image and spectral ratio analysis are used to map iron oxides (B4/B3), hydroxylated (B12/B11 and B11/B8A), clay (B11/B5), and carbonate minerals (B11/B2). The resulting maps facilitate the exploration of hydrothermal deposits in the Nkondjock region, and more specifically in the Ndomgang, soho, Ntoumbé, Ndjingang, Mile, Male, Makita, Sahe, Nkongmalang, Matoube, Kouedjou, Tam and Bindjen areas. Validation by confusion matrix, field observations and laboratory analysis confirms the effectiveness of Sentinel-2 data for lithological discrimination and mineral prospecting in tropical and subtropical environments.
{"title":"Mapping lithological units and alteration minerals in volcanic rocks of Nkondjock, Littoral Region, Cameron using Sentinel-2 remote sensing satellite imagery and comprehensive fieldwork","authors":"Synthia Nguimatsia Tengomo , Rodolph Loïque Azefack Mbounou , Agnès Blandine Kamgang Tchuifong , Amin Beiranvand Pour , David Guimolaire Nkouathio","doi":"10.1016/j.jafrearsci.2026.106003","DOIUrl":"10.1016/j.jafrearsci.2026.106003","url":null,"abstract":"<div><div>Mapping lithology and hydrothermal alteration zones in tropical environments remains a challenge due to the dense soil cover, the vegetation and the high cost of advanced methods. This study aims to discriminate volcanic formations and map hydrothermal alteration in the Nkondjock region using Sentinel-2 imagery, a rapid and cost-effective approach. Nkondjock, located in the Nyong-Bayomen domain of the Central African Fold Belt in Cameroon (CAFB), is underlain by rocks forming the Cameroon Line (CL). The visible, near-infrared (VNIR) and short-wave infrared (SWIR) bands of the Sentinel-2 sensor were used in this work. Image processing is based on band ratios, band combinations, principal component analysis (PCA) and supervised and unsupervised classifications. These techniques enable us to distinguish between basic and acidic volcanic rocks, as well as intrusive and metamorphic rocks. PCA confirms the delimitation of lithological units, and classification into basalts, basanites, tephrites, phonolites and trachytes, as well as the boundaries between volcanic, plutonic and metamorphic rocks. Principal component image and spectral ratio analysis are used to map iron oxides (B4/B3), hydroxylated (B12/B11 and B11/B8A), clay (B11/B5), and carbonate minerals (B11/B2). The resulting maps facilitate the exploration of hydrothermal deposits in the Nkondjock region, and more specifically in the Ndomgang, soho, Ntoumbé, Ndjingang, Mile, Male, Makita, Sahe, Nkongmalang, Matoube, Kouedjou, Tam and Bindjen areas. Validation by confusion matrix, field observations and laboratory analysis confirms the effectiveness of Sentinel-2 data for lithological discrimination and mineral prospecting in tropical and subtropical environments.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106003"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jafrearsci.2026.106005
Bosy A. El-Haddad , Ahmed M. Youssef , Tawfiq M. Mahran , AbdelHammed A. El-Shater , Hamid Reza Pourghasemi
This study employed a sedimentological investigation and remote sensing techniques to reconstruct the geological progression of the Egyptian Nile in the west and southwest of Sohag City. A viable methodology for mapping the area was developed using “Landsat-Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager (OLI) images. Three processing techniques were applied, including principal component analysis (PCA), minimal noise fraction (MNF), and decoration stretch (DS) followed by a supervised classification, to map the area. The Katkut and Abu Retag formations were delineated and extracted from the adjacent units. A comprehensive field investigation was conducted to understand the lithological facies of these deposits, verify the remote sensing results, and construct a depositional model. The results revealed a diverse range of continental sediments and variations in depositional environments. These sediments represent two phases of Nile development, from the late Oligocene to the middle to late Miocene era. Our findings emphasized the significant role of paleoclimate, local and regional tectonics, and paleogeomorphology on the geological history of the study area. Climate indicators demonstrated a recurring pattern of climatic transformation, transitioning from humid and semiarid regions to dry conditions. The evolution of the region was significantly shaped by the Nubian Swell, the development of NW-trending grabens, and the hanging walls that linked fault segments, governing the Pre-Eonile and Eonile systems. Three distinct phases were identified in the history of provenance: sediment rich chert carbonates, quartz-rich deposits, and mixtures of detritus containing carbonates, quartz, and pieces of basement rock. These stages indicate shifts in the source location owing to the shifting tectonic activity. This research provides valuable insights and contributions into the Nile's evolution, the Nile's geological history, potential resource exploration, and offers a foundation for future research in the area.
{"title":"Mapping of the pre-Eonile - Eonile sediments using remote sensing technique and sedimentological investigation in the western desert of Egypt","authors":"Bosy A. El-Haddad , Ahmed M. Youssef , Tawfiq M. Mahran , AbdelHammed A. El-Shater , Hamid Reza Pourghasemi","doi":"10.1016/j.jafrearsci.2026.106005","DOIUrl":"10.1016/j.jafrearsci.2026.106005","url":null,"abstract":"<div><div>This study employed a sedimentological investigation and remote sensing techniques to reconstruct the geological progression of the Egyptian Nile in the west and southwest of Sohag City. A viable methodology for mapping the area was developed using “Landsat-Enhanced Thematic Mapper Plus (ETM<sup>+</sup>) and Operational Land Imager (OLI) images. Three processing techniques were applied, including principal component analysis (PCA), minimal noise fraction (MNF), and decoration stretch (DS) followed by a supervised classification, to map the area. The Katkut and Abu Retag formations were delineated and extracted from the adjacent units. A comprehensive field investigation was conducted to understand the lithological facies of these deposits, verify the remote sensing results, and construct a depositional model. The results revealed a diverse range of continental sediments and variations in depositional environments. These sediments represent two phases of Nile development, from the late Oligocene to the middle to late Miocene era. Our findings emphasized the significant role of paleoclimate, local and regional tectonics, and paleogeomorphology on the geological history of the study area. Climate indicators demonstrated a recurring pattern of climatic transformation, transitioning from humid and semiarid regions to dry conditions. The evolution of the region was significantly shaped by the Nubian Swell, the development of NW-trending grabens, and the hanging walls that linked fault segments, governing the Pre-Eonile and Eonile systems. Three distinct phases were identified in the history of provenance: sediment rich chert carbonates, quartz-rich deposits, and mixtures of detritus containing carbonates, quartz, and pieces of basement rock. These stages indicate shifts in the source location owing to the shifting tectonic activity. This research provides valuable insights and contributions into the Nile's evolution, the Nile's geological history, potential resource exploration, and offers a foundation for future research in the area.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106005"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jafrearsci.2026.106001
Alaaeddine Ait Ayad, Soufiane Maimouni, Yousra Morsli, Ahmed Fekri
Conventional lithological mapping techniques are often challenging and intricate, particularly in inaccessible areas. Integrating remote sensing and Machine Learning Algorithms (MLA) provides a robust and precise tool for interpreting geological structures. Exploiting remote sensing data using advanced MLA enhances lithological mapping through spectral classification. The objective of this research is to analyze and assess the effectiveness of ML methods: Support Vector Machine (SVM), Random Forest (RF), K-Nearest Neighbors (k-NN), Artificial Neural Network (ANN) and Maximum Likelihood Classifier (MLC) for lithological mapping by using ASTER data. Remote sensing data combined with machine learning (particularly SVM) can be an effective solution for detailed mapping of rocks with the same mineralogy but different grain sizes. Applying these techniques to the Sebt Brikiine pluton allowed for distinguishing three granitic facies and two units. The evaluation of these different methods and the comparison of their results have shown that the methods showed that the best overall accuracy of 97 % and a Kappa coefficient of 0.95 were achieved with the SVM approach. whereas the RF approach showed an overall accuracy of approximately 96 % with a Kappa coefficient of 0.93. Although the k-NN approach yielded an OA of around 92 % and a Kappa coefficient of 0.87, the ANN approach provided a lower overall accuracy of 83 % with a Kappa coefficient of 0.74 in comparison with other classification approaches. MLC provides the lowest overall accuracy value of 68 % and Kappa coefficient of 0.51. The results of this comparison study lead to the conclusion that SVM, as a supervised learning algorithm, is the most suitable and accurate technique for mapping granitic facies. It delimits a circumscribed SW granitic unit, composed of medium-grained granite surrounded by coarse-grained facies and overlain by frozen edges of fine-grained granite. This circumscribed structure cuts across an earlier NE unit composed of medium granite with vacuoles. These units are located in extensions along the lithospheric fault of the Western Meseta in late Variscan period of Morocco. This technique can be extended to the granitic bodies of the Variscan belt in Morocco, which are intrinsic to the main NE- and ENE-trending lithospheric faults.
{"title":"Advanced lithological mapping using ASTER data and machine learning: Sebt Brikiine pluton, Rehamna massif, Morocco","authors":"Alaaeddine Ait Ayad, Soufiane Maimouni, Yousra Morsli, Ahmed Fekri","doi":"10.1016/j.jafrearsci.2026.106001","DOIUrl":"10.1016/j.jafrearsci.2026.106001","url":null,"abstract":"<div><div>Conventional lithological mapping techniques are often challenging and intricate, particularly in inaccessible areas. Integrating remote sensing and Machine Learning Algorithms (MLA) provides a robust and precise tool for interpreting geological structures. Exploiting remote sensing data using advanced MLA enhances lithological mapping through spectral classification. The objective of this research is to analyze and assess the effectiveness of ML methods: Support Vector Machine (SVM), Random Forest (RF), K-Nearest Neighbors (k-NN), Artificial Neural Network (ANN) and Maximum Likelihood Classifier (MLC) for lithological mapping by using ASTER data. Remote sensing data combined with machine learning (particularly SVM) can be an effective solution for detailed mapping of rocks with the same mineralogy but different grain sizes. Applying these techniques to the Sebt Brikiine pluton allowed for distinguishing three granitic facies and two units. The evaluation of these different methods and the comparison of their results have shown that the methods showed that the best overall accuracy of 97 % and a Kappa coefficient of 0.95 were achieved with the SVM approach. whereas the RF approach showed an overall accuracy of approximately 96 % with a Kappa coefficient of 0.93. Although the k-NN approach yielded an OA of around 92 % and a Kappa coefficient of 0.87, the ANN approach provided a lower overall accuracy of 83 % with a Kappa coefficient of 0.74 in comparison with other classification approaches. MLC provides the lowest overall accuracy value of 68 % and Kappa coefficient of 0.51. The results of this comparison study lead to the conclusion that SVM, as a supervised learning algorithm, is the most suitable and accurate technique for mapping granitic facies. It delimits a circumscribed SW granitic unit, composed of medium-grained granite surrounded by coarse-grained facies and overlain by frozen edges of fine-grained granite. This circumscribed structure cuts across an earlier NE unit composed of medium granite with vacuoles. These units are located in extensions along the lithospheric fault of the Western Meseta in late Variscan period of Morocco. This technique can be extended to the granitic bodies of the Variscan belt in Morocco, which are intrinsic to the main NE- and ENE-trending lithospheric faults.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106001"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jafrearsci.2026.106000
D.R. Ferreira , M.B. Klausen , B.P. Von der Heyden , P. Le Roux
Renewed interest in the Tantalite Valley Complex has uncovered PGE-enriched magmatic sulphides. Despite this, little is known about the internal stratigraphy of the complex. This study aims to rectify this paucity of research by investigating the internal stratigraphy and architecture of the TVC. These aims have been achieved through field mapping, petrographic, geochemical, and isotopic studies from an extensive and representative sample set. These techniques have shed light on the magmatic evolution of the study site, and the complex is interpreted to be a composite of three to four nested intrusions. The nested intrusions are overwhelmingly mafic and are layered in nature, in contrast to earlier interpretations in the literature. Additionally, these intrusions have undergone limited differentiation, where geochemical evidence reveals cryptic layering reversals interpreted to reflect open system magmatic recharge. Isotopic evidence supports these interpretations and underpins an interplay involving time, magma replenishments, tectonism, and the establishment of new magma chambers that ultimately formed the complicated stratigraphy of the Tantalite Valley Complex. This study highlights the convoluted evolution of this intrusion during the Namaqua orogeny, having regional implications for the evolution of several similar intrusions in the surrounding area and indeed across global orogenies where mafic-ultramafic bodies exist.
{"title":"Magmatic architecture and evolution of the Mesoproterozoic nested layered mafic intrusions of the Tantalite Valley Complex, southern Namibia","authors":"D.R. Ferreira , M.B. Klausen , B.P. Von der Heyden , P. Le Roux","doi":"10.1016/j.jafrearsci.2026.106000","DOIUrl":"10.1016/j.jafrearsci.2026.106000","url":null,"abstract":"<div><div>Renewed interest in the Tantalite Valley Complex has uncovered PGE-enriched magmatic sulphides. Despite this, little is known about the internal stratigraphy of the complex. This study aims to rectify this paucity of research by investigating the internal stratigraphy and architecture of the TVC. These aims have been achieved through field mapping, petrographic, geochemical, and isotopic studies from an extensive and representative sample set. These techniques have shed light on the magmatic evolution of the study site, and the complex is interpreted to be a composite of three to four nested intrusions. The nested intrusions are overwhelmingly mafic and are layered in nature, in contrast to earlier interpretations in the literature. Additionally, these intrusions have undergone limited differentiation, where geochemical evidence reveals cryptic layering reversals interpreted to reflect open system magmatic recharge. Isotopic evidence supports these interpretations and underpins an interplay involving time, magma replenishments, tectonism, and the establishment of new magma chambers that ultimately formed the complicated stratigraphy of the Tantalite Valley Complex. This study highlights the convoluted evolution of this intrusion during the Namaqua orogeny, having regional implications for the evolution of several similar intrusions in the surrounding area and indeed across global orogenies where mafic-ultramafic bodies exist.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106000"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jafrearsci.2026.106006
Amina Wafik , Mohamed Ben massoude , Nahla Ntarmouchant , Hassan Admou , Reda Chatiby , Youssef Atif , Amin Beiranvand Pour
Banded Iron Formations (BIFs) were previously unrecognized within the Pan-African Anti-Atlas orogenic belt in Morocco. Detailed investigations of quartz-ferruginous formations within the Skouraz volcano-sedimentary complex, Central Anti-Atlas, have led to the reclassification of these iron-rich deposits from Oligistschist to BIFs. The study involved geological mapping, petrological and mineralogical analyses (SEM, ICP-AES, EPMA), confirming the characteristic banded structure and mineralogy typical of BIFs. Geochemical data reveal high SiO2, Fe2O3, and Ba contents consistent with Neoproterozoic BIFs, particularly of the Rapitan type, with a minimum Fe content of 15 %. These BIFs are hosted in the Skouraz metasedimentary clastic-carbonate complex, which experienced greenschist facies metamorphism and formed through hydrogenous and hydrothermal processes during the second magmatic event of the Assif n'Bougamane-Takroumt complex (760–700 Ma). Originating from Fe-shale and Fe-sand protoliths during a Cryogenian glaciation event, these formations are estimated to date from the late Lower Cryogenian to the early Upper Cryogenian, providing a rare and detailed record of Precambrian glacial and ocean redox conditions. The Skouraz area features thick glacial diamictites layered with BIFs, reflecting climatic fluctuations and hydrothermal influences. This study enhances understanding of Neoproterozoic iron formation and highlights the role of glaciation and tectonics in BIF genesis.
{"title":"Petrological and geochemical characteristics of the Skouraz banded iron formation in the Bou Azzer inlier, central Anti-Atlas, Morocco: Insights into geodynamic implications","authors":"Amina Wafik , Mohamed Ben massoude , Nahla Ntarmouchant , Hassan Admou , Reda Chatiby , Youssef Atif , Amin Beiranvand Pour","doi":"10.1016/j.jafrearsci.2026.106006","DOIUrl":"10.1016/j.jafrearsci.2026.106006","url":null,"abstract":"<div><div>Banded Iron Formations (BIFs) were previously unrecognized within the Pan-African Anti-Atlas orogenic belt in Morocco. Detailed investigations of quartz-ferruginous formations within the Skouraz volcano-sedimentary complex, Central Anti-Atlas, have led to the reclassification of these iron-rich deposits from Oligistschist to BIFs. The study involved geological mapping, petrological and mineralogical analyses (SEM, ICP-AES, EPMA), confirming the characteristic banded structure and mineralogy typical of BIFs. Geochemical data reveal high SiO<sub>2</sub>, Fe<sub>2</sub>O<sub>3</sub>, and Ba contents consistent with Neoproterozoic BIFs, particularly of the Rapitan type, with a minimum Fe content of 15 %. These BIFs are hosted in the Skouraz metasedimentary clastic-carbonate complex, which experienced greenschist facies metamorphism and formed through hydrogenous and hydrothermal processes during the second magmatic event of the Assif n'Bougamane-Takroumt complex (760–700 Ma). Originating from Fe-shale and Fe-sand protoliths during a Cryogenian glaciation event, these formations are estimated to date from the late Lower Cryogenian to the early Upper Cryogenian, providing a rare and detailed record of Precambrian glacial and ocean redox conditions. The Skouraz area features thick glacial diamictites layered with BIFs, reflecting climatic fluctuations and hydrothermal influences. This study enhances understanding of Neoproterozoic iron formation and highlights the role of glaciation and tectonics in BIF genesis.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106006"},"PeriodicalIF":2.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-03DOI: 10.1016/j.jafrearsci.2025.105992
Parisa GholamiZadeh , Mohammad Hossein Adabi , Abbas Sadeghi
The Sarvak Formation is one of the heavy oil reservoirs in the Zagros Orogenic Belt in southern Iran. This formation is primarily composed of the Late Albian-Turonian carbonates, with minor shales. This study focuses on the depositional facies, diagenetic history, and petrophysical properties, including porosity, permeability, and water saturation, of the Sarvak Formation integrated with wireline logs to evaluate the reservoir characterization and outline the primary controls on its significant heterogeneity. The reservoir quality is principally controlled by (1) Primary depositional texture and (2) subsequent diagenetic overprinting. The rudistic grain-supported facies, deposited in shallow, high-energy mid-ramp settings, inherently establish the highest quality zones. Conversely, mud-supported facies from inner/outer ramp environments show reduced quality. This primary control is significantly modified by secondary diagenetic processes—notably meteoric dissolution, dolomitization, and fracturing induced during burial—which collectively acted to enhance both porosity and permeability across the sequences. In the Coastal Fars sub-zone, the Sarvak Formation exhibits six third-order transgressive-regressive sequences. The integration of core data with wireline logs identified eight distinct Pore Facies (PFs) that dictate large-scale heterogeneity within this sequence stratigraphic framework. Critically, Pore Facies 2 (PF2), characterized by rudist and bioclastic grainstones/rudstones associated with reef/fore-reef environments, represents the optimum reservoir zone, displaying average porosity of 11.6 % and permeability of 21.37 md, primarily found beneath sequence boundaries (RSTs). In contrast, PFs 3, 5, 6, 7, and 8, located within Transgressive Systems Tracts (TSTs), function as moderate-low permeability units. The broader implication of this research is the development of a predictive model for reservoir spots. The results confirm that the most productive PFs (PF1, PF2, and PF4) are vertically associated with the upper sections of specific sequences (Sequence boundaries of Late Albian, Late Cenomanian, and Turonian). This stratigraphic framework provides a crucial predictive tool for enhanced reservoir characterization, suggesting that high-quality zones may thicken preferentially toward the northwest of the Coastal Fars sub-zone.
{"title":"Spatial heterogeneity of porosity and permeability in the Albian — Turonian Sarvak Formation, Coastal Fars, south of Iran","authors":"Parisa GholamiZadeh , Mohammad Hossein Adabi , Abbas Sadeghi","doi":"10.1016/j.jafrearsci.2025.105992","DOIUrl":"10.1016/j.jafrearsci.2025.105992","url":null,"abstract":"<div><div>The Sarvak Formation is one of the heavy oil reservoirs in the Zagros Orogenic Belt in southern Iran. This formation is primarily composed of the Late Albian-Turonian carbonates, with minor shales. This study focuses on the depositional facies, diagenetic history, and petrophysical properties, including porosity, permeability, and water saturation, of the Sarvak Formation integrated with wireline logs to evaluate the reservoir characterization and outline the primary controls on its significant heterogeneity. The reservoir quality is principally controlled by (1) Primary depositional texture and (2) subsequent diagenetic overprinting. The rudistic grain-supported facies, deposited in shallow, high-energy mid-ramp settings, inherently establish the highest quality zones. Conversely, mud-supported facies from inner/outer ramp environments show reduced quality. This primary control is significantly modified by secondary diagenetic processes—notably meteoric dissolution, dolomitization, and fracturing induced during burial—which collectively acted to enhance both porosity and permeability across the sequences. In the Coastal Fars sub-zone, the Sarvak Formation exhibits six third-order transgressive-regressive sequences. The integration of core data with wireline logs identified eight distinct Pore Facies (PFs) that dictate large-scale heterogeneity within this sequence stratigraphic framework. Critically, Pore Facies 2 (PF2), characterized by rudist and bioclastic grainstones/rudstones associated with reef/fore-reef environments, represents the optimum reservoir zone, displaying average porosity of 11.6 % and permeability of 21.37 md, primarily found beneath sequence boundaries (RSTs). In contrast, PFs 3, 5, 6, 7, and 8, located within Transgressive Systems Tracts (TSTs), function as moderate-low permeability units. The broader implication of this research is the development of a predictive model for reservoir spots. The results confirm that the most productive PFs (PF1, PF2, and PF4) are vertically associated with the upper sections of specific sequences (Sequence boundaries of Late Albian, Late Cenomanian, and Turonian). This stratigraphic framework provides a crucial predictive tool for enhanced reservoir characterization, suggesting that high-quality zones may thicken preferentially toward the northwest of the Coastal Fars sub-zone.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 105992"},"PeriodicalIF":2.2,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-03DOI: 10.1016/j.jafrearsci.2026.105998
Ana Maria Pinho Guina , José Augusto Guina , Filomena Anjos , Jorge Ferrão , Victoria Bell , Tito Horácio Fernandes
Ancient human food ways is a fundamental part of the history of humankind. Hominins’ evolution has paralleled major shifts such as the introduction of lithic devises, gain mastery over fire, cooking, fermentation, plant and animal domestication, which, in turn, have been associated with anatomical, physiological, cognitive, sociocultural, and behavioural shifts. A holistic understanding may shed light not only on how human diet evolved, but also on the mechanisms governing metabolism and prevalent metabolic syndromes in modern humankind. Food is essential for understanding human development, adaptation, environmental exploitation, cognition, technology, and survival, while adaptations to the habitat and lifestyle have led to changes in human genome from dietary transitions across hundreds of human generations. Ancient foods incorporate the complex milieu of phytonutrients in grains, native plants, mushrooms, fruits, legumes, nuts, honey, and seeds, being the nutritious building blocks of each heritage diet, essential for ensuring sustainable food security. Meat eating have played a major role mainly on brain size increase. What foods people ate in the past, how foods were prepared, and what does this disclose about daily lives, cultural values and social interactions, is a central data repository, and may give an indication of chronic disease prevention. The reconstruction of ancient diets is complex for many factors, including to the unpredictability of humans themselves. We address some cultural practices, dietary traditions, ancient diets and culinary practices, understanding the enormous variability among regional countries and the nutritional transition shift from hunter-gatherer societies to agricultural-based subsistence and present westernised diets. Integrating ancestral dietary wisdom does not necessarily mean strictly adhering to a primitive diet, but rather adopting core principles validated by modern science to reduce the risk of chronic diseases prevalent in modern society.
{"title":"Early human dietary heritage in Sub-Saharan Africa","authors":"Ana Maria Pinho Guina , José Augusto Guina , Filomena Anjos , Jorge Ferrão , Victoria Bell , Tito Horácio Fernandes","doi":"10.1016/j.jafrearsci.2026.105998","DOIUrl":"10.1016/j.jafrearsci.2026.105998","url":null,"abstract":"<div><div>Ancient human food ways is a fundamental part of the history of humankind. Hominins’ evolution has paralleled major shifts such as the introduction of lithic devises, gain mastery over fire, cooking, fermentation, plant and animal domestication, which, in turn, have been associated with anatomical, physiological, cognitive, sociocultural, and behavioural shifts. A holistic understanding may shed light not only on how human diet evolved, but also on the mechanisms governing metabolism and prevalent metabolic syndromes in modern humankind. Food is essential for understanding human development, adaptation, environmental exploitation, cognition, technology, and survival, while adaptations to the habitat and lifestyle have led to changes in human genome from dietary transitions across hundreds of human generations. Ancient foods incorporate the complex milieu of phytonutrients in grains, native plants, mushrooms, fruits, legumes, nuts, honey, and seeds, being the nutritious building blocks of each heritage diet, essential for ensuring sustainable food security. Meat eating have played a major role mainly on brain size increase. What foods people ate in the past, how foods were prepared, and what does this disclose about daily lives, cultural values and social interactions, is a central data repository, and may give an indication of chronic disease prevention. The reconstruction of ancient diets is complex for many factors, including to the unpredictability of humans themselves. We address some cultural practices, dietary traditions, ancient diets and culinary practices, understanding the enormous variability among regional countries and the nutritional transition shift from hunter-gatherer societies to agricultural-based subsistence and present westernised diets. Integrating ancestral dietary wisdom does not necessarily mean strictly adhering to a primitive diet, but rather adopting core principles validated by modern science to reduce the risk of chronic diseases prevalent in modern society.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 105998"},"PeriodicalIF":2.2,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Chtouka Plain, in central western Morocco, is facing a severe water crisis due to declining rainfall linked to climate change and increasing groundwater exploitation, particularly for agriculture. This situation has led to a significant drop in groundwater levels and growing concerns about seawater intrusion along the coast zone.
To address these issues, a multidisciplinary study intergrating geological, hydrogeological, and geophysical approaches was conducted. Remote sensing, GIS, and geophysical techniques such as Electrical Resistivity Tomography (ERT) and gravimetry were used to map lineaments, fault structures, and aquifer vulnerability. The main objective of this study is to identify the faults and lineaments affecting the area, as well as their contribution to groundwater circulation and aquifer recharge. The results reveal four dominant fault orientations (NE-SW, N-S, NW-SE, and E-W). Major structural features, such as the Western and Eastern Tiznit Faults, play a key role in controlling groundwater flow between deep and shallow aquifers. Indeed, the Cenomanian–Turonian aquifer, composed of fractured limestones and dolomites underlying Quaternary deposits, is identified as the main groundwater reservoir, offering high potential for sustainable water resource management.
{"title":"Structural study of the Chtouka Plain (Morocco) for hydrogeological implications: Insights from geological, remote sensing and geophysical data analysis","authors":"Sliman Hitouri , Ibtissam Rezouki , Mustapha Ikirri , Siham Aouzal , Mustapha Boujamaoui , Mohamed Abioui , Abdelouahed Essaied","doi":"10.1016/j.jafrearsci.2026.105997","DOIUrl":"10.1016/j.jafrearsci.2026.105997","url":null,"abstract":"<div><div>The Chtouka Plain, in central western Morocco, is facing a severe water crisis due to declining rainfall linked to climate change and increasing groundwater exploitation, particularly for agriculture. This situation has led to a significant drop in groundwater levels and growing concerns about seawater intrusion along the coast zone.</div><div>To address these issues, a multidisciplinary study intergrating geological, hydrogeological, and geophysical approaches was conducted. Remote sensing, GIS, and geophysical techniques such as Electrical Resistivity Tomography (ERT) and gravimetry were used to map lineaments, fault structures, and aquifer vulnerability. The main objective of this study is to identify the faults and lineaments affecting the area, as well as their contribution to groundwater circulation and aquifer recharge. The results reveal four dominant fault orientations (NE-SW, N-S, NW-SE, and E-W). Major structural features, such as the Western and Eastern Tiznit Faults, play a key role in controlling groundwater flow between deep and shallow aquifers. Indeed, the Cenomanian–Turonian aquifer, composed of fractured limestones and dolomites underlying Quaternary deposits, is identified as the main groundwater reservoir, offering high potential for sustainable water resource management.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 105997"},"PeriodicalIF":2.2,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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