Journal of African Earth Sciences最新文献

{"title":"Identification, genesis, and structural-gitological analysis of copper mineralization in the Middle Atlas, Morocco: integrating remote sensing with field investigations","authors":"Mohammed Laiche ,&nbsp;Youssef Drissi ,&nbsp;Saïd Hinaje ,&nbsp;Driss Yaagoub ,&nbsp;Mohamed El Fartati ,&nbsp;Youssef Ouahzizi ,&nbsp;Anas Laksir","doi":"10.1016/j.jafrearsci.2025.105949","DOIUrl":"10.1016/j.jafrearsci.2025.105949","url":null,"abstract":"<div><div>Copper mineralization in the Moroccan Atlas Mountains remains insufficiently characterized, particularly within the Middle Atlas, where the metallogenic framework and structural controls are still poorly constrained. Previous research has mainly focused on the better-documented Anti-Atlas and High Atlas provinces, leaving a significant knowledge gap concerning the geological and tectonic factors governing copper deposition in this orogenic belt. To address this gap, the present study applies an integrated and reproducible methodological framework that combines remote sensing analysis, structural interpretation, and field-based geological validation to evaluate the metallogenic potential of the Middle Atlas. Principal Component Analysis (PCA) was performed on Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data to extract major structural lineaments, while spectral band ratio techniques were employed to map hydrothermal alteration zones indicative of copper mineralization, including sericitic, argillic, propylitic, and ferruginous alterations. Through this integrated methodological framework, favorable zones for significant mineralization were accurately delineated, primarily along major tectonic structures. Field investigations confirmed the presence of copper mineralization occurring in two main morphological types: (i) vein-type mineralization hosted within fault zones and tension gashes, and (ii) stratiform mineralization within sedimentary layers interbedded with Triassic doleritic basalt flows. Structural analysis indicated that the mineralization is spatially and temporally associated with two principal tectonic phases: (i) a NW–SE to WNW–ESE extensional regime corresponding to the main mineralizing phase, and (ii) a NW–SE compressional phase responsible for the development of NNE–SSW sinistral and WNW–ESE dextral strike-slip faults, which locally remobilized earlier mineralized structures together with manganese occurrences. These tectonic activities resulted in the deformation of pre-existing mineralized structures, forming NW–SE-oriented tension gashes filled with quartz and traces of malachite. Petrographic and mineralogical analyses reveal a paragenetic sequence dominated by copper sulfides (chalcopyrite, chalcocite, bornite, and covellite), followed by secondary copper carbonates (malachite, azurite) and late-stage iron oxides (hematite, limonite), indicating a complex hydrothermal-supergene evolution. These results provide concrete insights to effectively guide mineral exploration in the ug.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105949"},"PeriodicalIF":2.2,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690723","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}

{"title":"Talc mineralization in the SW Fodikwan area, Red Sea Hills, NE Sudan: Geological and geochemical constraints","authors":"Alsir A.A. Alkhaleefa ,&nbsp;Talha M. Yousif ,&nbsp;Musab A.A. Hassan ,&nbsp;Khalid A. Elsayed Zeinelabdein","doi":"10.1016/j.jafrearsci.2025.105948","DOIUrl":"10.1016/j.jafrearsci.2025.105948","url":null,"abstract":"<div><div>Talc deposits found in the southwestern Fodikwan area of northeastern Sudan exhibit potential economic significance; nevertheless, their geological context, geochemical characteristics, and genesis remain inadequately defined. This study aims to elucidate the origin and formation mechanisms of these deposits, thereby facilitating the development of more effective exploration strategies. An integrated methodology was employed, comprising detailed geological mapping, petrographic investigations, and mineralogical and geochemical assessments utilizing X-ray diffraction (XRD) and X-ray fluorescence (XRF). The study area is characterized by basement rocks comprising a volcanic-sedimentary sequence that has been metamorphosed in the greenschist facies and intruded by syn-to late-orogenic microgranodiorite. Field and petrographic observations indicate that unaltered dolomitic marble predominates in areas distant from microgranodiorite contacts. Conversely, the contact zone between dolomitic marble and microgranodiorite presents a conducive environment for talc mineralization. Geochemical analyses reveal that SiO₂ and MgO are the dominant constituents, whereas CaO exhibits a decreasing trend as SiO₂ increases, reflecting the metamorphism of dolomitic marble into talc. Additionally, a noteworthy depletion of Al, La, Th, Cr, Ni, and Co in talc ores is inconsistent with a mafic or ultramafic protolith. The results suggest that the silica necessary for talc formation was derived from the adjacent microgranodiorite, with dolomitic marble acting as the primary protolith. Furthermore, the presence of quartz within the dolomitic marble may have provided the necessary silica for the formation of talc. This evidence supports a genetic model of contact metasomatism and has significant implications for regional talc exploration, particularly targeting the marble-microgranodiorite contact zones.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105948"},"PeriodicalIF":2.2,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690725","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}

{"title":"Spatiotemporal analysis of mining-induced land use and land cover changes in Zvishavane District of Zimbabwe","authors":"Elvis Batsirai Gumbo,&nbsp;Mark Makomborero Matsa,&nbsp;Pedzisai Kowe,&nbsp;John Hove","doi":"10.1016/j.jafrearsci.2025.105938","DOIUrl":"10.1016/j.jafrearsci.2025.105938","url":null,"abstract":"<div><div>Chrome mining plays a pivotal role in the local economy of Mhondongori Ward 5 and Mapirimira Ward 6 of Zvishavane District. However, it has also emerged as a dominant driver of land degradation in these mineral-rich rural communities. Despite the growing concern over environmental degradation, a gap persists in systematically quantifying mining footprints using remote sensing and GIS tools in Zimbabwe's rural areas. This study addresses the gap by integrating supervised classification of Landsat 5 Thematic Mapper (TM) and Landsat 8/9 Operational Land Imager (OLI) data using the Support Vector Machine (SVM) and Normalized Difference Vegetation Index (NDVI) time-series analysis in ArcMap 10.5. Further, the Binary Logistic Regression (BLR) was done using IBM Statistical Package for Social Sciences 25.0 (IBM SPSS 25.0) to evaluate land degradation extent and intensity. The analysis investigates the spatiotemporal patterns of mining-induced land use land cover (LULC) changes in these wards of Zvishavane District from 2000 to 2024 using geospatial techniques. Results reveal a dual transformation with spatial expansion and ecological entrenchment of chrome mining, prominent between 2000 and 2013 with continued consolidation up to 2024. Mining land increased from 0.2 km² to 1.8 km² whilst bareland and forest areas declined by 3.4 km² and 7.7 km², respectively. NDVI analysis consistently indicates lower vegetation health in mining zones compared to control areas with peak degradation observed post-2013. Regression outputs confirm mining as a more significant driver of land degradation than cultivation which is largely reactive and driven by survival needs. The study concludes that mining-induced land changes are non-cyclical and structurally displace traditional land uses, undermining ecological resilience and local livelihoods. It advocates for integrative land use planning frameworks that combine geospatial monitoring, socio-ecological restoration and inclusive governance to support Zimbabwe's land degradation neutrality and achievement of socio-ecological related sustainable development goals.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105938"},"PeriodicalIF":2.2,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621212","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}

{"title":"Tectono-sedimentary evolution of early syn-rift deposits in a hangingwall dip-slope setting, northern Duwi half-graben, red sea, Egypt","authors":"Tawfeek Mahran,&nbsp;Reham Youssef","doi":"10.1016/j.jafrearsci.2025.105943","DOIUrl":"10.1016/j.jafrearsci.2025.105943","url":null,"abstract":"<div><div>Studies comprehensively characterizing early syn-rift continental sedimentation in hangingwall settings are limited. To improve our understanding of how these deposits evolved, we must investigate the growth faults and related folds during rift-initiation. These structures significantly influenced the development of early syn-rift stratigraphic sequences along the strike and down the dip-slope. This study examines the stratal arrangement and sedimentology of the Late Oligocene-Early Miocene syn-rift lacustrine succession, which is consistently exposed along the hangingwall dip-slope strike in the northern Duwi half-graben sub-basin in the Red Sea Rift, Egypt. Detailed field-based description supported by petrographic investigations of the early syn-rift rocks enabled the discrimination of eight subassociations types that form three distinctive genetically-related facies associations deposited primarily in distal fluvial to lacustrine/palustrine carbonate-dominated environments. From a sequence stratigraphic perspective, three unconformity-bounded depositional sequences (<em>DSQ-1</em>, <em>DSQ-2</em>, and <em>DSQ-3</em>) have been identified, representing three successive phases of carbonate lake development. These sequences reflect transgressive-regressive cycles that record a major transition from open, shallow-lacustrine carbonate to fluvio-lacustrine carbonate, culminating in restricted lacustrine carbonate deposits. This study documents the interplay between hangingwall dip-slope tilting associated with growth segmented NW-SE-trending fault system, paleoclimate and provenance, proposing a new tectono-sedimentological model for rift initiation. The results of study have implications for other hangingwall dip-slopes in the Red Sea rift sub-basins.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105943"},"PeriodicalIF":2.2,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621196","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}

{"title":"Fluoride distribution in volcanic rocks of the Aluto volcano complex, Main Ethiopian Rift","authors":"Lioba Virchow ,&nbsp;Franziska Wilke ,&nbsp;Gezahegn Yirgu ,&nbsp;Thomas Neumann ,&nbsp;Simona Regenspurg","doi":"10.1016/j.jafrearsci.2025.105946","DOIUrl":"10.1016/j.jafrearsci.2025.105946","url":null,"abstract":"<div><div>High fluoride in groundwaters of the Main Ethiopian Rift is of geogenic origin. Although the involvement of volcanic rocks in fluoride enrichment is well documented, the specific mineralogical sources and dissolution mechanisms remain incompletely understood. This study characterized the mineralogical sources of fluoride in volcanic rocks of the Aluto volcano complex, identifying the specific mineral phases and their fluoride concentration that control fluoride availability in volcanic aquifer systems. Pyrohydrolysis was employed for precise fluoride determination, while X-ray fluorescence and electron microprobe analyses enabled phase-specific fluoride distribution and quantification of fluoride-bearing minerals. Water-rock leaching experiments were performed to quantify fluoride release and characterize associated ion dissolution patterns for mineral phase identification. The study shows that: (1) The younger volcanic deposits like pumice and obsidian generally contain high fluoride concentrations of up to 0.32 wt%, while the older ignimbrites show lower concentrations between 0.11 and 0.15 wt%. (2) Fluoride behaves as an incompatible element in the post-caldera rocks showing strong linear correlations with other incompatible elements such as Zr, Nb, and Y (R² &gt; 0.98). (3) Microprobe analyses of thin sections indicate that fluoride is incorporated into the glassy rock matrix, into apatite, and into the sodium amphibole riebeckite (the latter two occur only as accessory minerals). Mass calculations reveal that the largest proportion of fluoride is bound in the fine-grained matrix, as this phase represents 40 to 100 wt% of each rock sample. Thus, volcanic glass – particularly pumice – and glass-rich rocks have the highest potential to release fluoride, indicating that this phase controls fluoride availability in the rift groundwater system.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105946"},"PeriodicalIF":2.2,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690724","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}

{"title":"Mineralogical and morphological characteristics of Mn oxide phases in terrestrial ferromanganese deposits: A case study of wad and nodules from the Highveld region, North-West Province of South Africa","authors":"Benedict Kinshasa Pharoe ,&nbsp;Irina Mikhailovna Gembitskaya ,&nbsp;Alexandr Nikolaevich Evdokimov ,&nbsp;Natalia Ivanovna Vorontsova ,&nbsp;Christopher Baiyegunhi ,&nbsp;Sergei Alexandrovich Voropaev","doi":"10.1016/j.jafrearsci.2025.105945","DOIUrl":"10.1016/j.jafrearsci.2025.105945","url":null,"abstract":"<div><div>Fe-Mn nodules and crusts in terrestrial environments are predominantly associated with well-developed lateritic soil profiles. In this study, we report on the mineralogical and chemical characteristics of terrestrial Fe-Mn nodules from the North-West Manganese Deposit in South Africa. The primary objective is to characterize mineral associations, ore paragenetic sequences, morphologies, formation conditions, and chemical composition, with particular emphasis on the composition of Mn and strategic metals (i.e., Ni, Co, Cu, Ba, etc.). The distribution of these metals and their respective Mn oxide host phases was evaluated. To achieve the study's objectives, an integrated analytical approach using optical microscopy, High-Resolution Scanning Electron Microscopy with Energy-Dispersive Spectroscopy, X-ray Powder Diffraction, and Inductively Coupled Plasma Mass Spectrometry was used to investigate the ore micro-morphologies, microstructural textures, and modes of mineral occurrences and associations. Based on microscopic examinations and analytical data, Fe–Mn nodules display characteristic ore textures and morphologies, including botryoidal, colloform banding, and dendritic to radial-acicular forms, typical of cryptomelane, romanechite, hollandite, and lithiophorite. The gangue assemblage comprises detrital quartz and clay mica, which are mainly associated with early Mn oxide phases, whereas detrital zircon and ilmenite are confined to the clay-rich matrix. Lithiophorite was identified as the main host for Ni, Cu, and Co. Ba enrichment is associated with romanechite, while Nb and Ti are associated with ilmenite grains. The ore mineral paragenetic sequence revealed manganite and vernadite as the early phases to precipitate, followed by pyrolusite, cryptomelane, and romanechite, with lithiophorite representing the latest stage of mineragenesis. The presence of distinct Ce and Eu anomalies suggests that Fe-Mn nodules were formed through hydrogenetic processes.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105945"},"PeriodicalIF":2.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621211","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}

{"title":"Post-Variscan Ore occurrence from the Middle Atlas of Morocco: An example of Riedel brittle shear-related lead-rich sulfide veins","authors":"Ayoub Aabi ,&nbsp;Abdellatif Aarab ,&nbsp;Mohammed Amine Nguidi ,&nbsp;Youness Ahmed Laaziz ,&nbsp;Abdellah Nait Bba ,&nbsp;Younes Hejja ,&nbsp;Samir Samaoui ,&nbsp;Abdelhakim Jilali ,&nbsp;Lahssen Baidder","doi":"10.1016/j.jafrearsci.2025.105914","DOIUrl":"10.1016/j.jafrearsci.2025.105914","url":null,"abstract":"<div><div>The Tizi n'Oubadou ore occurrence, studied here for the first time, is hosted within the lower Liassic limestones of the Imouzzer-Marmoucha syncline located in the central part of the Middle Atlas belt (Morocco). Mineralization is generally lead-bearing, hosted either in calcite bodies and/or directly embedded in the hosting rocks. In this study, we propose an integrated approach that combines portable X-ray fluorescence (pXRF) geochemistry, electrical resistivity tomography (ERT), and field-based structural analysis to assess the geometric and depth features of mineralized structures and gain insights into their tectonic control. Structural mapping depicts a network of mineralized sulfide veins and veinlets sheltered within NNW-SSE to NNE-SSW dextral oblique-slip faults which acted as a P-brittle/Riedel shear, i.e., <em>Filon Principal</em>, locally displaying a horsetail splay pattern. The mineralization in multi-scale veins is organized en-echelon with a particular tension gash or pull-apart geometry. These structures appear to be associated with the Tizi n'Oubadou dextral strike-slip fault, which is interpreted as R′-Riedel brittle-shear and hints at a WSW-ENE shortening direction, previously linked regionally to ante-Cretaceous deformation. pXRF spectroscopy analyses reveal a Pb-dominated paragenesis (i.e., galena) with variable Mn, V, and Cd enrichments, reflecting hydrothermal alteration and interaction with the carbonate-argillaceous host rocks. ERT geophysical data show that Lead-sulfide bodies are concentrated beyond 26 m depth, suggesting promising economic potential.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105914"},"PeriodicalIF":2.2,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621197","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}

{"title":"An evaluation of spatial and temporal variations of land surface temperature in Biskra, Algeria using remote sensing and GIS","authors":"Zohra Abdelkrim ,&nbsp;Saeid Eslamian","doi":"10.1016/j.jafrearsci.2025.105942","DOIUrl":"10.1016/j.jafrearsci.2025.105942","url":null,"abstract":"<div><div>Urban heat stress in semi-arid Algerian cities, such as Biskra, remains insufficiently studied. Investigating its spatial and temporal dynamics through integrated RS and GIS approaches is crucial for advancing sustainable urban planning and climate adaptation strategies.</div><div>This study aims to analyze the spatial and temporal variations in land surface temperature (LST) between 2011 and 2022 in Biskra, Algeria, using Remote Sensing (RS) and Geographic Information Systems (GIS) techniques. It further seeks to identify the zones most affected by elevated LST and to examine their relationship with vegetation, built-up, and water indices (NDVI, NDBI, NDWI).</div><div>The results reveal significant seasonal and decadal variations in land surface temperature (LST). During the summer months, LST exceeded 45 °C in several urban zones, reflecting strong heat accumulation and limited vegetation cover. In contrast, cooler months recorded temperatures below 20 °C, associated with higher vegetation and water presence, indicating improved ecological quality. Overall, the findings highlight how urban expansion and seasonal variability have intensified heat stress and degraded environmental conditions in Biskra semi-arid context.</div><div>The analysis reveals marked seasonal and decadal variations in urban heat across Biskra, with higher LST, intensified Surface Urban Heat Island (SUHI), and lower Urban Thermal Field Variance Index (UTFVI) values indicating pronounced heat stress and reduced ecological quality during summer, contrasted by cooler and more balanced conditions in other seasons. These results emphasize the impact of urban expansion and seasonal variability on thermal stress and the vulnerability of Biskra urban environment, highlighting the need for vegetation-oriented and sustainable urban planning. Future research should employ higher-resolution data and predictive modeling to better understand urban thermal dynamics under climate change.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105942"},"PeriodicalIF":2.2,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735098","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}

{"title":"Insights into L4 ordinary chondrites from the Gueltat Zemmour fall, Morocco: Modal mineralogy, chondrule characteristics, and magnetic signatures","authors":"E. El Hachimi ,&nbsp;H. Chennaoui Aoudjehane ,&nbsp;S. Russell ,&nbsp;B. Devouard ,&nbsp;J. Gattacceca","doi":"10.1016/j.jafrearsci.2025.105944","DOIUrl":"10.1016/j.jafrearsci.2025.105944","url":null,"abstract":"<div><div>The Gueltat Zemmour meteorite, an L4 ordinary chondrite that fell in southern Morocco on 21 August 2018, was investigated through petrographic, mineralogical, geochemical, and magnetic analyses. X-ray diffraction indicates a modal composition dominated by forsteritic olivine (39.7(4) weight %), enstatite (32.4(3) %), plagioclase (7.3(1) %), troilite (3.7(1) %), and Fe–Ni metal phases (16.9 %, kamacite-dominated). Chondrules represent ∼82 % of the surface area, with porphyritic olivine–pyroxene and porphyritic olivine as the dominant types, and an average diameter of ∼500 μm. Gamma spectrometry confirmed the presence of short-lived cosmogenic radionuclides (e.g., ⁷Be, ²²Na, ²⁶Al, ⁴⁸V), with a ²²Na/²⁶Al activity ratio consistent with a recent fall. Magnetic hysteresis properties and the preservation of tetrataenite in cloudy zone textures indicate slow cooling during parent-body metamorphism. The sulfide assemblage, dominated by troilite with rare pentlandite, combined with Fe/S (∼0.98) and Fe_ox/Si (∼0.36) ratios, reflects reducing redox conditions near the iron–wüstite buffer and minimal secondary alteration. These integrated results confirm the classification of Gueltat Zemmour as an equilibrated L4 chondrite and provide new insights into the thermal history and redox state of L-group parent bodies, contributing to a broader understanding of the early evolution of ordinary chondrites.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105944"},"PeriodicalIF":2.2,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621210","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}

{"title":"Magnetic signatures and modeling of the Late Ediacaran dyke swarm in the central Saghro massif (Eastern Anti-Atlas, Morocco)","authors":"Ahmed Baamar ,&nbsp;Ezzoura Errami ,&nbsp;Brahim Karaoui ,&nbsp;Mourad Essalhi ,&nbsp;Mostapha Bouzekraoui ,&nbsp;Mourad Guernouche ,&nbsp;Said Haidatte ,&nbsp;Abderrahman Ben Ichou ,&nbsp;Zakarya Yajioui ,&nbsp;Hasna Er-raqqady","doi":"10.1016/j.jafrearsci.2025.105937","DOIUrl":"10.1016/j.jafrearsci.2025.105937","url":null,"abstract":"<div><div>The Central Part of the Saghro massif (CPSM), located in the Eastern Anti-Atlas, is characterized by a significant dyke swarm. These dykes remain insufficiently characterized from a geophysical perspective. The aim of this study is to apply a geophysical approach based on the ground magnetic method in order to better understanding the CPSM dyke swarm, as well as their host rocks. To achieve this objective, the magnetic data were subjected to a series of processing operations, including various filters and transformations. The qualitative analysis of the pole-reduced data reveals a strong correlation between the observed magnetic anomalies and the distribution of outcropping dykes in the metasedimentary basement of the Saghro Group and the volcano-sedimentary series of the Ouarzazate Supergroup. These anomalies are manifested by variations in magnetic intensity that follow the orientation of the dyke swarm mapped on surface, confirming their distinct magnetic signature. Complementary analysis of the magnetic data identified magnetic lineaments consistent with the surface mapped dykes. These lineaments appear as elongated anomalies reflecting the presence of continuous magnetic structures in the subsurface. In addition, the estimated depths of anomalous sources, obtained by Euler deconvolution from ground magnetic data, reveal values of up to 1000 m. Complementing the qualitative data analysis, a quantitative interpretation using 2D and 3D modeling was applied to the high-amplitude anomalies associated with the dyke's zones. The results obtained indicate that dykes correspond to sub-vertical structures, deeply rooted beyond 3 km.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"234 ","pages":"Article 105937"},"PeriodicalIF":2.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577571","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}