Journal of African Earth Sciences最新文献

{"title":"Analyzing sediment accumulation rates of the upper cretaceous Sarvak Formation based on well logging data in a cyclostratigraphic framework, southwestern Zagros Basin, Iran","authors":"Asbar Abbasi ,&nbsp;Ali Kadkhodaie ,&nbsp;Rahim Mahari ,&nbsp;Reza Moussavi-Harami","doi":"10.1016/j.jafrearsci.2025.105869","DOIUrl":"10.1016/j.jafrearsci.2025.105869","url":null,"abstract":"<div><div>Carbonate Sarvak Formation is considered as one of the productive oil reservoir units in Dezful embayment of the Zagros Basin. The current study focuses on the cyclostratigraphic analysis of the Sarvak Formation by using evolutionary spectral analysis approaches of fast Fourier transform (FFT) spectrogram combined with wavelet transform (WT) scalogram and multi-Taper Method (MTM) periodogram. The Multi-Taper Method (MTM) periodogram utilized in this study to detect the Milankovitch cycles in the Sarvak Formation. In addition, the power spectrum of spectral gamma-ray and formation density (RHOB) logs, based on evolutionary FFT and WT Scalograms indicate strong astronomical signals of the Milankovitch cycles (E, e, O, P) in three wells of the Anaran block. Using the new approaches of evolutionary correlation coefficient and evolutionary significance levels, variations in sediment accumulation rates during deposition of the Sarvak Formation were compared in wells A-C. The minimum and maximum amount of sediment accumulation in the upper Sarvak Formation in the studied wells are estimated to be approximately 2 cm/kyr and 5.2 cm/kyr, respectively. According to spectral powers observed in the evolutionary correlation coefficient spectrogram, the sedimentation of the upper Sarvak Formation in well C was mostly influenced by the long-eccentricity cycle (E); on the contrary and based on the observed spectral powers, the sedimentation of the upper Sarvak Formation in wells A and B is mostly influenced by Obliquity (O) and long-eccentricity cycle (E). The contribution of other cycles is insignificant compared to E and O.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105869"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222097","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":"Modeling of rainfall-runoff and flooding using HEC-HMS model through GIS in an arid environment: A case study in the Safaga Valley basin, West Safaga city, Egypt","authors":"Ali Hagras","doi":"10.1016/j.jafrearsci.2025.105867","DOIUrl":"10.1016/j.jafrearsci.2025.105867","url":null,"abstract":"<div><div>Reliable forecasts of rainfall-runoff are crucial for reducing flood risks. Furthermore, the risk of such floods can be prevented and reduced with the use of appropriate modeling. So, accurate runoff calculation is regarded as necessary for rainfall-runoff modeling. However, the lack of runoff measurements in watersheds is considered a big obstacle in many developing countries. So, this study uses an uncalibrated model based on established physical parameters. In Egypt, there are no monitoring field measurements for every watershed. Hence, the statistical distributions were adopted for the approximate estimation of rainfall depth at the meteorological station that affects the research area for various return periods and created an intensity duration frequency curve (IDF) in the return periods (25-50-100 years) in the Safaga Valley Basin. In the present study, the HEC-HMS model was used to create a runoff simulation in the Safaga Valley Basin. Also, the SCS curve number method, SCS unit hydrograph method, as a transform method was applied to simulate the hydrological processes. Also, assessing the study's findings by carrying out a field visit in the Safaga Valley Basin. The primary goal of this study is hydrological modeling of rainfall-runoff and Flooding in the Safaga Valley Basin applied the HEC-HMS Model through GIS environment to calculate the peak discharges, direct runoff volume and create hydrographs in the return periods of the sub-basins in the Safaga Valley Basin. Results showed result of the modeling in the return periods of the sub-basins in the Safaga Valley Basin where the total peak discharge in return period 100 years is 698.4 (m³/s) and sub-basin 7 is the largest peak discharge in return period 100 years where reached 137.5 (m³/s) and the total discharge volume in return period 100 years is 12288.5 (1000m³) and sub-basin 7 is the largest discharge volume in return period 100 years where reached 3050.2 (1000m³). In this regard, a flash flood risk assessment of the Safaga Valley sub-basins identified five possible hazards: very low, low, moderate, high, and very high. In addition, the finding shows that the hydrodynamic hazard is largest (High and Very high) in the SB2, SB3, SB4, and SB6 subbasins. In recent decades, the study area has seen devastating flash floods, which have had a significant impact on infrastructure, livelihoods, and human lives. So, this study recommended emphasizing these regions as top objectives for future flood mitigation strategies. The results demonstrate that the developed HEC-HMS model provides a crucial tool for sustainable land use planning and the design of flood protection infrastructure in the Safaga Valley Basin.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105867"},"PeriodicalIF":2.2,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222096","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":"Harnessing Variational Autoencoders and self-organising maps for groundwater contamination assessment in peri-urban Ghana","authors":"Portia Annabelle Opoku ,&nbsp;Raymond Webrah Kazapoe ,&nbsp;Noah Kwaku Baah ,&nbsp;Abass Gibrilla ,&nbsp;Geophrey K. Anornu ,&nbsp;Nana Kobea Bonso","doi":"10.1016/j.jafrearsci.2025.105866","DOIUrl":"10.1016/j.jafrearsci.2025.105866","url":null,"abstract":"<div><div>Although advanced machine learning models have demonstrated considerable potential for environmental monitoring, their application to assessing groundwater contamination in Ghana's peri-urban areas remains inadequately explored and poorly understood. To bridge this gap, this study aimed to apply advanced non-linear machine learning techniques, specifically Variational Autoencoders (VAEs) and Self-Organising Maps (SOMs), to analyse groundwater contaminants in south-eastern Ghana. The study examines intricate relationships and patterns among various pollutants to provide a comprehensive evaluation of groundwater quality. All the physicochemical parameters evaluated fell within the WHO guideline values. The VAE and SOM analyses confirm dual-source controls on groundwater chemistry in the Birimian terrains, involving both natural geogenic inputs from silicate and mafic lithologies and anthropogenic impacts from settlements. Inverse loadings across latent dimensions captured spatial heterogeneity, separating lithology-driven variables (e.g., Na⁺, Ca²⁺, EC) from pollution markers (e.g., NO₃⁻, Cl⁻). SOM clustering further distinguished zones of minimal human influence from areas with localised contamination, such as Pb hotspots and elevated EC and salinity linked to mineralisation or saline intrusion. Scattered peaks in F⁻ and Cl⁻ suggested episodic anthropogenic inputs. The results reveal notable disparities in machine learning model performance based on target variable features; the Nitrate Pollution Index (NPI) yielded a Test R² of 0.983, indicating superior predictive accuracy. Conversely, challenges with the Fluoride Pollution Index (FPI) and Pollution Index of Groundwater (PIG) exposed limitations due to unmeasured geological factors and low variability. We propose a data-driven, scalable diagnostic tool for monitoring water quality that can be integrated into national frameworks. This tool has implications for Sub-Saharan Africa and other regions similarly affected.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105866"},"PeriodicalIF":2.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222098","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":"Application of remote sensing, GIS, thermal anomalies and piezometric data in detecting potential geothermal zones, Essaouira basin (southwest Morocco)","authors":"Sabah Ben Elhamdi ,&nbsp;Abdelhalim Tabit ,&nbsp;Ahmed Algouti ,&nbsp;Chaima Ben Tabet ,&nbsp;Khadija Oudour ,&nbsp;Rabia Benaddi","doi":"10.1016/j.jafrearsci.2025.105861","DOIUrl":"10.1016/j.jafrearsci.2025.105861","url":null,"abstract":"<div><div>The Essaouira basin, situated in the western High Atlas Mountains in southwestern Morocco, boasts significant geothermal potential which remains largely unexplored. While the area is promising, the precise geothermal zones have not yet been mapped and the available resources remain poorly assessed. This study takes an integrated geospatial approach, combining remote sensing, GIS, piezometric data and fuzzy logic, in order to identify and delineate promising geothermal zones. Three key parameters were considered: areas of high permeability (derived from structural lineaments mapped from Landsat 8 PCA1 and the Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM)), surface temperature anomalies (LST) extracted from nine Landsat 8 TIRS scenes processed via Google Earth Engine, and low-to-medium piezometric gradients determined from field measurements. Superimposing these datasets revealed three major target areas: one near Bouabout, one near Bouzemmour, and one in the south-west between Aqesri, Tamri, and Ain Skhouna. Field validation confirmed the consistency of the results. Beyond identifying potential sites, this study proposes a robust, transferable methodology for geothermal prospecting in basins with complex structures. This contributes to sustainable energy planning in Morocco and similar geotectonic contexts.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105861"},"PeriodicalIF":2.2,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220930","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":"Pyrometasomatic mineralisation of Amensif Cu-Pb-Zn (Ag-Au) distal skarn deposit, Western high Atlas, Morocco: Insights from paragenetic evolution, mineral chemistry, and fluid inclusions","authors":"Ilyasse Loudaoued ,&nbsp;Mohamed Aissa ,&nbsp;Ahmed Touil ,&nbsp;Mohamed Hibti ,&nbsp;Hamid Zaidi ,&nbsp;Muhammad Souiri ,&nbsp;Mohamed Ait Addi ,&nbsp;Namık Aysal ,&nbsp;Isak Yilmaz","doi":"10.1016/j.jafrearsci.2025.105862","DOIUrl":"10.1016/j.jafrearsci.2025.105862","url":null,"abstract":"<div><div>The polymetallic Cu–Pb–Zn (Ag-Au) deposit of Amensif is represented by distal skarn and quartz-barite-carbonate vein structures. It is located in the northern part of the Western High Atlas and 5 km southwest of the famous Azegour Mo-Cu-W mine. The Amensif deposit is hosted in Lower Cambrian volcanoclastic-carbonate sequences, intruded by rhyolitic, andesitic and dacitic dykes and sills.</div><div>Based on field observations and mineralogical research, a comparative study of the two ore bodies (skarns and veins) was carried out. In the skarn, two main paragenetic stages can be distinguished: (i) prograde skarn and (ii) retrograde stage. The prograde stage was further subdivided into early prograde stage with wollastonite and diopside relics, which are rather discrete, and the late prograde stage, mainly with andradite, grandite garnet and hedenbergite. Based on mineral chemistry from the late prograde stage, garnet compositions evolve from andradite (And_83.97-99.19 Grs_0.00-15.20 Sps_0.41-2.01 Prp_0-0.19) to grandite garnet (And_34.14-65.56 Grs_30.62-64.56 Sps_0.72-6.05 Prp_0-0.16), in association with hedenbergite (Hd_86.83-93.23 Di_1.3-6.54 Jo_0.2-11.9), this evolution indicate a “strongly reduced” or “moderately reduced” condition with low ƒO₂. The retrograde skarn stage is divided into two sub-stages: (1) retrograde stage I, marked by the deposition of the main alteration minerals (e.g., tremolite, actinolite, epidote, quartz I, calcite I and barite) and sulfides I; and retrograde stage II, characterised by quartz and calcite vein-veinlets associated with sulfides II, electrum and Bi-Ag-sulfosalts. The chemistry of garnet and pyroxene supports classification of the Amensif skarn as a Cu-Zn-Fe skarn.</div><div>Fluid inclusions from garnets (prograde skarn stage), display high homogenisation temperatures and salinities (468.3–586 °C; 8.27 to 31.6 wt%. NaCl equiv.). By contrast, fluid inclusions associated with quartz I, calcite I and barite (early retrograde stage) record high to medium homogenisation temperatures (300.2–547.2 °C; 8 to 34.29 wt%. NaCl equiv.) for primary fluid I, and low homogenisation temperatures (171.3–288.7 °C) with same salinities for secondary fluid II. The decrease suggest that cooling and mixture are the main mechanisms of ore deposition.</div><div>The striking similarity between the silicate and sulfide mineralisation in the retrograde skarn and the vein structures, both in terms of mineralogy and fluid characteristics, suggests a genetic relationship between these two mineralised bodies.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105862"},"PeriodicalIF":2.2,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155647","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":"Late Stenian–Tonian magmatic signatures and provenance of metasedimentary rocks from the Deng-Deng area, East Cameroon","authors":"Donald Hermann Fossi ,&nbsp;Jonas Didero Takodjou Wambo ,&nbsp;Evine Laure Tanko Njiosseu ,&nbsp;Patrick Ayonta Kenne ,&nbsp;Sylvestre Ganno ,&nbsp;Jean Paul Nzenti","doi":"10.1016/j.jafrearsci.2025.105859","DOIUrl":"10.1016/j.jafrearsci.2025.105859","url":null,"abstract":"<div><div>The Deng-Deng metasedimentary rocks crop out in the central domain of the Central African Fold Belt (CAFB), Cameroon. Field investigations and petrography reveal garnet-biotite and calc-silicate gneisses, metamorphosed under amphibolite to granulite-facies conditions. Their Chemical Index of Alteration values range from 30.61 to 55.50, suggesting weak chemical weathering under dry and cold paleoclimatic conditions, while Index of Compositional Variability values (1.03–1.90) indicate immature sediments. Provenance indicators including high Zr/Sc ratios and element am ratios such as Th/Co and La/sc, suggest derivation from felsic source rocks and varying degrees of sedimentary reworking. Tectonic setting discrimination diagrams, based on major, trace, and REE elements, point to a continental arc depositional environment. The detrital zircon age spectrum highlights two main magmatic age peaks ca. 966 Ma and ca. 797 Ma, respectively, and a maximum depositional age of 673 ± 5 Ma. These new data provide evidence of late Stenian to Tonian (ca. 929–1024 Ma) magmatism in the CAFB and reworking during the Cryogenian–Ediacaran.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105859"},"PeriodicalIF":2.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155646","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":"Interpretation of seismic data and 3D structural and property modeling of siliciclastic Pliocene reservoirs in the Denise Field (eastern Nile delta Offshore): Insights for reservoir architecture and assessment","authors":"Mohamed Fathy ,&nbsp;Hatem E. Semary ,&nbsp;Mohamed Mosaad ,&nbsp;Anis Ben Ghorbal ,&nbsp;Amer A. Shehata","doi":"10.1016/j.jafrearsci.2025.105860","DOIUrl":"10.1016/j.jafrearsci.2025.105860","url":null,"abstract":"<div><div>This study integrates seismic interpretation and 3D structural and petrophysical modeling to characterize the Pliocene siliciclastic reservoirs of the Denise Field in the offshore Eastern Nile Delta, focusing on reservoir geometry, spatial distribution, and quality assessment. Seismic interpretation reveals a complex structural framework dominated by E-W trending growth faults (F1–F6) linked to Jurassic crustal extension, alongside NNE-SSW trending Rosetta faults associated with transpressional movement. A prominent rollover anticline and gas chimneys further influence hydrocarbon migration and accumulation. Petrophysical evaluation of the Kafr El Sheikh Formation identifies three key reservoir units: Pre U. Denise S.S., U. Denise S.S., and L. Denise S.S. The U. Denise S.S. unit, the primary reservoir, exhibits high porosity (15–30 %) and variable water saturation (20–42 %), with net pay thicknesses ranging from 52 to 130 m. The L. Denise S.S. unit shows consistent high porosity (17–32 %) but higher water saturation (30–40 %), while the Pre U. Denise S.S. unit is limited in distribution, with moderate porosity (15–35 %). 3D structural modeling highlights fault-controlled horst and graben structures, with sealing faults (F2, F3, F5) potentially compartmentalizing the reservoir. Facies modeling indicates NW-SE trending sand bodies, with the U. Denise S.S. unit exhibiting the highest sand content. Petrophysical modeling reveals strong porosity-permeability correlations, with gas-bearing zones concentrated in high-porosity regions. The study identifies the northwestern channel trend as the most favorable reservoir zone, while increased shale content and water saturation degrade reservoir quality in the central basin trend. These findings provide critical insights for reservoir development and future exploration in the Denise Field. Moreover, these results underscore the critical control of seismic interpretation and reservoir modelling on reservoir distribution and quality. These methodologies and findings provide a transferable framework with broad international significance, offering essential insights for future exploration targeting in analogous settings worldwide.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105860"},"PeriodicalIF":2.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155645","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":"Characterizing the origins of groundwater salinity in the Mio-Plio-Quaternary aquifers of the middle eastern Cheliff basin in northwest Algeria using electrical resistivity techniques","authors":"Rachid Ahmed Rahmani ,&nbsp;Aziez Zeddouri ,&nbsp;Lonnie G. Kennedy ,&nbsp;Mawloud Hadjadj ,&nbsp;Nabil Brahmia ,&nbsp;Mohamed Salah Belksier","doi":"10.1016/j.jafrearsci.2025.105858","DOIUrl":"10.1016/j.jafrearsci.2025.105858","url":null,"abstract":"<div><div>The climate of northwestern Algeria's Middle Eastern Cheliff basin is mostly semi-arid. The main source of water for the municipal and private sectors is the shallow Mio-Plio-Quaternary groundwater system. However, deep saltwater intrusion has caused it to become significantly salinized in recent decades. Determining the lateral extent of the saltwater interface and determining the source of groundwater salinity are the goals of this study. This was achieved by conducting 30 vertical electrical borehole (VES) experiments and 8 electrical resistivity tomography (ERT) profiles. Fifty groundwater sampling locations were selected for in situ physical component analysis in order to evaluate the salinity of the groundwater. Furthermore, a total of 39 soil samples were taken from 39 different places. Each sample's soil 1:5 extracts were examined to determine the salinity of the soil.</div><div>The groundwater electrical conductivity geographical distribution shows extremely high values, increasing westward from 1020 to 14,700 μS/cm. The high readings found close to Dj. Tamoulga are indicative of the area's high groundwater salinity. A 1:5 diluted soil extract had an electrical conductivity of 200–2000 μS/cm. The western portion of the study area, near the DJ. Tamoulga periphery, had the highest values. On the other hand, the easternmost values were the lowest. A lateral difference in electrical resistivity for the various depths examined was also discovered by the geoelectrical investigation. In general, the resistivity falls from east to west and rises from north to south with distance from DJ. Tamoulga.</div><div>This study demonstrates that deep-seated faults beneath the aquifer close to the Dj. Tamoulga are the source of groundwater salinity.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105858"},"PeriodicalIF":2.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155644","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":"Real-time coastal flood risk assessment using IoT-integrated satellite data and machine learning models for predicting flooding events and informing resilient coastal planning for Durban coastal region, South Africa","authors":"M. Vadivel ,&nbsp;R. Vijaya Saraswathi ,&nbsp;P. Sree Lakshmi ,&nbsp;R Rajaramesh Merugu ,&nbsp;T. Subbulakshmi ,&nbsp;Vivek S.","doi":"10.1016/j.jafrearsci.2025.105856","DOIUrl":"10.1016/j.jafrearsci.2025.105856","url":null,"abstract":"<div><div>Coastal regions around the world are facing growing threats from frequent and intense flooding events driven by climate change, rising sea levels, and unplanned coastal development. To address these challenges, this study aims to develop a real-time coastal flood risk assessment system in Durban, metropolitan area that integrates satellite data, Internet of Things (IoT) sensors, and machine learning techniques. The primary goal is to enhance flood prediction accuracy and support informed, resilient coastal planning and disaster preparedness. The proposed system combines high-resolution satellite imagery with real-time environmental data collected from strategically placed IoT sensors. Key variables include elevation, land use/land cover, slope, rainfall, and tidal fluctuations. A Random Forest machine learning model was used to process and classify these datasets into distinct flood risk categories. The model was trained using historical flood incidents and validated with ground-truth observations, ensuring strong predictive performance and reliability. The flood risk analysis revealed significant spatial variation across the coastal study area. Specifically, 33.15 % (847.35 sq.km) of the region was classified as “Very High” risk, followed by 28.26 % (722.63 sq.km) as “High,” 15.69 % (401.09 sq.km) as “Moderate,” 11.73 % (299.96 sq.km) as “Low,” and 11.14 % (284.97 sq.km) as “Very Low.” These findings emphasize the urgency of focusing risk mitigation strategies in the most vulnerable zones. By providing real-time, data-driven insights, this integrated framework offers a practical and scalable solution for coastal flood risk management. It empowers local authorities, planners, and communities to make proactive decisions that reduce risk and build long-term resilience.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105856"},"PeriodicalIF":2.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220929","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":"Tectonic evolution of the south-eastern Mwanesi Greenstone Belt, Zimbabwe Craton: insights from structural geology and 40Ar/39Ar age constraints","authors":"Brian Mapingere,&nbsp;Jérémie Lehmann,&nbsp;Fanus Viljoen,&nbsp;Georgy Belyanin","doi":"10.1016/j.jafrearsci.2025.105855","DOIUrl":"10.1016/j.jafrearsci.2025.105855","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The south-eastern Mwanesi Greenstone Belt (MGB) comprises variably deformed pillowed and amygdaloidal basalt, variolitic pyroclastic breccia and minor felsic volcanic rocks intercalated with phyllite and iron formation. It is bound to the east and underlain by granitic orthogneiss. New structural analysis combined with mica &lt;sup&gt;40&lt;/sup&gt;Ar/&lt;sup&gt;39&lt;/sup&gt;Ar geochronology allows for the reconstruction of the tectonic history of the area. The data reveal three tectonic events, D&lt;sub&gt;1&lt;/sub&gt;-D&lt;sub&gt;3&lt;/sub&gt;.&lt;/div&gt;&lt;div&gt;D&lt;sub&gt;1&lt;/sub&gt; is constrained at ca. 2680 Ma. In the phyllite of the MGB, it is characterized by recumbent F&lt;sub&gt;1&lt;/sub&gt; folds and an axial planar cleavage S&lt;sub&gt;1&lt;/sub&gt; that developed under greenschist facies metamorphic conditions. In the structurally underlying granite orthogneiss, D&lt;sub&gt;1&lt;/sub&gt; is marked by a shallowly SW-dipping gneissic foliation S&lt;sub&gt;1&lt;/sub&gt; and NW-plunging stretching lineation L&lt;sub&gt;1&lt;/sub&gt;, associated shear sense indicators suggesting top-to-the-NW movement. We interpret D&lt;sub&gt;1&lt;/sub&gt; as recording NW-directed transport of the MGB over the granite orthogneiss. Regionally, D&lt;sub&gt;1&lt;/sub&gt; is likely related to a thrusting event that affected the entire craton.&lt;/div&gt;&lt;div&gt;The D&lt;sub&gt;2&lt;/sub&gt; event, dated at ca. 2575 Ma, led to the development of the N-S-striking Mhou Shear Zone (MSZ)—a one km-thick, steeply west-dipping structure that formed under upper greenschist to lower amphibolite facies metamorphic conditions. The shear zone is mainly localized within the granite orthogneiss and, to a lesser extent, within the MGB. The mylonitic foliation S&lt;sub&gt;2&lt;/sub&gt; carries a subhorizontal stretching lineation L&lt;sub&gt;2&lt;/sub&gt; with associated shear sense indicators suggesting sinistral movement. Outside the shear zone, the intensity of D&lt;sub&gt;2&lt;/sub&gt; deformation progressively decreases eastward within the granite orthogneiss. This decrease is reflected by a change in fold style from isoclinal to open and gentle folds, associated with steep axial planar S&lt;sub&gt;2&lt;/sub&gt; foliations, as well as steeply-dipping N-S-striking reverse faults. This suggests that the MSZ is a wrench-dominated sinistral transpressional shear zone which formed during regional NNW-SSE shortening. The parallel orientation of F&lt;sub&gt;2&lt;/sub&gt; small-scale folds in the granite orthogneiss and the doubly plunging, NNE-trending MGB syncline supports its classification as a D&lt;sub&gt;2&lt;/sub&gt; structure. At the regional scale, the D&lt;sub&gt;2&lt;/sub&gt; event is considered a far-field effect of NNW-SSE thrusting in the Northern Marginal Zone of the Limpopo Belt.&lt;/div&gt;&lt;div&gt;Local and weak Paleoproterozoic tectonic overprint D&lt;sub&gt;3&lt;/sub&gt;, tentatively dated at ca. 2.0 Ga, is characterised by steeply NE-dipping axial planar cleavage S&lt;sub&gt;3&lt;/sub&gt; and F&lt;sub&gt;3&lt;/sub&gt; box folds developed under lower greenschist facies conditions. Our work in the south-eastern MGB demonstrates that orogenic events that affected the Zimbabwe Craton along its margins largely influenced the tectono-thermal ev","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105855"},"PeriodicalIF":2.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119628","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}