Journal of African Earth Sciences最新文献

{"title":"Site classification and soil liquefaction evaluation based on shear wave velocity via HoliSurface approach","authors":"Albert Kafui Klu ,&nbsp;Michael Affam ,&nbsp;Anthony Ewusi ,&nbsp;Yao Yevenyo Ziggah ,&nbsp;Emmanuel Kofi Boateng","doi":"10.1016/j.jafrearsci.2025.105574","DOIUrl":"10.1016/j.jafrearsci.2025.105574","url":null,"abstract":"<div><div>This study employs the HoliSurface technique, a geophysical method, to classify sites and evaluate liquefaction susceptibility in the southwestern Greater Accra Region of Ghana. Shear wave velocity (Vs) profiles to a depth of 13 m were acquired from 26 surveyed sites. A reliable extrapolation method was then used to estimate the Vs₃₀ (Vs₃₀₍₁₃₎) of each site, allowing classification based on the Eurocode 8 system. Most sites (20) were classified as Site Class C (Vs₃₀: 180–360 m/s), indicating moderately dense soils with improved geomechanical properties at depth. Five sites exhibited high stiffness and resistance to liquefaction (Site Class B). The site at Tetegu East (Vs₃₀: 110 m/s, FoS: 0.525) was, however, found to be extremely weak (Site Class D), hence prone to seismic failure. Airport City (Vs₃₀: 190 m/s, FoS: 0.647), despite a Site Class C classification, exhibited a low FoS value, indicating liquefaction susceptibility. A key limitation of this study was the inability to acquire Vs data to a depth of 30 m due to spatial constraints at most sites, necessitating the use of extrapolated Vs₃₀ values, which may introduce uncertainties. Additionally, joint inversion of group velocity dispersion with HVSR or RMP curves, which could enhance reliability, was not employed due to the preliminary nature of this study. Despite these limitations, the findings align with established standards and provide critical insights for urban planning, highlighting the need for interventions in high-risk zones to mitigate potential disasters.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105574"},"PeriodicalIF":2.2,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403279","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":"Petrogenesis of rare-metal pegmatites in northeastern part of Nasarawa, northcentral basement complex of Nigeria","authors":"Anthony Chukwu ,&nbsp;Smart Chika Obiora ,&nbsp;Theophilus C. Davies","doi":"10.1016/j.jafrearsci.2025.105565","DOIUrl":"10.1016/j.jafrearsci.2025.105565","url":null,"abstract":"<div><div>The pegmatites in Nasarawa region of northcentral Nigeria are within the Pan-African remobilized belt of Basement rocks of Nigeria, along Eggon-Wamba axis. Pan African orogenic events gave rise to reworked, crustal thickening and decompression which resulted to syn-to post-collision rocks (granitic rocks and pegmatites). The rare-metal pegmatites are classified as albite-muscovite pegmatites and biotite-microcline pegmatites. The area is predominantly underlain by migmatitic banded gneiss and localized biotite-muscovite gneiss which host most of the rare-metal pegmatites. The pegmatites mostly occur in NNW-SSE direction with few NE-SW orientations. The rare metal pegmatites contain albite, muscovite, quartz and microcline, while garnet, black tourmaline (schorl), apatite, beryl, ilmenites and minor Sn-Nb-Ta oxides occur as accessory. The biotite-microcline pegmatites possess less accessory minerals. The host rocks are made up of quartz, albite-andesine, microcline, biotite, muscovite and hornblende. Minor constituents include orthopyroxene, cordierite, sillimanite, garnet and chlorite. The rocks in the area (pegmatites and migmatitic rocks) show extreme peraluminous and exhibiting similar geochemical signatures suggesting genetic relationship. The albite-muscovite pegmatites are enriched in Rb, B, Li, Cs, Sn, Nb &gt; Ta, W, Be and Ga over the biotite-microcline pegmatites and exhibit low values of K/Rb, Mg/Li and Zr/Hf across the zones. They have higher potential for cassiterite and columbite over tantalite. Modal equilibrium batch melting model supports anatexis of the migmatitic-gneiss complex at depth rather than the Pan-African granites origin as earlier believed.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105565"},"PeriodicalIF":2.2,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403278","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":"Structural and facies modeling of the Aptian Dahab Formation, Matruh Basin, northern Western Desert, Egypt","authors":"Marwa Yousef ,&nbsp;Luis Vergara ,&nbsp;Adel R. Moustafa ,&nbsp;William Bosworth","doi":"10.1016/j.jafrearsci.2025.105573","DOIUrl":"10.1016/j.jafrearsci.2025.105573","url":null,"abstract":"<div><div>This paper presents a comprehensive study of the structural geometry and tectonic evolution of the Aptian Dahab Formation in the Matruh Basin, Egypt, using high-quality 3D seismic and well data. It also details the methodologies used to develop precise 3D structural and facies models for the Dahab Formation in the study area, which elucidate the stratigraphic succession, depositional environments and facies, tectonic and eustatic influences on deposition, and the spatial distribution of the Dahab Formation.</div><div>Detailed well log correlations indicate the presence of normal faults, affecting the preservation of the upper part of the Dahab Formation in the boreholes. The study employs a 3D structural modeling workflow, integrating seismic and well data, structural cross-sections, and maps. Velocity modeling and depth conversion highlight the complex structural setting resulting from the impact of Late Cretaceous faulting and folding on the Aptian Dahab Formation.</div><div>Further, a 3D facies model was constructed, that incorporated upscaled well logs and variogram analysis. The results indicate that the lithological composition of the Dahab Formation in the study area is 38.4% shale, 28.96% siltstone, 15.35% sandstone, 12.36% limestone, and 4.92% dolostone. Hence, the facies model shows the dominance of shale facies, which increase towards the south, while siltstone and sandstone facies become more prevalent towards the north, likely sourced from that direction. Two cross sections were constructed that illustrate the lateral and vertical facies variations within the Dahab Formation, which thickens as it extends northwestward. Consequently, the facies distribution model of the Aptian Dahab Formation could serve as a global analogue for potential siliciclastic reservoirs deposited in a shallow water environment.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105573"},"PeriodicalIF":2.2,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394491","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":"Gravity-based structural and tectonic characterization of the Shendi-Atbara Basin, Central Sudan","authors":"Ali A. Mohieldain ,&nbsp;Mihály Dobróka ,&nbsp;Musaab A.A. Mohammed ,&nbsp;Norbert P. Szabó","doi":"10.1016/j.jafrearsci.2025.105571","DOIUrl":"10.1016/j.jafrearsci.2025.105571","url":null,"abstract":"<div><div>This study employs gravity data analysis techniques to investigate the subsurface structural framework and lithological variations of the Shendi-Atbara Basin in Sudan. This basin is influenced by both the Mesozoic rifting associated with the West and Central African Rift System (WCARS) and the Neoproterozoic tectonics of the Nubian Shield. High-resolution satellite gravity data were analyzed using potential field methods including anomaly separation, edge detection, and 2D and 3D modeling to delineate primary structural features and density interfaces. Various edge detection techniques were applied to identify lineament structures, and the results were integrated to construct a comprehensive structural map of the region. This map was subsequently analyzed to interpret the tectonic evolution and subsurface geology. Structural analysis revealed three dominant fracture sets: NW-SE extensional fractures, NE-SW release fractures, and N-S shear fractures. Gravity modeling indicated that the thickness of the sedimentary sequences in the Shendi-Atbara Basin reaches up to 4800 m. A notable high-density anomaly southeast of Shendi is interpreted as an intermediate to mafic igneous intrusion, corroborated by surrounding structural patterns identified through edge detection and modeling. These findings provide valuable insights into the basin's tectonic evolution. The identified fractures serve as important guides for groundwater and mineral resource exploration, particularly given the presence of high-density sources and iron-rich sedimentary formations in the region.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105571"},"PeriodicalIF":2.2,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reservoir characterization and facies modeling of the gas-bearing Kafr El Sheikh and Abu Madi reservoirs in the Disouq Field, Nile delta, Egypt: An integrated petrophysical, pressure, and seismic study","authors":"Mennat Allah Nafady ,&nbsp;Munir Elmahdy ,&nbsp;Ahmed A. Radwan ,&nbsp;Bassem S. Nabawy ,&nbsp;Ahmed Abdelhady ,&nbsp;Abdalla Mousa El-Ayyat ,&nbsp;Ezzat A. Ahmed","doi":"10.1016/j.jafrearsci.2025.105566","DOIUrl":"10.1016/j.jafrearsci.2025.105566","url":null,"abstract":"<div><div>Kafr El Sheikh (KES) and Abu Madi formations are among the potential gas-producing reservoirs in the Nile Delta, promoting numerous efforts to characterize them. Based on a full set of conventional well log data from four wells in the Disouq Field in the northwestern Desert, the petrophysical properties and hydrocarbon potentiality of these two formations were figured out. When litho-saturation, neutron-density, and M-N plots are integrated together, they show that the two studied reservoirs are mostly made up of shale with some sand lenses and lobes that could be potential reservoirs. We further subdivide the KES Formation into KES IIIA, KES IIIB, KES IIIC, and KES IIID based on the petrophysical data. The petrophysical parameters of both the Abu Madi Formation (7.77 m &lt; net-pay &lt;13.72 m, 20.8% &lt; ∅e &lt; 25.8%, 34.4% &lt; Sw &lt; 51.8%, and 20.3% &lt; Vsh &lt;22.6%) and the KES Formation (1.98 m &lt; net-pay &lt;10.0 m, 23.1% &lt; ∅e &lt; 25.3%, 29.5% &lt; Sw &lt; 42.4%, and 29.0% &lt; Vsh &lt;32.0%) indicate a high potentiality for these two reservoirs. The seismic data revealed the existence of an E-W trending 4-way dip closure and a major N-S normal fault that intersects the field, forming an anticline in its upper block. The pressure data from the repeat formation tester (RFT) helped figure out the free water level (FWL) between the gas and water aquifer at depths of 7296 ft and 7850 ft for the DSQ 1–3 and DSQ 1–5 wells. In the DSQ-2X well, the water is found at a shallower depth interval (upper compartment at 1943–2170 m depth interval) than in two deeper gas-bearing reservoirs (middle and lower compartments at 2170–2230 m and 2230–2270 m depth intervals), which means that there are three separate compartments.</div><div>The integration between the well log and seismic data enabled more detailed delineation for the complex structural setting of the field and detailed characterization for its reservoir and petrophysical properties. This study is applicable to the similar 4-way dip closure, which is dominant in the Nile Delta and other similar prograding river-dominated deltas. Analogous sequences in deltaic and nearshore areas in Africa and worldwide can utilize the applied workflow.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105566"},"PeriodicalIF":2.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419528","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":"Petrological constraints of the Ediacaran magmatic intrusions, Homrit Mukpid area, southeastern Desert, Egypt: Bulk rock geochemistry and mineralogy","authors":"El Saeed R. Lasheen ,&nbsp;Rainer Abart ,&nbsp;Mohamed S. Ahmed ,&nbsp;Khaled M. Abdelfadil ,&nbsp;Esam S. Farahat ,&nbsp;Mabrouk Sami","doi":"10.1016/j.jafrearsci.2025.105567","DOIUrl":"10.1016/j.jafrearsci.2025.105567","url":null,"abstract":"<div><div>The study provides a comprehensive investigation into the evolution and petrogenesis of the Homrit Mukpid (HM) granitic suites, emphasizing their petrological characteristics. The HM granitic rocks comprise two main suites: the older granodioritic suite (GHM) and the younger alkali-feldspar granite suite (AHM). The GHM exhibits notable enrichment in TiO₂, MgO, CaO, Fe₂O₃, Sr, Ba, Cr, V, and Sc, and lower concentrations of Ta, Th, Rb, Y, Nb, Sn, Ga, U, Pb, Zn, and ∑REEs compared to the AHM. Geochemically, GHM is distinguished by pronounced negative P, Ti, and Nb anomalies, as well as a decrease in HREEs (avg. ≈ 11 ppm) relative to LREEs (avg. ≈ 83 ppm) and a moderately negative Eu anomaly (avg. ≈ Eu/Eu∗ = 0.78), characteristic of substantially fractionated, subduction-related I-type magmatic sources. In contrast, the AHM displays high SiO₂ (avg. ≈ 75 wt%), total alkalis (avg. ≈ 9 wt%), and higher FeO/MgO, and Rb contents. Their REEs pattern shows a strong negative Eu anomaly (av. Eu/Eu∗ ≈0.08) and HREEs enrichment, indicative of post-collisional A₂-type granites. Importantly, there is no evidence of M-type tetrad effect, as determined using both the lambda and Irber methods. The evoultion of the HM, as a part of the Arabian Nubian Shield, is marked by distinct stages of collision and post-collision, as inferred from the mineralogical and geochemical data of granitic rocks. The GHM is formed from the subducted slab dehydrating, which facilitated the melting of the upper mantle, providing underplating of high K-mafic melts. The GHM formation is attributed to the dehydration of a subducted slab, which triggered upper mantle melting and the generation of high-K mafic melts. This melt subsequently underwent melting and fractionation at elevated temperatures (avg. ≈ 809 °C, using zircon saturation temperature). Conversely, the AHM formed through slab delamination, inducing asthenospheric upwelling and the melting of tonalitic/clay-rich metapelite rocks, followed by extreme fractional crystallization processes during a post-collisional extension episode at low temperatures (avg. ≈ 784 °C) and shallow depths.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"225 ","pages":"Article 105567"},"PeriodicalIF":2.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419529","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":"Petrogenesis of migmatites from Liman Katagum area (Bauchi) North-East Nigeria: Constraints from U-Pb and Lu-Hf isotopic data","authors":"Maimunatu Halilu ,&nbsp;Ahmed Isah Haruna ,&nbsp;Faisal Abdullahi ,&nbsp;Mohamed S. Ahmed ,&nbsp;Vandi Dlama Kamaunji ,&nbsp;Musa Bala Girei ,&nbsp;Ioan V. Sanislav ,&nbsp;El Saeed R. Lasheen ,&nbsp;Mabrouk Sami","doi":"10.1016/j.jafrearsci.2025.105562","DOIUrl":"10.1016/j.jafrearsci.2025.105562","url":null,"abstract":"<div><div>This study investigates the petrogenesis and tectonic evolution of migmatites from the Liman Katagum area in northeast Nigeria. In-situ Lu-Hf isotopic analyses of zircon reveal a complex source history, with εHf(t) values ranging from −13.43 to +8.95 at different ages (482 ± 120 Ma, 582.2 ± 9.0 Ma, and 498 ± 43 Ma). These values suggest contributions from both ancient reworked and juvenile crustal materials, spanning the Chondrite Uniform Reservoir (CHUR) and various crustal domains, indicating significant crustal recycling and juvenile additions. High zircon U/Yb ratios, along with elevated Y and Hf, reflect a strong continental arc affinity, supporting a crustal origin for the migmatites. Geochemical and morphological evidence, including enriched heavy rare earth elements (HREEs) and variable Th/U ratios, indicate both magmatic and metamorphic origins for the zircons, consistent with early Silurian arc magmatism. U-Pb zircon ages of 582.2 ± 9.0 Ma, 498 ± 43 Ma, and 482 ± 120 Ma correspond to distinct tectonic events, including the Pan-African orogeny. The earliest stage, at 582.2 Ma, shows significant juvenile crustal input during continental arc magmatism in the Neoproterozoic. By 498 Ma, tectonic reactivation led to partial melting and zircon crystallization, while the final stage at 482 Ma is linked to high-pressure metamorphism and crustal thickening during the collision of the West African Craton and the Tuareg Shield. Two distinct zircon age groups (582.2 ± 9.0 Ma and 498 ± 43 Ma) reflect the reworking of the Paleoproterozoic and Mesoproterozoic crust, with substantial juvenile input. This tectonic evolution, initiated around 482 Ma, involved crustal thickening, metamorphism, and partial melting, forming migmatites. Continued tectonic activity around 582 Ma caused shear zone development and crustal reworking, while reactivation at 498 Ma led to the crystallization of new zircons and the formation of migmatites. This study, similar to migmatite studies across Africa, elucidates the dual-source history of the Liman Katagum migmatites, with contributions from both reworked and juvenile crustal materials during the late Neoproterozoic and Early Paleozoic, highlighting episodes of partial melting and magma intrusion associated with the breakup of Rodinia and the assembly of Gondwana.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"224 ","pages":"Article 105562"},"PeriodicalIF":2.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349399","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":"Distribution of recent ostracods and benthic foraminifera from Farwa Lagoon (NW Libya)","authors":"Sherif M. El Baz ,&nbsp;Abdalla Shahin ,&nbsp;Ahmed Al Furjany ,&nbsp;Hatem Aboelkhair ,&nbsp;Asmaa Awad","doi":"10.1016/j.jafrearsci.2025.105564","DOIUrl":"10.1016/j.jafrearsci.2025.105564","url":null,"abstract":"<div><div>This paper presents the first detailed study of recent ostracods and foraminiferal assemblages found in the bottom sediments of the Farwa Lagoon on the northwestern coast of Libya. The studied assemblages consist of 25 ostracod species belonging to 17 genera, and 49 foraminiferal species, belonging to 21 genera. The abundance and diversity of these two groups of microorganisms vary among sites, providing the possibility of using ostracods and benthic foraminifera as bio-indicators in the Farwa Lagoon. Their distributions are influenced by many limnological conditions, including salinity, sediment types, the presence of seagrass cover, and hydrodynamic forces, as well as by pollution sources. <em>Xestoleberis communis</em> Müller, a common marine species, is the source of &gt;40% of the ostracod valves counted and is found at 12 of the 15 sites. Six other species account for ∼30% of the valves, including <em>Cyprideis torosa</em> (Jones), <em>Aurila convexa</em> (Baird)<em>, A. woodwardii</em> (Brady)<em>, Pontocythere turbida</em> (Müller), <em>Celtia emaciata</em> (Brady)<em>,</em> and <em>Loxoconcha rhomboidea</em> (Fischer). Foraminiferal tests are more abundant as well as more species rich, with tests of <em>Ammonia parkinsoniana</em> (d'Orbigny) making up 13% of the assemblage and only four other species accounting for at least 5%, notably <em>Elphidium crispum</em> (Linnaeus), <em>Peneroplis planatus</em> (Fichtel and Moll), <em>Ammonia beccarii</em> (Linnaeus), <em>Quinqueloculina seminulum</em> (Linnaeus)<em>.</em> The foraminiferal species can be categorized as free-living (e.g., <em>Quinqueloculina</em>)<em>,</em> and epiphytic taxa (e.g., <em>Peneroplis, Ammonia, Elphidium</em>). The identified assemblages are widely distributed in the shallow marine environments along the Mediterranean coasts, such as Morocco, Tunisia, Egypt, Turkey, Spain and Italy.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"224 ","pages":"Article 105564"},"PeriodicalIF":2.2,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143347925","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":"Geological/petrophysical characterisation and permeability mapping using ANN in the Algerian tight gas reservoir, Illizi Basin","authors":"Chehili Djamel ,&nbsp;Bacetti Abdelmoumen ,&nbsp;Bendali Mehdi ,&nbsp;Rahmani Badr Eddine ,&nbsp;Sadek Kaddour ,&nbsp;Bennour Mohamed amin","doi":"10.1016/j.jafrearsci.2025.105561","DOIUrl":"10.1016/j.jafrearsci.2025.105561","url":null,"abstract":"<div><div>The study of reservoir permeability and porosity is paramount for effective reservoir management and formulation of a production strategy. The Illizi Basin is a Palaeozoic–Mesozoic intraplate depression that preserves over 7000 m of sedimentary rock record and contains world-class petroleum systems with an estimated ultimate recovery (EUR) of over 39 billion barrels of oil equivalent (BBOE) in hydrocarbon reserves. However, predicting and characterising high-permeability (K) zones in such tight gas reservoirs remains challenging due to their complex geological settings and limited well data. This research addresses the critical dilemma of accurately identifying and classifying high-permeability zones in the Illizi Basin. We propose a novel approach that combines conventional geological, sedimentological, and petrophysical analyses with advanced artificial neural networks (ANNs) optimised using deep learning techniques. The study focuses on the north-western part of the basin, where distinguishing permeability facies using conventional methods is particularly difficult. The novelty of this work lies in the application of a highly efficient ANN model for detecting and classifying high-permeability zones, significantly improving the understanding of permeability distribution within the reservoir. The ANN approach demonstrated exceptional performance, enabling the accurate classification of permeability facies and the detection of high-permeability zones in all wells across the study area. This innovative integration of deep learning with traditional reservoir characterisation techniques provides a more reliable framework for reservoir management in tight gas formations like in the Illizi Basin.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"224 ","pages":"Article 105561"},"PeriodicalIF":2.2,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372835","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":"Tracing 8,000 years of climate change and human influence in the Middle Atlas, Morocco: A palynological study from Lake Iffer","authors":"Mariam Bourchachen ,&nbsp;Bouchra Lemdeghri Alaoui ,&nbsp;Khalil Azennoud ,&nbsp;Abdennasser Baali","doi":"10.1016/j.jafrearsci.2025.105563","DOIUrl":"10.1016/j.jafrearsci.2025.105563","url":null,"abstract":"<div><div>This study reconstructs Middle to Late Holocene environmental changes and human impacts in the Moroccan Middle Atlas, using palynological data from Lake (Dayet) Iffer. The sedimentary sequence spans the last 8000 calendar years <em>before present</em> (cal yr BP), revealing a dynamic interaction between natural and anthropogenic factors shaping the vegetation in the region. Tree taxa, primarily <em>Pinus</em>, <em>Pistacia</em>, and <em>Quercus</em> (ilex-type and faginea-type), dominated the landscape until ca. 5500 cal yr BP. The onset of the expansion of drought-tolerant species and herbaceous plants aligns with increasing human activities, as inferred from a significant rise in <em>Olea europaea</em> pollen and forest degradation after ca. 3500 cal yr BP. This period recorded the retreat of pine forests and the emergence of <em>Cistus</em> species, reflecting intensified anthropogenic pressures and changing land use. The study also identifies a major shift around 2500 cal yr BP, characterized by extensive deforestation, soil erosion, and the decline of <em>Cedrus atlantica</em>, likely due to combined effects of aridification and sustained human exploitation.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"224 ","pages":"Article 105563"},"PeriodicalIF":2.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143347924","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}