Journal of African Earth Sciences最新文献

{"title":"Tomography of the source zone of the February 6, 2023, Kahramanmaraş Earthquake Doublets of Southern Anatolia","authors":"Mohamed K. Salah ,&nbsp;Hamdi Alkan ,&nbsp;Serkan Öztürk ,&nbsp;Recep Güney","doi":"10.1016/j.jafrearsci.2025.105751","DOIUrl":"10.1016/j.jafrearsci.2025.105751","url":null,"abstract":"<div><div>On February 6, 2023, two destructive earthquakes and many posterior aftershocks hit the Kahramanmaraş area in southern Anatolia. The Kahramanmaraş earthquake sequence (KMES) caused extensive damage and economic losses in Türkiye and Syria. In this study, the 3-D crustal seismic velocities surrounding the hypocentral region of the KMES are determined using a large dataset of body wave arrival times obtained from local earthquakes. To better constrain the physical properties and seismogenic behavior of the KMES source region, the Vp/Vs ratio is calculated and correlated with Poisson's ratio using the obtained velocity models. To gain a better understanding of the stress conditions and regional earthquake activity in the study area, the depth variation of the <em>b</em>-value is also examined. The velocity structure is generally heterogeneous with both low and high velocities at upper crustal depths. Along the East Anatolian Fault Zone and its environs, low-velocity anomalies are charted. Also, small <em>b</em>-values (&lt;1.0) are estimated in the region encompassing the KMES, especially at upper crustal depths. The KMES source zone is characterized by low <em>b</em>-value, low to average Vp, low Vs, and average/high Vp/Vs ratios. Hit count rates and the resolution test show that the mapped velocity anomalies are robust down to a depth of 45 km. Therefore, the moderate/high Vp/Vs and small <em>b</em>-values at the upper and middle crustal depths along the EAFZ may give constraints on the next earthquake hazards of the study region. The present findings provide deeper insight into the physical properties and the seismogenic potential of the crustal zones in proximity to the active fault segments of the Anatolian Plateau and the northwestern part of Arabia.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"233 ","pages":"Article 105751"},"PeriodicalIF":2.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100050","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 and geodynamics of clinopyroxenites in faryab metaultramafic sequence (south of Kerman province); Evidences for mantle heterogeneity in southern Iran","authors":"Mojtaba SoltaniNezhad ,&nbsp;Hamid Ahmadipour ,&nbsp;Abbas Moradian ,&nbsp;Kazuo Nakashima","doi":"10.1016/j.jafrearsci.2025.105753","DOIUrl":"10.1016/j.jafrearsci.2025.105753","url":null,"abstract":"<div><div>The Faryab ultramafic complex with Paleozoic age, located in the south east of Kerman province, Iran. Field evidences show that it has emplaced in the Bajgan metamorphic complex after metamorphosing the Bajgan units, and includes harzburgite, lherzolite, dunite, clinopyroxenite, and chromitite. Clinopyroxenite has intruded into the peridotites in the form of dykes and veins and their cumulate texture, indicate that these rocks have crystallized from silicate melts. Mineral chemistry reveals a mantle origin for them (Mg# of Cpx = 91–94) and their whole rock composition is not similar to MORBs and mantle-depleted peridotites (Ni up to 720 ppm and MgO = 32.4 wt%); however, they are depleted in LILE and LREE compared to HREE similar to well-known clinopyroxen asite cumulates. The whole rock chemical composition of Faryab clinopyroxenits (SiO2 = 50.67 and Cr = 6180 ppm) suggests that the parent magmas were probably Low-Ca boninitic melts. These boninites derived from the reaction between primary calcium rich picritic melts and the host peridotites and as they ascend through fractured lithospheric peridotites, leaving behind the Faryab clinopyroxenites. The parallel alternating of clinopyroxenites suggest that the upper mantle in this region likely rose diapirically, causing pressure reduction and partial melting of the upper mantle and resulted in the formation of parallel fractures in the lithosphere. The Faryab clinopyroxenites can be considered as channels through which the supra-subduction zone melts of the Neotethys lithosphere ascended and formed them as relatively high pressure cumulates. The presence of clinopyroxenites and their petrogenetic evolution provide undeniable evidence of upper mantle heterogeneity in south of Iran.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105753"},"PeriodicalIF":2.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563490","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 40Ar/39Ar geochronological data to infer mineralization events in Archean terranes: Comment on Bineli Betsi et al. (2025)","authors":"H.M. Rajesh","doi":"10.1016/j.jafrearsci.2025.105752","DOIUrl":"10.1016/j.jafrearsci.2025.105752","url":null,"abstract":"<div><div>In spite of the wide use of ⁴⁰Ar/³⁹Ar geochronology of potassium-bearing minerals to date mineral deposits, caution needs to be exercised in the interpretation as there is a high chance that the ages have been modified by subsequent events not related to the mineralization. This comment addresses the contentious nature of the c.550 Ma ⁴⁰Ar/³⁹Ar hydrothermal K-feldspar ages from the Mowana copper deposit in NE Botswana, and used by Bineli Betsi et al. (2025) to invoke a much younger mineralization event not compatible with known geologic events within the host Archean terrane. Comparable U-Pb zircon lower intercept ages are widely reported from the different Archean terranes in the region, and shown to be a common result of sub-recent weathering-related Pb-loss. The highly disturbed nature of the ⁴⁰Ar/³⁹Ar spectra presented in Bineli Betsi et al. (2025) is a testament to the modification of the dated K-feldspar and the obtained ages are re-interpreted to indicate alkali redistribution related to weathering in the Archean hinterland. Instead, the Paleoproterozoic ages obtained by earlier studies from Pb-Pb sulphides are suggested to be closer to the timing of mineralization at the Mowana copper deposit.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105752"},"PeriodicalIF":2.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563491","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":"Modelling geologic features and structures in the Middle and Lower Benue Trough of Nigeria from gravity and aeromagnetic data sets","authors":"Ezekiel Yenne,&nbsp;Chris Green,&nbsp;Taija Torvela","doi":"10.1016/j.jafrearsci.2025.105745","DOIUrl":"10.1016/j.jafrearsci.2025.105745","url":null,"abstract":"<div><div>Understanding subsurface structures is key to predicting the evolution of a basin and its resources. The Benue Trough is a mega-structure that has been moderately well studied, although a detailed regional subsurface study of the basin is lacking. Our aim in this study is to highlight and show clearly the subsurface geologic structures/features through 2D and 3D models. We used high-resolution aeromagnetic and gravity datasets to map and investigate geologic features and subsurface structural texture of the trough in 2 and 3 dimensions. We constructed geologic models in 2D from gravity and magnetic datasets and mapped basement faults, depth to basement, Curie, and Moho depths, and interpreted the crustal structure of the basin. Three well-defined basement fault systems were identified: NE-SW, NW-SE, and ENE-WSW. Based on basement fault kinematics through paleo-stress field interpretation, we showed that the basement faults evolved through plate tectonic activities at the earlier stage of the evolution of the trough. We then carefully modelled in 3D critical interfaces (basement surface, Curie isotherm, and Moho), where we estimated their depths and interpreted their morphologies. The average basement depth is 4.3 km and areas of basement lows are interpreted as sub-basins; these are suitable sites for the accumulation of sediments (depocentres) while the basement highs are considered basement uplifts and blocks. The Curie depth (the depth to the bottom of the magnetic layer) is relatively flat across the area while the Moho is uplifted directly under the basin. We observed the crust to be thinned directly under the basin which we attributed to extensional rifting processes. This study exposed the subsurface tectonic architecture of the trough and demonstrated its continental origin due to crustal rifting and extension, accompanied by faulting, Moho shallowing, magma emplacement, and crustal thinning and stretching.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105745"},"PeriodicalIF":2.2,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548697","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":"Diagenesis of the Callovian-Kimmeridgian Antalo Limestone Formation, Blue Nile Basin, Ethiopia: Implications for characterizing hydrocarbon reservoir quality","authors":"Beksa Amente ,&nbsp;Balemwal Atnafu ,&nbsp;Solomon Kassa ,&nbsp;Gilamichael K. Domenico","doi":"10.1016/j.jafrearsci.2025.105750","DOIUrl":"10.1016/j.jafrearsci.2025.105750","url":null,"abstract":"<div><div>Understanding the diagenetic evolution of carbonate formations is essential for evaluating their reservoir potential. This study provides the first integrated analysis of the diagenetic process affecting the reservoir quality of the Callovian-Kimmeridgian Antalo Limestone Formation in the Blue Nile Basin. Extensive field investigations, including detailed section logging and rock sample collection, were conducted across the Dejen-Gohatsion traverse, Jemma, and Mugher areas. From the collected rock samples, 115 representative samples were selected for petrographic analysis to assess the key diagenetic processes controlling porosity and reservoir quality of the carbonate deposits. The analysis reveals that calcite cementation and dissolution are the most prominent porosity-reducing and enhancing diagenetic processes, respectively. Other processes such as compaction, dolomitization, silicification, bioturbation, micritization, and fracturing diagenetic processes have significantly influenced primary and secondary porosity development, and reservoir quality of the Antalo Limestone Formation. This study provides insight into the Antalo Limestone reservoir quality in the Blue Nile Basin. Moreover, it offers important baseline data to guide future exploration and advanced investigations aimed at re-evaluating the formation as a significant reservoir. It also enhances the current understanding of reservoir heterogeneity in Ethiopian Jurassic carbonates and contributes valuable insights for regional hydrocarbon exploration.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"230 ","pages":"Article 105750"},"PeriodicalIF":2.2,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517308","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":"Multi-disciplinary approach to evaluate hydrocarbon potential in the Bornu Basin, Northeastern Nigeria","authors":"Chekwube Nnamdi Didi ,&nbsp;Olawale Olakunle Osinowo ,&nbsp;Okey Eliseus Akpunonu ,&nbsp;Solomon Ekene Okeke","doi":"10.1016/j.jafrearsci.2025.105742","DOIUrl":"10.1016/j.jafrearsci.2025.105742","url":null,"abstract":"<div><div>The Bornu Basin, a sub-basin of the Chad Basin in northeastern Nigeria, has experienced extensive petroleum exploration activities, with 23 wells drilled; however, only two encountered sub-commercial gas volumes. This study integrates well log data, sequence and seismic stratigraphy, structural interpretation, and fault seal analysis to better understand reservoir extent, depositional environments, and hydrocarbon trapping mechanisms. Well log analysis reveals a stratigraphic sequence gently dipping from southwest to northeast. The lowermost Bima Formation (Albian), composed mostly of sandstone, reflects a fluvial to continental setting. The Gongila Formation consists of interbedded lithologies, thinning southwestward. The Fika Shale, marked by high gamma ray readings, serves as a thick, continuous seal. The Gombe Formation, with alternating sands and shales, indicates fluvial to shallow marine conditions. The sandy Kerri-Kerri Formation suggests a continental environment, while the Chad Formation comprises clays and shales with minor sandstones. Sequence stratigraphic analysis identified three third-order sequences. Reservoir evaluation in Bulte-1 and Kasade-1 wells identified three potential reservoir zones (Cha-Res-1, -2, -3) in the Kerri-Kerri, Gombe, and Gongila Formations; respectively. The Kerri-Kerri and Gombe Formations show better reservoir quality with good porosity (0.13–0.18) and net to gross (0.93–0.98); respectively, while the Gongila Formation is poorer due to higher shale content (0.150–0.157) and high-water saturation (0.99–1.00). Seismic data revealed complex faulting patterns like normal, listric, and reverse especially in deeper zones, along with possible igneous intrusions. Two anticlinal leads were identified. Fault seal analysis suggests moderate sealing capacity with a Shale Gouge Ratio of 0.22–0.35. Rose diagram, Fisher mean vector statistics and Bingham axial distribution analysis suggest that the faults are trending in Northeast-southwest direction.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"230 ","pages":"Article 105742"},"PeriodicalIF":2.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518189","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":"Hydrogeology and structure of the liassic causse aquifer in El Menzel-Ribat El kheir (Middle Atlas, Morocco): an integrated approach combining a structural analysis and remote sensing","authors":"Youssef Drissi ,&nbsp;Mohammed Laiche ,&nbsp;Saïd Hinaje ,&nbsp;Anas Laksir ,&nbsp;Mohamed El Fartati ,&nbsp;Driss Yaagoub","doi":"10.1016/j.jafrearsci.2025.105744","DOIUrl":"10.1016/j.jafrearsci.2025.105744","url":null,"abstract":"<div><div>The unconfined aquifer hosted within the Lower to Middle Liassic carbonate formations of the Middle Atlas Causse (Morocco) serves as a critical water resource for both domestic and agricultural use in the El Menzel–Ribat El Kheir region in the Sefrou Province. This study investigates the structural controls on groundwater dynamics and aquifer geometry, with the aim of improving water resource management in a region increasingly affected by water scarcity.</div><div>A multi-source geostructural analysis was conducted by integrating remote sensing data and field investigations. Lineament mapping was performed using the first principal component (PCA-1) of Landsat 9 imagery and hillshade models derived from ASTER-DEM. These were complemented by detailed geological fieldwork and structural measurements, including analysis of striated faults, joints, and tension cracks.</div><div>The study identified both inherited and neoformed fault systems, with dominant orientations of N30° to N50°, N75° to N105°, N120° to N140°, and N160° to N10°. Rose diagram comparisons between remote sensing data and field observations confirmed a strong correlation between extracted lineaments and major fault trends. These faults, generated and reactivated through polyphased tectonic activity from the syn-to post-Upper Miocene, have played a fundamental role in shaping aquifer compartments.</div><div>Overlaying piezometric data from wells and boreholes onto fracture maps revealed a southeast-to-northwest groundwater flow direction, aligned with NW–SE-trending faults and generally perpendicular to Quaternary N30° faults. These structural features have contributed to the tectonic compartmentalization of the area into synthetic tilted blocks, promoting NW-directed collapse. This structural configuration facilitates the emergence of major springs, Aïn Mehraz, Aïn El Kebir, Aïn Tazroute, and Aïn Tamezoughte, along fault zones and tectonic intersections.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"230 ","pages":"Article 105744"},"PeriodicalIF":2.2,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517310","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":"Hysteresis and thermomagnetic characteristics of soils and rocks in eastern Botswana","authors":"Moikwathai Moidaki,&nbsp;RubeniT. Ranganai,&nbsp;James G. King","doi":"10.1016/j.jafrearsci.2025.105747","DOIUrl":"10.1016/j.jafrearsci.2025.105747","url":null,"abstract":"<div><div>Rock magnetic properties are integral to various applications, including palaeomagnetism, plate tectonics, geological interpretation, geoexploration, mining, forensics, and engineering. This study builds upon previous research on the magnetic susceptibilities of soils in eastern Botswana, focusing on key magnetic parameters such as the Curie temperature (Tc), determined in a nitrogen atmosphere, and hysteresis variables (coercive force: Hc, coercive remanence: Hcr, saturation remanence magnetisation: Mrs, saturation magnetisation: Ms). Thermomagnetic curves, measured from room temperature up to 700 °C, facilitated the classification of magnetic mineralogy and granulometry.</div></div><div><h3>Results</h3><div>reveal the presence of magnetic minerals such as hematite, magnetite, and pyrrhotite, with Curie temperatures approximately at 600 °C, 580 °C, and 200 °C, respectively. Hysteresis loops further support the dominance of magnetite-like phases in the soil samples. Both hysteresis and thermomagnetic data suggest magnetite as the primary contributor to the magnetic properties. Notably, thermomagnetic analyses of soils along the Ramatlabama to Ramokgwebana transect—crossing the Kaapvaal Craton, Limpopo Belt, and Zimbabwe Craton—offer potential for delineating the boundaries of these cratonic regions and associated orogenic belts. Thus, expanding research coverage across different terrains and geological settings would further enhance our understanding of crustal processes and magnetic mineral distributions invaluable for geological modelling and exploration for raw material deposits.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105747"},"PeriodicalIF":2.2,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144587738","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":"Biostratigraphic and sequence stratigraphic study of the Late Cretaceous-Paleogene succession in the Anambra Basin, southeastern Nigeria: Insights from the Amama-1 and Bara-1 wells","authors":"Joy Obiageli Njoku ,&nbsp;Timothy Chibuike Anyanwu ,&nbsp;Diugo Okereke Ikoro ,&nbsp;Geoffrey Chijioke Soronnadi-Ononiwu ,&nbsp;Jones Edward Acra ,&nbsp;Emeka Austin Okoli ,&nbsp;Chidiebere Charles Agoha","doi":"10.1016/j.jafrearsci.2025.105741","DOIUrl":"10.1016/j.jafrearsci.2025.105741","url":null,"abstract":"<div><div>This study presents an integrated biostratigraphic and sequence stratigraphic analysis of the Late Cretaceous–Paleogene succession in the Anambra Basin, southeastern Nigeria, based on data from the Amama-1 and Bara-1 exploration wells. The aim is to refine the chronostratigraphic framework and reconstruct the depositional history of the basin. Lithostratigraphic, palynological, foraminiferal, and wireline log datasets were combined to delineate major stratigraphic units, identify maximum flooding surfaces (MFS), sequence boundaries (SB), and establish systems tracts. Key formations encountered include the Nkporo, Mamu, Ajali, and Nsukka Formations, revealing varied depositional settings ranging from marginal marine to fluvial environments. Biostratigraphic zonations identified include the <em>Globotruncanella havanensis</em>, <em>Bolivina afra/B. explicata</em>, and <em>Morozovella velascoensis</em> foraminiferal zones, and palynological zones such as <em>Ctenolophonidites costatus</em> and <em>Retidiporites miniporatus</em>. Chronostratigraphic calibration and paleoenvironmental interpretations correlate closely with regional and global stratigraphic events. The findings affirm the Anambra Basin's significance in petroleum system evaluation and underscore the utility of integrated stratigraphic methods in subsurface reservoir characterization.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"230 ","pages":"Article 105741"},"PeriodicalIF":2.2,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144535700","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":"Frasnian conodont abundance and environmental control in northwestern Algerian Sahara","authors":"Abdessamed Mahboubi ,&nbsp;Salamet Mahboubi ,&nbsp;Zhor Sarah Aboussalam ,&nbsp;Hocine Djouder ,&nbsp;Michał Zatoń","doi":"10.1016/j.jafrearsci.2025.105740","DOIUrl":"10.1016/j.jafrearsci.2025.105740","url":null,"abstract":"<div><div>The conodont abundance and diversity of the Frasnian (Upper Devonian) is analyzed in two well-exposed geological sections, so-called Ben Zireg and South Marhouma of the northwestern Algerian Sahara. The results presented herein show a significant conodont abundance in the Ben Zireg section with 117 elements/kg, which is higher than that observed in the South Marhouma section with only 14 elements/kg. The magnetic susceptibility measurements presented herein may suggest the impact of the terrigenous input on conodont abundance. Indeed, the strata belonging to the middle Frasnian substage in both sections expose higher MS values matching with lower conodont diversity. However, the decrease of the MS signal is correlated with a constant increase in conodont abundance This new quantitative MS-conodont, revealed by an inverse correlation between MS and conodont abundance, suggesting that MS could potentially serve as a proxy for paleoecological interpretations.</div><div>The comparison between Ben Zireg and southern Marhouma illustrates the key role of paleogeography in shaping conodont abundance along the stable Gondwana margin. Proximal areas such as Marhouma, located closer to the paleocontinents, were more exposed to elevated detrital input, which likely suppressed conodont proliferation and led to reduced abundance. In contrast, more distal settings like Ben Zireg were exposed to lower terrigenous influx, resulting more optimal ecological conditions that supported higher conodont abundance and diversity.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"230 ","pages":"Article 105740"},"PeriodicalIF":2.2,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522693","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}