Journal of African Earth Sciences最新文献

{"title":"Geotechnical behaviour of organic soil modified with natural pumice and zeolite: Implications for sustainable use of volcanic raw materials for soil stabilization","authors":"Suleyman Demir","doi":"10.1016/j.jafrearsci.2026.106037","DOIUrl":"10.1016/j.jafrearsci.2026.106037","url":null,"abstract":"<div><div>This study presents the effect of zeolite (NZ) and pumice powder (PP) on some engineering properties of an organic soil. Organic soil treated with NZ and PP separately, with 10, 20, 30, and 40 % additive ratios, was investigated with compaction, fall cone, and unconfined compression (UC) tests, and a model. The axial stress values from UC tests were fitted using a second-order polynomial response surface model (RSM). The sensitivity of the model was investigated with partial derivative plots. The findings showed that the liquid limit and optimum water content (w_opt) values of organic soil decreased with both NZ and PP additions. 40 % PP and NZ improved the maximum dry density (γ_dmax) value of organic soil by 16 % and 7.2 %, respectively. Unconfined compressive strength (q_u) value of organic soil increased by 18 %, with 40 % PP additions. 10 % NZ and PP additions increased the energy absorption capacity value of clean organic soil by 36 % and 13 %, respectively. At a given content, PP-treated organic soil exhibited a greater q_u than NZ-treated organic soil. SEM photos of treated specimens showed some interparticle contacts between additives, which contributed to the strength improvement of the mixtures. The RSM revealed the coefficients of determination (R²) values of 0.93 and 0.97 for PP and NZ-treated mixtures, respectively. Sensitivity analysis showed that the stress is governed by strain at small deformation levels, while the additive content decreased the strain softening at large strain levels. Consequently, this study presents important insights into the macro and micro-mechanics of PP and NZ-stabilized organic soils.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106037"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090428","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":"Airborne gamma-ray spectrometry survey over the Bou Azzer-El Graara Inlier (Central Anti-Atlas, Morocco): implications for mineral exploration","authors":"Fouzia Anzar ,&nbsp;Saïd Ilmen ,&nbsp;Mohammed Jaffal ,&nbsp;Abderrahmane Soulaimani","doi":"10.1016/j.jafrearsci.2026.106038","DOIUrl":"10.1016/j.jafrearsci.2026.106038","url":null,"abstract":"<div><div>This study provides a comprehensive analysis of airborne gamma-ray spectrometry (GRS) data from the Bou Azzer–El Graara inlier in the central Anti-Atlas Mountains of Morocco. This region is geologically complex, renowned for its Pan-African suture zone and abundant cobalt, copper, and uranium mineralization. High-resolution GRS data, acquired during helicopter surveys in 1998 and 1999, were processed to map the distribution and ratios of naturally occurring radioactive elements (uranium, thorium, and potassium) and to delineate anomalous areas associated with hydrothermal alteration and mineralization. The integration of geological and remote sensing data revealed significant spatial correlations. Cobalt mineralization exhibited a high eU/K ratio, indicating the presence of uranium-rich hydrothermal fluids during cobalt deposit formation. The occurrence of copper mineralization correlates with typical eTh/K anomalies in felsic volcanic systems. Radiometric dating data also identified uranium-rich mineralization zones, primarily located within the Ediacaran volcanic rocks. Tectonic analysis revealed major fault activity controlling fluid flow and alteration patterns, thus aiding in orebody localization. Ternary K-eU-eTh maps further distinguished lithological units and alteration halos. These results highlight the value of gamma-ray spectrometry (GRS) in rapid and efficient mineral exploration, particularly in the exploration of cobalt deposits associated with uranium anomalies. The study recommends further ground-based radiometric surveys in the Bou Azzer mining area to optimize target locations and highlights the potential of uranium-focused gamma-ray spectrometry for cobalt exploration in complex Pan-African geological contexts.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106038"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049143","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":"Geochemical evidence for a thermogenic oil-associated gas petroleum system for JDT field in Abu El Gharadig basin, Egypt","authors":"Mohamed A. Agamy ,&nbsp;Mahmoud Y. Zein El Din ,&nbsp;Mohamed M. El Nady ,&nbsp;Walid A. Makled","doi":"10.1016/j.jafrearsci.2026.106036","DOIUrl":"10.1016/j.jafrearsci.2026.106036","url":null,"abstract":"<div><div>This study presents a comprehensive geochemical assessment of rock samples and natural gas data to evaluate the petroleum system of the Abu El Gharadig Basin. The investigation focuses on the Upper Cretaceous Abu Roash (C –G) members and Middle Jurassic Khatatba Formation which represent the principal source rocks in the basin. Total organic carbon (TOC) and Rock-Eval pyrolysis analyses reveal significant organic richness, with TOC values reaching up to 3.14 wt%, and hydrogen index (HI) values peaking at 489 mg HC/g TOC indicative of Type II kerogen. This indicates a strong potential for liquid hydrocarbon generation. Thermal maturity parameters including Tmax (430–448 °C) and vitrinite reflectance (R_o = 0.50–0.92 %) confirm that these source rocks lie within the oil window, with deeper intervals approaching peak maturity. Geochemical characterization of natural gas from the Apollonia reservoir further supports this interpretation. The gases are gas associated with oil generation with elevated wetness and high ethane concentrations, indicating an association with condensates derived from the thermal cracking of liquid hydrocarbons. The absence of isotopic alteration suggests efficient migration and preservation. Basin modeling shows that hydrocarbon generation in the Abu El Gharadig basin began in the Early Cretaceous, with major oil-to-gas conversion occurring much later, and structural traps forming beforehand to secure these accumulations. Collectively, the results confirm a dynamic and effective petroleum system within the Abu El Gharadig Basin, with the Abu Roash and Khatatba formations as key hydrocarbon sources driving both generation and expulsion processes. Collectively, the results confirm a dynamic and effective petroleum system within the Abu El Gharadig Basin, where the Abu Roash and Khatatba formations as key hydrocarbon sources driving both generation and expulsion processes.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106036"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090370","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":"Lunar tidal cycle forcing on estuarine hydrodynamics and water quality patterns and implications for suspended sediment-borne contaminant transport: Case study of SE coast of Nigeria","authors":"Effiom E. Antia","doi":"10.1016/j.jafrearsci.2026.106044","DOIUrl":"10.1016/j.jafrearsci.2026.106044","url":null,"abstract":"<div><div>Knowledge of longevity of sediment-borne contaminants in estuaries is central to contingency planning of coastal regions worldwide. Inter-comparison of the response patterns of estuarine hydrodynamic and water quality parameters to tidal forcing at time scale of semidiurnal and lunar tidal cycle is crucial to this effort. Results of above parameters at two contiguous mesotidal estuaries (Imo River and Qua Iboe River) on the southeastern coast of Nigeria are presented based on synoptic monitoring of 50 successive semidiurnal tidal cycles. The time-series patterns of studied parameters in the estuaries showed considerable compatibility. Both estuaries displayed increased velocities (tidal peak, tidal stage-averaged and tidal cycle residual) and tidal cycle net excursion lengths with increase in tidal amplitude. Their transparency depths were shallowest at spring tides while water colour, pH and salinity were lowest at neap tides. The estuaries are prone to export sediment-borne contaminants on a long term, but at a faster rate at spring than neap tide. This is based on &gt; 80 % frequency of ebb-asymmetric net excursion length and averaged spring to neap tide net excursion length ratios of 2.1–2.4. Of wider application is the prospect of utilizing the predictive relations on contaminant import-export drivers to rank longevity of contaminants in comparable estuaries.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106044"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090368","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":"Depositional settings and basin-fill evolution of the restricted platform system on the Intra Pontide belt during the Late Eocene-?Early Oligocene transition, western black sea region, Turkey","authors":"Muhammed Sami Us ,&nbsp;Erdoğan Tekin ,&nbsp;Funda Akgün ,&nbsp;Mine Sezgül Kayseri-Özer ,&nbsp;Baki Erdoğan Varol","doi":"10.1016/j.jafrearsci.2026.106030","DOIUrl":"10.1016/j.jafrearsci.2026.106030","url":null,"abstract":"<div><div>This study presents an integrated sedimentological, microfacies, and palynological analyses of the Late Eocene–?Early Oligocene (Priabonian–?Rupelian) Akçapınar Formation, exposed along the Soğanlı Stream in the Intra-Pontide Belt of the Western Black Sea region, Turkey. The formation, which overlies the evaporitic Pürçükören Formation and locally the Soğanlı Formation, records deposition in restricted shallow-marine to a lagoonal setting during a phase of significant tectonic and climatic reorganization. Detailed field mapping and measured stratigraphic sections, supported by petrographic, XRD, and SEM analyses, reveal mud-supported textures, limited faunal diversity, and thin-shelled gastropods, consistent with low-energy, brackish conditions. Palynological assemblages, identified here for the first time, refine the age constraints and document freshwater influence, whereas mineralogical data indicate alternating arid (smectite-rich) and humid (chlorite–illite-rich) intervals. Microfacies patterns (Mf1–Mf4) and lithofacies associations (Lf1–Lf8) were synthesized into three-dimensional depositional models, illustrating progressive basin restriction, episodic subaerial exposure, and evaporite precipitation. The multi-proxy approach, integrating sedimentology, microfacies, palynology, and mineralogy, refined the depositional model of the Akçapınar Formation, revealing facies heterogeneity driven by the interplay of tectonically induced basin isolation, relative sea-level fluctuations, and paleoclimatic oscillations during the Eocene–Oligocene transition, and providing new insights into the paleogeographic evolution of the northern Neo-Tethys during the final stages of its closure.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106030"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090367","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 susceptibility records and sequence stratigraphy in shallow-water carbonates, fluvial-deltaic, and organic / phosphatic-rich deposits: Insights from the Paleogene-Neogene of Central and NE Tunisia","authors":"Jihede Haj Messaoud ,&nbsp;Hela Fakhfakh Ben Jemai ,&nbsp;Chokri Yaich ,&nbsp;Hanen Kamoun ,&nbsp;Sameh Khaled ,&nbsp;Zied Chikhaoui","doi":"10.1016/j.jafrearsci.2026.106024","DOIUrl":"10.1016/j.jafrearsci.2026.106024","url":null,"abstract":"<div><div>Magnetic susceptibility is recognized as a predictive tool in reservoir identification, mineral exploration, and sequence stratigraphy; however, its controlling factors in mixed carbonate–siliclastic systems remain insufficiently understood. This study aims to elucidate the primary drivers of magnetic susceptibility variability by examining carbonate and siliciclastic systems from central and northeastern Tunisia. We specifically assess the relationships between magnetic susceptibility, lithology, facies, and mineralogy, with attention to the modifying effects of diagenetic processes and the occurrence of phosphate and organic matter enrichment. Our methodological approach integrates high-resolution magnetic susceptibility measurements with detailed sedimentological logging, facies analysis, carbonate content, and mineralogical characterization. In siliciclastic-dominated systems, distal fine-grained sediments yield elevated magnetic susceptibility values due to higher concentrations of magnetic minerals. At the same time, coarser facies tend to exhibit lower or negative magnetic susceptibility values. In carbonate settings, elevated magnetic susceptibility values are typically associated with regressive phases, while reduced values are observed during transgressions. Diagenetic modifications exert a substantial impact on the magnetic susceptibility signal. Dolomitization typically reduces magnetic susceptibility by replacing magnetic-bearing carbonate mud with less magnetic dolomite crystals, diluting the original signal. Intervals with phosphate are often marked by enhanced magnetic susceptibility values, reflecting the concentration of iron-bearing phases associated with phosphate mineralization. Organic-rich layers exhibit a mixed magnetic susceptibility response: in some cases, magnetic susceptibility increases due to the formation or preservation of authigenic magnetite under reducing early diagenetic conditions, whereas in other cases, magnetic susceptibility decreases, likely reflecting the absence of magnetic mineral formation or their dissolution under highly anoxic conditions. These findings emphasize the complex interplay of factors influencing magnetic susceptibility and demonstrate its potential as a valuable tool for sequence stratigraphy and mineralogical exploration in both siliciclastic and carbonate settings.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106024"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090513","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":"Toward a refined framework for upper Albian-lower Turonian ammonite biostratigraphy: case study from the Aurès Basin (NE Algeria), and regional correlation with Western Europe, central Tunisia, and the Western Interior Seaway","authors":"Aida Bensekhria ,&nbsp;Mhammed Abdeldjalil ,&nbsp;Rabah Bouhata ,&nbsp;Meriem Khelali","doi":"10.1016/j.jafrearsci.2026.106046","DOIUrl":"10.1016/j.jafrearsci.2026.106046","url":null,"abstract":"<div><div>This study presents the first integrated interregional correlation of the upper Albian–lower Turonian stratigraphic record of the Aurès Basin (northeast Algeria) within a broad Tethyan–Atlantic framework, integrating lithostratigraphy, ammonite biostratigraphy, and palaeogeography based on three stratigraphically logged and sampled sections along a southwest–northeast transect. Four successive formations were identified: Grès Rouges, Taghrout Ameur Gray Marls, Zeouei, and Yabous formations, representing a continuous upper Albian to lower Turonian record. Eight ammonite biozones were identified and correlated: <em>Stoliczkaia</em>Interval Zone (upper Albian), <em>Mantelliceras</em> cf. <em>mantelli</em> Partial Range Zone (lower Cenomanian), <em>Mantelliceras dixoni</em> Interval Zone (upper-lower Cenomanian), <em>Cunnigtoniceras inerme</em> Interval Zone (Lower-middle Cenomanian), <em>Acanthoceras</em> cf. <em>rhotomagense</em> Interval Zone (middle Cenomanian), <em>Acanthoceras amphibolum</em> Total Range Zone (upper-middle Cenomanian), <em>Neolobites vibrayeanus/Eucalycoceras pentagonum</em> Total Range Zone (early upper Cenomanian), and <em>Pseudaspidoceras flexuosum</em> Interval Zone (lower Turonian). Comparative analysis of twelve biozones in Northwest Europe and nineteen in Western Interior reveals broad synchrony in zonal development, but also highlights palaeobiogeographic differentiation driven by climatic gradients, provincialism and marine barriers. The <em>Cunningtoniceras inerme</em> and <em>Conlinoceras tarrantense</em> Zones establish robust links with the Western Interior, whereas the absence of <em>P. flexuosum</em> in Boreal Europe marks a persistent Tethyan–Boreal faunal divide. Transgressive events and the opening of the South Atlantic broadened marine corridors along the Tethyan edge, facilitating ammonite dispersal and promoting both endemism and cosmopolitanism. The Oceanic Anoxic Event 2 (OAE2) had divergent biotic impacts, diminishing variety in Boreal Europe while preserving or enhancing it in North Africa and the Western Interior. Overall, the Aurès ammonite record demonstrates that the basin functioned as a key southern Tethyan palaeogeographic corridor, providing critical constraints for refining global ammonite biostratigraphic frameworks and understanding upper Albian-lower Turonian transcontinental marine connectivity.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"237 ","pages":"Article 106046"},"PeriodicalIF":2.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090369","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":"The late Neoproterozoic orogenic gold mineralization at the North Romite area, South Eastern Desert, Egypt: geological, geochemical, and structural constraints","authors":"Mahmoud E. Mesbah ,&nbsp;Eman I.M. Ibrahim ,&nbsp;Abdel-Kader M. Moghazi ,&nbsp;Hassan I. El Sundoly ,&nbsp;Mahmoud K. Alawy","doi":"10.1016/j.jafrearsci.2026.106023","DOIUrl":"10.1016/j.jafrearsci.2026.106023","url":null,"abstract":"<div><div>The North Romite area, in the South Eastern Desert of Egypt, comprises a structurally controlled gold deposit (up to 8.8 g/t Au) that shares several characteristics with orogenic gold mineralization. This deposit has not received attention in geological studies because it is buried beneath Recent sand deposits. Here, we present new field, structural, and geochemical data for the North Romite deposit to investigate its mineralogical and geochemical characteristics, as well as its relationship to the regional tectonic context. The host rocks of gold mineralization in the study area are late Neoproterozoic arc metavolcanics and metagabbro-diorite, which underwent greenschist facies metamorphism and deformation. The mineralized zones are represented by sheared and folded quartz/carbonate veins and wall rock alterations that extend along transpressional NNE-, NE- and NW-trending shear zones. These shear zones splay from the major post-accretionary N-S Hamisana zone that was formed by collisional tectonics during the final assembly of Gondwana ∼640–600 Ma. The wall rock alterations around the quartz veins contain chlorite and epidote in the distal zones and quartz-sericite-carbonate-pyrite-chalcopyrite-gold in the intermediate and proximal zones. The geochemical signature of the North Romite deposit is defined by a metallic association of Au- Ag-As, as indicated by the elevated contents of these elements in the proximal alteration zones. The lack of syn-tectonic magmatism and the intense deformation in the deposit area indicate that the fluids responsible for gold mineralization were produced by metamorphic devolatilization. Gold precipitation was most likely controlled by phase separation, accompanied by decreasing confining pressure and lowering pH.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106023"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034965","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":"Addressing the shear delay time log deficiency in the Timimoun Basin: A comparative study of AI algorithms and single attribute regression for geomechanical modelling","authors":"khalda ZABEL,&nbsp;mohamed cherif BERGUIG,&nbsp;rachid KETTEB","doi":"10.1016/j.jafrearsci.2026.106002","DOIUrl":"10.1016/j.jafrearsci.2026.106002","url":null,"abstract":"<div><div>The primary aim of this study is to build an anisotropic geomechanical model (AGM) using well log data from Frasnian-aged shale in the Algerian Timimoun Basin. However, the lack of a shear delay time log (DTS) in one of the six available wells limits AGM analysis, as it is crucial for quantifying mechanical properties. Thus, to address this limitation, two approaches are adopted. Artificial intelligence (AI) algorithms and the single attribute regression (SAR) method. The AI-based model was trained first by integrating multiple well log data as inputs. Then, it incorporates only the compressional delay time (DTC) log. Furthermore, SAR generates an empirical equation by cross-plotting the DTC log versus the DTS log from four wells where the DTS log is available. Model validation is applied to the fifth unseen well from the same field. As a result, the SAR was a good measurement of the target log, reflecting similar geological variation as the DTC log along the studied interval, with a strong correlation coefficient (R²) of 0.97. Otherwise, the AI algorithms indicate a reliable performance with high accuracy (R²) and low values of root mean square error (R²∼0.96, RMSE∼0.1) for the first training. Compared with the first run, the second run is less accurate (R²∼0.8, RMSE∼0.26). Moreover, the AI-based model produced logs lacking the detailed variability of actual measurements while reducing prediction error and noting the high-frequency variation of the outputs, which may be due to the regularization and averaging effects of the algorithms.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106002"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrological and geochemical evidence of new ophiolitic remnants in the Maghrebides chain (Moul ed Demamene Massif, north-eastern Algeria). Geodynamic implications","authors":"Ahmed Talhi ,&nbsp;Moulley Charaf Chabou ,&nbsp;Ahcene Bourefis","doi":"10.1016/j.jafrearsci.2026.106021","DOIUrl":"10.1016/j.jafrearsci.2026.106021","url":null,"abstract":"<div><div>The Moul ed Demamene massif is located within the suture zone between the internal and external zones of the Maghrebides chain in north-eastern Algeria. It contains a rare outcrop of Maghrebian flysch basement, including a complex of mafic rocks (gabbros and basalts). This study provides a detailed petrological and geochemical investigation of these rocks in order to constrain their origin and the geodynamic context of their emplacement within the framework of the Maghrebide orogeny. The studied rocks consist of gabbros, dolerites and basalts, which are predominantly composed of plagioclase, clinopyroxene (augite) and titanomagnetite. The altered mineral assemblages consist of albite, chlorite, epidote and actinolite, which are characteristic of greenschist-facies metamorphism of oceanic crust. Geochemical results indicate that the mafic rocks of the Moul ed Demamene massif have a homogeneous tholeiitic composition and a T-MORB affinity. This suggests that they formed during the initial stages of the oceanization of the Maghrebian Tethys basin. These rocks form the oceanic basement crust onto which the Maghrebian Mauretanian flysch was deposited. The Moul ed Demamene mafic rocks have a similar composition to T-MORB mafic rocks found in ophiolitic complexes in Corsica and the Texenna ophiolite in the western Mediterranean. Furthermore, this study suggests that the Boukredeche Formation of the Moul ed Demamene massif, comprising the studied mafic rocks and the Mauretanian flysch cover, is distinct from the Achaiches series. Until now, the Achaiches series was considered to be the only complete Paleozoic-to-Upper Jurassic basement in the Mauretanian flysch domain. The rocks of the Achaiches series probably originate from an eastern Tethyan terrane as they contain Triassic radiolarite, which is absent from the western Tethys. Finally, the mafic rocks of Moul ed Demamene constitute the second known ophiolitic outcrop remnant of the Maghrebides chain.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"236 ","pages":"Article 106021"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034961","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}