Journal of African Earth Sciences最新文献

{"title":"Petrography, geochemistry and geochronology of Aghirer Plutonic Granitoid Complex, Eastern Hoggar, Algeria","authors":"Hocine Zeghouane ,&nbsp;Abla Azzouni-Sekkal ,&nbsp;Jean Paul Liégeois ,&nbsp;Ahmed Serkhane","doi":"10.1016/j.jafrearsci.2025.105630","DOIUrl":"10.1016/j.jafrearsci.2025.105630","url":null,"abstract":"<div><div>The Assodé-Issalane terrane, situated in the southern region of Algeria, east of the Hoggar, is predominantly composed of Paleoproterozoic metamorphic rocks which were subjected to high-grade amphibolite to granulite facies metamorphism during the Pan-African orogeny, accompanied by large migmatization and granite emplacement. The easternmost region of the Raghane-8°30 shear zone exhibits evidence of the Eburnean orogeny (2.2–2.0 Ga) and multiple granitoid events, indicative of three major orogenic episodes: 800–820 Ma, extensional event (790, 730 Ma), a collision with the West African craton (660 Ma and 630-580 Ma), and a subsequent collision with the Murzuq craton (575-545 Ma), culminating in the regional metamorphism and stabilization of the eastern Hoggar. The present study focuses on the Aghirer Granitic Pluton (AGP), a late, circular granite intrusion that intrudes the 730 Ma Arirer granitic batholith and the Eberjegui basement of the Tadoumet region. A comprehensive suite of analytical techniques was employed, encompassing petrographic examination, geochemical assessment on ten samples obtained from the AGP, and Rb/Sr isotopic geochronological analysis on seven samples. Petrographic and geochemical analyses reveal a potassic calc-alkaline granite and granodiorite composition, suggesting a syn-collisional to late orogenic tectonic setting. Geochemical data indicate its affinity with the lower continental crust with minimal crustal contamination. Rb-Sr geochronology yielded an isochron age of 553 ± 20 Ma, recording the late Pan-African orogeny. The low initial ⁸⁷Sr/⁸⁶Sr ratio further supports the limited role of upper crustal contamination in the magma genesis. These findings provide crucial insights into the magmatic evolution and tectonic history of the Hoggar during the late Pan-African orogeny.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105630"},"PeriodicalIF":2.2,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680606","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":"AVO class II advanced prospectively workflow for deep miocene in west delta deep marine, offshore Nile Delta, Egypt","authors":"Ramy Fahmy ,&nbsp;Manal El Kammar ,&nbsp;Aia Dahroug ,&nbsp;Nadia Abd-Elfattah","doi":"10.1016/j.jafrearsci.2025.105634","DOIUrl":"10.1016/j.jafrearsci.2025.105634","url":null,"abstract":"<div><div>The West Delta Deep Marine (WDDM) region offshore the Nile Delta in Egypt, which contains significant Pliocene fields, is currently experiencing a decline in production, leading to the exploration of deeper Miocene targets. To tackle this challenge, a proposed an enhanced workflow that utilized sophisticated AVO analysis to detect subtle gas reservoirs within the Miocene strata, corroborated by Direct Hydrocarbon Indicators (DHIs). Prior wells aimed at Messinian and earlier strata frequently encountered water-bearing sands, displaying AVO Class I responses with hard kicks, thereby complicating reservoir differentiation. Our methodology initiates with extensive rock physics modeling to evaluate the potential for AVO Class II responses in Miocene sediments. Fluid substitution techniques and stochastic Monte Carlo simulations were utilized to model gas-bearing responses, with minor amplitude variations in far-offset stacks confirming feasible AVO Class II gas sand scenarios. The seismic analysis of the WDDM region identifies reservoir attributes within an aggradational channel system, shaped by structural elements including the Rosetta fault and offshore anticlines of the Nile Delta. Through the integration of sophisticated DHI support and geological derisking methodologies, multiple promising AVO Class II prospects displaying clear soft kick signatures were identified. These findings improve the success rate for new Miocene exploration targets by accurately differentiating gas sands from water sands, even in instances of weak seismic responses, and offer a framework applicable to analogous deepwater basins with clastic reservoirs and diverse AVO characteristics.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105634"},"PeriodicalIF":2.2,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680608","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":"Pixel-wise feature fusion in gully susceptibility: A comparison of feed-forward neural networks and ensemble (voting, stacking) models","authors":"Vincent E. Nwazelibe ,&nbsp;Johnson C. Agbasi ,&nbsp;Daniel A. Ayejoto ,&nbsp;Johnbosco C. Egbueri","doi":"10.1016/j.jafrearsci.2025.105633","DOIUrl":"10.1016/j.jafrearsci.2025.105633","url":null,"abstract":"<div><div>Similar to other geologic hazards, gullies pose significant challenges to Nigeria's southernmost State, requiring a reliable susceptibility mapping analysis to support decision-making. However, challenges exist regarding model recommendations, especially in studies utilizing multiple models that perform well but show visual differences, necessitating the fusion of pixel-wise features from base model predictions to present a single useable map. Although hybridised models exist, they often produce results by pairing models rather than fusing multiple model outcomes. While stacking and voting approaches could address this problem, they have remained relatively unexplored. Using a fully connected feed-forward neural network (FNN) with ensemble voting and stacking methods as pixel-wise feature fusions, this study seeks to answer these questions: How can multiple base machine learning (ML) models (Bagging, Random Forest (RF) and Extreme Gradient Boosting (XGB)) be combined? Do they improve accuracy compared to base models? How do fusion methods differ and generalize to new data? Thirteen (13) conditioning factors were used alongside complex k-fold cross-validation, training, and testing inventory structure of 574 gully and non-gully points. Our k-fold validation and testing results of the Area under the Receiver Operating Characteristic Curve (AUC) and Mean Absolute Error (MAE) show that FNN (AUC: 0.9666 &amp; 0.9670; MAE: 0.1432 &amp; 0.1616) strengthens the base model and generalises better than stacking (AUC: 0.9821 &amp; 0.9598; MAE: 0.0703 &amp; 0.1604) and voting (AUC: 0.9990 &amp; 0.9752; MAE: 0.0532 &amp; 0.1485) but requires parameter optimization. The study expands the knowledge about the fusion of ML methodologies within geospatial analysis and advances gully-related literature within the study area to support mitigation strategies.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105633"},"PeriodicalIF":2.2,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680610","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":"Inception and evolution of the Turkana Depression: A review from the perspective of the longest-lived sector of the East African Rift","authors":"C.K. Morley ,&nbsp;S.C. Boone","doi":"10.1016/j.jafrearsci.2025.105625","DOIUrl":"10.1016/j.jafrearsci.2025.105625","url":null,"abstract":"<div><div>The Turkana Depression comprises a highly anomalous sector of the East African Rift (EAR), distinct in its antiquity, structural complexity, geomorphology and attenuated crustal architecture. Previous studies inferred these distinctions derive from pre-existing lithospheric heterogeneities, especially Cretaceous–early Paleogene Central African Rift (CAR) tectonism. Yet, Paleogene extensional deformation is neither clearly typical CAR, nor EAR. Instead, extension gradually evolved from primarily plate-driven (slab pull), to a hybrid state where mantle plume-related (active) processes became increasingly important (particularly c. 23- 7 Ma) to one after c. 7 Ma where active rifting processes dominate. Significant extension accommodated by dyke intrusion in Turkana probably didn't begin until the Pleistocene, accompanied by basin inversion. From c. 30 Ma extension transitioned from the CAR to the Gulf of Aden-Red Sea (GARS) region, marked by Late Oligocene inversion in the CAR trend and parts of Turkana (recorded by outcrop geology and low-temperature thermochronology). Neotethys slab pull helped drive Cretaceous-Palaeogene extension, but was gradually eliminated by the Zagros collision (Early Miocene?) and diachronous opening of the GARS spreading centres (Middle Miocene). Across this transitional period, seismic reflection data indicates total upper crust Cenozoic extension is &lt; 40 km. Conversely, Moho topography suggests &gt;120 km extension. Given the absence of major Cretaceous basin development in western Turkana, probably pre-Cretaceous thinning and/or initially thin crust is required to explain the discrepancy. Turkana Eocene-Miocene extension rates were variable, but low (c. 1 mm/yr) before Plio-Pleistocene acceleration to Holocene-Recent rates of c. 4–5 mm/yr. The CAR, with its very limited volcanism and three phases of extension, separated by inactive periods and crustal cooling, challenges the idea that East African lithosphere is too strong to extend without a plume or magma assistance. However, mantle-weakening, magma-assisted processes accompanying early mantle plume activity probably operated at depth in the western Turkana Depression from c. 40–55 Ma onwards, and may explain the onset of Palaeogene rifting.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105625"},"PeriodicalIF":2.2,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680604","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 Pliocene of the Western High Atlas (Morocco). Biostratigraphical, sedimentological and palaeogeographical characterisations","authors":"Aziz El Badri ,&nbsp;Moussa Masrour ,&nbsp;Ahmed El Mouden ,&nbsp;Fouad Khiri","doi":"10.1016/j.jafrearsci.2025.105610","DOIUrl":"10.1016/j.jafrearsci.2025.105610","url":null,"abstract":"<div><div>This study addresses the Pliocene of the Western High Atlas (WHA), Morocco, using sedimentological and biostratigraphical data to reveal its palaeogeographical characteristics. Stratigraphic sections analysed along an east - west transect from Dar Boubaker to Tildi demonstrate that the Pliocene strata lie unconformably over the Chattian-Aquitanian white conglomeratic deposits. Two distinct facies units, designated U1, and U2 respectively, have been identified within the Pliocene succession. The first of these, designated as U1, consists of an infralittoral facies of greyish sandstone in the easternmost region, which turns into circalittoral sandy-marly molasse in the westernmost region, with interbeds of yellowish, fossiliferous sandy limestone. The second facies unit, designated as U2, shows an initial conglomeratic character in the eastern region, accompanied by intercalations of infralittoral limestone and sandstone in its basal part. However, towards the far eastern region, specifically at Ighzer n'Kourir, U2 turns into a continental setting. Westwards, U2 becomes molassic and infralittoral, showing a deeper facies. The distribution of Pliocene fossils in the study area indicates that the water temperature varied from warm to cold. The Quaternary facies is defined by stratigraphic unconformities, the development of alluvial fans and biostratigraphical markers, including the appearance of Quaternary echinoids and the extinction of <em>Turritella aspera</em> Mayer, 1868. The macrofauna includes bivalves, gastropods, bryozoans, cirripeds, echinoids, bones, and selachian remains. The benthic microfauna is dominated by the <em>Ammonia beccarii</em> Linnaeus, 1758 and <em>Elphidium crispum</em> Linnaeus, 1758. Palaeogeographically, U1 is associated with a post-Messinian transgressive phase, whereas U2 formed in a regressive environment, with littoral facies in the westernmost region and fluvial-lacustrine facies to the east of Ighzer n'Kourir, correlating with the lower Pleistocene. The Pliocene Sea has been filled in with continental molasse sediments, which originated from the Alpine orogeny.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105610"},"PeriodicalIF":2.2,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680523","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":"Reservoir evolution and property prediction of the Paleogene Apollonia Formation, Western Desert, Egypt","authors":"Yongjie Hu ,&nbsp;Hong Zhang ,&nbsp;Zixuan Liu ,&nbsp;Edgar Cross ,&nbsp;Ying Li ,&nbsp;Shuyuan Shi ,&nbsp;Hongxia Liu ,&nbsp;EmadEldin Ramy ,&nbsp;Rongtu Ma ,&nbsp;Chunfang Cai","doi":"10.1016/j.jafrearsci.2025.105631","DOIUrl":"10.1016/j.jafrearsci.2025.105631","url":null,"abstract":"<div><div>The shallow-burial Neo-Tethys Cenozoic reservoirs host significant hydrocarbon resources. However, a limited understanding of the Paleogene Apollonia Formation, north Western Desert, Egypt, hinders further exploration and development. Here, RZK, WD33 and JD blocks were analyzed using a combination of petrological observations, petrophysical analysis, well logging analysis, machine learning, and deep learning. Five types of limestone and two types of dolostone were identified. Planktonic and benthic foraminifera (e.g., <em>Nummulite</em>) are well-developed. The sedimentary facies consists of grain shoals, shallow to deep ramp and deep-water slope facies. Grainstone and packstone from high-energy sedimentary environments yield high primary porosity and permeability. Dolomitization and bacterial sulfate reduction further enhance reservoir properties. Framboidal and granular pyrites are well-developed here. The reservoir spaces consist of framework pores, inter-granular pores, intra-granular pores, moldic pores, inter-crystalline pores, and fractures. The sedimentary facies and diagenetic history indicate that WD33 and RZK (esp. ERZK &amp; MRZK) blocks exhibit promising reservoir performance. Drilled cores of three wells from different sedimentary facies served as the training dataset for machine learning and deep learning, while two core wells were utilized as the test group. Using XGBOOST, Random Forest, and Long Short-Term Memory algorithm, the predicted porosity values closely match core-measured values, with R² (coefficient of determination) values of 0.72, 0.58, and 0.61, respectively. The permeability prediction results also yield similarity to the measured values. The Jurassic and Cretaceous source rocks generated hydrocarbon for the overlying Paleogene <em>Nummulite</em> carbonate reservoirs in the Neo-Tethys domain. This study provides valuable insights into carbonate reservoirs in the north Western Desert and holds significance for global Cenozoic carbonate exploration and development.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105631"},"PeriodicalIF":2.2,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680609","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":"A palaeoenvironmental reconstruction of the Campanian‒lower Palaeocene succession of the Dakhla Oasis (Western Desert, Egypt): Insights from integrated sequence stratigraphy, macrobenthos, and trace fossil analyses","authors":"Sara Zahran ,&nbsp;Magdy El Hedeny ,&nbsp;Ahmed El-Sabbagh ,&nbsp;Mohamed Rashwan ,&nbsp;Ahmed El-Refaiy ,&nbsp;Gebely Abu El-Kheir","doi":"10.1016/j.jafrearsci.2025.105629","DOIUrl":"10.1016/j.jafrearsci.2025.105629","url":null,"abstract":"<div><div>The palaeoenvironments of the Campanian‒lower Palaeocene composite succession in the Dakhla Oasis, Egypt, are interpreted based on the integration of sequence-stratigraphy, macrobenthic associations, and trace fossils. This succession comprises six rock units, corresponding to several transgression-regression cycles. These rock units include the Quseir Formation, the Duwi Formation, and the Mawhoob, Beris, Lower Kharga, and Upper Kharga members of the Dakhla Formation. Six unconformities delineate seven 3rd-order depositional sequences, including the lower‒middle Campanian DS-Q1, the upper Campanian DS-D1 and DS-D2, the lower Maastrichtian DS-Dk1, the upper Maastrichtian DS-Dk2 and DS-Dk3, and the lower Danian DS-Dk4. The invertebrate macrobenthic elements sporadically occurred throughout the studied succession, representing three bivalve associations: the late Campanian <em>Nicaisolopha</em>-<em>Plicatula</em> association, the late Maastrichtian <em>Exogyra overwegi</em> association, and an early Danian <em>Venericardia</em> association. At least 12 ichnotaxa have been identified, representing two ichnoassemblages: the late Campanian <em>Thalassinoides</em>-<em>Psilonichnus</em> and the latest Maastrichtian‒early Danian <em>Rhizocorallium jenense</em>-<em>Tisoa siphonalis</em>, both belonging to the <em>Glossifungites</em> Ichnofacies. Sequences characteristics indicate palaeoenvironments ranging from brackish, littoral, and near-shore to inner and outer neritic settings, reflecting the influence of syn-sedimentary tectonics combined with sea-level fluctuations, which resulted in varied depositional features. The distribution and the trophic structure of the body and trace fossil assemblages confirm the role of several environmental parameters, such as substrate characteristics, bathymetry, water energy, productivity level, sedimentation rates, and oxygen availability, in shaping the occurrence of different elements within these faunal assemblages.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105629"},"PeriodicalIF":2.2,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642950","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 Cenozoic updated foraminiferal stratigraphic and palaeoenvironmental framework for the southwestern shelf of Africa","authors":"Mabrouk Bachari ,&nbsp;Daniël Louw ,&nbsp;Jared T. Walsh ,&nbsp;Petrus le Roux ,&nbsp;Susanne Fietz ,&nbsp;Eugene W. Bergh","doi":"10.1016/j.jafrearsci.2025.105632","DOIUrl":"10.1016/j.jafrearsci.2025.105632","url":null,"abstract":"<div><div>Marine sediments from the western shelf of southern Africa provide key information on the stratigraphy and palaeoenvironment of the region. Palaeoenvironmental research on Miocene shelf foraminifera is fragmentary. An understanding of the stratigraphy and palaeoenvironment can inform on exploration studies and climatic impact on marine sedimentation. Two marine cores (core 128 at 262 m; core 1408 at 303 m water depth) from the western shelf of South Africa and Namibia were studied for their strontium isotope (⁸⁷Sr/⁸⁶Sr ratios) stratigraphy, foraminiferal biostratigraphy and microscopy. Five depositional units based on their sedimentary and mineral compositions occur in core 128, namely: foraminifera-rich sand; black pelletal phosphorite unit I; glauco-phosphatic unit; calcareous glauco-phosphatic unit and black pelletal phosphorite unit II. Core 1408 contained three main units, namely: foraminifera-rich mud; brown-black phosphorite unit and shelly phosphorite unit. The palaeoenvironment of core 128, based on foraminiferal ecological indicators, show a relatively deeper marine, nutrient-rich environment in the early Miocene (20.45 Ma; indicator species <em>Globigerina praebulloides</em> and <em>Globigerina falconensis</em>), while late Miocene foraminifera in the basal foraminifera-rich mud unit (9.80–5.80 Ma; indicator species <em>Globoquadrina dehiscens</em>) of core 1408 revealed a slightly more oxygenated environment with warmer conditions. Phosphorites and shallow water foraminifera dated to the Pleistocene (2.72–1.09 Ma; indicator species <em>Globoconella inflata</em> and <em>Globorotalia truncatulinoides</em>) in both cores indicate eutrophic conditions and high productivity. Fragmentation of tests (19–54 %) are interpreted to be as a result of upwelling and transport under increasing sea-level amplitude. These two records support key environmental characteristics from upwelling conditions and major temperate water influence in the early Miocene to major fluvial influence in the Pliocene, and strong upwelling and eutrophic conditions in the Pleistocene.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105632"},"PeriodicalIF":2.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680607","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":"Eocene subvolcanics with slab failure magmatism affinity in the Samakhon area, NE Iran: Evidence of Pre-Lutecian collision of the Central Iran and the Eurasian Plates","authors":"Bahareh Borouzi Niyat ,&nbsp;Azadeh Malekzadeh Shafaroudi ,&nbsp;Hossein Azizi ,&nbsp;Mohammad Hassan Karimpour ,&nbsp;Yoshihiro Asahara ,&nbsp;Behnam Rahimi","doi":"10.1016/j.jafrearsci.2025.105624","DOIUrl":"10.1016/j.jafrearsci.2025.105624","url":null,"abstract":"<div><div>Porphyritic monzogranite and diorite considered as subvolcanic bodies are exposed in northeastern Iran as stocks and dikes in the Samakhon region. Zircon U–Pb dating yields ages ranging from 48.2 to 42.9 Ma for these rocks. Whole rock chemistry shows large variation of SiO₂ (54.6–65.4 wt %), MgO (0.19–5.49 wt %), and the alkaline elements contents (Na₂O + K₂O = 5.54 to 7.53 wt %), and display a positive Eu anomaly (Eu/Eu∗ = 0.95–1.2). High contents of the large ion lithophile elements (e.g., Sr, Rb, Cs, and Ba), high LREE/HREE ratios (La_N/Yb_N = 0.9–1.4), and negative Ta, Nb, and Ti anomalies are consistent with the calc-alkaline magmatic series emplaced along active margins. The initial ⁸⁷Sr/⁸⁶Sr ratios and εNd_i values change from 0.7052 to 0.7063, and from −3.0 to −0.4, respectively suggesting the involvement of crustal components in the sources of these rocks. Nb/Y (1.5), Gd/Yb (2.9), La/Yb (24.8), Sm/Yb ratios (3.3), and Nb abundances (15.1–19.9) are high compared to typical arc magmatism, suggesting that these rocks are likely associated with slab failure. The metasomatic mantle above the subduction zone in a pre-to post-collisional regime is the most likely candidate for the sources of these rocks. The development of the Sabzevar Cretaceous arc-related magmatism and the situation of the Samakhon subvolcanic rocks with younger age (48-42 Ma) in the northern Sabzevar suture zone, can be attributed to slab failure magmatic activity after the collision between the Central Iran Block and the Eurasian plate during the Early Eocene. The current model suggests that the closure of the Sabzevar ocean and the collision in northeastern Iran happened earlier than formerly assumed, which was previously thought to have occurred in the Late Eocene.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105624"},"PeriodicalIF":2.2,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643463","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":"Assessment of synthetic zeolites from kaolin and bentonite clays for wastewater and fuel gases treatment","authors":"Ahmed Abdelhalim ,&nbsp;Ahmed Melegy ,&nbsp;Dina Othman","doi":"10.1016/j.jafrearsci.2025.105621","DOIUrl":"10.1016/j.jafrearsci.2025.105621","url":null,"abstract":"<div><div>The present study evaluates the synthesis, geochemical and mineralogical characterization, as well as the industrial and environmental applications of zeolites synthesized from kaolin and bentonite resources in selected clay deposits of Northeast Africa, Egypt. Several methods were employed to synthesize zeolites from both kaolin and bentonite samples to obtain high purity zeolitic products at a competitive cost. The characterization of the synthesized zeolites, in terms of mineralogy and geochemistry, was conducted using various techniques, including X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and cation exchange capacity (CEC). Additionally, thermo-analytical methods such as thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used. Based on the characterization of zeolites synthesized from bentonite and kaolin, a comparison was made with ideal zeolites used in various industries to determine their potential applications. The synthesized zeolites were evaluated for their effectiveness as adsorbents for H₂S in wastewater and fuel gas purification. Additionally, they were assessed for their ability to remove ions such as Co²⁺, Sr²⁺, and Cs⁺ from aqueous solutions containing organic and suspended solids. Furthermore, these zeolites were investigated for their potential use as commercial and sustainable catalysts for controlling nitrogen oxide (NOx) emissions from diesel engines in vehicles.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"227 ","pages":"Article 105621"},"PeriodicalIF":2.2,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637474","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}