Journal of African Earth Sciences最新文献

{"title":"Petrogenesis of late Cretaceous granitoids in Gemici (Elazığ-Türkiye): evidence from whole-rock geochemistry, Sr–Nd isotopes, zircon U–Pb dating, and trace elements","authors":"Abdullah Sar","doi":"10.1016/j.jafrearsci.2025.105782","DOIUrl":"10.1016/j.jafrearsci.2025.105782","url":null,"abstract":"<div><div>The late Cretaceous granites and granodiorites are exposed in the Gemici area of Elazığ Province (eastern Türkiye). Here, we present recent whole-rock major oxide, trace element and Sr<strong>–</strong>Nd isotopic analyses, as well as zircon U<strong>–</strong>Pb data and trace element data of granitoids from the Southeastern Anatolian Orogenic Belt (SAOB) in eastern Türkiye. This paper aims to investigate the petrogenesis of the late Cretaceous granite and granodiorites (Gemici/Elazığ) using new and previously existing geochemical and geochronological data. Geochemical data indicate that the studied granites and granodiorites vary in composition from metaluminous to peraluminous, exhibit tholeiitic-calc-alkaline characteristics, and belong to the I-type granite. m. The Th/U ratios of zircon grains suggest a magmatic origin. Negative Eu and positive Ce values in zircon grains are indicative of unaltered magmatic zircons. The studied rocks exhibit a narrow range of ⁸⁷Sr/⁸⁶Sr_(i) ratios (0.704369–0.706019), and εNd_(t) values vary from 2.9 to 6.2, yielding model ages (T_DM) ranging from 841 to 1421 Ma. The energy-constrained assimilation-fractional crystallization (EC-AFC) modelling shows that the studied granite and granodiorites contain 1 %–5 % crustal melt contributions. Geochemical data indicate that subduction zone magmatism plays an active role in the petrogenesis of the studied rocks.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105782"},"PeriodicalIF":2.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714442","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 evolution of the Boni shear zone (BoSZ): Implications for gold mineral exploration in southwestern Burkina Faso","authors":"Fayçal Aziz Tarnagda ,&nbsp;Sâga Sawadogo ,&nbsp;Benjamin Sawadogo ,&nbsp;Abdoul Razack Ouédraogo ,&nbsp;Pascal Ouiya ,&nbsp;Stéphane Perrouty","doi":"10.1016/j.jafrearsci.2025.105778","DOIUrl":"10.1016/j.jafrearsci.2025.105778","url":null,"abstract":"<div><div>The Boni Shear Zone (BoSZ) has garnered significant interest from the geological exploration community following the Siou gold deposit discovery in the Mana gold district, southwestern Burkina Faso. The BoSZ represents a sheared contact separating the “Tarkwaian-type” metasedimentary sequences and the “Birimian-type” metavolcanic and metavolcano-sedimentary assemblages of the Houndé belt. The primary objective of this work is to elucidate the structural setting of the BoSZ and its control on gold mineralization. To achieve this, field work data, airborne geophysical data and satellite images have been interpreted and integrated. The initial deformation phase (D₁) occurred as an E-W directed regional shortening. Subsequent phase (D₂) developed transpressional dynamics under a NNW-SSE shortening, which is mainly documented within shear-zone-hosted coarse-clastic metasedimentary rocks. The last and minor phase (D₃) developed a minor crenulation cleavage. Several sets of shear zones formed during D₂: the older set is the NE-trending dextral strike-slip Bagassi shear zones (BaSZ). The main set, of regional extent, corresponds to the N-S trending sinistral transpressive Boni shear zones (BoSZ). It includes an anastomosing network of mylonite alternating with undeformed macro/microlithons. The last set, possible conjugate with the BoSZ, is localized nearby the Bagassi pluton and consists of the brittle-ductile NW-trending sinistral Yaramoko shear zones (YaSZ). All sets hosts gold mineralization.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105778"},"PeriodicalIF":2.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686877","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 rock typing and origin of oil in the Cretaceous post-rift mixed siliciclastic-carbonate of Abu Roash Formation, Badr El-Din 2 field, north Western Desert, Egypt","authors":"Mahmoud Leila ,&nbsp;Emad A. Eysa ,&nbsp;Mohammad Elbastawesy ,&nbsp;Fatma Ramadan ,&nbsp;Elham Elsobky","doi":"10.1016/j.jafrearsci.2025.105774","DOIUrl":"10.1016/j.jafrearsci.2025.105774","url":null,"abstract":"<div><div>Mixed siliciclastic-carbonate depositional sequences represent highly prospective targets for hydrocarbon exploration. These sequences commonly host reservoir facies characterized by both intergranular and secondary porosity, and they may be actively charged by intra-formational source rock organofacies. In the coastal rift basins of the Western Desert, the Upper Cretaceous post-rift succession of the Abu Roash Formation was deposited in environments ranging from shallow to deep marine settings. However, the existence of an intra-Abu Roash petroleum system has not been well-documented to date. This study integrates organic geochemical data with detailed petrophysical analysis to elucidate the origin of the hydrocarbons and to characterize the reservoir rock types (RRTs) within the mixed siliciclastic-carbonate facies of the Abu Roash Formation in wells from the BED-2 Field. Geochemical data reveal that the Abu Roash oil was sourced from a mixed Type II/III kerogen, with a greater contribution from marine organic matter. The oil exhibits a regular sterane distribution pattern of C₂₉ &gt; C₂₈ &gt; C₂₇, indicative of derivation from a mixed marine and terrestrial source rock. Moreover, the Abu Roash oil shows a clear negative correlation with Jurassic and Cretaceous oil families from adjacent basins but demonstrates a strong geochemical affinity with bitumen extracts from Abu Roash mudstones.</div><div>Depositional facies analysis indicates that the Abu Roash mixed siliciclastic-carbonate facies were deposited in a shallow marine setting, characterized by alternating tidal channel sandstones, lagoonal carbonates, upper shoreface, tidal inlet, and tidal flat facies, capped by lower shoreface to offshore mudstones. Petrophysical analysis identifies five distinct RRTs, with the highest reservoir quality (RRT1) associated with tidal channel sandstones. In contrast, the lagoonal carbonates exhibit highly heterogeneous reservoir properties, acting as micro-conduits and baffles to fluid flow. Notably, approximately 60 % of the reservoir's fluid flow capacity is attributed to the tidal channel facies of RRT1, while lower shoreface to offshore mudstones serve as effective sealing rocks. The findings of this study confirm the presence of an intra-Abu Roash petroleum system in the study area, thereby opening new opportunities for hydrocarbon exploration across the broader north Western Desert province. Moreover, the results of this study underscore the broader exploration significance of mixed carbonate–siliciclastic depositional systems globally hosting high-quality reservoir flow units, source rock organofacies, and effective seal rocks.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105774"},"PeriodicalIF":2.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653571","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 In Ezzane volcanic field (Eastern Hoggar, Algeria) and its enigmatic circular structures","authors":"Bernard Bonin ,&nbsp;Jean-Paul Liégeois ,&nbsp;Aziouz Ouabadi ,&nbsp;Olivier Bruguier ,&nbsp;Cees Passchier ,&nbsp;Hervé Guillou ,&nbsp;Nachida Abdallah ,&nbsp;Nassima Fezaa ,&nbsp;Rabah Laouar ,&nbsp;Jean Boissonnas","doi":"10.1016/j.jafrearsci.2025.105775","DOIUrl":"10.1016/j.jafrearsci.2025.105775","url":null,"abstract":"<div><div>The In Ezzane region, located in eastern Algerian Sahara, close to Libya – Niger border, is marked by late Pliocene and Pleistocene volcanism and by a remarkable group of circular structures, 4–9 km in diameter, situated on a basement composed of Tassili Cambrian-Ordovician sandstones. Both manifestations are imbricated and can only be subcontemporaneous. In this study, first, we date and characterize the volcanism and second, we try to constrain the origin of the circular structures that were visited just before the region closed for security reasons. Two basaltic lavas were dated at 2.01 ± 0.05 Ma (Gelasian) and at 1.49 ± 0.03 Ma (Calabrian) by K-Ar method. Petrographic investigations show that most volcanic rocks are basanites composed of olivine and Al-Ti diopside phenocrysts with xenocrystic mantle olivine and orthopyroxene. Temperatures of eruptions (1200–1300 °C) and of primary picritic magma (1500–1600 °C, i.e. a depth of 120–150 km), along with major and trace elements, and Sr-Nd isotopes all point to an asthenospheric source along the western lithospheric margin of the Murzuq craton (Murzuq volcanic province). The In Ezzane counter-relief circular structures are nested and NNW-SSE aligned, with each structure being truncated by the next one to the south-south-east. Up to 500 m outside circular structures, Tassili sandstones are reddened, dissected by intense fractures that are filled with fine-grained brown material and newly formed acicular white quartz, and often show white, cm-size, vesicles. The rims of the circular structures are composed of densely brecciated sandstones with dark veins, whereas the central parts are crosscut by a loose network of dyke-like dark veins. Microscopic observations, SEM imagery, SEM-EDS determinations and laser-ICP-MS chemical analyses of hydrothermal breccia components point to large masses of fluids having moved rapidly at shallow depths and having induced hydrofracturing of the heated sandstones with the generation of veins composed mostly of iron oxide. The viability of various processes that may have induced these large circular structures, i.e. tectonic reliefs, igneous and associated hydrothermal phenomena, meteorite impact craters, are discussed and favour sandstone karst features.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105775"},"PeriodicalIF":2.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704058","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 hybrid approach for accurate geothermal temperature prediction in the western region of Yemen","authors":"A.A. Al-Gathe ,&nbsp;Abbas Al-Khudafi ,&nbsp;G.M. Hamada ,&nbsp;Nasser Almuafa ,&nbsp;Ibrahim A. Farea ,&nbsp;Anwar Abdullah","doi":"10.1016/j.jafrearsci.2025.105777","DOIUrl":"10.1016/j.jafrearsci.2025.105777","url":null,"abstract":"<div><div>The growing need for clean and reliable energy sources has propelled geothermal energy to the forefront of research. Its inherent advantages of baseload power generation and minimal environmental impact make it a highly attractive option. Nonetheless, effective utilization of geothermal resources relies heavily on the ability to accurately predict subsurface temperatures within geothermal reservoirs.</div><div>In Yemen, a critical barrier to geothermal development is the lack of robust empirical correlations for predicting these crucial temperatures. This study presents a novel approach by developing a hybrid Particle Swarm Optimization Neural Network) PSONN (model to overcome this challenge.</div><div>A dataset encompassing 1402 data points was collected from 108 geothermal wells located in Yemen's western region. The model incorporates key parameters influencing geothermal temperatures as inputs, including: Latitude; Longitude, Temperature gradient, Surface temperature, Depth, Elevation. Subsurface temperature serves as the model's output variable. The data were then strategically divided into two sets: 70 % designated for training the PSONN model and 30 % reserved for subsequent testing and validation of its predictive capabilities. The research successfully establishes the PSONN model as a highly effective tool for subsurface temperature prediction. This is supported by the exceptionally low Average Absolute Percent Relative Error (APRE) of 0.541, indicating a minimal deviation between predicted and actual values. Additionally, the low Standard Deviation (SD) of 0.11 signifies a high degree of consistency in the model's predictions. The findings suggest that the PSONN model achieves high predictive accuracy, with performance metrics (e.g., APRE = 0.541, SD = 0.11, R = 0.999) comparable to or exceeding those reported in prior studies (e.g., Haklidir, 2019; Altay et al., 2022). Further comparative analysis with existing methods is warranted to fully establish its relative advantages<strong>.</strong></div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105777"},"PeriodicalIF":2.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663617","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":"Neoproterozoic continental arc magmatism along the northern Gondwanan Margin: Geochemistry and U–Pb geochronology of felsic intrusions from the eastern Taurides, Southern Turkey","authors":"Nil Yapıcı ,&nbsp;Nusret Nurlu ,&nbsp;Hakan Güneyli ,&nbsp;Hande Sonsun ,&nbsp;Abdulkadir Ürünveren","doi":"10.1016/j.jafrearsci.2025.105781","DOIUrl":"10.1016/j.jafrearsci.2025.105781","url":null,"abstract":"<div><div>The Eastern Taurides of southern Turkey represent a critical segment of the peri-Gondwanan margin, yet their Neoproterozoic magmatic history remains largely unconstrained. This study presents the first integrated geochemical and geochronological dataset from felsic subvolcanic intrusions—including granodiorite porphyry, tonalite porphyry, microgranodiorite, and aplite dikes—that intrude the Precambrian metasedimentary rocks of the Oruçlu Formation. Field observations reveal polyphase magmatic emplacement with features such as chilled margins, stoped metasedimentary enclaves, and post-emplacement deformation, suggesting crystallization in a tectonically active arc setting. Whole-rock geochemistry indicates metaluminous, high-K calc-alkaline signatures with enrichment in LILEs (Rb, Th, U, Pb) and depletion in HFSEs (Nb, Ta, Ti), consistent with I-type granitoids derived from a subduction-modified mantle source. Low Sr/Y ratios and the absence of adakitic signatures point to magma genesis at moderate crustal depths without garnet residue, typical of continental arc systems. A U–Pb zircon crystallization age of 642.2 ± 7.5 Ma confirms emplacement during the early Cadomian orogeny, coinciding with the onset of Proto-Tethys Ocean subduction. The Horzum felsic intrusions show close geochemical similarities to other Ediacaran–Cambrian granitoids in the Bitlis Massif, NW Turkey, and Iran, supporting the existence of a regionally extensive, Andean-type continental arc system along the northern margin of Gondwana. These results contribute to bridging a key spatial and temporal gap in the Neoproterozoic magmatic record of the Eastern Mediterranean region and provide new constraints on crustal evolution along the peri-Gondwanan margin. Despite their limited exposure and volume, these intrusions provide critical new constraints on Cadomian magmatism in southern Turkey, and establish the northern Gondwanan margin as a key locus of Neoproterozoic crustal growth in the Eastern Mediterranean region.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105781"},"PeriodicalIF":2.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686895","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":"Implications of gravity derivative filters and residual geoid on crustal deformations in the Anambra Basin, Southeast Nigeria","authors":"Emeka Epuh ,&nbsp;Ikenna Arungwa ,&nbsp;Ojima Apeh ,&nbsp;Adetoyinbo Adegoke ,&nbsp;Theddeus Akano ,&nbsp;Habib Olagunju ,&nbsp;Michael Orji ,&nbsp;Olagoke Daramola ,&nbsp;Chukwuma Okolie ,&nbsp;Isaac Idoko ,&nbsp;Robert Tenzer","doi":"10.1016/j.jafrearsci.2025.105769","DOIUrl":"10.1016/j.jafrearsci.2025.105769","url":null,"abstract":"<div><div>Analysis and interpretation of gravity data and its derivatives can provide valuable information on edge detection, geological structures, and deformation patterns. This study delineates crustal deformation within the Anambra Basin, Southeast Nigeria, using a combined approach of gravity derivative filters and residual geoid anomalies. First- and second-order vertical and horizontal derivatives were computed from Bouguer gravity anomalies derived from a global gravitational model using the Truncated Horizontal Plate Model. Residual geoid anomalies were derived by using Airy-Heiskanen isostatic model. These results were further processed to generate tilt angle, theta, and Tilt-Theta Angles Correlation (TTAC) maps. The derivative maps revealed multiple fault systems and structural trends (N-S, NW-SE, NE-SW) associated with rift-related tectonic activity, delineating compressional and extensional domains. High-angle faults, horsts, and grabens were discovered as the key features controlling sediment distribution and potential reservoir structures. The residual geoid and swell push force maps further made manifest zones of crustal compression and extension, corresponding to areas of sedimentary loading and tectonic uplift, particularly in the Abakaliki Anticlinorium and NE flank of the basin. While this study offers valuable structural and geodynamic insights, it is limited by its reliance on satellite-derived gravity and geoid data, which may not match the spatial resolution of terrestrial seismic surveys. This limitation suggests that the interpretations, though robust, would benefit from integration with higher-resolution seismic or borehole data. The faults and deep sedimentation (depocenters) as revealed in the derived maps demonstrate that the basin has robust structural features indicating a possible existence of hydrocarbon accumulations.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105769"},"PeriodicalIF":2.2,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680188","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 Cretaceous-Paleogene tectonic event in the Tunisian foreland basins: Insights from unconformities and basin inversion","authors":"Oussama Ben Abid ,&nbsp;Riadh Ahmadi ,&nbsp;Adnene Lafi ,&nbsp;Benen Sarsar Nouali ,&nbsp;Ali Mahroug ,&nbsp;Jamel Abdennaceur Ouali","doi":"10.1016/j.jafrearsci.2025.105770","DOIUrl":"10.1016/j.jafrearsci.2025.105770","url":null,"abstract":"<div><div>In this study, a comprehensive analysis was conducted on numerous sites within the Tunisian domains that exhibited early Atlasic inversion. The objective of this study is to evaluate and quantify this controversial compressive deformation period and conclude whether it is a local tectonic event or a regional compressional phase. Indeed, the geodynamic evolution of the Tunisian platform can be divided into major periods separated by a transitional period during the late Cretaceous. The first period was characterized by extensional movements associated with rifting phases that created several basins in a passive margin sedimentary environment. The second period was a compressive tectonic activity that occurred during the Cenozoic and resulted in major tectonic inversions.</div><div>This study examined ten distinct compressive structures, encompassing seismic line interpretation in the eastern Tunisian platforms, field outcrop maps and cross-sections, and the characterization of sedimentary hiatus. The results of the study demonstrated that during the Late Cretaceous-Eocene period, compressional structures were identified in the Golf of Hammamet, the Kairouan plains, the Golf of Gabes, and the central and meridional Atlas domains. These compressional structures have accumulated approximately 7.5 km of shortening and have exhibited a NE-SW decreasing deformation gradient from the Gulf of Hammamet to the Atlasic southern domain. Therefore, as a consequence of the cumulative shortening value, the large-scale sedimentary hiatus and the widespread deformation that was observed, it can be concluded that the Late Cretaceous-Eocene period corresponds to a confirmed compressional phase. This phase has inverted the sedimentary basins and triggered the creation of the Atlas orogen.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105770"},"PeriodicalIF":2.2,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613918","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":"Predicting Early Cretaceous deepwater turbiditic successions in the offshore Aaiun-Tarfaya Basin, southern Morocco: constraints from new data from Fuerteventura","authors":"Angel Arantegui ,&nbsp;James Lovell-Kennedy ,&nbsp;Remi Charton ,&nbsp;Tim L. Luber ,&nbsp;Luc Bulot ,&nbsp;Jonathan Redfern","doi":"10.1016/j.jafrearsci.2025.105773","DOIUrl":"10.1016/j.jafrearsci.2025.105773","url":null,"abstract":"<div><div>This paper re-examines the sedimentology and biostratigraphy of the Early Cretaceous Main Clastic Unit (Steiner et al., 1998) exposed in Fuerteventura, and provides a correlation to the proximal equivalent of the system onshore Morocco, to assess the implications for the petroleum system and potential reservoir distribution.</div><div>Lower Cretaceous coarse clastic-dominated continental to shallow-marine successions are extensively exposed in the onshore Aaiun-Tarfaya Basin, Morocco. The deep-water distal counterparts of these systems are less well-documented, and only exposed on Fuerteventura, where they have been exhumed by tectonic uplift associated with volcanism. The studied section is dated as pre-late Berriasian based on previous work and the discovery of a well-preserved ammonite as part of this study. It is made of thin bedded clastic turbidites with occasional coarser and thicker bedded intervals exposed in a succession of overturned and sub-vertical outcrops, intruded by igneous bodies, with local repetitions of the succession due to tectonic folding.</div><div>Three large-scale cycles can be identified; two coarsening-upward, interpreted to represent the progradation of lower and middle lobes of a large submarine fan and an overall fining-upward cycle with increasing contribution of calciturbidites and limestone beds. The latter is interpreted to reflect the sea-level rise during Aptian and Albian times and the associated development of carbonates on the shelf, resedimented into the deep basin as calciturbidites.</div><div>The sand content in the lower part of the three cycles can reach up to 95 %, deposited as high density turbidites. This can be correlated with the low stand wedge seen in seismic, draping the older Jurassic carbonate platform. Detailed logging and new biostratigraphy further constrain understanding of these depositional systems and their evolution, helping to reduce uncertainty in exploration for these important reservoir systems that are targets for offshore exploration.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105773"},"PeriodicalIF":2.2,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686876","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":"Exploratory evaluation of gold mineralization in Sodmein and El Haramiya areas, west Quseir, Egypt","authors":"M.M.A. Gobashy ,&nbsp;A.A. Eldougdoug ,&nbsp;A.M. Metwally ,&nbsp;M.M. Hassan","doi":"10.1016/j.jafrearsci.2025.105771","DOIUrl":"10.1016/j.jafrearsci.2025.105771","url":null,"abstract":"<div><div>The rock units exposed in the West Quseir region, encompassing the Wadi Sodmein (WS) and El Haramiya (EH) areas, are predominantly composed of metamorphic and igneous formations associated with the Pan-African Arabian–Nubian Shield. The Precambrian Nubian Shield, which constitutes the western segment of the Arabian–Nubian Shield, is well known for hosting significant mineral deposits, including iron ore, gold, copper, and rare earth elements. The primary objective of this study is to elucidate the structural framework and mineralization processes within these economically promising zones. It involves comprehensive field-based geological investigations, during which approximately 60 samples were collected for detailed petrographic analysis of the West Quseir region, specifically within the EH and WS subareas of Egypt's Eastern Desert. To achieve this, available aeromagnetic data were analysed using advanced filtering techniques, including Analytic Signal (AS), Source Parameter Imaging (SPI), Tilt Derivative, Euler Deconvolution (ED), Contact Occurrence Density (COD), and magnetic susceptibility anomaly inversion along selected land magnetic profiles. The findings reveal a complex network of dominant NW–SE and NE–SW oriented lineaments, which correspond to major shear zones and fault systems that exert significant control over mineral deposition. The filtered magnetic data delineates several anomalies that are consistent with the occurrence of gold mineralization. Additionally, rock sampling and structural measurements confirm the presence of gold-bearing quartz veins, as previously documented in earlier studies. Detailed petrographic analysis further substantiates the potential for gold mineralization within the study area, reinforcing its significance as a prospective exploration target.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"231 ","pages":"Article 105771"},"PeriodicalIF":2.2,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653570","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}