Journal of African Earth Sciences最新文献

Tin rich and barren tourmalines of Achemmach (El Hammam district, central Morocco): Mineralogy and physico-chemical characteristics of fluid phases 摩洛哥中部El Hammam地区Achemmach富锡贫瘠电气石：流体相矿物学和物理化学特征

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-15 DOI: 10.1016/j.jafrearsci.2025.105973

Azizi Moussaid , Hafid Mezougane , Ilyasse Loudaoued , Mohmed Aissa , Abdelali Kharis , Panagiotis Voudouris , Mohamed Aissa , Mustapha Souhassou , Muhammad Souiri , Abderrahim Ardouz , Hafid Ouahmad

The Achemmach region, located east of the El Hammam district in northeastern Central Morocco, is characterized by significant tin mineralization. This mineralization is hosted in E-W trending Late Visean tourmaline-bearing brecciated veins developed within sandstones and mudstones, contrasting with barren NE-SW trending tourmaline structures. Electron microprobe analyses reveal that tourmalines from the barren zones belong to metamorphic-type schorl-dravite solid solutions (up to 50 mol% dravite), whereas those from mineralized zones are granitic schorlites with significant fluorine contents (up to 0.15 apfu F). A paragenetic assemblage composed of cassiterite, stannite, chalcopyrite, arsenopyrite, pyrite, and sphalerite was identified from surface and core samples. Stannite, abundant in the mineralized veins, forms through reactions between cassiterite and Cu-rich fluids contemporaneous with chalcopyrite precipitation. Quartz, tourmaline, calcite, and fluorite constitute the principal gangue minerals. Stannite contains minor Au (up to 350 ppm) and Ag (up to 0.27 wt%), whereas cassiterite hosts up to 790 ppm Au and 600 ppm Ag. Fluid inclusion studies in quartz from tourmalinized veins indicate a progressive evolution from vapor-to supercritical aqueous fluids trapped at conditions between 500 °C/700 bar and 150 °C/100 bar. Fluids from barren veins show higher salinities than those from mineralized zones, reflecting a more metamorphic origin. The hydrothermal evolution of the Achemmach tin-bearing breccias involves two key stages: (1) trapping of vapor-rich fluids at ∼600 °C/1 kbar with salinity of ∼13.5 wt% NaCl equiv., and (2) prolonged boiling down to ∼100 °C, evidenced by increased fluid salinities.

位于摩洛哥中部东北部El Hammam地区以东的Achemmach地区具有显著的锡矿化特征。该矿化赋存于砂岩和泥岩中发育的东西向晚西世含碧玺角化脉中，与NE-SW向的秃发碧玺构造形成鲜明对比。电子探针分析表明，来自贫带的电气石属于变质型榴辉石固溶体（高达50 mol%的榴辉石），而来自矿化带的电气石则属于含氟显著（高达0.15 apfu F）的花岗质榴辉石。由锡石、锡铁矿、黄铜矿、毒砂、黄铁矿和闪锌矿组成的共生组合。锡铁矿富集于矿化脉体中，由锡石与富铜流体反应形成，同时伴有黄铜矿沉淀。石英、电气石、方解石和萤石是主要的脉石矿物。锡铁矿含有少量的Au（高达350 ppm）和Ag（高达0.27 wt%），而锡石含有高达790 ppm的Au和600 ppm的Ag。电气石化矿脉中石英的流体包裹体研究表明，在500°C/700 bar和150°C/100 bar之间的条件下，流体从蒸汽到超临界水溶液的渐进演化。贫脉流体的矿化度高于矿化带流体的矿化度，反映出其变质作用更强。Achemmach含锡角砾岩的热液演化包括两个关键阶段：(1)在~ 600°C/1 kbar条件下捕获富气流体，盐度为~ 13.5 wt% NaCl当量；(2)沸腾时间延长至~ 100°C，流体盐度增加。

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引用次数: 0

Effect of hydrodynamic regimes on sediment transport and grain size distribution in the Oualidia Lagoon (Morocco): A numerical modeling approach 水动力机制对Oualidia泻湖（摩洛哥）沉积物输运和粒度分布的影响：数值模拟方法

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-14 DOI: 10.1016/j.jafrearsci.2025.105980

Mohammed Bouchkara , Nouhaila Erraji Chahid , Imane Joudar , Otmane Khalfaoui , Hamza El Behja , Aïssa Benazzouz , Bendahhou Zourarah , Khalid El Khalidi

Coastal lagoons are dynamic coastal ecosystems that support biodiversity, regulate water quality, and provide essential ecological services. Understanding their sediment dynamics is crucial for sustainable management, particularly under growing human pressures and climate change impacts. This study investigates the hydrodynamic and sedimentary processes of the Oualidia Lagoon (Morocco) by integrating numerical hydrodynamic modelling (MIKE 21) with field observations. Tidal currents, wave action, and water levels were simulated, while Root Mean Square Velocity (RMSV) and water residence time (REST) were used to evaluate circulation efficiency and water retention. The results reveal pronounced spatial variability in hydrodynamic energy. Peak current speeds exceed 1 m s⁻¹ near the tidal inlets during spring tides, while wave analysis shows the dominance of NNW and WNW swells, which drive longshore drift and promote sediment deposition toward the sandpit and inlets. Based on RMSV and REST, three hydrodynamic zones were identified: a high-energy zone with coarse sands and limited deposition, a moderate-energy zone where erosion and deposition are balanced, and a low-energy zone favoring the accumulation of fine sediments.

This zonal classification demonstrates how hydrodynamic forcing controls sediment transport and distribution, thereby shaping the lagoon's geomorphological evolution. Importantly, this study provides a post-evaluation of management interventions such as sediment-trap dredging and dike breaching illustrating how these measures modified water circulation, reduced sediment confinement, and altered the hydrodynamic drivers of sediment transport.

沿海泻湖是动态的沿海生态系统，支持生物多样性，调节水质，并提供必要的生态服务。了解其沉积物动态对于可持续管理至关重要，特别是在人类压力和气候变化影响日益增加的情况下。本文采用数值水动力模拟（MIKE 21）和野外观测相结合的方法，研究了摩洛哥Oualidia泻湖的水动力和沉积过程。模拟潮流、波浪作用和水位，采用均方根流速（RMSV）和水停留时间（REST）评价循环效率和保水能力。结果表明，水动力能的空间变异性明显。大潮时，潮口附近水流峰值速度超过1 m s−1，波浪分析表明，NNW和WNW的浪涌主导了滨岸漂移，促使泥沙向沙坑和潮口沉积。基于RMSV和REST，确定了3个水动力带：粗砂沉积有限的高能带、侵蚀与沉积平衡的中能带和有利于细砂堆积的低能带。这种地带性分类说明了水动力强迫如何控制沉积物的运输和分布，从而塑造了泻湖的地貌演变。重要的是，本研究提供了管理干预措施的后评价，如疏浚沉积物陷阱和决堤，说明这些措施如何改变水循环，减少沉积物限制，并改变沉积物运输的水动力驱动因素。

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引用次数: 0

Assessment of groundwater recharge potential zones in the Haho prefecture (Togo) using AHP and MIF models within a GIS-based framework 基于gis的AHP和MIF模型评价多哥河湖县地下水补给潜力区

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105975

Komlavi Eyram Agbotsou , Edupuganti Naga Dhanamjaya Rao , Ayyagari Venkata Surya Satya Anand , Salehe Rajabu Mayange , Komi Messan Dénis Amen Hor , Kissao Gnandi

Sustainable groundwater resource management and development require accurate assessment grounded in contemporary technology and scientific principles. The objective of this study is to map GRPZs in the Haho Prefecture using AHP and MIF models in a geospatial framework. To achieve this, fourteen factors controlling the occurrence and flow of groundwater were selected and assigned weights. The AHP model categorized the area's GRPZs as follows: very poor (92.63 km²; 3.06 %); poor (1030.63 km²; 34.03 %); moderate (1453.38 km²; 47.98 %); good (434.88 km²; 14.36 %); and very good (17.19 km²; 0.57 %). The MIF method classified them as follows: very poor (442.25 km², 14.60 %), poor (943.19 km², 31.14 %), moderate (1057.81 km², 34.93 %), and good (585.5 km², 19.33 %). Validation through ROC curve analysis shows that the MIF model achieves a higher level of prediction accuracy (81.2 %) than the AHP approach (79.5 %). Similarly, borehole yield data show that the MIF model performs better (78.44 %) than the AHP approach (73.65 %). These results imply that the MIF model is more accurate than the AHP model in identifying GRPZs in the region. These findings will be of great assistance to decision-makers and have significant implications for ensuring sustainable development and management of groundwater in the region.

可持续的地下水资源管理和开发需要基于当代技术和科学原理的准确评估。本研究的目的是在地理空间框架中使用AHP和MIF模型绘制河湖县的grpz。为了实现这一目标，选择了14个控制地下水发生和流动的因素并赋予了权重。AHP模型将该地区的grpz划分为：极差（92.63 km2, 3.06%）；贫穷（1030.63 km2; 34.03%）；中等（1453.38 km2; 47.98%）；良好（434.88 km2; 14.36%）；非常好（17.19平方公里；0.57%）。MIF方法将其划分为：极差（442.25 km2, 14.60%）、差（943.19 km2, 31.14%）、中等（1057.81 km2, 34.93%）、良好（585.5 km2, 19.33%）。通过ROC曲线分析验证，MIF模型的预测准确率（81.2%）高于AHP方法（79.5%）。同样，井眼产量数据表明，MIF模型（78.44%）优于AHP方法（73.65%）。这些结果表明，MIF模型比AHP模型更准确地识别了该地区的grpz。这些研究结果将对决策者有很大的帮助，并对确保该区域地下水的可持续发展和管理具有重大意义。

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引用次数: 0

Microfacies and diagenesis impact the distribution of pore types in heterogenous carbonate reservoir rock: An example from the Bai-Hassan Oilfield, Northern Iraq 微相和成岩作用对非均质碳酸盐岩储层孔隙类型分布的影响——以伊拉克北部拜哈桑油田为例

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105976

Hawar A. Zangana , Fraidoon Rashid

This study examines both microfacies identification and diagenetic processes that impact the heterogeneous carbonate reservoir properties. The focus is on the Baba Formation (middle Oligocene) in the Bai-Hassan oilfield in northern Iraq to analyze microfacies characteristics and diagenetic changes to understand their influence on reservoir heterogeneity and quality. A detailed petrographic analysis of thin sections from core plugs and cutting samples identified five main microfacies types: nummulitic wackestone, rotaliida packstone, boundstone, dolomitized packstone and dolostone microfacies. The dolostone and dolomitized packstone rock types form good reservoir units. The rotaliida packstone and coral boundstone microfacies have moderate reservoir quality, while the nummulitic wackestone facies are impervious units. During the early diagenesis stage, the recrystallization process transforms part of the micritic matrix and produces microsparite. The recrystallization process increases the crystal size and enhances the primary porosity without creating visible porosity between the crystals. Dolomitization and dissolution processes are crucial in enhancing reservoir quality by increasing porosity and permeability, creating intercrystalline, moldic, and vuggy porosity. Fracture pores were also observed, which positively impact reservoir quality by enhancing fracture permeability and contributing to secondary porosity. In contrast, cementation and mechanical compaction significantly reduce early-formed primary porosity and some secondary porosity and, resulting in a negative impact on reservoir quality in certain intervals. This study provides insight into the impact of microfacies and diagenesis processes on reservoir quality, aiding in the accurate prediction of reservoir properties in heterogenous carbonate reservoir rock.

研究了影响非均质碳酸盐岩储层物性的微相识别和成岩作用。以伊拉克北部拜哈桑油田巴巴组（中渐新统）为研究对象，分析其微相特征和成岩变化，了解其对储层非均质性和储层质量的影响。对岩心桥塞和岩屑样品的薄片进行了详细的岩石学分析，确定了五种主要的微相类型：多晶岩微相、轮状岩微相、边界岩微相、白云化岩微相和白云岩微相。白云岩和白云化包岩类型是良好的储层单元。轮状岩微相和珊瑚边界岩微相储层质量中等，而多晶砾岩微相为不透水单元。在早期成岩作用阶段，再结晶作用使部分泥晶基质发生转变，形成微晶岩。再结晶过程增加了晶体尺寸并增强了原生孔隙度，而在晶体之间没有产生可见的孔隙度。白云化和溶蚀作用通过增加孔隙度和渗透率，形成晶间、模状和孔洞型孔隙，对提高储层质量至关重要。裂缝孔隙通过提高裂缝渗透率和次生孔隙度对储层质量产生积极影响。而胶结作用和机械压实作用显著降低了早期形成的原生孔隙度和部分次生孔隙度，在一定层段对储层质量产生不利影响。研究揭示了微相和成岩作用对储层质量的影响，有助于非均质碳酸盐岩储层储层物性的准确预测。

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引用次数: 0

Carbonate diagenesis and Mn-carbonate formation in the Paleoproterozoic Francevillian succession (Lastoursville sub-basin) of Gabon 加蓬古元古代Francevillian演替（Lastoursville次盆地）碳酸盐岩成岩作用与锰-碳酸盐岩形成

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105971

Kevin Xavier Nzamba , Hele-Riin Juhkama , Mathieu Moussavou , Karen Bakakas Mayika , Timmu Kreitsmann , Aivo Lepland , Anthony R. Prave , Kalle Kirsimäe

The Franceville Basin of Gabon contains one of the best-preserved records of Earth's Paleoproterozoic surface environments that began with the oxygenation of the atmosphere and its association with the largest known positive carbonate carbon isotope (δ¹³C_carb) excursion – the Lomagundi-Jatuli Event (LJE). In this study, we conducted a detailed petrographic, mineralogical, and geochemical characterization of carbonate rocks to assess the influence of authigenic and diagenetic processes affecting the primary δ¹³C_carb record preserved in core LST12 obtained in the Lastoursville sub-basin. Previous studies reported an up-section trend in δ¹³C_carb from positive values (5–9 ‰) to near-zero, and further to negative values (−5 to −17 ‰). This δ¹³C_carb shift marking the termination of the typical LJE isotopic signature coincides with changing depositional facies settings. Our new results show that this isotopic shift parallels changes in carbonate mineral composition from stoichiometric dolomite with minor early diagenetic Fe-rich dolomite overgrowths to increasingly Fe- and Mn-rich carbonates formed under sediment-buffered, closed-system diagenetic conditions. The formation of complex diagenetic Ca-Mn-Fe-rich carbonate phases in the topmost manganiferous black shales of core LST12, however, was driven by open-system diagenesis. This involved microbial remineralization of organic matter during progressive basin restriction and dynamic hydrothermal influx. The declining δ¹³C_carb trend in carbonate lithologies of LST12 core is therefore interpreted to record syn-depositional variations in the dissolved inorganic carbon pool, reflecting changing environmental conditions in the Paleoproterozoic Francevillian basin.

加蓬的Franceville盆地包含保存最完好的地球古元古代表面环境记录之一，该记录始于大气的氧化作用，并与已知最大的正碳酸盐碳同位素（δ13Ccarb）迁移- Lomagundi-Jatuli事件（LJE）有关。在本研究中，我们对该区的碳酸盐岩进行了详细的岩石学、矿物学和地球化学表征，以评估自生和成岩作用对Lastoursville次盆地LST12岩心保存的原始δ13Ccarb记录的影响。前人研究表明，δ13Ccarb具有从正值（5 ~ 9‰）到接近零，再到负值（- 5 ~ - 17‰）的上升趋势。这种δ13Ccarb位移标志着典型LJE同位素特征的终止，与沉积相环境的变化相吻合。我们的新结果表明，这种同位素转变与碳酸盐矿物组成的变化是一致的，从早期成岩阶段少量富铁白云岩过度生长的化学计量白云岩到沉积缓冲、封闭系统成岩条件下形成的日益富铁和富锰的碳酸盐。而LST12岩心上部含锰黑色页岩中富ca - mn - fe复杂成岩碳酸盐相的形成是受开放体系成岩作用驱动的。这涉及到在进行性盆地限制和动态热液流入过程中有机质的微生物再矿化作用。因此，LST12岩心碳酸盐岩岩性δ13Ccarb下降趋势被解释为记录了古元古代法兰西盆地溶解无机碳池的同沉积变化，反映了古元古代法兰西盆地环境条件的变化。

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引用次数: 0

Hydrochemistry and pollution assessment of groundwater in the Dodoma: Implications of indices and multivariate statistics Dodoma地下水的水化学和污染评价：指数和多元统计的意义

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105974

Uwezo Frank Mao , Benatus Norbert Mvile , Mahamuda Abu , Emmanuel Sulungu

Groundwater is the primary source of freshwater in arid and semi-arid regions such as Dodoma, Tanzania, where surface water is scarce. This study assessed the hydrochemical characteristics and pollution status of groundwater in the Dodoma region using water quality indices and multivariate statistical approaches. Thirty-five groundwater samples were collected from boreholes distributed across different geological and land-use settings. Laboratory analyses revealed that the groundwater is generally alkaline (pH 5.8–8.2) with total dissolved solids (TDS) ranging from 135 mg/L to 1780 mg/L and electrical conductivity (EC) between 210 μS/cm and 2740 μS/cm. The dominant cations and anions followed the order Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and Cl⁻ > SO₄²⁻ > HCO₃⁻ > NO₃⁻, respectively. Piper and base-exchange plots classified the groundwater as mainly of the Cl(SO₄)–Na and Na⁺–SO₄^2- types, indicating mineralization dominated by rock–water interaction and evaporation. The Pollution Index of Groundwater (PIG) classified 74.3 % of samples as insignificantly polluted, 17.1 % as low pollution, and 8.6 % as moderate pollution, while the Percentage Pollution Index (PPI) indicated that contamination was primarily anthropogenic. Water Quality Index (WQI) values ranged from 42 to 255, showing that 61.2 % of samples were of poor to very poor quality for drinking. Irrigation suitability assessment showed that 97.1 % of samples were suitable for salt-tolerant crops based on the permeability index and salinity hazard classification. Overall, groundwater mineralization in Dodoma is controlled by both geogenic and anthropogenic processes, emphasizing the need for regular monitoring and mitigation of human-induced contamination.

地下水是干旱和半干旱地区淡水的主要来源，如坦桑尼亚的Dodoma，那里的地表水稀缺。采用水质指标和多元统计方法，对多马地区地下水的水化学特征和污染状况进行了评价。从分布在不同地质和土地利用环境中的钻孔中收集了35个地下水样本。实验室分析表明，地下水总体呈碱性（pH值5.8 ~ 8.2），总溶解固形物（TDS）在135 ~ 1780 mg/L之间，电导率（EC）在210 ~ 2740 μS/cm之间。优势阳离子和阴离子依次为Na+ >； Ca2+ > Mg2+ >； K+和Cl−>； SO42−> HCO3−> NO3−。Piper和base-exchange样地将地下水划分为Cl(SO4) - Na型和Na+ - so42 -型，表明成矿作用以岩水相互作用和蒸发为主。地下水污染指数（PIG）将74.3%的样本划分为轻度污染，17.1%为低污染，8.6%为中度污染，而百分比污染指数（PPI）表明污染主要是人为污染。水质指数（WQI）值介于42至255之间，表明61.2%的样本水质差至极差。灌溉适宜性评价结果表明，97.1%的样品适合种植耐盐作物。总体而言，Dodoma的地下水矿化受到地质和人为过程的控制，强调需要定期监测和减轻人为污染。

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引用次数: 0

Evolution of the Suhum Basin of the Rhyacian Birimian terrane in Ghana: Insight from paraschist and orthoamphibolite 加纳里亚纪- Birimian地体Suhum盆地的演化：来自副长岩和正角闪岩的启示

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105978

Daniel Kwayisi , Susanna S. Boateng , Naa A. Agra , Solomon Anum , Raymond W. Kazapoe , Abigail E. Ayikwei , Chris Y. Anani , Daniel K. Asiedu

We present petrographical and geochemical data of paraschists and orthoamphibolite from the Suhum-Akwadum area of the Suhum Basin, Ghana, to determine their provenance, petrogenesis, and tectonic setting, and discuss the crustal evolution of the Rhyacian Birimian terrane of the West African Craton. The amphibolite exhibits trace element signatures similar to those of subalkaline basalts. Two main geochemical groups are present: (1) dominant arc-rocks with negative Nb-Ta, Ti, low Nb/Th and high La/Nb, and (2) subordinate enriched mid-ocean ridge basalts characterised by moderate to high TiO₂, positive Ta and high Nb/Th value. These compositions are interpreted as formation in a supra-subduction zone setting. The schists are geochemically classified as shales and wackes and have <60 CIA, <70 CIW, moderate to high Al₂O₃/TiO₂ and Na₂O/K₂O, low SiO₂/Al₂O₃, La/Sc, and Ti/Zr values. These geochemical signatures are consistent with low chemical weathering intensity, immature to moderately mature sediments and deposition in an active continental margin setting with sediments sourced from greenstone and granitoid-gneiss complexes of the Rhyacian Birimian terrane. Therefore, the current and previous geochemical data confirm the presence of an arc tectonic setting in the formation of the metasedimentary basins of the Birimian terrane. The overall geochemical data suggest that the greenstones and metasedimentary rocks formed during an orogenic event related to an arc environment where subduction zone components contributed to the generation of their parental magmas and sedimentation. This finding is consistent with the onset of “modern-style” subduction-related processes during the Archean-Paleoproterozoic transitional period.

本文介绍了加纳苏胡姆盆地Suhum- akwadum地区的副长岩和正角闪岩的岩石学和地球化学资料，确定了它们的物源、岩石成因和构造背景，并讨论了西非克拉通Rhyacian Birimian地体的地壳演化。角闪岩具有与亚碱性玄武岩相似的微量元素特征。主要有两个地球化学类群：(1)以负Nb-Ta、负Ti、低Nb/Th和高La/Nb为主的优势弧岩；(2)以中~高TiO2、正Ta和高Nb/Th为特征的次级富集洋中脊玄武岩。这些成分被解释为位于超俯冲带背景下的地层。片岩地球化学分类为页岩和碎屑岩，具有60 CIA和70 CIW，中高Al2O3/TiO2和Na2O/K2O，低SiO2/Al2O3、La/Sc和Ti/Zr值。这些地球化学特征与低化学风化强度、未成熟到中成熟的沉积物和沉积在活动大陆边缘环境下的沉积物相一致，沉积物来源为流序- Birimian地体的绿岩和花岗岩-片麻岩杂岩。因此，目前和以往的地球化学资料证实，在Birimian地体的变质沉积盆地形成过程中存在弧形构造环境。综合地球化学资料表明，绿岩和变质沉积岩形成于一个与弧环境有关的造山事件中，俯冲带成分促进了母岩浆和沉积的产生。这一发现与太古宙-古元古代过渡时期“现代式”俯冲作用的发生相一致。

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引用次数: 0

Basement architecture and structural styles of part of the Nigerian sector of the Chad Basin (Bornu Basin) 乍得盆地（Bornu盆地）尼日利亚部分地区基底建筑与构造样式

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-13 DOI: 10.1016/j.jafrearsci.2025.105979

Solomon Nehemiah Yusuf , Ezekiel Yusuf Yenne , Mubarak Umar Faruk

Lineament detection and depth estimation methods based on advanced aeromagnetic data were applied to the Nigerian sector of the Chad (Bornu) Basin to delineate structural framework, basement configuration and evaluate their hydrocarbon significance. Power spectral analysis was used to separate deep and shallow magnetic sources, while Euler deconvolution and finite local wavenumber techniques estimated basement depths and mapped major fault systems. Derivative-based filters such as the second vertical derivatives (SVD), analytic signal and Goussev filter enhanced the definition of intrusive and tectonic features. The interpreted structures mainly trend NE–SW, ENE–WSW, and NNE–SSW, aligning with Pan-African reactivation and Cretaceous rifting that formed the basin. The depth of the basement ranges from 1 to 5 km, while sedimentary thicknesses lie between 2.3 and 5.2 km, suggesting substantial sedimentary sequences conducive to hydrocarbons generation and accumulation. Structural lows align with depocentres related to thermal maturation zones, whereas multiple mapped faults coincide with current deep well sites (Ngamma East-1, Ngor North-1, Kanadi-1, Krumta-1, and Murshe-01). The results confirm that basement geometry and fault-controlled deformation significantly influence hydrocarbon migration pathways within the Bornu Basin.

在乍得（Bornu）盆地尼日利亚段应用基于先进航磁数据的剖面探测和深度估计方法，圈定构造格架、基底构型并评价其油气意义。功率谱分析用于分离深、浅磁源，欧拉反褶积和有限局域波数技术用于估计基底深度和绘制主要断层系统。二阶垂直导数（SVD）、解析信号和Goussev滤波等基于导数的滤波增强了对侵入和构造特征的定义。解释构造以NE-SW、ENE-WSW、NNE-SSW为主，与泛非再活动和白垩系裂陷形成盆地一致。基底深度为1 ~ 5 km，沉积厚度为2.3 ~ 5.2 km，具有丰富的生烃成藏层序。构造低与热成熟带相关的沉积中心对齐，而多个已绘制的断层与目前的深井位置（Ngamma East-1、Ngor North-1、kanadi1、Krumta-1和Murshe-01）一致。结果表明，基底几何形状和断裂控制变形对Bornu盆地油气运移路径有重要影响。

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引用次数: 0

Deciphering the Cenozoic detrital record of the External Rif Belt (Northern Morocco): insights for the evolution of the NW African Margin 外裂谷带（摩洛哥北部）新生代碎屑记录的破译：对西北非洲边缘演化的启示

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-11 DOI: 10.1016/j.jafrearsci.2025.105970

Juan Carlos Cañaveras, Manuel Martín-Martín

This study investigates the Cenozoic geodynamic, palaeogeographic, and palaeoclimatic evolution of the Moroccan NW African Margin through petrographic analysis of 18 stratigraphic sections across the Maghrebian Flysch Basin and the External Rif Zone. Detrital samples (comprising arenites and microconglomerates) are classified as quartzarenites, sublitharenites, and litharenites. These rocks are dominated by quartz and lithics, with scarce intrabasinal carbonate content. Provenance signatures reveal a polycyclic origin with the presence of low-to medium-grade metamorphic sources, likely derived from pre-Alpine orogens (African Craton, Pan-African belt, and/or Variscan mesetas), with contributions from plutonic intrusions. During the Oligo-Miocene, sections show increased quartz, particularly in distal foreland domains, reflecting tectonic uplift and enhanced recycling. Minor mafic input in the Intrarif/Mesorif suggests episodic oceanic crust or subduction-related volcanic contributions. Palaeoclimate proxies suggest moderate to high chemical weathering, with peak warming and aridity during the Paleocene-Eocene and Middle-Late Miocene intervals. Textural maturity ranges from well-sorted quartzarenites to submature arenites, supported by low content of feldspar and unstable grains content, suggesting a history of prolonged sediment transport, multicyclic recycling, and diagenetic overprinting. Comparative analysis with the South Iberian, North Tunisian, West Adriatic and Moldavidian- Scythian-Moessian Margins show inmature sediments in the internal areas, ultramature sediments close to the foreland and mixed succession of the two formers in intermediate positions. In particular, the South Iberian Margin shares quartz-lithic dominance but lacks metamorphic/plutonic clasts, whereas the West Adriatic Margin is characterized by persistent arc-derived volcanoclastics. These disparities highlight distinct geodynamic and palaeogeographic regimes across the Western Tethys during the Cenozoic. Our findings constrain orogenic recycling, sediment routing, and climatic feedbacks in the NW African Margin, providing insights for Mediterranean Alpine belts geodynamic reconstructions.

本文通过对马格里布-弗莱什盆地和外裂谷带18个地层剖面的岩石学分析，探讨了摩洛哥-西北非洲边缘地区的新生代地球动力学、古地理和古气候演化。碎屑样品（包括砂粒岩和微砾岩）分为石英砂粒岩、亚岩屑砂粒岩和岩屑砂粒岩。这些岩石以石英和岩屑为主，基底内碳酸盐含量较少。物源特征显示其为多旋回成因，存在中低变质物源，可能来源于前阿尔卑斯造山带（非洲克拉通、泛非带和/或Variscan mesetas），并有深部侵入的贡献。渐新世至中新世期间，剖面显示石英增加，特别是在远前陆域中，反映了构造隆升和再循环增强。内/中中生代的少量基性输入表明，洋壳或与俯冲有关的火山作用是幕式的。古气候指标显示，古新世—始新世和中新世中后期为中高化学风化期，气候变暖和干旱达到高峰。其结构成熟度从分选良好的石英砂质到亚成熟砂质不等，由较低的长石含量和不稳定的颗粒含量支撑，表明其具有长期的沉积物输运、多旋回再循环和成岩复印的历史。与南伊比利亚、北突尼斯、西亚得里亚海和摩尔达维-斯基泰-莫西边缘的对比分析表明，内部为不成熟沉积，靠近前陆为超成熟沉积，两者在中间位置混合演替。特别是，南伊比利亚边缘以石英岩屑为主，缺乏变质/深成碎屑，而西亚得里亚海边缘则以持续的弧源火山碎屑为特征。这些差异突出了新生代西特提斯地区独特的地球动力学和古地理制度。我们的发现限制了西北非洲边缘的造山带循环、沉积物路径和气候反馈，为地中海高寒带的地球动力学重建提供了见解。

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引用次数: 0

Climatic and tectono-geomorphological controls on karst spring dynamics: Case study of the El Menzel Causse, Middle Atlas (Morocco) 气候和构造地貌对岩溶泉动力学的控制：以摩洛哥中阿特拉斯El Menzel成因为例

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of African Earth Sciences

Pub Date : 2025-12-09 DOI: 10.1016/j.jafrearsci.2025.105972

Iliass Naouadir , Marzieh Khalili , Salih Muhammad Awadh , Samira Adil , El Hassane Chellai , Mohammed Ettaki , Abdennabi Alitane , Abdallah Elaaraj , Zaher Mundher Yaseen

Karst aquifers in semi-arid regions are vital yet exceptionally vulnerable lifelines. This study investigates how tectonic, geomorphological, and climatic factors control the dynamics of karst springs in the El Menzel Causse (Middle Atlas, Morocco). Using an integrated approach that combines field investigations, remote sensing, and quantitative hydro-climatic analysis, we identify the mechanisms driving the system's severe decline. Results indicated that the structural architecture of the major fault systems in the North Middle Atlas Fault (NMAF) and the Median Middle Atlas Fault (MMAF), governs the spatial distribution of more than 50 springs, which occur preferentially within highly permeable fault damage zones. However, the aquifer is under severe climatic stress, evidenced by a statistically significant decline in precipitation and an increased frequency of droughts. The system's response appeared dramatic: only five springs remained active in 2024, with discharge reductions exceeding 80 % compared to historical records. Anthropogenic pressures including groundwater overextraction and wastewater contamination critically amplify this crisis. In conclusion, this research presents El Menzel as a “sentinel system” whose collapse serves as a warning for other karst regions worldwide, highlighting the urgent need for science-informed, adaptive water management strategies to prevent irreversible resource depletion.

半干旱地区的喀斯特含水层是至关重要但又极其脆弱的生命线。本研究探讨了构造、地貌和气候因素如何控制El Menzel Causse （Middle Atlas，摩洛哥）喀斯特泉的动态。通过结合实地调查、遥感和定量水文气候分析的综合方法，我们确定了导致该系统严重衰退的机制。结果表明，北中阿特拉斯断层（NMAF）和中阿特拉斯断层（MMAF）主要断裂系统的构造结构控制了50多个弹簧的空间分布，这些弹簧优先出现在高渗透性断层破坏区内。然而，含水层正处于严重的气候压力之下，从统计数据来看，降水显著减少和干旱频率增加就是明证。该系统的反应非常明显：2024年只有5个弹簧保持活跃，与历史记录相比，排放量减少了80%以上。包括地下水过度开采和废水污染在内的人为压力严重加剧了这一危机。总而言之，本研究将El Menzel作为一个“哨兵系统”，其崩溃为全球其他喀斯特地区敲响了警钟，强调迫切需要科学的、适应性的水资源管理战略，以防止不可逆转的资源枯竭。

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引用次数: 0