Geosystems and Geoenvironment最新文献_第5页

GIS-driven hybrid multicriteria model for flood susceptibility assessment in a coastal metropolis of Ghana 加纳沿海大都市洪水易感性评价的gis驱动混合多准则模型

Geosystems and Geoenvironment

Pub Date : 2026-02-01 Epub Date: 2025-09-22 DOI: 10.1016/j.geogeo.2025.100462

Samuel Yaw Danso

Mapping regions prone to flooding constitutes a crucial step toward developing localized solutions for flood preparedness and mitigation. This study presents a geographic information system (GIS)-driven approach that combines the decision-making trial and evaluation laboratory (DEMATEL), criteria importance through intercriteria correlation (CRITIC), and simple additive weighting (SAW) methodologies to identify flood-prone areas in the Sekondi-Takoradi Metropolis (STM), Ghana. The study's originality lies in using the hybrid DEMATEL-CRITIC-SAW model for flood susceptibility assessment, a novel integration of decision-making methods and analytical techniques not previously applied together for this purpose. This novel framework provides a comprehensive approach to analyze relationships among 11 flood-inducing variables, determine variable importance, and integrate these findings to produce a more accurate and robust flood susceptibility map. The results reveal a constructed network structure that highlights the complex relationships and dependencies among the variables. Among the assessed criteria, stream power index was identified as the most significant factor due to its high total interaction with other criteria. The flood susceptibility zones within STM are classified into five levels: very low (15%), low (27%), moderate (21%), high (22%), and very high (14%). Notably, the coastal and central sections of STM were marked as areas with moderate to very high flood susceptibility. The results, measured using the area under the curve, indicate that the proposed approach achieved a score of 0.947, demonstrating its superior performance over other existing hybrid models in the literature. The method provides actionable recommendations to authorities in STM for developing flood prevention/mitigation measures.

绘制易受洪水影响地区的地图，是朝着制定地方防洪和减灾解决方案迈出的关键一步。本研究提出了一种地理信息系统（GIS）驱动的方法，该方法结合了决策试验和评估实验室（DEMATEL）、通过标准间相关性（CRITIC）确定标准重要性（critical）和简单相加加权（SAW）方法，以确定加纳Sekondi-Takoradi大都市（STM）的洪水易发地区。该研究的独创性在于使用混合的dematel - critical - saw模型进行洪水易感性评估，这是一种新的决策方法和分析技术的整合，以前从未用于此目的。该框架提供了一种全面的方法来分析11个洪水诱发变量之间的关系，确定变量的重要性，并将这些发现整合起来，以产生更准确、更可靠的洪水易感性图。结果揭示了一个构建的网络结构，突出了变量之间的复杂关系和依赖关系。在评价标准中，水流功率指数因其与其他标准的高度相互作用而被确定为最重要的因素。将STM内的洪水易感性区划分为5个级别：极低（15%）、低（27%）、中（21%）、高（22%）和极高（14%）。值得注意的是，STM的沿海和中部地区被标记为中等至非常高的洪水易感性地区。使用曲线下面积测量的结果表明，该方法的得分为0.947，表明其优于文献中其他混合模型的性能。该方法为STM当局制定防洪/减灾措施提供了可行的建议。

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引用次数: 0

Geoelectric and hydro-geochemical assessments of waterlogging and drainage for soil and agronomic groundwater evaluation at Akwa Ibom State University: Field and laboratory data mining approaches 阿夸伊博姆州立大学土壤涝渍和排水的地电和水文地球化学评价和农业地下水评价：实地和实验室数据挖掘方法

Geosystems and Geoenvironment

Pub Date : 2026-02-01 Epub Date: 2025-10-10 DOI: 10.1016/j.geogeo.2025.100464

Nyakno J. George , Nsikak E. Bassey

Akwa Ibom State University (AKSU) in southeastern Nigeria faces recurrent waterlogging, poor drainage, and declining groundwater quality due to shallow water tables, low-permeability soils, intense rainfall, and unregulated land development. These issues have caused environmental degradation, hindered agriculture, and disrupted infrastructure. This study aims to evaluate the spatiotemporal hydrogeological and hydrochemical conditions of the AKSU campus to inform sustainable groundwater and drainage management. A combination of geophysical methods—vertical electrical sounding (VES) and electrical resistivity tomography (ERT)—was employed alongside hydrochemical analyses, data mining (Pareto and AHP), and irrigation suitability assessments. Field investigations involved 25 VES points and 2D ERT surveys, processed using WINRESIST and RES2DINV. Results identified 3–4 geoelectric layers, including productive sandy aquifers, with transmissivity values ranging from 1195.3 to 6611.6 m²/day and high correlations (R² > 0.9) between bulk aquifer resistivity and hydrodynamic parameters. Laboratory analyses showed that most groundwater samples met WHO standards, though localized exceedances of Fe, Pb, Cu, Mn, Ni, and fluoride were observed. Irrigation indices revealed that high sodium levels limit long-term agricultural suitability. Pareto and AHP analyses highlighted drainage density, rainfall, and topography as key contributors to waterlogging. The study concludes with recommendations for subsurface drainage systems, improved land use planning, and targeted water quality monitoring to support long-term environmental and agricultural resilience.

位于尼日利亚东南部的阿克瓦伊博姆州立大学（AKSU）面临着反复发生的内涝、排水不良以及由于地下水位浅、土壤渗透性低、强降雨和不受管制的土地开发而导致的地下水质量下降的问题。这些问题造成了环境退化，阻碍了农业发展，破坏了基础设施。本研究旨在评价阿克苏大学校园的时空水文地质和水化学条件，为地下水和排水的可持续管理提供依据。地球物理方法——垂直电测深（VES）和电阻率层析成像（ERT）——与水化学分析、数据挖掘（Pareto和AHP）以及灌溉适宜性评估相结合。现场调查包括25个VES点和2D ERT调查，使用WINRESIST和RES2DINV进行处理。结果发现3-4个地电层，包括生产砂质含水层，透过率值在1195.3 ~ 6611.6 m²/d之间，含水层整体电阻率与水动力参数之间具有较高的相关性（R²> 0.9）。实验室分析表明，大多数地下水样本符合世卫组织标准，尽管观察到局部铁、铅、铜、锰、镍和氟化物超标。灌溉指标显示，高钠水平限制了长期农业适宜性。帕累托和AHP分析强调了排水密度、降雨量和地形是内涝的主要因素。该研究最后提出了地下排水系统、改善土地利用规划和有针对性的水质监测的建议，以支持长期的环境和农业恢复能力。

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引用次数: 0

The supergiant Witwatersrand Goldfield: A result of anhydrous mantle degassing on Earth’s earliest supercontinent 威特沃特斯兰德金矿：地球上最早的超大陆上无水地幔脱气的结果

Geosystems and Geoenvironment

Pub Date : 2026-02-01 Epub Date: 2025-09-09 DOI: 10.1016/j.geogeo.2025.100456

Liang Zhang , David I. Groves , John L. Walshe

The origin of the supergiant high grade Witwatersrand gold deposits has attracted debate for several decades with modified gold placer models contrasting with orogenic gold crustal metamorphic models. Neither explains the anomalous quantities of gold, pyrobitumen, and ‘carbon leaders’ in the Basin during the otherwise gold- and carbon-poor Mesoarchean. The Witwatersrand, part of a trilogy with the Bushveld Complex PGE-Cr-Fe-Ti-V and Kaapvaal diamond fields as the largest deposits globally, is unique, requiring consideration of a tectonic-scale non-conventional model to explain it.

Host to the Witwatersrand Basin, the Kaapvaal Craton represents a continental block within the first supercontinent Ur. Iron-Ni alloy inclusions and terrestrial-like C isotopes in CLIPPIR diamonds within the Craton provide evidence for the addition of metals, including those that later resided in cumulate slurries in the giant Bushveld Complex, to the mantle during Archean core-mantle-crust overturns. Mesoarchean mantle degassing is considered the most likely key process for transport of gold by anhydrous fluids as indicated by CH₄ and H₂ inclusions in CLIPPIR diamonds. The lithosphere-scale Colesberg suture on the western margin of the Witwatersrand Basin, the entry for sedimentary fans during deposition of the Central Rand gold reefs and carbon leaders, represents reactivation of a subduction zone during breakup of Ur at ca. 3.0–2.9 Ga. It is proposed that this suture, recognized as a break in lithosphere profiles, acted as the conduit for CH₄ and H₂ fluids carrying Au in metal hydrides to the mid-upper mantle where CH₄ and H₂ dissociated to form hydrocarbons which extracted additional Au from mantle sulfides. The gold and hydrocarbons were then exhaled on to the western hinterland of the Witwatersrand Basin to provide the anomalous quantity of Au and C required to explain both the Witwatersrand endowment and why such a unique conjunction of factors has never occurred again in Earth history, although most subsequent primary gold-rich deposits are also now considered to have had a mantle connection.

摘要威特沃特斯兰德超巨型高品位金矿床的成因争论了几十年，修正的金砂矿模型与造山带金地壳变质模型进行了对比。两者都不能解释中太古宙盆地中金、焦沥青和“碳先导物”的异常数量。威特沃特斯兰德（Witwatersrand）与布什维尔德（Bushveld）复杂的PGE-Cr-Fe-Ti-V和Kaapvaal钻石矿是全球最大的矿床，是三部曲的一部分，它是独一无二的，需要考虑构造尺度的非常规模型来解释它。Kaapvaal克拉通是威特沃特斯兰德盆地的所在地，代表了乌尔第一超大陆内的一个大陆块。克拉通内CLIPPIR钻石中的铁镍合金包裹体和类陆相C同位素为太古宙核-幔-壳翻覆期间地幔中添加金属提供了证据，包括后来在巨大的布什维尔德杂岩中沉积的金属。中太古代地幔脱气被认为是无水流体输运金最可能的关键过程，CLIPPIR钻石中的CH₄和H₂包裹体表明了这一点。Witwatersrand盆地西缘岩石圈尺度的Colesberg缝合线是中央兰德金礁和碳先导沉积时期沉积扇的入口，代表了约3.0 ~ 2.9 Ga乌尔断裂期间俯冲带的重新激活。这条断裂带是岩石圈剖面上的断裂，是携带金属氢化物中的金的CH₄和H₂流体进入中上地幔的通道，在那里CH₄和H₂解离形成碳氢化合物，从地幔硫化物中提取额外的金。然后，金和碳氢化合物被呼到威特沃特斯兰德盆地的西部腹地，提供了异常数量的金和碳，这就解释了威特沃特斯兰德的禀性，以及为什么这种独特的因素结合在地球历史上再也没有发生过，尽管大多数后来的原生富金矿现在也被认为与地幔有联系。

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引用次数: 0

Contribution of the geoelectric method to the identification of geological formations in the Ngaoundal locality (Adamawa, Cameroon) 地电方法在Ngaoundal地区（喀麦隆Adamawa）地质构造识别中的贡献

Geosystems and Geoenvironment

Pub Date : 2026-02-01 Epub Date: 2025-10-25 DOI: 10.1016/j.geogeo.2025.100468

Abdoul Aboubakar , Bertille Ilalie Manefouet Kentsa , Grace Nissia Rodo , Oussena Bébé Nzie , Stella Nome May , Clotaire José Pako Perabi , Merlot Tongnang Kenzo , Thomas Tatietse Tamo

This study highlights the contribution of geo-electricity to the characterization of geological formations in the Ngaoundal area. Electrical mapping using the Schlumberger device was carried out over 29.9 km², with fifty-one vertical electrical soundings (VES) conducted at 700 m intervals across a zone entirely covered by soils developed on a granitic bedrock. Apparent resistivity maps, for depths ranging from AB/2 = 1.5 to 100 m, reveal low, medium, and high resistivity ranges. Ten main types of VES curves (Q, HK, KH, H, KQ, QH, HKH, K, KQH, and QHK) were identified, classified according to depth and resistivity. Integrated analysis of resistivity maps and VES curves shows lateritic soils dominating the surface, sandy-clay soils at intermediate depth, and fractured or sound bedrock at greater depth. Four pseudo-resistivity sections highlight weak (ρ < 350 Ω·m), medium (350 ≤ ρ ≤ 1800 Ω·m), and strong (ρ ≥ 1800 Ω·m) anomalies, corresponding respectively to loose weathered formations (weathered granite, gravelly soils), fractured granites, and sound granites forming the bedrock. The lateritic layer thickness map identifies three classes: low (1.33–2.58 m), medium (2.59–2.84 m), and high (2.85–8.94 m). Comparison with existing water borehole data confirms the consistency of geophysical models. This complementarity between geophysical methods and direct borehole observations reinforces the reliability of the approach and provides a robust framework for geological and hydrogeological interpretation of the subsurface in the Ngaoundal region.

这项研究强调了地电对Ngaoundal地区地质构造特征的贡献。使用斯伦贝谢的设备进行了29.9平方公里的电测绘，在一个完全被花岗岩基岩上发育的土壤覆盖的区域，以700米的间隔进行了51次垂直电测深（VES）。在AB/2 = 1.5 ~ 100 m的深度范围内，视电阻率图显示了低、中、高电阻率范围。根据测深和电阻率划分了10种主要的测深曲线类型（Q、HK、KH、H、KQ、QH、HKH、K、KQH和QHK）。电阻率图和电测深曲线综合分析表明，地表以红土土为主，中深为砂粘土土，深部为裂隙或健全基岩。4条伪电阻率剖面显示弱异常（ρ < 350 Ω·m）、中异常（350≤ρ≤1800 Ω·m）和强异常（ρ≥1800 Ω·m），分别对应于松散风化层（风化花岗岩、砾质土）、裂隙花岗岩和形成基岩的岩体。红土层厚度图划分为低（1.33 ~ 2.58 m）、中（2.59 ~ 2.84 m）、高（2.85 ~ 8.94 m） 3个等级。与现有钻孔资料对比，证实了地球物理模型的一致性。地球物理方法和直接钻孔观测之间的这种互补性加强了该方法的可靠性，并为Ngaoundal地区地下地质和水文地质解释提供了一个强大的框架。

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引用次数: 0

Stage of the vein series formation processes of the Burpala massif (North Baikal), according to chemical microprobe Th-U-Pb dating of monazites 北贝加尔湖Burpala地块脉系形成过程的阶段——单氮石化学探针Th-U-Pb测年

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2024-12-05 DOI: 10.1016/j.geogeo.2024.100345

Irina Sotnikova , Anna Spivak , Alla Viryus , Michael Kuzmin , Egor Zakharchenko , Tatiana Kolotilina , Natalia Alymova

The typomorphic features and ages of monazites from two zones of ore-bearing pegmatites of the Burpala massif (Western and Britolite) were studied. This made it possible to clarify the stages of formation of the vein phase of the intrusive rocks. Information on the relationship of monazites with rock-forming and ore minerals was also obtained. Using the CHIME method, the isochronous Th-U-Pb age of monazites from rare-metal pegmatites was calculated: 287 ± 54 Ma (Western zone) and 273 ± 69 Ma (Britholite zone). The obtained age values for the rare-metal pegmatites of the Burpala massif are in good agreement with the available geological and geochronological information and indicate the existence of several stages of their formation, which allows us to supplement the magmatism scheme of the vein complex (mariupolites → foyaites → rare-metal pegmatites of the Western zone → rare-metal pegmatites of the Britholite zone → apatite-fluorite rocks → carbonatites→ alaskites and alkaline granites). The obtained age for monazites from two zones of pegmatites is close by time of formation to the pulaskites of the main phase and rare-metal pegmatites of the North-Western zone of the Burpala massif and belongs to the general Late Paleozoic stage of intraplate magmatism in the northern framing of the Angara-Vitim batholith.

研究了布尔帕拉地块2个含矿伟晶岩带（西伟晶岩带和英立岩带）单氮石的标型特征和年龄。这使得澄清侵入岩脉相的形成阶段成为可能。还获得了有关单独居石与造岩和矿石矿物关系的资料。采用CHIME方法计算了稀土伟晶岩中独居石的Th-U-Pb等时年龄：287±54 Ma（西部带）和273±69 Ma（不列颠岩带）。得到的布尔帕拉地块稀有金属伟晶岩年龄值与已有的地质、年代学资料吻合较好，表明其存在多个形成阶段，补充了脉状杂岩的岩浆作用方案（麻乌长岩→富雅岩→西带稀有金属伟晶岩→英透岩带稀有金属伟晶岩→磷灰石-荧光岩→碳酸盐岩→阿拉斯岩和碱性花岗岩）。两个伟晶岩带的独居石年龄与布尔帕拉地块西北带的主相和稀有金属伟晶岩的形成时间接近，属于安加拉-维提姆基北架晚古生代板内岩浆活动的一般阶段。

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引用次数: 0

Assessment of the potential for using PET waste as geomaterials in soil micro-reinforcement PET废弃物作为土壤微加固材料的潜力评价

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2025-07-21 DOI: 10.1016/j.geogeo.2025.100438

Carlos J.P. Graça , Luís M. Ferreira-Gomes , Luis Andrade Pais , Antonio Albuquerque , Maria Vitoria Morais , André Studart , Leonardo Marchiori

The use of synthetic fibers to enhance soil properties is a growing area of research. This study investigates the incorporation of granulated polyethylene terephthalate (PET) waste – derived from crushed plastic soda bottles – into dune sand at 3 % and 5 % ratios to develop a novel composite material and promote PET fiber reuse as a sustainable solution. By valorizing PET waste, this approach reduces plastic pollution and mitigates the demand for natural resource extraction. Physical and mechanical characterization tests, including specific gravity, particle size distribution, normal proctor compaction, direct shear (DS), consolidated isotropic drained (CID) triaxial, and oedometric tests, were conducted on the dune sand, soil-PET mixtures, and pure PET residue. Results demonstrate that the addition of PET significantly influences the friction angle of the composite material, as evidenced by DS and triaxial CID tests. Specifically, the soil-PET mixtures exhibited enhanced shear strength compared to pure sand, while introducing 5 % of PET, the internal friction angle increased up to 12 % and 22 %, according to DS and CID triaxial tests, respectively, maintaining cohesionless behavior. These improvements are attributed to the reinforcing effect and interlocking behavior of PET particles within the sand matrix. The results indicate that PET addition enhances the shear strength and stability of sandy soils, supporting its use in earthworks. This study highlights the dual environmental and mechanical advantage of PET micro-reinforcement, providing a feasible route for plastic waste reuse in geotechnical engineering.

利用合成纤维增强土壤特性是一个日益发展的研究领域。本研究研究了将颗粒状聚对苯二甲酸乙二醇酯（PET）废料（来自破碎的塑料汽水瓶）以3%和5%的比例掺入沙丘沙中，以开发一种新型复合材料，并促进PET纤维的再利用，作为一种可持续的解决方案。通过使PET废物增值，这种方法减少了塑料污染，减轻了对自然资源开采的需求。对沙丘砂、土壤-PET混合物和纯PET残渣进行了物理力学表征试验，包括比重、粒径分布、正常普罗克特压实、直剪（DS）、固结各向同性排水（CID）三轴和径测试验。结果表明，PET的加入对复合材料的摩擦角有明显的影响，这是DS和三轴CID试验的结果。具体来说，与纯砂相比，土-PET混合物的抗剪强度得到了提高，根据DS和CID三轴试验，当引入5%的PET时，内摩擦角分别增加了12%和22%，保持了无粘结性。这些改进是由于PET颗粒在砂基体中的增强作用和联锁行为。结果表明，PET的加入提高了砂土的抗剪强度和稳定性，支持其在土方工程中的应用。本研究突出了PET微增强材料的环境和力学双重优势，为塑料废弃物在岩土工程中的再利用提供了一条可行的途径。

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引用次数: 0

Stability analysis of geotextile-reinforced unsaturated slope under drawdown conditions 土工布加筋非饱和边坡拉深稳定性分析

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2025-06-18 DOI: 10.1016/j.geogeo.2025.100423

Chikezie Chimere Onyekwena , Huabei Liu

Global warming has intensified erratic climatic events, such as increased rainfall, flooding, and rapid drawdown, often triggering slope failures. This study investigates the influence of primary and secondary geotextile reinforcements on the stability of unsaturated soil slopes under rapid and transient drawdown conditions. Seepage forces were analyzed using the effective stress B-bar method and finite element method (FEM), while slope stability was assessed using the limit equilibrium method (LEM) integrated with the unsaturated soil mechanics concepts. Results revealed that the combined use of the primary and secondary geotextile reinforcements significantly improves slope stability by mitigating shear stresses near the slope face, reducing shallow failure surfaces, and ensuring global stability. Drainage-enabled geotextiles were particularly effective, facilitating rapid dissipation of pore pressure, lowering the phreatic surface, and achieving a higher factor of safety (1.790) compared to non-drainage geotextiles (1.439). These findings highlight the dual role of geotextiles in providing reinforcement and drainage, confirming their potential as a sustainable solution for mitigating slope failures during rapid drawdown in the face of climate uncertainty.

全球变暖加剧了不稳定的气候事件，如降雨增加、洪水和快速下降，经常引发边坡破坏。研究了一次和二次土工布加筋对非饱和土质边坡在快速和瞬态沉降条件下稳定性的影响。采用有效应力b杆法和有限元法分析渗流力，结合非饱和土力学概念，采用极限平衡法评价边坡稳定性。结果表明，一次和二次土工布加筋的联合使用通过降低坡面附近的剪应力，减少浅层破坏面，确保整体稳定性，显著提高了边坡的稳定性。具有排水功能的土工布尤其有效，有助于快速消散孔隙压力，降低表层，与非排水土工布（1.439）相比，安全系数（1.790）更高。这些发现强调了土工布在提供加固和排水方面的双重作用，证实了它们在面对气候不确定性的快速下降期间作为减轻边坡破坏的可持续解决方案的潜力。

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引用次数: 0

Aeromagnetic delineation of iron ore deposits in a complex geological terrain aided by fuzzy logic 基于模糊逻辑的复杂地质地形下铁矿床航磁圈定

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2025-06-27 DOI: 10.1016/j.geogeo.2025.100410

Fahad Abubakar, Felix Bamidele Fatoye, Momohjimoh Abdulsalami, Abdullateef Aliyu

The discovery of iron ore deposits is crucial for Nigeria’s economic diversification. However, the Nigerian Bida Basin’s complex geology, extensive overburden, disputed stratigraphic boundaries and limited surface exposure hinder traditional geological and geophysical exploration methods. This study employs high-resolution aeromagnetic data covering 20,984.48 m² to delineate subsurface geological features and identify potential mineralized zones. Known ore deposits were used for validation. Signal enhancement filters, including the analytic signal (ANS), total horizontal derivative (THD), and Euler deconvolution, were applied to aid data interpretation. Depth estimates for mineralization sources range from 83.06 to 248.53 m (ANS) and 129 to 600 m (Euler). The THD highlights magnetic edge sources, with gradient amplitudes of 0.00008–0.00046 nT/m, covering 4621.42 m² (22%). The ANS refines the geometric configuration of these zones, identifying high-amplitude regions (0.07–0.16 nT/m) across 2989.34 m² (14%). These results strongly align with existing mining sites. Fuzzy membership and fuzzy overlay spatial analysis integrated the geophysical results, identifying 2667.39 m² (12.7%) as highly suitable for future metallic ore exploration. Validation using four known iron ore mining sites confirmed model accuracy, with all sites located within predicted high-potential zones. The predicted high mineralization potential zones are focus areas for further exploration and development. While the findings demonstrate the effectiveness of integrated geophysical enhancements in complex terrains, future exploration should incorporate ground-truth validation and economic feasibility assessments to refine exploration accuracy and ensure resource viability.

铁矿石储量的发现对尼日利亚的经济多样化至关重要。然而，尼日利亚Bida盆地复杂的地质、广泛的覆盖层、有争议的地层边界和有限的地表暴露，阻碍了传统的地质和地球物理勘探方法。利用20984.48 m²的高分辨率航磁数据，圈定地下地质特征，识别潜在矿化带。已知的矿床被用于验证。信号增强滤波器，包括分析信号（ANS）、总水平导数（THD）和欧拉反卷积，用于辅助数据解释。成矿源深度估计范围为83.06 ~ 248.53 m （ANS）和129 ~ 600 m （Euler）。THD突出磁边源，梯度幅值为0.00008 ~ 0.00046 nT/m，覆盖面积为4621.42 m²（22%）。ANS细化了这些区域的几何结构，确定了2989.34 m²（14%）的高振幅区域（0.07-0.16 nT/m）。这些结果与现有的采矿地点非常吻合。模糊隶属度和模糊叠加空间分析综合了物探结果，确定2667.39 m²（12.7%）为未来高度适合找矿的区域。使用四个已知的铁矿石开采地点进行验证，证实了模型的准确性，所有地点都位于预测的高潜力区域内。预测的高成矿潜力带是今后勘探开发的重点区域。虽然研究结果证明了综合地球物理增强在复杂地形中的有效性，但未来的勘探应结合地面真实性验证和经济可行性评估，以提高勘探精度并确保资源可行性。

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引用次数: 0

First evidence of Campanian-Maastrichtian shallow marine deposits from eastern Atlantic margin (Doualasub-basin, Cameroon): Palynological and sedimentological approaches 东大西洋边缘（喀麦隆doualasub盆地）坎帕尼亚-马斯特里希浅海沉积的首个证据：孢粉学和沉积学方法

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2025-06-12 DOI: 10.1016/j.geogeo.2025.100421

Milan Stafford Tchouatcha , Cecile Olive Mbesse , Magdy Salah Mahmoud , Amr Said Deaf , Jeannette Ngo Elogan Ntem , Miran Mostafa Khalaf

Integration of facies analysis with organic microfossils (mainly dinoflagellate cysts) provides insights into the paleoenvironmental reconstruction of the onshore part of the Douala sub-basin of Cameroon. Nine lithofacies were identified, grouped in three main facies agglomerate/conglomerates, sands/sandstones and clay facies were identified. These facies reflect periodic proximal to distal sediment inputs, under changing water level, most likely controlled by climate and tectonics. The recovered dinoflagellate cysts were essentially composed of Cerodinium granulostriatum, Glaphyrocysta microfenestrata, Lejeunecysta sp. and Senegalinium laevigatum, along with Longapertites marginatus, Spinizonocolpites echinatus and Spinizonocolpites baculatus as significant terrestrial pollen. The dinoflagellate cysts were indicative of a shallow marine environment, affected by freshwater influx, under fluctuating dysoxic-anoxic, suboxic-anoxic and oxic states. These paleoenvironmental characteristics are consistent with the Upper Cretaceous sedimentary cycle of the Douala sub-basin, which terminated during the Maastrichtian, with a rapid and differential marine regression. The recovered organic-walled palynomorphs were a powerful biostratigraphic tool in the correlation of Campanian-Maastrichtian in the area and surroundings.

将相分析与有机微化石（主要是鞭毛藻囊）相结合，为喀麦隆Douala亚盆地陆上古环境重建提供了新的视角。确定了9个岩相，分为3个主要岩相：砾岩相、砂砂岩相和粘土相。这些相反映了周期性的近端到远端沉积物输入，在不断变化的水位下，很可能受气候和构造的控制。发现的鞭毛孢囊主要由Cerodinium granulostriatum、Glaphyrocysta microfenestrata、Lejeunecysta sp.和Senegalinium laevigatum组成，并以Longapertites marginatus、Spinizonocolpites echinatus和Spinizonocolpites baculatus为重要的陆生花粉。鞭毛藻囊表明浅海环境受到淡水流入的影响，处于缺氧、缺氧和缺氧状态的波动状态。这些古环境特征与杜阿拉次盆地的上白垩世沉积旋回相一致，该旋回终止于马斯特里赫特时期，经历了一次快速的海相差异退变。所发现的有机壁型岩是该区与周围坎帕尼亚-马斯特里赫特对比的有力生物地层工具。

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引用次数: 0

Aquifer characterization and protective capacity evaluation using geoelectrical measurements in parts of Vindhyan Supergroup, Uttar Pradesh, India 在印度北方邦Vindhyan Supergroup部分地区，利用地电测量进行含水层表征和保护能力评价

Geosystems and Geoenvironment

Pub Date : 2025-11-01 Epub Date: 2025-06-27 DOI: 10.1016/j.geogeo.2025.100412

Anamika Pandey, Birendra Pratap

Aquifer parameters are crucial for effectively managing groundwater resources. A geoelectrical survey was conducted in parts of Mirzapur District, Uttar Pradesh, India, involving twenty-four vertical electrical soundings (VES) to characterize the aquifers and evaluate contamination levels. The Dar-Zarrouk parameters, such as longitudinal unit conductance, total transverse unit resistance, anisotropy and, aquifer parameters, were determined to characterize the aquifers and estimate their protective capacity. Transmissivity (T) values ranged from 65.32 to 49,310.05 m²/day, with an average of 24,687.69 m²/day. The study indicated a high groundwater potential in areas with overburden thickness exceeding 13 m and a reflection coefficient below 0.8. In regions with overburden thickness greater than 13 m and a reflection coefficient of 0.8 or higher, a medium groundwater potential was observed. The groundwater protective capacity assessment revealed that most locations have moderate to good protection levels. This study aids in identifying aquifer vulnerability and guiding future groundwater resource development.

含水层参数对于有效管理地下水资源至关重要。在印度北方邦Mirzapur地区的部分地区进行了地电调查，包括24次垂直电测深（VES），以确定含水层的特征并评估污染水平。利用Dar-Zarrouk参数，如纵向单位电导、总横向单位电阻、各向异性和含水层参数，确定了含水层的特征并估计了其保护能力。透过率(T)值为65.32 ~ 49310.05 m2/day，平均为24687.69 m2/day。研究表明，覆盖层厚度大于13 m、反射系数小于0.8的地区地下水潜力较大。在覆盖层厚度大于13 m、反射系数大于0.8的区域，地下水潜力为中等。地下水保护能力评价结果显示，大部分地区地下水保护水平为中等至良好。该研究有助于识别含水层脆弱性，指导未来地下水资源开发。

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