Geosystems and Geoenvironment最新文献

{"title":"A lacustrine record of rainfall-induced variations in the pedogenic and weathering processes during the Late Holocene","authors":"Adichinalniravel S. Yamuna ,&nbsp;Anish K. Warrier ,&nbsp;Bharti Sharma ,&nbsp;Kizhur Sandeep ,&nbsp;Mamilla Venkateshwarlu ,&nbsp;Powravi Sai ,&nbsp;George S. Joju ,&nbsp;Geetha H. Aravind ,&nbsp;Abdul K. Rafaz ,&nbsp;Kakunja V. Reshma ,&nbsp;Rajveer Sharma","doi":"10.1016/j.geogeo.2025.100441","DOIUrl":"10.1016/j.geogeo.2025.100441","url":null,"abstract":"<div><div>In recent decades, extreme weather events have become more frequent across the globe. It necessitates a deeper understanding of the underlying driving mechanisms. This study reconstructs the paleoclimatic variability of southern India, particularly the coastal Karnataka, over the past two millennia using a multiproxy approach (geochronology, environmental magnetism, sedimentology, inorganic geochemical analysis, Fourier Transform Infrared Spectroscopy, Diffuse Reflectance Spectroscopy, and loss-on-ignition). The study was conducted on a 1.54-m-long lacustrine sediment core covering the past 1566 years, from 2005 to 439 cal yr BP. Four distinct climatic phases were delineated, reflecting successive stages of the Indian Summer Monsoon (ISM) strengthening in the Late Holocene. Phase 1, which spans from 2000 to 1550 cal yr BP, experienced moderately low rainfall and weak pedogenesis. In Phase 2 (1550–1230 cal yr BP), the monsoon strengthened, leading to strong precipitation, intense weathering and pedogenesis, and high lake levels. Phases 3 (1230–570 cal yr BP) and 4 (570–439 cal yr BP) experienced stronger monsoons and a burst of rainfall that strengthened catchment streams, elevated lake levels, and increased productivity and sedimentation rate. A comparative study with regional records suggests a similar trend in broad climate variability, revealing a global teleconnection. The climatic evolution of coastal Karnataka aligns with the shifts in the Intertropical Convergence Zone (ITCZ), El Niño Southern Oscillation (ENSO), and Total Solar Irradiance (TSI). Additionally, the signatures of global factors like ITCZ, ENSO, and TSI have been overprinted by the signatures of regional factors such as sea surface temperature (SST), especially during periods of active Indian Ocean Dipole (IOD).</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100441"},"PeriodicalIF":0.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GIS-driven hybrid multicriteria model for flood susceptibility assessment in a coastal metropolis of Ghana","authors":"Samuel Yaw Danso","doi":"10.1016/j.geogeo.2025.100462","DOIUrl":"10.1016/j.geogeo.2025.100462","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100462"},"PeriodicalIF":0.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"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","authors":"Nyakno J. George ,&nbsp;Nsikak E. Bassey","doi":"10.1016/j.geogeo.2025.100464","DOIUrl":"10.1016/j.geogeo.2025.100464","url":null,"abstract":"<div><div>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 &gt; 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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100464"},"PeriodicalIF":0.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The supergiant Witwatersrand Goldfield: A result of anhydrous mantle degassing on Earth’s earliest supercontinent","authors":"Liang Zhang ,&nbsp;David I. Groves ,&nbsp;John L. Walshe","doi":"10.1016/j.geogeo.2025.100456","DOIUrl":"10.1016/j.geogeo.2025.100456","url":null,"abstract":"<div><div>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.</div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100456"},"PeriodicalIF":0.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contribution of the geoelectric method to the identification of geological formations in the Ngaoundal locality (Adamawa, Cameroon)","authors":"Abdoul Aboubakar ,&nbsp;Bertille Ilalie Manefouet Kentsa ,&nbsp;Grace Nissia Rodo ,&nbsp;Oussena Bébé Nzie ,&nbsp;Stella Nome May ,&nbsp;Clotaire José Pako Perabi ,&nbsp;Merlot Tongnang Kenzo ,&nbsp;Thomas Tatietse Tamo","doi":"10.1016/j.geogeo.2025.100468","DOIUrl":"10.1016/j.geogeo.2025.100468","url":null,"abstract":"<div><div>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 (<em>ρ</em> &lt; 350 Ω·m), medium (350 ≤ <em>ρ</em> ≤ 1800 Ω·m), and strong (<em>ρ</em> ≥ 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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100468"},"PeriodicalIF":0.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145464839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stage of the vein series formation processes of the Burpala massif (North Baikal), according to chemical microprobe Th-U-Pb dating of monazites","authors":"Irina Sotnikova ,&nbsp;Anna Spivak ,&nbsp;Alla Viryus ,&nbsp;Michael Kuzmin ,&nbsp;Egor Zakharchenko ,&nbsp;Tatiana Kolotilina ,&nbsp;Natalia Alymova","doi":"10.1016/j.geogeo.2024.100345","DOIUrl":"10.1016/j.geogeo.2024.100345","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100345"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability analysis of geotextile-reinforced unsaturated slope under drawdown conditions","authors":"Chikezie Chimere Onyekwena ,&nbsp;Huabei Liu","doi":"10.1016/j.geogeo.2025.100423","DOIUrl":"10.1016/j.geogeo.2025.100423","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100423"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the potential for using PET waste as geomaterials in soil micro-reinforcement","authors":"Carlos J.P. Graça ,&nbsp;Luís M. Ferreira-Gomes ,&nbsp;Luis Andrade Pais ,&nbsp;Antonio Albuquerque ,&nbsp;Maria Vitoria Morais ,&nbsp;André Studart ,&nbsp;Leonardo Marchiori","doi":"10.1016/j.geogeo.2025.100438","DOIUrl":"10.1016/j.geogeo.2025.100438","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100438"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aeromagnetic delineation of iron ore deposits in a complex geological terrain aided by fuzzy logic","authors":"Fahad Abubakar,&nbsp;Felix Bamidele Fatoye,&nbsp;Momohjimoh Abdulsalami,&nbsp;Abdullateef Aliyu","doi":"10.1016/j.geogeo.2025.100410","DOIUrl":"10.1016/j.geogeo.2025.100410","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100410"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First evidence of Campanian-Maastrichtian shallow marine deposits from eastern Atlantic margin (Doualasub-basin, Cameroon): Palynological and sedimentological approaches","authors":"Milan Stafford Tchouatcha ,&nbsp;Cecile Olive Mbesse ,&nbsp;Magdy Salah Mahmoud ,&nbsp;Amr Said Deaf ,&nbsp;Jeannette Ngo Elogan Ntem ,&nbsp;Miran Mostafa Khalaf","doi":"10.1016/j.geogeo.2025.100421","DOIUrl":"10.1016/j.geogeo.2025.100421","url":null,"abstract":"<div><div>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 <em>Cerodinium granulostriatum, Glaphyrocysta microfenestrata, Lejeunecysta</em> sp. and <em>Senegalinium laevigatum,</em> along with <em>Longapertites marginatus, Spinizonocolpites echinatus</em> and <em>Spinizonocolpites baculatus</em> 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.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100421"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}