Journal of African Earth Sciences最新文献

{"title":"Corrigendum to “The role of structural legacy in the compartmentalization of the Témara aquifer, Morocco: Insight from electrical resistivity tomography and field geological data” [J. Afr. Earth Sci. 234 (2026) 105935]","authors":"Abdessamia El Alaoui , Nawal Bouya , Bennacer Moussaid , Said Ou Moua , Lahssen Baidder , Ahmed Fadili , Imane Haidara , Mohammed Slimani","doi":"10.1016/j.jafrearsci.2025.105947","DOIUrl":"10.1016/j.jafrearsci.2025.105947","url":null,"abstract":"","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105947"},"PeriodicalIF":2.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921769","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":"Mineralogical and geochemical characterization of the Wigu Hill Carbonatite dikes, Kisaki area, eastern Tanzania: Implications for rare earth elements mineralization","authors":"Almachius Tryphone Mutasingwa ,&nbsp;Akira Imai ,&nbsp;Kotaro Yonezu ,&nbsp;Akane Ito ,&nbsp;Saefudin Juhri","doi":"10.1016/j.jafrearsci.2025.105984","DOIUrl":"10.1016/j.jafrearsci.2025.105984","url":null,"abstract":"<div><div>The Wigu Hill Carbonatite is a rare-earth element (REE) deposit characterized by NW-SE and NE-SW dikes. This study combines field observations, petrography, X-ray diffractometry (XRD), X-ray fluorescence Spectroscopy (XRF), and laser ablation ICP-MS in order to understand the formation processes of the carbonatite dikes and the associated REE mineralization. The study outlines three stages in Wigu Hill Carbonatite formation: (1) the magmatic stage that includes magnetite-dolomite (Mag-Dol), apatite-dolomite (Ap-Dol), and the brecciated apatite-dolomite (brecciated Ap-Dol) carbonatites; (2) the transitional (brine-melt) stage, which includes synchysite-bastnäsite-dolomite (Syn-Bsn-Dol) and monazite-dolomite 1 (Mnz-Dol_1) carbonatites, which form by replacing the hexagonal precursor phases, and (3) the carbo-hydrothermal stage, which includes monazite-dolomite carbonatite 2 (Mnz-Dol_2) without hexagonal precursor phases. Geochemical data show that Mag-Dol has low concentrations of total light rare earth elements (∑LREE) (&lt;0.05 wt%) and total REE oxides (TREE₂O₃) (&lt;0.1 wt%). In contrast, Ap-Dol has higher contents with ∑LREE at 0.3 wt% and TREE₂O₃ at 0.5 wt%. The brecciated Ap-Dol contains ∑LREE at 1.1 wt% and TREE₂O₃ at 1.6 wt%. The Syn-Bsn-Dol contains ∑LREE at 8.9 wt% and TREE₂O₃ at 12.3 wt%. Similarly, Mnz-Dol_1 contains ∑LREE at 9.1 wt% and TREE₂O₃ at 12.6 wt%, marginally exceeding the Syn-Bsn-Dol. The Mnz-Dol_2 has ∑LREE at 6.3 wt% and TREE₂O₃ at 7.4 wt%. The REE mineralization occurred due to magmatic differentiation processes, which intensified from magmatic to transitional (brine-melt) stages, involving (1) differentiation of primary carbonatitic melts, (2) dissolution and replacement of hexagonal precursor phases, and (3) redistribution of dissolved REE into insoluble phases such as monazite.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105984"},"PeriodicalIF":2.2,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837034","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":"Mesoproterozoic orogeny in Malawi, part 1: Irumide Domain","authors":"Thomas Fullgraf ,&nbsp;Steven D. Boger ,&nbsp;Robert J. Thomas ,&nbsp;Alexis Plunder ,&nbsp;Kondwani Dombola","doi":"10.1016/j.jafrearsci.2025.105982","DOIUrl":"10.1016/j.jafrearsci.2025.105982","url":null,"abstract":"<div><div>The Mesoproterozoic Irumide belt is a paired orogen comprising two contrasting segments. The northerly, Irumide Domain, is composed of reworked Palaeoproterozoic crust and Mesoproterozoic igneous rocks. To the south, the South Irumide Domain consists of an assembly of juvenile Mesoproterozoic arc-related crustal blocks. The suture between the two domains is a sharp tectonic contact marked by a sudden change in lithologies, magmatism and isotopic signature. This paper describes the northern segment where recent geological mapping and laboratory studies allow its precise delineation in Malawi, building upon the definitions established in adjacent Zambia and Mozambique. The Irumide Domain has been subdivided into the Mzimba, Kasungu and Mchinji subdomains. Each contains high-grade paragneisses that post-date the ∼2 Ga Ubendian orogeny. Two age-sequences are recognized; an older assemblage of paragneisses and quartzites considered to be high-grade metamorphic equivalents of the Muva Supergroup in Zambia, and including the Mafingi Group in Malawi. Detrital zircon data show that the other paragneiss sequence also contains significant contributions of ∼1100 Ma source rocks currently unknown from Zambia. These younger paragneisses, together with a suite of granitoid orthogneisses dated at ∼1080 Ma, provide evidence for a short-lived Mesoproterozoic active continental margin along the southern edge of the Congo-BaNy (combined Bangweulu Block-Nyika Subdomain) Craton. The first phase of the Irumide orogeny, resulting from arc accretion of the Irumide and South Irumide Domains to the Congo Craton, is dated at 1069 ± 9 Ma by local syntectonic anatectic melting in the suture between them. This was followed by closure of the Irumide Ocean and docking of the Proto-Kalahari craton from the south at c. 1045 Ma, which represents the main Irumide tectono-metamorphic event. Voluminous, syn-collision magmatism at c. 1040 Ma resulted from melting and assimilation of Ubendian-age continental crust from the Irumide Domain mixed with mantle-derived juvenile crust of the South Irumide Domain. Structural observations show that the Irumide Domain is sandwiched between South Irumide Domain rocks at the base of the tectonic pile and Congo Craton on top. This suggests that N-directed subduction of the Irumide Ocean beneath the Irumide Domain was followed by south-directed nappe transport during the collision phase. Our revised model of the Irumide Orogeny suggests that the main crustal architecture of southern Africa was established at the end of the Mesoproterozoic and is not just the result of the Neoproterozoic Pan-African, East African orogeny as advanced by some researchers.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105982"},"PeriodicalIF":2.2,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837067","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":"GIS-based evaluation of liquefaction susceptibility in the Türkoğlu district, Kahramanmaraş: A comparative analysis using LPI and LSI","authors":"Muhammet Çınar ,&nbsp;Mitat Öztürk ,&nbsp;Ahmet Özbek ,&nbsp;Alican Kop ,&nbsp;Bahadır Çelik","doi":"10.1016/j.jafrearsci.2025.105985","DOIUrl":"10.1016/j.jafrearsci.2025.105985","url":null,"abstract":"<div><div>Soil liquefaction is a significant geotechnical hazard in earthquake-prone regions, threatening infrastructure, human safety, and economic stability. This study investigates the spatial and depth-dependent characteristics of liquefaction potential of the Türkoğlu district in Kahramanmaraş Province, a region severely impacted by the February 6, 2023, Kahramanmaraş earthquake sequence (Mw 7.8 and Mw 7.6). A total of 28 boreholes were drilled to obtain geological and geotechnical data, including soil stratigraphy, groundwater level, and Standard Penetration Test (SPT) results, with disturbed and undisturbed samples collected for laboratory analysis. Liquefaction assessments were conducted using the Simplified Procedure for an Mw 7.8 scenario and a peak ground acceleration (PGA) of 0.665 g, calculating the Liquefaction Potential Index (LPI) and Liquefaction Severity Index (LSI) for each site. LSI values ranged from 0 to 83.75, indicating risk levels from non-liquefiable to high hazard. The results were integrated into a Geographic Information System (GIS) to produce spatial liquefaction hazard maps at depths of 4 m, 8 m, and 12 m through geostatistical interpolation. The findings indicate that 76 % of the boreholes exhibit high to very high liquefaction potential according to LPI, and 60 % show moderate to high hazard according to LSI. These findings provide essential input for earthquake risk mitigation and sustainable urban planning in the Türkoğlu district.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105985"},"PeriodicalIF":2.2,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837032","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":"Impact of paleotopography on carbonate reservoir heterogeneity in the Kangan Formation: A comparative research in the central and Western Persian Gulf using the Winland method","authors":"Sogand Asadolahi Shad,&nbsp;Sepideh Davoodi,&nbsp;Vahid Tavakoli","doi":"10.1016/j.jafrearsci.2025.105977","DOIUrl":"10.1016/j.jafrearsci.2025.105977","url":null,"abstract":"<div><div>Understanding the controls on depositional and diagenetic heterogeneity is essential for predicting reservoir quality in carbonate systems, particularly in structurally complex settings. Structural features such as paleohighs strongly influence sediment distribution, diagenetic pathways, and the evolution of pore systems. However, their influence on reservoir quality has not been fully evaluated using an integrated quantitative approach. This study examines how paleohighs affect the depositional and diagenetic characteristics of the Kangan Formation carbonates using the Winland method at both micro- and macro-scales. Two wells in the Persian Gulf have been compared; one located in the central region within the S1 Field (Well A) and the other in the western region within the S2 Field (Well B). A dataset including 1159 thin sections, 989 porosity and permeability measurements, and 75 mercury injection capillary pressure analyses was employed to establish relationships between porosity, permeability, and pore-throat size distributions. In total, 10 microfacies were identified in S1 and 12 in S2, representing deposition across five carbonate sub-environments. The shallow depositional setting on the Qatar Arch paleohigh increased the influence of meteoric diagenesis and dolomitization in S1, resulting in larger pore-throat diameters. In contrast, anhydrite cementation in the S2 occluded pore-throats. Although the two fields share similar depositional conditions, differences in diagenetic intensity produced distinct reservoir characteristics. These results confirm that paleogeographic and morphological factors have had a profound effect on both depositional architecture and diagenetic modification. Application of the Winland method provided the quantitative data needed to clarify these relationships. Based on the Winland method, seven rock types were identified in S1 and eight in S2. These classifications reflect the variability in pore-throat sizes and help distinguish subtle differences in reservoir quality between the two fields. This integrated approach provides new insight into carbonate reservoir evolution and contributes to more reliable reservoir characterization for exploration and development.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105977"},"PeriodicalIF":2.2,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837066","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":"Weathering processes and the role of combined chlorite-dolomite as main neutralizing agents of acidic fluids in the Cu(-Pb-Zn-Ag) Bou Skour supergene deposit (Eastern Anti-Atlas, Morocco)","authors":"Julien Poot ,&nbsp;Remi Stanus ,&nbsp;Mohammed EL Azmi ,&nbsp;Augustin Dekoninck ,&nbsp;Lhou Maacha ,&nbsp;Gaëtan Rochez ,&nbsp;Mohammed Bouabdellah ,&nbsp;Johan Yans","doi":"10.1016/j.jafrearsci.2025.105981","DOIUrl":"10.1016/j.jafrearsci.2025.105981","url":null,"abstract":"<div><div>The Cu(-Pb-Zn-Ag) Bou Skour deposit shows the distinctive feature of having its primary mineralization (hydrothermal events) associated with veins of chlorite, dolomite and quartz in Cryogenian and Ediacaran magmatic rocks. The deposit underwent weathering, leading to the oxidation of primary sulfides, formation/neutralization of acidic fluids, and the neoformation of secondary minerals, including carbonates, silicates, and arsenates. Bou Skour deposit shows a quite unusual neutralization process of acidic fluids occurring mainly within/around the chlorite and/or dolomite veins containing primary mineralization. Chlorite, rarely considered as a dominant neutralizing agent, plays a significant role in the formation of secondary minerals in Bou Skour. The dual neutralization (chlorite and dolomite), combined with the diversity of primary assemblages and the vein-associated fractures, strongly influence secondary mineralization patterns and sequences, leading to restricted oxidized zones where different parts of weathering profile merge and overlap. Understanding these mechanisms is essential for unraveling the mineralogical evolution of the deposit and estimates its economic potential.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105981"},"PeriodicalIF":2.2,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837065","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":"Tin rich and barren tourmalines of Achemmach (El Hammam district, central Morocco): Mineralogy and physico-chemical characteristics of fluid phases","authors":"Azizi Moussaid ,&nbsp;Hafid Mezougane ,&nbsp;Ilyasse Loudaoued ,&nbsp;Mohmed Aissa ,&nbsp;Abdelali Kharis ,&nbsp;Panagiotis Voudouris ,&nbsp;Mohamed Aissa ,&nbsp;Mustapha Souhassou ,&nbsp;Muhammad Souiri ,&nbsp;Abderrahim Ardouz ,&nbsp;Hafid Ouahmad","doi":"10.1016/j.jafrearsci.2025.105973","DOIUrl":"10.1016/j.jafrearsci.2025.105973","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105973"},"PeriodicalIF":2.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787917","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":"Effect of hydrodynamic regimes on sediment transport and grain size distribution in the Oualidia Lagoon (Morocco): A numerical modeling approach","authors":"Mohammed Bouchkara ,&nbsp;Nouhaila Erraji Chahid ,&nbsp;Imane Joudar ,&nbsp;Otmane Khalfaoui ,&nbsp;Hamza El Behja ,&nbsp;Aïssa Benazzouz ,&nbsp;Bendahhou Zourarah ,&nbsp;Khalid El Khalidi","doi":"10.1016/j.jafrearsci.2025.105980","DOIUrl":"10.1016/j.jafrearsci.2025.105980","url":null,"abstract":"<div><div>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.</div><div>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.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105980"},"PeriodicalIF":2.2,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of groundwater recharge potential zones in the Haho prefecture (Togo) using AHP and MIF models within a GIS-based framework","authors":"Komlavi Eyram Agbotsou ,&nbsp;Edupuganti Naga Dhanamjaya Rao ,&nbsp;Ayyagari Venkata Surya Satya Anand ,&nbsp;Salehe Rajabu Mayange ,&nbsp;Komi Messan Dénis Amen Hor ,&nbsp;Kissao Gnandi","doi":"10.1016/j.jafrearsci.2025.105975","DOIUrl":"10.1016/j.jafrearsci.2025.105975","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105975"},"PeriodicalIF":2.2,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787787","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":"Microfacies and diagenesis impact the distribution of pore types in heterogenous carbonate reservoir rock: An example from the Bai-Hassan Oilfield, Northern Iraq","authors":"Hawar A. Zangana ,&nbsp;Fraidoon Rashid","doi":"10.1016/j.jafrearsci.2025.105976","DOIUrl":"10.1016/j.jafrearsci.2025.105976","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":"235 ","pages":"Article 105976"},"PeriodicalIF":2.2,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787918","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}