Geosystems and Geoenvironment最新文献

{"title":"Morphological, mineralogical and geochemical characterization of Ngaoundal soils (Adamawa-Cameroon): Implications for weathering mechanisms and trajectories in tropical zones","authors":"Abdoul Aboubakar ,&nbsp;Ilalie Bertille Kentsa Manefouet ,&nbsp;Loique Rodolph Mbounou Azefack ,&nbsp;Yannick Langollo Tchedele ,&nbsp;Dalil Adoulko ,&nbsp;Demonstel Yvan Ntomb ,&nbsp;Abakar Mahamat ,&nbsp;Jacques Wadjou Wassouo ,&nbsp;Quentin marc Anaba Fotze","doi":"10.1016/j.geogeo.2025.100450","DOIUrl":"10.1016/j.geogeo.2025.100450","url":null,"abstract":"<div><div>Ngaoundal, located in the Adamaoua region of Cameroon, has a tropical climate and is known for its characteristic soils. The aim of the present study was to evaluate the action of weathering on Ngaoundal's lateritic soils. Morpho-structural, mineralogical and geochemical analyses enabled us to carry out this study. The morphological study carried out on 15 soil samples shows a variation in colour from reddish (2.5YR 5/8) to dark brown (7.5YR 6/8), varying from reddish yellow (7.5YR 6/8), orange brown (10YR 5/6) and yellowish brown (10YR 5/4), and have clayey to sandy-clayey matrices with nodules of the order of millimetres to centimetres. X-ray diffractometry and x-ray fluorescence show the following mineral phases in Ngaoundal's lateritic soils: quartz, goethite, gibbsite, kaolinite, hematite, magnetite, anatase and boehmite. Geochemical analysis of these soils shows high average levels of SiO₂ (36.41 %), Fe₂O₃ (31.48 %) and Al₂O₃ (17.72 %), and low average levels of TiO₂ (1.02 %) and CaO (0.36 %), which characterise characteristic soils rich in ferruginous oxide and alumina oxide. The weathering indices of Ngaoundal soils (sesquioxide ratio) vary between 0.22 and 2.98 with an average of 1.09. This average value qualifies these soils as lateritic soils rich in gibbsite and kaolinite (average CIA = 96.38 %) and resulting from chemical alteration of the hydrolysis type (alloying and monosiallitisation).</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100450"},"PeriodicalIF":0.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895609","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":"Pore size characterization of Cretaceous ironstone by low-field nuclear magnetic resonance technique","authors":"A.A. Ige-Adeyeye ,&nbsp;O.B. Olatinsu ,&nbsp;V.C. Ozebo ,&nbsp;L. Esteban","doi":"10.1016/j.geogeo.2025.100449","DOIUrl":"10.1016/j.geogeo.2025.100449","url":null,"abstract":"<div><div>The microstructure of Cretaceous ironstone samples of Yewa within Eastern Dahomey Basin in Southwest Nigeria, has been investigated using low-field nuclear magnetic resonance and conventional porosity measurements. The aim was to evaluate the porosity and pore structure for heat flow consideration in blast furnace or rotary kiln. A total of eighteen iron core samples were analyzed using: X-ray fluorescence (XRF) spectroscopy to determine the percentage composition of iron content; water imbibition porosity (WIP) from dry and saturated sample weights; and low-field nuclear magnetic resonance (NMR) measurements at full water saturation for pore structure and pore size distribution. The average percentage by weight of iron content in the samples is 55 %. Porosity and water content from NMR and WIP shows high degree correlation of 79 % and 97 %, respectively with average porosities from both procedures given as 22.06 pu. and 21.96 pu., respectively. The NMR-<em>T</em>₂ distributions depict multimodal pore system with high degree of connectivity. The transverse relaxation time ranges have been classified into three regions: micropores, 0.3162–0.5012 ms, mesopores, 19.95–84.28 ms and macropores, 199.5–2117 ms, respectively. Using an established average surface relaxivity value (338 µms⁻¹) for haematite, the logarithmic mean of pore radius was estimated from the pore size distributions with values of 0.3098 µm, 33.57 µm and 733.3 µm, for micropores, mesopores and macropores, respectively. The strong pore connectivity demonstrated by the NMR-<em>T</em>₂ distribution, porosity values, and pore geometry all provide strong evidence that the iron ore samples from the study site will maximize heat and gas flow, improve reducibility and increase process efficiency in a rotary kiln or blast furnace. These findings provide valuable insights into the petrophysical characteristics of Yewa iron ores, thereby enhancing our understanding of its potential applications in the mining and ore processing industries.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100449"},"PeriodicalIF":0.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879908","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":"Identifying seawater intrusion in coastal areas using the transient electromagnetic method at Santolo Beach, Garut, West Java, Indonesia","authors":"Vitasha Adha Chaerul ,&nbsp;I Gede Putu Fadjar Soerya Djaja ,&nbsp;Prihandhanu Mukti Pratomo ,&nbsp;Supriyadi ,&nbsp;Elfitra Desifatma ,&nbsp;Anggie Susilawati ,&nbsp;Dini Andriani ,&nbsp;Harry Mahardika ,&nbsp;Eleonora Agustine ,&nbsp;Wahyu Srigutomo","doi":"10.1016/j.geogeo.2025.100440","DOIUrl":"10.1016/j.geogeo.2025.100440","url":null,"abstract":"<div><div>Seawater intrusion contaminates freshwater in coastal areas, disrupting the environment and posing health risks due to high chloride content. Monitoring and mapping the seawater-freshwater interface is essential for evaluating and mitigating the environmental damage caused by this phenomenon. A widely used geophysical technique for mapping is the transient electromagnetic (TEM) method, which detects seawater intrusion by leveraging the significant resistivity differences between saline water, freshwater, and other geological layers.</div><div>This study utilized 21 TEM sounding points at Santolo Beach, Garut, West Java, Indonesia. The data were processed through an iterative inversion procedure using a smoothness constraint scheme. Interpretation of the transient magnetic field across all sounding points revealed a resistivity structure comprising three main layers: (1) a surface layer with high resistivity (&gt;50 Ωm) extending to a depth of 15 m and thinning as it moves away from the coastline; (2) a middle layer with moderate resistivity (5–50 Ωm), ranging from 15 m to 40 m and thickening inland; and (3) a conductive layer, identified as seawater intrusion, with low resistivity (&lt;5 Ωm), situated &gt;40 m deep and deepening farther from the coastline. Additionally, water quality at several TEM sounding points was assessed using parameters such as total dissolved solids (TDS), electrical conductivity (EC), pH, and water temperature. The findings indicate that surface water in the area, obtained from wells and swamps, meets the required quality standards for potable water.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100440"},"PeriodicalIF":0.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827757","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":"Urbanization induced heat wave risk assessment of Khulna City, Bangladesh: A 30-years analysis of land surface temperature, climate trends and forecasting","authors":"Nusrat Jahan Suborna ,&nbsp;Raian Islam Evan ,&nbsp;Mostafa Jaman Rabby ,&nbsp;Maksudur Rahman ,&nbsp;Arabe Khan ,&nbsp;Md Mahmudul Hasan Rakib ,&nbsp;Rahat Khan ,&nbsp;Irteja Hasan ,&nbsp;Dhiman Kumer Roy","doi":"10.1016/j.geogeo.2025.100448","DOIUrl":"10.1016/j.geogeo.2025.100448","url":null,"abstract":"<div><div>This study examines how urbanization has influenced heatwave risk in Khulna, Bangladesh, from 1993 to 2023 by analyzing changes in land surface temperature (LST) and land use land cover (LULC) using satellite imagery and statistical methods. Over the 30‐year period, mean LST rose by 7 °C, with 23.7 % of Khulna now classified as an excessive heat zone. The Mann–Kendall (MK) test and Sen’s slope (SS) estimator confirm a significant warming trend, particularly during the warmest months. Pearson correlation (PC) analysis indicates a negative relationship between temperature and humidity, exacerbating heatwave severity. LULC results reveal that urbanized areas have expanded approximately threefold while vegetation cover has decreased by nearly 50 %. Using a seasonal-trend decomposition based on LOESS with an auto regressive integrated moving average (STL‐ARIMA) model, the study forecasts 29 additional heatwave days exceeding 36 °C over the next five years. This projection suggests a likely intensification of the urban heat island (UHI) effect driven by rapid urban growth and diminished natural spaces, heightening heat‐related hazards. The findings support the need for sustainable urban development strategies in Khulna, such as increasing green cover and improving water management to inform policy interventions aimed at mitigating rising heat risks in the city’s expanding urban environment.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100448"},"PeriodicalIF":0.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863948","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":"Geochemical and mineralogical constraints on lithium mineralization in rare-metal pegmatites of the Amareshwar region, Eastern Dharwar Craton, India","authors":"C.S. Sindhuja ,&nbsp;M. Satyanarayanan ,&nbsp;Srijita Banerjee ,&nbsp;Soumi Chatterjee","doi":"10.1016/j.geogeo.2025.100439","DOIUrl":"10.1016/j.geogeo.2025.100439","url":null,"abstract":"<div><div>Around 50 percent of global lithium resources are hosted in the rare-metal pegmatites. The present study deals with whole-rock geochemistry as well as zinnwaldite mineral chemistry of rare-metal pegmatites from Amareshwar, Gurugunta schist belt, Eastern Dharwar Craton to understand the source of lithium bearing ore fluids in these pegmatites and to evaluate their mineralization potential. Detailed petrography and mineral chemistry of Amareshwar pegmatites indicate that lithium is hosted in both spodumene and zinnwaldite. The zinnwaldite mineral chemistry elucidates the incorporation of lithium in mica crystal lattice along the vector Al₂(R²⁺)_–3. The whole rock geochemical signatures suggest that these pegmatites are alkaline to calc-alkaline in nature, peraluminous and emplaced in S-type and syn-collisional tectonic setting. The chondrite normalized REE patterns are characterized by prominent negative Eu anomalies coupled with significant LREE enrichment and HREE depletion indicating fractional crystallization with plagioclase separation. Elevated concentrations of Li (Avg. = 1355 ppm), Cs (Avg. = 246 ppm), Ta (Avg. = 124 ppm), Sr (Avg. = 105 ppm) and Rb (Avg. = 2234 ppm) coupled with their geochemical characteristics classify them as LCT type of rare-metal pegmatites. The relationship between La/Ta versus Mg/Li and Zr/Hf versus Nb/Ta attest that the studied samples are lithium mineralized pegmatites of magmatic-hydrothermal origin. Extremely low ratios of Mg/Li (0.004), K/Rb (0.004), K/Cs (0.05), K/Ba (0.07), Al/Ga (0.23) fingerprint that these pegmatites have evolved from highly fractionated, fertile parental granitic magma having promising economic potential.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"5 1","pages":"Article 100439"},"PeriodicalIF":0.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896118","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":"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":"2025-07-25","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":"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":"2025-07-21","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":"Hydrostratigraphic characterization using geoelectrostratigraphic information and hydraulic flow unit analysis for high-resolution aquifer mapping in heterogeneous systems","authors":"Ndifreke I. Udosen ,&nbsp;Kufre R. Ekanem ,&nbsp;Nyakno J. George","doi":"10.1016/j.geogeo.2025.100434","DOIUrl":"10.1016/j.geogeo.2025.100434","url":null,"abstract":"<div><div>Accurate characterization of aquifers requires comprehensive understanding of groundwater hydraulic properties. Traditional aquifer assessment techniques are usually insufficient in characterizing hydrostratigraphic variability, leading to inaccurate prediction of aquifer flow dynamics. To address these limitations, this work integrated geoelectrical stratigraphy with hydraulic flow unit, flow zone indicator, and stratigraphic modified Lorenz plot strategies, the goal being to enhance the resolution of aquifer characterization along river channels and tributaries in Akwa Ibom State, Southern Nigeria. Unlike conventional approaches, the stratigraphic modified Lorenz plot (SMLP) provided a more precise strategy for quantifying permeability distribution within the heterogeneous aquifer system, enabling enhanced prediction of aquifer performance. Furthermore, SMLP delineated flow efficiency across the distinct hydrostratigraphic units. Results indicated the presence of four hydraulic flow units, with individual units exhibiting distinctive transmissivity properties. Computed inclination angles of the four flow units were 34°, 29°, 49°, and 33°, respectively, and these indicated the extent of hydraulic efficiency. Hydraulic flow units 1, 3, and 4 had higher transmissivity and were key conduits for groundwater flow. Hydraulic flow unit 2, on the other hand, had reduced transmissivity, indicating restricted fluid migration. The techniques employed in this study enhanced subsurface characterization and generated high-resolution and cost-effective strategies for delineating high-yield aquifer zones within river channels and tributaries with better accuracy than with use of traditional hydrogeological models. These findings are important for optimizing groundwater resource management in the study area and analogous hydrogeological settings worldwide.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100434"},"PeriodicalIF":0.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724467","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":"Spatial distribution and source apportionment of potentially toxic elements in residential soil from Nsuta, a typical manganese mine community in Tarkwa, Southwestern Ghana","authors":"Eric Gyimah ,&nbsp;Samuel Kwamena ,&nbsp;Shadrack Fosu ,&nbsp;Emmanuel Daanoba Sunkari ,&nbsp;David Edem Dinku ,&nbsp;Yao Yevenyo Ziggah","doi":"10.1016/j.geogeo.2025.100435","DOIUrl":"10.1016/j.geogeo.2025.100435","url":null,"abstract":"<div><div>The environmental quality of residential areas of urban communities has been threatened by rapid industrial growth, substantial technological innovation, and urban expansion. The present study provides chemometric receptor model-based source apportionment, the ecotoxicological status, and the spatial distribution of arsenic, cadmium, lead, mercury, manganese and iron in residential soils in a mining community in Tarkwa. The distributions of the heavy metals showed a widespread pattern, while the eastern fringe of the study area was identified as a hotspot for mercury contamination. Agreement among the cluster analysis (CA), principal component analysis (PCA), and positive matrix factorization (PMF) along with the correlation matrix (CM) reasonably identified the sources of arsenic, manganese, and iron contamination of residential soils of the Nsuta community to be governed by geogenic influences such as the weathering and hydromorphic dispersion from the metavolcanic rocks. Noteworthily, atmospheric deposition is considered a prioritized source for mercury contamination, with a PMF contribution of 78.50%. Vehicular emission as well as other anthropogenic activities contribute to lead (48.00%) and cadmium (66.20%) contamination of the residential soil within the study area. Ecotoxicological assessment reveals a combined toxic risk index (TRI) of 29.80, with mercury contributing to about 97.50% of the total risk. Moreover, the modified hazard quotient (mHQ_i) for the single metals also indicated that mercury (Hg) has the highest ecological toxicity level with a mHQ_i value of 7.00. The present study provides baseline data that could be valuable for proper environmental management and policy-making to reduce the myriad influx of heavy metal contamination in the study area. To provide a thorough understanding of metal pollution in the Nsuta community, future research on metal speciation, bioavailability, bioaccumulation, potential modes of action in soils, and the implications for human health is also necessary.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100435"},"PeriodicalIF":0.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703996","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":"Accessory graphite in phyllites as indicator of metamorphic grade and stage (Szendrő Mts., NE Hungary)","authors":"Lívia Leskóné Majoros ,&nbsp;Máté Zs. Leskó ,&nbsp;Krisztián Fintor ,&nbsp;Ferenc Móricz ,&nbsp;Délia Bulátkó-Debus ,&nbsp;Sándor Szakáll ,&nbsp;Ferenc Kristály","doi":"10.1016/j.geogeo.2025.100431","DOIUrl":"10.1016/j.geogeo.2025.100431","url":null,"abstract":"<div><div>The metamorphic temperature of rock bodies can be estimated from the degree of graphitization of carbonaceous material, best determined by Raman spectroscopy. Graphite-bearing rocks from intensely folded black phyllites (black schists) near Meszes village in the Szendrő Mts., NE-Hungary, were analyzed using ore microscopy, scanning electron microscopy (SEM-EDX), X-ray powder diffraction (XRD), Raman spectroscopy and X-ray fluorescence spectrometry (XRF). The exposed Szendrő Phyllite Formation is of Carboniferous age, represents a gradually deepening basin fill, metamorphosed under greenschist facies conditions. Due to its low quantity and the presence of significant muscovite (± illite) 2M₁, clinochlore and quartz content, graphite is not directly detectable by XRD. Graphite occurs as intensely deformed 50–150 μm sized flakes persistently with kink-band microstructure and undulose extinction. The absence of S and Cl (confirmed by EDX) indicates a total maturation of the carbonaceous material into pure, disordered graphite with higher crystal ordering supported also by the initial splitting of S2 Raman band. The average formation temperature is estimated at 425°C (±50°C) by the Beyssac-method and 417°C (±50°C) by the Aoya-method.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 4","pages":"Article 100431"},"PeriodicalIF":0.0,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704106","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}