Applied Geochemistry最新文献

{"title":"Provenance of oilfield brines and vertical connectivity of Middle to Upper Jurassic sequence in eastern Saudi Arabia","authors":"Peter Birkle ,&nbsp;Ahmed J. Zayer","doi":"10.1016/j.apgeochem.2025.106673","DOIUrl":"10.1016/j.apgeochem.2025.106673","url":null,"abstract":"<div><div>Knowledge of reservoir connectivity is crucial for optimizing oil recovery, accurately estimating reserves, planning well placement, and improving economics of an oil field. This study combines hydrochemical (major, minor, trace elements) and multi-isotopic techniques (δ²H, δ¹¹B, δ¹³C, ¹⁴C, δ¹⁸O_H2O, δ¹⁸O_SO4, δ³⁷Cl, δ⁸¹Br, δ³⁴S_SO4, ⁸⁷Sr/⁸⁶Sr) on oilfield brines to define reservoirs dynamics by tracing fluid provenance and migration. As case study, preserved bottom-hole water samples were recovered along a 1930’ vertical column of seven groundwater horizons from a Middle to Upper Jurassic carbonate-anhydrite sequence in an exploratory well in the eastern region of Saudi Arabia. Geochemical fluid homogeneities reveal hydraulic connectivity between the Lower Tithonian and Upper Kimmeridgian sequence, suggesting the presence of a single reservoir. Isotopic heterogeneities reveal sealing conditions between underlying Lower Kimmeridgian, Oxfordian (Hanifa), and Bathonian (Upper Dhruma) groundwater systems. Interlayered anhydrite strata resulted in possessing ambivalent hydrodynamic functionalities, either as conduits or seals. Studied formation waters are composed of Na–Cl to Na–Ca–Cl water type with a descending salinity from 210,500 mg/L (Tithonian) to 147,800 mg/L (Bathonian). Measured ¹⁴C concentrations from 2.01 pmC to 18.77 pmC point to recharge of the Jurassic sequence by infiltrating surface water during Late Pleistocene and Early Holocene, causing the mixing and partial replacement between 37 % and 55 % of fossil oilfield brine. A positive vertical trend of δ¹⁸O_SO4 - δ³⁴S_SO4 ratios, δ¹³C_PDB values between +8.4 ‰ and +16.2 ‰, and depleted δ¹¹B ratios reveal thermocatalytic sulfate reduction, methane production, and desorption of clay material, respectively, as major secondary water-rock interaction processes. As practical benefit, formation water analyses provide a low-cost and low-risk complementary tool to expensive and failure-prone production logging tools for evaluating reservoir conditions. The geochemical detection of hydraulic connectivity or compartmentalization between stratigraphic units represents a complimentary tool to trace the analogue migration of hydrocarbons within single or multiple pay zones.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106673"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"H–O–B–Li isotope systematics for assessing slab-derived fluids: Importance of postdehydration processes","authors":"Rofiqul Umam ,&nbsp;Ikuya Adachi ,&nbsp;Tsutomu Yamanaka","doi":"10.1016/j.apgeochem.2025.106667","DOIUrl":"10.1016/j.apgeochem.2025.106667","url":null,"abstract":"<div><div>In this study, the isotopic alteration of boron (B) and lithium (Li) in slab-derived fluids after they undergo dehydration processes is investigated using deep groundwater samples from the eastern Kii Peninsula of Japan. Isotopic and elemental analyses of hydrogen (H), oxygen (O), B, and Li reveal complex subsurface fluid mixing and geochemical interactions that exceed simple meteoric recharge. Three distinct groundwater groups were identified on the basis of δ²H–δ¹⁸O–Cl relationships: Group I has strong slab-derived water signatures, particularly along the Median Tectonic Line and near 34°50′N, with up to 60 % slab-derived contributions; Group II reflects mixing between meteoric water and ocean water; and Group III is predominantly meteoric. Spatial variations in δ¹¹B and δ⁷Li isotopes suggest that local geochemical processes such as clay adsorption, silicate weathering, and igneous rock contributions significantly alter the original slab-derived isotopic signals. Rayleigh-type fractionation models explain the increased isotopic values in some wells, whereas low δ¹¹B and δ⁷Li values elsewhere indicate localized sources. Notably, high Li values with low δ⁷Li values in the southwest indicate a Li supply from Miocene igneous intrusions beneath the Mesozoic accretionary complex. These findings highlight the need for an integrated multi-isotope approach to accurately trace fluid origins and reconstruct the geochemical pathways of slab-derived fluids in forearc groundwater systems.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106667"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrate aerosol and dust pollution evidence from a non-central-heating county in China","authors":"Mingya Wang ,&nbsp;Wenju Wang ,&nbsp;Mingshi Wang ,&nbsp;Xuechun Zhang ,&nbsp;Baoxian Jia","doi":"10.1016/j.apgeochem.2025.106675","DOIUrl":"10.1016/j.apgeochem.2025.106675","url":null,"abstract":"<div><div>As urbanization in China has shifted from major cities to surrounding counties, the study of PM_2.5 in these areas has gained significant attention. However, the pollution characteristics and sources of winter PM_2.5 in noncoal-heating counties in China remain unclear. In this study, PM_2.5 samples were collected from both urban and suburban functional areas in Xixian County, China. The mean PM_2.5 concentrations at the Xizhou Hotel (urban) and Primary School (suburban) sites were 81.4 ± 28.2 and 97.1 ± 35.7 μg/m³, respectively, with higher concentrations observed at the suburban site than at the mixed commercial and residential site. Two distinct haze types were identified: the first, dominated by Ca and Al, was primarily caused by windblown dust, including construction dust and soil dust from abandoned farmlands. The second, dominated by NO₃⁻, SO₄²⁻, and NH₄⁺, resulted from the secondary oxidation of primary gaseous precursors. Secondary pollutants (53.0 %) and vehicular traffic (24.9 %) were the major contributors. This study provides valuable data on the chemical characteristics and sources of winter haze in noncoal heating counties, providing a scientific basis for global PM_2.5 control strategies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106675"},"PeriodicalIF":3.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145904063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability of barite in thermochemical sulfate reduction: implications for primeval organic component preservation and metal sulfide mineralization","authors":"Yuan Wei ,&nbsp;Qian Wan ,&nbsp;Wenxuan Hu ,&nbsp;Xiaolin Wang","doi":"10.1016/j.apgeochem.2025.106666","DOIUrl":"10.1016/j.apgeochem.2025.106666","url":null,"abstract":"<div><div>Thermochemical sulfate reduction (TSR) is a common organic-inorganic interaction where sulfates react with hydrocarbons at elevated temperatures, producing reduced sulfur and oxidized carbon. The stability of barite in TSR is a critical scientific question because barite-hosted inclusions are reported to record primeval organic matters and barite can be involved in the formation of Sedimentary Exhalative and Mississippi-Valley type deposits. Here we performed systematic hydrothermal experiments and thermodynamic simulations to identify the key factors controlling TSR between barite and hydrocarbons. Results show that in anhydrous and neutral aqueous environments, barite and hydrocarbons can coexist stably at temperatures below 150 °C. Such condition is comparable with that reported for the formation of ∼3.5 Ga barite in Pilbara Craton, Western Australia, indicating that barite-hosted inclusions can record original information for Archean life evolution. At higher temperature and low pH conditions, barite can react with hydrocarbon to generate H₂S and CO₂. Fluid acidity (i.e., H⁺ concentration) and temperature are the most prominent factors controlling the involvement of barite in TSR. Therefore, consumption of preexisting H₂S (either TSR or other origin) by precipitation of metal sulfides (e.g., sphalerite and galena) can generate excess H⁺, which favors the involvement of barite in TSR. Obviously, barite can serve as a sulfur source for the formation of metal sulfide deposits. In conclusion, our findings offer new insights into researches of early Earth environments and the mineralization mechanisms of metal deposits.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106666"},"PeriodicalIF":3.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of electrode geometry on electrokinetic removal of heavy metals and salt ions from co-contaminated soils","authors":"Öznur Karaca ,&nbsp;Sonam Taneja ,&nbsp;Çetin Kantar ,&nbsp;Anil Kumar Haritash","doi":"10.1016/j.apgeochem.2025.106655","DOIUrl":"10.1016/j.apgeochem.2025.106655","url":null,"abstract":"<div><div>This study evaluated the performance of electrokinetic remediation on multi-metal-contaminated soil based on three electrode configurations: linear (1 anode–2 cathodes), trigonal (1 anode–2 cathodes), and square (1 anode–4 cathodes). The effects of co-contaminants and inter-ionic interferences on metal migration and removal were critically assessed. The findings revealed that the square configuration exhibited better removal efficiencies due to its improved electric field distribution and higher cathode coverage. With the same number of electrodes, the linear arrangement exhibited slightly better removal than the trigonal design, suggesting that spatial arrangement is a key factor in EK performance. The maximum removal was achieved for hexavalent chromium (Cr (VI)), followed by cadmium and lead, mainly because of the high complexation affinity of Cr (VI) for EDTA. Speciation analysis by Visual MINTEQ showed evidence of stable Cr–EDTA complexes being formed, allowing their mobilization. Introduction of EDTA not only enhanced the transport and solubility of target metals but also favoured the migration of natural cations (Na⁺, K⁺, Mg²⁺, Ca²⁺). In addition, harmful anions, SO₄²⁻ and Cl⁻ were reduced by 90 % and 80 %, respectively. The economic analysis confirmed the square configuration as the most cost-effective, with specific energy consumption (50 kWh/m³/g) and specific cost (701.5 US$/g). The study highlights the critical role of electrode arrangement in optimizing EKR processes and the mobilization and removal of heavy metals from polluted soils.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106655"},"PeriodicalIF":3.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unique migration-distribution processes and pollution risks of typical elements from geothermal spring discharge: A systematic assessment on Gudui geothermal field (southern Tibet)","authors":"Xiuying Yang ,&nbsp;Hongbing Tan ,&nbsp;Zhiwei Shi ,&nbsp;Hongkai Zhu ,&nbsp;Kang Qiang ,&nbsp;Hao Long","doi":"10.1016/j.apgeochem.2025.106656","DOIUrl":"10.1016/j.apgeochem.2025.106656","url":null,"abstract":"<div><div>The Gudui geothermal field in southern Tibet, China's second-largest non-volcanic high-temperature geothermal system, exhibits vigorous hydrothermal activity, with widespread geothermal springs discharging harmful elements that threaten around environment. However, the enrichment and migration mechanisms of hazardous elements during geothermal spring discharge remain unclear, in particular, the unusual enriched and highly hazardous elements like Tl has not been drawn attention by previous researches. This study focuses on a high-temperature geothermal spring discharge area in Karugou watershed in Gudui and systematically track the distribution and partition law of As, Tl, and B in geothermal deposits, river water, sediments, and around farmland soils. Results indicate that concentrations of As, Tl, and B progressively increase along the river, with corresponding trends observed in sediments. Concentration of these elements exceed basic permission limits by 302.22, 1326.61 and 15.16 times, respectively. In farmland soils irrigated with river water, As and Tl levels at 40 cm depth exceed natural soil by 1.2 times, while surface B concentrations are over 4.2 times. Harmful elements from geothermal discharge exhibit systematic migration-distribution-partition patterns in geothermal deposits, river sediments, and soils, where elements first accumulate in geothermal deposits, with partial partitioning into travertine or sinter. With respect to As and B that enrich more in general travertine, Tl prefers to be enriched in sinter. Irrigation has distinctly introduced these elements into downstream farmland soils (0–40 cm). Such high enrichment poses significant potential environmental risks. Future geological events like tectonic activities, floods, or large-scale development could trigger massive release of these harmful elements from geothermal fluids or remobilization from river sediments, potentially endangering downstream populated areas. This study firstly highlights the uncommon natural hazardous elements like Tl enriched in geothermal spring and provides a reference for environmental impact assessments of geothermal exploitation in Tibet as well as worldwide.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106656"},"PeriodicalIF":3.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of Al substitution on the structures and properties of iron (oxyhydr)oxides and their environmental implications","authors":"Junkun Yan ,&nbsp;Jingjing Hu ,&nbsp;Lingyi Li ,&nbsp;Wei Cheng","doi":"10.1016/j.apgeochem.2025.106653","DOIUrl":"10.1016/j.apgeochem.2025.106653","url":null,"abstract":"<div><div>Aluminum (Al) substitution for Fe(III) in iron (oxyhydr)oxides is a widespread phenomenon that significantly modifies the minerals' physicochemical structural properties and reactivity, thereby influencing the environmental behavior of contaminants. Despite the importance of Al-substituted iron (oxyhydr)oxides in geochemical processes, a comprehensive analysis of their structural properties and reactivity has been lacking. This review critically examines the effects of Al substitution on iron (oxyhydr)oxide crystal structure, morphology, surface charge, hydroxyl group characteristics, and recrystallization dynamics. We then elucidate how these structural alterations modulate the adsorption capacity for key environmental contaminants (heavy metals, metalloids, organic compounds, inorganic anions) and influence redox and catalytic processes crucial for contaminant transformation. This work provides essential insights for predicting contaminant behavior in diverse geological settings and inform the design of tailored remediation technologies. Future research directions are proposed to advance understanding of Al-substituted iron (oxyhydr)oxides in critical environmental processes.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106653"},"PeriodicalIF":3.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling transport of natural tracers through a Mesozoic aquitard sequence in northern Switzerland","authors":"Jin Ma ,&nbsp;Thomas Gimmi ,&nbsp;Paul Wersin ,&nbsp;Daniel Traber ,&nbsp;Michael Schnellmann","doi":"10.1016/j.apgeochem.2025.106654","DOIUrl":"10.1016/j.apgeochem.2025.106654","url":null,"abstract":"<div><div>Analysing and modelling profiles of natural tracers in rock porewater contribute substantially to the understanding of palaeo-transport processes in clay rocks. Following a recent deep-drilling campaign in northern Switzerland, a large dataset from eight boreholes has become available. It reveals detailed rock and porewater characterisation and provides insights into the investigated 600-700 m-thick Mesozoic succession, which includes a large central aquitard sequence with more than 100 m thick Opalinus Clay. The aquitard sequence is sandwiched between the Malm aquifer (towards the east) or the Hauptrogenstein aquifer (HRS, towards the west) at the top and the Keuper or Muschelkalk aquifers at the base. This study aimed to model and reproduce the high-resolution profiles of four different natural tracers (δ¹⁸O, δ²H, Cl⁻, and Br⁻) from these boreholes using a one-dimensional transport model. The model incorporated diffusion properties dependent on temperature, clay-mineral content, and formation-specific anion-accessible porosities. Good agreements were found between the modelled and measured profiles considering diffusive transport and consistent evolution times (i.e., times when groundwater composition changed) for all four tracers. These times were estimated individually for each borehole, suggesting values between 0.1 and 0.7 Ma for the Keuper aquifer, longer times (mostly several Ma, range of 0.6–3 Ma) for the Malm aquifer, and shortest times (mostly less than 150 ka, range of 0.02–0.3 Ma) for the Muschelkalk aquifer. These estimates are broadly consistent with the current knowledge on the palaeo-hydrogeology of the studied region. Extensive sensitivity analyses were performed to assess the impact of various modelling assumptions and simplifications on the fitting quality and estimated evolution times. Variations with regard to assumed initial conditions (within plausible ranges) and palaeo temperatures had only minor effects, while variations of diffusion coefficients or positions of conductive zones can affect local profile shapes and thus evolution times. Finally, no evidence of potential cross-formation flow between the overlying and underlying aquifers (Malm and Keuper) could be identified from simulations including advective transport.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106654"},"PeriodicalIF":3.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional geochemical prospecting for Li–Be rare earth deposits: A case study in Southern Xinjiang, China","authors":"Jingjing Gong ,&nbsp;Lujun Lin ,&nbsp;Jianweng Gao ,&nbsp;Yingjie Gao ,&nbsp;Hui Wu ,&nbsp;Yong Li ,&nbsp;Jianzhou Yang ,&nbsp;Zhuang Duan ,&nbsp;Zuohuai Yang ,&nbsp;Shixin Tang","doi":"10.1016/j.apgeochem.2025.106651","DOIUrl":"10.1016/j.apgeochem.2025.106651","url":null,"abstract":"<div><div>The exploration of critical minerals, such as lithium (Li) and beryllium (Be), plays a vital role in supporting various high-tech industries. The southern margin of Xinjiang, China, which extends from the Western Kunlun to the Altun Mountains, has revealed promising Li–Be rare metal deposits—including the Dahongliutan and Washixianan occurrences—suggesting considerable potential for further discoveries. Regional-scale geochemical surveys (ranging from 1:200,000 to 1:500,000) have provided extensive coverage of this area, yielding abundant geochemical data. While these datasets were originally collected decades ago, their full potential for identifying rare metal deposits via modern compositional data analysis (CoDA) methods has not been fully realized. In this study, we reuse these existing regional geochemical data and apply the isometric log-ratio robust principal component analysis (ilr-RPCA) method to develop a novel composite indicator for effectively delineating pegmatite-type Li–Be deposits. The results indicated that although conventional geochemical anomalies of Li and Be correlate well with known deposits, the intensity and spatial distribution of mineralization-related anomalies vary significantly, potentially leading to the omission of certain mineralized anomalies. Through ilr-RPCA, two distinct element associations were identified: (1) Li, Be, and B, which are closely linked to pegmatite-type Li–Be mineralization, and (2) La, Y, Zr, and Nb, representative of the geochemical background associated with acidic rock formations. Anomaly maps derived from the ratio between these two groups accurately pinpoint the locations of pegmatite-type Li–Be deposits, demonstrating the effectiveness of the CoDA approach in geochemical prospectivity mapping. Based on this approach, four prospective areas for rare metal mineralization have been delineated. This methodology offers practical guidance for mineral exploration companies and government agencies in their decision-making processes.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"197 ","pages":"Article 106651"},"PeriodicalIF":3.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactive pathways of synthetic forsterite and Mg/Ni-serpentine: Insights into incipient dissolution and carbonation","authors":"Mattia Corti ,&nbsp;Daniela D'Alessio ,&nbsp;Mara Murri ,&nbsp;Giancarlo Capitani ,&nbsp;Marcello Campione ,&nbsp;Nadia Malaspina","doi":"10.1016/j.apgeochem.2025.106650","DOIUrl":"10.1016/j.apgeochem.2025.106650","url":null,"abstract":"<div><div>Carbon capture, utilisation and storage is among the key strategies to mitigate the increasing concentration of atmospheric carbon dioxide. Mineral carbonation stands out as a promising solution for long-term carbon sequestration by exploiting Ca–Mg-bearing oxides, hydroxides, and silicate minerals such as olivine and serpentine. Although the reaction occurs spontaneously in nature, it is strongly hindered by mineralogical and structural factors.</div><div>In this study, nanocrystalline pure forsterite and Mg- and Ni-endmember serpentines were synthesised as model phases to disentangle the role of composition, crystal structure, and morphology in incipient dissolution and carbonation and to maximise reactivity through increased surface-to-volume ratios. The choice of Ni-serpentine endmember aims to investigate the fate of Ni after dissolution and carbonation, considering that in nature serpentine can incorporate up to 0.5 wt% of nickel oxide. A systematic experimental strategy was designed to investigate their early-stage dissolution and carbonation behaviour under mild hydrothermal conditions (100 °C, <em>p</em>CO₂ ≤ 6 bar), using microwave-assisted treatments in a controlled environment. The products were thoroughly characterised, both as solid precipitates and aqueous components, through X-ray Powder Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, micro-Raman and Inductively Coupled Plasma – Optical Emission Spectroscopy. This direct, parallel comparison reveals distinct behaviours among the tested materials, with forsterite and Mg-serpentine releasing Mg into solution and promoting the formation of hydrated Mg-carbonates, whereas Ni-serpentine nanocrystals remain largely inert, immobilising Ni within their structure. These findings have potential implications not only for carbon dioxide sequestration but also for critical metal recovery processes.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"196 ","pages":"Article 106650"},"PeriodicalIF":3.4,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}