Journal of Geochemical Exploration最新文献

{"title":"Extreme H isotope fractionation of phyllosilicates from the Kiggavik Uranium deposits","authors":"Ian Burron ,&nbsp;Mostafa Fayek ,&nbsp;Julie Brown ,&nbsp;Alfredo Camacho","doi":"10.1016/j.gexplo.2025.107945","DOIUrl":"10.1016/j.gexplo.2025.107945","url":null,"abstract":"<div><div>The Kiggavik Uranium (U) Project in Nunavut, Canada hosts U deposits for which both unconformity-related and metasomatic‑iron-alkali-calcic genetic models have been proposed. We propose a five-phase genetic model consisting of: (1) albitization; (2) hematization and illitization; (3) bleaching and primary (U1) mineralization; (4) ∼1450 Ma to 274 Ma overprinting events linked to distant tectonic and igneous events, and: (5) geologically recent (∼471 Ka to 36 Ka) overprinting linked to subglacial meteoric fluids.</div><div>M2 muscovite formed during albitization of granitic rocks and is Ar-Ar dated to ∼1820–1830 Ma, which is consistent with igneous and seismic activity and albitite-hosted U mineralization in the region. M2 muscovite has δ²H values as high as +129 ‰. This high value is unprecedented in terrestrial minerals. M2 is in equilibrium with isotopically heavy (δ¹⁸O and δ²H values of +10.4 ± 2.1 ‰ and + 130 ± 31 ‰, respectively) fluids proposed to have been produced through multiple cycles of seismically-induced fluid boiling, phase separation, and condensation.</div><div>Multiple generations of illite, formed through retrograde metamorphic (Il1) and subsequent hydrothermal (Il2-Il5) processes, are present. Il3 and Il5 are isotopically consistent with precipitation from basinal fluids and with subsequent overprinting by meteoric fluids, while Il4 is isotopically consistent with highly fractionated, boiled fluids. Il3-Il5 illites yield post U1 Ar-Ar dates, reflecting overprinting events.</div><div>Highly fractionated fluids are strongly linked to albitization and an early albitite-style U mineralization event. Both highly fractionated and basinal fluids may have been involved in U1 mineralization. Basinal and meteoric fluids are strongly linked to post-depositional alteration events.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107945"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Triassic post-collisional porphyry systems in the eastern Kunlun Orogen, Northern Tibet: Insights from the Wulanwuzhu'er CuAg mineralization","authors":"Zhongyuan Ma ,&nbsp;Jinyang Zhang ,&nbsp;Yong Zhang ,&nbsp;Jianxun Yuan ,&nbsp;Jiaxing Chai ,&nbsp;Lanxin Zhang","doi":"10.1016/j.gexplo.2025.107943","DOIUrl":"10.1016/j.gexplo.2025.107943","url":null,"abstract":"<div><div>Intermediate-sulfidation epithermal deposits are known to be associated with porphyry Cu and high-sulfidation epithermal deposits but also have recently been reviewed to be related to low-sulfidation epithermal deposits in back arcs or post-collisional porphyry Mo deposits. In this study, the newfound low- to intermediate-sulfidation epithermal Ag<img>Pb<img>Zn mineralization is shown to be linked with the nearby Wulanwuzhu'er porphyry Cu deposit in the post-collisional setting of the eastern Kunlun Orogen based on field relationships, alteration and mineralization, zircon and rutile LA-ICP-MS U<img>Pb dating, and <em>in situ</em> sulfide trace elements and sulfur isotopes. Late Triassic porphyries intruded into deformed Devonian monzogranites along the fault zones were involved in the Wulanwuzhu'er Cu<img>Ag mineralization. The Ag<img>Pb<img>Zn mineralization includes pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, and argentite disseminated or in veins with kaolinization, sericitization, and chloritization. The Wulanwuzhu'er Cu deposit hosts veinlet-disseminated pyrite and chalcopyrite associated with potassic and sericitic alteration. Magmatic zircon in the Cu mineralized porphyry and magmatic hydrothermal rutile in Ag mineralized Devonian monzogranites yield similar LA-ICP-MS U<img>Pb ages of 213.2 ± 1.8 Ma and 211.7 ± 8.4 Ma, respectively. <em>In situ</em> trace elements and sulfur isotopes for pyrrhotite, six types of pyrite, and two types of chalcopyrite and sphalerite suggest that fluids for the Cu deposit ascended to shallow fault zones and underwent boiling to form the Ag mineralization. Therefore, other porphyry Cu, porphyry Mo, skarn Cu, and low- to intermediate-sulfidation epithermal Ag polymetallic deposits pertinent to Late Triassic post-collisional porphyries in the eastern Kunlun Orogen warrant further research and exploration for relevant styles of mineralization.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107943"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Portable X-ray fluorescence (pXRF) application to the determination of major and trace elements in large soil datasets for geochemical background assessment","authors":"Iker Martínez-del-Pozo ,&nbsp;Mónica Celina Gómez-Pachón ,&nbsp;Inmaculada Ferri-Moreno ,&nbsp;Mari Luz García-Lorenzo ,&nbsp;Saturnino Lorenzo ,&nbsp;José Ignacio Barquero-Peralbo ,&nbsp;Xabier Arroyo ,&nbsp;Pablo Higueras ,&nbsp;José María Esbrí","doi":"10.1016/j.gexplo.2025.107961","DOIUrl":"10.1016/j.gexplo.2025.107961","url":null,"abstract":"<div><div>Regional soil geochemical surveys are essential for land-use planning and human health. However, projects involving large sample sets characterised using traditional laboratory techniques are costly, time-consuming and require a large number of reagents. Therefore, the use of portable X-ray fluorescence (pXRF) with an optimised measurement time and methodology, along with minimal sample preparation, allows for fast and effective measurements. In this study, using Soil-Fundamental Parameters (S-FP) method, a measurement time of 45 s and low sample preparation yielded acceptable results for K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Rb, Sr, Zr, and Pb, which were monitored with benchtop XRF equipment. The application of this methodology in Cuenca province, Spain, and the comparison with different European and national programmes provides consistency in the results, despite using different analytical techniques. It was observed that a systematic and regular sampling strategy avoids geochemical gaps, increasing the representativeness of the soil parent material in the samples. Distinct geochemical patterns have been identified, with a major group comprising Ti, Mn and Fe, and trace elements such as Cr, Ni, Cu, Zn, As, Rb, Sr, Zr and Pb, while K, Ca and Sr display individual distribution trends. Therefore, this study provides a rapid and economical way to characterise soil geochemistry in large areas and to establish background and reference levels over extensive regions.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107961"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls on heavy metal variability in a coastal mountainous river: Impacts of tides, typhoons, and anthropogenic activities","authors":"Yalong Li ,&nbsp;Ni Su ,&nbsp;Yun Zhao ,&nbsp;Ergang Lian ,&nbsp;Chao Li ,&nbsp;Juan Xu ,&nbsp;Ping Yin ,&nbsp;Shouye Yang","doi":"10.1016/j.gexplo.2025.107944","DOIUrl":"10.1016/j.gexplo.2025.107944","url":null,"abstract":"<div><div>Understanding the ecological risks of heavy metals is critical for effective environmental management. Yet, the combined influence of tidal processes and tropical storms on heavy-metal dynamics in rivers remains poorly understood. This study examines the variations of heavy metals in sediments from a typical mountainous river in Southeast China, aiming to assess the combined influence of tides and typhoons on metal enrichment and ecological risks. The results show that from 2016 to 2019, there were no significant temporal changes in the ecological risks of heavy metals. Nevertheless, a distinct spatial pattern was observed, with higher levels in the tidal reach than in the non-tidal reach. This spatial variation is due to changes in sediment composition, such as shifts in source areas and grain size, which are driven by tidal processes. The clay fraction had significantly higher concentrations of heavy metals, enrichment, and ecological risks because metals are preferentially adsorbed onto fine-grained particles. Under normal conditions, tidal activity and anthropogenic inputs mainly affect the distribution of heavy metals. However, during typhoons, sediment mobilization intensifies, leading to a 2–4-fold increase in heavy metal concentrations and a higher risk of environmental contamination. The results of this study suggest that effective management of heavy-metal contamination in dynamic river systems requires a holistic approach that considers sediment composition, hydrodynamic conditions, and anthropogenic activities.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107944"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond principal component analysis: Nonparametric and nonlinear approaches for robust analysis of Gafsa basin groundwater","authors":"Ko Kumada ,&nbsp;Yoshiyasu Takefuji","doi":"10.1016/j.gexplo.2025.107962","DOIUrl":"10.1016/j.gexplo.2025.107962","url":null,"abstract":"<div><div>This paper critically examines methodological limitations in hydrochemical contamination studies, focusing on Principal Component Analysis (PCA) applications to the Gafsa basin in Tunisia. While PCA, as employed by Boschetti et al. (2025), effectively identified primary contamination sources from phosphate mining and agriculture, its inherent linearity assumptions fundamentally constrain its ability to represent complex environmental processes. We demonstrate how complementary methodologies—Feature Agglomeration, Independent Component Analysis, and High Variance Gene Selection—create a more comprehensive analytical framework capable of capturing nonlinear relationships, hierarchical structures, and statistically independent variation sources that PCA might overlook. This integrated approach enhances result reliability through methodological triangulation, providing environmental managers with more accurate contamination profiles that reflect the true complexity of groundwater systems.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107962"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing interpolation methods for GIS-based mapping of agricultural soil radioactivity","authors":"Spartak Hovhannisyan ,&nbsp;Nona Movsisyan ,&nbsp;Mane Kostanyan ,&nbsp;Kristina Sargsyan ,&nbsp;Konstantin Pyuskyulyan ,&nbsp;Olga Belyaeva","doi":"10.1016/j.gexplo.2025.107960","DOIUrl":"10.1016/j.gexplo.2025.107960","url":null,"abstract":"<div><div>Cross-validation of different interpolation methods - Inverse Distance Weighting (IDW), Ordinary Kriging, and Empirical Bayesian Kriging - was performed to map the spatial distribution of radioactivity in agricultural soils of Kotayk region, Armenia. Variogram analysis was used to characterize the spatial pattern of naturally occurring radionuclides (²²⁶Ra, ²³²Th, ⁴⁰K) and artificial radionuclide ¹³⁷Cs, as well as gross beta activity in soil.</div><div>Variogram results indicated weak spatial correlation for ²²⁶Ra and ⁴⁰K, reflecting regional-scale heterogeneity, while ²³²Th exhibited no discernible spatial structure, suggesting that its distribution is influenced primarily by highly localized processes. In contrast, the distribution of ¹³⁷Cs appeared to be influenced by a regional factor, altitude, in combination with local altitude-dependent factors. Mechanical disturbance caused by plowing reduced ¹³⁷Cs activity in arable lands, as the top 5 cm of soil, which is rich in ¹³⁷Cs, mixes with deeper layers that are poor in ¹³⁷Cs. These lands also showed the highest prediction errors compared to undisturbed land use types such as pastures and grasslands.</div><div>For gross beta activity, Ordinary Kriging with a Gaussian variogram model provided the most effective predictors, whereas an exponential variogram model performed best for ¹³⁷Cs. Empirical Bayesian Kriging proved most effective for mapping naturally occurring radionuclides. Overall, this comparative assessment of interpolation methods provides important methodological insights for improving spatial predictions of radionuclides in heterogeneous agricultural environments.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107960"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fertility assessment of the Kuh-e-Esfand porphyry Cu intrusion in SE Iran: Evidences from silicate chemistry","authors":"Alireza Zarasvandi ,&nbsp;Afsaneh Soltani ,&nbsp;Nader Taghipour ,&nbsp;Mohsen Rezaei ,&nbsp;Johann G. Raith ,&nbsp;Adel Saki ,&nbsp;Ghazal Zarasvandi","doi":"10.1016/j.gexplo.2025.107956","DOIUrl":"10.1016/j.gexplo.2025.107956","url":null,"abstract":"<div><div>The Kuh-e-Esfand porphyry copper prospect, situated 90 km southeast of Jiroft, is associated with Oligocene-Miocene Jebal-e-Barez-type intrusives in the Kerman Cenozoic Magmatic Assambladge (KCMA). In this area, quartz diorite, diorite, and granodiorite porphyry intrusions are emplaced within the Eocene Razak volcanic rocks. Hydrothermal alteration in the study area includes potassic, a deep potassic zone characterized by quartz, sericite, K-feldspar, chlorite ± anhydrite, phyllic, argillic, and propylitic zones. Mineralization, mainly as chalcopyrite and pyrite, occurs predominantly in the transition between potassic and phyllic zones, which extends mostly within the quartz diorite unit.</div><div>On the Al/(Ca + Na + K) vs. An (%) diagram, plagioclase data of quartz diorite units plot along the discriminating line of barren and fertile porphyry Cu intrusions with a more tendency to fertile field (average Al/(Ca + Na + K) = 1.3). Ca- amphiboles in the quartz diorite intrusion are classified as low-Al (Al_T = 0.7–1.6) and high-Al (Al_T = 1.9–2.12) groups. Low-Al amphiboles, characterized by lower water content and higher chlorine concentrations are crystallized at lower temperatures (720.9–0.8 °C), pressures (0.51–0.89 kbar), and under more oxidizing conditions (ΔNNO = 1.47–1.96), compared to high-Al amphiboles, which formed at higher temperatures (866.5–921.7 °C), pressures (1.94–4.02 kbar), and lower oxidation states (ΔNNO = 0.99–1.05). Low-Al amphiboles formed under conditions more favorable for mineralization. Furthermore, re-equilibrated biotites are of Mg-rich, showing high Mg/(Mg + Fe) ratios with low Mn and Al^VI values, which is analogous to those of fertile porphyry Cu intrusions. Geochemical data indicate a hydrous/oxidized calc-alkaline I-type magma that drived from the interaction of mantle-derived magmas with crustal materials in a subduction-related geotectonic setting. The geological, magmatic and geochemical characteristics of the Kuh-e-Esfand prospect are consistent with porphyry Cu mineralization potential.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107956"},"PeriodicalIF":3.3,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal notice to “Ore-forming processes of the Chuankou tungsten ore field, South China: New insights into Maowan quartz veins scheelite generation and mineralization genesis” [GEXPLO 278(2025) 107864]","authors":"Or Aimon Brou Koffi Kablan ,&nbsp;Binhai Wang ,&nbsp;Yuzheng Shi ,&nbsp;Syed Yasir Ali Shah ,&nbsp;Baoyi Zhang","doi":"10.1016/j.gexplo.2025.107910","DOIUrl":"10.1016/j.gexplo.2025.107910","url":null,"abstract":"","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107910"},"PeriodicalIF":3.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ RbSr dating of hydrothermal sericite constrains Paleocene-Eocene PbZn mineralization in eastern Gangdese to India-Asia collisional tectonics","authors":"Zezhang Yu ,&nbsp;Xin Chen ,&nbsp;Xiaoyi Wang ,&nbsp;Yu Liu ,&nbsp;Dongrui Zhang ,&nbsp;Xiaojia Jiang ,&nbsp;Nan Chao ,&nbsp;Youye Zheng ,&nbsp;Shunbao Gao","doi":"10.1016/j.gexplo.2025.107932","DOIUrl":"10.1016/j.gexplo.2025.107932","url":null,"abstract":"<div><div>Dating Pb<img>Zn polymetallic deposits is challenging due to low-temperature hydrothermal formation and common detachment from obvious magmatic sources, which often limits the availability of datable minerals. A prime example of this issue is observed in the eastern Gangdese metallogenic belt of Xizang, a globally significant province characterized by skarn-style and hydrothermal vein-type Pb<img>Zn polymetallic systems. Despite their economic importance, the absolute timing of mineralization in these deposits remains contentious, with competing hypotheses invoking Paleozoic submarine exhalative sedimentation, Cenozoic magmatic-hydrothermal activity, or multistage metallogenic pulses linked to episodic tectonic events. To address this, we integrate in situ Rb<img>Sr dating of micas with U<img>Pb zircon/monazite geochronology and geochemistry for the Bagaladong and Mengya'a deposits. At Bagaladong, magmatic zircon/monazite from altered granite yields a crystallization age of 130 ± 3 Ma, while muscovite gives an alteration/cooling age of 110 ± 2 Ma. Critically, hydrothermal sericite from mineralization veins yields ages of 55.8 ± 2.4 Ma (skarn-type mineralization) and 49.0 ± 0.3 Ma (vein-type mineralization), revealing a significant temporal gap from the associated magmatism. For the Mengya'a deposit, hydrothermal sericite (coeval with galena-sphalerite) yields an age of 53.0 ± 4.0 Ma, which is consistent with prior <em>Re</em><img>Os and garnet U<img>Pb data from the region. These results definitively refute Paleozoic or Mesozoic origins, instead establishing Paleocene-Eocene mineralization linked to concealed intrusions. The timing precisely coincides with the ∼55–45 Ma phase magmatic peak in the Gangdese batholith, suggesting a genetic association with Neo-Tethyan slab rollback during the India-Asia collision. This investigation highlights the analytical potential of in situ Rb<img>Sr dating for hydrothermal sericite, representing a methodological advancement particularly applicable to low-temperature metallogenic systems where conventional datable minerals are absent but sericitic alteration is pervasive.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107932"},"PeriodicalIF":3.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145594701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineral weathering and water chemistry of pyrrhotite- and serpentine-bearing mine wastes under freeze-thaw cycles","authors":"Gary Schudel ,&nbsp;Bruno Bussière ,&nbsp;Joyce M. McBeth ,&nbsp;Benoît Plante","doi":"10.1016/j.gexplo.2025.107933","DOIUrl":"10.1016/j.gexplo.2025.107933","url":null,"abstract":"<div><div>The mineralogical composition of mine wastes is generally considered to be the most important determinant of mine water geochemistry. However, environmental factors can significantly modify the weathering behavior of these materials, and the failure to consider these factors in experimental work may yield biased results. This is a particularly important consideration for mines in arctic and sub-arctic regions, where environmental conditions are far from those of a typical laboratory. The present study focuses on evaluating the influence of ambient thermal conditions on the weathering of pyrrhotite- and serpentine-rich tailings. To this end, laboratory-scale leached columns were used to simulate weathering of tailings over 544 days either at room-temperature or under freeze-thaw cycles (−20 °C/+20.5 °C). Microbiological analyses performed as part of the initial material characterization were unable to detect microbial communities. Although this result was unexpected and unusual, we found that elemental sulfur, which is stable in the absence of sulfur-oxidizing bacteria, had accumulated in the weathered tailings, representing up to 89–92 % sulfur products from pyrrhotite oxidation. Thiosulfate and sulfate were important oxidation products in leachates under both thermal conditions; however, freeze-thaw cycling appeared to enhance the stability of thiosulfate. The dominance of elemental sulfur and thiosulfate, which are produced via non-acid-generating reactions, suggests that the hydrolysis of Fe³⁺ and Al³⁺ may have been comparatively important sources of acid generation. Serpentine dissolution was more extensive at room-temperature but likely provided little to no alkalinity under freeze-thaw conditions due to slower dissolution kinetics. Calcite and dolomite were the principal buffering phases despite their low abundance. The mobility of Zn seemed to not be limited in either test, whereas Fe and Ni were effectively sequestered via adsorption and/or coprecipitation with ferrihydrite and gibbsite. Under room-temperature conditions, depletion or passivation of the carbonate minerals gave rise to a new buffering regime controlled by gibbsite. Although this maintained the pH around 5.1, aqueous Fe and Ni concentrations spiked (max = 7.6 and 1.5 mM, respectively) as they were released or desorbed from the gibbsite. Leachate pH values remained slightly elevated in the freeze-thaw tests and had not yet stabilized by the end of the experiment; the sequestration of Fe and Ni was not disrupted.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107933"},"PeriodicalIF":3.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}