Journal of Geochemical Exploration最新文献

{"title":"Improving the performance of contamination indices by accounting for local baselines in stream sediment: A sample catchment basin approach","authors":"Iannone Antonio,&nbsp;Dominech Salvatore,&nbsp;Pacifico Lucia Rita,&nbsp;Guarino Annalise,&nbsp;Albanese Stefano","doi":"10.1016/j.gexplo.2025.107860","DOIUrl":"10.1016/j.gexplo.2025.107860","url":null,"abstract":"<div><div>Geochemical prospecting serves as a fundamental approach for examining the influence of geological settings on stream sediment composition and identifying natural or anthropogenic geochemical anomalies within a river catchment. Various indices have been developed to assess sediment quality and environmental status, typically based on ratios between observed element concentrations and reference values representing undisturbed conditions. However, these reference values often fail to account for the influence of river dynamics on sediment variability, potentially compromising the reliability of contamination assessments. Since the chemical composition of stream sediments reflects the cumulative influence of their upstream catchment basins, the dilution correction method has been extensively employed in previous studies to mitigate the dilution effects caused by fluvial processes. To address this, the present study evaluates whether local geochemical baselines can improve the performance of contamination indices. The Sarno River basin, heavily impacted by urban and industrial activities, was selected as a case study. Ninety-six sediment samples were analysed using geomorphological and hydrological parameters to define each Sample Catchment Basin (SCB). Baseline concentrations of Cd, Cr, Cu, Hg, Ni, Pb, Sb, and Zn were then estimated by calculating the weighted average element content based on lithological unit proportions within each SCB. Then, contamination indices were computed using both uncorrected (raw) and SCB-corrected baselines and spatially mapped. The use of SCB-based reference values led to a 23 % increase in the detection of high-impact sites using the Enrichment Factor and a 366 % increase using the Contamination Factor, revealing a substantial underestimation of contamination in the raw approach. Comparative analysis also showed a more balanced distribution of element contributions in the corrected indices, indicating improved representativeness of multi-element contamination. These results highlight the advantages of incorporating local baseline variability into geochemical evaluations, providing a more accurate and spatially consistent framework for environmental risk assessment in fluvial systems.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107860"},"PeriodicalIF":3.4,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570303","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":"Enhancing lithium exploration in the Borborema province, Northeast Brazil: Integrating airborne geophysics, low-density geochemistry, and machine learning algorithms","authors":"Guilherme Ferreira da Silva ,&nbsp;Raphael Teixeira Correa ,&nbsp;Rogério Celestino de Almeida","doi":"10.1016/j.gexplo.2025.107861","DOIUrl":"10.1016/j.gexplo.2025.107861","url":null,"abstract":"<div><div>The increasing demand for lithium, driven by its essential role in renewable energy technologies, implies the development of innovative exploration techniques. This study applies Random Forest regression integrated with low-density geochemistry and airborne gamma-ray data to enhance the resolution and accuracy of lithium concentration maps in soils across the Borborema Province, Northeast Brazil. Our methodology not only refines the mapping of lithium distributions but also identifies potential lithium-rich zones within established and underexplored areas. The predictive model successfully delineates regions with high lithium content (up to 70 ppm), aligning these with known geological features and pegmatite occurrences, thereby validating the model's robustness despite some challenges in predicting extreme values. The research highlights the presence of lithium beyond traditional pegmatite deposits, suggesting a broader geological context for lithium mineralization. Our findings encourage strategic targeting of exploration efforts, which can lead to more economical mining practices. This study demonstrates the potential of integrating advanced data analytics with traditional geological methods to improve the efficiency and reach of lithium exploration, supporting the global transition towards renewable energy sources. Future work should enhance model accuracy, especially at extreme concentration levels, and expand the model's application to other regions with similar geological settings.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107861"},"PeriodicalIF":3.4,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572790","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":"Multivariate compositional analysis of groundwater geochemistry in the Georgina Basin: New insights for sediment-hosted mineral systems","authors":"Ivan Frederick Schroder ,&nbsp;Patrice de Caritat ,&nbsp;David Huston ,&nbsp;David Champion","doi":"10.1016/j.gexplo.2025.107857","DOIUrl":"10.1016/j.gexplo.2025.107857","url":null,"abstract":"<div><div>The Georgina Basin in northern Australia holds significant potential for strategic minerals, particularly zinc and phosphate, which are crucial for Australia's economy and transition to net-zero. This study applied multivariate statistical tools to groundwater geochemistry from the basin's regional Cambrian Limestone Aquifer to investigate the prospectivity of sediment-hosted phosphate and Zn–Pb mineral systems in the northern half of the Georgina Basin. Robust principal component analysis (rPCA) identified Mo and I⁻ (as well as Rb and Al) as key elements associated with the variation of P in groundwater. K-means cluster analysis then mapped a subset of spatial clusters where these P relationships were evident. This investigation culminated in the creation of a new geochemical index (<em>Phos#</em>) for identifying hydrogeochemical anomalies likely sourced from phosphate mineralisation. Five areas were deemed most prospective using <em>Phos#</em>: three near Elliott, and one in each of the Central Georgina and Undilla Sub-basins.</div><div>The hydrogeochemistry was also valuable in detecting regional sediment-hosted Zn–Pb mineralisation. Radiogenic Pb-isotope outliers (²⁰⁶Pb/²⁰⁴Pb of 22.00 to 24.00) in the Alexandria-Wonarah Basement High and Undilla Sub-basin (which were supported by elevated Pb or Zn in groundwater), were spatially correlated with observed sulfides at the surface or in drillholes and consistent with the radiogenic Pb-isotope signature of Georgina Basin's Joplin-type, Mississippi Valley Type Zn–Pb mineralisation.</div><div>This regional in-depth assessment of the groundwater chemistry provides an efficient scale-reduction tool with clear targets for follow-up, and is supported by a discussion on how this multivariate, index-based approach can be translated to other sedimentary basins and/or mineralisation assemblages.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107857"},"PeriodicalIF":3.4,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695284","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":"The role of ore-forming conditions in high germanium enrichment of colloform sphalerite: A case study of the Banbianjie deposit, SW China","authors":"Guotao Sun ,&nbsp;Jia-Xi Zhou ,&nbsp;Alexandre Cugerone ,&nbsp;Lingli Zhou ,&nbsp;Kai Luo ,&nbsp;Maoda Lu","doi":"10.1016/j.gexplo.2025.107862","DOIUrl":"10.1016/j.gexplo.2025.107862","url":null,"abstract":"<div><div>Colloform sulfides host significant germanium (Ge) resources in South China. The Banbianjie deposit, situated in southwest China, is a carbonate-hosted Zn-Ge deposit (0.8 Mt. @ 1.78 to 9.50 % Zn and &gt; 800 t @ 100–110 ppm Ge) and is rich in colloform sphalerite with widespread occurrence of Ge-rich nanoparticles. Previous studies documented that Ge enrichment in sphalerite may be correlated to internal mechanisms, however, the impact of external factors, such as source and fluid mixing, on Ge enrichment is poorly understood. In this study, we applied in situ trace elements and S-Pb isotopic compositions to interpret the external controls influencing Ge distribution. New laser-ablation inductively coupled mass spectroscopy (LA-ICP-MS) analyses reveal that sphalerite contains very heterogeneous Ge contents from 221 to 1916 ppm (mean = 843 ppm Ge), positively correlating with Fe, Mn, and Pb and negatively with Cd concentrations. Sulfur isotopic compositions infer a predominant sulfur source (~ − 10 ‰) and a subordinate sulfur source (~ − 1 ‰). The Pb isotopic ratios of sphalerite plot on the upper crust curve, indicating a crustal source for the metals. The sulfur isotope geothermometer estimates the formation temperatures of sphalerite mainly below 250 °C and pH changes may cause the transition of sulfide phases. Trace elements and δ³⁴S values indicate a predominant Ge-rich fluid and a subordinate Cd-rich fluid. The influxes of Cd-rich fluid are correlated with local Ge-poor zonings in sphalerite. We propose that fluid mixing can locally influence the Ge contents in sphalerite.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107862"},"PeriodicalIF":3.4,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596065","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":"Tourmaline and monazite chemistry reflects magmatic-hydrothermal evolution of the Xianghualing W-Sn-Nb-Ta (Li, Be) pegmatite and metasomatite, South China","authors":"Wenbo Sun ,&nbsp;Huan Li ,&nbsp;Thomas J. Algeo ,&nbsp;Mohammed Abdalla Elsharif Ibrahim ,&nbsp;Nuerkanati Madayipu ,&nbsp;Xiaojun Hu ,&nbsp;Annan Guan ,&nbsp;Bowen Zhu","doi":"10.1016/j.gexplo.2025.107859","DOIUrl":"10.1016/j.gexplo.2025.107859","url":null,"abstract":"<div><div>The Nanling Metallogenic Belt, one of the world's largest rare-metal mineralization provinces, contains the Laiziling W-Sn-Nb-Ta rare-metal deposit. Despite its economic importance, the Li and Be mineralization and associated hydrothermal history of this deposit have not been studied in detail and remain controversial. This study presents the first in situ U<img>Pb dating and Nd isotopic analysis of monazites, as well as chemical composition and B isotopic data of tourmalines, from Laiziling pegmatites and metasomatites. LA-ICP-MS U<img>Pb geochronology yields crystallization ages of 152.0 ± 1.1 Ma for magmatic monazite and 151.9 ± 3.0 Ma and 151.2 ± 2.1 Ma for hydrothermal monazites. These results indicate that the hydrothermal stage was synchronous with pegmatite emplacement, and that pegmatite crystallization was related to hydrothermal activity. Variable Eu anomalies in monazite suggest an increase in environmental oxygen fugacity during the hydrothermal stage. The εNd(t) values of magmatic monazite (−7.49 to −6.82) are slightly lower than those of altered monazite (−7.24 to −6.51), indicating a slight disturbance of the Nd isotopic system by hydrothermal processes. The tourmalines exhibit oscillatory zoning from core to rim (Tur-I to Tur-VI) with δ¹¹B values ranging from −13.6 to −11.7 ‰. This observation suggests that tourmaline was derived from a single continental crustal source. The δ¹¹B of tourmaline shows a gradual decrease from cores to rims. The variation in B isotopes and chemical composition of tourmaline may be related to the mixed of the original igneous components in the earlier stage of metasomatism. LA-ICP-MS mapping of the cross and longitudinal sections of tourmaline shows elemental variations during its crystallization, with Tur-IV used as an indicator of magma evolution into the hydrothermal stage. After entering the hydrothermal stage, exchange vectors gradually changed from □Al(NaMg)₋₁ to MgFe₋₁, with the tourmaline type transitioned from schorl to Mg-foitite. Although rare metal mineralization and pegmatite emplacement were synchronous, the multiple stages of magma evolution exhibit differences in mineralization. The mineralization of Nb<img>Ta during the magmatic period has been confirmed previously. Principal component analysis (PCA) was used to predict the geochemical behavior of Li-Be-W-Sn and to determine the chemical controls on tourmaline crystallization at different stages of magmatic evolution. Enrichment and precipitation of Li usually occur during the magmatic stage, while Be-W-Sn mineralization is typically related to late hydrothermal alteration. However, the Laiziling deposit is characterized by Li mineralization synchronously with pegmatite emplacement, and by Be-W-Sn mineralization with hydrothermal alteration after this emplacement event. Our findings provide new insights into the formation processes of rare-metal mineral deposits.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107859"},"PeriodicalIF":3.4,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572791","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":"Unveiling predominant and latent factors influencing the geochemical variability in a river catchment: A statistical and visual approach","authors":"Salvatore Dominech ,&nbsp;Shouye Yang ,&nbsp;Annalise Guarino ,&nbsp;Antonio Iannone ,&nbsp;Antonio Aruta ,&nbsp;Stefano Albanese","doi":"10.1016/j.gexplo.2025.107858","DOIUrl":"10.1016/j.gexplo.2025.107858","url":null,"abstract":"<div><div>The Sabato River catchment basin in Southern Italy was investigated to assess and understand geochemical variations affecting potentially toxic elements along its course. For this purpose, thirty-five stream sediment samples were collected in the fall of 2018 from the river's main course. The individual composition found at each collection point was associated with the relative sample catchment basin (SCB) before undergoing a compositional data analysis (CoDA). Both raw and centred log-ratio (clr) transformed data were plotted against sediment granulometric and basin morphological features to reveal any dependence of geochemistry on landforms and catchment hydrodynamic settings. Geochemical Upper Baseline Limits (UBLs) were estimated for the basin, using raw data to discriminate local anomalies. In contrast, clr-data were compared with a proposed anomaly threshold (AT) for the same purpose.</div><div>A Robust Principal Factor Analysis (RPFA) was conducted on the clr-transformed data to identify natural and anthropogenic processes influencing the sediments of the Sabato River. The RPFA revealed that the predominant geochemical processes in the studied catchment basin were natural, with the weathering of pyroclastic covers and variations in grain size as key factors. The compositional balance technique, based on isometric log-ratio (ilr), was used to explore the results and emphasise one factor's predominance over another. A new thematic map, “Rainbow map”, was finally proposed to show the spatial dominance of one process over the others or their concurrent co-dominance.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107858"},"PeriodicalIF":3.4,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563213","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":"Human health risk assessment of toxic metal(loid)s in soils and crops around a PbZn mine, Central Iran: Implications of human bioaccessibility and bioavailability to crops","authors":"Giti Forghani Tehrani ,&nbsp;David A. Rubinos ,&nbsp;Afshin Qishlaqi ,&nbsp;Margaret C. Graham","doi":"10.1016/j.gexplo.2025.107855","DOIUrl":"10.1016/j.gexplo.2025.107855","url":null,"abstract":"<div><div>This study evaluates the pollution and human health risks due to the potentially toxic elements (PTEs) As, Cd, Pb and Zn occurrence in soils and crops (<em>Capsicum annum, Raphanus sativus</em>, <em>Lepidium sativum,</em> and <em>Cucumis sativus</em>) in the vicinity of an important Pb<img>Zn mine (Irankuh) in Central Iran. To these aims, the total, crops bioavailable and human bioaccessible concentrations of these PTEs in the soils (<em>n</em> = 75) and their total concentrations in edible parts of selected crops (<em>n</em> = 14), were analyzed and related with potential human health risks. Non-carcinogenic and carcinogenic risks (NCR and CR) of PTEs in the soils and crops were assessed by the USEPA's human health risk assessment (HHRA) method, through both deterministic and probabilistic (Monte Carlo simulation, MCS) approaches. Anomalous accumulation of total As, Cd, Pb and Zn in the soils collected near the mining site was found, though the crops bioavailable concentrations of the elements in the soils and their contents in crops followed the order As &gt; Pb &gt; Cd &gt; Zn. The HHRA outcomes based on soil's total element concentrations showed that, for the three routes of exposure −ingestion, dermal contact and inhalation− and any considered PTE, the average NCR Hazard Quotient (HQ_total) for children is higher (4–8 times through ingestion, 2 times through dermal contact, and 1.5 times through inhalation) than for adults. While Pb has the highest HQ_total for children and adults through ingestion and dermal contact, Cd has the highest HQ_total values through the inhalation route. The concentrations of As and Cd in soils pose a CR for children through the ingestion route. Even though HHRA based on human bioaccessible PTEs concentrations yielded much lower risk indexes, it indicates that there is NCR due to Pb and CR by As and Cd for children through ingestion route. Crop analysis revealed that Cd, As, and Zn have the highest Transfer Factor (TF) and Estimated Daily Intake (EDI) in <em>Lepidium sativum,</em> while the maximum TF and EDI for Pb were recorded in <em>Raphanus sativus.</em> The total HQ (THQ) for children is &gt;1 for Pb, indicating that the consumption of contaminated crops must be considered as a major threat to that age group. Likewise, the CR of As (for children) and Cd (for adults and children) by consuming crops from the study area is probable. The results of the study emphasize on the necessity of considering the human bioaccessible and crop bioavailable contents of pollutants in mining areas to obtain a more accurate evaluation of the possible health risks and protect local communities.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107855"},"PeriodicalIF":3.4,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570302","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":"Geochemistry and genesis of skarn-related tungsten mineralization of the Salau Deposit, Pyrenean Axial Zone","authors":"Eric Gonzalez ,&nbsp;Huan Li","doi":"10.1016/j.gexplo.2025.107853","DOIUrl":"10.1016/j.gexplo.2025.107853","url":null,"abstract":"<div><div>This study investigates the trace element chemistry of scheelite and sulfides (chalcopyrite, arsenopyrite, pyrrhotite) from the reduced skarn Salau deposit, one of France's largest tungsten deposits, located in the Pyrenean Axial Zone, to unravel the interplay between Variscan granodiorite intrusion, fluid composition and evolution, and metal transport during deposit formation. Cathodoluminescence imaging and geochemical data identify multiple scheelite generations corresponding to different mineralization stages: an early-stage, high-temperature type (GB Sch I) characterized by negative Eu anomalies, and a later retrograde type (GB Sch II) with positive Eu anomalies, both exhibiting internally variable but globally low Mo content characteristic of reduced skarn. A third, late-stage scheelite generation (GD), influenced by Veronique Fault-derived fluids, exhibits LREE depletion and near absent Mo concentrations (&lt;2 ppm), forming in association with sulfide-rich mineralization (arsenopyrite: As &lt;51 wt%, Bi &lt;483 ppm; pyrrhotite: Co/Ni &gt;5).</div><div>Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of scheelite and sulfides provide new insights into fluid evolution and trace element partitioning in the Salau skarn system. Scheelite displays distinct trace element variations, with early-stage crystals (GB Sch I) characterized by a relatively higher Mo (though &lt;0.1 wt%) and negative Eu anomalies, while later scheelite generations (GB Sch II, GD) exhibit evolving REE patterns and elemental enrichments linked to fluid chemistry changes. Sulfides, including chalcopyrite, arsenopyrite, and pyrrhotite, show compositional differences that reflect variations in sulfur activity and metal transport mechanisms.</div><div>Trace element systematics (e.g., Sr²⁺, Mo⁶⁺, REEs) indicate a transition from high-temperature magmatic-hydrothermal fluids to lower-temperature, sulfur-rich hydrothermal phases. Under sustained reduced conditions, with Y/Ho correlations suggesting minimal fluid mixing. Geochemical signatures primarily reflect fluid evolution within this reduced skarn framework, recording progressive changes in temperature, salinity, and redox conditions.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107853"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522851","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":"Geochemical sampling in Kaustinen, Finland – Indications of new lithium sources","authors":"Seppo Leinonen ,&nbsp;Jussi Pokki","doi":"10.1016/j.gexplo.2025.107856","DOIUrl":"10.1016/j.gexplo.2025.107856","url":null,"abstract":"<div><div>Indications of undiscovered lithium resources in the Kaustinen region of Finland were investigated through bedrock and till sampling using percussion drilling. The area belongs to the Paleoproterozoic Ostrobothnia Schist Belt, till deposition was in the Quaternary Period. Local spodumene pegmatites are classified as lithium‑cesium‑tantalum (LCT) pegmatites, particularly albite-spodumene types. Sampling in Leviäkangas area covered 2175 m along 11 lines, samples every 25 m. The targets were selected to cross some of the previously mapped spodumene boulder fans. Total of 98 rock-chip and 139 till samples were analyzed using ICP-MS and ICP-OES methods, with four-acid and aqua regia dissolutions. Elevated lithium &gt;143 mg/kg as twice the background was identified in 30 rock-chip samples (150–527 mg/kg). Metasediments were visually identified as mica schist. Granite discoveries, a lithium rich (Li 350 mg/kg) and a lithium-poor type (Li 40), displayed LCT characteristics based on Mg/Li, K/Rb, and Nb/Ta ratios. Halos, enriched in Li, Be, Nb, Rb and Sn extended 25–75 m around granites, while lithium-enriched tills reached several hundred meters. Bottom tills contained 20–161 mg/kg Li (four-acid leaching), while surface tills ranged 17–109. Tills from excavator made pits contained spodumene in heavy mineral studies. Glacial flows have been from NE (040°) or NW (340°). The geochemistry of metasediments showed indications of undiscovered Li deposits, while the utilization of till samples in mapping Li-enriched halos would have required a more comprehensive knowledge of stratigraphy and glacial flow directions.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107856"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522850","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":"Investigating the spatial heterogeneity impact on the geochemical and mineralogical controlling factors framing acid generation at a closed tailings facility","authors":"Abdellatif Elghali ,&nbsp;Karim Samra ,&nbsp;Youssef Toubri ,&nbsp;Thomas Genty ,&nbsp;Mostafa Benzaazoua","doi":"10.1016/j.gexplo.2025.107852","DOIUrl":"10.1016/j.gexplo.2025.107852","url":null,"abstract":"<div><div>Mineral industry is increasingly generating massive amounts of tailings, usually deposited in tailings storage facilities (TSF). To highlight the spatial variability effect on the geoenvironmental outcomes, five samples were collected from a closed TSF from different locations. The characterization findings were used to investigate the heterogeneous physical, geochemical, and mineralogical properties depending on the sample location. For instance, the pyrite content spans the interval between 0.02 and 8 wt%. Likewise, the carbonate content varies from 0.05 wt% to 43 wt%. Static tests performed to assess the potential of acid generation yielded various findings regarding the acid generation potential. Therefore, each static test should be interpreted without overlooking its limitations and the mineralogical implications under the test operating conditions. Hence, a thorough mineralogical characterization was undertaken for the selected samples to highlight their inherent mineralogical differences. Additionally, kinetic testing using weathering cell tests, highlighted that the samples C1 and C2 are acid generating, whereas C3, C4 and C5 maintain circumneutral to alkaline pH throughout the testing period. Iron release was negligible for the samples C2, C3, C4 and C5 due to its precipitation as secondary iron-oxyhydroxides that coated pyrite in circumneutral conditions. A kinetic model was established using PHREEQC to perform a parametric analysis regarding the neutralization lag time of silicates as well as the effect of calcite depletion on iron and sulfate release. The main outcome of the model underline that at least 20 wt% albite should be included in a calcite-based amendment to prevent iron release upon calcite depletion or passivation.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107852"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518315","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}