Journal of Geochemical Exploration最新文献

{"title":"Comment on “Spatial distributions, potential sources, and ecological risks of heavy metals in stream sediments of Zambia” by Sun et al. (2025)","authors":"Ondra Sracek , Bohdan Kříbek , Vojtěch Ettler , Martin Mihaljevič , Aleš Vaněk , Imasiku Nyambe","doi":"10.1016/j.gexplo.2025.107791","DOIUrl":"10.1016/j.gexplo.2025.107791","url":null,"abstract":"","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107791"},"PeriodicalIF":3.4,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883231","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":"Distribution and fractionation of Rare Earths (LaLu, Sc, Y) and other critical metals in bauxite residues: addressing the profitability of the red muds stored at the Porto Vesme disposal site, Sardinia Island, Italy","authors":"Paola Mameli ,&nbsp;Emanuela Schingaro ,&nbsp;Ernesto Mesto ,&nbsp;Maria Lacalamita ,&nbsp;Abdelhamid Ouladmansour ,&nbsp;Guido Cerri ,&nbsp;Alfredo Idini ,&nbsp;Carmine Cisullo ,&nbsp;Giovanni Mongelli","doi":"10.1016/j.gexplo.2025.107792","DOIUrl":"10.1016/j.gexplo.2025.107792","url":null,"abstract":"<div><div>In southern Sardinia, Italy, at the Porto Vesme disposal site, about 30 million tonnes of bauxite residues deriving from Al extraction through the Bayer process are stored.The mineralogical composition includes hematite, goethite, ilmenite, gibbsite, boehmite, bayerite, anatase, rutile, quartz, sodalite, cancrinite, andradite, calcite, dolomite, halite. Lanthanides-rich phosphate minerals as well as LREE ferrotitanates were sporadically observed.</div><div>The samples chemistry provides Fe₂O₃, Al₂O3, SiO₂, Na₂O, TiO₂ and CaO in order of abundance. The REEs are enriched relative to the parent material with LREEs &gt; HREEs+Y and Sc. Ce is the most abundant LREE and the chondrite normalized patterns show significant positive Ce anomalies.</div><div>The inter-elemental relationships among major, minor and trace elements were evaluated by R-mode factor analysis. The first factor accounts for most of the variance (52.1 %) of the dataset and explains the competition between the desilication and relict + neoformed phases with the latter hosting the LREEs and other critical metals. The second factor (variance = 15.2 %) represents the control exerted by the mineral zircon on the distribution of HREEs+Y.</div><div>The HREEs+Y are enriched relative to the average Upper Continental Crust along with other critical metals such as Hf, TiO₂ and W. In addition, a set of profitability indices, including the ratio (Nd + Dy+Ce + Pr + La)/Σ(REEs+Y), specifically addressed to the electromobility market, suggest an overall significant economic potential for the bauxite residues stored at the Porto Vesme site.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107792"},"PeriodicalIF":3.4,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887326","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":"Magmatic and hydrothermal evolution of the Weilasituo Sn polymetallic deposit recorded by the Li and O isotope compositions of zinnwaldite","authors":"Ruizhe Shi ,&nbsp;Junxing Zhao ,&nbsp;Rolf L. Romer ,&nbsp;Zhenzhen Li ,&nbsp;Kezhang Qin","doi":"10.1016/j.gexplo.2025.107790","DOIUrl":"10.1016/j.gexplo.2025.107790","url":null,"abstract":"<div><div>Lithium and O isotopic compositions of zinnwaldite from magmatic (cassiterite), magmatic-hydrothermal transition (UST) and hydrothermal (tin‑tungsten, molybdenum and copper‑zinc) stages of the Weilasituo Sn polymetallic deposit and fluid inclusions in quartz are used to trace the magmatic-hydrothermal evolution. Fluid inclusion microthermometry and laser Raman analysis indicate that the H₂O-NaCl-CO₂-CH₄ fluids associated with the Weilasituo deposit have high to medium-high temperatures and moderate salinities. The δ⁷Li values of magmatic zinnwaldite decrease with magmatic differentiation, which cannot be explained by fractional crystallization alone and, therefore, reflect late-stage fluid exsolution. Lithium and O isotope fractionation during fluid evolution depends not only on the temperature, but also on fluid-rock reactions that affect the Li and O isotopic compositions of the fluids from the hydrothermal tin‑tungsten stage and liquid-vapor phase separations that decrease δ⁷Li and increase δ¹⁸O of the fluids from the copper‑zinc stage.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107790"},"PeriodicalIF":3.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899221","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 prediction research using the Geology-based Cyclic Adversarial Network for Anomaly Detection","authors":"Long Tang ,&nbsp;Bin Liu ,&nbsp;Tonghui Luo ,&nbsp;Zhongli Zhou ,&nbsp;Xiaoyu Zhang","doi":"10.1016/j.gexplo.2025.107789","DOIUrl":"10.1016/j.gexplo.2025.107789","url":null,"abstract":"<div><div>Deep learning algorithms represented by generative adversarial networks (GANs) have been extensively applied in mineral prospectivity mapping research. However, the inherent instability and “black-box” nature of these models have constrained further advancement in such studies. This research proposes an anomaly detection model integrating geochemical data with geological knowledge (Geology-based Cyclic Adversarial Network for Anomaly Detection, G-CANomaly). First, taking the Mila Mountain area of Tibet as the study area, we quantified the relationship between deposit density and ore-controlling factors (fault structures) using multifractal singularity theory. Second, we restructured the network architecture of traditional GANomaly models and embedded geological knowledge to establish the G-CANomaly anomaly detection model, achieving a transition from purely data-driven approaches to hybrid “data + knowledge”-driven methodologies. Finally, we conducted comparative analyses of model performance among GANomaly, CANomaly, and G-CANomaly. The results demonstrate that: (1) The anomaly zones delineated by G-CANomaly exhibit the highest spatial correlation with known mineral occurrences in the study area. (2) The top 3 % anomaly areas can encompass 80 % of known mineral deposits. (3) The main assessment metrics of G-CANomaly, AUC, Accuracy, and Recall, were 0.97, 0.89, and 0.93, showing 3–6 % improvements over baseline models. These findings indicate that the G-CANomaly model demonstrates strong feasibility in geochemical anomaly identification research, with notably enhanced training stability and convergence rate. This study provides valuable references for constructing hybrid geochemical-geological knowledge-driven deep learning models and enriches the methodological framework of mineral prospectivity mapping.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107789"},"PeriodicalIF":3.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859580","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":"An integrated singularity–energy analysis to reveal mineralization-related geochemical patterns","authors":"Saeid Esmaeiloghli ,&nbsp;Mahyar Yousefi","doi":"10.1016/j.gexplo.2025.107788","DOIUrl":"10.1016/j.gexplo.2025.107788","url":null,"abstract":"<div><div>During the last two decades, local singularity analysis (LSA) has become a leading technique to enhance weak geochemical anomalies associated with non-linear ore-forming processes operating in complex Earth systems. Singularity maps of multiple ore-forming elements are preferably synthesized to reveal multi-element geochemical anomalies and to portray them as stronger mineralization-related geochemical signatures. In this regard, classifying anomalous components is crucial to identify different patterns of ore formation-related geochemical anomalies, a step forward to delimit target areas for metal exploration. This research puts forward an integrated singularity–energy (S–E) analysis dealing with the variety in the metal enrichment patterns obtained from singularity mapping of multiple ore-forming elements. As per the S–E methodology, the LSA is applied to the rasterized geochemical maps with the aim of reducing the adverse effects of overburden and enhancing weak geochemical anomalies. Relying on multi-sample energy statistics, a <em>k</em>-groups partitioning based on energy distance is then devised to classify singularity maps into <span><math><mi>k</mi></math></span> patterns with contrasting probability distributions, thereby recognizing different patterns of multi-element geochemical anomalies. Eventually, prospectivity indices for the resulting S–E patterns are calculated to prioritize mineralization-related patterns and to automate the definition of exploration targets. The potential application of the S–E analysis is demonstrated by a stream sediment geochemical dataset (viz. Cu, Au, Pb, and Zn) pertaining to the Moalleman district, NE Iran. Moreover, additional geochemical patterns are recognized by concentration–area multifractal modeling of additive geochemical indices and by <em>k</em>-means clustering of singularity maps of ore-forming elements, serving as traditional references to constitute comparative analyses. Appraisal by success-rate curves indicates that metal enrichment patterns derived from S–E analysis, compared to those from traditional approaches, establish a more significant spatial conformity with hydrothermal- and epithermal-type mineralization events within the study area. The findings suggest that the proposed technique has robust properties to bring more efficient exploration knowledge and reliable evidence for prospecting buried and covered metal deposits within complex Earth systems.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107788"},"PeriodicalIF":3.4,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844105","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 of sulfides from massive carbonate replacement type tin ore at Gaofeng, Dachang orefield: Insights into precipitation conditions and enrichment of critical metals","authors":"Yu-Pei Liu ,&nbsp;Pei Ni ,&nbsp;Jun-Yi Pan ,&nbsp;Wen-Chao Su ,&nbsp;Stefano Albanese ,&nbsp;Jian-Ming Cui ,&nbsp;Yuan-Feng Cai ,&nbsp;Ming-Sen Fan ,&nbsp;Zhi-Lin Cheng","doi":"10.1016/j.gexplo.2025.107787","DOIUrl":"10.1016/j.gexplo.2025.107787","url":null,"abstract":"<div><div>Sulfide ore minerals are significant carriers of multiple critical metals, thereby highlighting the importance of evaluating the exploration potential in sulfide-rich deposits. Tin-bearing sulfide ores from the carbonate replacement type tin deposits (cassiterite-sulfide type) generally contain substantial reserves of critical metals as by-products. This study analyzes the major and trace elements compositions of marmatite, arsenopyrite, pyrrhotite, and jamesonite from the Gaofeng deposit using EPMA and LA-ICP-MS. The Gaofeng Sn-polymetallic deposit, situated in the Dachang orefield, the Youjiang Basin, is a typical sulfide-rich carbonate replacement type tin deposit with reserves of 0.23 Mt. Sn, 0.65 Mt. Sb, 1.50 Mt. Zn, 0.79 Mt. Pb, 2800 t Ag and 2000 t In. The No. 100 ore body, hosted within Middle Devonian reef limestone, is intruded by the post-ore granite porphyry dyke. The sulfides account for over 90 wt% of the ore, mainly including marmatite, pyrrhotite, arsenopyrite, and jamesonite. LA-ICP-MS analysis and principal component analysis (PCA) results show that trace element concentrations in sulfides generally exhibit strong spatial consistency and no significant correlation with the horizontal distribution. The spatial uniformity of trace element distribution in sulfides indicates the precipitation rate of each sulfide is relatively high throughout the ore body, and the granite porphyry is closely related to the undiscovered ore-forming granite batholith without a direct role in the ore-forming process. Marmatite is characterized by exploitable enrichment of Cd (5479 ppm) and In (604 ppm), with dominant substitution mechanisms of Zn²⁺ ↔ (Fe²⁺, Mn²⁺, Cd²⁺) and 2Zn²⁺ ↔ In³⁺ + Cu⁺. The Sn content in jamesonite is notably high, ranging from 222 to 4315 ppm (average: 814 ppm), with Sn incorporated via 2Sb³⁺ + Fe²⁺ ↔ 2Sn⁴⁺ + □ and 2Sb³⁺ + □ ↔ Sn⁴⁺ + 2(Ag⁺, Cu⁺). The mineralization temperatures are estimated as 353–372 °C for arsenopyrite, 254–~350 °C for hexagonal pyrrhotite, 329 ± 26 °C for marmatite, and &lt; ~180 °C for monoclinic pyrrhotite, indicating fluid cooling is the key precipitation mechanism for sulfides. The co-precipitation of cassiterite and arsenopyrite is likely controlled by fluid cooling and redox reaction of 3SnCl₂ + 2H₃AsO₃ + 2FeCl₂ + 2H₂S = 3SnO₂ + 2FeAsS +10H⁺ + 10Cl⁻. High mineralization temperature and the “indium window” effect are the dominant controls on indium enrichment in marmatite/sphalerite from carbonate replacement-type tin deposits. Jamesonite shows a tremendous potential for Sn extraction as by-product, where Sn may source from the partial reactivation of the early precipitated cassiterite.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107787"},"PeriodicalIF":3.4,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844104","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":"Mineralogy, geochemistry, and petrogenesis of iron oxide-apatite ores in the Bafq mining district, Central Iran: Proposed a new tectonic setting for mineralization","authors":"Foroogh Zolala ,&nbsp;Masood Alipour-Asll ,&nbsp;Mahmood Sadeghian ,&nbsp;Habibollah Ghasemi ,&nbsp;Mingguo Zhai ,&nbsp;Erfan Amidimehr","doi":"10.1016/j.gexplo.2025.107785","DOIUrl":"10.1016/j.gexplo.2025.107785","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Posht-e-Badam block (PBB), as a part of the Central Iran microcontinent zone, hosts many large Kiruna-type iron oxide-apatite (IOA) deposits. The Late Neoproterozoic–Early Cambrian volcano-sedimentary sequence of the Rizu series hosts intrusive rocks and IOA mineralization. The ore occurrences are observed as stratiform and epigenetic forms in the Bafq region. Stratiform Fe&lt;img&gt;Mn oxide ores are commonly associated with brownish dolomite layers, or is intercalated with jaspilite in association with submarine basaltic lava flows and tuffaceous shale formed by direct precipitation from the ore-forming fluids during submarine exhalative/or submarine volcano-sedimentary processes on the seafloor. Epigenetic IOA ores occurred as massive, lenses, vein-veinlets, and brecciated forms in the metasomatic host rocks. Various generations of magnetite and apatite are observed in IOA ores in this region. Magmatic generation of magnetite (Mag 1) and apatite (Ap 1) comprises &gt;95 vol% of the massive and lenses ores. Hydrothermal generations of magnetite (Mag 2 and Mag 3) and apatite (Ap 2, Ap 3, and Ap 4) are as vein-veinlets, open space-fillings and brecciated forms, and accompanied by actinolite, hematite, calcite, and quartz. Hydrothermal alterations associated with the IOA ore deposits in the Bafq region include sodic, actinolitic, sericitic, argillic, silicic, and carbonatization. All of these alteration types resulted from intrusion of alkaline magmatic bodies into the Rizu series in an extensional regime (rift setting) governing the area. Based on magnetite and apatite contents, the Bafq deposits are classified into magnetite-rich, magnetite-apatite, and apatite-rich deposits. Enrichment of LREE relative to the HREE and the strong negative Eu anomaly are the important geochemical signatures of the Bafq IOA deposits. Also, geochemical data shows that the all samples from the IOA deposits in the Bafq region fall into the field of the Kiruna-type IOA deposits. The δ&lt;sup&gt;18&lt;/sup&gt;O values of most minerals (+1.1 to +7.6 ‰) represent the magmatic-hydrothermal (δ&lt;sup&gt;18&lt;/sup&gt;O &gt; +0.9 ‰) process, while δ&lt;sup&gt;18&lt;/sup&gt;O values below +0.9 ‰ indicate a low-temperature hydrothermal alteration and a degree of secondary oxidation process. Comparing the ages of igneous rocks and mineralization shows the genetic association of primary iron oxide-apatite deposits (~543 to 490 Ma) with co-magmatic gabbro, diorite, quartz diorite and granites (~547 to 525 Ma), while the secondary dark apatites and monazites (~440 and 437 Ma) are correlated with syenite intrusions in the Late Ordovician-Early Silurian (~452 to 430 Ma). These events are consistent with magmatism and sedimentation in a regionally extension and basin development in the Late Neoproterozoic-Early Cambrian to Silurian in the Bafq region. Our results suggest that the Bafq IOA mineralization formed in a post collisional extensional rift setting resulting from relaxation and then extension of the cen","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107785"},"PeriodicalIF":3.4,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834247","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":"Occurrence, Distribution and Ecological Health Risk Assessment of Heavy Metals Through Consumption of Drinking Water in Urban, Industrial, and Mining Areas of Semi − Arid to Humid Subtropical Areas","authors":"Irfan Ullah ,&nbsp;Muhammad Adnan ,&nbsp;Javed Nawab ,&nbsp;Irfan Safi ,&nbsp;Sardar Khan","doi":"10.1016/j.gexplo.2025.107786","DOIUrl":"10.1016/j.gexplo.2025.107786","url":null,"abstract":"<div><div>The current study assessed ecological and human health risks associated with heavy metals (HMs) consumption via drinking water from urban, industrial, and mining areas across semi-arid to humid subtropical areas of Pakistan. A total of 180 water samples were collected and analyzed. The physical parameters including pH, electrical conductivity, nitrates, carbonates, and total soluble salts remained within thepermissible limits. However, the average concentrations of cadmium (Cd), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) surpassed World Health Organization (WHO) guidelines, with ranges from 1.45–14.5, 3.75–15.8, 11.5–44.3, 4.12–33.2, 0.95–15.8, 0.85–14.9, and 0.35–10.9 mg.L^–1, respectively. Contamination factor (CF) analysis indicated highest pollution levels from Cd, while pollution load index (PLI) values were &gt; 1 across all sites, confirming significant HM pollution. Further, ecological risk assessment (ERA) showed varying levels of ecological risk, from low to high, associated with HM exposure. Average daily intake (ADI) of HMs was remarkably higher in children than adults. Health hazard quotient (HQ) values for Cd (2.9E+03–1.8E+04) and Pb (1.6E+00–3.8E+01), along with hazard indices (HI), indicated non-carcinogenic health risks. Moreover, carcinogenic risk (CR) exceeded threshold (CR &gt; 1.0E−06) for Pb at all sites, with Cr and Ni posing risks at numerous sites. Statistical analyses, including principal component analysis (PCA) and pearson’s correlation, revealed significant correlations (p&lt;0.05) among several HMs. Effective treatment of drinking water is essential to mitigate the health and ecological risks associated with HMs contamination in the study area.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107786"},"PeriodicalIF":3.4,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828620","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":"Ore genesis and critical metal enrichment using deep learning algorithms in Gunga Pb-Zn deposit, Southern Pakistan: Constraints from sphalerite geochemistry and isotopic compositions","authors":"Muhammad A. Gul ,&nbsp;Huishan Zhang ,&nbsp;Yu Yang ,&nbsp;Guangli Ren ,&nbsp;Chao Sun ,&nbsp;Xiaojian Zhao ,&nbsp;Tahir Bin Yousuf ,&nbsp;Ahmed Shah ,&nbsp;Rizwan Sarwar Awan ,&nbsp;Mohamed Faisal ,&nbsp;Xiaoyong Yang","doi":"10.1016/j.gexplo.2025.107771","DOIUrl":"10.1016/j.gexplo.2025.107771","url":null,"abstract":"<div><div>The Kirthar Fold and Thrust Belt in southern Pakistan is widely recognized as a major metallogenic province owing to the extensive presence of Pb-Zn deposits within the Jurassic sedimentary shelf sequence. One of these deposits, the Gunga Pb-Zn deposit, is a significant economic ore deposit situated within the Anjira Formation and comprises two mineralization zones, the Upper Mineralization Zone (UMZ) and Lower Mineralization Zone (LMZ). Despite the scarcity of documentation on the metallogenic source, origin, mineralization temperature, and other physicochemical conditions, our research is the first to explore the metallogenic differentiation and ore genesis of the deposit by examining minor and trace elements in sphalerite and isotopic analyses (S-Pb). The Gunga Pb-Zn deposit, amounting to 6.86 Mt. with 2.1 % and 11.4 % Pb and Zn, respectively, is linked to the interbedded limestone and shale unit of the Anjira Formation, and approximately below the depth of 200–250 m of the Jurassic-Cretaceous contact, the mineralization is believed to occur in the upper section of the Formation. Sphalerite is the dominant ore mineral, galena is a subordinate mineral, and pyrite is present in the main ore minerals. Sphalerite in the LMZ was found in a vein style, whereas it was disseminated in the UMZ and enriched in (medians) Ge (166 ppm), Cd (541 ppm), Pb (139 ppm), Ag (42 ppm), and Hg (68 ppm), lacking In (0.17 ppm), Co (6 ppm), and Mn (19). Based on trace element concentrations, the LMZ has a reduced environment, higher sulfur fugacity, and higher mineralization temperature (180–200 °C) than the UMZ, which has a lower mineralization temperature (130–180 °C). The presence of black shales, low temperatures, and high sulfur fugacity are the key parameters for Ge enrichment in the Gunga deposit. The δ³⁴S values range from −10 to +5.6 ‰, suggesting that reduced sulfur was produced by both the BSR and TSR mechanisms, with basinal brines and seawater being the main sources of sulfur. The Pb isotope results suggest that the upper crust is the main source of the metals. In this study, Deep Learning algorithms based on sphalerite trace elements were employed for metallogenic discrimination of Pb-Zn deposits. The classifiers were trained on a dataset comprising approximately 3800 data points from 99 mineral deposits with published trace element compositions. The performance of the classifiers was assessed using a cross-validation with a k-fold variant. This study employed well-established classifiers on newly acquired geochemical data obtained from sphalerite samples collected from the Gunga Pb-Zn deposit. Based on the findings of this study, low temperature, lack of magmatic source elements, and clastic sedimentary sequence in a passive margin environment, a CD-type mineralization is proposed for the Gunga Pb-Zn deposit.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107771"},"PeriodicalIF":3.4,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874628","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":"Identifying key uranium sources in mine water: Open pit wall rock leaching and groundwater contributions in Leveäniemi open pit","authors":"Vimbainashe L. Dzimbanhete ,&nbsp;Oscar Paulsson ,&nbsp;Torbjörn Karlsson ,&nbsp;Lena Alakangas ,&nbsp;Olof Martinsson","doi":"10.1016/j.gexplo.2025.107773","DOIUrl":"10.1016/j.gexplo.2025.107773","url":null,"abstract":"<div><div>Uranium (U) release from mining is an environmental concern due to U's chemical toxicity and radioactivity. In Sweden, U is classified as a river basin-specific pollutant (RBSP), emphasizing the need to minimize its release from mining activities. This study aims to trace the sources of U contributing to elevated concentrations in mine water from Leveäniemi open pit, Northern Sweden, to inform point-source prevention measures to mitigate U release. The study investigates U leaching rates from key rock types forming the open pit walls and evaluates groundwater entering the open pit through drainage pipes and fractures as a potential source of U. Minewall weathering stations showed higher U leaching rates from pegmatites compared to other rock types. The pegmatite station where uraninite was the predominant mineral had a leaching rate averaging 1800 μg/m²/wk, compared to 430 μg/m²/wk at the station where pyrochlore was the predominant U mineral and uraninite occurred as inclusions in pyrochlore. However, pegmatites cover a small area of the exposed surface in the open pit compared to trachyandesite, which leached at a lower average rate of 30 μg/m²/wk. Groundwater entering the open pit through fractures and drainage pipes was also identified as a significant source of U in the mine water, further influencing mine water U concentrations. Careful handling of pegmatite-containing waste rock is essential to prevent increased U leaching in both the open pit and waste rock dumps. This study highlights the importance of identifying rocks with high U release potential before exposure during mining. Additionally, understanding the distribution of these high U-release rock types along groundwater flow paths can also help to predict groundwater U concentrations and inform site-specific management strategies to mitigate U contamination in downstream recipients.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"275 ","pages":"Article 107773"},"PeriodicalIF":3.4,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828619","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}