Journal of Geochemical Exploration最新文献

{"title":"Soil anomaly mapping in the Hattfjelldal area, Norway: Reconciling soil geochemical and geophysical properties within their spatial context","authors":"Pedro Acosta-Góngora ,&nbsp;Malin Andersson ,&nbsp;Terje Bjerkgård ,&nbsp;William A. Morris ,&nbsp;Tobias Kurz ,&nbsp;Madeline Lee ,&nbsp;Marie-Andre Dumais ,&nbsp;Aziz Nasuti ,&nbsp;Mikis van Boeckel ,&nbsp;Johannes Jakob ,&nbsp;Ana Carolina R. Miranda ,&nbsp;Aidian Crilly ,&nbsp;Ying Wang ,&nbsp;Behnam Sadeghi","doi":"10.1016/j.gexplo.2025.107911","DOIUrl":"10.1016/j.gexplo.2025.107911","url":null,"abstract":"<div><div>This study presents a multivariate framework for geochemical data processing and anomaly detection to support mineral exploration in the Hattfjelldal area, Norway. The workflow integrates data levelling, multivariate analysis, and spatial evaluation to improve the detection and interpretation of geochemical anomalies associated with volcanogenic massive sulfide (VMS) mineralization. Soil geochemical and magnetic susceptibility data were log-transformed and subsequently levelled using <em>Z</em>-score normalization by soil type and lithology. Both linear (principal component analysis, PCA) and non-linear algorithms (hierarchical clustering, isolation forest, and angle-based outlier detection) were applied to construct anomaly detection vectors. Hierarchical clustering proved particularly effective in defining element assemblages that refine anomaly detection, including associations of Type 1 (Ag, Mo, S, Sb, Bi, Pb); Type 2 A (Fe, Zn, Co, Mn) and Type 2B (Fe, Zn, Co, Mn, As, Cu). These groupings provide a robust geochemical and geological context within established VMS zoning models.</div><div>Magnetic susceptibility, although less reliable as a stand-alone exploration vector, enhances interpretation when integrated with geochemical anomalies. Fractal analysis applied to both, geochemical vectors and magnetic susceptibility data effectively distinguished background from anomalous values, delineating areas of potential economic interest. Spatial Feature Embeddings (SFE), derived from clustering radiometric, topographic, and spectral datasets, further improved the spatial characterization of anomalies. When combined with airborne magnetics, SFE enabled the refinement and prioritization of specific targets within broad anomaly zones.</div><div>Overall, this framework demonstrates the value of integrating statistical, geochemical, and geophysical methods within their spatial context, providing a transferable approach for exploration programs in Arctic environments.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107911"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362309","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":"Trace element and sulfur isotope constraints on the Genesis of Sb-(Au) deposits in Southern China: Insights from the Longkou deposit","authors":"Junwei Xu ,&nbsp;Xiangfa Song ,&nbsp;Degao Zhai ,&nbsp;Linyan Kang ,&nbsp;Xianghua Liu ,&nbsp;Kui Jiang ,&nbsp;Yulin Chen","doi":"10.1016/j.gexplo.2025.107892","DOIUrl":"10.1016/j.gexplo.2025.107892","url":null,"abstract":"<div><div>The Xiangzhong Metallogenic Province (XZMP) in southern China hosts the region's most extensive Sb-polymetallic mineralization system, comprising two principal deposit types: Sb-only and Sb–Au–(W). To investigate their genetic distinctions, we conducted in-situ LA-ICP-MS and sulfur isotope analyses on stibnite from the Longkou Sb<img>Au deposit in the Shaoyang Basin, and integrated these results with published data from the Xikuangshan, Daocaowan, Woxi, and Banxi deposits. Multivariate statistical analyses (PCA and PLS-DA) of stibnite trace elements reveal systematic geochemical differences between the two deposit types. Sb<img>Au deposits (e.g., Longkou, Woxi, Banxi) are enriched in Cu and Pb, whereas Sb-only deposits (e.g., Xikuangshan, Daocaowan) show elevated Hg and lower Cu<img>Pb concentrations. These patterns suggest that, while Sb in both deposit types was likely derived from Proterozoic basement rocks, metals such as Au, Cu, and Pb in Sb<img>Au deposits originated from deep magmatic-hydrothermal fluids. In contrast, ore-forming fluids in Sb-only systems were dominated by shallow-crustal or metamorphic sources, with limited magmatic input. The δ³⁴S values of stibnite are relatively uniform across most deposits, further supporting a shared sulfur source linked to basement lithologies. Trace element and sulfur isotope data point to two distinct mineralization mechanisms: in Sb<img>Au systems, magmatic-hydrothermal fluids transported metals from depth and leached Sb and S from basement rocks, while in Sb-only systems, magmatic activity primarily acted as a heat source, promoting the circulation of meteoric and metamorphic fluids that leached Sb and S from the basement. These findings provide a geochemical framework for distinguishing Sb deposit types and offer new insights into the metallogenic processes of Sb–(Au) systems in South China.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107892"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046588","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 Jurassic gold mineralization in southern Jiangxi Province, China: Fluid inclusions, H–O–S–Pb isotopic and Rb–Sr geochronological insights from the Liulong gold deposit","authors":"Tian-wen Chen ,&nbsp;Shi-jiong Han ,&nbsp;Yan-chen Yang ,&nbsp;Yu-xuan Liu ,&nbsp;Zhao-yang Song ,&nbsp;Zi-jian Zeng","doi":"10.1016/j.gexplo.2025.107919","DOIUrl":"10.1016/j.gexplo.2025.107919","url":null,"abstract":"<div><div>The Liulong gold deposit (5.7 t Au reserves @ 8.4 g/t), located in the eastern Nanling Metallogenetic Belt (NMB), represents the first medium-scale deposit discovered in the southern Jiangxi Province. Gold mineralization is predominantly hosted within Neoproterozoic Shangshi Formation metasedimentary tuffs and controlled by nearly NS-trending secondary fractures. The deposit comprises polymetallic sulfide-quartz veins and auriferous altered rocks, with four hydrothermal stages identified: (I) quartz-sericite-minor sulfide, (II) quartz-pyrite-arsenopyrite, (III) polymetallic sulfides‑gold minerals-quartz-siderite, and (IV) quartz-calcite. The Rb<img>Sr dating of pyrite and sphalerite yielded an isochron age of 156.7 ± 2.3 Ma (MSWD = 1.4), contemporaneous with ca. 163–157 Ma intermediate-acidic granitic intrusions near the mining district. The ore-forming fluids exhibit moderate to low temperatures, low salinity, and a H₂O–NaCl–CO₂ system containing variable CH₄ contents. From Stage II to Stage IV, the fluid inclusions (FIs) homogenized at temperatures of 308–370, 187–307, and 138–197 °C, respectively, with corresponding salinities of 1.9–6.2, 1.7–8.4, and 1.4–3.2 wt% NaCl equiv., respectively. Fluid boiling was the primary mechanism for the precipitation of gold and other metals. The δD_H2O values of FIs in quartz from different stages are relatively constant (−50.2 to −69.9 ‰), whereas calculated δ¹⁸O_H2O values show variation: 8.31–9.81 ‰ (Stage II), 3.65–4.85 ‰ (Stage III), and − 8.92 ‰ (Stage IV), respectively. These H<img>O isotope data suggest an initial magmatic fluids source, with meteoric water becoming dominant during the later mineralization stage. Sulfides exhibit narrow in situ δ³⁴S values (−0.85–2.00 ‰), yielding an estimated δ³⁴S value of −1.03 ‰ for the initial ore-forming fluids, calculated with the sulfur isotopic fractionation of pyrite–sphalerite pairs. Sulfide Pb isotopic ratios (²⁰⁶Pb/²⁰⁴Pb = 17.644–17.996, ²⁰⁷Pb/²⁰⁴Pb = 15.539–15.611, and ²⁰⁸Pb/²⁰⁴Pb = 38.176–38.413) differ from regional gold deposits in the NMB and plot between Yanshanian granites and Neoproterozoic ore-hosted strata rocks with a linear trend, indicating significant metal contributions from both Late Jurassic granites and Neoproterozoic strata. Therefore, the Liulong deposit is classified as a magmatic-hydrothermal gold deposit genetically linked to Late Jurassic intermediate-acidic granites, providing insights for exploring similar deposits in southern Jiangxi.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107919"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267208","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":"CNN inversion model considering texture features and its application to soil selenium content","authors":"Gong Cheng ,&nbsp;Xingwang Zhou ,&nbsp;Yuanyuan Tang ,&nbsp;Jin Chen ,&nbsp;Wenrui Yang ,&nbsp;Liangliang Dai ,&nbsp;Jia Liao ,&nbsp;Lingyi Liao","doi":"10.1016/j.gexplo.2025.107909","DOIUrl":"10.1016/j.gexplo.2025.107909","url":null,"abstract":"<div><div>Soil remote sensing geochemistry typically involves constructing inversion models by correlating geochemical data from samples with spectral data from remote sensing image pixels to infer soil element concentrations. However, the accuracy of modeling using only the emissivity of image element is low. Therefore, this paper incorporates texture information from the images as a modeling factor and constructs a Convolutional Neural Networks (CNN) inversion model that considers texture features, exploring the impact of texture features on the modeling process. Taking selenium (Se) as an example, the study first conducts a correlation analysis between the pretreatment remote sensing data and the soil sample chemical data to select the spectral bands with strong correlations. Then, based on these selected bands, the study uses a 17 × 17 grid of pixels surrounding the sample points as the input and the selenium content at the sample points as the output to construct the CNN inversion model. Finally, the inversion effect of CNN model is compared with Multiple Linear Regression (MLR), Support Vector Machines (SVM), Random Forests (RF) and Backpropagation Neural Networks (BPNN) models conducted by spectral feature alone or a combination of spectral and texture features. This comparison highlights the role of texture features in quantitative remote sensing modeling and the advantages of the CNN inversion model. The results show that compared to the best-performing model based on spectral features alone, SVM (with a test set R² = 0.286), the best model based on spectral and texture features, BPNN (with a test set R² = 0.377), improved the inversion accuracy by nearly 0.1. The CNN model achieved a test set R² of 0.504, significantly outperforming the other models. In conclusion, incorporating texture information into quantitative remote sensing modeling can effectively improve inversion accuracy, and the CNN model demonstrates a clear advantage in soil element inversion.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107909"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155535","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":"Large-scale polymetallic mineralization driven by long-lived magmatic-hydrothermal activity and subducted sediment influx: A case study from Toyoha, NE Japan","authors":"Mizuki Ishida ,&nbsp;Yuki Hieda ,&nbsp;Shuhei Araki ,&nbsp;Koichiro Fujinaga ,&nbsp;Toru Shimizu ,&nbsp;Masaharu Tanimizu ,&nbsp;Cindy Broderick ,&nbsp;Hitomi Nakamura ,&nbsp;Hikaru Iwamori ,&nbsp;Shiki Machida ,&nbsp;Shigekazu Yoneda ,&nbsp;Kentaro Nakamura ,&nbsp;Yasuhiro Kato","doi":"10.1016/j.gexplo.2025.107887","DOIUrl":"10.1016/j.gexplo.2025.107887","url":null,"abstract":"<div><div>Although there is increasing recognition that long-lived magmatic-hydrothermal systems are essential components of large-scale mineralization, relatively little is known about the source processes that enable such activity, especially in areas of average crustal thickness. To address this issue, we investigated the sources of ore-forming elements and drivers of prolonged ore-forming activity (&gt;1 million years) in the Toyoha polymetallic intermediate-sulfidation deposit, located at the northern end of the Northeast Japan Arc. We have presented Pb isotopic evidence that in the southeastern part of the deposit, where the hydrothermal activity lasted substantially longer (&gt;1 million years) than the nearby (&lt;10 km) volcanic activities, sulfide minerals from the ore had a specific metal source in addition to the wall rocks and the magmas observable as nearby extrusive rocks. The additional source was likely latent intrusions similar to the isotopically enriched volcanic rocks ~20 km southeast of the deposit, which incorporated abundant components from the subducting sediment. Based on regional geological, geochemical (major, trace elements and Sr-Nd-Pb isotopes) and geochronological data, we propose that seamount subduction induced the extra sediment input into the mantle wedge, which generated additional magma batches and helped to sustain magmatic-hydrothermal activity in the study area. The large tonnage, particularly of Pb, Zn, Ag, and In, in Toyoha was likely a result of the productive source, which enabled long-lived magmatic-hydrothermal activity, and an effective structure for the transport and trapping of ore-forming materials.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107887"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027313","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":"Magma fractionation and the magmatic-meteoric fluids mixing drive the sequential deposition of cassiterite to lepidolite in the Uljin prospects, South Korea","authors":"Ha Hyun Park ,&nbsp;Jung Hun Seo ,&nbsp;Bum Han Lee ,&nbsp;Chul-Ho Heo ,&nbsp;Marcel Guillong","doi":"10.1016/j.gexplo.2025.107917","DOIUrl":"10.1016/j.gexplo.2025.107917","url":null,"abstract":"<div><div>Several Sn<img>Li prospects in the Uljin area, which is in the eastern part of South Korea, including Dongseok, Yuchang, Buguk, Chomak, Hyundong, and Boam, contain sub-economic cassiterite and Li-bearing silicate minerals such as lepidolite and spodumene, and phosphate mineral such as amblygonite, along with accessory Nb-Ta-bearing minerals. Among these, Dongseok and Yuchang are Sn-dominant, Buguk, Hyundong, and Chomak exhibit mixed Sn<img>Li mineralization, while Boam (Western, Main, Eastern) is Li-rich. The Sn<img>Li mineralization is associated with a series of hydrothermal alterations, particularly greisenization and albitization. Two stages of greisenization have been identified, with albite alteration occurring between them. Cassiterite (± Nb<img>Ta minerals) precipitated during early greisenization (Greisen I), whereas spodumene crystallized as a primary mineral in subsequent pegmatite intrusion, lepidolite and amblygonite formed during late-stage greisenization (Greisen II). SEM-CL analysis distinguishes two types of cassiterite: CL-brighter, oscillatory-zoned type I (commonly found in Dongseok) and CL-darker, massive type II (dominant in Yuchang, Buguk, and Chomak).</div><div>Muscovite Ar<img>Ar dating constrains the timing of greisenization, placing Greisen I (cassiterite formation) at 168–174 Ma and Greisen II (lepidolite formation) at ~166 Ma. These overlapping ages suggest that the Sn<img>Li mineralization was derived from a fractionating magmatic batholith. Fluid inclusions in cassiterite and quartz contain CO₂, CH₄, and N₂, with CH₄/CO₂ ratios indicating a reducing environment during early cassiterite precipitation. A positive correlation between homogenization temperatures and salinities in the fluid inclusions suggests the mixing of magmatic and meteoric fluids during cassiterite and lepidolite precipitation. The transition from Sn to Li mineralization was driven by progressive oxidation and cooling, as reflected in CO₂/CH₄ ratios and cassiterite chemistry. Higher-temperature (&gt;300 °C), lower-salinity fluids (&gt;8 wt% NaCl eq.) formed cassiterite during Greisen I, while later, somewhat cooler (&gt;250 °C), more saline fluids (&gt;10 wt% NaCl eq.) facilitated lepidolite precipitation during Greisen II. This magmatic-hydrothermal evolution, potentially controlled by batholith-scale magma fractionation, resulted in these sequential Sn and Li mineralization in the Uljin area.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107917"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267258","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":"Relationship between provenance-deposition lobes and uranium mineralization: A case study from the northern Songliao basin","authors":"Yang Liu ,&nbsp;Kun Huang ,&nbsp;Hui Rong ,&nbsp;Tao Sun ,&nbsp;Yongpeng Yin","doi":"10.1016/j.gexplo.2025.107907","DOIUrl":"10.1016/j.gexplo.2025.107907","url":null,"abstract":"<div><div>The uranium mineralization in the Sifangtai Formation of the northern Songliao Basin is widely distributed, and the complex origins of its uranium reservoir sand bodies pose significant constraints on uranium deposit prediction and exploration. The uranium mineralization in the Sifangtai Formation of the northern Songliao Basin is extensively distributed, with the complex origins of its uranium reservoir sand bodies posing severe constraints on uranium deposit prediction and exploration. This paper employs comprehensive research methods, including sandstone geochemistry, heavy mineral analysis, and detrital zircon U<img>Pb geochronology, to accurately trace the provenance of uranium reservoir sand bodies in the Sifangtai Formation of the northern Songliao Basin. The research results indicate that the average content of quartz, feldspar, and rock debris in the sandstone of the Sifangtai Formation is 42 %, 37 %, and 21 %, and the CIA is from 61.81 to 72.81 with an average of 68.56. The apatite-tourmaline index of heavy minerals (ATi) in the sandstone of the Sifangtai Formation are mostly greater than 50, the Garnet-Zircon index of heavy minerals (ZGi) is mostly less than 50, and the stable coefficient of heavy minerals (ZTR) ranges from 9.63 % to 35.78 %. The main peak value of detrital zircon is concentrated in the Jurassic-Permian, with ages ranging from 165 to 294 Ma, and the secondary peak is concentrated in the Cretaceous, with ages ranging from 92 to 148 Ma. This study indicates that the uranium reservoirs of the Sifangtai Formation are greywacke and feldspathic sandstone, with the parent rock originating from the upper crust and being the Permian-Jurassic and Early Cretaceous medium acidic magmatic rocks formed in the active continental margin. The western provenance of the Sifangtai Formation is provided by the Daxing'an Moutains, the northern provenance is supplied by the Xiaoxing'an Moutains, and the eastern provenance is offered by the Zhangguangcai Mountains. The source-to-sink system of the Sifangtai Formation has led to the formation of three provenance-deposition lobes in the west, north and east of the northern Songliao Basin, which control the development of the uranium reservoirs. The three provenance-deposition lobes show different uranium mineralization potential, in which the western provenance-deposition lobe has the highest metallogenic potential.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107907"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119050","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":"Lanthanum anomaly as monitor of the burning of fossil fuels pollution in surface soil surrounding the industrial complex in Tula (Mexico City megalopolis)","authors":"Reneé González-Guzmán ,&nbsp;Alejandro Rodríguez-Trejo ,&nbsp;Sara Solís-Valdez ,&nbsp;Luis Alejandro Elizondo-Pacheco ,&nbsp;Zayre I. González-Acevedo ,&nbsp;Héctor Enrique Ibarra-Ortega","doi":"10.1016/j.gexplo.2025.107922","DOIUrl":"10.1016/j.gexplo.2025.107922","url":null,"abstract":"<div><div>Power plants and oil refineries emit a variety of harmful pollutants that pose a significant health risk to the surrounding population. Therefore, it is important to understand the source of pollution to develop indicators for effective environmental management and control the risk of exposure. Lanthanum (La) is a chemical element normally enriched in atmospheric aerosols from oil-burning residues that can be used as pollution tracer but their role as a proxy is rarely documented. This study evaluates the La enrichment in topsoils from the major industrial emission hotspot in the northern part of the Mexico City megalopolis. Twenty-seven topsoil samples and three rocks were collected. Initial characterization of the soils included the evaluation of its physical and chemical properties, such as granulometry, pH_H2O (6.83–8.33), pH_KCl (6.80–7.80), organic carbon (0.58–12.02 %), cation exchange capacity (17.40–80.23 cmolc/kg), and magnetic susceptibility (36.25–153.61 10⁻⁸ m³ kg⁻¹). Soils ranged from sandy loam to silty clay. Elements analyzed by ICP-MS included potentially toxic elements (PTEs: V, Cr, Co, Cu, Ni, Zn, As, Mo, Sn, Sb, Pb), lanthanides (La → Lu), and geogenic elements (Al, Ti, Rb, Zr, Ba, Hf, Th). Both natural and anthropogenic sources influenced the geochemistry of soils in the study area. Based on statistical analyses and ternary diagrams, the enrichment of V<img>Ni is associated with atmospheric residues derived from heavy oil combustion. Magnetic susceptibility data, which are dominated by residual ferromagnetic minerals, correlate with V, Ni, Mo, and La. PAAS-normalized REE patterns mainly reflect local volcanic rock sources, but positive anomalies of La (La/La* &gt; 1) in several samples are related to anthropogenic inputs from the industrial complex. Comparisons between La enrichment and other geochemical and geophysical pollution proxies, combined with spatial interpolation maps, indicate that La/La* is a suitable tracer to monitor soil pollution through the deposition of oil combustion residues on a local scale.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"280 ","pages":"Article 107922"},"PeriodicalIF":3.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362220","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 Bujinhei Pb-Zn deposit in the southern Great Xing'an Range, China: An example of the reduced hydrothermal vein type Pb-Zn mineralization system","authors":"Cheng-yang Wang ,&nbsp;Yun-sheng Ren ,&nbsp;Yi-cun Wang ,&nbsp;Zhen-jun Sun ,&nbsp;Li-juan Fu","doi":"10.1016/j.gexplo.2025.107888","DOIUrl":"10.1016/j.gexplo.2025.107888","url":null,"abstract":"<div><div>The Bujinhei deposit, a representative vein-type Pb-Zn mineralization, is situated on the western slope of the southern Great Xing'an Range (SGXR). The ore bodies of Bujinhei are primarily hosted within Permian sedimentary rocks and structurally controlled by nearly EW-trending faults. Three types of fluid inclusions (FIs), including gas-liquid two-phase inclusions (Type-1), CH₄ (±CO₂)-rich inclusions (Type-2), and pure CH₄-CO₂ inclusions (Type-3) can be recognized in hydrothermal veins. Laser Raman spectral analysis further confirmed that the gas phase of these fluid inclusions contained large amounts of CH₄. Petrographic analysis, microthermometry, and laser Raman spectroscopy of fluid inclusions suggest that the ore-forming fluids comprise a NaCl-H₂O-CH₄ ± CO₂ system, characterized by moderate temperatures and low salinity. Oxygen and hydrogen isotope data for quartz and carbonate from the ore-bearing veins fell between the fields of typical magmatic and meteoric water (δ¹⁸O_fluid = 4.0 ‰–7.2 ‰, δD_fluid = −123.1 ‰ to −112.7 ‰). The extremely low δD_fluid values of Bujinhei fluids could be due to water-rock reactions between ore fluids and carbonaceous strata. The δ¹³C _PDB value of the CH₄ in fluid inclusions ranged from −31.8 ‰ to −27.9 ‰, also suggesting the hydrolysis of organic matter in the sedimentary was involved in the mineralizing fluids. Sulfides from the Bujinhei show restricted δ³⁴S_CDT values of −3.2 to −0.7 ‰, without the diagnostic signature of sedimentary sulfur. These sulfides have ²⁰⁶Pb/²⁰⁴Pb = 18.200–18.285, ²⁰⁷Pb/²⁰⁴Pb = 15.519–15.623, and ²⁰⁸Pb/²⁰⁴Pb = 38.020–38.364, overlapping with most of the hydrothermal vein type deposits, which were sourced primarily from deep-seated magma. Genetically, the Bujinhei Pb-Zn deposit shows characteristics of a typical reduced hydrothermal system, which may be originally magmatic-related and dramatically influenced by carbonaceous-reducing rocks. The investigation results presented in this paper provide compelling evidence that carbonaceous wall rocks exert a substantial influence on the formation of reducing conditions in lead‑zinc ore-forming hydrothermal systems in the southern Great Xing'an Range.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"279 ","pages":"Article 107888"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916564","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":"Metallogenic process of the metasedimentary rock-hosted HREE deposit at Guangshui (Hubei Province, Central China)","authors":"Cheng-Lai Deng ,&nbsp;Shao-Yong Jiang ,&nbsp;Xue-Wen Yuan ,&nbsp;Hui-Min Su ,&nbsp;Wei Wang","doi":"10.1016/j.gexplo.2025.107880","DOIUrl":"10.1016/j.gexplo.2025.107880","url":null,"abstract":"<div><div>Guangshui (Hubei Province, Central China) is an exceptional heavy rare earth element (HREE) deposit that occurred within a series of metasedimentary rock (e.g. leptynite). This study integrates detailed petrography with in situ U-Pb geochronology, Nd isotope systematics, and mineral chemistry of the principal REE phases—gadolinite, fergusonite, monazite and xenotime—to reconstruct the timing, sources and mechanisms of mineralization. Two generations of each mineral are recognized on the basis of crystal habit and paragenesis: Gad-I/II, Fgs-I/II, Mnz-I/II, Xtm-I/II. U-Pb dating of Mnz-I yields an age of 239 ± 13 Ma, while Xtm-I records 210 ± 6 Ma. These ages coincide with prograde and retrograde stages of Triassic high-grade metamorphism in the Dabie orogen, underscoring a direct link between regional metamorphism and HREE mobilization. Petrological observations indicate that the Mnz-I marks the crystallization of the earliest HREE assemblage (Fgs-I + Gad-I), whereas Xtm-I brackets the final stage of HREE mineralization. Geochemical variations between the two mineral generations are evident. Mnz-I and Mnz-II exhibit low Th contents, consistent with a hydrothermal origin. Mnz-II is spatially associated with Xtm-II, and its pronounced HREE enrichment coincides with HREE depletion from Xtm-I to Xtm-II, suggesting that Xtm-II formed via alteration of Xtm-I. Positive Ce anomalies in Fgs-I and Gad-I suggest crystallization under oxidizing conditions. Combined with petrological evidence and geochemical variation, the composition of Gad-II may have affected by coeval hydrothermal zircon crystallization. For Fgs-II, hydrothermal alteration likely facilitated substitution of LREE and Ca for HREE and Y at the A-site. Nd isotope compositions of Mnz-I (ε_Nd(t) = −5.1 to −5.6; T_DM2 = 1.38–1.43 Ga) and Mnz-II (ε_Nd(t) = −4.8 to −5.8; T_DM2 = 1.38–1.45 Ga) indicate a crustal source for the ore-forming materials, most likely derived from Mesoproterozoic rocks. Regionally, the phosphorus-rich Huangmailing Formation and Triassic metamorphism played critical roles in HREE enrichment. Overall, the Guangshui deposit exemplifies HREE mineralization controlled by metamorphism and fluid–rock interaction during continental collision, firmly tying its metallogenesis to the Triassic evolution of the Dabie orogen.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"279 ","pages":"Article 107880"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893910","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}