Journal of Geochemical Exploration最新文献

{"title":"Hydraulic fracturing-induced gold remobilization: Pyrite geochemical and sulfur isotopic insights from the Liuan lode gold deposit, South China","authors":"Xu Wang ,&nbsp;Yu Zhang ,&nbsp;Zebin Tang ,&nbsp;Yongjun Shao ,&nbsp;Bing Xiao ,&nbsp;Shuling Song ,&nbsp;Xingting Sun ,&nbsp;Hongtao Zhao ,&nbsp;Lianjie Zhao","doi":"10.1016/j.gexplo.2026.107994","DOIUrl":"10.1016/j.gexplo.2026.107994","url":null,"abstract":"<div><div>The coupled dissolution-reprecipitation (CDR) process is critical for gold remobilization and re-enrichment within global gold mineralization systems, and its driving mechanism warrants further investigation. The Liuan lode gold deposit in the Dayaoshan district (South China) features multiple generations of pyrite, including Py1 (pre-ore stage), Py2 (including Py2c and Py2r) and Py3 (ore stage), and Py4 (post-ore stage). Py2c is As-Cu-Pb-Ag-Au-rich (initial gold enrichment), suggestive of fluid boiling during its formation, corroborated by low δ³⁴S values (avg. −3.83‰) and hydrothermal breccias. In contrast, Py2r is depleted in these elements, indicative of non-boiling conditions, further supported by heavier δ³⁴S values (avg. −2.53‰). Several pieces of evidence, including sharp reaction fronts and As-Au contents differences between Py2c and Py3, and Py2c remnants and mineral inclusions (chalcopyrite, galena, and native gold) within Py3, indicate the CDR process, during which Au in Py2c was remobilized and reprecipitated as native gold. The CDR process is triggered by oxidation of the mineralizing fluids, consistent with the decreasing δ³⁴S values from Py2r to Py3. Combined with higher Co-Ni concentrations in Py3 (similar to Py2c) relative to Py2r, we infer that fluid oxidation is associated with hydraulic fracturing restart. Multiple sulfur isotopes (δ³⁴S: −4.92 to 0.45‰; Δ³³S: −0.05 ± 0.10‰) and low Co-Ni and high Se contents of pyrite suggest a magmatic fluid origin from a possible concealed intrusion. This study underscores magmatic-hydrothermal contributions in forming lode gold deposits in Dayaoshan, and highlights the importance of pressure-driven hydrothermal processes in initial gold precipitation, remobilization, and reprecipitation within gold deposits.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"284 ","pages":"Article 107994"},"PeriodicalIF":3.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102408","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":"Fluid sources and evolution in the As (±Sb) epithermal Matra deposit (Alpine Corsica, France): Constraints from fluid inclusions, gas compositions, and stable isotopes (C–O)","authors":"Danis Ionut Filimon ,&nbsp;John A. Groff ,&nbsp;Paolo Fulignati ,&nbsp;Maria Di Rosa","doi":"10.1016/j.gexplo.2026.107996","DOIUrl":"10.1016/j.gexplo.2026.107996","url":null,"abstract":"<div><div>The Matra mine (Alpine Corsica, France) was a historic source of high-grade arsenic ores composed of realgar ± stibnite. Prior to this study, no fluid inclusion or stable isotope data were available to characterize hydrothermal fluids and develop a genetic model. As the mineralization is coarse-grained and paragenetic relationships are evident, it is possible to generate data for representative samples that span the mineralizing event. Therefore, samples of quartz, carbonate, and realgar were studied to determine the origin(s) and evolution of mineralizing fluids. The mineralization occurs in a post–Alpine brittle structure formed during Early Miocene extensional tectonism. After the failure of host rocks due to fault movement, boiling of a high-temperature (∼290 °C) and moderately saline (∼9 wt% NaCl_equiv.) hydrothermal solution occurred during pre–ore stage quartz mineralization at depth of 500–800 m. Continued movement along the Matra Fault created permeable zones that allowed mixing between magmatic, evolved meteoric, and meteoric fluids. An increasing influx of meteoric water is indicated by gas-poor fluid inclusions in realgar having T_h ∼ 60 °C and salinities ∼0.5 wt% NaCl_equiv. Fluid mixing is recorded by the distribution of gas data in CO₂/CH₄ vs. N₂/Ar and N₂–Ar–He diagrams combined with C–O isotope data. The magmatic signature could be related to the early opening of the Tyrrhenian Sea, accompanied by crustal thinning and asthenospheric upwelling. In this framework, major tectonic structure of the Matra area could have focused heat flow and deep gases from the mantle to create a dynamic hydrothermal system.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107996"},"PeriodicalIF":3.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078894","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":"Arsenate adsorption onto hydrous ferric oxide: Insights from triple layer surface complexation modeling","authors":"Hafsa Nazir ,&nbsp;Raheena Moozhikkal ,&nbsp;Bhawna Thakur ,&nbsp;Shray Pathak ,&nbsp;Pushpendra P. Singh","doi":"10.1016/j.gexplo.2026.107992","DOIUrl":"10.1016/j.gexplo.2026.107992","url":null,"abstract":"<div><div>This study investigates arsenate [As(V)] adsorption dynamics along soil depth profiles in natural soils from Gurukhwind village, Tarn Taran district, Punjab, using batch adsorption experiments in an arsenic (As) affected region. Kinetic experiments showed rapid As(V) adsorption within the first 4 h, reaching equilibrium at 12 h across all soil layers. As(V) adsorption was substantially higher in surface soil layers than in bottom layers, largely due to variations in surface area, organic matter content, pH, and mineralogical components such as hydrous ferric oxide (HFO). Adsorption decreased with increasing pH, with maximum uptake occurring under acidic conditions due to enhanced electrostatic forces of attraction between protonated surface sites and negatively charged As(V) species. The pseudo-first-order (PFO) model best described the kinetic data, while equilibrium data followed the Langmuir isotherm, indicating monolayer adsorption, with R² values exceeding 0.9 across all soil layers. The 2-pK Triple Layer Model (TLM) successfully simulated the pH-edge and isotherm trends for As(V) adsorption on HFO, suggesting the formation of dominant inner-sphere complexes = Fe(H₂AsO₄), =Fe(HAsO₄)⁻ and = Fe(AsO₄)²⁻ along with minor contribution from outer-sphere complexes FeOH₂⁺_ H₂AsO₄⁻ and FeOH₂⁺ _ HAsO₄²⁻<em>.</em> The good agreement between modeled and experimental data was supported by reasonable RMSE values for isotherms and pH-edge data. The combined findings underscore the importance of iron (Fe) oxide rich surface horizons in controlling As mobility, with direct implications for the development of site specific management and mitigation strategies in As affected regions.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107992"},"PeriodicalIF":3.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078896","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":"A novel integrated model for risk analysis of soil PAHs and PTEs based on Monte Carlo simulation: a case study of Shenyang, China","authors":"Rui Zhong ,&nbsp;Fulin Tian ,&nbsp;Yiran Li ,&nbsp;Zhengyu Liu ,&nbsp;Jingyuan Wei ,&nbsp;Hong Li ,&nbsp;Peng Kang ,&nbsp;Haibo Zhao ,&nbsp;Zhisen Liu","doi":"10.1016/j.gexplo.2026.107993","DOIUrl":"10.1016/j.gexplo.2026.107993","url":null,"abstract":"<div><div>A novel integrated probabilistic model combining Monte Carlo simulation with multi-pollutant risk assessment was developed to evaluate soil contamination risks in urban ecosystems. This MATLAB-based framework establishes an independent computational architecture with native implementation of environmental risk algorithms, eliminating dependencies on external statistical packages. The system demonstrates robust compatibility through standardized interfaces that enable direct coupling with receptor models for integrated source-to-risk analysis. A case study was conducted in Shenyang's urban core (a northeastern Chinese megacity) to evaluate the model. Sixteen priority PAHs and nine potentially toxic elements (PTEs) in the city's surface soils were simultaneously analyzed. The results indicated that the non-carcinogenic risks of PAHs and PTEs were within acceptable levels. However, in terms of carcinogenic risks, 2.50% of children and 17.89% of adults exceeded the recommended guideline value of 10⁻⁴ for PAH exposure. Furthermore, 2.82% of adults surpassed the recommended threshold of 10⁻⁴ for carcinogenic risk linked to Cr exposure, suggesting a potential carcinogenic risk for this demographic. Sensitivity analysis results showed that body weight and exposure duration were the main influencing factors of carcinogenic risk. The model is feasible for application and can be further integrated with other modeling approaches. The current study may represent a significant advancement in enhancing the integration and compatibility of risk analysis modeling frameworks.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107993"},"PeriodicalIF":3.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078869","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":"Structurally-controlled radioactive and rare metal mineralizations associated with potassic alteration in Umm Ara granitoids, southern Eastern Desert, Egypt: Implications from remote sensing, whole-rock chemistry, and geophysical data","authors":"Adel Fathy ,&nbsp;Mokhles K. Azer ,&nbsp;Abdelhalim S. Mahmoud ,&nbsp;Farouk Sayed ,&nbsp;Ahmed A. Masoud ,&nbsp;Faris A. Abanumay","doi":"10.1016/j.gexplo.2026.107990","DOIUrl":"10.1016/j.gexplo.2026.107990","url":null,"abstract":"<div><div>The Umm Ara locality, situated in the extreme southern Eastern Desert of Egypt, hosts one of the richest granitoid-related uranium mineralizations in the region, reaching concentrations of up to 7020 ppm. It forms part of the Allaqi-Heiani Suture Zone, an E-W to NW-trending arc-arc collision zone within the Arabian-Nubian Shield. Three main granite varieties-monzogranite, syenogranite, and alkali feldspar granite-intrude dismembered ophiolitic assemblages, arc-related metavolcanics, and metasediments. Hyperspectral remote sensing, using K-means, Fuzzy C-means, and SID-SAM hybrid algorithms, effectively discriminated the lithological units and mapped alteration minerals such as kaolinite, illite, and muscovite. Radiometric data identified distinct uranium anomalies concentrated within alkali feldspar granites and Dokhan volcanics, spatially controlled by shear zones and fault networks. SEM-EDX analyses revealed diverse accessory minerals, including uranophane, kasolite, allanite, monazite, xenotime, zircon, and the newly recognized polycrase-(Y). Automatic lineament extraction from DEM data indicates dominant structural trends of N–S, NW, NNW, NE, and E–W, with the highest lineament densities occurring within granitoid and Dokhan volcanic rocks. Most of these represent shear-related faults exhibiting either dextral or sinistral motion. These fracture systems enhance permeability and fluid circulation, providing favorable pathways for uranium and rare-metal mineralization. Geochemically, the Umm Ara granitoids display high Fe-numbers, peraluminous compositions, and enrichment in Zr, Y, Nb, Th, and Rb, classifying them as highly fractionated A-type granites of within-plate affinity. Their rare earth element patterns show relatively flat profiles with pronounced negative Eu anomalies, indicative of advanced plagioclase fractionation. The geochemical characteristics suggest derivation from crustal metasedimentary sources in a post-collisional, within-plate tectonic setting. Hydrothermal alteration in the Umm Ara granitoids is dominated by potassic alteration, silicification, and sericitization, with minor albitization. Uranium and rare-metal mineralization are closely associated with these alteration zones, reflecting overprinting by potassic metasomatism. The extreme low Th/U ratio emphasizes the role of post-magmatic processes in U-enrichment. Strong positive correlations between SiO₂ and K₂O with U and other HFSEs emphasize the role of potassic-silicic alteration in rare-metal enrichment. Overall, the integration of remote sensing, structural, mineralogical, and geochemical data demonstrates that structurally controlled potassic alteration and associated hydrothermal processes localized uranium and rare-metal mineralization.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107990"},"PeriodicalIF":3.3,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078895","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":"Boundary-based random forest leveling of multi-map geochemical data: A case study of the Baiyinchagan-Maodeng Area, Inner Mongolia","authors":"Rui Tang ,&nbsp;Cheng Li ,&nbsp;Keyan Xiao","doi":"10.1016/j.gexplo.2026.107991","DOIUrl":"10.1016/j.gexplo.2026.107991","url":null,"abstract":"<div><div>Exploration geochemical data, often compiled from multiple map sheets, are susceptible to systematic errors that create artificial “shift” effects at their boundaries. While linear leveling methods exist, they often fail to capture the complex, non-linear relationships inherent in geochemical data. To address this limitation, this study introduces and validates a novel machine learning approach: the Boundary-based Random Forest (BRF) method. Using data from four map sheets in the Baiyinchagan–Maodeng area, we apply the BRF method, which leverages the non-linear capabilities of Random Forest to model the relationship between adjacent data blocks. We compare its performance against the standard Contrast Return (CR) method. The results demonstrate that the BRF method is significantly more effective at eliminating boundary artifacts. The resulting geochemical maps show a more continuous and geologically coherent distribution, aligning better with known fault zones and mineralization. We conclude that the BRF method represents a robust and superior alternative to linear approaches, offering a more accurate foundation for mineral exploration and anomaly targeting.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107991"},"PeriodicalIF":3.3,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035508","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":"A hybrid spatial framework for risk mapping and driving factor diagnosis of soil combined contamination in Guangzhou","authors":"Lian Chen ,&nbsp;Zhenjiang Wang ,&nbsp;Lingyun Sun ,&nbsp;Zhipeng Wu ,&nbsp;Sen Lin ,&nbsp;Dan Wang ,&nbsp;Jianan Wu ,&nbsp;Zhiyi Li ,&nbsp;Gaocong Li","doi":"10.1016/j.gexplo.2026.107989","DOIUrl":"10.1016/j.gexplo.2026.107989","url":null,"abstract":"<div><div>The spatial characterization of risk patterns and their driving factors in urban soils co-contaminated with potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) remains a critical research challenge. To address this, we developed a novel integrated framework, MGRB (MCDA-GIS-RF-BLMI), that synergistically combines Multi-Criteria Decision Analysis (MCDA), Geographic Information Systems (GIS), Random Forest (RF), and Bivariate Local Moran's I (BLMI). This framework enables comprehensive assessment of combined contamination risks, generation of detailed risk zoning maps, identification of key influencing factors, and analysis of spatial interactions between risk levels and environmental drivers. Guangzhou, a major political, economic, and cultural center in southern China, was applied to the MGRB framework to demonstrate its feasibility and innovation. Results derived from MCDA and GIS revealed a distinct spatial risk gradient, with risk zones distributed as follows: low-risk (55.0%, 4092.4 km²) &gt; moderate-risk (23.1%, 1713.9 km²) &gt; considerable-risk (12.7%, 942.1 km²) &gt; no-risk (7.7%, 572.9 km²) &gt; high-risk (1.5%, 113.0 km²). Notably, approximately 37% of Guangzhou's territory exhibited moderate-to-high risk levels, with significant spatial clustering in western and central districts as well as scattered high-risk patches in northern, eastern, and southern areas. RF analysis identified road density, population density, and GDP as the dominant drivers, displaying most frequently and strongest associations with PTE-PAH risk. BLMI results further indicated that high-high clusters, where both contamination risk levels and driving factors are elevated, were predominantly concentrated in western and southern regions, which should be prioritized for targeted pollution control and mitigation strategies. This study develops an innovative methodology for the comprehensive spatial assessment of combined PTE-PAH risks and their driving factors in Guangzhou. This framework serves both to guide local risk management and to provide a transferable model for other rapidly urbanizing regions with analogous challenges.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107989"},"PeriodicalIF":3.3,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035507","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":"Environmental and circular economy-based characterisation of abandoned mine wastes in the Odiel River basin (southwestern Spain)","authors":"David Caro-Moreno ,&nbsp;Francisco Abel Jiménez-Cantizano ,&nbsp;Lola Yesares ,&nbsp;José María González-Jiménez","doi":"10.1016/j.gexplo.2026.107988","DOIUrl":"10.1016/j.gexplo.2026.107988","url":null,"abstract":"<div><div>The Odiel River basin (southwestern Spain) is severely affected by acid mine drainage resulting from a long history of intensive mining, particularly during the 19th and 20th centuries. This legacy has left numerous abandoned mine wastes scattered across the basin, contributing to widespread contamination of the river system. Many of these materials also contain economically relevant concentrations of critical and high-tech metals. This study evaluates the acid-generation potential of several waste types and provides a preliminary assessment of their suitability for metal recovery. A detailed characterisation was conducted on wastes from 24 abandoned sites, including measurements of surface area, volume, tonnage, acid-generation capacity (via acid–base accounting), and pseudo-total concentrations of 33 elements. Crude sulphide ores, despite their limited volume, exhibit the highest acid generation potential, whereas mixed wastes in dumps pose the greatest environmental risk due to their large tonnage. Roasted pyrite wastes and roasted pyrite ashes are highly enriched in valuable metals, with a preliminary estimated gross recovery value of up to 0.9 billion USD based on the combined contents of the analysed elements. Environmental desulphurisation is proposed as an effective strategy to reduce acidity and enable metal recovery, with the potential to eliminate approximately 80% of the total acidity associated with the studied wastes. Overall, the findings support integrated remediation and resource-recovery approaches consistent with circular-economy principles.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107988"},"PeriodicalIF":3.3,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979851","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":"Genesis of copper mineralization in the Lanping foreland basin, southeastern Tibetan Plateau: Insights from ReOs geochronology and sulfide geochemistry at Baiyangping","authors":"Jiaxuan Zhu ,&nbsp;Qingfei Wang ,&nbsp;Matthew Steele-MacInnis ,&nbsp;Hongyu Duan ,&nbsp;Songyan Liu","doi":"10.1016/j.gexplo.2026.107987","DOIUrl":"10.1016/j.gexplo.2026.107987","url":null,"abstract":"<div><div>A series of sediment-host base metal deposits, related to the collision between the Indian and Asian plates, are distributed in the Lanping basin in the southeastern Tibetan Plateau. The genesis of these deposits remains controversial. Here, we report Re<img>Os isotopic data of chalcopyrite-tennantite and laser ablation mineral mapping from the Baiyangping deposit, a large sediment-hosted Cu<img>Pb<img>Zn deposit. The isochron age, which offers the first insight into the absolute age of the Cu mineralization, at 30.8 ± 1.4 Ma (MSWD = 2.7, n = 5, ±2σ). This demonstrates the application of the low-level Re<img>Os system in chalcopyrite-tennantite dating, with high ¹⁸⁷Re/¹⁸⁸Os (400–10,000 ppb) but low Re abundances (3–20 ppb). La-ICP-MS analysis show that sphalerite intergrown with chalcopyrite from Cu-rich mineralization exhibits a fibrous texture formed in a setting where vein cementation kept pace with dilation and is enriched in Ag, As, Cu and Sb. This is a common feature of basinal rocks influenced by compressional tectonics. In contrast, euhedral sphalerite in Pb<img>Zn orebody is enriched in Fe and Cd and displays concentric and sectoral zoning patterns. It was formed by precipitation into open space, probably assisted by structural dilation along jogs on extensional faults in transpressional or extensional zones. The Baiyangping deposit within thrust belts occurs as a result of synorogenic stress transition from compression to transpression/extension during the Cenozoic after Indo-Asian initial-collision. Regional metallogenesis also shows that Cu mineralization formed along thrust fault during the extrusion and Pb<img>Zn mineralization focus on extensional zones and extensional faults.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107987"},"PeriodicalIF":3.3,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035574","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 evaluation of resource potential in mafic-ultramafic intrusions: A case study on Ni and Co in the Hongshishan complex of Gansu Province, China","authors":"Zhendong Lv ,&nbsp;Ye Liu ,&nbsp;Qingjie Gong ,&nbsp;Haiyun Chen ,&nbsp;Taotao Yan","doi":"10.1016/j.gexplo.2026.107986","DOIUrl":"10.1016/j.gexplo.2026.107986","url":null,"abstract":"<div><div>Mafic-ultramafic intrusions are closely associated with Ni<img>Co mineralization. Geochemical evaluation of resource potential in mafic-ultramafic intrusions plays a crucial role in guiding Ni<img>Co mineral exploration. The Ni<img>Co prospecting potential in the Hongshishan mafic-ultramafic complex in Gansu Province is under consideration. A detailed geochemical exploration of the stream sediment-soil-rock system in the Hongshishan area was conducted in this study to illustrate the method for geochemical evaluation of Ni and Co resource potential in mafic-ultramafic intrusions. The stream sediments originated from the regional geochemical survey with a scale of 1:200,000, the soils were from the detailed geochemical survey with a scale of 1:50,000, and the rocks were collected from the Hongshishan complex and its surrounding strata. For elemental concentrations, a nineteen levels' fixed-value method of concentrations (19LsFC) is used to classify Ni and Co concentrations. In the Hongshishan complex, Ni and Co concentration levels are consistently above the 10th level, even reaching the cut-off grade at the 19th level. Furthermore, their concentrations increase systematically from stream sediments through soils to rocks. For elemental anomalies, a seven levels' classification method of anomalies (7LsAn) is adopted to classify geochemical anomalies of Ni and Co. The anomaly levels of Ni and Co are all higher than the 3rd level and even up to the 7th level (or the cut-off grade level), and increase from stream sediments to rocks in the Hongshishan complex region. Here the 19LsFC on Co is presented on eighteen fixed values, including the analytical detection limit, the median value of surface soils in China, the cut-off grade, etc. The 19LsFC is valid to compare elemental concentrations between different elements and samples in a uniform “ruler”. The 7LsAn is constructed on two “nails” (the background value and the cut-off grade value) for a single sample and is also useful for comparing different elements and samples. The illustration in the Hongshishan area provides a new geochemical approach for Ni<img>Co resource exploration in mafic-ultramafic intrusions.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"283 ","pages":"Article 107986"},"PeriodicalIF":3.3,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979955","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}