Journal of Geochemical Exploration最新文献

{"title":"Host minerals of lithium in Jiujialu Formation Li–rich claystones in South China, and implications for the genesis","authors":"Jihua Yang ,&nbsp;Hanjie Wen ,&nbsp;Chongguang Luo ,&nbsp;Yuxu Zhang ,&nbsp;Wenxiu Yu ,&nbsp;Chuanwei Zhu","doi":"10.1016/j.gexplo.2025.107865","DOIUrl":"10.1016/j.gexplo.2025.107865","url":null,"abstract":"<div><div>Lithium is a critical metal, and recent discoveries have identified significant lithium enrichment in the Late Paleozoic Jiujialu Formation (C₁jj) of southwestern China. However, the specific mineral hosts of lithium remain a topic of debate. This study examines two representative sections of the Jiujialu Formation, utilizing major and trace element analysis, δ⁷Li, SEM-EDS, and XRD techniques. However, previous TOF-SIMS studies have shown that lithium is not enriched in K-rich illite. Furthermore, ion exchange experiments indicate that approximately 6 % of lithium can be exchanged by Na⁺. This finding, combined with δ⁷Li values, XRD patterns, and SEM–EDS data, supports further interpretation. In conjunction with a review of previous research on the formation and transformation of clay minerals, this study suggests that lithium is predominantly hosted in the smectite crystal lattice of illite-smectite mixed layers. It proposes a two-stage diagenetic process for the formation of lithium-rich claystones: the first stage involves the formation of lithium-rich smectite, and the second stage entails the transformation of this smectite into illite and chlorite during diagenesis. In the first stage, weathering of argillaceous dolomite created an alkaline, stagnant, and closed sedimentary environment that facilitated the formation of lithium-rich smectite. In the second stage, lithium-rich smectite, as a precursor, undergoes illitization and chloritization. While illitization leads to the formation of stable illite-smectite mixed layers, chloritization of smectite is less likely to form stable chlorite-smectite mixed layers. Consequently, claystones with higher illite content tend to have higher lithium concentrations. Furthermore, complete illitization and chloritization result in the formation of low-lithium claystones. This study resolves discrepancies in previous research and provides a new perspective on the relationship between the diagenetic processes of lithium-rich claystones and the variations in lithium content.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107865"},"PeriodicalIF":3.3,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722420","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-forming processes of the Chuankou tungsten ore field, South China: New insights into Maowan quartz veins scheelite generation and mineralization genesis","authors":"Or Aimon Brou Koffi Kablan ,&nbsp;Binhai Wang ,&nbsp;Yuzheng Shi ,&nbsp;Syed Yasir Ali Shah ,&nbsp;Baoyi Zhang","doi":"10.1016/j.gexplo.2025.107864","DOIUrl":"10.1016/j.gexplo.2025.107864","url":null,"abstract":"<div><div>The Maowan tungsten quartz vein-type deposit in the Chuankou W area in southern China is predominantly associated with Mesozoic granitic intrusion and Neoproterozoic rocks. Three generations of scheelite (Sch-1, Sch-2a, 2b, and Sch-3) in five types of granite mass were identified based on their occurrences, geochemistry analyses, and mineral paragenesis. The Mo concentration (MoO₃) of scheelite decreases from 34.7 to 14.3 % (Sch-1) to 4.1–2.3 % (Sch-2a), then to 2.3–0.2 % (Sch-2b), and lastly to 0.9–0 % (Sch-3). Values of δ¹⁸O_scheelite and δ¹⁸O_wolframite show relative homogeneous contents (6.62–8.30 ‰ and 7.55–9.56 ‰), while chalcopyrite δ³⁴S ranges between −3.55–1.93 ‰. These changes in composition indicate early magmatism stage from moderate oxidizing to reducing conditions before returning to oxidizing at the late stage. Scheelite substitution mechanisms coupled with the correlation between REE and La reflect strong fluid–rock interactions within Nb-rich environments for Sch-1 and Sch-2, while Na-rich fluids are implied for Sch-3. Granites from Maowan W deposit exhibit two varieties of chondrite-normalized REE patterns, independent of scheelite classification. The type-1 is characterized by an obvious peak of W-enriched, whereas type-2 is MREE-depleted with strong negative Eu anomaly. The relatively wide variations in Nb/Ta vs. Sr and La vs. REE ratios among different generations of scheelite indicate that the hydrothermal fluids responsible for Sch-1 to Sch-3 were derived from remelted mixing fluids, likely associated with local extension under tectonic dominant regime. Study results on scheelite generation and REE precipitation events establish that ore-rich rocks first undergo early-stage metasomatism and filling, then partial fluid melting state releases abundant Ca- and Fe-rich minerals for either scheelite- or wolframite-bearing quartz veins, and refilling occurs through the contribution of recycled meteoric water at the late stage. The distinct variations in REE configuration in scheelite, within the ore field, reflect the multiple levels of mineralization during the metallogenic Episode I event in South China Block.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107864"},"PeriodicalIF":3.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604938","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":"Delineating new targets in a komatiite-hosted magmatic nickel sulfide prospect - Emu Lake, Kalpini, Western Australia","authors":"Louise Schoneveld ,&nbsp;Walid Salama ,&nbsp;Stephen Barnes ,&nbsp;Catherine Spaggiari ,&nbsp;Margaux Le Vaillant","doi":"10.1016/j.gexplo.2025.107863","DOIUrl":"10.1016/j.gexplo.2025.107863","url":null,"abstract":"<div><div>This study tests the use of litho-geochemistry and indicator mineral analysis to delineate new exploration targets within the Emu Lake komatiite-hosted magmatic sulfide prospect within the Archean Eastern Goldfields Superterrane of Western Australia.</div><div>Massive sulfide was recently intercepted at the basal contact of a komatiite unit informally known as the Western ultramafic. The extent of this mineralisation is difficult to track along the ~15 km strike length of the ultramafic sequence due to multiple overlying and underlying barren komatiite flows and significant fault offsets. Whole-rock geochemistry shows that the Western ultramafic unit has distinctly lower Ni/Cr ratios than other ultramafic rocks in the sequence and sits firmly within the 50th percentile of channelised sheet flow komatiitic facies. This Ni/Cr ratio helps distinguish the nickel sulfide-bearing unit from the other komatiitic flows and was used to outline a new target where further drilling was successful in finding sulfide.</div><div>Indicator minerals within the Emu Lake prospect consist of arsenides and chromite. Chromites within the Western ultramafic have lower Ru contents than those within the other ultramafic units, marking interaction between silicate and sulfide melts. Arsenides are also present at Emu Lake and their Pd/Pt values signify arsenic-rich fluids interacted with magmatic sulfide accumulation along shear or fault zones. Surface samples collected above the mineralised area at the Emu Lake prospect contained sulfides (pentlandite and chalcopyrite). Primary sulfides sampled at the surface have the potential to be a powerful ex-situ indicator mineral and could be applied to magmatic sulfide exploration in greenfield terranes.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107863"},"PeriodicalIF":3.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605454","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":"Anaerobic oxidation of antimony under ambient conditions: Complex roles of pH value, soil adsorption and microbial community","authors":"Zikui Zheng ,&nbsp;Yumeng Gao ,&nbsp;Liyuan Ma ,&nbsp;Xingjie Wang ,&nbsp;Hongmei Wang ,&nbsp;Xiaolu Lu ,&nbsp;Deng Liu","doi":"10.1016/j.gexplo.2025.107866","DOIUrl":"10.1016/j.gexplo.2025.107866","url":null,"abstract":"<div><div>The oxidation of Sb(III) to Sb(V) reduces the toxicity of Sb, and nitrate acts as an electron acceptor coupled with Sb(III) oxidation under anaerobic conditions. However, the behavior of antimony anaerobic oxidation under ambient conditions has not been well elucidated. This work investigated the anaerobic oxidation of Sb(III) in soil and soilless microcosms, and the soil adsorption, microbial adsorption and intracellular accumulation of Sb(III) and Sb(V) at different pH values were tracked. In soil microcosms, up to 96.5 % Sb(III) and 19.4 % Sb(V) were adsorbed by soil, and acidic conditions facilitated Sb(V) adsorption. In soilless microcosms, microbial effects on Sb were also pH-dependent. More Sb(III) was adsorbed to the cell surface than Sb(V) under alkaline conditions, and the intracellular accumulation of Sb(III) and Sb(V) achieved a maximum under neutral conditions. The presence of soil significantly changed the composition of the microbial community, enriching anaerobic Sb-oxidizing taxa, including <em>Bacillus</em> and <em>Ensifer</em>, and potentially enhancing overall microbial metabolic activities. These results suggested that the Sb anaerobic oxidation under ambient conditions was a complex process involving many abiotic and biotic factors. Soil adsorption was the main factor that resulted in notable interference when capturing the weak nitrate-dependent Sb oxidation. In this study, the effects of soil pH and microbial influences on Sb presence patterns and potential transport behaviours were investigated to provide important insights into the remediation of Sb-contaminated soils, particularly in anaerobic environments.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"278 ","pages":"Article 107866"},"PeriodicalIF":3.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580386","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":"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}