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Keywords = trace rare-earth element

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26 pages, 7757 KB  
Article
Apatite as an Indicator of Sedimentary Environment and Diagenesis for the Hengyang Neoproterozoic Iron Formation, South China
by Chuangye Zhang, Lei Liu, Kuanxin Huang and Tianyang Hu
Minerals 2026, 16(4), 392; https://doi.org/10.3390/min16040392 - 10 Apr 2026
Abstract
Neoproterozoic iron formations (NIFs), deposited during Cryogenian glaciation events, are critical for understanding early Earth oxidation events and the evolution of glacial–interglacial environments. Apatite, a common accessory mineral in iron formations, holds significant implications for sedimentary environments and diagenetic processes, but these aspects [...] Read more.
Neoproterozoic iron formations (NIFs), deposited during Cryogenian glaciation events, are critical for understanding early Earth oxidation events and the evolution of glacial–interglacial environments. Apatite, a common accessory mineral in iron formations, holds significant implications for sedimentary environments and diagenetic processes, but these aspects remain underexplored. This study focuses on the Hengyang NIF in the Nanhua Basin, South China. Using whole-rock geochemistry and major and trace element analysis of apatite, we investigate the environmental significance of apatite and associated diagenetic processes. Our results show that the Hengyang NIF are formed through the mixing of low-temperature hydrothermal fluids, seawater, and terrigenous detrital materials, with hydrothermal contributions increasing progressively from the bottom to the top of the iron formation layers. Whole-rock geochemical proxies indicate that the depositional water column evolved from relatively oxidizing to weakly oxidizing conditions. The study further demonstrates that the rare earth element patterns in apatite, characterized by middle rare earth element enrichment, are primarily controlled by porewater chemistry during diagenesis. In contrast, Ce anomalies and the V/Cr and V/(V + Ni) ratios in apatite, which are strongly influenced by fluid–rock interactions and magnetite recrystallization, no longer reliably reflect the primary depositional environment. The Th/U ratio in apatite, due to its geochemical stability, aligns with whole-rock trends and serves as a more reliable redox proxy. Based on these findings, we propose a three-stage depositional-diagenetic model: the early and late stages are characterized by high-energy, rapid sedimentation with minimal diagenetic modification, while the middle stage is dominated by low-energy, stagnant conditions with slow sedimentation rates, leading to prolonged diagenesis and significant decoupling of mineral geochemical signatures. This study emphasizes the need to distinguish between sedimentary and diagenetic signals when using mineral geochemical proxies to reconstruct paleoenvironments and provides new insights into the genesis of Neoproterozoic iron formations. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
26 pages, 12108 KB  
Article
Mineralogy, Geochemistry, and Geochronology of Hydrothermal and Magmatic Apatites in the Xiangshan Ore Field, South China: Implications for U-Pb-Zn Polymetallic Mineralization
by Qingkun Yang, Yubin Liu, Fusheng Guo, Hao Jiang, Yongjie Yan and Yun Wang
Minerals 2026, 16(4), 389; https://doi.org/10.3390/min16040389 - 7 Apr 2026
Abstract
The timing of uranium mineralization in the Xiangshan ore field has long been controversial. Although various geochronometers have been applied by previous researchers, including pyrite Rb-Sr, mica Ar-Ar, and fluorite Sm-Nd, the results remain inconsistent and inconclusive. In recent years, the discovery of [...] Read more.
The timing of uranium mineralization in the Xiangshan ore field has long been controversial. Although various geochronometers have been applied by previous researchers, including pyrite Rb-Sr, mica Ar-Ar, and fluorite Sm-Nd, the results remain inconsistent and inconclusive. In recent years, the discovery of abundant Pb-Zn veins in the deeper parts of the Xiangshan ore field has further complicated the interpretation of its metallogenic history. In this study, abundant vein-type hydrothermal apatites closely associated with U-Pb-Zn polymetallic mineralization were identified in both uranium and Pb-Zn ore veins. Combined major-element Electron Probe Microprobe Analysis (EPMA), Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) U-Pb dating, and trace-element analysis were conducted on these apatite grains. The results suggest a mineralization age of 130.9 ± 1.1 Ma for the Shannan uranium deposit, which is consistent with the previously reported apatite U-Pb age of 131.3 ± 7.2 Ma from the Zoujiashan uranium deposit and coincides with the main pulse of volcanic-intrusive activity in the Xiangshan ore field (133–137 Ma). The deep Niutoushan Pb-Zn deposit suggests a younger mineralization age of 124.5 ± 1.3 Ma, which is consistent with a thermal event age of 125.6 Ma determined by zircon fission-track dating and the zircon LA-ICP-MS U-Pb age of late-stage granite porphyry (125.4 ± 1.0 Ma). These ages may constrain the timing of U-Pb-Zn polymetallic mineralization in the Xiangshan ore field. Both magmatic and hydrothermal apatites are classified as fluorapatite and exhibit similar chondrite-normalized rare earth element (REE) patterns. Compared with magmatic apatites, hydrothermal apatites are characterized by elevated Th, U, Ca, and Sr contents, depletion in light rare earth elements (LREEs), Mn, and Na, and distinctly lower Th/U ratios. On major-element variation diagrams, magmatic and hydrothermal apatites define coherent trends but display clear compositional differences related to their formation stages. Apatites from uranium ore veins show strongly negative Eu anomalies and weakly positive Ce anomalies, similar to magmatic apatites. In contrast, apatites from Pb-Zn ore veins display positive Eu anomalies and weakly negative Ce anomalies, with lower Mn and Ga contents and higher SO3 contents relative to both magmatic apatites and hydrothermal apatites from uranium ore veins. These features indicate that the ore-forming fluids during Pb-Zn mineralization were characterized by significantly higher oxygen fugacity than those during uranium mineralization and magmatism. Combined with published Sr isotopic data for the Xiangshan ore field, we propose that both uranium and Pb-Zn mineralization were genetically linked to the prolonged magmatic evolution of the deep volcanic-intrusive complex. The subsequent incursion of meteoric water modified the physicochemical conditions of the ore-forming system, particularly during the formation of the Pb-Zn mineralization. Full article
(This article belongs to the Special Issue Geochemical Exploration for Critical Mineral Resources, 2nd Edition)
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31 pages, 10284 KB  
Article
Combined Effects of Cultivar, Vintage, and Vinification Practices on the Physicochemical, Phenolic, and Elemental Composition of Red and White Wines from Murfatlar (Romania)
by Traian Ciprian Stroe, Ana-Maria Stoenescu, Anamaria Tănase, Ionica Dina, Victoria Artem, Traian Ștefan Cosma, Mihaela Cioată, Aurora Ranca, Anca Becze, Claudiu Tănăselia, Daniela Doloris Cichi, Constantin Băducă Cîmpeanu, Gabriela Ianculescu and Mihai Botu
Horticulturae 2026, 12(4), 434; https://doi.org/10.3390/horticulturae12040434 - 2 Apr 2026
Viewed by 924
Abstract
Grapevine cultivar, climatic variability, and vinification practices are key determinants of wine composition. This study evaluated the physicochemical, phenolic, and elemental profiles of six wines produced from distinct cultivars cultivated in the Murfatlar Research Station (Romania) over three consecutive growing seasons (2022–2025). Red [...] Read more.
Grapevine cultivar, climatic variability, and vinification practices are key determinants of wine composition. This study evaluated the physicochemical, phenolic, and elemental profiles of six wines produced from distinct cultivars cultivated in the Murfatlar Research Station (Romania) over three consecutive growing seasons (2022–2025). Red wines were obtained using differentiated maceration regimes, while white wines were produced with controlled lees contact. Total phenolic content was determined by the Folin–Ciocâlteu method, resveratrol by UHPLC-DAD, and mineral composition by ICP-MS. Linear mixed-effects models were applied to assess the effects of cultivar, vinification method, and vintage year. As expected, red wines exhibited significantly higher total phenolic and resveratrol concentrations than white wines, and maceration duration enhanced phenolic extraction. Cultivar exerted the strongest influence on physicochemical parameters and elemental composition, whereas climatic differences among vintages induced moderate but significant variations. Rare-earth elements and selected macro- and microelements exhibited consistent varietal patterns, supporting their potential as compositional markers. Toxic element concentrations remained within established regulatory limits. These findings highlight the combined influence of genetic, environmental, and technological factors on wine composition and support the integration of phenolic and mineral profiling for varietal differentiation and quality assessment. Full article
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21 pages, 6646 KB  
Article
Whole-Rock Element Analyses Constraining the Magmatic Evolution and Metallogenesis of the Jiaojia Fault Zone, Jiaodong Gold Province
by Jiabao Jia, Yueliang Hu, Lin Gao, Yulu Lv, Junjie Wang, Xiaomei Yang, Yan Liu, Xiaoliang Shi, Jing Lv, Yanbo Xu, Mengmeng Zhang and Wu Li
Minerals 2026, 16(4), 350; https://doi.org/10.3390/min16040350 - 26 Mar 2026
Viewed by 303
Abstract
The Jiaodong Peninsula constitutes a world-class gold province in eastern China, containing more than 5000 t of identified gold resources. The Jiaojia gold deposit is one of the largest deposits within this gold province, and mineralization is primarily distributed along the northern segment [...] Read more.
The Jiaodong Peninsula constitutes a world-class gold province in eastern China, containing more than 5000 t of identified gold resources. The Jiaojia gold deposit is one of the largest deposits within this gold province, and mineralization is primarily distributed along the northern segment of the Jiaojia Fault. The structural characteristics and mineralization processes of the northern segment have been extensively documented. In contrast, the ore-forming mechanisms of the southern Jiaojia Fault remain poorly constrained, hindering further exploration targeting. We chose several gold deposits and one drill core along the Jiaojia Fault, then present whole-rock major and trace elements data to evaluate magmatic affinities and their ore-forming potential. The results show that the lithological differences in plutonic and stratigraphic units suggest that variations in petrogenesis may have exerted a fundamental control on mineralization styles. Almost all samples are characterized by enrichment in light rare earth elements, relative enrichment in Europium, and pronounced depletion in heavy rare earth elements. Alteration characteristics indicate the northern segment is dominated by advanced argillic alteration, whereas phyllic alteration is more prevalent in the southern segment. The rare earth elements discrimination plot clearly suggests differentiation from the northern and southern fault segments. Consequently, we propose that the northern segment records synorogenic arc magmatism, while the southern segment experienced both synorogenic and a subsequent intraplate extensional transitional stage. Full article
(This article belongs to the Special Issue Gold–Polymetallic Deposits in Convergent Margins)
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14 pages, 2506 KB  
Article
Trace Elements and REEs of the Late Cretaceous Halite from Thakhek Basin, Laos and Its Paleoenvironmental Implication
by Jinyang Sha, Huijing Yin, Xize Zeng and Hua Zhang
Minerals 2026, 16(4), 346; https://doi.org/10.3390/min16040346 - 26 Mar 2026
Viewed by 368
Abstract
Rare earth elements (REEs) play a critical role in provenance tracing and the environmental reconstruction of the Earth. However, systematic investigations into the geochemical behavior and fractionation mechanisms of REEs during halite crystallization in brine–salt systems remain limited. This study reports new trace [...] Read more.
Rare earth elements (REEs) play a critical role in provenance tracing and the environmental reconstruction of the Earth. However, systematic investigations into the geochemical behavior and fractionation mechanisms of REEs during halite crystallization in brine–salt systems remain limited. This study reports new trace element and REE data for Late Cretaceous halites from the Thakhek Basin, Laos. Ratios of Sr/Ba, Sr/Cu, and V/Cr indicate a marine origin for the halites, which formed under hot climatic and oscillating oxidizing–anoxic redox conditions. Both primary and secondary halites display uniform Post-Archean Australian Shale (PAAS)-normalized REE distribution patterns, characterized by relative enrichment in medium rare earth elements (MREE) and depletion in light (LREE) and heavy rare earth elements (HREE). Similar REE patterns are also observed in halites from other modern and ancient, continental and marine salt basins worldwide. These observations suggest that the influences of parent brine composition and external provenance supplies on REE fractionation are negligible, given the consistent source, salinity, and redox conditions recorded in these halites. Accordingly, REE fractionation in halite was largely controlled by crystallographic effects, with aqueous MREE preferentially incorporated into halite crystals during deposition. In addition, the relatively lower Zr/Hf ratios in secondary halites compared to primary halites further validate the utility of the Zr/Hf ratio for distinguishing authigenic halite from salt modified by diagenesis, weathering, dissolution, or recrystallization. While our results establish a fundamental REE distribution pattern for halite, further research is needed to better constrain the underlying fractionation mechanisms of REEs in evaporite minerals within brine–salt systems. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
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21 pages, 7513 KB  
Article
The Geochronology and Geochemistry of Zircon and Apatite from the Shenshan Epimetamorphic Rocks in Ningdu, China: Implications for Ion-Adsorption-Type REE Metallogenesis
by Shuilong Wang, Huihu Fan, Luping Zeng, Dehai Wu, Wei Wan and Junpeng Wang
Minerals 2026, 16(3), 324; https://doi.org/10.3390/min16030324 - 19 Mar 2026
Viewed by 304
Abstract
In recent decades, ion-adsorption-type rare earth element (iREE) deposits have been widely documented in the weathering crusts of granitic and volcanic rocks and their geological characteristics and genetic mechanisms extensively studied. Ion-adsorption-type REE mineralization was documented for the first time in the weathered [...] Read more.
In recent decades, ion-adsorption-type rare earth element (iREE) deposits have been widely documented in the weathering crusts of granitic and volcanic rocks and their geological characteristics and genetic mechanisms extensively studied. Ion-adsorption-type REE mineralization was documented for the first time in the weathered crust overlying the epimetamorphic rocks in Ningdu County, China. In contrast to well-documented granite-derived weathering profiles, investigations of epimetamorphic rocks as protoliths for such REE deposits remain limited, particularly regarding the mineralogy of REE-bearing phases and the geochronology and geochemistry of their parent rocks. To address this gap, the present study combines comprehensive petrographic and mineralogical analyses of REE-mineralized Shenshan Formation phyllites with the U–Pb dating of zircon and apatite and trace element geochemical investigations. U–Pb zircon and apatite geochronology yields a protolith age of ca. 785 Ma for Shenshan Formation metamorphic rocks, consistent with mid-Neoproterozoic magmatism. REE-bearing minerals in the Shenshan Formation phyllites comprise allanite-(Ce), apatite, cerianite-(Ce), monazite-(Ce), rhabdophane-(La), rutile, Y-bearing thorianite and xenotime-(Y). Among these, apatite is the most abundant and likely the principal source of ionic REEs in the deposit. Ti-in-zircon thermometry indicates crystallization temperatures of 641–749 °C (mean ~704 °C), reflecting a prolonged magmatic–hydrothermal evolution. This extended history chiefly controlled the differentiation and redistribution of rare earth elements (REEs), thus governing their availability for subsequent supergene enrichment. Zircon-based oxygen fugacity (fO2) estimates a range from −31.4 to −9.9 (mean −17.9), consistent with reduced magmatic conditions. Trace element correlation diagrams for zircon and apatite indicate that the intrusion underwent an extensive fractional crystallization of accessory phases (zircon, monazite, apatite, titanite, rutile) and plagioclase. The distribution patterns of trace elements further suggest that the Shenshan Formation protolith formed in a continental margin arc or arc-related orogenic belt setting, with geochemical signatures characteristic of an S-type granite. The Shenshan Formation phyllites in southern Jiangxi exhibit high REE abundances and host a labile assemblage of weatherable REE-bearing minerals, providing an optimal material framework for ion-adsorption-type REE deposits and indicating substantial mineralization potential. Full article
(This article belongs to the Special Issue Advances in Granite Geochronology and Geochemistry)
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26 pages, 6365 KB  
Article
Geochemical Behaviors and Constraints on REE Enrichment in Weathered Crust of Shallow Metamorphic Rocks: Insights from the Getengzui Ion-Adsorption REE Deposit, South China
by Huihu Fan, Zhenya Chen, Luping Zeng, Dehai Wu, Fuyong Qi, Zhenghui Chen, Tao Wang, Wei Wan and Shuilong Wang
Minerals 2026, 16(3), 321; https://doi.org/10.3390/min16030321 - 19 Mar 2026
Viewed by 263
Abstract
Ion-adsorption rare earth element (REE) deposits represent strategic critical resources in China, which were traditionally considered to be predominantly hosted in granite weathering crusts. However, the recent discovery of new deposit types within the weathering crusts of shallow metamorphic rocks in South China [...] Read more.
Ion-adsorption rare earth element (REE) deposits represent strategic critical resources in China, which were traditionally considered to be predominantly hosted in granite weathering crusts. However, the recent discovery of new deposit types within the weathering crusts of shallow metamorphic rocks in South China has opened up novel exploration frontiers, while research on their metallogenic mechanisms remains insufficient. To elucidate the REE enrichment mechanisms in shallow metamorphic rock weathering crusts, this study focuses on the Getengzui ion-adsorption REE deposit in southern Jiangxi Province. Twenty-four samples were collected from the weathering crust profiles of the Qingbaikouan Shenshan and Kuli Formations. Multiple analytical approaches were employed, including major and trace element analysis, Chemical Index of Alteration (CIA), Base Leaching Index (BA), and quantitative evaluation of element mass transfer coefficients (τ). Trace element spider diagrams, REE distribution patterns, and A-CN-K diagram analysis were also utilized. The results reveal that the weathering crusts have progressed to the middle–late stage of chemical weathering. The average CIA value is 83 for the middle-upper part of the completely weathered horizon in the Kuli Formation. In contrast, for the completely weathered horizon in the Shenshan Formation, the value is 86. Intense chemical weathering has resulted in the near-complete decomposition of primary silicate minerals and extensive leaching of base cations. This progress has created an acidic pore water environment, which is critical for REE mobilization. REEs exhibit characteristics of in situ secondary enrichment, with significant enrichment of ΣREE in the middle-upper part of the completely weathered horizon. The peak τ(ΣREE) values reach 0.78 and 2.43 for the Kuli and Shenshan Formations, respectively. Apatite dissolution is identified as the primary source of REE ions. Differences exist in the geochemical mobility sequences of elements between the two formations. REE enrichment is controlled by multi-stage geochemical barriers, including an oxidation barrier and a clay adsorption barrier. The oxidation barrier preferentially fixes Ce4+, whereas the clay adsorption barrier serves as the dominant mechanism for large-scale REE enrichment. Parent rock lithology is the primary factor governing the efficiency, scale, and fractionation characteristics of REE enrichment. The Kuli Formation is favorable for forming the thick, large-scale orebodies enriched in light rare earth elements (LREEs). In the contrast, the Shenshan Formation tends to host higher-grade orebodies, characterized by a relatively balanced ratio of LREEs and heavy rare earth elements (HREEs). This study clarifies the main controlling factors for ion-adsorption REE mineralization in two shallow metamorphic rocks. It thereby provides a theoretical basis for future exploration. This framework is applicable to analogous REE resources within shallow metamorphic rock distributions across South China and nationwide. Full article
(This article belongs to the Special Issue Geochemical Exploration for Critical Mineral Resources, 2nd Edition)
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29 pages, 6412 KB  
Article
Petrology and Phase Equilibria of Eclogites at Dongyuemiao, Western Dabie, and Implications for Fluid Activity in Continental Subduction Channel
by Haojie Li, Bin Xia and Ying Cui
Minerals 2026, 16(3), 298; https://doi.org/10.3390/min16030298 - 12 Mar 2026
Viewed by 332
Abstract
Eclogites exhumed from subduction channels are pivotal for deciphering the thermal structure of continental subduction zones. However, heterogeneities in bulk-rock composition and evolutionary history within the subduction channel can lead to variations in petrographic textures and elemental characteristics among eclogites. Therefore, investigating the [...] Read more.
Eclogites exhumed from subduction channels are pivotal for deciphering the thermal structure of continental subduction zones. However, heterogeneities in bulk-rock composition and evolutionary history within the subduction channel can lead to variations in petrographic textures and elemental characteristics among eclogites. Therefore, investigating the pressure–temperature (P-T) evolution of eclogites from different outcrops is crucial for refining dynamic models of convergent plate boundaries. The Western Dabie Mountain represents an ideal locality for studying the petro-thermodynamics of continental subduction channels. This study focuses on samples collected from the Dongyuemiao area, situated at the boundary between the high-pressure and ultrahigh-pressure metamorphic belts in the Western Dabie. We integrate petrographic observations, mineral chemistry, phase equilibrium modeling, Zr-in-rutile thermometry and hornblende-plagioclase thermobarometry to constrain the P-T evolution of the eclogite. The samples exhibit a consistent mineral assemblage: garnet + omphacite + amphibole + quartz + phengite, with accessory minerals including rutile and titanite. Garnet grains display characteristic “cloudy-core” and “atoll” textures. Major and trace element analyses of large garnet porphyroblasts reveal pronounced growth zoning in divalent cations, with cores showing enrichment in light rare earth elements (LREEs). Based on phase equilibrium modeling and calculated isopleths for garnet (Ca, Mg) and phengite (Si content), we interpret that the garnet core mineral assemblage (glaucophane + rutile + sphene) records a blueschist-facies metamorphic stage, situated near the rutile-titanite transition. A prograde P-T path is reconstructed, comprising an initial stage of isobaric heating (from ~480 °C at 20 kbar to ~550 °C at 21 kbar), followed by an isothermal compression to the Pmax stage (from ~550 °C at 21 kbar to ~575 °C at 26 kbar). Subsequent retrograde evolution is characterized by decompression and cooling, with symplectite formation recording conditions of ~570 °C and 13 kbar. This study demonstrates that the reconstructed P-T path for the Dongyuemiao eclogites shows stepped geothermal gradient for the prograde stage, and that fluid activity during exhumation resulted from a combination of internal and external factors. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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20 pages, 27052 KB  
Article
REE Enrichment Process in the Maoniuping Carbonatite-Related REE Deposits, Mianning, Sichuan: Genetic and Mineralogical Evidence
by Yanan Jin, Wei Wang, Bin He, Zhi Zhao and Ruiwei Zhao
Minerals 2026, 16(3), 257; https://doi.org/10.3390/min16030257 - 28 Feb 2026
Viewed by 291
Abstract
The Maoniuping deposit, recognized as the world’s third-largest light rare earth (LREE) deposit, is characterized by exceptional ore-forming conditions and considerable exploration potential. Based on systematic mineralogical investigations of chevkinite, allanite, and bastnäsite, this paper synthesizes the trace elements and rare-earth element (REE) [...] Read more.
The Maoniuping deposit, recognized as the world’s third-largest light rare earth (LREE) deposit, is characterized by exceptional ore-forming conditions and considerable exploration potential. Based on systematic mineralogical investigations of chevkinite, allanite, and bastnäsite, this paper synthesizes the trace elements and rare-earth element (REE) geochemical characteristics of these minerals to elucidate their enrichment mechanisms and metallogenic processes. The results reveal a crystallization sequence of chevkinite → allanite → bastnäsite, accompanied by a progressive decrease in the content of Nb, Ta, Zr, Hf, Sr, and Ba. This trend indicates continuous magmatic–hydrothermal evolution of the ore-forming fluids. REE enrichment exhibits distinct stages: early-stage enrichment of HREE, mid-stage enrichment of Ce, Pr, and Nd, and late-stage dominance of La. For chevkinite (δCe = 0.98–1.11, avg. 1.05; δEu = 0.75–0.87, avg. 0.82) and bastnäsite (δCe = 0.81–1.15, avg. 0.88; δEu = 0.58–0.79, avg. 0.66), the evolution process of the continuous increase in oxygen fugacity within the metallogenic system is recorded. The low-temperature, high-oxygen fugacity environment facilitates the incorporation of LREEs into bastnäsite lattices, enabling the formation of large-scale REE ore bodies at structurally favorable positions. These findings provide direct mineralogical evidence for understanding REE enrichment mechanisms in alkaline magmatic–hydrothermal systems and offer crucial insights for metallogenic process inversion and exploration assessment of analogous REE deposits. Full article
(This article belongs to the Section Mineral Deposits)
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39 pages, 1877 KB  
Article
Rare Earth Elements and Technology-Related Trace Metals in Paediatric Scalp Hair: A 2001 Urban Baseline from Spain
by Antonio Peña-Fernández, Manuel Higueras, Roberto Valiente Borox and M. Carmen Lobo-Bedmar
J. Xenobiot. 2026, 16(1), 38; https://doi.org/10.3390/jox16010038 - 23 Feb 2026
Cited by 1 | Viewed by 595
Abstract
Rare earth elements (REEs) and technology-related trace elements are increasingly used in modern products and processes, but biomonitoring data in healthy children and adolescents remain scarce; scalp hair provides a practical, integrative matrix for assessing multi-element patterns over time. Scalp hair collected in [...] Read more.
Rare earth elements (REEs) and technology-related trace elements are increasingly used in modern products and processes, but biomonitoring data in healthy children and adolescents remain scarce; scalp hair provides a practical, integrative matrix for assessing multi-element patterns over time. Scalp hair collected in April–May 2001 from children (6–9 years; n = 120) and adolescents (13–16 years; n = 97) living in Alcalá de Henares (Spain) was retrieved from archival storage and analysed in 2025 using a single QA/QC-controlled ICP–MS workflow. Seven REEs (Ce, La, Pr, Nd, Gd, Er, and Y) and nine technology-related trace elements (Bi, Sb, Th, U, Pd, Pt, Rh, Ir, and Rb) were quantified after rigorous decontamination; left-censored data were treated using Kaplan–Meier, regression on order statistics, and maximum-likelihood approaches, and population reference values were derived as percentile-based upper limits (P95, 95% CI). In children, REEs were frequently detected and showed strong within-suite covariation, with medians in the low ng g−1 range (e.g., Ce ≈ 0.011 µg g−1; La ≈ 0.007 µg g−1), whereas in adolescents, most REEs were near reporting limits. Sb and U were ubiquitous in both age groups, while platinum-group elements were largely undetected. Shale-normalised REE patterns were subparallel across normalisers, La/Ce anomalies were centred below unity, and weak soil–hair correlations suggested multiple microenvironmental exposure pathways. These data provide a robust pre-diffusion baseline for REE metals in European youth, offering a benchmark for future urban exposome assessments. Full article
(This article belongs to the Section Emerging Chemicals)
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18 pages, 3452 KB  
Article
Isotopic and Geochemical Features of High-Hafnium Zircons of the Vasin-Mylk LCT Pegmatite, Kola Peninsula: Compositional Zoning and Crystallization Conditions
by Ekaterina V. Kovalenko (Levashova), Nikolai M. Kudryashov, Sergey G. Skublov, Vladislav G. Kurichev and Xian-Hua Li
Geosciences 2026, 16(2), 77; https://doi.org/10.3390/geosciences16020077 - 10 Feb 2026
Viewed by 646
Abstract
A comprehensive investigation was conducted on high-hafnium zircons from the LCT (Li-Cs-Ta) pegmatites of the Vasin-Mylk rare-metal deposit within the Fennoscandian Shield. In situ analysis of trace element composition and oxygen isotope ratios were performed using secondary ion mass spectrometry (SIMS), complemented by [...] Read more.
A comprehensive investigation was conducted on high-hafnium zircons from the LCT (Li-Cs-Ta) pegmatites of the Vasin-Mylk rare-metal deposit within the Fennoscandian Shield. In situ analysis of trace element composition and oxygen isotope ratios were performed using secondary ion mass spectrometry (SIMS), complemented by internal structural examination via scanning electron microscopy (SEM). The research focuses on deciphering compositional zoning within zircon crystals and characterizing their geochemical signatures to constrain crystallization conditions. The study revealed anomalously high concentrations of Hf (up to 381,000 ppm) and Li (up to 152 ppm), paired with extremely low abundances of U (~10 ppm) and total rare earth elements (~35 ppm). Marked geochemical contrasts were identified between the central and rim domains of the zircons. Central zones display well-fractionated rare earth element (REE) patterns featuring positive Ce and negative Eu anomalies, while the high-Hf rims exhibit weakly differentiated spectra with variable Ce anomalies. The identified W-type tetrad effect suggests crystallization from a melt strongly influenced by coexisting fluids. The obtained δ18O values are consistent with a mantle source and suggest crystallization within a system closed to external fluids. The zircons from the Vasin-Mylk deposit crystallized during the transitional period between the late magmatic and early hydrothermal stages of a highly differentiated pegmatite system. These results contribute to a better understanding of ore genesis in LCT pegmatite systems. Full article
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34 pages, 14603 KB  
Article
Genesis of Gold Mineralization at Rodruin Prospect, Eastern Desert, Egypt: Evaluating Metamorphic vs. Magmatic Fluid Contributions
by Abdelhalim S. Mahmoud, Hanaa A. El-Dokouny, Mai A. El-Lithy, Ali Shebl, Maher Dawoud, Farouk Sayed and Mohamed M. Ghoneim
Resources 2026, 15(2), 29; https://doi.org/10.3390/resources15020029 - 9 Feb 2026
Cited by 1 | Viewed by 939
Abstract
This study investigates the genesis of gold mineralization at the Rodruin prospect in the central Eastern Desert (CED) of Egypt, with the aim of constraining the relative contributions of metamorphic and magmatic fluids to ore formation. Gold mineralization at Rodruin is hosted by [...] Read more.
This study investigates the genesis of gold mineralization at the Rodruin prospect in the central Eastern Desert (CED) of Egypt, with the aim of constraining the relative contributions of metamorphic and magmatic fluids to ore formation. Gold mineralization at Rodruin is hosted by quartz–carbonate veins emplaced within a shear zone that transects low-grade metasedimentary sequences intruded by Ediacaran post-tectonic granitoids. It exhibits characteristics transitional between orogenic turbidite-hosted and polymetallic vein-type mineralization. Although metamorphic devolatilization is interpreted to have generated the dominant ore-forming fluids, adjacent granitoid intrusions acted primarily as a thermal engine, with only a limited direct input of magmatic-hydrothermal fluids. This interpretation is supported by the occurrence of magmatic-affiliated mineral inclusions (monazite, cassiterite, and zircon) coupled with generally low concentrations of trace elements typically enriched in granitic magmatic-hydrothermal fluids (Sb, Bi, Mo, W, Sn, Nb, and Ta), collectively indicating a subordinate magmatic contribution. Rare earth element (REE) patterns of the ore samples closely resemble those of the nearby granitoids, displaying LREE enrichment; however, a distinct positive Eu anomaly is restricted to the ore assemblages and is attributed to hydrothermal feldspar alteration supporting magmatic involvement in ore formation. Carbon and oxygen isotope compositions (δ13C = −6.6 to −2.36‰; δ18O = +15.7 to +19.7‰), together with REE signatures comparable to primitive mantle values and textural evidence for synchronous sulfide–carbonate precipitation, manifested by rhythmic banding of carbonates and sulfides unequivocally indicate a hydrothermal–metasomatic origin. Collectively, these lines of evidence support a hybrid metamorphic–magmatic model in which gold and associated base metals were predominantly transported by metamorphic fluids, whose mobilization and focusing were enhanced by the thermal influence of Younger granitic intrusions, whereas magmatic-hydrothermal fluids contributed only a minor proportion to the overall metal budget. Full article
(This article belongs to the Special Issue Mineral Resource Management 2025: Assessment, Mining and Processing)
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23 pages, 3087 KB  
Article
Provenance Discrimination of Ming Dynasty (1368–1644 CE) Imitated Longquan Celadon from Jianyang Bowl Kiln and Jingdezhen Kiln
by Xuan Lv, Zhen Wang, Maolin Zhang, Min Wang and Guoping Pan
Ceramics 2026, 9(2), 22; https://doi.org/10.3390/ceramics9020022 - 9 Feb 2026
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Abstract
Longquan celadon represents the pinnacle of Chinese celadon, and there are many kilns in southern China that imitate Longquan celadon. During the Ming Dynasty, Jianyang Bowl Kiln was the representative kiln in Fujian Province for imitating Longquan celadon, while Jingdezhen Kiln was the [...] Read more.
Longquan celadon represents the pinnacle of Chinese celadon, and there are many kilns in southern China that imitate Longquan celadon. During the Ming Dynasty, Jianyang Bowl Kiln was the representative kiln in Fujian Province for imitating Longquan celadon, while Jingdezhen Kiln was the representative kiln in Jiangxi Province for imitating Longquan celadon. The quality of both is close to that of Longquan celadon, making it difficult to distinguish by ordinary visual observation. This study focuses on Jianyang Bowl Kiln and Jingdezhen Kiln imitating Longquan celadon, comprehensively employing methods such as EDXRF, LA-ICP-MS, and chromaticity analysis to systematically investigate the similarities and differences in the composition of their body and glaze. The results indicate that distinct differences exist in the composition of trace and rare earth elements between the imitations of Longquan celadon produced by Jianyang Bowl Kiln and Jingdezhen Kiln, and authentic celadons from Longquan Kiln, which can serve as important criteria for distinguishing kilns. This provides systematic scientific data support for identifying the technological origins and production locations of Ming Dynasty imitations of Longquan celadon. Full article
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25 pages, 22059 KB  
Article
Geochronology, Geochemistry, and Geological Implications of the Baiyingaolao Formation Volcanic Rocks in the Tulihe Area, Northern Great Xing’an Range, NE China
by Taotao Wu, Cong Chen, Yu Fan, Xiangxi Meng, Liangxi Chen, Qingshuang Wang and Yongheng Zhou
Minerals 2026, 16(2), 166; https://doi.org/10.3390/min16020166 - 31 Jan 2026
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Abstract
The northern segment of the Great Xing’an Range, northeastern China, hosts a previously unrecognized near-E–W-trending rhyolite belt in the Tulihe area. We conducted systematic geochronological and geochemical investigations to constrain its formation age, petrogenesis, and regional tectonic significance. Field investigation, petrographic observation, and [...] Read more.
The northern segment of the Great Xing’an Range, northeastern China, hosts a previously unrecognized near-E–W-trending rhyolite belt in the Tulihe area. We conducted systematic geochronological and geochemical investigations to constrain its formation age, petrogenesis, and regional tectonic significance. Field investigation, petrographic observation, and zircon laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) U–Pb dating indicate that the rhyolite belt was formed during the Early Cretaceous, with emplacement ages directly determined from three samples ranging from 143.8 to 131.5 Ma. Geochemically, the rhyolites yielded high SiO2 contents (74.44–75.88 wt.%), high total alkalis (K2O + Na2O = 8.50–8.99 wt.%), and low MgO contents (0.16–0.55 wt.%). They displayed strong enrichment in light rare earth elements and depletion in high field strength elements, weakly negative Eu anomalies, A/CNK ratios near unity, and relatively high Nb/Ta ratios. Trace element signatures and incompatible element abundances (Zr + Nb + Ce + Y = 193.2–338.3 × 10−6) are mostly consistent with highly fractionated I-type volcanic rocks, rather than S-type or M-type affinities. The geochemical data suggest that the rhyolites were mainly generated by partial melting of a medium- to high-K basaltic lower crust, with minor crustal assimilation and limited mantle input. Tectonically, Early Cretaceous magmatism in the northern Great Xing’an Range was governed by flat-slab subduction and subsequent rollback of the Paleo-Pacific (Izanagi) plate, while the local E–W-trending rhyolite belt was controlled by pre-existing faults, reflecting localized post-orogenic extension consistent with regional NE-trending volcanic belts. The northwest-to-southeast younging trend records asthenospheric upwelling and enhanced crust–mantle interaction induced by slab rollback. These results highlight the petrogenetic and tectonic evolution of medium- to high-K magmatism along the NE Asian continental margin and improve our understanding of Mesozoic volcanism in the Great Xing’an Range. Full article
(This article belongs to the Special Issue Selected Papers from the 7th National Youth Geological Congress)
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23 pages, 13317 KB  
Article
Geochemical Distribution Characteristics, Traceability, and Health Risk Assessment of Potential Toxic Elements in Granite Weathering Crust-Type Rare Earth Mine and Its Surrounding Areas, Southeast China
by Chenge Ma, Siwen Liu, Qing Sun, Jixin Wei, Chunli Xu, Qiang Xue, Taotao Yan, Shanshan Hou and Manman Xie
Appl. Sci. 2026, 16(3), 1441; https://doi.org/10.3390/app16031441 - 30 Jan 2026
Viewed by 418
Abstract
The Z.D. granite weathering crust rare earth deposit in Ganzhou, China is a world-class resource. In situ leaching extraction may mobilize potentially toxic elements (PTEs) into surrounding soils. This study analyzed nine PTEs (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) in [...] Read more.
The Z.D. granite weathering crust rare earth deposit in Ganzhou, China is a world-class resource. In situ leaching extraction may mobilize potentially toxic elements (PTEs) into surrounding soils. This study analyzed nine PTEs (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) in top soils within and around the mining area. A multi-method approach was employed, integrating geochemical assessment, pollution and ecological risk indices, and probabilistic health risk evaluation via Monte Carlo simulation and source apportionment using Positive Matrix Factorization (PMF) combined with Geographic Information System (GIS) analysis. Results indicated generally low background levels, though with localized Pb enrichment, and an overall low level of pollution and ecological risk. However, for children in nearby areas with prolonged exposure, there was a 9.11% probability of non-carcinogenic risk and a 13.82% probability of carcinogenic risk. PMF-GIS analysis traced PTEs to four sources: natural parent material, industrial emissions, mining/riverine transport, and agriculture. In conclusion, while current soil environmental risks in the Z.D. mining area remain manageable, the study underscores the need to monitor progressive PTE accumulation and children’s health risks. This work provides a scientific basis for targeted soil management and ecological restoration in rare earth mining regions. Full article
(This article belongs to the Special Issue Current Approaches in Applied Geochemistry)
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