Applied Geochemistry最新文献

{"title":"Monazite chemistry for iron sulfide-copper-gold exploration in the Mount Isa Province, Queensland, Australia","authors":"Travis Batch ,&nbsp;Caroline Tiddy ,&nbsp;Adrienne Brotodewo ,&nbsp;David Giles ,&nbsp;Courteney Dhnaram ,&nbsp;Vladimir Lisitsin","doi":"10.1016/j.apgeochem.2025.106674","DOIUrl":"10.1016/j.apgeochem.2025.106674","url":null,"abstract":"<div><div>The chemistry of hydrothermal monazite can be used as an indicator of iron sulfide-copper-gold (ISCG) mineralisation based on a case study of the Kulthor deposit in the Cloncurry District. Monazite associated with mineralisation has elevated La, Nd and S, and a moderately negative chondrite-normalised Eu anomaly, and is typically polycrystalline and intimately associated with pyrite, pyrrhotite and chalcopyrite. Monazite from mineralised and unmineralised rocks can be separated on a plot of Ce versus La + Nd using a line with the equation y = 0.95x. Monazite that is found within unmineralised rocks is enriched in Y, Dy, Th and U relative to mineralised samples and have a strong negative chondrite-normalised Eu anomaly. A plot of Y versus Dy shows two distinct gradients for the monazite analyses, whereby monazite analyses in unmineralised rocks follow the gradient of 0.24 (r² = 0.946), in contrast to mineralisation-associated and proximal monazite analyses which follow a gradient of 0.47 (r² = 0.889). Monazite grains from unmineralised rocks have well defined, jagged grain boundaries and commonly contain inclusions of zircon, apatite, rutile and xenotime. Integration of monazite data from Kulthor with a previous study on the nearby Jericho ISCG deposit allowed development of geochemical discrimination diagrams for ISCG deposits whereby Ca/Th ratios &gt;5 and S/Th ratios &gt;0.1 are indicative of monazite associated with ISCG mineralisation.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106674"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age-dependent cementitious leachate effects on metal and radionuclide sorption to sediments from a subsurface waste-disposal site","authors":"Peng Lin ,&nbsp;Karah Greene ,&nbsp;Wei Xing ,&nbsp;Steven Simner ,&nbsp;Christina Logan ,&nbsp;Richard Henry ,&nbsp;Daniel I. Kaplan","doi":"10.1016/j.apgeochem.2026.106701","DOIUrl":"10.1016/j.apgeochem.2026.106701","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Risk assessment to evaluate long-term disposal for heavy metal and radioactive constituents at the subsurface engineered disposal facilities rely on distribution coefficients (&lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt; &lt;em&gt;=&lt;/em&gt; &lt;em&gt;C&lt;/em&gt;&lt;sub&gt;&lt;em&gt;solid&lt;/em&gt;&lt;/sub&gt;&lt;em&gt;/C&lt;/em&gt;&lt;sub&gt;&lt;em&gt;liquid&lt;/em&gt;&lt;/sub&gt;). Low-level solid and liquid radioactive waste is disposed in the subsurface environment using various cementitious engineered barriers. This study measured &lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt; values to quantify the sorption–including adsorption, absorption, and/or precipitation for multiple metals/radionuclides in subsurface sediments impacted by cementitious leachates representing different cement aging stages, experimentally introduced as Cs(I), Sr(II), Ni(II), Eu(III), Th(IV), U(VI), Cr(VI), and Tc(VII), serving as chemical analogs of different chemical groups. Simulated groundwater (Stage IV) was used as a baseline besides three leachate simulants: freshly made concrete leachate (Stage I), portlandite (Stage II), and calcite (Stage III) to calculate the cementitious leachate impact factor (&lt;em&gt;f&lt;/em&gt;&lt;sub&gt;CementLeach&lt;/sub&gt;), defined as &lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt;-CementLeach/&lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt;-groundwater. Results showed significant changes in sorption between groundwater and leachate simulants. Monovalent cation analog Cs exhibited &lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt; values of 28–2390 L/kg (sandy) and 84–4230 L/kg (clayey), with &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;CementLeach&lt;/sub&gt; up to 62 in sandy sediments impacted by young grout leachate. Divalent cations (Ni and Sr) and trivalent/tetravalent cations (Eu, Th) also showed strong enhancements in high-pH cementitious leachate environments; for example, Eu &lt;em&gt;K&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt; increased from 25 L/kg in Stage IV groundwater to &gt;67000 L/kg in leachates. Tetravalent cation analog Th showed very strong sorption (&gt;10000 L/kg) in young and aged leachates, consistent with prior trivalent cation trends (Eu). Enhanced retention of multivalent cations (e.g., Ni&lt;sup&gt;2+&lt;/sup&gt;, Eu&lt;sup&gt;3+&lt;/sup&gt;, Th&lt;sup&gt;4+&lt;/sup&gt;, and UO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;) in cementitious leachate-impacted sediments reflects not only surface sorption processes but also precipitation under elevated pH conditions, particularly in young grout leachate environments. Such precipitation-driven mechanisms were not evident for Cs&lt;sup&gt;+&lt;/sup&gt;. Across cement aging stages, enhanced (Stage III) and/or reduced sorption (Stage II) can be observed for anionic species CrO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;, while &lt;sup&gt;99&lt;/sup&gt;TcO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;, a key risk driver, displayed minimal sorption and negligible response to cementitious leachates. These results represent the first extensive dataset quantifying cementitious leachate effects on sorption to sediments for different types of cation and anion metal contaminants. It also underscores how the evolution of cementitious barriers reshapes groundwater chemistry, directly influencing the predicted mobil","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106701"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Endolithic environments in hydrothermally altered volcanic rocks from a coastal spring in Baja California, México: Mineralogical interfaces and the search for preserved biosignatures","authors":"Enrique Iñiguez ,&nbsp;Vladimir Mendoza-Lavaniegos ,&nbsp;Thomas G. Kretzschmar","doi":"10.1016/j.apgeochem.2026.106700","DOIUrl":"10.1016/j.apgeochem.2026.106700","url":null,"abstract":"<div><div>Coastal hydrothermal systems provide valuable analog environments for investigating microbial‒mineral interactions and preserving biosignatures under extreme physicochemical gradients. At the Puertecitos intertidal spring in Baja California, México, we conducted an integrated mineralogical, geochemical, and structural analysis of a hydrothermally altered ignimbrite to characterize endolithic microbial habitats and their fossilization potential. Thin section petrography, SEM, XRD, FTIR, and μXRF revealed a vertically zoned substrate, including an unaltered ignimbrite, a weathered alteration fringe, a dark sulfide-rich transition, and a crystalline barite–quartz assemblage. Elemental mapping (Fe, S, Ba, Sr, and As) and principal component analysis highlighted distinct geochemical domains shaped by episodic hydrothermal fluid pulses and seawater mixing. Microtomography (μCT) revealed very low total and open porosities (0.29 % and 0.017 %, respectively) but unexpectedly high permeabilities attributed to interconnected microfractures. SEM imaging revealed abundant and morphologically diverse microbial biosignatures, which were predominantly preserved in the crystalline and transition zones through rapid silicification and barite precipitation. These microenvironments, which are structured by mineral precipitation and permeability anisotropy, provide localized redox gradients and nutrient sources that support the preservation of chemolithotrophic endolithic communities. Our results demonstrate that hydrothermal fluid dynamics, mineral precipitation, and rock microstructure govern the habitability and fossilization potential of volcanic substrates in geothermal settings (temperature ranges from 32.7 to 73.7 °C and pH 6.7–8.1). The Puertecitos system offers a compelling terrestrial analog for studying microbial survival, mineral-driven weathering, and biosignature preservation on early Earth and Mars, emphasizing the importance of mineralogical interfaces and hydrothermal processes in structuring habitable niches in extreme environments.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106700"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting differentiated achondrite parent bodies through machine learning: Insights from major element","authors":"Zhao Yan ,&nbsp;Jin-Ting Kang ,&nbsp;Weibiao Hsu ,&nbsp;Fang Huang","doi":"10.1016/j.apgeochem.2026.106687","DOIUrl":"10.1016/j.apgeochem.2026.106687","url":null,"abstract":"<div><div>Rapid and accurate identification for parent bodies of achondrites is crucial for planetary science research. In this study, we examined the performance of machine learning algorithms using bulk rock major element compositions to classify the origins of achondrites derived from the Moon, Mars, and asteroid 4 Vesta. Literature data on lunar basalts and anorthosites, Martian meteorites, and HED meteorites potentially originating from Vesta, are compiled and cleaned. Multiple machine-learning models were applied including a Tabular Prior-data Fitted Network (TabPFN) and six classical models including Decision Tree, Gradient Boosting, Support Vector Machine, Random Forest, K-Nearest Neighbors, and Multilayer Perceptron. All models demonstrate robust classification performances achieving over 95 % accuracy for the Test Set. Particularly, the K-Nearest Neighbors and TabPFN models achieve an accuracy exceeding 99 %. This study presents a new, automated method in identifying the parent body of achondrites through bulk rock major element data. While these models perform well, further analysis of feature importance is needed to provide deeper insights into the underlying geochemical controls, ensuring the method complements traditional approaches such as petrography and isotope analysis. To facilitate the broader use by meteorite collectors, cosmochemistry community and enthusiasts, a web interface has been developed to quickly apply this technique: <span><span>https://geo-cosmo-chemistry.shinyapps.io/meteorites_classification/</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106687"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exceptional methylmercury bioaccumulation in rice grain from karst region with high geological background","authors":"Langfei Wei ,&nbsp;Shaochen Yang ,&nbsp;Ruolan Li ,&nbsp;Rasheed Mohammed Abdul ,&nbsp;Yanxin Hu ,&nbsp;Haiyu Yan ,&nbsp;Baolin Wang ,&nbsp;Haiyan Hu ,&nbsp;Ping Li","doi":"10.1016/j.apgeochem.2026.106695","DOIUrl":"10.1016/j.apgeochem.2026.106695","url":null,"abstract":"<div><div>Rice consumption poses significant methylmercury (MeHg) exposure risks for residents in mercury (Hg) contaminated areas, yet the corresponding health risks in high geological background (HGB) regions remain overlooked. Here, we systematically evaluated rice Hg levels across two HGB karst regions (DH and XL) and a general background area (XN), and compared them with a Hg mining area (WWR). Despite soil total Hg (THg) concentrations in all study areas being below Chinese risk screening value (0.6 mg/kg, 6.5 &lt; pH ≤ 7.5) and significantly lower than those in WWR, DH rice exhibited alarming THg levels (21.8 ± 13.1 ng/g, n = 131), with 48.5 % exceeding Chinese safety limit (20 ng/g). This was much higher than those from XL (3.26 ± 1.23 ng/g, n = 140), XN (1.91 ± 0.68 ng/g, n = 138), and even in WWR (14.2 ± 6.9 ng/g, n = 24). Furthermore, DH exhibited remarkably elevated MeHg bioaccumulation factors (BAFs) for rice grains (27.3 ± 14.6, n = 25) compared to XL (1.40 ± 1.00, n = 25) and WWR (7.88 ± 6.93, n = 24). Principal component analysis (PCA) integrated with MeHg BAFs and translocation factors (TFs) revealed exceptional MeHg bioaccumulation capacity in DH rice, predominantly attributed to elevated MeHg uptake through rice root system. Our findings highlight a potential underestimation of Hg levels in rice from HGB regions, and propose inhibiting root uptake from soil as a viable strategy to mitigate Hg accumulation in rice.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106695"},"PeriodicalIF":3.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of tectonics and fluid circulations on shale gas isotope geochemistry – A case study of the Rietheim Member at the Mont Terri anticline (Switzerland)","authors":"Catherine Lerouge ,&nbsp;Michaela Blessing ,&nbsp;Marie Bonitz ,&nbsp;Ana-Maria Fernández ,&nbsp;Christine Flehoc ,&nbsp;Nicolas Maubec ,&nbsp;Guillaume Wille ,&nbsp;David Jaeggi ,&nbsp;Michael Kühn","doi":"10.1016/j.apgeochem.2026.106696","DOIUrl":"10.1016/j.apgeochem.2026.106696","url":null,"abstract":"<div><div>In the framework of the hydrological survey of the Mont Terri anticline (Mont Terri rock Laboratory in the Folded Jura, Switzerland), a 58 m-deep borehole (BHS-1) was drilled through the Jurassic low permeability shale sequence. Dedicated sampling was carried out to characterize gases within a 13 m-thick unit of organic matter-rich Early Jurassic Rietheim black shales and adjacent units, including the underlying Beggingen aquifer. A cone-in-cone calcite, observed at the bottom of the black shale, as identified as an indicator of oil-window conditions and records a maximal burial temperature of ∼80–90 °C. Two fracture zones within the black shales, marked by calcite infillings, provide evidence for at least two episodes of water paleocirculations: (1) an early circulation between fractures at the top of black shales and the Main Fault, and (2) a later circulation between fracture zones within the black shales and the lower Beggingen aquifer. Gas migration was investigated within the complex geological context of regional uplift, Jura folding and thrusting, and associated water flows. Alkane data reveal a partial carbon isotope reversal of thermogenic gases within the black shales between the two fracture zones, strongly suggesting alkane migration linked to the second water paleocirculation episode.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106696"},"PeriodicalIF":3.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfide mineral weathering in century-old waste rock","authors":"Andrew Hicks,&nbsp;Colleen O. Harper,&nbsp;Richard T. Amos","doi":"10.1016/j.apgeochem.2026.106697","DOIUrl":"10.1016/j.apgeochem.2026.106697","url":null,"abstract":"<div><div>The weathering of sulfide minerals in mining waste-rock piles can release acidity and metals to the environment, potentially for many decades. Although the extent and mechanisms of weathering have been investigated in several studies, most have been done on relatively young waste rock and there is a lack of information on the long-term weathering in these systems. The Ore Chimney site is an abandoned prospecting property with a ∼10 kiloton waste-rock pile that has been in place for ∼100 years. This study provides a detailed mineralogical investigation of waste-rock samples from three vertical profiles obtained in trenches dug through the 5-m depth of the pile. Analysis included optical microscopy, scanning electron microscopy with energy dispersive X-Ray spectrometry, powdered X-ray diffraction, total carbon and sulfur analysis, and solid-phase digestions followed by inductively coupled plasma atomic emission and mass spectrometry on both fine (&lt;0.5 mm) and coarse (0.5–2 mm) fractions of sieved waste rock. The results show relatively uniform weathering throughout the waste-rock pile, and in the coarse and fine waste-rock fractions, with preferential weathering of sulfide minerals in the order sphalerite &gt; galena &gt; pyrite &gt; chalcopyrite. Most sphalerite grains showed 10–30 % weathering of the exposed mineral surfaces, while the other sulfides showed no weathering in many of the grains. This study shows that despite ∼100 years of sub-aerial exposure, sulfide weathering continues, with preferential weathering of sphalerite limiting the oxidation of the other sulfide minerals and the release of acidity, while preserving the buffering capacity of carbonate minerals.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106697"},"PeriodicalIF":3.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting the kinetics of Cu release and transport in contaminated soils in the field","authors":"Liang Dong ,&nbsp;Rong Li ,&nbsp;Wenxia Wang ,&nbsp;Zhifang Xiao ,&nbsp;Zezhen Ren ,&nbsp;Qianting Ye ,&nbsp;Zhenqing Shi","doi":"10.1016/j.apgeochem.2026.106698","DOIUrl":"10.1016/j.apgeochem.2026.106698","url":null,"abstract":"<div><div>Accurately predicting heavy metal release from contaminated soils remains challenging because of heterogeneous sorption sites, dynamic organic-matter turnover, and transient hydrological forcing. Here we develop a unified multi-process kinetics model that couples multi-site adsorption–desorption, vertically resolved dissolved organic carbon (DOC) dynamics, and water flow–solute transport to simulate copper (Cu) release in two contaminated field sites during rainfall events. We further accelerate the numerical solver with a machine-learning surrogate model, achieving more than 100-fold speed-up. Rainfall–evaporation experiments at two Cu-contaminated soils with contrasting textures and contamination levels showed that less than 5 % of total Cu was labile, and that soil organic matter dominated Cu binding. The model reproduced depth-resolved dissolved Cu profiles with symmetric mean absolute percentage errors of 26–30 %, by capturing rainfall-driven dilution, adsorption–desorption kinetics, and DOC-mediated mobilization. Our results show that short-term Cu mobility is controlled primarily by its labile fraction rather than total concentration, and that coupling carbon cycling with hydrodynamics is essential for field-scale predictions. This transferable modeling framework enables mechanistic and site-specific forecasts of heavy-metal fate under diverse and changing environmental conditions.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106698"},"PeriodicalIF":3.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering critical factors of rare metal mineralization: New insights from machine learning analysis of zircon geochemistry data","authors":"Yunfei Zhang ,&nbsp;Lei Liu ,&nbsp;Sun Jiandong ,&nbsp;Heng Liu ,&nbsp;Chuangye Zhang ,&nbsp;Zhou Weijian","doi":"10.1016/j.apgeochem.2026.106686","DOIUrl":"10.1016/j.apgeochem.2026.106686","url":null,"abstract":"<div><div>Rare metal (Li, Be, Nb, Ta, Rb, Cs) deposits, one of the world's primary sources of lithium, have seen rapidly growing demand due to the accelerated development of strategic emerging industries. The formation of these deposits is closely associated with magmatic-hydrothermal processes that produce highly fractionated pegmatites. However, post-mineralization processes can obscure geochemical signatures recorded in rocks and minerals, inevitably introducing uncertainty when using conventional discrimination diagrams to assess the mineralization potential of pegmatites. To address this uncertainty, we developed a novel semi-supervised machine learning (ML) approach that integrates XGBoost and BPNN (backpropagation neural network) in parallel fusion. This method leverages zircon trace element data to decipher critical mineralization indicators from single-mineral geochemical signatures, aiding in the effective evaluation of pegmatite mineralization potential. To ensure model transparency and interpretability, we employed Shapley Additive explanations (SHAP) for model interpretation. The results revealed the following: (1) high δCe-high U-high Eu values represent a diagnostic signature of granitic zircons; (2) high δEu-high Yb-high Pr values are characteristic of pegmatitic zircons; while (3) high Tb-high Nd-high Pr values comprise the key discriminant of zircons within mineralized pegmatites. The parallel-fused XGBoost + BPNN model demonstrates robust capability in differentiating between granite- and pegmatite-hosted zircons and zircons within mineralized and barren pegmatites, therefore providing a reliable tool for assessing regional rare metal mineralization potential.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106686"},"PeriodicalIF":3.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of mixing pattern on oil-mineral aggregation and oil removal in coastal waters: A lab-scale study","authors":"T.R. Akshaya ,&nbsp;Ethayaraja Mani ,&nbsp;K. Murali ,&nbsp;Jan Schwarzbauer","doi":"10.1016/j.apgeochem.2025.106676","DOIUrl":"10.1016/j.apgeochem.2025.106676","url":null,"abstract":"<div><div>Ensuing an oil spill, oil-mineral aggregates (OMAs) are formed due to the aggregation of dispersed oil droplets with suspended sediment particles such as clay minerals. This process mainly occurs in coastal areas where suspended sediments interact with the oil droplets formed by the turbulent action of the waves. To better understand the effect of the mixing patterns on OMA formation, we study the formation and oil removal percentage (ORP) of OMAs under two mixing conditions: (1) orbital shaker and (2) magnetic stirrer, representing inward and outward directional flow patterns, respectively, at similar mixing energies. It impacts OMA formation by altering droplet-particle collision frequency and the balance between aggregation and shear-induced breakup. The experiments are conducted using bentonite and kaolinite clay at various concentrations. The kinetics of ORP are analysed using a logistic saturation curve, and the kinetic parameters are determined. The findings of the study indicate that the ORP is higher for mixing conditions of the orbital shaker, which causes the fluid to move along the container wall creating a swirling motion. The fastest removal occurred at a concentration of 1 g/L for kaolinite OMAs. The maximum ORP was observed to be 70 % for kaolinite and 65 % for bentonite. This work establishes a clear understanding of the effect of the mixing flow directionality on ORP and OMA formation under various concentrations. These findings provide valuable insights into the natural attenuation of dispersed oil in coastal environments and improve the mitigation of the impacts of oil spills.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106676"},"PeriodicalIF":3.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}