Applied Geochemistry最新文献

{"title":"Rock weathering characteristics and carbon sink in the Liujiang Basin, North China","authors":"Xiangbin Zeng ,&nbsp;Zhaoliang Song ,&nbsp;Zhixue Xing ,&nbsp;Jing Meng ,&nbsp;Xijun Wang ,&nbsp;Shuyan Liu ,&nbsp;Delin Song ,&nbsp;Zimin Li ,&nbsp;Jianwu Li ,&nbsp;Aiquan Shi ,&nbsp;Jiahao Qin ,&nbsp;Changxun Yu ,&nbsp;Tony Vancov ,&nbsp;Yuntao Wu ,&nbsp;Hailong Wang","doi":"10.1016/j.apgeochem.2025.106435","DOIUrl":"10.1016/j.apgeochem.2025.106435","url":null,"abstract":"<div><div>Global greenhouse gas emissions are on the rise, exacerbating warming. Rock weathering significantly influences the carbon cycle and climate. There are differences in the consumption of atmospheric CO₂ during the weathering process of different rocks. The Liujiang Basin, typical strata from various geological periods in North China, holds significant representative importance in assessing rock weathering and carbon sink. In this regard, we collected two sample series during both high-water and low-water periods and assessed the chemical weathering rates based on the chemical and isotopic compositions of the water, as well as a forward modeling strategy which is based on mass balance. The forward modeling analysis illustrated that rock weathering contributed the most to the total cations (81.62 %–97.13 %, with an average of 92.89 %), with carbonate rock weathering contributing the most (23.80 %–77.12 %, with an average of 54.61 %), followed by silicate rock weathering (3.27 %–61.19 %, with an average of 21.17 %) and evaporite dissolution (5.93 %–26.52 %, with an average of 17.11 %). The Sr concentrations in the river water ranged from 0.63 to 21.34 μmol L⁻¹, while Sr isotope ratios (⁸⁷Sr/⁸⁶Sr) had a 101 % variation scale. The δ¹³C values ranged from −14.73 to −7.06 ‰. Quantitative analysis further illustrated that atmospheric precipitation, carbonate, and evaporite inputs collectively accounted for 64.15 % (42.12 %–97.61 %) of total dissolved Sr, while silicate rocks accounted for 35.85 % (2.39 %–57.88 %). Overall, the silicate and carbonate weathering rates in the Liujiang Basin were 6.35 t km⁻²·a⁻¹ and 22.20 t km⁻²·a⁻¹, respectively. The atmospheric CO₂ consumption flux from silicate and carbonate weathering was 2.27 × 10⁵ mol km⁻²·a⁻¹ and 2.56 × 10⁵ mol km⁻²·a⁻¹, respectively. Considering plant biomass management, the carbon sinks of silicate and carbonate rocks in the Liujiang Basin can increase by about 27 % and 4 %. The rock weathering CO₂ consumption flux in the Liujiang Basin matches or exceeds other major Chinese rivers, highlighting the importance of small watersheds in carbon sequestration.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106435"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139002","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":"Dissolved organic matter sources in urban outfall water before and during rainfall, indicated via its fluorescence fingerprinting","authors":"Haojie Yin ,&nbsp;Tao Huang ,&nbsp;Bo Wang ,&nbsp;Yingying Zhang ,&nbsp;Jiawei Hu ,&nbsp;Linlin Zhu ,&nbsp;Kaining Chen","doi":"10.1016/j.apgeochem.2025.106447","DOIUrl":"10.1016/j.apgeochem.2025.106447","url":null,"abstract":"<div><div>Pollution source identification is the key foundation of urban river water quality management. In this study, fluorescence fingerprinting was employed to analyze changes in dissolved organic matter (DOM) sources in urban river outfalls P1–P3 in Hefei City, China, before and during a rainfall event. The water quality of the outfalls varied before and during rainfall, with an apparent dilution in P2 and a combined effect of urban non-point runoff and dilution in P3. The fluorescent components of the DOM in the outfall water were fulvic acid-like substances C1, terrestrial humic-like substances C2, and tryptophan-like substances C3. The dominant C1 in P1 was diluted by rainfall runoff, decreasing the total fluorescence intensity (F_T) of the DOM. The increased F_T and proportion of C1 + C2 in P2 during early rainfall indicated runoff inputs, whereas those in P3 increased and decreased thereafter, suggesting that rainfall led to an influx of domestic sewage. Fluorescence fingerprinting analysis indicated that the DOM in P1 originated primarily from rainwater and domestic wastewater treatment plant (WWTP) effluent. The DOM in P2 originated from domestic WWTP effluent pre-rainfall, rainwater, and domestic WWTP effluent during early rainfall and urban non-point runoff during later rainfall, whereas that in P3 originated from domestic sewage before and during early rainfall and urban non-point runoff during later rainfall. Identifying sources of pollution provides a basis for urban outfall and river water quality management before and during rainfall events.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106447"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154962","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":"Igneous intrusion effect on the geochemistry of Late Miocene Onnagawa mudstone: implication on the atypical hydrocarbon generation of Akita Basin, Japan","authors":"Barry Majeed Hartono,&nbsp;Shun Chiyonobu,&nbsp;Takuto Ando","doi":"10.1016/j.apgeochem.2025.106448","DOIUrl":"10.1016/j.apgeochem.2025.106448","url":null,"abstract":"<div><div>This study investigated the physio-chemical changes in organic matter, from micro-to macromolecular scale, due to rapid heating from igneous intrusion, particularly if intrusion emplacement occurred syn-contemporaneously with the organic matter deposition. The Neogene siliceous mudstone of the Onnagawa Formation in the Akita Basin is a suitable interval for this study, as subvolcanic and volcanic rocks were found within the formation. Hence, eight cutting samples of the formation from the Yabase well were subjected to Rock-Eval pyrolysis analysis, while three samples near the intrusion body and one unintruded sample were then selected for further biomarker analysis. Generally, kerogen, represented by Tmax, and biomarker proxies respond to the extreme thermal stress from intrusion. While the background Tmax is very low in our well (Tmax&lt;430 °C), this parameter is significantly elevated in the intrusion zone, accompanied by an increasing production index (PI) alongside with reduced TOC and hydrogen index (HI). In contrast, slight changes, including reversal trend, in several maturity-related saturate biomarker ratios, such as C₂₃ tricyclic terpanes (TT) βα/αα, C₂₄ tetracyclic terpanes/C₂₃ TT, Ts/(Ts + Tm), C₂₉ and C₃₀ moretanes/hopanes, C₃₁–C₃₅ homohopanes (HH) 22S/(22S + 22R), and C₂₉ steranes 20S/(20S + 20R) were observed near the intrusion proximity. These phenomena are related to three major factors, which are kerogen-related generation, failed isomerization, and thermal degradation. Rapid heating from intrusion is insufficient to exhibit isomerization reaction, while kerogen, which is more thermally resistant, absorbs the heat and generates bitumen, including more immature isomers. Furthermore, this generated bitumen correlates with the produced oils in the area, which also inherit low maturity characteristics. Thus, it becomes evident that igneous intrusion could activate the atypical petroleum system in one basin, despite the source rock being deposited concurrently with or immediately after the intrusion event.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106448"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195068","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":"The influence of thermo-mineral and seawater on the mineralogy and chemistry of residual smectitic soils from Alentejo, Portugal: a case study","authors":"A. Valente,&nbsp;F. Rocha,&nbsp;S. Andrejkovicová,&nbsp;D. Terroso,&nbsp;C. Sequeira,&nbsp;E. Ferreira da Silva","doi":"10.1016/j.apgeochem.2025.106446","DOIUrl":"10.1016/j.apgeochem.2025.106446","url":null,"abstract":"<div><div>Peloid is a natural product developed during the maturation process between a clay material and water and is used in health and wellness centres due to its mineralogical, physiochemical and biological properties. However, the potential therapeutic value of clays in Portugal has not been fully investigated. Therefore, the main objective of this research is to identify the effects of two mineralized waters: thermo-mineral water (sulphurous and hydroxylated water abundant in chloride ions, sodium and calcium) and seawater, on three residual soils from Alentejo, from a morphological, mineralogical and chemical perspective. The peloids morphology is more homogeneous than the residual soils, and the particle size decreases during the maturation process. Thermo-mineral water enriched the peloids in smectite (58–76 %), while seawater newly formed Na-minerals (decreasing smectite contents to 39–54 %). Smectite is essentially montmorillonite, although there is nontronite and beidelite. The residual soils and peloids have a silicilastic composition (32.23–52.85 %), between 14.22 and 20.53 % of Al₂O₃, and besides smectite, the mineralogical composition is composed of salts (only in seawater peloids), feldspars, iron oxides, carbonates, and quartz. Morphology and mineralogy enhance the influence of waters in peloids properties and suggest that this samples have potential therapeutic value. Furthermore, physical-chemical, rheological, thermal and biological analysis are needed to support these findings.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"188 ","pages":"Article 106446"},"PeriodicalIF":3.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131290","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":"Differentiation of groundwater flow patterns in multiple karst systems in a covered karst basin in China through hydrochemistry, stable isotopes, and 222Rn","authors":"Liqiong Wei ,&nbsp;Fang Guo ,&nbsp;Guanghui Jiang ,&nbsp;Fan Liu ,&nbsp;Zhijie Li","doi":"10.1016/j.apgeochem.2025.106436","DOIUrl":"10.1016/j.apgeochem.2025.106436","url":null,"abstract":"<div><div>Groundwater in covered karst basins is abundant, but the thick soil cover and the lack of distinct surface karst features complicate the understanding of subsurface flow. This study integrates physicochemical parameters, stable hydrogen and oxygen isotopes, and the radon isotope (²²²Rn) to characterize groundwater flow within local, intermediate, and regional karst water systems in a covered basin in South China. The aims are to distinguish differences among these systems, examine radon concentration variations at their outlets, and assess the potential of ²²²Rn in identifying groundwater flow characteristics. Groundwater in the regional karst system is characterized by the most extensive water-rock interaction, extended flow paths and residence time, minimal anthropogenic influence, and slow, fracture-dominated flow in the final stages of flow paths. In contrast, local and intermediate karst systems are more responsive to external changes, with rapid conduit flow primarily occurring in their terminal sections. Owing to the short residence time and flow paths, radon is rapidly transported to the discharge points, resulting in higher concentrations in groundwater from local karst systems compared to intermediate and regional systems, which have longer residence time. Similar to hydrochemical and isotopic trends, radon concentrations in local and intermediate systems fluctuate more than in regional systems, suggesting rapid flow in the terminal sections of both. Radon activity can qualitatively identify flow characteristics in karst aquifers. The integration of hydrogeochemical, stable isotopes, and ²²²Rn data provides a comprehensive understanding of flow patterns linked to aquifer structures and insights into radon behavior in karst water systems.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"188 ","pages":"Article 106436"},"PeriodicalIF":3.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131287","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":"Distribution and leachability of heavy metals from lead-zinc tailings with different degrees of chemical weathering in the Qinling Mountains","authors":"Shentao Hu ,&nbsp;Xiaohu Xiong ,&nbsp;Xuan Li ,&nbsp;Meixia Wang ,&nbsp;Dongdong Xu ,&nbsp;Weijian Zhou","doi":"10.1016/j.apgeochem.2025.106434","DOIUrl":"10.1016/j.apgeochem.2025.106434","url":null,"abstract":"<div><div>The Qinling Mountains in Shaanxi Province are one of China's most significant ecological reserves, but many lead-zinc tailings have been produced during decades of mining development. The heavy metals in these lead-zinc tailings pose a severe pollution risk to the surrounding areas. However, the vertical distribution, leaching behaviour and ecological risk of heavy metals in these tailings remain unclear. A lead-zinc tailings profile from the southeast foot of the Qinling Mountains was studied. The particle size, chemical composition, mineralogy, micromorphology, Nemerow pollution index and leaching behaviour were analysed. The results showed that the lead-zinc tailings profile had an intermediate chemical weathering layer (depth 0–70 cm) and an incipient chemical weathering layer (depth 70–100 cm). Quartz and muscovite were the main minerals. The intermediate chemical weathering layer was more enriched in Cr and Pb, while the incipient chemical weathering layer was more enriched in Cd and Zn. The final leaching concentrations of Cr, Cd, Zn and Pb in the incipient and intermediate chemical weathering layers after 50 days were very similar, at 0.27–0.36, 0.60–0.81, 6.93–9.03 and 7.81–10.47 mg L⁻¹, respectively. However, the average leaching efficiency was the reverse. Calcite and chemical weathering intensity may have been connected to this. The lead-zinc tailings were highly polluted, with Pb, Zn, Cd and As being the main pollutant elements. In summary, this study provides new insights for controlling heavy metal migration and mitigating environmental hazards in existing lead-zinc tailings ponds in the Qinling Mountains.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106434"},"PeriodicalIF":3.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203286","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":"Indication of triple oxygen isotopes to replenishment mechanisms and evaporation processes in Yongding River Basin, North China","authors":"Yaxin Zhu ,&nbsp;Guilin Han ,&nbsp;Di Wang ,&nbsp;Shitong Zhang ,&nbsp;Xi Gao","doi":"10.1016/j.apgeochem.2025.106427","DOIUrl":"10.1016/j.apgeochem.2025.106427","url":null,"abstract":"<div><div>Urban rivers are important water sources for surrounding agglomerations. Understanding their hydrological processes is crucial for the sustainable water resource development. However, driven by societal demands, extensive human projects to rivers have introduced uncertain consequences for the water cycle in the basin. Therefore, employing the advanced triple oxygen isotopes technique and correlation analysis, the study examined the effects of human intervention on urban river hydrology in Beijing-Tianjin-Hebei region. The results illustrated that the average values of δ²H, δ¹⁸O and δ¹⁷O were at a high level, which effectively reflect the influence of human activities. In conjunction with previous studies, the supplementary effects of anthropogenic water sources and natural replenishment on river discharge were investigated. Besides, the additional evaporation caused by artificial water retention was quantified by using the isotope model. The results elucidated that Guanting Reservoir caused 8.7 % evaporation across the river, and a substantial volume of agricultural water also promoted the evaporation of local river sections. Overall, the study reveals the triple oxygen isotopes signatures in urban rivers, deeply explores and quantifies the effect of anthropic activities on the water cycle process, offering a scientific foundation for the continuable exploitation of regional water resources.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106427"},"PeriodicalIF":3.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154963","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":"Origin of composite fibrous carbonate veins in Middle Jurassic ultra-low-ash coal, Ordos Basin, China: Insights on the interaction between organic carbon and inorganic carbonates after peat burial","authors":"Jintian Zheng ,&nbsp;Shifeng Dai ,&nbsp;Victor P. Nechaev ,&nbsp;David French ,&nbsp;Ian T. Graham ,&nbsp;Na Wang ,&nbsp;Pan Yang ,&nbsp;Shuai Kang ,&nbsp;Mengda Yao ,&nbsp;Yang Liang","doi":"10.1016/j.apgeochem.2025.106430","DOIUrl":"10.1016/j.apgeochem.2025.106430","url":null,"abstract":"<div><div>Valuable geological information on coal is contained within both the organic and inorganic constituents. Buried organic matter and precipitated carbonate minerals, as key elements of the lithospheric carbon reservoir, raise questions about whether their co-occurrence in coal is coincidental or reflects an underlying connection. Authigenic carbonate minerals in coal exhibit diverse species (e.g., siderite, calcite, and the ankerite-dolomite series) and morphologies (e.g., coal balls; nodules; and cell-, cleat- and fracture-filling forms), reflecting various formation processes during coalification. Fibrous carbonate veins in black shales consist of elongated calcite crystals with large aspect ratios (a rare calcite habit), and are associated with hydrocarbon fluid activity. However, the identification, formation mechanism, and material sources of fibrous carbonate veins within coal remains unclear. To resolve this problem, detailed petrographic, mineralogical, and geochemical analyses were conducted on the middle Jurassic No. 2(2) coal of the Ordos Basin, China, including stable isotopic analysis of carbon and oxygen in composite carbonates excluding siderite. The No. 2(2) coal seam is classified as an ultra-low-ash, super-low-sulfur, and high volatile B bituminous coal, according to the Chinese national standards GB/T 15224.1-2018, GB/T 15224.2-2021, and ASTM Standard D388-23, respectively. It contains abundant fusinite and semifusinite fragments dispersed in collodetrinite. Compared with average world coals, only Sr in the coal is slightly enriched. The carbonates in the coal (33.5 %; low temperature ash basis) consist of calcite, ankerite, and siderite. The values of <em>δ</em>¹³C_VPDB and <em>δ</em>¹⁸O_VPDB associated with composite carbonate veins (calcite and ankerite) range from −34.87 ‰ to −11.43 ‰ and from −14.66 ‰ to −10.84 ‰, respectively. Two types of high-ash yield intervals (Si-rich and Ca-rich) were identified within the low-ash coal seam. The Si-rich benches are attributed to the influx of Si–Al-rich fluids during peat accumulation. Composite carbonate veins, which formed during coalification, represent another source for inorganic matter in high-ash intervals (Ca-rich). Optical and electron microscope observations, together with carbon-oxygen isotopic analyses, indicate that overpressurised fluids from coal maturation and methane oxidation led to <em>in situ</em> coal fracturing, followed by the formation of composite fibrous carbonate veins and crack-seal structures in low-ash coal. Based upon these results, a model for the formation of fibrous carbonate veins within low-ash coal from the Cuijiagou mine is proposed to facilitate an understanding of the carbon transformation from organic matter to minerals after peat burial.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"188 ","pages":"Article 106430"},"PeriodicalIF":3.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131289","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":"Machine-learning applications for magmatic–hydrothermal systems: Quartz trace-element insights into ore deposits","authors":"Denghui Zhu ,&nbsp;Jiajie Wang ,&nbsp;Tatsu Kuwatani ,&nbsp;Noriyoshi Tsuchiya","doi":"10.1016/j.apgeochem.2025.106431","DOIUrl":"10.1016/j.apgeochem.2025.106431","url":null,"abstract":"<div><div>Magmatic–hydrothermal activity is critical in ore genesis, as it forms a variety of economically significant ore deposits. Quartz chemistry is key to identifying the types and origins of such deposits; however, conventional analytical methods that use binary/ternary quartz trace-element plots are insufficient for elucidating the full complexity of quartz chemistry. To address this limitation, machine learning is applied to analyze high-dimensional quartz chemistry and improve the identification accuracy. We compiled 8710 quartz samples from a range of geological environments including various host rocks and ore deposits derived from I-, S-, and A-type magmas, and examined 18 trace elements. We developed two approaches—eXtremely Greedy tree Boosting-Recursive Feature Elimination-SHapley Additive exPlanations (XGBoost-RFE-SHAP), and Principal Component Analysis-Uniform Manifold Approximation and Projection (PCA-UMAP)—to discriminate these geological environments based on quartz trace elements. XGBoost-RFE-SHAP achieved highly accurate discrimination and identified key quartz trace elements. B, Ti, P, Li, Ge and Al are key to identifying I-, S-, and A-type parental magmas. For rocks and ore deposits related to I-type magma, key discriminators include Ti, Ge, Al, Li, Sb, and P; for S-type magma, Ge, P, Ti, Al, Li, and B; and for A-type magma, Ti, P, K, Al, Rb, and As. PCA-UMAP generated plots for classifying rocks and ore deposits, revealing quartz trace-element patterns across various geological environments. This integrated approach enhances the understanding of magmatic–hydrothermal evolution and offers a powerful tool for identifying economically viable deposits, with potential applications in diverse geological settings.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106431"},"PeriodicalIF":3.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139003","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":"Regional geochemical survey of Canadian Arctic sediments: insights into provenance, sediment dynamics and trace metal enrichment","authors":"Camille Brice ,&nbsp;Jean-Carlos Montero-Serrano ,&nbsp;Richard Saint-Louis","doi":"10.1016/j.apgeochem.2025.106432","DOIUrl":"10.1016/j.apgeochem.2025.106432","url":null,"abstract":"<div><div>Major and trace element contents, grain size distribution and total organic carbon contents were measured in 141 marine surface and terrestrial sediment samples to study modern sediment dynamics in the Canadian Arctic (CA) and to provide an assessment of metal enrichment for V, Zn, Mn and Fe. Samples were collected from different areas between Baffin Bay and the Beaufort Sea during the ArcticNet 2016–2022 expeditions onboard the Canadian Coast Guard icebreaker Amundsen. Geochemical data combined with multivariate statistical analyses allowed the division of the CA into three chemical clusters (CC) and four regional provinces. Central CA (CC#1) and southeastern CA (CC#2) are mainly composed of relatively coarse sediments rich in detrital carbonates (Ca, Mg) and siliciclastic elements (Si, K, Zr), respectively, reflecting coastal erosion of surrounding land (e.g., Victoria Island, Baffin Island) and transport of sediment-laden sea ice. The sediments of CC#3, comprising western and eastern CA, are characterized by organic carbon and Fe–Mn oxyhydroxides. Western CA, which is also characterized by fine-grained aluminosilicates, is influenced by the Mackenzie River discharge, while eastern CA is shaped by polynyas and glacial erosion. The highest concentrations of V and Zn are recorded in the western CA. Over the whole region, significant positive correlations of Al with Zn, V and Fe suggest that lithogenic-derived inputs influence the distribution of these metals in sediments from the CA and that Fe oxides represent the main carrier phase. In western CA, Mn displays positive but weaker relationships with Al and Fe, suggesting a mixed source of Mn oxyhydroxides linked to both detrital fractions and authigenic processes near the sediment-water interface. High terrestrial Mn oxyhydroxide inputs from the Mackenzie River are remobilized and transported to areas with lower oxygen consumption in sediment, i.e., the Amundsen Gulf and Banks Island coasts, which leads to surface sediment enrichment in Mn. The enrichment factor and the geo-accumulation index, two pollution indices commonly used for identifying anthropogenic metal inputs, were also studied to evaluate their suitability in the context of this study. Discrepancies from the normalization of metals with a geochemical background and a normalizing element revealed that pollution indices should be used with caution. Overall, according to the pollution indices and the regional survey, the surface sediments of the CA show minor enrichment in trace metals and thus present natural concentrations relative to regional background values.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"189 ","pages":"Article 106432"},"PeriodicalIF":3.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154964","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}