Applied Geochemistry最新文献

{"title":"Hydrochemistry of a coastal sedimentary basin: evidence from the Lower Kutai Basin, Indonesia","authors":"Arifin ,&nbsp;Richard G. Taylor ,&nbsp;Mohammad Shamsudduha ,&nbsp;Agus M. Ramdhan ,&nbsp;Irwan Iskandar ,&nbsp;Taat Setiawan ,&nbsp;Munib Ikhwatun Iman ,&nbsp;Riza Arian Noor","doi":"10.1016/j.apgeochem.2025.106496","DOIUrl":"10.1016/j.apgeochem.2025.106496","url":null,"abstract":"<div><div>Groundwater is a vital freshwater resource in coastal regions, where 38 % of the global population currently resides. The hydrochemistry of abstracted groundwater in low-lying deltaic regions can pose a risk to human health, especially where monitoring of groundwater quality is limited. This study investigates new evidence of the hydrochemistry of shallow (depths of &lt;250 m) groundwater in the Lower Kutai Basin (LKB) where Indonesia's new capital, Nusantara, is situated. Shallow groundwater is predominantly (67 out of 73 samples) fresh with a median total dissolved solids of 197 mg/L and hydrochemical facies are dominated by the bicarbonate anion. In this coastal sedimentary basin, high concentrations of iron (median = 5.4 mg/L) and manganese (median = 138 μg/L) that exceed WHO drinking-water guidelines reflect widespread reducing conditions in shallow groundwater, promoted by sluggish flow under low hydraulic gradients (primarily &lt;0.002). Stable isotope ratios (δ¹⁸O, δ²H) indicate that inland fresh groundwater, traced to heavy rainfall, becomes isotopically heavier and more saline toward the coast. Although the hydrochemical conditions favoring arsenic mobilization mirror those of Asian megadeltas, arsenic concentrations in the shallow groundwater of the LKB are generally low (median = 0.5 μg/L).</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106496"},"PeriodicalIF":3.1,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588341","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":"Comparative analysis of sea salt species in snow samples from Svalbard using ICP-QMS and IC techniques","authors":"Azzurra Spagnesi ,&nbsp;Elena Barbaro ,&nbsp;Warren Raymond Lee Cairns ,&nbsp;Matteo Feltracco ,&nbsp;Federico Scoto ,&nbsp;Andrea Gambaro ,&nbsp;Carlo Barbante ,&nbsp;Andrea Spolaor","doi":"10.1016/j.apgeochem.2025.106492","DOIUrl":"10.1016/j.apgeochem.2025.106492","url":null,"abstract":"<div><div>Inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and ion chromatography (IC) paired with either a conductivity detector (IC-CD) or single quadrupole mass spectrometer (IC-MS) are essential techniques in environmental analysis. Previous research has demonstrated robust agreement when applying these methods to Antarctic ice cores and snow samples. However, the high concentrations of sea spray and mineral dust found in Arctic snow samples pose distinct challenges, that might impact the accuracy and precision of measurements, despite the existing efforts to minimise matrix effects. In particular, the higher amount of dust in the Arctic snow/ice samples could present an additional source for insoluble elements typically found in sea spray that is insoluble and thus undetectable by IC, causing a divergency between the results obtained from the two techniques. Therefore, it is crucial to comprehend how these factors influence the efficacy of ICP-QMS and IC techniques in polar research. This study provides a detailed comparison of these methods in quantifying sea salt species – sodium (Na), potassium (K), magnesium (Mg), and bromine (Br) – in surface snow samples collected at Svalbard. By cross-validating IC and ICP-QMS for these tracers, the study assesses each method's accuracy, sensitivity, and precision, providing valuable insights into their optimal application in polar research and climate studies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106492"},"PeriodicalIF":3.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548573","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":"Effect of sediment composition and accumulation on pharmaceutical product spatial distributions at the suburban pond scale (Beulie pond, SNO Observil, France)","authors":"Amélie Humbrecht ,&nbsp;Anaëlle Simonneau ,&nbsp;Thomas Thiebault ,&nbsp;Gauthier Bernier-Turpin ,&nbsp;Claude Le Milbeau ,&nbsp;Veronika Veselská ,&nbsp;Josef Kašlík ,&nbsp;Gildas Ratié ,&nbsp;Lauriane Ledieu ,&nbsp;Lydie Le Forestier","doi":"10.1016/j.apgeochem.2025.106487","DOIUrl":"10.1016/j.apgeochem.2025.106487","url":null,"abstract":"<div><div>Pharmaceutical products (PPs) are found in several compartments of the environment, and are mostly emitted by wastewater treatment plants effluents. Their occurrence in the particulate phase, in opposition with the dissolved one, also promotes their occurrence in retention areas, where particles transported by streams settle. The study focuses on understanding how different constituents of pond sediment are distributed within a suburban pond, revealing patterns or hotspots of PPs accumulation. Results confirmed the heterogeneous spatial distributions of the granulometric fractions, total organic carbon, quantitative palynofacies, crystalline phase distributions and PPs contents. The delta preferentially concentrates total organic carbon (14.5 ± 2.2 %), and particularly terrigenous organic matter and neutral PPs, while the main decantation area accumulates mostly fine particles (58.2 ± 7.7 %), kaolinite, algal organic matter and cationic PPs. The potential role played by OM and kaolinite in PPs adsorption is supported by their respective spatial trends at the pond scale. Further attention should be paid to surface sediments components and PPs sensitivity to seasonal variations, especially in terms of flow, pH and oxygenation of the water-column. This spatial approach allowed to identify preferential accumulation and concentration areas within the pond, where the following extensive characterization of interface sediments highlighted the factor likely to influence PPs trapping within the pond.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106487"},"PeriodicalIF":3.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564103","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":"Sediment color as a predictor of the subsurface redox conditions at large scale","authors":"Hyojin Kim ,&nbsp;Ingelise Møller ,&nbsp;Lærke Thorling ,&nbsp;Birgitte Hansen","doi":"10.1016/j.apgeochem.2025.106493","DOIUrl":"10.1016/j.apgeochem.2025.106493","url":null,"abstract":"<div><div>The redox conditions of the subsurface are critical for predicting nitrate transport and fate in groundwater. Groundwater chemistry of redox-sensitive parameters can be used to infer subsurface redox conditions; however, it typically provides only point-scale information and requires significant time and effort to acquire large datasets. In soil science, soil/sediment colors have been used to qualitatively infer redox status in different soil horizons. In this study, we quantitatively assessed the potential of sediment color as a proxy for subsurface redox conditions at a national scale in Denmark. We did so by comparing sediment color classifications with groundwater redox conditions from approximately 4000 groundwater screens across the country. The sediment color dataset included seven base colors i.e., red, yellow, black, blue, green (olive), gray, and brown, encompassing a total of 89 variations, accounting for nuances (e.g., yellowish, grayish) and lightness (light vs dark). Our results revealed that, overall, qualitative redox interpretations based on sediment color aligned well with the oxic groundwater fraction. Gray and brown groups were the predominant colors, and within each group, the oxic water fraction increased with oxic-associated nuances (e.g., yellowish gray) and lighter shades (e.g., light yellowish gray) compared to their respective base color (i.e., gray). Most brown colors and gray shades with oxic (e.g., yellowish gray) and brownish nuances (e.g., brownish gray) showed oxic water fractions that decreased exponentially with increasing depth, suggesting hydrological controls on the redox conditions. Based on these findings, sediment color data from more than 27,000 boreholes across the country were quantitatively translated into oxic probability, enabling more precise delineation of the redox interface. Since sediment color data can be collected rapidly and at large scales, it provides a reliable and cost-effective means of assessing subsurface redox conditions. Therefore, sediment colors data have great potential to enhance large-scale modelling of redox-sensitive contaminant transport and fate.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106493"},"PeriodicalIF":3.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571850","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":"Coupling of Fe and N cycles by nitrate-reducing Fe(II)-oxidizing microorganisms in the tidal sediments of an extreme acidic river (Río Tinto, Spain)","authors":"Martina Bottaro ,&nbsp;Sergey Abramov ,&nbsp;Ricardo Amils ,&nbsp;Adrian Martinez-Bonilla ,&nbsp;Laurel ThomasArrigo ,&nbsp;Daniel Straub ,&nbsp;Muammar Mansor ,&nbsp;Sara Kleindienst ,&nbsp;Andreas Kappler","doi":"10.1016/j.apgeochem.2025.106488","DOIUrl":"10.1016/j.apgeochem.2025.106488","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Río Tinto (Huelva, Spain) is an acid rock drainage-affected fluvial estuarine system where Fe(II)-oxidizing microorganisms were shown to be active both in the water column and in the top sediment layer, contributing to Fe mineral accumulation (up to 30 % of dry sediment weight) in the estuarian sediment. However, it is still unknown if the Fe(II)-oxidizing microorganisms thriving in the upper sediment layer are also capable of using nitrate present in the river (0.05–0.5 mM) as electron acceptor. We performed sediment incubations amended with either lactate, acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; or NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; to evaluate Fe-cycling processes and, specifically, if nitrate reduction coupled to Fe(II) oxidation (NRFeOx) can occur in the sediment under anoxic conditions. Geochemical data showed that in the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt; (from 1.5 to 0 mM), Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; (from 1.5 to 0 mM) and pH (from 6.0 to 5.4) decreased, while the poorly crystalline Fe(III) mineral pool increased by 6.9 % during 114 days of incubation. In the acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup, nitrate reduction rates (0.31 mM NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/day) were 10 times faster compared to the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup (0.03 mM NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/day). pH and poorly crystalline Fe(II) mineral content increased due to Fe(III) reduction after amendment with only lactate (0.26 ± 0.03 mM Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;/day) but also after amendment with acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; (0.16 ± 0.02 mM Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;/day) suggesting that acetate-stimulated Fe(III) reduction superimposed Fe(II) oxidation coupled to nitrate reduction. Sequencing data showed that upon addition of nitrate, members of the genus &lt;em&gt;Rhodanobacter&lt;/em&gt; increased by ⁓10 % in relative DNA-based 16S rRNA gene abundances in both acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;- and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setups. However, the &lt;em&gt;Rhodanobacter&lt;/em&gt; RNA-based 16S rRNA relative gene abundance was higher in the acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup (11.15 ± 2.24 %) than in the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended one (5.40 ± 0.31 %). Combining geochemical and sequencing data obtained from anoxic sediment incubations, we conclude that NRFeOx processes, potentially catalyzed by the genus &lt;em&gt;Rhodanobacter&lt;/em&gt;, can play a role in Fe cycling in this extreme acid rock drainage affected river, under low organic carbon (OC) conditions. At higher OC levels, NRFeOx microorganisms seem to become more active but their net effects on Fe(II) oxidation can be diminished due to the simultaneous activi","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106488"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580584","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":"Probabilistic human health risk assessment due to potential toxic elements in gold mining-affected areas of Antioquia, Colombia","authors":"Julián E. López ,&nbsp;Samantha Jiménes-Oyola ,&nbsp;Juan F. Marín ,&nbsp;Juan F. Saldarriaga","doi":"10.1016/j.apgeochem.2025.106491","DOIUrl":"10.1016/j.apgeochem.2025.106491","url":null,"abstract":"<div><div>The purpose of this study was to determine the probabilistic human health risk (both non-carcinogenic and carcinogenic) associated with the concentration of potentially toxic elements (PTEs) in soil samples from gold mining-impacted areas in three municipalities of Antioquia, Colombia. Soil samples were collected from the study area, and the concentrations of As, Cd, Pb, and Cr were analyzed. Human exposure to these PTEs was assessed for both adults and children through incidental soil ingestion and dermal contact during outdoor activities. To evaluate the potential adverse health effects, PTEs concentrations were analyzed using the Hazard Index (HI) and Total Cancer Risk (TCR). The minimum and maximum concentrations of As, Cd, Pb, and Cr were 1.7–892 mg kg⁻¹, 0.1–65.2 mg kg⁻¹, 13.0–2345 mg kg⁻¹, and 5.4–301 mg kg⁻¹, respectively. The probabilistic risk analysis indicated HQ and CR values above the safe exposure threshold, suggesting that, if exposure conditions are maintained, residents exposed to contaminated soils may face risks to their health. The results indicate that in Puerto Berrío and Buriticá, a significant proportion of children are exposed to non-carcinogenic risk levels far exceeding safe limits, with Puerto Berrío being the most critical area, where exposure levels surpass the safety threshold by up to 40 times. Overall, the findings of this study provide new scientific evidence that can support data-driven decision-making for the development of regulations and improved environmental management strategies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106491"},"PeriodicalIF":3.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588340","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":"Electrochemical migration-induced mineral reactions at the bentonite-concrete interface in multi-barrier systems","authors":"Ajeong Kim ,&nbsp;Dongwoo Lee ,&nbsp;Jang-Soon Kwon ,&nbsp;Heewon Jung","doi":"10.1016/j.apgeochem.2025.106489","DOIUrl":"10.1016/j.apgeochem.2025.106489","url":null,"abstract":"<div><div>This study investigates the effect of electrochemical migration on the geochemical stability of multi-barrier nuclear waste repositories. We used a multicomponent reactive transport modeling approach to conduct two simulations: one considering only Fickian diffusion (FD) and another incorporating both Fickian diffusion and electrochemical migration using the Nernst-Planck equation (NP). The model domain consisted of bentonite, concrete, and granite barriers. The NP simulation results revealed Ca²⁺ fluxes moving against their concentration gradients across the bentonite-concrete interface (BCI), driven by Coulombic interactions. This uphill diffusion of Ca²⁺ is coupled with the downhill diffusion of SO₄²⁻, resulting in the concurrent migration of both ions from bentonite to concrete. This process triggers slow gypsum dissolution and precipitation near the BCI, even though local equilibrium with respect to gypsum was reached. These unexpected mineral reactions across the BCI persist even after gypsum is completely depleted in the bentonite near the interfaces, as long as the pore connection near the BCI is maintained. Our findings highlight the significance of electrochemical effects for the long-term stability of multi-barrier systems in nuclear waste repositories.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106489"},"PeriodicalIF":3.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548572","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":"Iodine incorporation into calcium phosphate minerals at hydrothermal conditions","authors":"Ángel Jiménez-Arroyo ,&nbsp;Rinat I. Gabitov ,&nbsp;Artas Migdisov ,&nbsp;Alberto Pérez-Huerta ,&nbsp;Juejing Liu ,&nbsp;Xiaofeng Guo ,&nbsp;Hongwu Xu ,&nbsp;Padmanava Dash ,&nbsp;Hakim Boukhalfa","doi":"10.1016/j.apgeochem.2025.106486","DOIUrl":"10.1016/j.apgeochem.2025.106486","url":null,"abstract":"<div><div>Among the numerous radionuclides generated by nuclear fission, radioiodine (¹²⁹I) poses a long-term environmental and health threat due to its high mobility, solubility, radiotoxicity, and 15.7 Ma half-life. Even though relatively small amounts of radioiodine are generated per ton of spent fuel, its accumulation has exponentially increased since the inception of the nuclear age. Many approaches for the immobilization of radioiodine have been extensively investigated. These methods, however, are still limited by thermodynamic instability, high costs, slow kinetics, and volatile loss during vitrification. Given the relationship and similarities of iodine species with other anions present in apatite, such a mineral still represents a promising host for the safe disposal of radioiodine. However, the interaction between aqueous iodine species and the mineral apatite at hydrothermal conditions remains a knowledge gap. This work evaluated the immobilization of iodate (IO₃⁻) and iodide (I⁻) from solutions by calcium phosphate minerals (apatite and monetite) at 39 and 200 °C. The performed analysis of our experimental solids encompassed electron microprobe analysis (EMPA), scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS), X-ray diffraction (XRD), and synchrotron X-ray absorption spectroscopy (XAS). In addition, the experimental solutions were analyzed using UV–visible spectrophotometry (UV–Vis) before and after the experiments to track redox changes if any, of the iodine species initially used and to derive iodine concentrations. Iodine concentrations acquired from EMPA (for solids) and UV–Vis (for solutions) were used to calculate the apparent Nernst partition coefficient of iodine as <span><math><mrow><msup><mi>D</mi><mi>I</mi></msup><mo>=</mo><mfrac><msub><mi>I</mi><mrow><mspace></mspace><mrow><mo>(</mo><mrow><mi>a</mi><mi>p</mi><mi>a</mi><mi>t</mi><mi>i</mi><mi>t</mi><mi>e</mi></mrow><mo>)</mo></mrow></mrow></msub><msub><mi>I</mi><mrow><mo>(</mo><mrow><mi>f</mi><mi>l</mi><mi>u</mi><mi>i</mi><mi>d</mi></mrow><mo>)</mo></mrow></msub></mfrac></mrow></math></span>. The highest iodine concentration found in apatite was 6.0 wt% when an iodate-bearing NaCl solution was used as the crystal growth medium. In experiments where iodide-bearing solutions were used, iodine concentrations in apatite ranged from 0.04 to 0.45 wt%. Partitioning data show that IO₃⁻ is more compatible with apatite (D &gt; 1) while I⁻ is less compatible (D &lt; 1). The results indicate that iodine incorporation into apatite is favorable at oxidizing conditions.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106486"},"PeriodicalIF":3.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502781","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":"Molecular markers of carbazole compounds in crude oils from NW China: Implications for organic facies and depositional paleoenvironment","authors":"Chuanyuan Wang ,&nbsp;Wentong Wang ,&nbsp;Zhaoquan Bao ,&nbsp;Zhongping Li ,&nbsp;Panjun Han","doi":"10.1016/j.apgeochem.2025.106484","DOIUrl":"10.1016/j.apgeochem.2025.106484","url":null,"abstract":"<div><div>The Tarim, Qaidam, and Ordos basins, located in Northwest China, are recognized as three significant oil and gas reservoirs, and a comprehensive geochemical analysis of the crude oils sourced from these basins has been conducted to elucidate the various factors, that influence the concentrations and distribution patterns of carbazole compounds. The average concentration of carbazole compounds in fresh lacustrine facies crude oil is significantly higher compared to those from salt lake facies and marine facies. Furthermore, salinity exerts a significant influence on the alkylation of methylcarbazole, whereas its effect on dimethylcarbazole alkylation is comparatively less pronounced. Under the premise of fully correcting the migration distance, the sedimentary environment (salinity, redox conditions) plays a dominant role in the distribution of carbazole compounds. Sedimentary facies and depositional environments also affect the total nitrogen concentrations and maturity-related parameters, such as the 1-MC/4-MC ratio. However, these factors minimal influence on migration indicators, such as the ratios of 3-MC/4-MC, 1,8-DMC/2,7-DMC, 1,3-DMC/2,7-DMC, and [a]/([a] + [c])-BC, which serve as reliable diagnostic tools for inferring the sedimentary environment. These findings indicate that carbazole compounds can serve as valuable tools for oil-source correlation studies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106484"},"PeriodicalIF":3.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511112","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":"Comparing greenhouse gas stable isotopes from different sampling methods: Aquifer groundwater and coal seam gas production waters","authors":"Julie K. Pearce ,&nbsp;Kim Baublys ,&nbsp;Harald Hofmann","doi":"10.1016/j.apgeochem.2025.106482","DOIUrl":"10.1016/j.apgeochem.2025.106482","url":null,"abstract":"<div><div>Methane and carbon dioxide are ubiquitous in aquifers and are gaining increased attention through their role in global warming. The stable carbon and hydrogen isotopes of methane and carbon dioxide, δ¹³C–CH₄, δ¹³C–CO₂ and δ²H–CH₄, can inform on the sources of gas in groundwater and determine if the origin is via thermogenic or different biogenic (microbial) processes. This can, for example, inform if there is connectivity between gas reservoirs and overlying aquifers. These stable isotopes are also used in monitoring in a range of settings, for example, during CO₂ geological storage. The pumping of groundwater to the surface results in depressurisation and gas effervescence, therefore the sampling method (i.e. if the sample contacts atmosphere) is known to affect measured dissolved gas concentrations; however, the effect of sample collection on the stable isotopes remains unresolved. Gas stable isotopes can be collected in the field in a range of sample containers, including dissolved gases in exetainer vials or Isoflasks; or free gases in gas bags or cylinders. Aquifer groundwaters, coal seam gas (CSG) production waters, and CSG free gases were collected from a range of bores for δ¹³C–CH₄, δ¹³C–CO_2, and δ²H–CH₄ analysis. Sample pairs of dissolved gases from exetainer vials and Isoflasks were mainly compared and generally had excellent low directional percentage variabilities. A subset of sample pairs from other containers (including free gas in gas cylinders or gas bags) were also compared with consistent stable isotope signatures generally measured. This brings confidence for using different sample containers if needed for different field conditions and situations.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106482"},"PeriodicalIF":3.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502780","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}