Applied Geochemistry最新文献

{"title":"Assessment for co-production of critical metals (lithium, copper, strontium) and geothermal heat in various geological formations of the North German basin","authors":"Simona Regenspurg ,&nbsp;Anika Thomas ,&nbsp;Nina Pogarell ,&nbsp;Jessica A. Stammeier ,&nbsp;Franziska D.H. Wilke ,&nbsp;Valby van Schijndel","doi":"10.1016/j.apgeochem.2026.106725","DOIUrl":"10.1016/j.apgeochem.2026.106725","url":null,"abstract":"<div><div>Several sedimentary formations and lithologies such as limestone from the Muschelkalk or sandstone from the Bunter or from the Rotliegend are considered for geothermal exploitation in the North German Basin. The production and analysis of geothermal fluids from deep wells in this area already showed an increased content of certain critical raw materials (CRM) in some brines indicating that a co-production of geothermal heat and CRM could be economically interesting. In this study, the overall potential of 23 geological formations for CRM co-production of the 4 km deep geothermal well from the Groβ Schönebeck site was assessed with focus on the CRM elements lithium (Li), copper (Cu), and strontium (Sr). For this, the total elemental content of 23 rocks samples from different depths between 1.4 and 4.1 km was determined. Highest Sr was identified in the limestones of Muschelkalk (2330 mg/kg) and Werra formation (2980 mg/kg). Copper was mainly enriched in the Kupferschiefer (214 mg/kg) and the Upper Rotliegend sandstones (79 mg/kg), and Li mainly in the Rotliegend conglomerates (up to 200 mg/kg).</div><div>To determine how strong and to which minerals these CRM are bound within the rocks, leaching and sequential extraction experiments were performed on five selected formation rock samples that are considered either for geothermal exploitation (Muschelkalk, Buntsandstein, Rotliegend sandstone) and/or as potential source for the CRMs Li, Cu, Sr (Permo-Carboniferous volcanic rocks, Ohre anhydrite). These experiments revealed that Sr was predominantly bound to carbonates indicating incorporation in calcite minerals. For Cu no clear source rock was identified although a volcanic origin seems most likely. Lithium was strongly bound to all investigated rocks (&lt;5 % of total Li was extractable) indicating a binding to the silicate phases.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106725"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424688","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":"Geochemical controls on silicification and biofilm stabilization in an intertidal hydrothermal spring: evidence from Puertecitos, Baja California","authors":"Yorfrank Arellano-Ramírez ,&nbsp;Enrique Iñiguez ,&nbsp;Rufina Hernández-Martínez ,&nbsp;Juan I. Sánchez-Ávila ,&nbsp;Thomas G. Kretzschmar","doi":"10.1016/j.apgeochem.2026.106736","DOIUrl":"10.1016/j.apgeochem.2026.106736","url":null,"abstract":"<div><div>Intertidal hydrothermal systems provide natural laboratories for investigating near-surface geochemical and microbial interactions. Here, we integrate field measurements (temperature, pH, and electrical conductivity), PHREEQC-based saturation index (SI) modeling, and SEM/EDS analyses to quantify how temperature, redox (pe), and seawater mixing regulate mineral precipitation and microbial preservation in the intertidal hydrothermal spring at Puertecitos, Baja California. Major-ion chemistry was measured for the two endmembers (YAPU01, YAPU16). The intermediate stations are described using in situ T–pH–EC as mixing proxies. Modeling of vent-proximal water (YAPU01; 73 °C, pe ≈ 0 and pe = 8.41) and marine-influenced rim water (YAPU16; 32.7 °C, pe = 8.41) shows persistent silica supersaturation across the natural temperature window, which strengthens upon cooling. Oxidation stabilizes Fe-oxyhydroxides at lower temperatures, whereas carbonates and gypsum reach supersaturation primarily within the cooler, marine-influenced apron. SEM/EDS observations reveal 1) abundant filamentous and bacillary morphotypes at ∼60 °C that decline to near zero by ∼46-50 °C, 2) biofilm dominance at ≤41-33 °C, and 3) silica matrices with carbon co-localized to rods and bacilli, consistent with microbial templating and progressive silicification. In contrast, Ba-free, C/N poor elongated fabrics are interpreted as nondiagnostic sinter textures. Together, these results define a process framework in which abiotic silica precipitation is pervasive but microbially templated, and additional Fe-oxide-gypsum-carbonate pathways emerge with cooling and redox evolution. This integrated geochemical-textural approach clarifies shoreline diagenesis, biosignature preservation potential, and trace element scavenging at the hydrothermal-marine interface.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106736"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424684","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":"Pore-scale reactive transport for assessing permeability changes on CO2 capture and storage","authors":"Jeremy T. First ,&nbsp;Yuliana Zapata ,&nbsp;Srivatsa Mudumba Ramana ,&nbsp;Glen L. Gettemy ,&nbsp;Jonathan Hodgkinson","doi":"10.1016/j.apgeochem.2026.106728","DOIUrl":"10.1016/j.apgeochem.2026.106728","url":null,"abstract":"<div><div>Reactive transport modeling has increasingly become a key simulation capability in the risk management of subsurface operations, particularly when dealing with reactive fluids, such as monitoring of CO₂ plume migration in carbon capture and storage (CCS) operations. The pore-scale complexities and mineral distribution play a fundamental role in the dynamic porosity and permeability exhibited by a rock upon invasion of a reactive fluid. Here, we present an implementation of pore-scale reactive transport (PSRT) – using a generalized rate law that can be extended to any mineral – for simulating the evolving pore geometry of a digital rock due to dissolution and precipitation reactions within the rock. We validate our implementation against a well-known single-mineral benchmark simulation case and previously published microfluidics experiments, before applying the framework to a realistic CCS scenario with multiple minerals using a <span><math><mrow><mi>μ</mi><mi>CT</mi></mrow></math></span> image from an appraisal well in Texas. For our sandstone comprising calcite, quartz, clay, and feldspar, we show total dissolution of calcite and delayed, nominal dissolution of anorthite over a 2-hour time frame, resulting in a 41.1% relative increase in porosity and a 242% relative increase in permeability in the absence of grain compaction effects. We demonstrate the importance of 3D PSRT simulations for CCS scenarios by investigating the heterogeneity of mineral reaction rates. Our approach reveals relationships between porosity–permeability and porosity–tortuosity that would not be captured by lower-dimensional methods. We show that these relationships can be directly observed from PSRT simulations and interpreted via a streamline analysis of the evolving flow fields.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106728"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424687","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":"Groundwater helium isotope characteristics and source identification in Leizhou Peninsula, southern China","authors":"Shaoheng Li ,&nbsp;Zuobing Liang ,&nbsp;Werner Aeschbach ,&nbsp;Dioni I. Cendón ,&nbsp;Wen Wei ,&nbsp;Qirui Wu ,&nbsp;Di Tian ,&nbsp;Rouyan Gong ,&nbsp;Gang Zeng ,&nbsp;Zaizhi Yang ,&nbsp;Jianyao Chen ,&nbsp;Linyao Dong","doi":"10.1016/j.apgeochem.2026.106750","DOIUrl":"10.1016/j.apgeochem.2026.106750","url":null,"abstract":"<div><div>Helium isotopes, alongside radiocarbon (¹⁴C) dating and the elemental ratio ²⁰Ne/⁴He, were employed to investigate groundwater evolution in the Leizhou Peninsula, southern China. Groundwater samples were categorized into two groups based on corrected ¹⁴C age: Group Ⅰ (modern recharge, &gt;75pMC) and Group Ⅱ (older groundwater, 1-75 pMC) with ages ranging up to ∼29,000 years BP. Helium isotope analysis revealed distinct sources: Group Ⅰ exhibited elevated ³He/⁴He ratios (&gt;1 Ra) and tritiogenic ³He, reflecting atmospheric dominance, while Group Ⅱ showed lower ³He/⁴He ratios (&lt;1 Ra) and radiogenic ⁴He accumulation, consistent with prolonged groundwater residence time and water-rock interaction. A notable exception was a volcanic island sample with anomalously high ³He/⁴He (∼3 Ra) and helium concentrations, indicating a localized mantle-derived helium contribution. A ternary mixing model quantified helium sources, demonstrating increasing crustal contributions (1-52%) with groundwater age. Moreover, dissolved ⁴He concentrations show a positive correlation with corrected ¹⁴C ages, yielding a radiogenic ⁴He accumulation rate of 2.76 × 10⁻⁹ ccSTP/g/ka, supporting ⁴He as a complementary groundwater chronometer. These findings emphasize time-dependent noble gas accumulation and mixing processes within the aquifer system, offering insights for sustainable groundwater management in the study area.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106750"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424691","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":"Factors affecting surface precipitate solubility products of nickel at the montmorillonite-water interface","authors":"Chaoran Huo,&nbsp;Yang Wu,&nbsp;Chiyu Zhang,&nbsp;Yibing Ma","doi":"10.1016/j.apgeochem.2026.106751","DOIUrl":"10.1016/j.apgeochem.2026.106751","url":null,"abstract":"<div><div>Surface precipitates of metals at soil-water interfaces were identified. Recently, the surface precipitate apparent solubility product (<em>K</em>_<em>sp</em><em>’</em>) of nickel (Ni) at the montmorillonite-water interface was first determined using the Langmuir-precipitation model, enabling quantitative prediction of Ni partitioning. Factors affecting interface surface precipitation are critical for thermodynamic and mechanistic understanding but remain unstudied. In the present study, the nickel hydroxide's <em>K</em>_<em>sp</em><em>’</em> at the montmorillonite-water interface under varying pH, temperature (T), and montmorillonite concentrations were investigated. It was found that <em>K</em>_<em>sp</em><em>’</em> decreased significantly with increases in the pH and montmorillonite concentration: p<em>K</em>_<em>sp</em><em>’</em> increased by 0.03 per 0.1 pH increase and by 0.04 per 1 g L⁻¹ montmorillonite concentration increase. The values of <em>K</em>_<em>sp</em><em>’</em> ranged from 2.19 × 10⁻¹⁷ to 5.25 × 10⁻¹⁷, which were 39 to 91 times lower than the solubility product (<em>K</em>_<em>sp</em>, 2.00 × 10⁻¹⁵) of Ni(OH)₂ in a pure water system. Thermodynamic parameters (enthalpy change, <em>ΔH</em>^<em>0</em> = 36.62 kJ mol⁻¹; entropy change, <em>ΔS</em>^<em>0</em> = 0.438 kJ/(mol·K); Gibbs free energy change, <em>ΔG</em>^<em>0</em> &lt; 0) indicate that surface precipitation is an endothermic reaction overall with an increase in entropy, contrary to precipitation in pure water, and is spontaneous (T &gt; 84K). These findings can effectively predict Ni retention at soil-water interfaces, addressing critical gaps in conventional environmental risk assessments of surface precipitation mechanisms.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106751"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147425011","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":"Temperature-constrained sorption of inorganic and organic selenium by Fe-oxide minerals: Significance for selenium bioavailability in Earth's critical zone","authors":"Kunfu Pi ,&nbsp;Qianyong Liang ,&nbsp;Yiqun Gan ,&nbsp;Yaping Zhang ,&nbsp;Tao Gu ,&nbsp;Li Zhang","doi":"10.1016/j.apgeochem.2026.106733","DOIUrl":"10.1016/j.apgeochem.2026.106733","url":null,"abstract":"<div><div>Temperature influences hydrobiogeochemical processes and consequent fate of selenium (Se) in the Earth's critical zone. Quantitative understanding of the temperature-constrained sorption behaviors of both inorganic and organic Se species, however, is critically lacking. Using ferrihydrite and goethite as comparative sorbents in batch experiments under wide ranges of environmental temperature (5-40 °C) and pH (5-9), we mechanistically identify the effects of temperature on sorption kinetics and thermodynamics of four key Se species: selenate (Se(VI)) and selenite (Se(IV)) as inorganic Se oxyanions, as opposed to DL-selenocystine (SeCys) and DL-selenomethionine (SeMet) as organic Se zwitterions. Although sorption of the four Se species occurred more rapidly on ferrihydrite than on goethite, increasing temperature overall reduced Se retention by Fe-oxide minerals. Despite the overall rapid sorption observed for all Se species, model-derived rate constants demonstrate higher sorption rates for ferrihydrite than goethite, and this kinetic contrast is amplified as temperature increases. Temperature-dependent kinetic fitting indicates that sorption of Se(IV), Se(VI), and SeCys is more consistent with surface reaction-controlled (activation-controlled) complexation than SeMet, which shows weaker temperature sensitivity agreeing with less specific interaction. Thermodynamic parameters derived from the revised Langmuir isotherms indicate exothermic Se sorption on Fe oxides and affinity shift with temperature, pH, and Se speciation. A diffuse-layer surface complexation model captures the observed temperature and pH dependence by accounting for coupled changes in aqueous Se speciation, surface protonation (thus effective site availability), and surface complexation thermodynamic constants. Therefore, temperature as a key driver of Se sorption plays a nonnegligible role in controlling Se mobility and potential bioavailability in the critical zone.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106733"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424690","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":"Hydrogeochemical processes driving elevated Arsenic and Fluoride in the Texas Gulf Coast Aquifer","authors":"Hailey N. Goodwin ,&nbsp;Taehyun Roh ,&nbsp;Reid Buskirk ,&nbsp;D. Kirk Nordstrom ,&nbsp;Franco Marcantonio ,&nbsp;Peter S.K. Knappett","doi":"10.1016/j.apgeochem.2026.106713","DOIUrl":"10.1016/j.apgeochem.2026.106713","url":null,"abstract":"<div><div>Dissolved arsenic (As) and fluoride (F) concentrations frequently exceed the United States Environmental Protection Agency (US EPA) drinking water standards in groundwater wells screened within the three aquifers (Chicot, Evangeline, Jasper) that comprise the Gulf Coast Aquifer (GCA) in Texas. The primary objective of this study is to identify the hydrological and geochemical processes that mobilize dissolved groundwater As and F in each aquifer across a north-south climate gradient from humid to semi-arid. Comprehensive chemistry was analyzed from 1164 water samples taken from 534 wells between 2002 and 2022 and reported in a public database of the Texas Water Development Board (TWDB). Surface and geologic sources of As and F were tested by observing their spatial correlation to land use and geologic layers. Multivariate analysis revealed that in the Northern and Central climate zones As covaries with dissolved iron (Fe) and/or manganese (Mn), whereas F varies with bicarbonate (HCO₃), sodium (Na), and pH. In the Southern climate zone As and F covary with vanadium (V). Plausible chemical reactions that generated As and F were analyzed with geochemical plots and stoichiometric inverse modeling. The dissolved products of silicate hydrolysis and cation exchange were evident along all flowpaths. The removal of Ca from solution through cation exchange drives calcite and fluorite dissolution, which is inferred to be the primary source of F to groundwater in the Northern and Central climate regions, whereas the reductive dissolution Fe- and Mn-oxides releases dissolved As. Arsenic and F are released to Southern aquifers primarily by silicate weathering of the Catahoula Formation volcanic ash layers. This study reveals the changing drivers of As and F release across a 650 km wide region with varying geology and climate. Understanding these drivers is important for deciding the best strategy for avoiding consumption of the polluted groundwater or making the contamination worse through land use or groundwater pumping.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106713"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147425008","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":"Applied Geochemistry Recognizes Excellence in Peer Review: 2025 Awards","authors":"Zimeng Wang ,&nbsp;Elisa Sacchi ,&nbsp;Philippe Van Cappellen ,&nbsp;Yanxin Wang","doi":"10.1016/j.apgeochem.2026.106735","DOIUrl":"10.1016/j.apgeochem.2026.106735","url":null,"abstract":"","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106735"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147449677","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":"Boron and oxygen isotopes fractionation between borate minerals and fluids and implications for borate deposit formation","authors":"Da-Sheng Zuo ,&nbsp;Hai-Zhen Wei ,&nbsp;Jian-Jun Lu ,&nbsp;M.R. Palmer ,&nbsp;A.E. Williams-Jones ,&nbsp;Jun-Lin Wang ,&nbsp;Shao-Yong Jiang ,&nbsp;Ke Yang ,&nbsp;He-Feng Lin ,&nbsp;Simon V. Hohl ,&nbsp;Yi-Chu Chen","doi":"10.1016/j.apgeochem.2026.106732","DOIUrl":"10.1016/j.apgeochem.2026.106732","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Boron and oxygen isotope studies have the potential to reveal important information regarding the formation of the borate minerals that form in non-marine evaporite deposits and are the major economic source of boron. In particular, boron isotopes can provide information concerning the source of boron and the pH conditions during borate precipitation, and oxygen isotopes can be used to constrain crystallization temperatures and the extent of evaporation of the brines. However, quantitative application of boron and oxygen isotope studies of borate minerals are hindered by the lack of isotope fractionation factors for both isotopes. Experimental determination of these values is difficult because of the problem of achieving equilibrium conditions at low temperatures. Hence, this work systematically calculates the reduced partition function ratios (RPFRs, β values) of boron and oxygen isotopes in borate minerals and brine using density functional theory. The results indicate that the 10&lt;sup&gt;3&lt;/sup&gt;lnβ among these minerals decreases in the sequence of borax ≈ kernite &gt; ulexite ≈ probertite &gt; teruggite &gt; hydroboracite &gt; kurnakovite &gt; colemanite &gt; priceite &gt; pinnoite &gt; howlite for boron isotopes and in the order of howlite &gt; hydroboracite priceite &gt; colemanite &gt; kernite &gt; probertite &gt; pinnoite &gt; ulexite &gt; teruggite &gt; kurnakovite &gt; borax for oxygen isotopes. These 10&lt;sup&gt;3&lt;/sup&gt;lnβ values for boron isotopes are primarily influenced by the BO&lt;sub&gt;3&lt;/sub&gt;/BO&lt;sub&gt;4&lt;/sub&gt; ratio in borate minerals while the chemical composition (cationic type) has a subordinate effect. Thus, the temperature dependence of boron isotope fractionation between borate minerals and fluids at pH of 8.60 has been derived as following: Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;borax-fluid&lt;/sub&gt; = - 0.0016 T&lt;sup&gt;2&lt;/sup&gt; + 0.1375T - 4.2902, Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;colemanite-fluid&lt;/sub&gt; = - 0.0016 T&lt;sup&gt;2&lt;/sup&gt; + 0.1525T - 8.5653 and Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;ulexite-fluid&lt;/sub&gt; = - 0.0017 T&lt;sup&gt;2&lt;/sup&gt; + 0.1724T - 13.7696. The impact of fluid pH on boron isotope fractionation is also significant, where the pH dependent boron isotope fractionation at 298.15 K can be quantified as: Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;borax-fluid&lt;/sub&gt; = &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mn&gt;8.597&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mn&gt;8.597&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mn&gt;25.8853&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;11.1907&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;colemanite-fluid&lt;/sub&gt; = &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mn&gt;8.597&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mn&gt;8.597&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mn&gt;25.8853&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2.526&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Δ&lt;sup&gt;11&lt;/sup&gt;B&lt;sub&gt;ulexite-fluid&lt;/sub&gt; = &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mn&gt;8.597&lt;/mn","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106732"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147424686","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":"Sources and mobilisation pathways for geogenic arsenic contamination in groundwaters; a case study from eastern Ireland","authors":"Alexander Russell ,&nbsp;David van Acken ,&nbsp;Frank McDermott","doi":"10.1016/j.apgeochem.2026.106747","DOIUrl":"10.1016/j.apgeochem.2026.106747","url":null,"abstract":"<div><div>Reconnaissance sampling of domestic water supplies in the Brittas area of Co. Dublin, Ireland detected arsenic concentrations up to 69 μg/L, with 55% of samples exceeding the World Health Organisation (WHO) limit of 10 μg/L, indicating a potential health risk to the local population. Follow-up sampling using low-flow techniques confirmed arsenic concentrations up to 54 μg/L and 52 μg/L in unfiltered and filtered water samples, with median values of 24.8 μg/L and 24 μg/L respectively and &gt;70% of samples exceeding the WHO drinking water limit for arsenic. Waters from small surface streams in the area also exhibit high arsenic concentrations (up to 85 μg/L) with a median value of 54.3 μg/L. Elevated arsenic in the surface- and ground-waters reflect regional-scale elevated arsenic in arsenopyrite-bearing Lower Palaeozoic greywacke-slate bedrocks, that also produced stream-sediment arsenic anomalies up to 217 mg/kg. SEM-EDX investigations of the greywackes identified arsenopyrite in quartz veins that occur within bedrock fractures as the primary mineralogical source of arsenic. Groundwaters with low pH, low alkalinity, low electrical conductivity, and relatively high Eh values are associated with the highest arsenic. Deeper wells show elevated dissolved arsenic, but multiple mobilisation and remobilisation steps are required to explain the hydrochemical data. Dissolved arsenic and sulphate are decoupled in the groundwaters by secondary barite precipitation. Separately, analyses of unfiltered tap waters, sampled to represent waters used by well owners, indicate mobilisation of adsorbed arsenic on entrained iron-manganese oxyhydroxides particulates by high-speed submersible in some wells.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"200 ","pages":"Article 106747"},"PeriodicalIF":3.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147425014","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}