Applied Geochemistry最新文献

{"title":"Modelling cadmium binding to plant-based biochars using the three-site NICA-Donnan model","authors":"Yifan Huang ,&nbsp;Gerwin F. Koopmans ,&nbsp;Zhengguo Song ,&nbsp;Rob N.J. Comans ,&nbsp;Liping Weng","doi":"10.1016/j.apgeochem.2025.106404","DOIUrl":"10.1016/j.apgeochem.2025.106404","url":null,"abstract":"<div><div>In this study, generic three-site NICA model parameters for cadmium (Cd) binding to biochars were derived. For this purpose, five biochars prepared from two mixtures of pure cellulose and lignin and maize straw at different pyrolysis temperatures were selected from our previous work to measure Cd binding in batch experiments. This dataset was complemented with data on Cd binding from five other plant-based biochars taken from literature. The three-site NICA model in combination with an electrostatic Donnan model using a constant Donnan volume <span><math><mrow><msub><mi>V</mi><mi>D</mi></msub></mrow></math></span> of 0.1 L kg⁻¹ successfully described the data, covering a wide range in pH and free Cd²⁺ concentration in solution. The model provided quantitative insights into the surface speciation of Cd and the electrostatic interactions between Cd and biochar. Carboxylic- and phenolic-type reactive groups exhibited a lower Cd affinity compared to protons, leading to a strong pH dependency of Cd binding. Cadmium ions bind predominantly as a monodentate complex with carboxylic groups and as mono- and bidentate complexes with phenolic groups on biochar. Although phenolic groups have a higher affinity to bind Cd, carboxylic groups dominate Cd binding due to the smaller difference in the affinity of the latter groups to bind Cd and protons. In addition, the small ionic strength effect on Cd adsorption can be ascribed to the low charge density of biochar and the presence of basic groups (i.e., the third type of sites) on biochar. The basic groups generate positive charge, neutralizing to a certain extent the negative charge generated by the acidic groups, thus weakening the ionic strength effect. Due to this electrostatic effect, ignoring the presence of the basic groups will lead to an overestimation of Cd binding by biochar. In addition to these quantitative mechanistic insights, the derived generic model parameters for the three-site NICA-Donnan model can help to predict Cd binding to unknown biochars over a wide range in pH and ionic strength to support the design of <em>in-situ</em> soil remediation operations.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"186 ","pages":"Article 106404"},"PeriodicalIF":3.1,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887097","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":"Bulk rock geochemical and mineralogical characterisation of clay-rich sediments from drill core analysis of the Staffelegg Formation","authors":"Marie Bonitz ,&nbsp;Theresa Hennig ,&nbsp;Anja M. Schleicher ,&nbsp;David Jaeggi ,&nbsp;Jessica A. Stammeier ,&nbsp;Christian Ostertag-Henning ,&nbsp;Michael Kühn","doi":"10.1016/j.apgeochem.2025.106389","DOIUrl":"10.1016/j.apgeochem.2025.106389","url":null,"abstract":"<div><div>The long-term integrity of argillaceous formations as host rocks for deep geological disposal of nuclear waste depends significantly on hydrogeological factors. A 58 m long borehole was drilled at the Mont Terri Rock Laboratory (Switzerland) from the Opalinus Clay through the entire underlying Staffelegg Formation, which includes two water-bearing sections. Groundwater was found locally in the Beggingen and Rietheim Members, otherwise known as Gryphaea Limestone and Posidonia Shale, respectively. We want to identify indicators to determine the impact of groundwater flow in clay- and carbonate-rich sediments by characterising mineralogical and geochemical alteration. The groundwater influence is restricted to the water-bearing zones and can be identified by fractures and calcite veins. Additional indicators like mineral assemblage, rock geochemistry and the combination of different redox proxies, show constrained groundwater influence in the clay-rich areas. To investigate in particular the water-bearing horizons on a smaller scale (mm-<span><math><mi>μ</mi></math></span>m) would help to detect further alteration and mobilisation features.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"186 ","pages":"Article 106389"},"PeriodicalIF":3.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877492","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":"Uranium(VI) retention by calcium (alumino)silicate hydrates – Impact of temperature and ionic strength","authors":"Katja Schmeide ,&nbsp;Nina M. Huittinen ,&nbsp;Salim Shams Aldin Azzam ,&nbsp;Frank Bok ,&nbsp;Erica Brendler ,&nbsp;Barbara Lothenbach ,&nbsp;Jerome Kretzschmar","doi":"10.1016/j.apgeochem.2025.106400","DOIUrl":"10.1016/j.apgeochem.2025.106400","url":null,"abstract":"<div><div>Calcium aluminosilicate hydrates (C-A-S-H) are the main hydration products of cement formulations with Al-rich additives such as blast furnace slags, fly ashes or calcined clays. We studied systematically the effect of Al substitution on both the structure of C-A-S-H phases and their U(VI) retention properties in comparison to C-S-H phases. To represent the different stages of cement degradation, three series of samples were synthesized, which included samples with Ca/Si molar ratios of 0.8, 1.2 and 1.6 and different Al/Si molar ratios of 0, 0.06 and 0.18 for each series. Furthermore, the impact of synthesis temperature (room temperature, 100 °C, 200 °C) on the C-(A-)S-H structure was studied. The U(VI) retention, studied either by sorption experiments or by direct synthesis of U(VI)-containing C-(A-)S-H phases, was found to be strong with log <em>R</em>_d between 4.9 and 5.6. Structural characteristics of the cementitious phases were obtained from powder X-ray diffraction (XRD) as well as ²⁹Si and ²⁷Al solid-state magic angle spinning nuclear magnetic resonance (SS MAS NMR) spectroscopy. AlO₄ tetrahedra were identified to occupy bridging positions of the silicate chains, thereby increasing the mean chain length and providing additional sorption sites for U(VI) at room temperature. Elevated temperatures during solid phase formation, however, lead to a stronger cross-linking of the silicate chains with the appearance of neoformed crystalline phases. Luminescence spectroscopy was applied to characterize the U(VI) binding. Various U(VI) species (interlayer or surface sorbed) are formed in different proportions, depending on the composition and structure of the C-(A-)S-H phases, which are partly affected by elevated temperatures. To simulate salinity changes of the pore water, the effect of enhanced ionic strengths and the presence of carbonate on the stability of the U(VI) retention by the C-(A-)S-H phases was studied by sorption and leaching experiments over extended timescales of up to 6 months. For C-(A-)S-H phases previously exposed to temperatures of up to 100 °C, the effect of medium ionic strengths (up to 2.6 M) on U(VI) retention was insignificant.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"186 ","pages":"Article 106400"},"PeriodicalIF":3.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898554","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":"Variability of fracture surface roughness in crystalline host rocks: implications for transport model simplifications","authors":"Wenyu Zhou ,&nbsp;Johannes Kulenkampff ,&nbsp;Daniel Jara Heredia ,&nbsp;Thorsten Schäfer ,&nbsp;Cornelius Fischer","doi":"10.1016/j.apgeochem.2025.106401","DOIUrl":"10.1016/j.apgeochem.2025.106401","url":null,"abstract":"<div><div>Variability in fracture geometry and its complex surface characteristics are major contributors to solute transport and retention effects in rocks such as granite. Understanding the effects of cross-scale fracture geometry on solute transport modeling is critical for reliable quantitative predictions in applications such as geothermal energy use and nuclear repository safety. Here, we systematically investigated the sensitivity of fracture surface topography variability to the flow field and solute transport behavior. Specifically, we investigated the role of multiscale fracture surface roughness in solute transport modeling. As a starting point, our study utilized a 3D fracture geometry derived from CT scans and employed COMSOL Multiphysics software for solute transport modeling. By introducing increasingly lower spatially resolved geometries, while maintaining a constant high resolution mesh for simulation calculations, we investigated the consequences for transport on surfaces composed of superimposed building blocks of different sizes and shapes. The results indicate that fracture geometry simplifications with reduced spatial frequency information of well-defined, specific domains do not have a clear trend to alter the BTCs tailing. Instead, this type of model simplification can cause both increased and decreased tracer residence times, leading to misleading interpretations. We explain this by a complex superposition of surface building blocks of different sizes, such as single crystal surface pits, grain boundaries between crystals, and fracture curvature. For model sensitivity analyses, we suggest the use of concentration difference and acceleration maps to identify local transport heterogeneities introduced by geometric simplifications. In addition, we conclude that power spectral density (PSD) analysis provides a means of defining a range of surface spatial frequencies that helps to avoid oversimplification in geometric models of reactive transport.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"186 ","pages":"Article 106401"},"PeriodicalIF":3.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870648","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":"Specific responses of minerals during the dissolution of basalt for geological storage of CO2","authors":"Jun-Hwan Bang,&nbsp;Taehee Kim,&nbsp;Soo-Chun Chae,&nbsp;Kyungsun Song","doi":"10.1016/j.apgeochem.2025.106402","DOIUrl":"10.1016/j.apgeochem.2025.106402","url":null,"abstract":"<div><div>Dissolution experiments involving basalt grains (grain size: 0.841–1.190 mm) were conducted under CO₂-saturated conditions to investigate mineralogical changes and fluid chemistry dynamics relevant to geological CO₂ storage. The experiments were initially performed at 35 °C (up to 137 days) and subsequently at 50 °C (up to 210 days). Mineralogical analyses were conducted using scanning electron microscopy with backscattered electron imaging (SEM-BSE), electron probe microanalysis (EPMA), and X-ray diffraction (XRD). The initial dissolution stage was characterized by rapid olivine dissolution, causing substantial early release of magnesium (Mg) and iron (Fe). Labradorite dissolution became increasingly significant after the temperature increase to 50 °C, enhancing mobilization of calcium (Ca), magnesium (Mg), and aluminum (Al). SEM-BSE analyses revealed distinctive dissolution textures on olivine grains, characterized by pronounced Mg depletion and Fe enrichment. Fluid chemistry results reflected these mineralogical changes, indicating rapid initial Mg release, sustained mobilization of silicon (Si) and Fe from ongoing olivine dissolution, and elevated Ca and Al concentrations after temperature elevation due to increased dissolution of plagioclase (labradorite) and, to a lesser extent, augite. Secondary silica precipitation occurred during later reaction stages, inferred from decreasing dissolved Si concentrations. These findings emphasize temperature- and mineral-specific dissolution behaviors, providing critical insights for optimizing basalt-hosted CO₂ sequestration.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"186 ","pages":"Article 106402"},"PeriodicalIF":3.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853878","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":"Amendment effectiveness and seasonal variations in a lead contaminated acidic wetland","authors":"Matthew R. Noerpel ,&nbsp;Anna M. Wade ,&nbsp;Aaron R. Betts ,&nbsp;Jennifer Goetz ,&nbsp;Robert Ford ,&nbsp;Amy Krause ,&nbsp;Michael Zeolla ,&nbsp;Diana Cutt ,&nbsp;Stephanie M. Wilson ,&nbsp;Todd P. Luxton","doi":"10.1016/j.apgeochem.2025.106396","DOIUrl":"10.1016/j.apgeochem.2025.106396","url":null,"abstract":"<div><div>Three in-situ lead (Pb) soil amendment treatment methods were tested over 26 months in a naturally acidic contaminated wetland with the intent of sequestering high levels of Pb contamination as stable mineral forms. Two of the treatments used Apatite II, a phosphate-based amendment, to promote the formation of pyromorphite. The apatite amendment was surface applied one method and physically mixed to the surface soils in the other. A sulfate-rich compost-based mixture was used for the third treatment, with the goal to promote the formation of galena. Amendment effectiveness was evaluated by comparison of Pb porewater concentrations between treatments, and by changes in the speciation of sediment Pb as determined by X-ray absorption spectroscopy (XAS). Results show that in the two years following application, the three treatments did not make a significant impact on Pb mobility and speciation. Dissolved Pb concentrations did not decrease significantly in the treatment plots in comparison to the control plots. Furthermore, speciation analysis did not show evidence of pyromorphite formation in the phosphate-amended plots. Galena was found in the third treatment with sulfate-rich compost, however the significance of this was limited by sample size and the presence of galena in other areas of the wetland. There was a seasonal variation in the Pb speciation, with galena and Pb-cysteine being more prevalent at the end of the wet season and less prevalent at the end of the dry season, indicating that while the induced formation of reduced Pb-sulfur species is possible, there are challenges to maintaining those species without concurrent control of soil water saturation. This study shows that effective amendment treatments must account for site-specific characteristics such as pH and redox dynamics, and use appropriate preservation methods for accurate speciation results.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"185 ","pages":"Article 106396"},"PeriodicalIF":3.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839031","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 and isotopic (oxygen, hydrogen, sulfur) indicators constraining the origin and contribution ratios of dissolved sulfate in shallow aquifers from the lower Yellow River floodplain, northern China","authors":"Han Geng ,&nbsp;Chunli Su ,&nbsp;Weijiang Liu ,&nbsp;Junxia Li ,&nbsp;Xianjun Xie ,&nbsp;Huijian Shi ,&nbsp;Zhantao Han","doi":"10.1016/j.apgeochem.2025.106388","DOIUrl":"10.1016/j.apgeochem.2025.106388","url":null,"abstract":"<div><div>Sulfate (SO₄²⁻) contamination of groundwater is becoming a major public health threat in the lower Yellow River floodplain of southwest Shandong Province. In this study, 72 shallow groundwater samples, 18 surface water samples and 21 industrial wastewater samples (including 4 mine drainage samples used to analyze the effects of coal mining activities) were collected to investigate the origins of sulfate in the water environment. Hydrochemical and isotopic data of SO₄²⁻ (δ³⁴S and δ¹⁸O) and H₂O (δD and δ¹⁸O) as well as stable isotope mixing models in R (SIMMR) were integrated to identify the sulfate sources and the proportions of each source in different watersheds. The results showed that chemical fertilizer is the dominant source of sulfate in surface water in most of the area, while manure and atmospheric deposition are the main sources of sulfate in groundwater. The contributions of evaporites dissolution to sulfate are most significant in surface water and groundwater in Jiaxiang and southern Yuncheng counties. In areas with intensive industrial activities, the contribution of industrial sewage to water bodies is also considerable. The groundwater in Juye and Jiaxiang Counties in the downstream of Zhuzhaoxin River is worst affected by mine drainage. The hydrogeological setting and anthropogenic activities jointly controlled the sulfate in the water. The research not only provide useful methodology and clues for similar studies in other sulfate contaminated areas, but also exemplify the vital importance of hydrogeochemical and isotopic monitoring for the sustainable management of water resources.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"185 ","pages":"Article 106388"},"PeriodicalIF":3.1,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828809","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":"Isotope geochemical study of the origin and formation mechanism of carbonate minerals in geothermal wells and surrounding hot spring waters in the western Unzen area","authors":"Akira Ueda ,&nbsp;Heejun Yang ,&nbsp;Yukiko Hoshino ,&nbsp;Sakurako Satake ,&nbsp;Dongyang Mao ,&nbsp;Amane Terai","doi":"10.1016/j.apgeochem.2025.106384","DOIUrl":"10.1016/j.apgeochem.2025.106384","url":null,"abstract":"<div><div>In areas of volcanic and geothermal activity, caprock and other impermeable layers regulate the flow direction of geothermal fluids. However, it is unclear how this impermeable layer was formed or at what depth. This impermeable layer is partly formed by carbonate minerals. In the Unzen area, the temperature logging results of geothermal wells showed that high temperature fluids move as lateral flow. In this study, we focused on the carbonate minerals in the area and determined the origin of the fluids from their isotope compositions. This study explores the formation mechanisms of carbonate layers through reactions between CO₂-rich water and rocks within a volcanic geothermal system. Samples were collected from two geothermal wells and adjacent hot spring water in the western Unzen area for chemical and isotope analysis. The UZ-7 well, located near Mt. Unzen, features carbonate mineral layers at depths of approximately −300 m and −600 m. The isotope compositions of carbon and oxygen within these layers indicate a magmatic origin for the carbon, with the fluid mixture consisting of meteoric water, magmatic fluid, and fossil seawater. Deep fluids in the western Unzen region likely undergo vapor–brine separation at about −600 m elevation, where vapor escapes as fumarole gas and hot spring water in the Unzen hot spring area. The brine, approximately 240 °C, then flows westward, emerging at Obama hot spring. This lateral movement and heating of surrounding strata to about 150 °C at depths of −300 m and −600 m facilitate extensive calcite precipitation (up to 100 m thick) through rock interactions nearing chemical equilibrium. This process also results in significant kaolinite and chlorite deposition, potentially forming two impermeable caprock layers. The UZ-4 well, situated 2 km west of UZ-7, also exhibits carbonate layers, albeit on a reduced scale, likely due to insufficient rock reactions from progressively cooler brine temperatures.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"185 ","pages":"Article 106384"},"PeriodicalIF":3.1,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143826357","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 colloidal transport of copper in partially remediated mine tailings by single particle analysis and transmission electron microscopy","authors":"Joel Kroeker ,&nbsp;Michael Schindler ,&nbsp;Richard Oliveira ,&nbsp;Feiyue Wang","doi":"10.1016/j.apgeochem.2025.106361","DOIUrl":"10.1016/j.apgeochem.2025.106361","url":null,"abstract":"<div><div>Abandoned mine tailings are an environmental and financial liability worldwide and require often extensive reclamation efforts. A combination of single particle analysis and transmission electron microscopy, along with bulk chemical analysis, ultracentrifugation and ultrafiltration, are used to decipher the chemical, mineralogical and colloidal composition of an abandoned gold mine tailings at the Nopiming Provincial Park, Manitoba, Canada. The tailings are the result of the discharge of chalcopyrite-rich mine waste and were in recent years partially reclaimed through capping of two ponds with dolomite- and organic-rich soils. The surficial layers at the fully and partially affected sites have higher pH, inorganic and organic carbon content than the underlying tailings, whereas the surficial tailings at the unaffected site are more acidic and depleted in Cu relative to the reduced zone occurring at greater depth. The speciation of Cu in extracted acidic leachates is characterized by Cu²⁺ and CuSO₄ species, whereas Cu-organic complexes only play a role in weak acidic leachates extracted from the fully affected site and the reduced layer at the unaffected site. Studies of the colloidal fraction indicate that many colloids are coated by organic- or silica-rich layers, which in combination with the pH control their zeta potential and aggregation. The number of particles per time interval and the relative standard deviation of the Cu concentration per particle increase at a higher rate with increasing concentration of Cu in the colloidal fraction. These correlations are explained with a greater increase in the proportions of colloids containing trace (e.g. biomass-based colloids) and minor (clay mineral-based colloids) amounts of Cu relative to colloids where Cu is a major element (Cu-sulfate bearing colloids). A comparison of the mineralogical and chemical composition of the tailings and their colloidal fractions indicates that the formation of Cu-bearing colloids is favored in partly neutralized tailings of weak acidic pH and in the absence of efflorescent salts.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"184 ","pages":"Article 106361"},"PeriodicalIF":3.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815985","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":"Water compositional evolution around a historic asbestos mine, Troodos mountains, Cyprus","authors":"Aled D. Evans ,&nbsp;Dave Craw ,&nbsp;Joanna L. Shannon ,&nbsp;Joseph Hattersley ,&nbsp;Lewis J.C. Grant ,&nbsp;Rosalind M. Coggon ,&nbsp;Damon A.H. Teagle","doi":"10.1016/j.apgeochem.2025.106387","DOIUrl":"10.1016/j.apgeochem.2025.106387","url":null,"abstract":"<div><div>The historic Amiantos chrysotile asbestos mine (closed 1988) in the Troodos mountains, is hosted in serpentinites that constitute the Artemis Diapir. Host rocks were extensively sheared and brecciated during Pleistocene-Holocene diapiric uplift, enabling penetration of meteoric waters. Veins of serpentine minerals, especially fibrous chrysotile, have formed throughout this uplift history with accompanying carbonates, and carbonate surface precipitates that form at spring sites. The Artemis Diapir is juxtaposed by faults against less-permeable partially serpentinised peridotites of the Olympus Diapir that forms the highest elevation (1952 m) of the Troodos Mountains. Streams and shallow groundwater draining the Artemis Diapir have high concentrations of Mg²⁺ and dissolved inorganic carbon (DIC), minor Ca²⁺, and pH 8–10. In addition, these waters have high concentrations of Na⁺, K⁺, Cl⁻, SO₄²⁻ and trace elements Cs, Ba, Br, B, and Li sourced from the dissolution of mineral inclusions in the host serpentinites. These dissolved constituents overprint low levels of marine aerosols that occur in local meteoric precipitation. Passage of surficial waters through asbestos mine tailings have locally enhanced dissolution of these elements because of even higher permeability and small particle size that resulted from mine-related comminution. All surficial waters are strongly supersaturated with respect to chrysotile (log Q/K = 3–9) and carbonate minerals, especially magnesite (log Q/K = 1–2). Evaporative carbonate precipitates form episodically on stream beds and tailings surfaces during dry seasons. Erosion of mine tailings and friable host rocks by rain events in the steep mountain environment contributes detrital chrysotile asbestos to stream sediments, with potential for aeolian remobilization. The relatively high abundance of carbonates already in the rocks and mine residues, combined with carbonate and chrysotile supersaturation in surficial waters, limits the efficacy of these materials for CO₂ capture through enhanced weathering and mineral carbonation.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"185 ","pages":"Article 106387"},"PeriodicalIF":3.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828810","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}