Aquatic Geochemistry最新文献

{"title":"Tufa Deposition Dynamics in a Freshwater Karstic Stream Influenced by Warm Springs","authors":"Dorothy J. Vesper,&nbsp;Johnathan E. Moore,&nbsp;Harry M. Edenborn","doi":"10.1007/s10498-019-09356-9","DOIUrl":"https://doi.org/10.1007/s10498-019-09356-9","url":null,"abstract":"<p>Sweet Springs Creek, located in the Valley and Ridge Province of the Appalachian Mountains in southeastern West Virginia and southwestern Virginia, USA, contains major fluvial tufa formations at the sites of localized fractures and faults. Sweet Springs Creek receives input from higher-temperature thermal springs of lower pH and higher sulfate concentration that differ significantly in chemical composition due to differences in the underlying geology. In this study, theoretical rates of tufa accumulation were compared with those measured on travertine tiles left in situ for 30?days during periods of high and low stream flow above and below the sites of major fluvial tufa formations. Consistent with the chemistry of the spring waters, observed and predicted tufa accumulation rates in the stream were low compared to others reported worldwide. Tufa formation rate estimates were consistently higher during seasonal conditions of low flow, warm temperatures, and higher pH that occurred in late summer, but net annual accumulation may still be zero or less due to formation erosion during periodic flooding events. Computer tomography analysis determined that the natural porosity of travertine tiles results in a total surface area 32% greater than that calculated based solely on tile dimensions, which may overestimate initial tufa accumulation rates in situ. Measured rates of carbonate deposition on travertine tiles were 1.6–82?× lower than rates predicted based on theoretical models, consistent with the hypothesis of rate reduction due to variable diffusional boundary layer limitations and variability in stream hydrology. The generation of loose, platy, and unconsolidated precipitate on tiles under geochemical conditions predicted to be the greatest for optimal tufa formation suggested that the precipitation of particulate calcite in the stream system may predominantly result in the formation of unconsolidated marl deposits.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 3-4","pages":"109 - 135"},"PeriodicalIF":1.6,"publicationDate":"2019-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09356-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4741416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multicomponent Versus Classical Geothermometry: Applicability of Both Geothermometers in a Medium-Enthalpy Geothermal System in India","authors":"Sitangshu Chatterjee,&nbsp;U. K. Sinha,&nbsp;B. P. Biswal,&nbsp;Ajay Jaryal,&nbsp;Suraj Patbhaje,&nbsp;Ashutosh Dash","doi":"10.1007/s10498-019-09355-w","DOIUrl":"https://doi.org/10.1007/s10498-019-09355-w","url":null,"abstract":"<p>The Manuguru geothermal area, located in the Khammam district of Telangana state, India, is one of the least explored medium-enthalpy geothermal systems in India. In this study, subsurface reservoir temperature was estimated by applying various methodologies such as chemical geothermometry, multicomponent geothermometry and mixing models. Chemical geothermometers provided wide range in temperature estimation, and most of them (Na–K, Na–K–Ca, Mg-corrected Na–K–Ca) were found to be unsuitable for predicting reservoir temperature due to the absence of attainment of equilibrium between suitable mineral pairs. The temperature range estimated from the quartz geothermometers varied from 72 to 120?°C which matched closely with values obtained from K–Mg geothermometers. To overcome this problem and to better constrain the reservoir temperature, multicomponent solute geothermometry modelling was carried out by applying the GeoT computer code. Fluid reconstruction was done after taking into account both the degassing and mixing phenomena. GeoT modelling of the reconstructed fluid provided excellent clustering of the minerals. From the GeoT modelling study, it was found that minerals like quartz, chalcedony, calcite, etc., attained simultaneous equilibrium with thermal waters in the temperature range of 130?±?10?°C, which can be taken as the most probable reservoir temperature. The subsurface temperature (137?°C) obtained from the mixing model further validated the results obtained from multicomponent geothermometry. This integrated multicomponent method and the simulation program used in this study take into account various processes (i.e. mixing, degassing, non-attainment of equilibrium, etc.) which affect the composition of the thermal fluids during its ascent to the surface. The statistical approach of ‘best clustering minerals’ used in this model helps to overcome the problems encountered in applying cation or single-component geothermometers in the medium-enthalpy geothermal systems.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 3-4","pages":"91 - 108"},"PeriodicalIF":1.6,"publicationDate":"2019-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09355-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4368181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isotopic Composition and Origin of Sulfide and Sulfate Species of Sulfur in Thermal Waters of Jiangxi Province (China)","authors":"Svetlana V. Borzenko,&nbsp;Elena V. Zippa","doi":"10.1007/s10498-019-09353-y","DOIUrl":"https://doi.org/10.1007/s10498-019-09353-y","url":null,"abstract":"<p>The reduced sulfur species, sulfide, elemental and thiosulfate were considered in the thermal waters of Jiangxi Province for the first time. It is shown that the sulfur speciation content significantly varies and depends on the pH values. The major part of reduced sulfur refers to sulfide species in the nitric thermal waters, to elemental—in the carbon dioxide thermal waters. The presence of both reduced and oxidized sulfur speciation indicates the possibility of sulfide minerals hydrolysis and disproportionation of the product of this reaction (SO₂) with the participation of hot water with the formation of elemental and sulfate sulfur. The isotopic composition of dissolved sulfate and sulfide sulfur speciation has shown that the process of bacterial reduction proceeds in the thermal waters, accompanied by accumulation of relatively heavy sulfur isotope in sulfates. Simultaneously with reduction, the oxidation of both sulfide minerals and newly formed hydrosulfide proceeds with formation of elemental, thiosulfates and also sulfates in the discharge zone was proceeded. It is shown that the process of sulfide oxidation mostly occurs in carbon dioxide thermal waters. Therefore, the elemental sulfur is predominant in carbon dioxide waters. The oxidation process is less significant in the nitric thermal waters, whereby the concentrations of sulfide ion are higher than sulfates. The ambiguous effect of sulfate reduction on the hydrogeochemical environment of the thermal waters is confirmed by the differing value of the carbon isotope ratio of HCO₃^? in the considered waters. The obtained isotopic composition data ³⁴δS(SO₄^2?) indicate host rocks as a source of sulfates in the thermal waters of Jiangxi Province.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 1-2","pages":"49 - 62"},"PeriodicalIF":1.6,"publicationDate":"2019-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09353-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4543619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Integrated Isotope-Geochemical Approach to Characterize a Medium Enthalpy Geothermal System in India","authors":"Sitangshu Chatterjee,&nbsp;Uday K. Sinha,&nbsp;Bishnu P. Biswal,&nbsp;Ajay Jaryal,&nbsp;Pankaj K. Jain,&nbsp;Suraj Patbhaje,&nbsp;Ashutosh Dash","doi":"10.1007/s10498-019-09352-z","DOIUrl":"https://doi.org/10.1007/s10498-019-09352-z","url":null,"abstract":"<p>The Manuguru geothermal area, situated in the Telangana state, is one of the least explored geothermal fields in India. In this study, the chemical characteristics of the groundwater (thermal and non-thermal waters) are investigated to elucidate the source of the solutes dissolved in the water and to determine the approximate residence time of the thermal waters. The major hydrogeochemical processes controlling the groundwater geochemistry have been deciphered using multivariate statistical analysis, conventional graphical plots and geochemical modelling (PHREEQC). Geochemically different groundwater clusters (bicarbonate type, bicarbonate–chloride type and chloride type) can clearly be identified from the chemometric analysis, i.e. PCA and HCA. Thermal waters are mostly Na–HCO₃ type having low EC and TDS compared to non-thermal groundwaters. Silicate weathering and ion exchange mainly contribute to the dissolved ion budget in the groundwater of the study area. The carbon isotopic composition of DIC (δ¹³C) points to silicate weathering with soil CO₂ coming from C₃ type of plants. Stable isotopes (δ¹⁸O, δ²H) data confirm the meteoric origin of the thermal waters with no oxygen-18 shift. The low tritium values of the thermal water samples reveal the long circulation time (&gt;?50?years) of the recharging waters. Radiocarbon dating (¹⁴C) shows that the approximate residence time of the thermal waters ranges from 9952 to 18,663?year BP (before present).</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 1-2","pages":"63 - 89"},"PeriodicalIF":1.6,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09352-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4990140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry of Chilean Rivers Within the Central Zone: Distinguishing the Impact of Mining, Lithology and Physical Weathering","authors":"J. Viers,&nbsp;S. Carretier,&nbsp;Y. Auda,&nbsp;O. S. Pokrovsky,&nbsp;P. Seyler,&nbsp;F. Chabaux,&nbsp;V. Regard,&nbsp;V. Tolorza,&nbsp;G. Herail","doi":"10.1007/s10498-019-09350-1","DOIUrl":"https://doi.org/10.1007/s10498-019-09350-1","url":null,"abstract":"<p>Several rivers of Chile from the latitude 30°–38° have been sampled during a stable anticyclonic period (October 2008). Firstly, our aim was to evaluate the dissolved chemical composition (major and trace elements) of poorly known central Chilean rivers. Secondly, we used a co-inertia analysis (see Dolédec and Chessel in Freshw Biol 31:277–294, 1994) to explore the possible relationships between the concentrations of elements and the environmental parameters [surface of the basin (km²)/mining activity (%)/average height (m)/watershed mean slope (%)/% of the surface covered by vegetation, sedimentary rocks, volcano-sedimentary rocks, volcanic rocks, granitoid rocks/erosion rate (mm/year)]. Globally, the major elements concentration could be explained by a strong control of mixed silicate and carbonate and evaporate lithology. The statistical treatment reveals that the highest metal and metalloids loads of Tinguiririca, Cachapoal, Aconcagua, Choapa, Illapel and Limari could be explained by the contribution of the mining activities in the uppermost part of these watersheds and/or by the higher geochemical background. Indeed, it remains difficult to decipher between a real mining impact and a higher geochemical background. Even if these rivers could be impacted by AMD process, the size of these watersheds is capable of diluting AMD waters by the alkaline character of tributaries that induce acid neutralization and decrease the level of metals and metalloids.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 1-2","pages":"27 - 48"},"PeriodicalIF":1.6,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09350-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4796533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Speciation and Mobility of Mn and Fe in Estuarine Sediments","authors":"Véronique E. Oldham,&nbsp;Matthew G. Siebecker,&nbsp;Matthew R. Jones,&nbsp;Alfonso Mucci,&nbsp;Bradley M. Tebo,&nbsp;George W. Luther III","doi":"10.1007/s10498-019-09351-0","DOIUrl":"https://doi.org/10.1007/s10498-019-09351-0","url":null,"abstract":"<p>Dissolved and solid-phase speciation of Mn and Fe was measured in the porewaters of sediments recovered from three sites in the Greater St. Lawrence Estuary: the Saguenay Fjord, the Lower St. Lawrence Estuary (LSLE) and the Gulf of St. Lawrence (GSL). At all sites and most depths, metal organic ligand complexes (Mn(III)–L and Fe(III)–L) dominated the sedimentary porewater speciation, making up to 100% of the total dissolved Mn or Fe. We propose that these complexes play a previously underestimated role in maintaining oxidized soluble metal species in sedimentary systems and in stabilizing organic matter in the form of soluble metal–organic complexes. In the fjord porewaters, strong (log <i>K</i>_COND?&gt;?13.2) and weak (log <i>K</i>_COND?&lt;?13.2) Mn(III)–L complexes were detected, whereas only weak Mn(III)–L complexes were detected at the pelagic and hemipelagic sites of the GSL and LSLE, respectively. At the fjord site, Mn(III)–L complexes were kinetically stabilized against reduction by Fe(II), even when Fe(II) concentrations were as high as 57?μM. Only dissolved Mn(II) was released from the sediments to overlying waters, suggesting that Mn(III) may be preferentially oxidized by sedimentary microbes at or near the sediment–water interface. We calculated the dissolved Mn(II) fluxes from the sediments to the overlying waters to be 0.24?μmol?cm^?2?year^?1 at the pelagic site (GSL), 11?μmol?cm^?2?year^?1 at the hemipelagic site (LSLE) and 2.0?μmol?cm^?2?year^?1 in the fjord. The higher benthic flux in the LSLE reflects the lower oxygen concentrations (dO₂) of the bottom waters and sediments at this site, which favor the reductive dissolution of Mn oxides as well as the decrease in the oxidation rate of dissolved Mn(II) diffusing through the oxic layer of the sediment and its release to the overlying water.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"25 1-2","pages":"3 - 26"},"PeriodicalIF":1.6,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09351-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4619378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Hydrogeochemical Processes for Waters’ Chemical Composition and Stable Isotope Investigation of Groundwater/Surface Water in Karst-Dominated Terrain, the Upper Tigris River Basin, Turkey","authors":"E. Dişli","doi":"10.1007/s10498-019-09349-8","DOIUrl":"https://doi.org/10.1007/s10498-019-09349-8","url":null,"abstract":"<p>The Upper Tigris River Basin is one of the biggest basins in Turkey, where municipal, agricultural and industrial water supplies are highly dependent on groundwater and surface water resources. The interpretation of plots for different major ions indicates that the chemical compositions of the surface/groundwater in the Upper Tigris River Basin are dominated Ca²⁺, Mg²⁺, HCO₃^? and SO₄^2? which have been arisen largely from chemical weathering of carbonate and evaporate rock, and reverse ion exchange reactions. Isotopic composition of surface and groundwater samples is influenced by two main air mass trajectories: one originating from the Central Anatolia that is cold and rainy and another originating from the rains falling over northeastern Syria that is warm and rainy, with warm winds. The relative abundance of cations and anions in water samples is in the order: Ca^2+??&gt;?Mg^2+??&gt;?Na^+??&gt;?K⁺ for cations and HCO<span>\u0000 ^???₃\u0000 \u0000 </span>&gt;?Cl^??&gt;?SO₄^2?, respectively. Majority of the water samples are plotted on a Piper diagram showing that the chemical composition of the water samples was predominantly Ca–Mg–HCO₃ type. Groundwater and surface water have an average (Ca^2+?+?Mg²⁺/2HCO₃^?) ratio of 0.65 and 0.74, indicating no significant difference in their relative solute distribution and dissolution of carbonate rock (calcite and dolomite) predominantly by carbonic acid. The Mg²⁺/Ca²⁺ and Mg²⁺/ HCO₃^? molar ratio values are ranging from 0.21 to 1.30 and 0.11 to 0.47 for the groundwater and from 0.13 to 2.46 and 0.10 to 0.61 for the surface water samples, respectively,?indicating?that significant contribution of dolomite?dissolution has a higher advantage over limestone within the Upper Tigris River Basin.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"24 5-6","pages":"363 - 396"},"PeriodicalIF":1.6,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09349-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5000980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acknowledgement to Reviewers 2018","authors":"","doi":"10.1007/s10498-019-09348-9","DOIUrl":"https://doi.org/10.1007/s10498-019-09348-9","url":null,"abstract":"","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"24 5-6","pages":"397 - 397"},"PeriodicalIF":1.6,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-019-09348-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4895079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Biochar Carbon by Fluorescence and Near-Infrared-Based Chemometrics","authors":"Minori Uchimiya,&nbsp;Alan J. Franzluebbers,&nbsp;Zhongzhen Liu,&nbsp;Marshall C. Lamb,&nbsp;Ronald. B. Sorensen","doi":"10.1007/s10498-018-9347-9","DOIUrl":"https://doi.org/10.1007/s10498-018-9347-9","url":null,"abstract":"<p>Large-scale biochar field trials have been conducted worldwide to test for “carbon negative strategy” in the event of carbon credit and if other subsidies become enacted in the future. Once amended to the soil, biochar engages in complex organo-mineral interactions, fragmentation, transport, and other aging mechanisms exhibiting interactions with treatments including the irrigation and fertilizer application. As a result, quantitative tracing of biochar carbon relying on the routinely measured soil parameters, e.g., total/particulate organic carbon, poses a significant analytical uncertainty. This study utilized two biochar field trial sites to calibrate for the biochar carbon structure and quantity based on the infrared- and fluorescence-based chemometrics: (1) slow pyrolysis biochar pellets on kaolinitic Greenville fine sandy loam in Georgia and (2) fast pyrolysis biochar powder on Crider silt loam in Kentucky. Partial least squares-based calibration was constructed to predict the amount of solvent (toluene/methanol)-extractable fluorescence fingerprint (290/350?nm excitation and emission peak) attributed to biochar based on the comparison with the authentic standard. Near-infrared-based detection was sensitive to the C–H and C–C bands, as a function of biochar loading and the particulate organic carbon content (&lt;?53 μm) of the bulk soil. Developed chemometrics could be used to validate tarry carbon structures intrinsic to biochar additives, as the impact of biochar additives on soil chemical properties (pH, electric conductivity, and dissolved organic carbon) becomes attenuated over time.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"24 5-6","pages":"345 - 361"},"PeriodicalIF":1.6,"publicationDate":"2019-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-018-9347-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4571183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 in a Small Eastern Mediterranean Karst Watershed (Nahr Ibrahim, Lebanon)","authors":"N. Hanna,&nbsp;B. Lartiges,&nbsp;V. Kazpard,&nbsp;E. Maatouk,&nbsp;N. Amacha,&nbsp;S. Sassine,&nbsp;A. El Samrani","doi":"10.1007/s10498-018-9346-x","DOIUrl":"https://doi.org/10.1007/s10498-018-9346-x","url":null,"abstract":"<p>Watersheds located in semiarid areas such as the eastern Mediterranean are particularly sensitive to the impact of climate change. To gain knowledge on the hydrogeochemical processes occurring in the Nahr Ibrahim watershed, a Critical Zone Observatory in Lebanon, we analyze the isotopic composition of the river water as well as the concentrations of the major ions exported (Ca²⁺, Mg²⁺, HCO₃^?, Na⁺, Cl^?, K⁺, SO₄^2?). Sampling campaigns were conducted from March 2014 to August 2016 to capture contrasting hydrological conditions. The results indicate that the carbonate lithology of the watershed is the predominant source of Ca²⁺, Mg²⁺ and HCO₃^?, whereas the low contents of Na⁺, Cl^?, K⁺, SO₄^2? mainly originate from sea spray. Except in the headwaters, the Nahr Ibrahim River is oversaturated with respect to calcite and dolomite. During wet seasons, calcite weathering and dolomite weathering contribute in an equivalent manner to the solute budget, whereas during dry seasons, calcite precipitates in the river. The isotopic composition of the river water reveals little seasonal dependency, the groundwater recharge by snowmelt infiltration leading to spring waters depleted in heavier isotopes during the dry seasons. A carbonate weathering rate of about 176?t/km²/year was determined at the outlet of the Nahr Ibrahim watershed. The calculated values of CO₂ partial pressure, on average twice the atmospheric pressure, suggest that the river is a significant source of CO₂ to the atmosphere (111?t/year).</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"24 5-6","pages":"325 - 344"},"PeriodicalIF":1.6,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-018-9346-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4567339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}