Geochemistry International最新文献

{"title":"Quartz Diorites of the Volkovsky Ore-Bearing Massif (Middle Urals, Russia): U–Pb Age, Nd–Sr–Pb Isotope Systematics, Geochemical Features, Petrogenetic, and Geodynamic Consequences","authors":"E. V. Anikina,&nbsp;N. M. Kudryashov,&nbsp;N. G. Soloshenko,&nbsp;I. A. Rusin,&nbsp;M. V. Chervyakovskaya","doi":"10.1134/S0016702924020022","DOIUrl":"10.1134/S0016702924020022","url":null,"abstract":"<div><p>The paper reports the results of U–Pb dating, Nd–Sr–Pb isotope systematics, and geochemical study of quartz diorites associated with ore-bearing (Cu–Pd–Au–Ag) gabbro of the Volkovsky massif, which is localized within the Urals Platinum Belt, at its eastern border with the Silurian–Devonian volcanogenic complexes of the Tagil megazone. The age of the quartz diorites according to U–Pb (TIMS) dating is 429 ± 9 Ma, MSWD = 0.009. Sr–Nd–Pb isotope characteristics (ε_Nd(T) = +5.5…+6.7; (⁸⁷Sr/⁸⁶Sr)_t = 0.70382–0.70392; ²⁰⁶Pb^/204Pb = 18.38–18.57; ²⁰⁷Pb/²⁰⁴Pb = 15.56–15.58; ²⁰⁸Pb/²⁰⁴Pb = 38.14–38.30) indicate a juvenile source with a model age of 570–760 Ma. The obtained data fall within values typical of basalts of ensimatic island arcs. The geochemical features of the granitoids of the Volkovsky massif (low REE concentration, differentiated REE pattern (La/Yb = 8–14) with a weak positive Eu anomaly (Eu/Eu* = 0.9–1.4)) are consistent with the characteristics of melts obtained in experiments on hydrous melting of mafic rocks in equilibrium with amphibole–pyroxene residue. The anomalous concentration of strontium (more than 1000 ppm) in the quartz diorites is due to the high content of this element in a source. Such source could be the oldest rocks of the Urals Platinum Belt—olivine gabbro and metamorphic rocks of their surroundings. The identical ages of the quartz diorites of the Volkovsky massif and monzonitoids of the Kushvinsky massif allow us to consider these rocks as the result of the almost simultaneous mantle and crust melting at the final stage of the formation of the Tagil island-arc system.</p></div>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 2","pages":"155 - 171"},"PeriodicalIF":0.7,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140567858","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":"Major, Volatile, Ore, and Trace Elements in Magmatic Melts in the Earth’s Dominant Geodynamic Settings. II. Similarities and Differences","authors":"V. B. Naumov,&nbsp;A. V. Girnis,&nbsp;V. A. Dorofeeva","doi":"10.1134/S0016702924010075","DOIUrl":"10.1134/S0016702924010075","url":null,"abstract":"<p>Based on the mean contents of elements and their standard deviations estimated in the first part of this contribution (Naumov et al., 2023), we compared in detail the geodynamic settings distinguished earlier. In order to compare the compositions of mafic melts, a correction was introduced for changes related to the fractionation of the main minerals. Using numerical criteria, the elements were arranged in a sequence of the increasing degree of compatibility during melting and crystallization, and regular variations in element contents normalized to the mean composition of oceanic-island melts were distinguished. The melts of mid-oceanic ridges show a monotonous increase in normalized contents from the most incompatible (Cs, Ba, U, La, etc.) to compatible elements (Sc, Ni, and Cr). The settings of convergent plate boundaries show relative enrichment in the most incompatible elements and significant negative Ta−Nb anomalies relative to neighboring elements. The magmas of continental rifts show the most significant enrichment in the most incompatible elements, as well as Pb, Li, and some other elements. Indicator element ratios showing significant variations between the settings were distinguished for mafic melts. Some element ratios are almost identical (within observed variations) in mafic melts from all the settings. The mean element ratios in mafic, intermediate, and silicic magmas show three types of behavior. Some ratios (including the canonic ratios Nb/Ta, Zr/Hf, etc.) in intermediate and silicic magmas are inherited from the composition of mafic melts. Some ratios show irregular changes from mafic to silicic melts (Sr/Cr, F/Th, etc.). Some other ratios change monotonously and significantly in the sequence from mafic to silicic melts (Ni/Yb, Lu/P, etc.). The variations in element ratios are related to the crystallization differentiation of melts and contributions of geochemically contrasting reservoirs.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"18 - 31"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140524970","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":"High-Precision Determination of Carbon Isotope Composition and Concentration of Dissolved Inorganic Carbon in Seawater","authors":"E. O. Dubinina,&nbsp;S. A. Kossova,&nbsp;Yu. N. Chizhova","doi":"10.1134/S0016702924010038","DOIUrl":"10.1134/S0016702924010038","url":null,"abstract":"<p>Determination of the isotopic composition and concentration of dissolved inorganic carbon (DIC) in sea water requires not only high measurement accuracy, but also the development of unified approaches to data standardization and material collection. In this work, we studied the effect of sampling methods (“into containers” and “into vials with acid”) with and without the addition of a toxin) on the results of determining the values of δ¹³С(DIC) and the concentration of DIC in sea water. The analytical protocol is described in detail, based on many years of experience in the sample collection, measurement and standardization of data obtained for a large number of water samples of the Arctic seas. According to the above protocol, the values of δ¹³С(DIC) and [DIC] can be determined with an error of less than 0.05‰ (1σ) and 4.5 rel % respectively. It has been shown that sampling “in a vial with acid” with their storage for 4 months is accompanied by significant contamination by atmospheric carbon dioxide with an underestimation of δ¹³С(DIC) values by an average of 0.3–0.8‰ and an overestimation of [DIC] values by an average of two times. The absence of a toxin that stops biological activity does not lead to significant shifts in the DIC concentration, but it strongly affects the δ¹³С(DIC) values, which become underestimated by an average of 1‰. Using sampling “in a container” and toxin addition, along with following other recommendations, the samples retain the isotope and concentration parameters of DIC throughout the year.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"45 - 54"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140516309","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":"Oceanic Crust Formation within the Andrew Bain Fault Zone, Southwest Indian Ridge: Petrological and Geochemical Evidence","authors":"N. M. Sushchevskya,&nbsp;V. D. Scherbakov,&nbsp;A. A. Peyve,&nbsp;E. P. Dubinin,&nbsp;B. V. Belyatsky,&nbsp;A.V. Zhilkina","doi":"10.1134/S0016702924010026","DOIUrl":"10.1134/S0016702924010026","url":null,"abstract":"<div><p>Petrogeochemical data on basalts (lithophile elements and Sr–Nd–Pb isotopes, liquidus olivine and spinel compositions) from the transition zone of the Southwest Indian Ridge (SWIR) in the Du Toit–Andrew Bain fault zone indicate significant differences in their composition. Tholeiites enriched in Na and depleted in Fe (Na-TOR genetic type) are developed within the rift valley adjacent to the faults. Deep-type basalts (TOR-1) are present in the western wall of the Andrew Bain Fault. The outpouring of these magma types reflects a possible change in geodynamic setting during formation of this zone: from deep and high temperature to shallower magma generation conditions (Sushchevskaya et al., 2022). Differences in the primary melts of tholeiites from the rift valley and the Andrew Bain Transform Fault are also traced in the composition of liquidus olivine. The olivines from rift valley are similar to the typical Na-TOR olivines with Mg number of Fo_88-87, low Ni and elevated Mn contents. On the contrary, olivines in tholeiite from the Andrew Bain Fault Zone are enriched in Ni and depleted in Mn, which may indicate the involvement of pyroxenite in melt generation. This component is either oceanic lithosphere recycled through the deep mantle or fragments of previously formed oceanic crust, which were subsequently involved in melting during the spreading axes jumping. A similar process is typical of the Bouvet Triple Junction, where the trace-element composition of olivine shows significant heterogeneity. The radiogenic composition of Pb and Sr of the Andrew Bain Fault tholeiites are similar to those of enriched magmas from such Indian Ocean rises as Crozet, Marion and Bouvet, but differ from those of the Conrad and Af. Nikitin rises. The source of such tholeiite melts is close in composition to the model HIMU type (with high U/Pb), which likely contains an admixture of EM-II component (with elevated Rb/Sr).</p></div>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"1 - 17"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140525887","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":"Geochemical Features of the Talus–Lacustrine Sedimentogenesis in the Chistoye Lake Basin, Northern Okhotsk Region","authors":"P. S. Minyuk,&nbsp;D. K. Pozhidaeva,&nbsp;O. T. Sotskaya,&nbsp;S. S. Burnatny","doi":"10.1134/S0016702924010051","DOIUrl":"10.1134/S0016702924010051","url":null,"abstract":"<div><p>The results of the geochemical study of loose sediments of the catchment basin and bottom sediments of Lake Chistoye located in the Northern Okhotsk region showed that the lake was formed at the beginning of the Early Holocene about 11200 cal. years BP. It is dominated by terrigenous sedimentation, i.e. the geochemical characteristics of sediments are controlled by the grain size. Fine-grained sediments have low SiO₂, Na₂O, K₂O, CaO, Sr contents and are enriched in Al₂O₃, TiO₂, MgO, Fe₂O₃, and V. Changes in the sedimentation nature are likely caused by climatic reasons and may be associated with the cold Bond events. In the Early Holocene, mostly thin silts were deposit in Lake Chistoye. The pulses of “coarse-grained” sediments (&gt;140 μm) enriched with silica occurred (9760–9650) and 8810 cal years BP. Relatively coarse-grained sediments were mainly accumulated at the very beginning of the Middle Holocene 8540–6920 cal years BP, as well as 6140 and 4450 cal years BP. In the Late Holocene, the input of detrital material with increased SiO₂ contents was noted in the range of 3470–850 cal. years BP.</p></div>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"79 - 98"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140516719","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":"Peritectic Reaction of Olivine in the Carbonate–Silicate–(C–O–H) Diamond-Forming System at 6 GPa","authors":"A. V. Kuzyura,&nbsp;A. V. Spivak,&nbsp;Yu. A. Litvin","doi":"10.1134/S001670292401004X","DOIUrl":"10.1134/S001670292401004X","url":null,"abstract":"<p>The influence of the components of supercritical C–O–H fluid (at a content of 7.5 wt %) on the melting relations in the multicomponent diamond-forming system olivine–jadeite–diopside–(Mg–Fe–Ca–Na carbonates)–(C–O–H) was studied experimentally at 6 GPa and 700–1200°C under the conditions of the upper mantle. The peritectic reaction of olivine and jadeite-bearing melt with the formation of garnet was suggested as a key mechanism for the ultramafic–mafic evolution of diamond-forming melts. The CO₂ component of the C–O–H fluid reacts with silicate components to form carbonates. The H₂O component, together with carbonate compounds of the diamond-forming system, reduces the temperature of its liquidus and solidus boundaries significantly. After the completion of crystallization of a completely miscible silicate–carbonate–(C–O–H fluid) melt, a phase of supercritical aqueous fluid and hydrous carbonate nesquehonite MgCO₃·3H₂O identified by Raman spectroscopy appear in the subsolidus of the diamond-forming system.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"32 - 44"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140523803","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":"Role of Biochemical Processes in the Formation of Waters and Bottom Sediments after Reduction in the Anthropogenic Pollution","authors":"T. I. Moiseenko,&nbsp;E. O. Leummens","doi":"10.1134/S0016702924010063","DOIUrl":"10.1134/S0016702924010063","url":null,"abstract":"<p>The paper is devoted to anthropogenic and biogeochemical processes that effect the formation of the water and bottom sediment (BS) of subarctic Imandra Lake. The data of long-term observations are presented that show changes in the chemical composition of the water during the period of maximum pollution and after the reduction in the anthropogenic load over the past 30 years. The concentrations of toxic metals in the water has decreased, but climate warming has increased the inflow of organic matter and nutrients, and this intensified the production processes. The enrichment of the water in heavy metals during the period of intense pollution resulted in the accumulation of these metals in the bottom sediments, with the highest concentrations of the metals found in the uppermost layers accumulated during the modern sedimentation period. The development of anoxic conditions in the bottom water horizons due to sedimentation and oxidation of organic matter leads to the circulation of metals and hampers their burial. Physicochemical and biogeochemical processes are considered as explaining the diffusion of metals to the surface of the bottom sediments and the accumulation of anomalously high concentrations of metals in the surface layers of BS despite the significant decrease in the concentrations of metals in water. A hypothesis is suggested for the beginning of initial diagenesis stage in bottom sediments.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"67 - 78"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140525500","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":"Changes in the Provenance of the Holocene Deposits of the Oga and Tsivolki Bays (Novaya Zemlya Archipelago) according to Sr, Nd, and Pb Isotope Data","authors":"I. A. Vishnevskaya,&nbsp;Yu. A. Kostitsyn,&nbsp;T. G. Okuneva,&nbsp;N. G. Soloshenko","doi":"10.1134/S0016702924010087","DOIUrl":"10.1134/S0016702924010087","url":null,"abstract":"<p>The paper considers Sr, Nd, and Pb isotope data obtained for two cores of bottom sediments taken in the Oga and Tsivolki bays of Severny Island of the Novaya Zemlya archipelago. The studied sequence of sediments from Oga Bay has accumulated over the last thousand years. The ⁸⁷Sr/⁸⁶Sr ratio decreases from top to bottom down the section from 0.72225 to 0.71995, the value of ε_Nd varies from –6.1 to –5.5. The Pb isotopic composition varies within narrow limits: the ²⁰⁶Pb/²⁰⁴Pb ratio from 19.107 to 19.139, the ²⁰⁷Pb/²⁰⁴Pb ratio from 15.632 to 15.635, and the ²⁰⁸Pb/²⁰⁴Pb ratio from 38.568 to 38.635. A rapid decrease in the ⁸⁷Sr/⁸⁶Sr ratio at a relatively stable neodymium and lead isotope composition indicates a change in the source of the clastic material. This can be explained by the fact that the material of the destruction of Permian clay shales, and then Devonian–Silurian sedimentary carbonates, first entered the area of glacier abrasion and further, respectively, into the sedimentation zone. The sediment column from Tsivolki Bay was formed over a little more than 10 000 years. Based on the Sr, Nd, and Pb isotope ratios, these bottom sediments are divided into lower and upper parts: before and after 150 cm (or ~3500 years). In the lower part of the column, the ⁸⁷Sr/⁸⁶Sr ratio increases from 0.72055 to 0.72580, the value of ε_Nd remains approximately the same and varies around –8.2. In the upper part, the ⁸⁷Sr/⁸⁶Sr ratio drops to 0.72049 in the near-surface layer; at the same time, the value of ε_Nd increases to –6.4. At the boundary of these two units, the ²⁰⁶Pb/²⁰⁴Pb ratio abruptly changes from about 18.0 in the lower part to 19.3 in the upper part and ²⁰⁸Pb/²⁰⁴Pb from about 36.5 in the lower part to 38.7 in the upper part of the section. The change in the Sr, Nd, and Pb isotope characteristics is likely a reflection of changes in the composition of the rocks in the area where the basin was removed, which is now being eroded by the glacier. Comparison with modern sources supplying clastic material to the Kara Sea showed that the material is supplied to the Oga and Tsivolki bays only from Novaya Zemlya.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 1","pages":"55 - 66"},"PeriodicalIF":0.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140518148","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":"Geothermal Development Model in Granite Area: a Case Study of Shangyun Area, Yunnan Province, China","authors":"Sun Yuhang,&nbsp; Zhang Jinchuan,&nbsp; Xu Longfei,&nbsp; Li Jie,&nbsp; Li Qianchao,&nbsp; Chen Lei,&nbsp; Zhao Xingxu,&nbsp; Li Wei","doi":"10.1134/S0016702923700180","DOIUrl":"10.1134/S0016702923700180","url":null,"abstract":"<p>The Shangyun area is classified as a medium-high temperature geothermal region situated in western Yunnan, inside the tropical zone of Yunnan and Tibet. Granites exhibit a wide distribution, while active faults demonstrate a rather advanced state of development. Consequently, the geological conditions are favourable for the creation of geothermal resources. Drawing upon previous research findings and geothermal drilling data, this study undertakes an analysis of the principal geological factors contributing to the development of the Shangyun geothermal system in Yunnan. The investigation reveals several noteworthy characteristics of geothermal activity within the granite region, including proximity to heat sources, substantial thermal gradients, water accumulation within fractures, the coexistence of deep and shallow geothermal phenomena, and the occurrence of hot springs along extensive and profound fault lines. The determined ground heat flow value in the Shangyun area is 142.74 mW/m², with its primary heat source being predominantly influenced by high mantle heat flow and the radioactive heat generation of the Lincang granite located in the eastern region with the mean rate of radioactive heat generation of 7.6 μW/m³. The reservoir space mostly consists of weathered crust and fracture type heat storage. Additionally, the upper Jurassic mudstone, which has a thickness ranging from 500 to 1000 m and a thermal conductivity of 2.39 W/(m K), serves as an effective regional cap layer. The dissolution of silicate has a significant impact on the composition of geothermal water, with the primary type being HCO₃–Na. The process of atmospheric precipitation infiltration and recharge contributes significantly to the availability of ample water resources for geothermal systems. Based on an analysis of the electrical data pertaining to the region, it can be inferred that the primary source of the water supply originates from the eastern mountain. Furthermore, it is seen that the active fault serves as the conduit for the deep circulation of geothermal water. This study presents a comprehensive examination of several geothermal geological features, including heat source, heat storage, hot channel, and geothermal water, in order to build a geothermal model specific to the Shangyun region.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 5","pages":"500 - 519"},"PeriodicalIF":0.7,"publicationDate":"2024-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754192","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":"Impact of Irrigation on Arsenic Mobilization in Groundwater from the Hetao Plain, Northern China: Evidence from Cl/Br Ratios and Stable Isotopes","authors":"Yihui Dong,&nbsp; Shiyi Zhu,&nbsp; Yapeng Xie,&nbsp; Ying Wang,&nbsp; Shuanglei Huang,&nbsp; Jiale Li","doi":"10.1134/S0016702923700192","DOIUrl":"10.1134/S0016702923700192","url":null,"abstract":"<p>The Hetao Plain, located in western Inner Mongolia, China, has been used for irrigation since the second century BC. Sixty-five samples were collected, including fifty-nine groundwater and six surface water samples, for hydrochemical and oxygen and hydrogen stable isotope analysis to assess the impact of irrigation on arsenic mobilization in groundwater in the study area. The total dissolved arsenic concentration in groundwater and surface water ranged from 3.2 to 764.8 μg/L and from 6.2 to 11.2 μg/L, respectively, generally exceeding 50 μg/L in groundwater, where the reducing environment prevails. The primary groundwater recharge source was a shallow aquifer that receives a considerable amount of irrigation water. The high arsenic content in groundwater was attributed to hydrochemical processes caused by vertical leaching of dissolved halite from the unsaturated zone, which was determined based on the molar Cl/Br ratios analysis. The oxygen and hydrogen stable isotope analysis of groundwater demonstrated the mixing between the groundwater and Yellow River water. An association between lateral recharge and mixing, evaporation, leaching, vertical mixing, and arsenic enrichment in groundwater was established based on the correlation between Cl^– concentration and δ¹⁸O values. In an anaerobic groundwater environment, nitrate from nitrogen fertilizers indirectly oxidized As(III) to As(V).</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 5","pages":"547 - 560"},"PeriodicalIF":0.7,"publicationDate":"2024-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754130","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}