Geochemistry International最新文献

{"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}

{"title":"Geochemistry and Fertility Assessment of Sub-Volcanic Rocks from the Bam Area, North of the Kerman Magmatic Copper Belt, SE Iran","authors":"Mirmohammad Miri,&nbsp;Alireza Zarasvandi,&nbsp;Samaneh Razi Jalali","doi":"10.1134/S0016702924030078","DOIUrl":"10.1134/S0016702924030078","url":null,"abstract":"<p>The Bam area is located north of the Kerman magmatic copper belt (KMCB) in SE Iran. It belongs to the Urumieh-Dothtar magmatic assemblage (UDMA) that hosts many large Cu-porphyry deposits such as Sarchemeh, Iju, Meiduk, Pakram, and Dalli. The area comprises volcanic and volcano-sedimentary rocks of the Eocene intruded by some sub-volcanic patches. Geochemical analyses show that the sub-volcanic rocks are calc-alkaline granodiorites formed on an active continental margin. The rare earth elements (REE) distribution patterns are differentiated (La_N/Yb_N = 4–31), having weak to moderate Eu negative anomalies (Eu/Eu* = 0.4–0.8) and flat heavy rare earth element (HREE) sections. The MgO, SiO₂, La, Yb, Sr, Sm, and Y contents of these rocks are consistent with adakite-like magmas formed by partial melting of thickened lower crust containing no garnet. Negative correlations of Al₂O₃, Y and Ba with SiO₂ and moderate to weak Eu negative anomalies, indicate the role of hornblende, K-feldspar, and plagioclase fractionation in the formation of these rocks. Geochemical features of the Bam sub-volcanic rocks are similar to those of the Cu-porphyry deposits from UDMA and Malmyzh deposit from eastern Russia, indicating fertility of these rocks for Cu mineralization that should be considered in the future explorations.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 3","pages":"300 - 313"},"PeriodicalIF":0.7,"publicationDate":"2024-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139518592","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":"Strontium and Neodymium Isotopic Signatures in Basalt Glasses of the Mid-Atlantic Ridge, 12°–31° N","authors":"A. R. Tskhovrebova,&nbsp;V. V. Shabykova,&nbsp;S. A. Silantyev,&nbsp;A. I. Buikin","doi":"10.1134/S0016702923120054","DOIUrl":"10.1134/S0016702923120054","url":null,"abstract":"<p>This paper presents the new geochemical isotope (Sr–Nd system, H₂O, Cl) data obtained for basalt glasses of the Mid-Atlantic Ridge (MAR) sampled from six areas of the MAR axial zone between 31° and 12° N. The data are consistent with the existing ideas about large-scale geochemical segmentation of the MAR. It is shown that samples from predominantly serpentinite segments have a narrower range of variations of strontium isotopic composition (⁸⁷Sr/⁸⁶Sr = 0.7027–0.7032) in comparison with samples collected from the areas where the crustal section is dominated by basalts (⁸⁷Sr/⁸⁶Sr = 0.7024–0.7041). The variation ranges of the neodymium isotopic composition in these two groups of samples are almost identical (εNd = +4.9 to +10.9 and +5.9 to +11.6 in serpentinite and basalt segments, respectively), although, in general, serpentinite segments have a slightly more enriched composition. The wide variations of the neodymium isotopic composition and increased contents of Cl, H₂O, and U, as well as increased K₂O/TiO₂ and La/Sm ratios, in samples from serpentinites can most probably be related to the participation of different geochemically heterogeneous sources in the magmatism of the MAR axial zone. The influence of enriched plume-type matter cannot be excluded in some segments. The isotopic composition of noble gases may shed light on the subject.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1241 - 1252"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714592","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":"Thermal and Thermochemical Study of Thaumasite","authors":"Yu. D. Gritsenko,&nbsp;M. F. Vigasina,&nbsp;L. V. Mel’chakova,&nbsp;L. P. Ogorodova,&nbsp;D. A. Ksenofontov,&nbsp;S. K. Dedushenko","doi":"10.1134/S0016702923110046","DOIUrl":"10.1134/S0016702923110046","url":null,"abstract":"<p>A sample of natural thaumasite Ca_3.0Si(OH)₆(CO₃)_0.9(SO₄)_1.1·12.3H₂O (N’Chwaning mine, Kalahari manganese ore field, South Africa) was studied by powder X-ray diffraction, infrared absorption and Raman spectroscopy, thermal analysis, and microcalorimetry. The process of thermal transformation of thaumasite was studied using the results of FTIR and Raman spectroscopy. The enthalpy of formation from elements Δ_f<i>H</i>⁰(298.15 K) = −8816 ± 30 kJ/mol was determined by high-temperature melt solution calorimetry. The value of the absolute entropy was estimated, and the enthalpy and Gibbs energy of formation of thaumasite of theoretical composition were calculated: 945.4 ± 1.8 J/(mol K), −8699 ± 30 kJ/mol, −7577 ± 30 kJ/mol, respectively.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1273 - 1282"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714589","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 Environments. I. Mean Concentrations","authors":"V. B. Naumov,&nbsp;V. A. Dorofeeva,&nbsp;A. V. Girnis","doi":"10.1134/S0016702923120042","DOIUrl":"10.1134/S0016702923120042","url":null,"abstract":"<p>Data from our original database, which includes more than 2 600 000 analyses for 75 elements of mineral-hosted melt inclusions and quench glasses in volcanic rocks, are generalized to calculate the mean concentrations of major, volatile, ore, and trace elements in magmatic melts from the following dominant geodynamic environments: (I) spreading zones of oceanic plates (mid-oceanic ridges), (II) environments affected by mantle plumes in oceanic plates (oceanic islands and lava plateaus), (III, IV) environments related to subduction processes (III is zones of arc magmatism on the oceanic crust, and IV is zones of magmatism in active continental margins in which magma-generating processes involve the continental crust), (V) environments of continental rifts and areas with continental hotspots, and (VI) environments of backarc spreading. A histogram of SiO₂ distribution in natural magmatic melts shows a bimodal distribution: one of the maxima falls onto SiO₂ concentrations of 50–52 wt % and the other onto 72–76 wt %. The most widely spread melts contain 62–66 wt % SiO₂. Mean temperatures and pressures are calculated for each of the environments. The normalized multielemental patterns presented for environments I through VI show the ratios of the mean concentrations of elements in magmatic melts of mafic, intermediate, and felsic composition to the concentrations in the primitive mantle. Mean ratios of incompatible, trace, and volatile components (H₂O/Ce, K₂O/Cl, Nb/U, Ba/Rb, Ce/Pb, etc.) are evaluated for the melts of each of the environments. The variations in these ratios are calculated, and it is demonstrated that the ratios of incompatible elements are mostly statistically significantly different in the different environments. The differences are particularly significant between the ratios of the most differently incompatible elements (e.g., Nb/Yb) and some ratios involving volatile components (e.g., K₂O/H₂O).</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1253 - 1272"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714418","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":"Atmospheric Pollution from a Storage of Tungsten–Molybdenum Ore Mining and Processing Wastes","authors":"A. M. Plyusnin,&nbsp;Yu. S. Voronina,&nbsp;A. V. Ukraintsev,&nbsp;M. K. Chernyavskii,&nbsp;E. G. Peryazeva,&nbsp;E. P. Chebykin","doi":"10.1134/S0016702923110095","DOIUrl":"10.1134/S0016702923110095","url":null,"abstract":"<p>Experimental studies of the surface atmosphere pollution with mining and processing wastes of tungsten–molybdenum ore were carried out using an equipment devised for collecting aerosols above the surface of sands. It has been established that toxic components formed during the decomposition of residual sulfide mineralization and products of interaction between acidic waters and rocks are transported with water vapor from the sands to the surface. The moisture condensed over the sands contains high concentrations of aluminum, fluorine, iron, silicon, manganese, zinc, and phosphorus. These elements form an atmospheric pollution halo over the technogenic sands and are further dispersed by air currents over neighboring areas. In winter, the snow cover is polluted over a vast territory due to wind dispersion of the aerosols. The halo of pollution extends over tens of square kilometers. A dependence was identified of qualitative and quantitative composition of the components polluting the snow cover on the storage time of the ore processing products. It is shown that some of the toxic elements pass into solution during snow melting from suspended solids, which are brought by wind from the territory where the soil cover is disturbed by mining.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1293 - 1307"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714409","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":"Environmental Geochemical Characteristics of Selenium in Northeast China","authors":"H. M. Dai,&nbsp;I. Savin,&nbsp;Y. H. Zhang,&nbsp;S. Liang,&nbsp;Y. J. Cui,&nbsp;C. Q. Chen,&nbsp;K. Liu,&nbsp;Y. H. Song","doi":"10.1134/S0016702923020106","DOIUrl":"10.1134/S0016702923020106","url":null,"abstract":"<p>Selenium is an important element for human health. Many studies have identified selenium deficiency in soil and water as an important factor in causing Keshan Disease (KD) in Northeast China. Previous studies have mainly focused on soil selenium content, staple food selenium content, and human selenium level, but there are few systematic studies on soil selenium’s existing forms and their migration from soil to crops and the human body. This paper focused on inferring the barrier factors in the migration of selenium from soil to crop and the human body and transformation of its compounds. It provides a reference basis for the etiological analysis, prevention, control, and elimination of KD. The study used 121 183 samples of topsoil (0−20 cm), 30 295 soil parent samples of selenium and other geochemical indices in northeast China, and crop seeds and human hair samples from the KD endemic area. The surface soil selenium was dominantly selenium-sufficient in Northeast China. However, the soil selenium levels were generally low. The average topsoil selenium in Northeast China was 0.20 mg/kg, significantly lower than the world’s average soil selenium content (0.4 mg/kg) and slightly lower than the Chinese average soil selenium content (0.24 mg/kg). Soil selenium mainly existed in strongly bounding by organic bound, with humic acid, and residue forms. The amount of selenium available to plants was sufficient in the selenium-sufficient and KD-endemic areas. However, the average selenium content of human hair was deficient, on average, with 0.16 mg/kg in KD endemic area. We assume that lower soil selenium content may be the basic factor influencing the biogeochemical deficiency of selenium in Northeast China. The sequestration of selenium by clay chemical constituents, such as iron and aluminum oxides and soil organic matter, especially in acidic soils, is another direct contributing factor to the low selenium content in biogeochemical food chain, which increases the risk of KD in the population.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 3","pages":"314 - 326"},"PeriodicalIF":0.7,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138563423","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":"Erratum to: Geochemistry (TE, REE, Oxygen) of Zircon from Leucogranites of the Belokurikhinsky Massif, Gorny Altai, as Indicator of Formation Conditions","authors":"E. V. Levashova,&nbsp;M. E. Mamykina,&nbsp;S. G. Skublov,&nbsp;O. L. Galankina,&nbsp;Q.-L. Li,&nbsp;X.-H. Li","doi":"10.1134/S0016702923210048","DOIUrl":"10.1134/S0016702923210048","url":null,"abstract":"","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 11","pages":"1220 - 1220"},"PeriodicalIF":0.8,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0016702923210048.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134795423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isotopic (δ13C, δ18O) Analysis of Small Amounts of Carbonate in Silicate Rocks by the Continuous Flow Isotope Ratio Mass Spectrometry Method","authors":"E. O. Dubinina,&nbsp;Y. N. Chizhova,&nbsp;S. A. Kossova","doi":"10.1134/S0016702923110034","DOIUrl":"10.1134/S0016702923110034","url":null,"abstract":"<p>An experimental study of the main factors affecting the accuracy of oxygen and carbon isotopic analysis in carbonates dispersed in silicate matrix is carried out. Artificial 1, 2, 5, and 10% mixtures of quartz with carbonates with different isotopic parameters (KH-2, Ko, MCA-8) were analyzed by continuous flow isotope ratio mass spectrometry (CF IRMS). It is established that, in addition to the influence of the instrumental nonlinearity, the results are affected by two factors: trace amounts of CO₂, constantly present in the system (the blank effect) and the presence of chemically neutral silicate particles (the matrix effect). The blank effect depends on the isotopic parameters of the sample and has very little influence on the estimated carbonate content in the rock. The matrix effect, on the contrary, strongly affects the estimated carbonate content, and produces the isotopic shift towards underestimated contents of heavy ¹³C and ¹⁸O isotopes. It is shown that this effect is related to the processes occurring near the CO₂–acid–quartz interface, which are accompanied by kinetic fractionation of carbon and oxygen isotopes. Both effects are dependent on the amount of silicate matrix in the system and most clearly manifested during analysis of carbonate-poor rocks. When the carbonate content in the rock is about 1–2%, deviations from the true δ¹³C and δ¹⁸O values can reach the first ppm, while carbonate content obtained by chromatographic peak calibration can be underestimated by 20–40%.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 11","pages":"1164 - 1176"},"PeriodicalIF":0.8,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0016702923110034.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}