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Geochemistry and Fertility Assessment of Sub-Volcanic Rocks from the Bam Area, North of the Kerman Magmatic Copper Belt, SE Iran 伊朗东南部克尔曼岩浆铜矿带北部巴姆地区火山下岩石的地球化学和肥力评估
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2024-01-21 DOI: 10.1134/S0016702924030078
Mirmohammad Miri, Alireza Zarasvandi, Samaneh Razi Jalali
{"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<sub>N</sub>/Yb<sub>N</sub> = 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, SiO<sub>2</sub>, 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 Al<sub>2</sub>O<sub>3</sub>, Y and Ba with SiO<sub>2</sub> 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}
引用次数: 0
Geochemical Characteristics of the Upper Permian Shales in the Central Nanpanjiang Basin: Implications for Paleoenvironment Conditions 南盘江盆地中部上二叠统页岩的地球化学特征:古环境条件的影响
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2024-01-21 DOI: 10.1134/S001670292403008X
Lijun Shen, Yifan Gu, Zhihong Wei, Dongfeng Hu, Ruobing Liu, Yuqiang Jiang, Yonghong Fu
{"title":"Geochemical Characteristics of the Upper Permian Shales in the Central Nanpanjiang Basin: Implications for Paleoenvironment Conditions","authors":"Lijun Shen,&nbsp;Yifan Gu,&nbsp;Zhihong Wei,&nbsp;Dongfeng Hu,&nbsp;Ruobing Liu,&nbsp;Yuqiang Jiang,&nbsp;Yonghong Fu","doi":"10.1134/S001670292403008X","DOIUrl":"10.1134/S001670292403008X","url":null,"abstract":"<p>Sedimentary environment can be restored qualitatively or semi-qualitatively by using elements or element combinations that are sensitive to paleoenvironment conditions. By measuring the major elements, trace elements and rare earth elements of 23 shale samples collected from coring wells in the Central Nanpanjiang Basin, we discussed the paleoenvironment conditions, including paleo-water depth, redox conditions, paleoclimate and provenance. La and Co contents indicate that the paleo-water depth in the Central Nanpanjiang Basin gradually deepened during the Late Permian. The ratios of U/Th, U<sub>au</sub>, V/Cr, Ni/Co and V/Sc suggest that the Central Nanpanjiang Basin was in an oxic condition in the Late Permian, which was stable during the Permian Longtan and Dalong depositional periods. C-value (Climate index value) and binary diagrams of Sr/Cu and Ga/Rb show that the Central Nanpanjiang Basin was characterized by a warm and arid climate during the depositional of the Permian Longtan Formation, a warm and humid climate in the lower part of the Dalong Formation, and a warm and arid climate again in the upper part of the Dalong Formation. The chemical index of alteration (CIA), plagioclase index of alteration (PIA), index of chemical variability (ICV), and Th/U and K/Rb values can indicate the geological tectonic settings of source regions. From the Longtan period to the Dalong period, the small CIA amplitude and relatively stable ICV indicate that chemical weathering in the source area was constantly slighty weak. However, Th/U increased significantly but PIA increased slightly in the lower Dalong Formation, indicating an obvious climate change in the early deposition of the Dalong Formation. In addition, the geochemical discrimination calculation and plots show that the provenance of the studied shales was related to felsic volcanic rocks and the tectonic settings of the Upper Permian shale source areas in the Central Nanpanjiang Basin were mainly oceanic island arc and continental arc.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 4","pages":"403 - 418"},"PeriodicalIF":0.7,"publicationDate":"2024-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139518424","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}
引用次数: 0
Organic Matter Source Traced by n-Alkane Records Derived from Sediments of Barkol Lake in Eastern Xinjiang (NW China) and Its Response to Moisture Variability in the Past 8800 Years 新疆东部(中国西北部)巴尔喀湖沉积物正烷烃记录所显示的有机质来源及其对过去 8800 年湿度变化的响应
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2024-01-21 DOI: 10.1134/S0016702924030091
Zhi Wang, Wei Zhong, Xiaojun Wang, Yingyi Du, Tianhang Li, Jibin Xue, Mingying Quan
{"title":"Organic Matter Source Traced by n-Alkane Records Derived from Sediments of Barkol Lake in Eastern Xinjiang (NW China) and Its Response to Moisture Variability in the Past 8800 Years","authors":"Zhi Wang,&nbsp;Wei Zhong,&nbsp;Xiaojun Wang,&nbsp;Yingyi Du,&nbsp;Tianhang Li,&nbsp;Jibin Xue,&nbsp;Mingying Quan","doi":"10.1134/S0016702924030091","DOIUrl":"10.1134/S0016702924030091","url":null,"abstract":"<p>Previous multi-proxy records have revealed the advantages of well-preserved and long-scale geological archives from the lake sediments of Barkol Lake, which is located at northeast Xinjiang in northwest China. However, the exact organic matter (OM) sources in the sediments and their response to climatic variability still remain unclear in this area. In this study, we present an 8.8 kyr <i>n</i>-alkane record extracted from the sediments in Barkol Lake to explore the OM sources and the relationship between <i>n</i>-alkanes and climatic changes. The results indicate that the <i>n</i>-alkane composition was dominated by long-chain <i>n</i>-alkanes(C<sub>27</sub>–C<sub>31</sub>), implying a dominant origination of OM from the terrestrial higher plants and emergent aquatic plants. The <i>n</i>-alkane data further revealed that changes in OM sources were related to the surface erosion-transportation-deposition processes controlled by climatic changes. Lake level changes, which are also regulated by climate conditions, played an important role in impacting OM accumulation. Relatively wetter conditions would result in a rising lake level that favored more aquatic OM and less terrestrial OM input, and <i>vice versa</i>. The regional climate patterns have been generally dominated by alternations of cold-wet and warm-dry episodes over the past ~8.8 kyr. We preliminarily concluded the dynamic changes of OM input and the hydrological changes in Barkol Lake was mainly controlled by SSTs in the North Atlantic region and melting water supply modulated by Eurasian ice sheet.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"62 4","pages":"419 - 433"},"PeriodicalIF":0.7,"publicationDate":"2024-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139518519","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}
引用次数: 0
Sr–Nd Isotopic Evidence of a Heterogeneous Magmatic Source of Alkaline–Carbonatite Rocks of the Odikhincha Alkaline–Carbonatite Massif (Maimecha-Kotui Province, Siberia) 奥迪金查碱性碳酸盐岩块(西伯利亚梅查-科推省)碱性碳酸盐岩异质岩浆源的钍钕同位素证据
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923120030
Y. A. Kostitsyn, A. R. Tskhovrebova, I. T. Rass, M. O. Anosova
{"title":"Sr–Nd Isotopic Evidence of a Heterogeneous Magmatic Source of Alkaline–Carbonatite Rocks of the Odikhincha Alkaline–Carbonatite Massif (Maimecha-Kotui Province, Siberia)","authors":"Y. A. Kostitsyn,&nbsp;A. R. Tskhovrebova,&nbsp;I. T. Rass,&nbsp;M. O. Anosova","doi":"10.1134/S0016702923120030","DOIUrl":"10.1134/S0016702923120030","url":null,"abstract":"<p>This study focuses on the igneous rocks composing the Odikhincha massif. The massif is typical ring alkaline–ultrabasic massif with carbonatites, second largest in the Maimecha-Kotui province. The Sr-Nd isotopic values of the traps of the Arydzhang Formation and the host dolomites were also determined for comparison. The Rb–Sr isotope system of phlogopite and calcite from the Od-16-19 carbonatite of the Odikhincha massif is disturbed; the obtained age on the mineral isochrone (245 ± 3 Ma) is close to the time of formation of the Siberian traps and rocks of the ultrabasic–alkaline Maimecha-Kotui complex, but the large scatter of analytical points (MSWD = 22) does not allow this date to be considered as reliable. The disturbance of the isotope system is probably related to the fact that the strontium isotope ratio in the fluid was not constant during autometasomatic phlogopitization of carbonatite. The U–Pb isotopic system of titanite and perovskite from the same carbonatite sample Od-16-19 also appeared to be disturbed, since data points formed discordia. The U–Pb age obtained for titanite and perovskite are 244 ± 5 Ma (MSWD = 1.8) and 247 ± 18 Ma (MSWD = 4), respectively. Apparently, the age values provided by the two isotopic systems (245 ± 3 Ma by Rb–Sr and 247 ± 18 and 244 ± 5 Ma by U–Pb) are consistent with each other and reflect the time of metasomatic processes, i.e., phlogopitization and iolitization. Rb–Sr and Sm–Nd isotope data for ultrabasic–alkaline intrusive rocks with carbonatites of the Odikhincha massif and volcanics of the Arydzhang Formation indicate an enriched, relative to the composition of the convecting mantle, isotopically heterogeneous source of their parent melts. This source could be a combination of ultrabasic mantle rocks and rocks of basic composition (basites). The latter played the role of an enriched component. No signs of contamination of the melts with the host sedimentary rocks in situ were found, however, variations of Sr and Nd isotopic ratios in the rocks of the Odikhincha massif may indicate that during the introduction of deep magmas their interaction and substance exchange with the surrounding rocks of the lithosphere continued up to complete solidification of the melts, as indicated by the nature of local isotopic heterogeneity within the Odikhincha intrusion.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1221 - 1240"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0016702923120030.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714598","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}
引用次数: 0
Strontium and Neodymium Isotopic Signatures in Basalt Glasses of the Mid-Atlantic Ridge, 12°–31° N 北纬 12°-31° 大西洋中脊玄武岩玻璃中的锶和钕同位素特征
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923120054
A. R. Tskhovrebova, V. V. Shabykova, S. A. Silantyev, A. I. Buikin
{"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, H<sub>2</sub>O, 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 (<sup>87</sup>Sr/<sup>86</sup>Sr = 0.7027–0.7032) in comparison with samples collected from the areas where the crustal section is dominated by basalts (<sup>87</sup>Sr/<sup>86</sup>Sr = 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, H<sub>2</sub>O, and U, as well as increased K<sub>2</sub>O/TiO<sub>2</sub> 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}
引用次数: 0
Thermal and Thermochemical Study of Thaumasite 辉绿岩的热和热化学研究
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923110046
Yu. D. Gritsenko, M. F. Vigasina, L. V. Mel’chakova, L. P. Ogorodova, D. A. Ksenofontov, S. K. Dedushenko
{"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<sub>3.0</sub>Si(OH)<sub>6</sub>(CO<sub>3</sub>)<sub>0.9</sub>(SO<sub>4</sub>)<sub>1.1</sub>·12.3H<sub>2</sub>O (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<sub>f</sub><i>H</i><sup>0</sup>(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}
引用次数: 0
Upper Riphean and Lower Paleozoic Quartzite Sandstones of the Circumpolar Urals: Geochemical Characteristics, Source Areas, and Conditions of Formation 北极圈乌拉尔地区的上更新统和下古生代石英岩砂岩:地球化学特征、产地和形成条件
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923110083
N. Yu. Nikulova
{"title":"Upper Riphean and Lower Paleozoic Quartzite Sandstones of the Circumpolar Urals: Geochemical Characteristics, Source Areas, and Conditions of Formation","authors":"N. Yu. Nikulova","doi":"10.1134/S0016702923110083","DOIUrl":"10.1134/S0016702923110083","url":null,"abstract":"<p><b>Abstract</b>—The results of study and comparison of geochemical characteristics of quartzite sandstones of the Upper Riphean Khobeyu and Lower Paleozoic Obeiz formations of the Circumpolar Urals are presented. It has been established that the composition of quartzite sandstone of both formations was formed mainly from recycled material of ancient metaterrigenous rocks, with the participation of destruction products of igneous rocks of felsic (Obeiz Formation) and basic (Khobeyu Formation) composition and weathering crust material. The accumulation of the Lower Paleozoic psammites was accompanied by a gradual change of clastic sources, with increasing contribution of granitoid clastics.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1283 - 1292"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714415","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}
引用次数: 0
Ecological and Geochemical Assessment of Snow Cover in the Area Affected by the Apatite–Nepheline Production of the Kola Peninsula 受科拉半岛霞石-霓虹灯生产影响地区积雪的生态和地球化学评估
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923120029
V. A. Dauvalter, S. S. Sandimirov, D. B. Denisov, M. V. Dauvalter, Z. I. Slukovskii
{"title":"Ecological and Geochemical Assessment of Snow Cover in the Area Affected by the Apatite–Nepheline Production of the Kola Peninsula","authors":"V. A. Dauvalter,&nbsp;S. S. Sandimirov,&nbsp;D. B. Denisov,&nbsp;M. V. Dauvalter,&nbsp;Z. I. Slukovskii","doi":"10.1134/S0016702923120029","DOIUrl":"10.1134/S0016702923120029","url":null,"abstract":"<p><b>Abstract</b>—The chemical composition of the snow cover in the area of industrial development of the apatite–nepheline deposit is analyzed to estimate the ecological and geochemical environmental impact of the mining enterprise. It has been established that the snow of the studied area of the Khibiny is enriched in Cl<sup>–</sup> and Na<sup>+</sup> ions (on average 38 and 41 µeq/L), and relations between basic ions (Cl<sup>–</sup> &gt; <span>({text{SO}}_{4}^{{2 - }})</span> &gt; <span>({text{HCO}}_{3}^{ - })</span> and Na<sup>+</sup>&gt; Ca<sup>2+</sup>&gt; K<sup>+</sup> = Mg<sup>2+</sup>) and mineralization value (from 1.7 to 6.4 mg/L) are typical for precipitates in the coastal regions of the northern European Russia. The average content of total nitrogen and phosphorus in the snow of the impact zone is 495 and 26 μg/L, respectively, which is 3 and 5 times higher than in the background zone. This is explained by their influx into the atmosphere with dust emissions from the mining enterprise. The content of organic matter (COD<sub>Mn</sub> and TOC 5.5 and 5.8 mg/L) in the snow of the impact zone is about two times higher than in the snow of the background zone and in the water of the Khibiny water bodies. Probably, the elevated content of organic matter in the snow is associated with the supply of organic substances-reagents from the tailing dump, which are used to obtain apatite concentrate, as well as the intensive growth of unicellular green algae <i>Chlamydomonas nivalis</i> (Bauer) Wille under conditions of an increased content of nutrients and long daylight hours. The concentrations of a number of heavy metals (Zn, Mn, Cu, Cr, Pb, Cd) in the snow of the impact zone exceed their contents in the water of water body of the impact zone (13.4, 5.4, 3.8, 0.8, 0.65, 0.035 μg/L, respectively). These metals enter the snow as a part of dust emissions from the mine, and as polluted air masses from the industrial regions of Eurasia.</p>","PeriodicalId":12781,"journal":{"name":"Geochemistry International","volume":"61 12","pages":"1308 - 1322"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714535","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}
引用次数: 0
Major, Volatile, Ore, and Trace Elements in Magmatic Melts in the Earth’s Dominant Geodynamic Environments. I. Mean Concentrations 地球主要地球动力环境中岩浆熔体中的主要元素、挥发性元素、矿石元素和微量元素。I. 平均浓度
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923120042
V. B. Naumov, V. A. Dorofeeva, A. V. Girnis
{"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 SiO<sub>2</sub> distribution in natural magmatic melts shows a bimodal distribution: one of the maxima falls onto SiO<sub>2</sub> concentrations of 50–52 wt % and the other onto 72–76 wt %. The most widely spread melts contain 62–66 wt % SiO<sub>2</sub>. 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 (H<sub>2</sub>O/Ce, K<sub>2</sub>O/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., K<sub>2</sub>O/H<sub>2</sub>O).</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}
引用次数: 0
Atmospheric Pollution from a Storage of Tungsten–Molybdenum Ore Mining and Processing Wastes 钨钼矿开采和加工废料贮存产生的大气污染
IF 0.7 4区 地球科学
Geochemistry International Pub Date : 2023-12-18 DOI: 10.1134/S0016702923110095
A. M. Plyusnin, Yu. S. Voronina, A. V. Ukraintsev, M. K. Chernyavskii, E. G. Peryazeva, E. P. Chebykin
{"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}
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