Doklady Earth Sciences最新文献

{"title":"Sulfur Isotope Composition of Kuvaevite (Ir5Ni10S16) and Tolovkite (IrSbS): First Results","authors":"I. Yu. Badanina, V. V. Murzin, K. N. Malitch","doi":"10.1134/s1028334x24603274","DOIUrl":"https://doi.org/10.1134/s1028334x24603274","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of studying the sulfur isotope system in platinum-group minerals (PGM) are rare and generally limited to S-isotope data for Ru-Os sulfides from dunite-harzburgite massifs. To partially fill this gap, we for the first time characterized features of the S-isotopic composition of kuvaevite (Ir₅Ni₁₀S₁₆) and tolovkite (IrSbS) from the Verkh-Neivinsk dunite-harzburgite massif, a typical representative of the ophiolitic association at the Middle Urals. The study employed a number of analytical techniques, including scanning electron microscopy, electron microprobe analysis and a femtosecond laser ablation with a gas source isotope ratio mass spectrometry. The primary PGM assemblage is formed by osmium and iridium minerals, laurite, kuvaevite and Pt–Fe alloys, which are replaced by As-bearing laurite, irarsite, tolovkite and other PGM of secondary origin. Kuvaevite is characterized by a predominance of Ni over Fe, Cu, and Co (Ni/(Ni + Fe + Cu + Co from 0.56 to 0.58), as well as Ir over other platinum-group elements (PGE) (i.e., Ir/(Ir + Rh + Os + Ru + Pt + Pd) = 1.00); tolovkite is characterized by trace amounts of Pt (0.51–2.86 wt %), Rh (0.58–1.36 wt %), Ru (0.31–1.47 wt %), Ni (0.34–0.74 wt %), Cu (0.06–1.10 wt %), and As (0.06–1.44 wt %). Particularities of the isotopic composition of sulfur in kuvaevite (δ³⁴S from 0.9 to 2.1‰, mean δ³⁴S 1.5 ± 0.5‰, <i>n</i> = 4) are indicative of the mantle source with a chondritic isotope composition. The heavy sulfur isotope composition of tolovkite (δ³⁴S from 5.0 to 7.8‰; mean δ³⁴S 5.9 ± 0.9‰, <i>n</i> = 8) indicates the participation of sulfur of crustal origin (for example, isotopically heavy sulfur derived from host sedimentary rocks), being consistent with the secondary origin of the tolovkite. New data support the conclusion about contrasting sources of sulfur and a multistage evolution of PGE mineralization.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"8 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252204","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":"Spectroscopy of Noble Metal Minerals from the Vasilinovskoe Copper–Gold–Platinoid Ore Occurrence (Polar Urals, Russia)","authors":"R. I. Shaibekov, S. I. Isaenko, E. M. Tropnikov","doi":"10.1134/s1028334x24603390","DOIUrl":"https://doi.org/10.1134/s1028334x24603390","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Information about the spectra of noble metal minerals obtained by Raman spectroscopy, using the example of a new copper–gold–platinum ore occurrence in the Polar Urals, is presented. For the first time, spectra of temagamite and minerals of the intermediate merenskyite–moncheite series were obtained, and some of the previously detected minerals are refined and confirmed. The prerequisites for new mineral phases of the intermediate series are noted, difficulties in using the method and the need for further development of this area of research are indicated. It is shown that the use of Raman spectroscopy, in controversial cases, complements and often clarifies the data of microprobe studies.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"41 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189614","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":"Energy of Cyclones and Anticyclones during Their Development","authors":"M. G. Akperov, G. S. Golitsyn, V. A. Semenov","doi":"10.1134/s1028334x24603468","DOIUrl":"https://doi.org/10.1134/s1028334x24603468","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Using the statistical properties of the solution of the Fokker–Planck–Kolmogorov equation (FPK) for velocities and coordinates and using the vortex identification method, quantitative estimates of the distributions of various characteristics of cyclones and anticyclones (including lifetime, wind speed, size, characteristic forcing, and kinetic energy) depending on their intensity have been obtained. The calculations are based on ERA5 reanalysis data for the period 2010–2021. The vortex lifetimes estimated using the FPK correspond to the lifetimes obtained using the vortex identification method, and the theoretical distribution of cyclones by intensity practically coincides with those observed. The characteristics of vortices during their life cycle are also investigated. In general, all the characteristics of cyclones analyzed increase with their intensification. However, for intense anticyclones, the increase is not as pronounced as for cyclones.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"73 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189628","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 Rb–Sr Age of Authigenic Glauconite and U–Pb Age of Detrital Zircons from Riphean and Vendian Deposits of the Mezen Syneclise, East European Platform (Keltmen-1 Borehole)","authors":"T. S. Zaitseva, E. Yu. Golubkova, A. B. Kuznetsov, N. B. Kuznetsov, T. V. Romanyuk, E. G. Dovzhikova, O. K. Kaurova","doi":"10.1134/s1028334x24603419","DOIUrl":"https://doi.org/10.1134/s1028334x24603419","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The Rb–Sr age of glauconite and the U–Pb LA-ICP-MS age of detrital zircons from sandstones of the Riphean Okos Formation and the Vendian Ust-Pinega Formation were determined in the Keltmen-1 parametric borehole, drilled in the Vychegda trough of the Mezen syneclise in the northern part of European Russia. The model Rb–Sr age of glauconite (870–820 Ma) and the U–Pb age of the youngest detrital zircon (1005 ± 14 Ma) limit the time of accumulation of the Okos Formation to the first half of the Late Riphean, which is in good agreement with the biostratigraphic data available. The U–Pb age of the youngest detrital zircon from the lower part of the Ust-Pinega Formation suggests that accumulation of Late Vendian sandstones into the Mezen Basin began about 575 Ma. Thus, the duration of the stratigraphic hiatus between the Riphean and Vendian is estimated to be about 250–300 Ma. In the Late Riphean and Late Vendian, the Mezen basin was filled with terrigenous material of Archean–Late Proterozoic age (from 3.25 to 1.02 Ga), the sources of which were rocks of the Baltic Shield. In the lower part of the Ust-Pinega Formation, a population of detrital zircon of Vendian age (730–575 Ma) was discovered, a possible source of which could have been rocks of the Proto-Ural–Timan Orogen.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"23 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189635","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":"Airborne Gravimetry Measurements over Baikal","authors":"V. N. Koneshov, P. S. Mikhailov","doi":"10.1134/s1028334x2460347x","DOIUrl":"https://doi.org/10.1134/s1028334x2460347x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of the first high-precision airborne gravimetric route survey, which was conducted in 2023 along a transverse profile of Lake Baikal at a flight altitude of 5300 m, are presented. The use of an airborne gravimetric complex based on the AN-26BRL aircraft–laboratory is described. Directly over the lake, the largest negative measured anomaly of the gravity field was –180.8 mGal and the horizontal gradient of the field measurement was up to 9 and 5 mGal/km for the western and eastern shores of Lake Baikal, respectively. The internal convergence of anomaly values along the route profile for a complex of three gravimeters was 0.74 mGal. The estimations of the resolution and reliability of most topical current global models of the Earth’s gravity field (UGM-SGG-2, EGM2008, XGM2019, and Sandwell and Smith v32) based on satellite data are assessed for the Baikal rift basin. It is shown that the mean square deviations of the field along the entire profile between the values calculated from satellite models with a number of spherical harmonic coefficients of ≥2190 and the airborne gravimetric observations are 9.5‒17.9 mGal, whereas the maximum deviations at individual points of the route are 40–80 mGal. The comparison with data on the marine gravimetric survey on a scale of 1 : 500 000 is carried out using airborne profile data. Due to the highly detailed data along the airborne gravimetry profile, it is established that the factual value of the main negative anomaly on the air profile is higher than that accepted for the analysis and complex interpretation of geophysical data in the area of Lake Baikal.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"9 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189631","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":"Calculation of Slope Safety Factor Based on Deep Learning Response Surface","authors":"Liujie Zhang, Ming Li","doi":"10.1134/s1028334x24601792","DOIUrl":"https://doi.org/10.1134/s1028334x24601792","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The slope safety factor is a crucial indicator for assessing slope stability. However, the current methods for calculating safety factors are predominantly based on the search of limit equilibrium theory and the iteration of finite element methods, leading to overly intricate computational procedures. Considering classical mechanics theory and the definition of slope safety factors, there inevitably exists a certain functional relationship between various slope parameters and their safety factors. Thus, we propose an approach utilizing response surface surrogate functions to express this relationship.We studied two types of slopes: soil slopes and rock slopes. For soil slopes, assumed to be single-layer saturated clay, we considered five parameters: soil density, cohesion, friction angle, slope height, and slope angle. For rock slopes, we considered six parameters: rock density, uniaxial compressive strength of the rock, GSI, mi, slope height, and slope angle.we introduce a data sampling technique based on genetic algorithms to enhance the quality of training data. This approach reduces the uncertainty in fitting outcomes while minimizing the volume of sample data, while still meeting precision requirements and generalizability.To address the demands of this study, we establish a convolutional neural network to approximate the response surface. A comparison is made with response surfaces approximated using FCNN and polynomial methods, revealing superior performance of the convolutional neural network. Following training, the surrogate function derived enables rapid and accurate computation of the slope safety factor.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"30 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189613","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":"A Pilot National Network for Monitoring Soil Respiration in Russia: First Results and Prospects of Development","authors":"I. N. Kurganova, D. V. Karelin, V. M. Kotlyakov, A. S. Prokushkin, D. G. Zamolodchikov, A. V. Ivanov, D. V. Ilyasov, D. A. Khoroshaev, V. O. Lopes de Gerenyu, A. A. Bobrik, S. V. Bryanin, O. Yu. Goncharova, V. V. Ershov, D. G. Ivanov, S. Yu. Zorina, V. V. Kaganov, E. A. Kapitsa, G. N. Koptsik, M. A. Kuznetsov, A. S. Kumanyaev, A. V. Kuprin, A. V. Mamai, A. I. Matvienko, A. V. Makhnykina, A. S. Mostovaya, E. V. Moshkina, S. Yu. Mothenov, N. S. Ryabov, D. V. Sapronov, N. V. Sidenko, L. G. Sokolova, A. S. Sorokin, G. G. Suvorov, O. E. Sukhoveeva, A. S. Chumbaev, N. Yu. Shmakova","doi":"10.1134/s1028334x24603377","DOIUrl":"https://doi.org/10.1134/s1028334x24603377","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Soil respiration (SR) is one of the largest fluxes in the global carbon cycle, exceeding anthropogenic CO₂ emission by more than an order of magnitude. Estimation of the heterotrophic component of SR is necessary to assess the carbon balance on the ecosystem and on the regional, national, and global scales. Within the framework of the most important national innovation project “Development of a System of Ground-based and Remote Monitoring of Carbon Pools and Greenhouse Gas Fluxes on the Territory of the Russian Federation,” the first Russian national network is organized to monitor CO₂ emission from soils and other linked parameters. The SR values and the relationship with the temperature of the upper 5- to 10-cm layer of soil (TS) are analyzed for the first time on the territory of Russia based on methodologically identical field measurements conducted simultaneously in the summer period (June–August 2023) at 75 monitoring sites in the different ecosystems in the main Russian bioclimatic zones from the tundra to the semidesert. The positive effect of soil temperature on the mean summer SR rate and the maximum monthly SR values is observed in the interval of mean TS from 10 to 20°C. Among the ecosystems studied, the lowest SR values are recorded in tundra and bog ecosystems, while the highest values are in the forest–steppe. Amongst the forest ecosystems, the lowest SR rates are characteristic of larch forests, while the highest SR values are observed in broadleaved forests of the forest–steppe zone. To clarify the regularities obtained, it is necessary to expand studies in all bioclimatic zones, but mainly in agrocenoses, tundra, and steppe ecosystems.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"23 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189625","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":"Assimilation of Carbonates by Mafic Magma: Fassaite Gabbro of the Olkhon Terrane (Western Baikal Region)","authors":"E. V. Sklyarov, A. V. Lavrenchuk, D. V. Semenova","doi":"10.1134/s1028334x24603055","DOIUrl":"https://doi.org/10.1134/s1028334x24603055","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Specific gabbro with the main rock-forming mineral of fassaite—alumina-rich (up to 12 wt % Al₂O₃) calcium pyroxene, typical of high-temperature metasomatic rocks, are characterized. In terms of the geochemical characteristics, the fassaite gabbros are close to the subalkaline monzogabbros of the Ust’-Krestovsky complex, which are widely distributed within the Krestovsky subterrane of the Olkhon terrane (Western Baikal region). At the same time, they differ sharply from the latter in having a higher content of CaO and MgO and a lower content of SiO₂ and Al₂O₃. Fassaite gabbro composes several small bodies framed the Ust’-Krestovsky monzogabbro massif, without contacting the latter. A model of the formation of fassaite gabbro due to the assimilation of carbonate (crustal carbonate melts) by subalkaline mafic magma is proposed.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"73 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189612","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 Geoecological Phenomenon Due to the Absence of Conditions and Regulation of Water of the Don River","authors":"G. G. Matishov, K. S. Grigorenko","doi":"10.1134/s1028334x24603171","DOIUrl":"https://doi.org/10.1134/s1028334x24603171","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Over the seventy-year period of the Don River valley flood control with the absence of a water climatic cycle, irreversible geomorphological and biogeocenotic transformations occurred in the drainage basin. As a result of persistent avalanche sedimentation, the Don delta and the Taganrog Bay seaside became shallow. During strong east winds, the seabed near the city of Taganrog and the settlements of Port-Katon and Zaimo-Obryv is dried out over a distance of 5–10 km or more. The unique phenomenon of carp and sazan activity and accumulation in the Don River delta was noted in winter of 2023–2024. Clearly abnormal mass accumulations of valuable commercial species and their early maturation could be related to a range of factors provoked by the increased water discharge from the Tsimlyansk Reservoir. The water flow with fish along the Krivoe and Svinoe delta arms, at an extreme water negative setup, came up against a sandbar, which reflects the Don River shallowing after 1952.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"11 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189624","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":"New Research Results on Geochemistry and Zircon U–Pb Geochronology of Ankroet Granite in Dalat Zone and Geological Significance","authors":"Tran Van Xuan, Pham Minh, Pham Trung Hieu, Nguyen Tuan","doi":"10.1134/s1028334x24602591","DOIUrl":"https://doi.org/10.1134/s1028334x24602591","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Ankroet granite from the Dalat zone (DZ), Vietnam, is commonly the main petrographic composition of granite and biotite granite, coinciding with the Ankroet complex. The primary rock-forming minerals of the Ankroet granite include plagioclase (30–35%), quartz (30–35%), K-feldspar (25–30%), and biotite (5–7%). Geochemically, they are metaluminous with an average A/CNK value of 0.95–1.04, high SiO₂ (73.68–74.14), and low Na₂O/K₂O &lt; 1. Petrographical and geochemical characteristics of Ankroet granites are classified as A-type granite generated from post-orogenic magmas. Zircons selected from these rocks are characterized by prismatic shape, oscillatory zoning, no luminescent rim, and a high ratio Th/U (0.75–1.78) that are indications of the magmatic origin. We report the first LA-ICP-MS ²⁰⁶Pb/²³⁸U zircon ages of 87.9 Ma for the Ankroet granite in the DZ in southern Vietnam. This age value is temporally consistent with Late Cretaceous magmatism previously reported in the DZ. Together with other Late Mesozoic magmatic complexes along the DZ, the Ankroet granites are a representative of magmatism linked to post-orogenic magmas beneath the Indochina block during the Late Cretaceous.</p>","PeriodicalId":11352,"journal":{"name":"Doklady Earth Sciences","volume":"30 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189626","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}