I. V. Chernyshev's research while affiliated with Russian Academy of Sciences and other places

Publications (158)

Article
The U-Pb isotope system and uranium isotope composition (235U/238U and 234U/238U) were studied in a number of samples from the vertical section of the uranium ore body at the Vershinnoe sandstone-type deposit, Vitim uranium ore district, Russia. These parameters were determined to broadly vary. Deviations of the 234U/238U ratio from the equilibrium...
Article
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The Bodaibo District (the Irkutsk Region of Russia) is a world-class gold-mining subprovince comprising a total of 13 large-and medium-scale black-shale-hosted orogenic gold deposits known as the Sukhoi Log-style gold deposits (Ivanov, 2014). The gold mineralization of the Sukhoi Log-style deposits is represented by early veinlet-disseminated sulfi...
Article
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To assess the nature of the post-ore behaviour of uranium in the Namaru deposit (Khiagda ore field), U–Pb isotope systems and the isotopic composition of uranium ( ²³⁴ U/ ²³⁸ U and ²³⁸ U/ ²³⁵ U) were studied. The studied samples represent different ore zones of the deposit and were collected along cross-sections both vertically and horizontally. Wi...
Article
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An isotope-geochronological study for a number of young volcanic manifestations in the eastern part of Balkaria (North Caucasus, Russia) referred by previous researchers to the Neogene-Quaternary stage of evolution of the Greater Caucasus was carried out. The obtained results of K–Ar dating have proved for the first time that volcanic activity with...
Article
Numerous orogenic gold deposits of different age, scale, and mineralization type are located within Northern Transbaikalia. Among them, there is a large group of Early Permian deposits, whose sources and relationships with Late Paleozoic magmatism remain debatable. These issues were solved by the example of the middle-scale (~24 t, Au) Irokinda dep...
Article
South Sikhote-Alin metallogenic subprovince (SSAP) is located in the southern part of the Sikhote-Alin orogenic belt. It encompasses more than one hundred well-known deposits and occurrences of boron, tin, lead, and zinc. These deposits have been genetically related to the Late Cretaceous and Paleocene granitoid magmatism. Pb isotope composition wa...
Article
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The results of isotope-geochronological study of Quaternary mafic volcanism in the Kapan neovolcanic center (Southern Armenia) are discussed. The rocks studied are represented by alkaline basaltoids with haüyne as the main foid (ordanchites and haüyne basanites), which are unique for the Caucasian Region. As is evidenced from the K-Ar age results,...
Article
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The results of petrological-geochemical and isotope-geochemical studies of the Late Pleistocene-Holocene lavas of the Kazbek neovolcanic center, one of the largest centers of youngest magmatism in the Greater Caucasus, are presented. It has been established that the volcanic rocks of the Kazbek center form a continuous compositional series basaltic...
Article
The isotopic composition of uranium is a new geochemical indicator that facilitates reconstruction of the redox conditions of geological processes. In this paper the results of study of the ²³⁸U/²³⁵U isotope ratio in the Neoproterozoic metasedimentary rocks of the Baikal–Patom fold belt (Northern Transbaikalia) were obtained using the MC-ICP-MS met...
Article
The trend fractionation of the ²³⁸U and ²³⁵U isotopes and the extent of this process at the oxidative weathering of uranium minerals were evaluated by studying the variations in the U isotope composition of rocks, minerals, and fracture waters sampled in the quarry of the broadly known Tulukuevskoe uranium deposit in the Streltsovskoe ore field, ea...
Article
This article is devoted to a study of variations in the U isotopic composition (238U/235U) in the section of clas- tic-carbonate Ediacaran sediments exposed along the Chaya River in the southern part of Central Siberia (Russia). Measurements of 238U/235U in the rocks were performed using a high-precision (±0.07%o, 2SD) MC-ICP- MS with a 233U-236U d...
Article
Full-text available
The isotopic composition of uranium is a new geochemical indicator that facilitates reconstruction of the redox conditions of geological processes. In this paper the results of study of the 238U/235U isotope ratio in the Neoproterozoic metasedimentary rocks of the Baikal–Patom fold belt (Northern Transbaikalia) were obtained using the MC-ICP-MS met...
Article
The paper describes the high-precision U-isotope analysis of rocks. The analysis is based on multicollector inductively coupled plasma mass spectrometry (MC−ICP−MS) and includes, as an essential part, the three-step ion-exchange chromatography separation of uranium from chemically complex solutions. In the analysis, the ²³⁵U and ²³⁸U mass-bias of t...
Article
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This paper presents the results from an isotope-geochronological and geochemical-petrological study of young volcanic rocks sampled in central Armenia, which were formed during the first stage of the Late Cenozoic magmatism in the Lesser Caucasus at the Miocene/Pliocene boundary. We have found the boundary of the area where the Miocene to Pliocene...
Article
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The paper considers the results of high-precision Pb–Pb isotopic analysis of 120 galena samples from 27 Au and Ag deposits of the South Verkhoyansk Synclinorium (SVS) including large Nezhdaninsky deposit (628.8 t Au). The Pb isotopic composition is analyzed on a MC-ICP-MS NEPTUNE mass-spectrometer from solutions with an error of no more than ±0.02%...
Article
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This paper reports the results of a detailed isotopic (Sm–Nd, Pb–Pb, and δ³⁴S) and geochemical studies of Neoproterozoic metasedimentary rocks from the Patom and Bodaibo domains of the Baikal–Patom belt (northern Transbaikalia). It was shown that the metasedimentary rocks of these domains are strongly variable in their geochemical and isotope geoch...
Data
Supplement material to V. A. Lebedev, A. V. Parfenov, G. T. Vashakidze, Q. A. Gabarashvili, I. V. Chernyshev, and M. G. Togonidze "Chronology of Magmatic Activity and Petrologic–Mineralogical Characteristics of Lavas of Kazbek Quaternary Volcano, Greater Caucasus", Petrology, 2018, Vol. 26, No. 1, pp. 1–28.
Data
Supplement material to V. A. Lebedev, A. V. Parfenov, G. T. Vashakidze, Q. A. Gabarashvili, I. V. Chernyshev, and M. G. Togonidze "Chronology of Magmatic Activity and Petrologic–Mineralogical Characteristics of Lavas of Kazbek Quaternary Volcano, Greater Caucasus", Petrology, 2018, Vol. 26, No. 1, pp. 1–28.
Data
Supplement material to V. A. Lebedev, A. V. Parfenov, G. T. Vashakidze, Q. A. Gabarashvili, I. V. Chernyshev, and M. G. Togonidze "Chronology of Magmatic Activity and Petrologic–Mineralogical Characteristics of Lavas of Kazbek Quaternary Volcano, Greater Caucasus", Petrology, 2018, Vol. 26, No. 1, pp. 1–28.
Article
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The paper presents detailed isotope-geochronological, geological, and petrologic-mineralogical data on lavas of one of the greatest Quaternary magmatic area in the Greater Caucasus, the Kazbek neovolcanic center, including polygenetic Kazbek stratovolcano and a number of subordinate volcanic cones in its vicinities. The research was conducted based...
Chapter
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Коллективная монография в иллюстрированной форме отражает результаты работ наших ученых, принимавших участие в выполнении проектов программы Президиума Российской академии наук «Природные катастрофы и адаптационные процессы в условиях изменяющегося климата и развития атомной энергетики».
Article
The paper reports the results of Pb isotope study of several gold deposits of the Russia’s largest metallogenic province of Northern Transbaikalia. Potential sources of the ore material are considered by the example of new and previously published Pb–Pb data on nine deposits and occurrences of different scales. The comparison of Pb–Pb isotope-geoch...
Article
The enrichment of lead isotopic composition of nonuranium minerals, in the first place galena in ²⁰⁶Pb and ²⁰⁷Pb, as compared to common lead is a remarkable feature of uranium deposits. The study of such lead isotopic composition anomalous in ²⁰⁶Pb and ²⁰⁷Pb in uranium minerals provides an opportunity for not only identification of superimposed pro...
Article
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The paper presents new geochronological and isotopic geochemical data on gold mineralization of the Kedrovsky deposit. The deposit is located in the northeastern part of the Transbaikal metallogenic province, Russia’s largest one. The Early Permian age (273 ± 4 Ma) of mineralization based on the results of Rb–Sr study of wallrock metasomatic rocks...
Article
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First systematic data on the variations of εNd(T) in the Neoproterozoic sedimentary sequence of the Baikal–Patom fold belt (Northern Transbaikalia) are reported. The range of obtained εNd(T) is–19.4…–2.0. It was established that the rocks of the Ballaganach and most part of the Dal’nyaya Taiga groups are characterized by εNd(T) from–19.4 to–16.3. U...
Article
The possibility of using hydrothermal fluorite as an Sm–Nd geochronometer is based on the results of an REE pattern study of this mineral (Chernyshev et al., 1986). As a result of REE fractionation, in many cases, the Sm/Nd ratio achieves a multifold increase compared with its level in terrestrial rocks, and the radiogenic shift of the ¹⁴³Nd/¹⁴⁴Nd...
Article
The variations in ²³⁸U/²³⁵U values accompanying mobilization of U by fracture waters from uranium-bearing rocks, in which U occurs as a fine impregnation of oxides and silicates, were studied by the high-precision (±0.07‰) MC–ICP–MS method. Transition of U into the aqueous phase in the oxidized state U(VI) is accompanied by its isotope fractionatio...
Article
The uneven character of the distribution of 18O/16O and 234U/238U values was established in the vertical cross section of the productive sequence of the Dybryn uranium deposit (Vitim uranium-ore region, Buryatia). Both a deficiency and an excess of 234U in relation to the equilibrium 234U/238U ratio in the vertical sequence may provide evidence for...
Article
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This work presents the first results of geochronological study of metasomatic rocks accompanying gold-bearing quartz veins of the Uryakh ore field (UOF). Based on the Rb-Sr and 39Ar-40Ar geochronological data, it is shown that hydrothermal metasomatic processes in the ore field occurred about 280 Ma ago (Early Permian) and they are correlated with...
Data
Multi-layer geological map of the Elbrus neovolcanic center (Greater Caucasus). Scale 1/100000. Compiled by V.A. Lebedev (IGEM RAS) ©. File is in PSD (Photoshop) format. Layers: topography, hydrology and glaciers (snow line at September, 2010), infrastructure, geological borders, color fields. Reference should be given as: Lebedev V.A. Geological M...
Data
Multi-layer geological map of Pliocene Dzhimara massif of granodiorites and quartz diorites (Greater Caucasus, Russian-Georgian state border), located in the vicinity of Late Quaternary Kazbek Volcano. Scale 1/25000. Compiled by V.A. Lebedev (IGEM RAS) ©. File is in PSD (Photoshop) format. Layers: topography, hydrography, geology, color. Version...
Chapter
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Полученные с использованием нового метода изотопной геохронологии – U-Th метода данные подтверждают позднеплейстоцен-голоценовый возраст последних извержений вулкана Эльбрус на Большом Кавказе, что ранее было установлено на основе результатов K-Ar датирования. Подтверждена потенциальная вулканическая опасность Эльбрусского центра. Анализ хронологии...
Article
The 238U/235U ratio was precisely measured in uranium minerals from 11 hydrothermal deposits of different geologic settings and ages situated in ore regions of Asia, Europe, Africa, and North America by MC-ICP-MS using a 233U-236U double spike. The spike was calibrated in reference to the CRM-112A standard with 238U/235U = 137.837 ± 0.015 (Richter...
Article
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In this paper we report the first results of petrological and isotope-geochemical studies of young lavas of the Porak neovolcanic center within the eastern part of the potentially active Vardenis volcanic area of the Lesser Caucasus (Armenia). According to a number of material characteristics, the newest lavas of the Porak neovolcanic center are cl...
Article
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The results of isotope-geochronological and petrological-geochemical study are reported for Neogene mafic intrusive rocks distributed in the northern part of the Lesser Caucasus (Georgia). It is shown that the young plutonic bodies were formed here in two magmatic stages: in the Middle Miocene (around 15.5 Ma) and in the terminal Miocene (9–7.5 Ma)...
Article
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The products of the activity of the Late Quaternary Kazbek neovolcanic center in the Greater Caucasus are studied by isotopic-geochronological methods. It is found that the youngest magmatism evolved during the last 400–450 k.y. over four discrete phases: 395–435, 200–250, 90–120, and less than 50 ka. The petrological-geochemical and published isot...
Article
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Using the high_precision technique of MC–ICP mass spectrometry, the isotope composition of lead was studied for the first time in sulfides of different mineral associations at the Verninskoe deposit that belong to large gold deposits of the Lena Province. In 23 monofractions of sulfides (pyrite, arsenopyrite, galena, and sphalerite), the Pb–Pb data...
Article
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We report new 15 lead isotope analyses performed on galena from different ore deposits in western Romania, by using a high-precision version of MC-ICP-MS method. The data were compared with already published data in the literature and split in 4 distinct groups in 206 Pb/ 204 Pb vs. 208 Pb/ 204 Pb and 207 Pb/ 204 Pb diagrams. Lead isotopes of the N...
Article
Owing to the rapid increase in available data on the natural variations of the 238U/235U ratio, new isotopic geochemical mark of redox processes are beginning to emerge. In this connection, numerical estimates of the 238U and 235U fractionation factor ( α (UIV–UVI)) accompanying the reduction UVI → UIV are needed. Such an estimate has been obtained...
Article
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The Darasun ore field situated in the southern West Stanovoi Terrane near the Mongolia–Okhotsk Suture comprises the Darasun (>100 t Au), Talatui (~38.2 t Au), and Teremki (3 t Au) lode gold deposits. In the opinion of many researchers, the Darasun deposit is spatially and paragenetically linked to granodiorite porphyry of the Amudzhikan Complex and...
Article
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The chronology of evolution of the young explosive volcanism in the Elbrus area of the Greater Caucasus is revealed. The isotopic–geochronological data indicate that ignimbrites and associated volcanic rocks were formed during the Middle Pliocene (3.0–2.75 Ma) and Early Pleistocene (0.84–0.70 Ma) stages of magmatic activity of the Greater Caucasus....
Article
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The isotopic (U-Pb, 238U-235U, 234U-238U) and chemical study of whole-rock samples and finegrained fractions of rocks in a vertical section of the terrigenous sequence at the Dybryn uranium deposit in the Khiagda ore field shows that a wide U-Pb isotopic age range (26.9-6.5 Ma) is caused by oxidation and disturbance of the U-Pb isotopic system in c...
Article
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The Štiavnica Stratovolcano in Central Slovakia is the largest volcano in the Neogene to Quaternary arpathian volcanic arc. A large caldera, an extensive subvolcanic intrusive complex and a resurgent horst with late stage rhyolite volcanites are the most characteristic features. The results of new K-Ar and Rb-Sr isotope dating using more sophistica...
Article
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Lead isotopic composition was studied at 12 deposits of eastern Transbaikalia, which differ in type and scale of mineralization. The high-precision Pb-Pb data obtained using multicollector inductively coupled plasma mass-spectrometry allowed us to outline two large lead isotope provinces spatially coinciding with the West Stanovoi and Argun tectoni...
Article
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New isotope-geochronological data (K-Ar, Rb-Sr) provide tight geochronological constraints on the history of Late Cenozoic magmatism on the southern slope of the Greater Caucasus. Several previously unknown, rhyodacite intrusive bodies with an emplacement age of 6.9 ± 0.3 Ma (Late Miocene) are reported from the Kakheti-Lechkhumi regional fault zone...
Conference Paper
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The Štiavnica Stratovolcano in central Slovakia is the largest volcano among Neogene to Quaternary volcanoes at the inner side of the Carpathian arc. Results of new K-Ar and Rb-Sr isotope dating using more sophisticated methodical approaches change our view on timing of volcanic and intrusive activity. Lifespan of the stratovolcano is apparently sh...
Article
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This paper reports on isotope-geochronologic, petrologic, and isotope-geochemical (Sr-Nd) studies of Quaternary magmatism in the Geghama neovolcanic area, Armenia, Lesser Caucasus. According to these studies, the period of youngest volcanic activity in the region lasted about 700 000 years, from 700 ka to a few tens of thousands of years ago. We fo...
Article
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The Miocene epoch is the most important, possibly key time range in the Cenozoic history of the Eurasian–Arabian collisional zone (EACZ), in which the Neotethys oceanic basin was finally closed, subduction under the folded structures of the Pontic Mountains and Lesser Caucasis was finished, and the “rigid” stage of convergence between the closed li...
Article
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A systematic study of Pb isotope composition was carried out for Elbrus Volcano, one of the Europe’s largest volcanoes, using high-precision method of multi-collector inductively coupled plasma mass spectrometry. The measurement error of Pb isotope ratios was estimated from the results of replicate analyses of international BCR-1 and AGV-1 standard...
Article
The paper describes a new high-precision method for the simultaneous precise determination of 88Sr/86Sr and 87Sr/86Sr ratios in a single portion of a geological sample by multicollector inductively coupled mass spectrometry (MC-ICP-MS). The isotope analysis is carried out with mass bias effect correction by a combination of internal normalization t...
Article
The MC-ICP-MS technique was used to study Ag isotope systematics in various silver and gold deposits. Owing to the correction of measured 107Ag/109Ag values in samples for the mass discrimination effect on the basis of the 108Pd/106Pd reference ratio, a precision of ±0.4ɛ (±2SD) was achieved. The 107Ag/109Ag ratio was determined in native silver an...