S. N. Bubnov's research while affiliated with Russian Academy of Sciences and other places

Publications (29)

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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».
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...
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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
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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...
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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....
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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...
Conference Paper
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Приэльбрусье является одним из тех немногих районов Кавказа, где неоген-четвертичный игнимбритовый вулканизм проявился в значительных масштабах. Покровы игнимбритов и ассоциированных с ними пирокластических пород сохранились в виде небольших останцов на западе, востоке и северо-востоке этого региона в верховьях рек Малка, Чучхур, Чомарткол, Бийтик-...
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The actual collective monograph presents the results of both theoretical and experimental studies of actual problems of modern geophysics in order to mitigate issues on seismic hazards and consequent risks on the territory of Russian Federation. New methods and technologies for mitigation of possible catastrophic events, including manifestations of...
Article
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This paper reports an integrated petrological, geochronological, and isotopic geochemical study of the Pliocene Dzhimara granitoid massif (Greater Caucasus) located in the immediate vicinity of Quaternary Kazbek Volcano. Based on the obtained results, it was suggested that the massif has a multiphase origin, and temporal variations in the chemical...
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The monograph considers empirical relations in the evolution of volcanism in Eurasia and analyzes the effect of volcanism and impact events, which have similar consequences, on the environment and climate. The monograph consists of two parts. The first part presents the analysis of data on the Recent volcanism of Northern Eurasia, including a GIS m...
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The results of isotopic-geochronological study of the Pliocene volcanic rocks in reference sections and volcanic edifices of eastern part of the Javakheti Highland (the northwestern Lesser Caucasus) are considered. The isotopic-geochronological data obtained here are correlated with data on western part of the Javakheti Highland, which have been co...
Article
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Isotopic-geochronological study of the Pliocene magmatic activity in western part of the Javakheti Highland (northwestern region of the Lesser Caucasus) is carried out. The results obtained imply that the Pliocene magmatic activity lasted in this part of the highland approximately 2 million years from 3.75 to 1.75–1.55 Ma. As is established, the st...
Article
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The paper reports newly obtained K-Ar isotopic-geochronological data on the age of three lava flows (Khrami, Mashavera, and Kura), which begin at the Javakheti volcanic highland in southern Georgia. All of the dated rocks, including those from the Kura Flow, which was previously considered as the Pleistocene, are demonstrated to have a Pliocene age...
Article
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The results of detailed isotope-geochronological investigation of dacites from datum sections of lava flows at Elbrus volcano southern slopes allowed reconstruction the chronology of volcano eruptions. It is established that Elbrus volcano is not continuously active but has complex multistage evolution history. Volcano was active during recent 225±...
Article
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The specified on the basis of K-Ar data magmatic activity phases in manifestation time coincide with certain activity phases of other large latest-volcanism centers at Greater Caucasus - Elbrus and Kazbek. The initial volcanic activity phase (225-175 thousand years ago) was marked by extrusion bodies formation in different parts of the region. In t...
Article
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K-Ar and Rb-Sr isotopic geochronologic data were first used to constrain the timing and duration of magmatic activity at modern volcanic centers in the Greater Caucasus. The main dating technique was a modification of the K-Ar method with the utilization of low-background high-precision equipment and a technique that ensures the reliable analysis o...
Article
Rock-forming minerals of the pyroxene group provide important genetic information, which is " recorded" in certain subtle compositional and structural features of the minerals. The crystallization trends or the character of compositional variations from the cores to margins of solid-solution crystals reflect variations in the temperature, pressure,...
Article
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The aim of this paper was to report and discuss the data available for the K-Ar dating of effusive rocks from a few centers of recent volcanic activity in the Kazbek region (Great Caucasus) of the Caucasian segment of the Mediterranean (or of the Alpine-Himalayan) mobile belt separating the African-Arabian and European platforms. These data were ob...
Article
The composition of clinopyroxene in rocks of the upper volcanic sequence of the Imennovskaya Formation (0- to 430-m section of the Ural Superdeep Hole SD-4) allowed us to reveal the style and conditions of deep-seated and superficial magma differentiation. The volcanic rock series of the sequence composes the upper part of the Imennovskii Complex o...

Citations

... is approximately located on the northern slope of Aragats volcano (depth of ~7 to 13.66 km), which may be the reason for the existence of magma. Based on I.V.Chernyshev et al., 2002 and Vadim Milukov et al., 2018 studies, the Aragats center, one of the largest Quaternary volcanic centers in the Caucasus, is con ned to the Aragats neovolcanic area located in the western part of Armenia, at the intersection of tectonic zones of a general Caucasian extension and the sublongitudinal Transcaucasus uplift. The development of the Pliocene-Quaternary volcanism of the Aragats area is de ned by complex late collisional Geodynamics, which is related to global processes of the convergence of Eurasian and Arabian continental plates. ...
... These Late Ordovician to Early Devonian volcanic arc complexes are believed to be of intra-oceanic origin (Yazeva, Bochkarev, 1996;Puchkov, 2009). Some geochemical signatures of the Late Silurian to Early Devonian igneous rocks (high Zr/Hf, Nb/Ta, La/Sc, Y/Zr ratios and ASI, low Cr, Ni, Co, Sc contents) indicate that a less depleted mantle was involved in the melting, with limited influence of aqueous fluid on the mantle protolith (Sazonova et al., 1997). Crustal contamination of melts (causing high Th/Ta, K/Ti, Ba/Nb, Pb/Nb ratios) was recorded for the rocks of the Tura suite (Nosova et al., 2002;Narkisova, 2005). ...
... It is overlain by the Upper Silurian andesite-basalt suites. These calcalkaline rocks are replaced upwards by subalkaline differentiated basalt-trachybasalt-trachyandesite-trachydacite and then by weakly differentiated trachybasalt-trachyandesite volcanics (Vikentyev, 1996;Bochkarev, Yazeva, 2000;Nosova et al., 2000). The later Pridoli -Lochkovian high-K Tura volcanic suite belongs to the shoshonitic series. ...
... To find out how much the surface has elevated since the beginning of the Early Paleolithic measured values of incision of recent rivers into the reliably dated Early Pleistocene lava flows (K-Ar dates 2.65-1.7Myr) [16,23] have been taken as minimal magnitudes of uplifting. Various traces of local tectonic deformations and rearrangement of drainage systems were studied too [16]. ...
... It is seen on the Sr-Nd isotopic diagram ( Fig. 9) that the studied dacites are similar to other young magmatic rocks from different parts of the Lesser Caucasus (Lebedev et al., 2003(Lebedev et al., , 2007(Lebedev et al., , 2013b(Lebedev et al., , 2018bMeliksetian, 2012;Bubnov et al., 2014;Neill et al., 2015), forming with them a common field. In terms of Sr isotopic composition, they are factually identical to the phase I basalts of the Javakheti highland. ...
... It can be explained by the fact that this village receives drinking water from rivers originating from the slopes of Elbrus. Elbrus is considered a dormant volcano (Chernyshev et al., 2014). We have already noted that the waters of upper rivers originating from the slopes of Elbrus are characterized by a high content of aluminum (Reutova et al., 2018). ...
... The Kazbek (Mkinvartsveri), Keli, Elbrus ( Fig. 12.1), Kabardjina and Djava (Dzau) neovolcanic centres as well as of some other volcanos, erupted several times; Quaternary volcanic activity is also reported in the Lesser Caucasus (Pasquaré et al. 2011). Previous research (Burchuladze et al. 1976;Chernyshev et al. 2002Chernyshev et al. , 2008Vashakidze et al. 2019) has enabled to assess Holocene volcanic activity at the Kazbek and Elbrus volcanic centres, and thus the existence of volcanic hazard in the Greater Caucasus. This prompted the need for multidisciplinary geological, geophysical, petrological-geochemical and isotope studies regarding the Quaternary magmatic activity in this region. ...
... Its intense magmatic activity led to the formation of numerous large (up to 15 km) and thick (up to hundreds of meters) lava flows, the long upper ones reaches the Tergi River. On the periphery of the main cone, there are more than ten volcanic edifices of different ages, including monogenic and polygenic scoria cones, extrusive domes and small explosion centers (Chernyshev et al. 1999). The Kazbeki Center is located in the southeastern sector of the volcanic area in the axial part and on the southern slope of the sublatitudinal Khokh Range (one of the links of the Lateral Range). ...
... It evolves from the Minaralvodes volcanism with the age of 7-5 Ma (Lebedev et al., 2006) to Chegem zone with the age of volcanism of 4-3 Ma (Gazis et al., 1995), Tyzyl lava flows of $0.9 Ma (Hess et al., 1993), and to the youngest Elbrus volcanic complex. The activity of Elbrus started approximately 800,000 years ago and its most recent eruptions are dated back to the age of 20 Ka (Chernyshev et al., 2001). Another volcanic complex of the Great Caucasus, the Kazbegi volcano group, includes several granitic outcrops with the ages of 5-3 Ma distributed along the Great Caucasus range and a group of Quaternary volcanoes including Kazbegi (455-30 Ka), Kabarjin (300-220 Ka) and . ...
... In principle, this situation can be improved by increasing the amount of argon involved into the analysis, but an increase in the sample weight above 100–200 mg is very undesirable for modern low-background extraction systems. Our studies and the results of other authors on the dating of young volcanic rocks (Chernyshev et al., 1999Chernyshev et al., , 2001Chernyshev et al., , 2002a Lebedev et al., , 2004a Lebedev et al., , 2004b Lebedev et al., , 2004c Matsumoto and Kobayashi, 1995; Guillou et al., 1997; etc.) allowed us to quantitatively estimate the typical errors of argon isotope analyses obtained in recent studies by mass spectrometers with an absolute sensitivity of about 10 –3 A/Torr in static mode. During the measurement of 40 Ar/ 36 Ar, which is usually within 295.5–370.0 in the total argon of Quaternary volcanics, the precision of results of parallel analyses of different argon portions extracted from a single sample is 0.2– 0.5%. ...