37 research outputs found

    Сучасні стратегії розвитку науки

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    Робоча програма з дисципліни «Стратегії розвитку науки» за спеціальністю 6.030302 «Реклама та зв’язки з громадськістю» галузі знань 0303 «Журналістика та інформація», освітньо-кваліфікаційного рівня «бакалавр». – 2016. – 48 с

    Mineral Resources of the Geothermal Sources of the North Caucasus

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    The growth in the world consumption of raw materials resources accompanied by depletion of ore deposits explains the interest of many countries in the mineral potential of thermal waters. The Russian Federation has vast stocks of geothermal resources, this said, 74.3% of reserves are located in the North Caucasus. The paper contains material indicating substantial hydromineral potential of the North Caucasus, exploitation of which will allow extending the raw material resources base of not only this region but also the country as a whole

    Volatile (S, Cl and F) and fluid mobile trace element compositions in melt inclusions: implications for variable fluid sources across the Kamchatka arc

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    Volatile element, major and trace element compositions were measured in glass inclusions in olivine from samples across the Kamchatka arc. Glasses were analyzed in reheated melt inclusions by electron microprobe for major elements, S and Cl, trace elements and F were determined by SIMS. Volatile element–trace element ratios correlated with fluid-mobile elements (B, Li) suggesting successive changes and three distinct fluid compositions with increasing slab depth. The Eastern Volcanic arc Front (EVF) was dominated by fluid highly enriched in B, Cl and chalcophile elements and also LILE (U, Th, Ba, Pb), F, S and LREE (La, Ce). This arc-front fluid contributed less to magmas from the central volcanic zone and was not involved in back arc magmatism. The Central Kamchatka Depression (CKD) was dominated by a second fluid enriched in S and U, showing the highest S/K2O and U/Th ratios. Additionally this fluid was unusually enriched in 87Sr and 18O. In the back arc Sredinny Ridge (SR) a third fluid was observed, highly enriched in F, Li, and Be as well as LILE and LREE. We argue from the decoupling of B and Li that dehydration of different water-rich minerals at different depths explains the presence of different fluids across the Kamchatka arc. In the arc front, fluids were derived from amphibole and serpentine dehydration and probably were water-rich, low in silica and high in B, LILE, sulfur and chlorine. Large amounts of water produced high degrees of melting below the EVF and CKD. Fluids below the CKD were released at a depth between 100 and 200 km due to dehydration of lawsonite and phengite and probably were poorer in water and richer in silica. Fluids released at high pressure conditions below the back arc (SR) probably were much denser and dissolved significant amounts of silicate minerals, and potentially carried high amounts of LILE and HFSE

    Petrological and chronological study of primitive high-Mg andesite from monogenetic volcanoes in the fore-arc region of northern Kamchatka Peninsula

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    Primitive high-Mg andesites (HMA) exhibit low FeO*/MgO (FeO*, total iron) and high Mg# (=100×Mg/(Mg+Fe)), and are thought to be generated by hydrous mantle melting (Kushiro, 1969). HMA, including sanukitoids of the Setouchi volcanic belt, have been recognized in many orogenic belts of various ages, and in several cases, constitute a part of ophiolite (Tatsumi, 2003). Therefore, occurrence of HMA in northern Kamchatka may have important implications on the tectonic setting of the peninsula and/or the melting condition underneath

    Olivine zoning in high-Mg basalts of the Shiveluch volcano (Kamchatka)

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    Shiveluch volcano located in northern Kamchatka erupted mainly high-Mg andesites during Holocene times. However, tephrochronologists found two Holocene tephra layers that are unusual for this volcano: a high-Mg middle-K basalts with an age of 7600 yr BP and high-Mg high-K basalt with an age of 3600 yr BP [Volynets et al, 1997]. The proximal outcrops for these two tephra deposits were discovered just recently [Churikova et al., 2010; Gorbach & Portnyagin, 2011]. Our study of olivines from the high-Mg basalts documents unusual Mg-Fe zonation [Gordeychik et al., 2016]: Inner cores of olivines from both eruptions show Fo87-92, falling to the rim to Fo75-85. In the outer cores of both basalt tephra, forsterite decreases linearly abruptly changing to a steeper gradient towards the rim. Electron microprobe element maps reveal the complex and highly unusual zoning features of these olivines. The inner cores of the olivines of 7600 yr BP tephra have bell-shaped distributions for forsterite and nickel. The maximum forsterite in their core can be up to Fo92, decreasing outward to the outer core to Fo86. At the same time, the trace elements in the inner core remain constant. Such element distribution is consistent with diffusion of Fe, Mg, and Ni in the initially uniform high Mg cores after the phenocrysts were changed to non-equilibrium in a less mafic melt. The shape of the inner cores suggests partial dissolution after magma mixing. The interfaces between the inner and outer cores are marked by abundant melt/fluid inclusions. The inner cores were overgrown by olivine with Fo90 when the crystals moved to the high-Mg melt. As result some olivine grains have the maximum forsterite values in the outer core. The specific feature of the olivine outer cores from basalt of the 7600 yr BP tephra eruption are concentric zones with higher values of Ca, Cr, Al, P. One of the crystals has five distinct growth zones with high Cr concentrations. The width of these zones can be only a few microns and thus such zones are often missed in typical quantitative point measurements in microprobe profiles. Inner cores of olivines from the 3600 yr BP tephra are uniform in forsterite and nickel. However, Al and Ca element distribution maps show in inner cores higher concentrations with rather smooth contours. This suggests that initially the olivines were formed from high-Al and high-Ca melt, then were dissolved and the overgrowth zonation has been smoothed out due to faster Mg-Fe diffusion. Only Ca and Al with low diffusivity were conserved. The concentric zones with higher element concentrations are not so well expressed in olivines from the 3600 yr BP tephra, but some distinct growth zones are also shown in Ca, Cr, and P. Information extraction and decoding of the elemental maps allow seeing highly complex growth-dissolutiondiffusion history of magma mixing processes prior to eruption. This research was supported by RFBR-DFG grant # 16-55-12040

    Petrology and geochemistry of the Tolbachik stratovolcano

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    The numerous of national and international publications were dedicated to Plosky Tolbachik volcano eruptions and adjacent monogenetic cones, which were erupted repeatedly during Holocene, including historical time [i.e. Vlodavets, 1937; Popkov, 1946; Peep, 1946, 1954; Menyailov, 1953; Sirin and Farberov, 1963; Kirsanov et al., 1974; Ivanov and Khrenov, 1979; Fedotov, 1984; Krivenko, 1990; Kersting, 1995; Tatsumi et al., 1995; Hochstaedter et al., 1996; Kepezhinskas et al., 1997; Turner et al., 1998; Pineau et al., 1999; Volynets et al., 2000; Churikova et al., 2001; Münker et al., 2004; Portnyagin et al., 2007; Volynets et al., 2013]. However, all these data mainly relates to monogenetic cones, but the information on stratovolcanoes itself practically absent. There are only few papers on Ostry and Plosky Tolbachik stratovolcanoes focusing on geology [Ermakov and Vazheevskaya, 1973], petrography and some petrochemistry of the rocks [Ermakov, 1977; Flerov and Melekestsev, 2013]. The modern geochemical and isotope studies of the stratovolcanoes were never achieved. In this report we present geological, petrographical, petrochemical, geochemical and some K-Ar data on the rocks of Tolbachik massif. The present report based on representative collection of 154 samples from stratovolcanoes, dikes, monogenetic cones of different ages, including last 2012-2013 eruption. Additionally our study included samples separately standing edifice of Povorotnaya mount, which age according to K-Ar dating is 0.306±0.01 Ма

    Khankala thermal water deposit of the Chechen Republic and resources for the implementation of geothermal circulatory systems

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    In the article, the perspective development of geothermal resources in the Chechen Republic is considered and data on the perspective Khankala deposits of thermal waters is stated. For the estimation on the feasibility of the creation of circulatory systems, the authors have created a 3D model of the most productive XIII layers of this deposit. This allows for proposals of possible locations of water-intake and water injection wells. In conclusion, recommendations for the location of the wells and the creation of a circulatory scheme of intake of deep heat in the Khankala deposit of thermal waters are given
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