Статьи журнала - Вестник геонаук
Все статьи: 1821
Статья научная
This article discusses the results of lithological and geochemical studies of the Artinskian deposits and organic matter, which is a part of the petroleum source rocks of the northern part of the Pre-Ural Foredeep of the Timan-Pechora Province. The rocks are very diverse in composition (clastolites, pelitolites, carbonatolites and mixtolites) and structural and textural features. Mixtoliths are widespread in shallow-marine environments (lower molasse deposits), which are associated with mixed terrestrial and marine organic matter. We recorded the predominance of poor and fair petroleum source rocks due to increasing terrigenous component. Mixtoliths of the Kochmes area (HI of 240 mg HC/g TOC) are characterized by the best generation potential. Organic petrography studies indicate the predominance of bituminite (sapropel base) in the composition of organic matter, the terrigenous components dominates in the eastern regions adjacent to the Urals.
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Oscillation of bonds in solid and liquid phases of substance and phase transitions
Статья научная
We propose a new approach to describe the structure of substance suggesting an oscillatory nature of interatomic (intermolecular) bonds. This approach develops a model of thermal oscillations and significantly expands possibilities for analysis and understanding of phase transitions. We revealed a temperature dependence of dynamics of the lattice of the bonds and its change in the process of phase transitions. By example of water we obtained data for the quantitative characterization of stable bonds at various temperatures.
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Статья научная
The relevance of detailed studying Givetian-Frasnian sedimentation is defined by a proceeding discussion about a level of the lower Frasnian Stage bound (according to border of Middle and Upper Devonian) in the Eastern European platform. New results of investigation in a boundary between Middle and Late Devonian within the Southern and Middle Timan presented. There are a correlation between even-aged palynocomplexes in adjacent territories; determination of the new palynozone, which details Lower Frasnian sedimentation; establishment of higher plants spores associations features formed in continental, coastal and sea facies.
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Photocatalytic nanoreactor based on low-dimensional titanium oxide structures
Статья научная
Synthesized titanium oxide nanotubes from titanium raw materials are efficient nanoreactors for photocatalysis in comparison with macroanalogues. The dependence of the geometry of titanium oxide structures on the redistribution of the density of electronic states was studied. The presence of natural iron ligands leads to the appearance of midgap states inside the bandgap of titanium oxide.
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Physical and chemical studies of the organic matter of Upper Devonian brown coals
Статья научная
We presented results of comparative physical and chemical studies of the organic matter of Devonian brown coals and rocks with carbonized plant residues from Northern Timan. We used IR Fourier spectroscopy of diffuse reflection, ESR spectroscopy, quantitative chemical analysis, pyrolytic gas chromatography-mass spectrometry.
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Статья научная
The actual task is to unite the efforts of scientists from different countries to find efficient sorbing materials and develop technologies for their production for purification of water systems, technogenic structures from radionuclides, heavy metals and other contaminants. The objects of the research are red mud (RM) from Ural aluminum plant and clay-salt slimes (CSS) from the 3rd mining factory of JSC «Belaruskali», which were studied by modern analytical methods. We estimated the application potential of the industrial wastes of bauxite processing (Russia) and sylvinite ore (Belarus) accumulated at enterprises of mining industry of these countries, in the technologies of rehabilitation of disturbed agroecosystem and purification of water environments and ecosystems from radionuclides.
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Rare minerals from metaultramafic of the Ilmeny-Vishnevogorsky complex (South Urals)
Статья научная
The article presents the results of studying peculiarities of chemical compositions of garnets, alumoenstatites, fassaites, omphacites, calcium and sodium amphiboles, chromespinelides, micas and zircons from metaultramafic rocks of Buldym, Ishcul, Nyashevo, Savelkul and Urazbaevo massifs of the Ilmeny-Vishnevogorsky complex. Minerals for research were selected from large (150-200 kg) samples were crushed to a fraction of 0.25 mm. The next stage they were brought to the concentrate followed by selection under the binocular microscope. Microprobe analysis of the mineral composition was performed on a raster microscope REMM-202М with microanalyzer by «SUCCU (IMin-ISR)». Garnet (Py2-27Alm1-68Sps1-23Ca-comp3-96) was represented by pyrope-almandine, almandine, grossular-almandine, spessartine-almandine and grossular-andradite. Orthopyroxene was characterized by a composition (Si4+ = 2.0-1.48, Altotal = 0.10-0.66 f. e.) the enstatite-alimentatie, and clinopyroxene - (Si4+ = 1.85-1.61, Altotal = 0.17-0.50 f. e.) the diopside-fassaite and (Altotal = 0.16-0.66, Na = 0.27-0.70 f.e.) omphacite. Chromespinelids corresponded to the composition (#Cr = 0.20-0.22 - 0.03-0.08, Altotal = 1.59-1.61 - 1.83-1.86 f. e. и #Mg = 0.67-0.70 - 0.70-0.75) spinel and later high-alumina spinel. The composition of minerals reflected polymetamorphical conversion metaultramafic rocks.
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Статья научная
We present a new regional event scale based on a generalized analysis of results of determination of event-stratigraphic boundaries of biotic events of various levels and 13C isotope anomalies in studied reference sections of the Subpolar Urals and the Chernov Uplift. The combined regional curve of carbon isotopic composition allows finding out several isotopic events in the Silurian.
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Sm-Nd isotopy of the dykes of the Vorontsovskoe gold-ore deposit (Northern Urals)
Статья научная
The Vorontsovskoye gold-ore deposit (Northern Urals) generally corresponds to the Carlin-type. One of the deposit features is the presence of numerous dykes of mafic and middle chemical composition, of normal and increased alkalinity. Sm-Nd isotope studies for the first time confirmed the dykes formation age 340 ± 35 Ma. These data can be indicative of the post-collisional stage of magmatism in this area. The positive eNd values suggest a probable abyssal magmatic source of Nd.
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Статья научная
Preliminary results of geophysical surveys for 2012-2013, along the banks of the river Sysola in Kirov Park Syktyvkar are presented.
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Technological mineralogy: from academician V. M. Severgin to the present day
Статья научная
It is shown that the origins of technological mineralogy in Russia are associated with the name of Academician V. M. Severgin, who at the end of the 18th century introduced the concept of «technological and economic» mineralogy. The stage of development of 1921-1955 is considered as important for the formation of the school of applied mineralogy. The next stage is the implementation of the principles of technological mineralogy in the practice of geological exploration and mining production and the creation of the Technological Mineralogy Commission of the All-Union Mineralogical Society by the beginning of 1983. The main directions of the development of technological mineralogy and the role of the published works of the commission are substantiated.
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The Holocene sedimentation in the North Antarctic peninsula area based on fossil diatoms
Статья научная
This paper is devoted to investigation of surface marine deposits of Core K98-09 which located in Drake Passage at a west of Elephant Island, Antarctic Peninsula. The research is aimed at studying the Holocene depositional environments based on diatom analysis. To study the fossil diatom assemblages, the material was treated in accordance with standard techniques. The research of the Holocene transformation of marine sedimentation conditions near Antarctic Peninsula is important owing to the rapid Late Quaternary climate changes. Due to the taxonomic composition and ecological structure of diatom assemblages the age of core deposits accumulation was determined as the Late Holocene (not early 2,400 yr), neoglacial stage. On the base of the species composition the core deposits were divided into two intervals. In the lower interval (18-45 sm) the dominance of cold-water and sea-ice diatoms is an indicator of the sea-ice environments. In the upper one (0-18 sm) the oceanic species prevalence that indicates the completele open-water environments with the warmer surface sea water. Our scientific research into the Holocene sedimentation conditions has enhanced the understanding of the Late Quaternary Antarctic palaeoclimate variables.
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Статья научная
A number of outcrops located in the basin of the Bol'shaya Nadota River (Subpolar Urals) supply a unique possibility to study the Middle Palaeozoic isolated carbonate platform and to reconstruct its composition and development. The Middle Devonian - Lower Carboniferous sequence of the region is represented by the Middle Devonian Nadotamylk Formation composed of argillites and siltstones overlaid by clayey carbonates, the Frasnian Matyashor Formation composed of detritic and organogenous limestones, the Famennian-Tournaisian (?) Bolshaya Nadota Formation comprising oolitic limestones, Izvestnyakovo-Dolomitovaya and Izvestnyakovo-Brtekchevaya formations of the Late Visean - Serpukhovian age composed of detritic, clastic, and oolitic limestones, and the Olysya Reef of the Late Visean - Serpukhovian age. Three facies belts possessing different evolution of the sedimentation are detected in the area under consideration. The Eastern and Central facial belts are dominated by organogenous buildups, and the detritic and oolitic limestones are characteristic for the Western facial belt. These facies compose the Bol'shaya Nadota shoal (isolated carbonate platform) similar to Great Bahamas Bank. Elaborated models of evolution of sedimentation reflect development of buildups and surrounding areas in the Early Frasnian - Serpukhovian time. Composition of the Bol'shaya Nadota shoal and distribution of biota suggest a warm-water environment for the isolated carbonate platform.
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The apatite of the Nikolaishor granite massif (the Subpolar Urals)
Статья научная
The paper presents the results of the typomorphism and chemical studies of accessory apatite from the Nikolaishor granite massif. Two types of the fluor-apatites were revealed in the rocks of the considered massif. According to the morphological features a hexagonal dipyramidal prismatic apatite was formed at the early stage of formation of the Nikolayshor massif under higher temperature conditions than the hexagonal prismatic apatite. The application of the saturation thermometer of Watson with the specification Bea allowed determining temperature of the Nikolaihsor granite massif formation. two temperature ranges (751-877 °С and 634-699 °С) in the rocks of this massif were revealed.
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Статья научная
The article describes the trends in the process of reproduction of the mineral resource base, the results of monitoring of geological exploration in the region in recent years. On the basis of the state branch programs and strategy of social and economic development of the region stages of research of prospects of oil and gas potential are allocated. The current situation is analyzed and recommendations are given on the effective development of the resource base of the republic. There is an increasing role of individual enterprises-subsoil users in filling the raw material base of the industry. It is concluded that in order to maintain the achieved level of oil production in the Komi Republic it is necessary to conduct exploration not only by subsoil users, but also at the expense of state subsidies.
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The evolution of the first forests in the Devonian
Статья научная
In recent years much new data have been obtained regarding the earliest trees, and their ecology in early forest ecosystems. Aspects of this new data are summarised below, concentrating on the Mid Devonian and earliest Late Devonian, c. 390-380 million years ago, before the dominance of Archaeopteris . The arborescent cladoxylopsids, archaeopteridaleans and lycopsids are considered, as well as the recumbent but large woody aneurophytes. Until now, cladoxylopsid dominated forests, cladoxylopsid/aneurophyte forests, early Archaeopteris , and lycopsid forests are the four forest types identified, largely on the basis of near coastal, wet environments. True in situ fossil forests are extremely rare during this time interval. Future research aims to identify further forest types, to better understand their relationship to palaeogeography and sedimentary environment, and to spread the understanding of early forests beyond the Old Red continent.
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Статья научная
The lithological composition and algae in the «Un'inskaya peschera» section of Lower Carboniferous carbonates were observed. Specimens of the genus Kamaena in Serpukhovian deposits of this section were determined, in spite of the fact that they became extinct to the Late Visean on the rest territory of the Urals. A factual material analysis pointed that asynchronous tectonic movements in the Un'ya River basin resulted to the formation of local, probably, isolated area with dominant still water conditions during Late Visean-Serpukhovian ages. These conditions caused a wide distribution of green algae of genus Kamaena in Serpukhovian.
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The inclusion of gold in accessory zircon of the Kozhim granitic massif
Статья научная
The crystals of zircon can reveal information about their formation environment due to their resistance to external influence and also inclusions observed of them. Zircon can contain different mineral inclusions: biotite, plagioclase, quartz, аpatite, etc. However no information about gold inclusions has been available in the zircons from granites of the Sudpolar Urals. The study results of the inclusions of gold in accessory zircon of the Kozhim granitic massif are presented in this paper. The studied mineral is a dark-brown translucent short-prismatic crystal containing an inclusion of gold and nodules of quartz. According to our studies, the inclusion of gold formed during the growth of zircon and it is gold covered with a thin film of oxide gold. It was confirmed that the crystallization of the studied zircon occurred at a temperature of 800 °С and above at the stage of formation of granites of Kozhim massif. We suggested the presence of an additional temperature mode when the temperature decreased to 700 °C and below during the postmagmatic stage.
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