pdf № 285, September

DOI: 10.19110/2221-1381-2018-9-3-9

The geological position and age of the Man’hobeyu suite in the Subpolar Urals are considered, which in modern stratigraphic schemes refers to the Lower or Middle Riphean formations and is considered as the basal deposits of the Upper Precambrian of this region, which is stratotype for the Precambrian of the entire Timan-Northern Ural region. Based on the results of new isotope-geochronological studies, taking into account the available geological data (structural, petrological, mineralogical), the rationale for the idea, that the Man’hobeyu suite cannot be regarded as an independent stratigraphic subdivision is given. It is a rock association of predominantly low-temperature diaphthorites and cataclasites in high-temperature metamorphites, analogous to those of which the Lower Precambrian Nyartin complex consists.

Isotopic-geochronological data make it possible to unambiguously classify the metamorphosed rocks, which is allocated as the Man’khobeyu suite, to the Lower Precambrian formations. At the same time, the most preferable assumption is the Early Proterozoic age of the protoliths of the metamorphic rocks of both the Man’khobeyu suite and the Nyartin complex.

Keywords: Subpolar Ural, Upper Precambrian, basal sediments, zircon, isotope age.

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DOI: 10.19110/2221-1381-2018-9-10-16

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 (Py_2–27Alm_1–68Sps_1–23Ca-comp_3–96) was represented by pyrope-almandine, almandine, grossular-almandine, spessartine-almandine and grossular-andradite. Orthopyroxene was characterized by a composition (Si⁴⁺ = 2.0—1.48, Al_total = 0.10—0.66 f. e.) the enstatite-alimentatie, and clinopyroxene – (Si⁴⁺ = 1.85—1.61, Al_total = 0.17—0.50 f. e.) the diopside-fassaite and (Al_total = 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, Al_total = 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.

Keywords: Ilmeny-Vishnevogorsky complex, metaultramafic rocks, garnet, alumoenstatite, fassaite, omphacite, glaucophane, phengite, chromespinelides.

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DOI: 10.19110/2221-1381-2018-9-17-23

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.

Keywords: resources, reserves, hydrocarbon deposits, subsoil use, geological exploration, seismic exploration.

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DOI: 10.19110/2221-1381-2018-9-24-29

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.

Keywords: accessory apatite, granite, the Nikolaihsor massif, the Subpolar Urals.

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DOI: 10.19110/2221-1381-2018-9-30-38

Based on the results of the core analysis of boundary Lower to Upper Devonian (D₁l-D₃tm) interval by X-ray fluorescence analysis supplemented with CO₂ determination and loss on ignition, X-ray diffraction analysis of clay fraction of the rocks and clays, electron microscopy and EDS, analysis of stable isotopes of carbonate carbon and oxygen, etc., we revealed lithological and mineralogical-geochemical features, which testified to the ancient influence of  infiltration water systems to the rocks during the ascent of previously submerged strata into the aeration zone.

In the sections studied, we showed a definite vertical geochemical zonation, expressed in changing zones from top to bottom: a) zone of marine slightly altered limestones; b) zone of hydrolysis and infiltration in argillaceous dolomites with signs of paleokarst; c) zone of secondary dolomites; d) zone of low-altered limestones. The established sequence is characteristic for the processes of regressive infiltration epigenesis and assumes the existence of a subaerial unconformity between a andb zones.

Keywords: subaerial unconformities, diagnostic features, infiltration epigenesis, Lower Devonian deposits, eastern flank of Khoreyver depression.

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DOI: 10.19110/2221-1381-2018-9-39-42

We have studied conditions influencing the results of the isotopic composition analysis of oxygen and carbon of carbonate skeletons of fossil ammonites, taking into account that they had been open for post-sedimentation processes. The object of study was shells of Ringsteadia, Eurasenia, Perisphinctes, Dichotomoceras, Cardioceras ammonites from outcrops on the right bank of the Unzhi River, near the city of Makaryev of Kostroma Region. The most probable reason for the difference in d¹³С_carb and d¹⁸O_carb values of ammonite shells from coeval belemnites, except for mineral affinity (calcite, aragonite), was the presence of «pure» authigenic calcite shells. The indicator of the isotopic composition of carbonates was determined not only by the nature and origin of source substances, but also by the fractionation of the isotopes in various processes during their formation. We supposed that the multistage sulfate reduction could have changed isotopic characteristics of the carbonate of the shells.

Keywords: ammonites, calcite, isotope composition, sulfate reduction.

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DOI: 10.19110/2221-1381-2018-9-43-45

Summary. The article continues the discussion on the fundamental concepts of mineralogy: mineral individual, mineral species, system of mineralogy. To maintain the methodological unity of this science, it should be accepted that the mineral individual must be ordered. The order may be different: translated, local, strict, weak, quasiorder, fractal... The definition of mineral species should be reviewed towards their synthesis in continuous mineral series, the boundaries of which in the given P-T-X conditions are determined only by the nature of the substance. To represent the system of mineralogy, it is necessary to consciously use logical constructions other than classifications: tolerance spaces, structures, etc.

Keywords: mineral individual, mineral species, system of mineralogy.

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DOI: 10.19110/2221-1381-2018-9-46-49

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.

Keywords: intermolecular bonds, phase transitions, crystallization, lattice structure, model of oscillating bonds.

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DOI: 10.19110/2221-1381-2018-9-50-57

The sorbents, offered by the world industry for solving environmental problems, are not effective enough by many parameters (selectivity, sustainability, etc.). It is necessary to search for natural materials, which are affordable, cheap, with a high sorption capacity for pollutants. We obtained information on the material composition, structural parameters and sorption properties of initial mineral raw and biogeosorbents using analytical centers of the Institute of Geology and the Institute of Biology (Komi Science Center, UB RAS). On the basis of the determined features of the physical and chemical properties of clay and zeolite rocks and microorganisms-oil destructors immobilized on them, which are part of BIOTRIN biological preparation, and experimental modeling of microcosms (mineral sorbent - strains of microorganisms), new materials with improved parameters were developed; their sorption characteristics and destructive properties were evaluated. We observed a high biodegradation of oil products by microbial cells.

Keywords: biogeosorbents, zeolites, clays, Biotrin, oil products, sorption.

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