pdf № 261—262, September—October

We have studied the composition of aliphatic and aromatic fractions of kerogen pyrolysis products from Timan-Pechora basin domanik rocks characterized by different levels of thermal maturity of its organic matter. We determined regularities of changing pyrolysate composition with the growth of OM catagenesis, which were confined in the reduction of concentrations of n-alkanes and n-alkenes-1, n-alkylnaphthalenes and n-alkylbenzenes. By the middle of the main phase of oil formation the sulphur structures completely disappear from the kerogen matrix. In the most mature specimens of domanik kerogen the content of aliphatic hydrocarbons is comparable to their content in immature kerogen of Upper Jurassic shales from the East European platform, reflecting a good residual hydrocarbon potential of organic matter of catagenetically altered domanik deposits.

Keywords: kerogen, Domanik deposits, thermal maturation, pyrolysis.

DOI: DOI: 10.19110/2221-1381-2016-10-3-7

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Results of study of structures and composition of Middle Carboniferous phosphorite concretions in the Lemva paleotectonic zone are presented. The complexconstruction of the geological section is shown and Middle-Late Carboniferous fossils are presented. A variety of calcium phosphate microstructures (cryptocristalline, coagulatio-clotted, microbiomorphic, radiated) which is classified as a carbonate fluorapatite, and a version of its formation is suggested.

Keywords: Lemva paleotectonic zone of the Urals, Middle Carboniferous deposits, Yayyusuite, phosphates, fluorapatite.

DOI: 10.19110/2221-1381-2016-10-8-15

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We have studied carbonaceous rocks of Nyarovey series (Polar Urals) to clarify their metallogenic specialization and establishment of the genesis of ore formations. Carbon material in shales presents graphite, the average values of the temperature of its formation, amounted to about 500 °C. REE Uranium-Thorium, sulfide, sulfate and copper mineralization has been identified. Formation of ore minerals is associated with metamorphic, and late postmetamorphic oxidation processes.

Keywords: metallogeny, carboniferous shales, nyarovey series.

DOI: 10.19110/2221-1381-2016-10-16-21

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In the Bezymyanny Creek Silurjan section there are some problems of deposits dating, as far as clear lithological markers are not available and fauna complex is combined. Deposits are Wenlockjan dated based on brachiopod and coral fauna, conodont complex is Wenlockian and Llandoverian mixed. The paper presents results of Stromatoporoid complex researches that contain 11 species. One species is indicative for Wenlockjan, five for Ludlowjan and five are widely spread in Wenlockjan and Ludlowjan both. A rich stromatoporoid complex completes the faunistic characteristic of section and proves uneasy environment and importance continue dating research.

Keywords: Stromatoporoids, Silurian, Chernov Swell.

DOI: 10.19110/2221-1381-2016-10-22-31

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Petrophysical properties of the metavolcanites from the Matert Fm of the Pechenga palaeorift structure and the massif rocks of western Lake Chudzyavr have been studied. Metavolcanites of the Pechenga structure are metamorphosed at prehnite-pumpellyite and massif rocks of Lake Chudzyavr — at amphibolite facies. An assessment of the rock elastic anisotropy by the acoustopolariscopy method has been made, the densities, compression and shear wave velocities et al. have been determined in lab conditions. The simulation of density, velocity characteristics of the rocks has been carried out in order to assess their deep properties. According to the laboratory studies, the samples of prehnite-pumpellyite facies show greater densities, compression and shear wave velocities than those of amphibolite facies. It was shown that the model (calculated) densities, velocity characteristics of the massif rocks from Lake Chudzyavr were much greater than the experimental data. A comparison of the acoustopolarigrams shows that using the acoustopolariscopy method one can visually distinguish rocks of prehnite- pumpellyite facies from those of amphibolite facies of metamorphism.

Keywords: rocks, metamorphism, density, velocity, anisotropy, acoustopolariscopy.

DOI: 10.19110/2221-1381-2016-10-32-38

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Phosphorite concretion and enclosing siliceous rocks in the Sezym Fm. of the Kosyu-Rogovaya Depression of the Pre-Urals Foredeep for the first time we found. Our studies showed that the Sezym Fm. was composed by mixtolites, carbonate, clayey, terrigenous and siliceous rocks. Phosphorites are only in one section. According to analytical data carbonateapatite, calcite and quartz are rock-forming in the concretions. These concretions can be used as marker bed for a correlation with analogous sections of the Pre-Urals Foredeep.

Keywords: Kos'yu-Rogovaya Depression, Lower Permian, Sezym Formation, phosphorite concretions, marker bed.

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The paper presents the results of study of the PGM mineralization, associated with the copper-nickel sulfide ores using electron microscopy and, for the first time, X-ray microtomography methods for Savabeysky ores located within Khenguryu gabbro-dolerite complex of Pay-Khoy. PGM mineralization is represented by bismuth-antimony and antimony-bismuth palladium tellurrides, kotulskite, sperrylite, hessite, bismuth-telluride and gold.

Keywords: Ugra Peninsula, Pay-Khoy, Khengur gabbro-dolerite complex, sulfide copper-nickel mineralization, SEM, XCT, sulphides, platinum group minerals.

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The results of mineralogical investigation of globular phyllosilicates (glauconite and mixed-layer minerals) from the Chim-Lоptiuga pyroschist deposit are presented. Grains were studied using modern chemical and physical methods: X-ray diffraction, scanning electron microscopy (SEM), microprobe analyses, infra-red spectroscopy.

Special attention was given to the crystal-chemical features of mineral and processes of glauconite formation in the producting rocks.

Keywords: glauconite, smectite, mixed-layer minerals, formations of phyllosilicates.

DOI: 10.19110/2221-1381-2016-10-52-57

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