pdf № 269, May

DOI: 10.19110/2221-1381-2017-5-3-13

The results of study of phosphate-bearing carbonaceous quartzites of the Polar Urals are presented. The rocks underwent low-temperature regional and deformation metamorphism. The carbonaceous matter is graphite. The rocks show an increased content of V, Cs, Te and heavy rare earth elements (Gd, Dy, Er). Rare-metal minerals, sulfides, rare-earth carbonates, Mn-Pb-Fe and Fe-Pb hydroxides, and Fe-Pb-Cu-Ni polymetal composition were revealed. Minerals were formed due to mobilization of elements caused by dislocation metamorphism and exogenous effects. It is established that the source of phosphorus is volcanogenic-biogenic.

Keywords: Polar Urals, phosphate carbonaceous quartzites, Middle Riphean, mineralization, carbonaceous substance.

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DOI: 10.19110/2221-1381-2017-5-20-30

Our study of the geochemical composition of the Upper Proterozoic metamorphosed volcanic-sedimentary rocks of nyaroveyskaya series in Central tectonic zone of the Polar Urals established that they had been formed in marginal-oceanic setting, possibly in back-arc marine geodynamic conditions.

In the western area of distribution of nyaroveyskaya series the metabasalts are represented by high Fe tholeiites, whereas in the east — high Mg. They are geochemically similar and close to the composition of E-MORB basalt, supporting similar conditions of generation of the magmatic melt. Low Nb, Zr, and Hf contents of in the metabasalts indicate a supra-subduction nature of these formations. Metasedimentary rocks contain metapelite, metagraywacke and quartzite. Carbon and carbon-free quartzites correlate well by the content of rare earth elements. Carbon quartzites contain terrigenous-clastic and silicon varieties. Metamorphosed quartz sandstones occur only in the western area. Analysis of the geochemical composition of metaterrigenous nyaroveyskaya series suggested that their formation resulted from destruction of silicon-rich sedimentary rocks with the participation of acidic, medium and basic magmatic rocks of Early Proterozoic continental crust.

Keywords:nyaroveyskaya series, oceanic crust, back-arc basins, rare elements.

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DOI: 10.19110/2221-1381-2017-5-31-42

Development in synergetic sense of the ideas of V. I. Dragunov and D. V. Rundqvist on the rocks unit cells and Academician M. A. Sadovsky on the geophysical medium discreteness («natural lumpiness») has led to the establishment of a new rock macroscopic stereological phenomenon — primary lumpiness, or frustumation (from Latin frustum — lump) firstly in rock samples with simple mineral composition and genesis, and later in rocks with polymineral composition and polygenic. Preconditions of this rock phenomenon discovery are contained in the works of S. M. Beskin, A. G. Zhabin, I. S. Delitsyn, A.N. Nikitin, O. A. Sustavov, V. V. Indutny and M. Yur. Povarennykh, and much earlier in the works of D. S. Korzhinskiy on the local («mosaic») equilibrium during disequilibrium natural geological processes and several works of F. Yu. Levinson-Lessing. 

In order to reveal the petrophysical essence of the rock frustumation, we successfully conducted a complex of different scale investigations (from nano- to decimeter levels) of rocks with simple mineral composition and genesis with the help of traditional mineralogical-petrographical methods (polarization microscopy, UV-luminescence, X-ray- and microprobe analyses) as well as neutronographic investigation of rock fabric, laser-ultrasonic echoscopy, ultrasonic tomography, and scanning electron microscopy.

Keywords:primary lumpiness, frustumation of rocks, neutronographic investigation of rock fabric, laser-ultrasonic echoscopy, ultrasonic tomography, ultra-violet luminescence, scanning electron microscopy.

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DOI: 10.19110/2221-1381-2017-5-43-48

Shielding properties of carbon materials are studied in connection with their wide possibilities to solve the problems of biological and technological effects of electromagnetic radiation. Shungite is the most interesting geological object for such studies. In the present work we present the results of study of the reflection in the microwave range of 26–39 GHz from thin plates made from solid pieces of shungite rocks with different carbon contents (from 3 to 95% by weight). We determined that static and dynamic conductivity differs in this frequency range. A sharp increase of dynamic conductivity occurs in the carbon content range 30–50 wt. %, while the static conductivity increases monotonically. The influence of carbon content and mineralogy-petrographic texture of shungite rocks on their reflective properties is considered.

Keywords: shungite rocks, microwave radiation, reflecting properties, static and dynamic conductivity.

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DOI: 10.19110/2221-1381-2017-5-49-53

The efforts of applied mineralogists and chemists are combined to produce sorbents that are competitive in the world market. Modern methods were used to study the physical and chemical (technological) properties of natural sorbents. We observed the technologies of modification of analcime-bearing rocks to increase the efficiency of pollution prevention and remediation of aquatic systems. We presented a comparative evaluation of sorption-filtering properties of analcime-bearing rocks and quartz sand to improve the process of purification of drinking and waste water from various types of pollution.

Keywords: natural sorbents, aquation systems, analcime-bearing rocks, quartz sand, physical and chemical properties.

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