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Moscow University Bulletin. Series 4. Geology

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No 6 (2018)
https://doi.org/10.33623/0579-9406-2018-6

3-17 929
Abstract

The new concept of cluster evolutionary mineralogy is based on the idea of the formation of the Earth from the primary stellar matter, which was preserved in the cores of the planets. The consequent destruction of it, as a result of the decay of heavy nuclear matter, leads to fragmentation of the substance until the appearance of superheavy elements with their further nuclear dissociation. As a result, a protomagma emerges, which enters the upper mantle in the form of plume flows. This process supports the reactions that result in the formation of chemical elements, minerals, ores and rocks, from which the upper mantle and the crust are formed. The processes of nuclear dissociation lead to the release of energy and the decomposition of matter, which initiates the growth of the earth's volume, its geotectonic activity, and the appearance of the hydrosphere and the atmosphere.

18-28 319
Abstract

As a result of paleomagnetic studies Sariolian 2,4–2,3 Ga conglomerates of the Onega basin of the Karelian protoctaton, two characteristic components of magnetization have been separated. Mean direction of the medium-temperature component has a heap distribution and coincides with mean direction of the Svecofennian remagnetization within the Karelian protocraton. The directions of high-temperature magnetization components isolated in conglomerates have a significant spread, which indicates the primary nature of this magnetization component. Two clusters of high-temperature components associated not only with the composition of protolites, but also with different conditions of rock transformations, including their fluid saturation, are distinguished.

29-36 318
Abstract

Analysis of new 3D and 2D seismic data made it possible to describe in detail the continental slope relief of the northeastern part of the Black Sea, and a large number of gravitational processes of various types. It is established that the final phase of the active lithodynamic processes development is due to the NovoEvksin regression of the basin associated with the last glaciation and completed its development more than ten thousand years ago. The irregularities formed as a result of late Holocene landslides also occur, but their contribution is insignificant, and the amplitude rarely exceeds 1 m.

37-44 344
Abstract

In Nakyn diamondiferous field of West-Yakutian province various fluid fracture rocks determined, including kimberlites, eruptive breccias of basites, fluid fracture carbonate breccias and accompanying fluidizite streaks. Shown their characteristic petrographic features and regularity of distribution in the rocks of the lower Paleozoic sedimentary cover. Revealed a predominant tectonic control of fluid fracture formations with bi — and confocal distribution. Suggested the formation of these fluid fracture rocks as a result of different ages directed at faults phreatic explosions.

45-50 354
Abstract

At least two outcrops of igneous rocks have been reported from the watershed of the Bodrak and Alma rivers (south-western Crimea). Previous studies suggested that these are intermediate to acidic volcanic rocks of pre-Middle Jurassic age. We compared the rocks from one of these outcrops with those from the near-contact area of the Middle Jurassic Dzhidairskiy intrusion, which is located proximally and predominantly consists of mainly of altered dolerites. It was determined found that the rocks from both locations were significantly altered as a result of the processes of acid metasomatism, down to quartz-carbonate-dikkite metasomatites. In this case, the nature of the changes and the appearance features of relatively unaffected by this metasomatism samples the most unaltered samples represented by altered dolerites are of the same type in both locations.

51-56 313
Abstract

Based on study of the lithology of the Taman Konkian, reflecting the accumulation of mainly clays, the two types carbonate rocks related to planktonogenic and microbial sediments were determined. Planktonogenic and microbial carbonate rocks have different carbon and oxygen isotopic compositions. Based on statistical processes, including Lomb-Scargle and REDFIT periodograms, cyclicities related to solar forcing were detected.

57-73 661
Abstract

Domanic (and domanicoid) deposits are in a great interest of researchers and oil companies, since they possess authigenic oil and gas content. The article presents the results of study outcrops in the Volga-Ural and Timan-Pechora basins. The stratigraphic interval included sediments from the Middle Frasnian stage of the Upper Devonian to the Turnasian stage of the Lower Carboniferous. The main types of rocks were characterized by microscopic examination of thin sections and geochemical parameters of organic matter. It is shown that the domanic deposits of the Timan-Pechora basin are similar in structure and lithological composition to the deposits of the Volga-Ural Basin. The upper part of the domanic section is distinguished by the predominance of the carbonate-siliceous type of rocks over the kerogen mixed varieties. According to the geochemical parameters, the organic matter in the rocks of the sheltered deposits of the Volga-Ural and Timan-Pechora basins belongs to type II, but on the outcrops of the Volga-Ural region, the organic matter of the high-carbon sequence is more mature than on the outcrops of Timan-Pechora basin.

74-81 493
Abstract

We present the results of studies of the internal structure of synthetic malachite aggregates obtained by two methods: in an open flowing (VNIISIMS, Mingeo USSR, Aleksandrov) and closed evaporation-recirculation (IEM RAS, Chernogolovka) systems. The internal structure and chemical composition of the malachite samples were studied using a Tescan Vega II XMU scanning microscope with an energy dissipation spectrometer (EDS) of INCA Energy 450. The results of the studies showed significant differences in the internal structure of malachite obtained by different methods. These differences are displayed mainly in the structure of malachite aggregates, and are due to different mechanisms of transport and deposition during malachite dissolution and crystallization.

82-92 371
Abstract

Geological structure and physic-chemical characteristics of the Stepninsky, Vandyshevsky, Biryukovsky and Uisky massives related to the Stepninsky monzogabbro-granosyenite-granite complex are described. A conclusion was made that the depth of crystallization of the granitoid massives changes in this row from hypabbyssal to hypabyssal-subsurface facies. It is shown that the intrusions of the complex belong to the intraplate type. At the early stage, the basicintermediate rocks of a deep-mantle genesis were formed, which can be regarded as a derivative of an individual plume; at the later stage they were changed by granites and leucogranites of the calc-alkaline type, formed as a result of anatexis of the lower crust. The rocks of the later stage have a rare-metal geochemical specialization.

93-101 1279
Abstract

The features of evaluation of the effectiveness of flow deflection technologies of enhanced oil recovery methods. It is shown that the effect of zeroing component intensification of fluid withdrawal leads to an overestimation of the effect of flow deflection technology (PRP). Used in oil companies practice PRP efficiency calculation, which consists in calculating the effect on each production well responsive to subsequent summation effects, leads to the selective taking into account only the positive components of PRP effect. Negative constituents — not taken into account and it brings overestimate over to overstating of efficiency. On actual examples the groundless overstating and understating of efficiency is shown overestimate at calculations on applied in petroleum companies by a calculation.

102-108 464
Abstract

Coalbed methane (CBM) is a new clean and unconventional energy that has broad space for development. In Qinshui basin, CBM reserves reach 3,97·1012m3, which is 10,8% of the total resource in China. Compared to the main coal basins of USA, Australia, Canada and Russia, coal seams in Qinshui basin have the characteristics of high metamorphism, high gas content, low porosity, low permeability and low reservoir pressure. Therefore, effective stimulation treatments must be used in Qinshui basin to realize industrial exploitation of CBM. At present, vertical wells with hydraulic fracturing are dominated in Qinshui basin. In addition, injection CO2, electric pulse, multi-stage fracturing and other technologies are also applied to the CBM exploitation.

109-116 326
Abstract

This article provides detailed information about the geological setting and the chemical composition of some thermal springs (Garm-Chashma, Firuza-MGU, Tandykul, Obigarm, Khojaоbigarm) located within the Pamirs and the Tien Shan mountain systems. This is the first report describing the micro components data for investigated springs obtained by the ICP-MS method. The calculated ratios of B:Cl, B:Br and Li:Rb:Cs allow to define the genesis of the studied thermal springs. New data on the contents of 18O and D indicate that the studied thermal waters are most likely meteoric, while a slight drift from the meteoric water line is the result of isotope fractionation in water-rock-gas processes. The estimated subsurface temperatures for these thermal waters vary from 136 °C to 240 °C based on the K:Na geothermometer.

SHORT MESSAGES

117-120 270
Abstract

Comparative study of the Late-Quaternary sedimentation on the platform and folded margins of the Black Sea is performed. Differences in the morphology of the seabed, in the supply of terrigenous material in combination with significant fluctuations in sea level caused differences in the structure of sediments, in their texture, mineralogical composition, thickness, combined different sedimentary mechanisms.

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ISSN 0579-9406 (Print)