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Volume 72, Nº 1 (2017)

Article

The place of ecological–geophysical studies in the system of urban ecology

Trofimov V., Zhigalin A., Bogoslovsky V., Arkhipova E.

Resumo

According to the forecasts of the World Health Organization, 70% of the world’s population will have lived in large and small cities by 2050. This means that more than two-thirds of the planet’s population will become a part of new natural-technical formation, that is, geobiotechnoecosystems. Such ecosystems are characterized by profound changes in natural properties during active human impacts and by acquiring new qualities. The changes manifest themselves in all ecological functions of the terrestrial spheres: the atmosphere, the hydrosphere, and the lithosphere, including a change in the geophysical (energetic) potential as well. The presented material can be considered as a basis for the formation of Geophysical Urban Ecology, which is a new scientific and practical field.

Moscow University Geology Bulletin. 2017;72(1):1-7
pages 1-7 views

Paleogeographic conditions in the West Siberian Basin during the Tithonian–Early Berriasian

Stupakova A., Stafeev A., Suslova A., Gilaev R.

Resumo

Based on facies, structural, and general paleogeographic analyses, new models of the bottom topography and accumulation of the Tithonian–Early Berriasian Bazhenov Formation (West Siberian Basin) are proposed. According to these patterns, quite a low proportion of the terrigenous material in the high-carbon facies of the Bazhenov Formation can be explained by its accumulation in relatively deep troughs that frame the uplifted shallow-water central part of the West Siberian basin. In addition, the structure and dynamics of ocean currents are considered. During the Tithonian–Early Berriasian, these currents were related to the aeration stages of bottom waters enriched in hydrogen sulfide and carbon dioxide. As a result of the convection of the water mass suffocation periods occurred.

Moscow University Geology Bulletin. 2017;72(1):8-17
pages 8-17 views

Bitak conglomerates as a clue for understanding the Middle Jurassic geological history of Crimea

Nikishin A., Gabdullin R., Makhatadze G., Khudolei A., Rubtsova E.

Resumo

The Bitak Formation is located in Crimea in the area of the city of Simferopol. It is mainly represented by weakly sorted conglomerates. The lithological description of the conglomerates is given. New data on the age of detrital zircons are presented. The possible age of the Bitak Formation is discussed. It is shown that the Bitak Formation is older than Late Bajocian volcanic rocks and younger than deposits of the Tauric Formation and its analogs of the same age. The Bitak Formation was accumulated in a pull-apart basin. Several basins of such a type are found in Crimea. It is thought that the Bitak basin was located at the base of the Middle Jurassic island-arc complex of Crimea.

Moscow University Geology Bulletin. 2017;72(1):18-27
pages 18-27 views

Late Carboniferous lycopsids of the Karantrav locality (the Southern Urals)

Orlova O., Tevelev A., Mamontov D., Anikeeva E.

Resumo

Numerous plant remains as the imprints of lycopsid strobili and stems and the sporadic imprints of articulate stems were first found in the Upper Carboniferous deposits from the Western Slope of the Southern Urals (Karantrav Settlement area). The brief stratigraphic characteristic of the studied locality is given. The studied plant assemblage is represented by Lepidodendron ophiurus Brongniart, L. vaselgense Anikeeva et O. Orlova, sp. nov., Lepidodendron sp., Lepidostrobus tevelevii O. Orlova, Mamontov et Anikeeva, sp. nov., L. ronnaensis Bek et Oplustil, Knorria sp., Calamites sp., and Mesocalamites ramifer (Stur) Hirmer. In-situ microspores of the Lycospora type were discovered in the sporangia of some strobili of the genus Lepidostrobus. Four lycopsid species (two are new) were described.

Moscow University Geology Bulletin. 2017;72(1):28-36
pages 28-36 views

The geological background of the May 12, 2008 Ms 8.0 Wenchuan catastrophic earthquake, Longmen Shan, Western China

Liu J., Koronovsky N.

Resumo

The Longmen Shan fault zone is located at the particular boundary between the Triassic Songpan-Ganzi orogen of the Qinghai-Tibetan Plateau and the stable Sichuan basin of the Yangtze platform. There are four major active faults and three tectonic nappes in this region. According to an analysis of neotectonics and historical earthquakes, the Longmen Shan fault zone presents a high level of seismic hazard. The rupture system that hosted the Wenchuan earthquake is characterized by thrust and dextral strike-slip movement.

Moscow University Geology Bulletin. 2017;72(1):37-45
pages 37-45 views

The relationships of thrust and shear deformations in the southern part of the Polar Urals as indicated by petromagnetic data

Sychev S., Veselovskiy R., Khudoley A., Kulikova K.

Resumo

Based on the petromagnetic characteristics of rocks that crop out within the Main Ural Fault zone (MUF) and Voykar–Synya ophiolites the multistage pattern of deformation processes in the study areas has been established. An analysis of the anisotropy of magnetic susceptibility of rock minerals detected the orientation, which allows us to reveal magnetic orientations in minerals recorded as a results of thrust (overthrust) and strike-slip deformations at an early stage of the evolution of the Ural orogenic belt. The main axes of the ellipsoid of anisotropy of the magnetic susceptibility (AMS) associated with regional thrusting, namely, the main stage of formation of the structure of the Urals, have rarely been revealed. This is evidence that thrust petrofabrics are almost completely veiled by superimposed shear deformations.

Moscow University Geology Bulletin. 2017;72(1):46-55
pages 46-55 views

Method peculiarities of multielemental analysis of rocks with inductively-coupled plasma mass spectrometry

Bychkova Y., Sinitsyn M., Petrenko D., Nikolaeva I., Bugaev I., Bychkov A.

Resumo

Decomposition of samples with a poorly soluble complex matrix for the analysis of the trace-element composition with high-resolution inductively-coupled plasma mass spectrometry was designed and tested. Analytical and method problems of the selection and preparation of samples are described and their solutions are proposed. The correctness of sample preparation was verified using analysis of standard rock samples.

Moscow University Geology Bulletin. 2017;72(1):56-62
pages 56-62 views

The source rocks in the southwestern part of the South Sakhalin Basin

Kiryukhina T., Bordunov S., Solov’eva A.

Resumo

In the southwestern part of the South Sakhalin Basin, the main source rocks are early Miocene clayey deposits of the Upper Due Suite, middle Miocene dark gray and black mudstone of the Kurasiy Suite, and, probably, black mudstone of the Bykov Suite of Late Cretaceous age.

Moscow University Geology Bulletin. 2017;72(1):63-74
pages 63-74 views

A geoelectrical survey of an area under construction near the Moscow–St. Petersburg highway

Kvon D., Shevnin V.

Resumo

The results of a geoelectrical survey of the Mshentsy area located in Tver oblast near the Moscow–St. Petersburg express road, which is under construction, are presented. In order to obtain information about the geological composition of the area and the processes that occur in it (karst and water flow zones ), we performed our measurements using the electrical resistivity imaging, self potential survey, water electrical conductivity and temperature measurements. Using petrophysical resistivity modeling of the rocks, taking the geoelectric data into account, we completed a lithology differentiation of the section and calculated the hydraulic conductivity values of the rocks. By interpreting this data, we found a wide distribution of fractured carbonates that compose the lower part of the section of the studied territory. The conclusion was drawn that the Mshentsy area belongs to the intense local karst zone.

Moscow University Geology Bulletin. 2017;72(1):75-79
pages 75-79 views

Brief Communications

The development of logging methods in solving hydrogeological problems at the Aleksandrovka research base

Nikulin B., Ostapchuk S., Hmelevskoy V.

Resumo

This paper presents the results of the development of a digital logging system and its implementation into everyday practice, at a well of Moscow State University. Complex data interpretation in relation to problems of hydrogeology is discussed. New developments, such as a video well-logging device and a highfrequency induction probe (HFIL) for plastic-cased wells, are used in the system in addition to the obligatory logging types (GL, RL, SP, CL, and temperature measurement).

Moscow University Geology Bulletin. 2017;72(1):80-83
pages 80-83 views

A study of the rate of gypsum leaching from the pore space of sandstones

Lebedev A.

Resumo

Experimental studies of the rate of gypsum leaching from the pore space in sandstone revealed a zone with higher dolomite content (due to dolomitization of calcite in the peripheral region of the block), with minimum values of gypsum content and maximum ones of total porosity. It is shown that leaching from rock blocks in the near-shore zone of the Kafirnigan (Kofarnihon) River is defined by two successive stages: (1) leaching of the dolomitization zone (the slowest) and (2) from the field with background values of dolomite and calcite (fast). The average value of the coefficient of diffusion for Ca2+ ions in the second region is higher by ~70% than in the first one.

Moscow University Geology Bulletin. 2017;72(1):84-86
pages 84-86 views

The geochemical patterns of rocks of the Bazhenov and Abalak formations (Western Siberia)

Bychkov A., Kalmykov G., Bugaev I., Balushkina N., Kalmykov A.

Resumo

The composition of rocks of the Bazhenov and Abalak formations in Western Siberia is described. Correlations of the concentrations of the major and minor components in rocks with the concentrations of minor elements and organic material are shown. Study of the concentration of minor elements allows us to determine the conditions of sedimentation: redox potential, hydrogen sulfide contamination, and the source of sedimentary material. The results show that rocks of the Bazhenov Formation were formed under the conditions of low fluxes of clastic material, a reduced environment, and a periodically occurring hydrogen sulfide mode.

Moscow University Geology Bulletin. 2017;72(1):87-94
pages 87-94 views

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