No 4 (2015)
5-13 320
Abstract
Within the author's rotational concept a brief review of geodynamic movements of the block rotating nonlinear geomedium is done. Such geodynamic movements appear to be consistent with the volcanic process. It is shown that the magma chambers that fed the strong eruption of the planet over the last million years, have a constant thickness of about 0.5 km, which does not depend on the time and type of volcanic eruption, or on its location. The new model of the magma chamber is described. The model is based on the concepts of plastic flow of “solid” substance along the block boundaries, its “overheating” above the melting point and the elastic strain with energy of 1015 J/km3 of superheated rock formed around “solid magma” chamber. Within the rotational concepts such elastic stresses can explained the migration of volcanic activity itself and its interaction with seismicity and tectonics. Magma chambers with such properties don’t depend on the volcanic process and, in fact, are a reflection of a well-defined geodynamic condition of the Earth's crust. Since the set of magma chambers beneath the volcanic belt forms a unified thin layer, properties of these chambers can be extended to the entire Earth's crust. Within such ideas the hypothesis which explains the Moho properties by the phase transition from a state of “block crust with shear flows of substance along the block boundaries” to the state of “non-block upper mantle with volume substance flow” is proved.
14-23 679
Abstract
Analysis of available published geological-geophysical data by the new seismic data CDP and drilling allowed making a conclusion that there are two groups spatially separated salt dome structures within the Chu-Sarysu basin. Age of rocks in the cores of the Permian salt structures in the north-west and the Devonian in the southeast, and not only the Devonian as previously thought. The shear-thrust movements are the decisive role in the development history of the Permian salt domes in northwestern Chu-Sarysu basin.
24-42 362
Abstract
We considered the issues of the structure, material composition and secondary changes of Karuyarvinskaya suite rocks of riphean Kildin series at Peninsula Srednii. There is the characteristic of stromatolithic biostromes Stratifera aff. flexurata Kom., which was first discovered within very narrow fault zone of the well-known Riphean stromatolithic (reefogenic) formation. It is framing the East-European Epikarelian platform from the east and the north-east. We offered the correlation scheme of Peninsula Srednii Riphean complexes with Riphean deposits of Srednii Timan and Southern Urals.
43-61 501
Abstract
Several reef-building systems occurred during Cambrian-Devonian on the Urals and adjacent regions of the East-European Platform. The first phase was manifested in the Lower Cambrian within a limited area of the western slope of the Urals. The next stage occured on the western slope of Urals during Early to Middle Devonian as a result of Caledonian orogeny. This reef complex is traced on the western slope of the Urals from the Ural River latitude on the south to Barents Sea on the north. Late Devonian bioherms on the territory of the East-European Platform are distributed over a wide area from the Western Urals to the Volga basin. On the east slope of the Urals and in West Siberia bioherms are attributed to marginal structures of depressions.
62-72 346
Abstract
The Upper Visean-Serpukhovian deep-water shelf succession is described in the Subpolar Urals. Turbidite model of the sequence forming and direction of the carbonate material transport are proposed. The bioherm and shoal facial belt of the shelf margin is supposed as a main source of the material.
73-86 355
Abstract
The medium-scale gravity survey over the Ulaanbaatar area (Central Mongolia) has yielded the Bouguer gravity anomaly map. Based on interpretation of these data, 3D models have been built for large density inhomogeneities in the Earth’s crust - Ulaanbaatar (Tola) depression and Bogdo granite massif. It has been identified that the basement of the depression has a block structure and complicated by two basins: western and central (Selbe) The sediment thickness averages about 150 m in the western basin and may reach 300 m in the Selbe. The thickness of granitoids in the Bogdo massif reaches 4.5 km, the area of its projection on the earth's surface is twice the area of the exits. The data on the form and dimensions of these density inhomogeneities may be used in engineering seismology to update seismic hazard estimates for the town of Ulaanbaatar and to conclude about the prospects for metallogenic specialization of granitoids whose features concerning some minerals are related to peculiar massif form and identified by geological-geophysical and geochemical studies.
SHORT COMMUNICATIONS
87-92 370
Abstract
The massive and disseminated gold-copper-cobalt sulfide ores (Karasya Gora deposit) are restricted to the body of metahyperbasites of anthophyllite and tremolite-anthophyllite composition. In the history of evolution of the Sysert’ metamorphic complex anthophyllite rocks are associated with processes of a granitization and appeared twice: during the Paleozoic regional silica-acid metasomatism, synchronous with a plagiogranitization, and during a local Late Paleozoic silica-acid metasomatism, synchronous with potassium granite magmatism. The age 294-306 Ma of the formation of the gold-sulfide ores in anthophyllite rocks is established using the U-Pb method of chemical dating of uraninite crystals and are shown (average value 300 ± 3 Ma). The obtained value of uraninite’s age indicates that the fluid produced at the regressive stage of a plagiogranitization which finished the process of the silica-acid metasomatism of the ultramafic rocks, participated in the gold-sulfide ore formation.
93-98 338
Abstract
This is represents the results of dating of the Nikolsky granite massif (by Ar-Ar and Rb-Sr methods) situated within the Ufaley block which is the complicate heterogeneous structure in the accretion zone between the Uralian orogen and the East European platform in the Sout-Middle Urals region. The age of granites ranges from 570 to 30 Ma and corresponds to a final stages of the Timanian tectonic-thermal activity fixing by the granite generation and metamorphic events in the Cis-Polar, Polar and Southern Urals. The setting of the age of the Nickolsky granite extends our imaginations about the scale of the Vend-Cambrian events on the western slope of the Urals, and intrusion of such granites, probably, was connected with movements on preexisting faults which were formed during an ancient continental rifting stage.
ISSN 1681-9004 (Print)
ISSN 2500-302X (Online)
ISSN 2500-302X (Online)