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The Central Asian Orogen was reactivated in the Cenozoic, which gave rise to mountain systems and sedimentary basins, strike-slip and thrust faults, ramps, and rift basins under the far-field effect of the India-Eurasia collision. Pre-Cenozoic structures, as well as the superposed Cenozoic deformation, are traceable in the gravity pattern. Analysis and correlation of stratigraphic, tectonic, geomorphological, and geophysical (resistivity and gravity) data from Gorny Altai and tectonic modeling on the basis of apatite fission-track thermochronology show that vertical motions have been the most active for the past 5 Ma. The uplift and subsidence produced, respectively, the Chulyshman and Ukok plateaus with high mountains around and the the Kurai-Chuya basin between them. Gravity data suggest the existence of Late Carboniferous, Jurassic, and Cretaceous rocks found in tectonic wedges around the basin at the base of its sedimentary fill.

This paper presents the thermal and hydrodynamic structure of the conduit of a thermochemical mantle plume based on the results of experimental and theoretical modeling of thermochemical plumes. The basic relations for determining the thermal power and diameter of plumes are given. Depending on the geodynamic setting of eruption, the following types of plumes are distinguished: plumes responsible for the formation of large igneous provinces (LIP); plumes with a mushroom-shaped head, responsible, in particular, for batholith formation; and plumes producing rift zones. Using geological data (extent of magmatism, age of igneous provinces, and sizes of igneous areas), we estimated the parameters of plumes in Siberia and its folded framing: mass flow rate of melt, thermal power, depth of origin, and diameters of plume conduits and heads. The plumes responsible for the formation of the Siberian LIP (relative thermal power Ka = 114.9) and the West Siberian rift system (Ka = 37.8 for each of the three plumes) originated at the core-mantle boundary and discharged in the presence of a refractory layer in the lithosphere. The Vilyui plume (Ka = 27.3) originated at the core-mantle boundary and caused the formation of a rift system in the absence of a refractory layer. The plumes that produced the Hangayn (Ka = 6.8) and Henteyn (Ka = 5.5) batholiths were initiated at the core-mantle boundary and had mushroom-shaped heads. The plumes responsible for the formation of rift zones might have originated at the 670 km discontinuity.

In this study we present data on the geologic setting, geochemical and isotopic compositions, timing and P - T conditions of metamorphism of Neoproterozoic terrigenous metasediments, and associated island-arc metavolcanics of the Predivinsk terrane of the Yenisei Ridge. Relatively immature terrigenous rocks were eroded from a local source which is associated with island-arc magmatic complexes. The geochronological constraints indicate that the terrigenous rocks were eroded from juvenile crustal sources represented primarily by magmatic rocks, which are similar to those of the Predivinsk terrane. This is supported by a similar range of model ages, positive εNd values of terrigenous and magmatic rocks, and correspondence between the concordant ages of detrital zircons from metasedimentary rocks (610-640 Ma) and the U-Pb ages of zircons from rhyolites (ca. 620-640 Ma) from two suites within different sequences. The P-T conditions for volcanosedimentary rocks of the Predivinsk terrane correspond to the epidote-amphibolite facies and the transition from epidote-amphibolite to amphibolite facies. The most likely age of metamorphism due to Vendian accretion/collision events is given by Ar-Ar dates of 600-610 Ma.

We performed geological, geochronological, and isotope-geochemical studies of two tectonized-granite bodies intruding the rocks of the lower plate of the Bezymyannyi metamorphic-core complex (MCC) (western Transbaikalia). The U-Pb zircon age of sheared granites sampled on the periphery of the Bezymyannyi MCC near the detachment zone is 202 ± 2 Ma (LA-ICP-MS). The U-Pb dating (SHRIMP-II) of zircon grains from gneissic granite intruding the rocks of the lower plate in the central zone of the Bezymyannyi MCC has yielded an age of 165 ± 2 Ma. The sheared granites dated at 202 Ma (Late Triassic) have low contents of Nb and Ta and high contents of Sr and Ba, probably inherited from magmatic subduction-related sources. These granites are characterized by εNd(T) = -3.7, which, along with the high contents of K2O and medium contents of Th, testifies to the presence of continental-crust material in their source. Thus, they formed, most likely, from a mixed mantle-crust source. The studied granites, like other Triassic igneous rocks in Transbaikalia, might have originated in the suprasubduction setting during the evolution of the active continental margin of the Siberian continent. The gneissic granites dated at 165 Ma (Middle Jurassic) have high contents of K2O, Rb, and Th, are depleted in Nb, and are characterized by εNd(T) = 0 and a negative Eu anomaly on the REE patterns. They formed, most likely, from an intermediate-felsic crustal source. These Middle Jurassic granites, like other small Jurassic granitoid massifs spatially associated with MCCs in western Transbaikalia, intruded in the western part of the Mongol-Okhotsk Ocean after its closure, during the change of the subduction regime for the collisional one. The studied Late Triassic granites of the Bezymyannyi MCC cannot be associated with MCCs in Transbaikalia because their intrusion was related to the subduction of the oceanic plate of the Mongol-Okhotsk Ocean beneath the Siberian continent. The Middle Jurassic granites of the Bezymyannyi MCC, together with other small Jurassic granitoid massifs, can be classified as prekinematic intrusions formed earlier than MCCs in western Transbaikalia. However, it is unlikely that their intrusion caused a large-scaled crustal extension in Transbaikalia.

In this study we propose a new classification of rocks of the Bazhenov Formation based on the proportions of four principal components (siliceous, clay, and carbonate minerals and organic matter (kerogen)) of mostly biochemogenic and, to a lesser extent, allothigenic origin. The classification is based on the results of mineralogical and chemical analyses of more than 400 core samples from 15 wells drilled within the Bazhenov Formation, West Siberian petroleum basin. Four major classes of rocks, divided into 16 subclasses, have been recognized. The terms mixtite and kerogen-rich rock are introduced. Mixtites (biochemogenic mixtites) are defined as a class of rocks containing less than 50% of each component, including kerogen. It was shown that the most common rocks of the Bazhenov Formation are siliceous-argillaceous, kerogen-siliceous, and kerogen-argillaceous-siliceous mixtites and kerogen silicites, which together account for ~65% of all samples analyzed. The proposed approach can be used to study organic-rich black shales in different sedimentary basins worldwide.

Analysis of geological and geophysical data on the boundary zones between the Eurasian plate and other plates shows poor knowledge of the deep structure of the region. This information data will help to refine the position of the plate boundaries and the structure of the Earth’s crust and mantle. We present data on the seismicity and deep structure along the deep seismic sounding (DSS) profile running across the boundary between the Eurasian and Okhotsk plates. A comprehensive analysis of the DSS materials and seismic data shows a significant expression of this boundary zone both in the deep Earth’s crust structures and in the Moho. A zone of anomalous seismicity and deep structure extends along the DSS profile for several hundred kilometers. We have refined the position of the main boundary between the Eurasian and Okhotsk plates, which passes approximately along 144ºE.

A hypersingular integral on the interval of integration with the weight function is considered. We prove the spectral ratios for hypersingular integrals on [-1, 1]. The quadrature formulas for certain integrals with the weight function are constructed. The estimation error is presented.

On non-matching grids discrete analogue conjugate-operator models of heat conduction, keeping the structure of the original model are constructed. Numerical experiments show that the difference scheme converges with second order of accuracy for the case of discontinuous parameters of the medium in the Fourier law and non-uniform grids.

It is shown that due to the periodic changes in metacentric heights of a pontoon on the astir surface of liquids in the sump of an open coal mine, the pontoon is capable to produce parametric pitching, both in the longitudinal and in the transverse directions. The equation, describing parametric pitching, is transformed to the Mathieu equation, whose factors depend both on the own frequencies and the pontoon floatability features on «calm water», and on the frequency of fluctuation of a liquid, which, in turn, is defined by the sump size. The installed regularities between parameters, characterizing parametric pitching in the longitudinal and transverse directions, and areas of its instability are revealed.

We give a complete description of the set of matrix pairs such that T is a real Toeplitz matrix, H is a real Hankel matrix, and TH = HT.