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The paper presents the results of studies of diamonds from Early Jurassic sediments making up the Nyurbinskoe buried placer of the Nakyn kimberlite field, unique in diamond reserves. The main task was to identify the patterns of diamond distribution in the deposits of the Dyakhtar strata (lower deposit) and the Ukugut Formation (upper deposit) within the placer. A comparative analysis of the typomorphic features of diamonds from the upper and lower deposits of the placer was carried out. Variations in the contents of crystals with certain properties that form the image of a diamond-bearing geologic object have been revealed. The zonal distribution of diamonds by characteristics in sedimentary deposits, regardless of their age, has been established. The properties of diamonds and their associations change within the placer, which is due to their redeposition during the Early Jurassic sedimentation.

The paper considers the geologic structure of the region and the current problems and prospects for the development of its energy potential and environmental safety. We provide grounds for the necessity of integrated projects aimed at studying the deep structure of the Caspian region as a single object by its five coastal states: Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan. The proposed Geokhazar project is aimed at obtaining the lacking parametric geological and geophysical information about the deep subsurface structure of the water area of a sedimentary basin in the unique intracontinental catchment of the Earth. The project provides for the development of a universal prospecting concept taking into account the emplacement and conservation of hydrocarbon fields under severe thermobaric conditions at great depths and the absence of regionally consistent drainage systems; the determination of the factors influencing the nature of long- and medium-frequency eustatic fluctuations in the Caspian Sea level; and the assessment of the energy (geothermal and hydrocarbon) resources of the deep subsurface in the Caspian, cis-Caucasian-Mangyshlak, and South Caspian oil and gas provinces.

Magnetic viscosity is one of the aftereffects inherent in geologic materials. This phenomenon consists in the time lag of changes in the magnetic characteristics of ferromagnetic materials relative to changes in the external magnetic field. Magnetic viscosity in rocks is associated mainly with the magnetization of superparamagnetic particles of ferrimagnetic minerals. In the transient electromagnetic method, magnetic viscosity is manifested as a slowly decreasing voltage induced in a receiving loop or, in some cases, as a nonmonotone transient voltage response. Eddy currents and viscous magnetization arise and decay independently of each other; therefore, the induction transient response measured with a fixed-geometry TEM array gives no way of finding the vertical distribution of magnetic viscosity. To find this distribution requires geometric soundings. At late times, the voltage induced in the receiving loop due to the magnetization decay is vastly larger than that induced by the eddy currents. Therefore, the contribution of magnetic viscosity to the total transient response limits the sounding depth of the transient electromagnetic method.

The geological study of the Mesozoic sections of the New Siberian Islands archipelago and Asian coastal sections of the Arctic Ocean plays a key role in tying the results of comprehensive studies with seismic data on the Laptev Sea shelf and the western part of the East Siberian Sea. Therefore, it is extremely important to improve the subdivision of the Triassic system of the New Siberian archipelago and to define the position of the system in the structure of the Laptev Sea shelf sedimentary basin. The results of our study were used to improve and refine the lithostratigraphic subdivision of the Triassic in the study area and to recognize a distinct interregional stratigraphic marker, i. e., the Czekanowski Formation (lower Olenekian). In terms of genetic, structural, and sedimentological features, the Triassic strata were grouped into two groups: the Reshetnikov Group (Induan-upper Ladinian) and the Svetlaya Group (Ladinian-Rhaetian), reflecting major stages of sedimentation. For the Triassic of the eastern Laptev Sea shelf and adjacent onshore areas, the facies zonation scheme has been developed and refined on a unified basis. Based on their structure, the Phanerozoic sections of the study area can be considered as a part of the intermediate structural stage of the Laptev Sea plate at the margins of the Siberian craton.

Numerous epithermal Au-Ag deposits and ore occurrences of the Chukchi Peninsula are localized in the Cretaceous Okhotsk-Chukotka (OCVB) continent-marginal and Late Jurassic-Early Cretaceous Oloi (OVB) island arc volcanic belts and in Early Cretaceous postcollisional volcanic troughs. Volcanotectonic depressions, calderas, and volcanic domes control the location of the deposits. The orebodies of the deposits are quartz-adularia veins, sometimes en-echelon ones forming extending vein zones, as well as isometric and linear stockworks. The auriferous veins of most deposits display complex breccia-crustification structures. The vein ores have rhythmically and colloform-banded structures, with a predominantly fine distribution of ore mineral grains, often with banded clusters of ore minerals (ginguro). Native gold is of low fineness; the dispersion of this index varies from low to high. Acanthite is widespread in the ores. Its highest contents are specific to deposits with the repeated redistribution of substance (Kupol, Corrida, and Valunistoe). Based on the results of mineralogical studies, most of the epithermal Au-Ag deposits of the Chukchi Peninsula can be assigned to the Se type. The ores of some deposits (Valunistoe, Dvoinoe, etc.) contain both Se and Te minerals. The telluride-richest sites of the Sentyabr’skoe and Televeem deposits are far from the main orebodies. Most of the Chukchi epithermal Au-Ag deposits have many common characteristics (low and moderate temperatures of fluids, low fluid salinity, domination of carbon dioxide over methane, etc.) typical of low-sulfidation deposits. The maximum temperatures and salinity are specific to fluids in the Central Chukchi sector of the OCVB and in the Baimka zone of the OVB, and the minimum ones are typical of fluids in the East Chukchi flank zone and inner zone of the OCVB. The average salinity of mineral-forming fluids in the inner zone of the OCVB is half as high as the salinity of fluids in the East Chukchi flank zone of this belt, although the sulfate content is higher. At the same time, the fluids in the inner zone of the OCVB are richer in carbon dioxide and bicarbonate ion than the fluids in the East Chukchi flank zone of this belt. The fluid inclusion data permit the Vesennee deposit (Baimka zone) to be regarded as an intermediate-sulfidation one and suggest the presence of epithermal high-sulfidation deposits in the inner zone of the OCVB.

The paper presents the U-Pb age of zircons and the geochemical and isotope characteristics of granitoids from the Kitoi block (Sharyzhalgai uplift, southwestern Siberian craton). The studied granitoids compose different-scale vein bodies. According to the structural relations among the rocks and their U-Pb zircon ages, there were three stages of early Precambrian granite formation: ~2.99, 2.54, and 1.88 Ga. The Neoarchean and Paleoproterozoic granites contain inherited zircons dated at ~2.97-3.00 Ga, which are close in age to magmatic zircons from the Mezoarchean granite-gneiss. The Kitoi granitoids of different ages show similar enrichment in SiO₂, K₂O, and incompatible trace elements. In trace element composition and crystallization temperatures the Mesoarchean granite-gneisses are similar to A-type granites, while the Neoarchean and Paleoproterozoic granitoids, to I-type ones. The inherited ~2.97-3.00 Ga zircons and narrow range of model Nd ages ( T _Nd(DM) = 3.0-3.3 Ga) indicate that the Neoarchean and Paleoproterozoic granitoids formed through the recycling of the Mesoarchean crust. The Neoarchean (~2.54 Ga) and Paleoproterozoic (~1.88 Ga) stages of granite emplacement in the northwest of the Kitoi block correlate with the formation of granitoids and high-temperature metamorphism in the Irkut block and the border zone between the two blocks. The subsynchronous granite formation and metamorphism (~2.54 Ga) give strong evidence that the amalgamation of the Kitoi and Irkut blocks resulted from collisional orogeny in the terminal Neoarchean.

We substantiate certain ideas concerning the key role of fluid-geodynamic processes in the evolvement of hydrocarbon accumulations at great depths in the Earth’s crust. The presented geodynamic model of oil and gas accumulation is based on updated ideas of the structure of the Earth’s tectosphere, which includes plate, preplate, and folded complexes. The model makes clearer the spatial scale of the organic-matter transformation into hydrocarbons of the oil series. In the bottom layers of the Earth’s crust, we predict the existence of a special stagnation type of water drive systems with the following distinguishing features: (a) different scales of manifestation, from local to regional; (b) a limited water exchange with the external environment; (c) the absence of persistent drainage horizons (beds and interbeds); (d) alignment of hydrodynamic potentials in terms of depths and laterals; (e) certain growth in the role of lithohydrochemical and organic chemical factors in the development of the void space of the fluid-host medium. In their inner space, systems with difficult water exchange can control the evolvement and preservation of autoclave hydrocarbon systems for a long time, the key feature of the autoclave systems being spatial coincidence (localization) of the processes of oil and gas generation and accumulation. We assume that in the settings of all-round compression, hydrodynamic instability, and no drainage, the position of productive zones must be controlled by foci of low pore (reservoir) pressures rather than local hypsometric highs. We present results of the prediction for the development of water drive stagnation systems in the subsalt deposits of the Caspian depression. A prediction for reservoir pressures was made for the sedimentary cover at great (and supergreat) depths. It can be regarded as a necessary component of prediction of oil and gas potential because it makes it possible to delineate new (previously unknown) commercial zones of hydrocarbon accumulation.

The general Vendian stratigraphic scale of Siberia, with the uncertain age of the Vendian base ranging from 600 to 630-640 Ma in most of recent publications, remains worse constrained than the Cambrian scale, in which the boundaries of epochs and stages have been well defined. However, the imperfect classical stratigraphic division has been compensated by data on the cyclicity of the Vendian-Cambrian sedimentary section. The Vendian stratigraphy of the Siberian Platform and the related deposition history with cycles of sedimentation and gaps, as well as the hierarchy of sedimentation processes, can be inferred from the succession of alternating clastic, carbonate, and salt units. The cyclicity of geologic processes and their recurrence are attributed to periodic oscillatory motions of the crust. The ranks of these motions correlate with the cyclicity of sedimentary strata, including regocyclites, nexocyclites, and halcyclites separated by gaps. Each Vendian long-period oscillatory motion begins with a regocyclite and ends with a regional-scale gap. The Cambrian section includes one pre-Mayan regional gap at the end of the early Cambrian long-period cycle. Cambrian regocyclites are composed of carbonate subformations and formations in the lower part and alternating salt and carbonate beds in the upper part.

The paper considers the regularities in the structure and conditions of formation of Domanik carbonaceous carbonate-siliceous productive deposits. They are shown to occur in the stratigraphic interval from middle Frasnian to upper Famennian. The highly persistent structure of their sections for many kilometers within specific sedimentation zones and the drastic changes in the structure at the boundaries of the zones are justified. Lithological classification of rocks is considered. Methods and results of combined paleontological, lithological, geochemical, and petrophysical core studies are presented, as well as interpretation of well logging data and seismic-survey materials used in the assessment of oil resources and identification of oil- and gas-promising zones and areas. The conducted studies have proved significant oil resources in the Domanik productive sequence; their extraction might compensate for the decline in oil production from conventional pools.

The aim of the work is to analyze the existing and used methods of direct molecular modeling of physical processes and phenomena. In particular, methods of molecular dynamics, Brownian dynamics, direct statistical Monte Carlo modeling, and stochastic molecular modeling are discussed. In all cases, the main features of these methods, the accuracy of modeling and development prospects are analyzed. Examples of solving original problems, in particular, modeling of gas transfer coefficients in the volume and nanochannels are considered.