Home – Home – Jornals – Advanced Search

This article presents a review of the results from a comprehensive study and dating of contourite deposits in the southwestern Atlantic. It focuses on identifying the sources and transport processes of sedimentary material in the context of Pliocene-Quaternary environmental and climatic changes. The primary emphasis is on research conducted by the Laboratory of Paleoceanography at the Shirshov Institute of Oceanology RAS in collaboration with colleagues over the past decade. The contourite systems examined include those on the continental slope of Argentinian Patagonia, the Santa Catarina and São Paulo plateaus, the Ioffe Drift, and the gravitite-contourite system at the base of São Tomé Seamount. The identification of these systems is based on a comprehensive set of seismoacoustic, lithological, and geochemical data, including variations in magnetic susceptibility. Diagnostic features that distinguish contourites from other types of bottom sediments are discussed. The age of the sediments is determined using biostratigraphy or oxygen isotope stratigraphy and corroborated by accelerator mass spectrometry radiocarbon dating for the last 50,000 years. It is demonstrated that the primary agent in the formation of these contourite systems is the erosional and depositional activity of bottom (along-slope) currents of Antarctic origin, which are a key component of the Atlantic meridional circulation and the global ocean conveyor belt. Consequently, contourite systems preserve a record of the geological and climatic history of the region. Among all the systems considered in this study, the Ioffe Drift contains the oldest sediments, which have accumulated over the last 3.2 Ma. This interval corresponds to the period of modern-type paleoceanographic variability that followed the closure of the Panama Seaway. For the other systems, the sediment cores characterize the glacial-interglacial stages of the Late Quaternary and the associated changes in sea level, climate, and bottom-water circulation.

We have conducted petrological, geochemical, and geochronological research on gabbro intrusions of the Utlyktash complex in the northern part of the West Magnitogorsk zone in the Southern Urals. The studied intrusions are confined to the wings of the Imangulovo syncline formed due to the syncollisional setting and to its surroundings. According to new LA-ICP-MS data, the age of the Uraz gabbro massif is 333 ± 3 Ma. The geochemical features and Nd-Sr isotopic composition of the Utlyktash complex indicate that a weakly depleted PM-type mantle is a source for gabbroids with subsequent significant magma fractionation and minor crustal assimilation (up to 6%). Thermodynamic modeling supports the fractionation model of a single parental melt from which all the studied gabbro bodies crystallized. The ID-TIMS and LA-ICP-MS U-Pb zircon dating (ranging from 0.44 to 2.73 Ga) has revealed the involvement of ancient continental crust and ophiolitic material from the Main Ural fault zone, along which the Magnitogorsk island-arc terrane was thrust onto the Laurussia paleomargin. The geological position of the Utlyktash complex and its geochemical correlation with basalts from the central part of the Magnitogorsk megazone suggest its formation during syncollisional rifting in the early Carboniferous, preceding the assembly of the Laurasia supercontinent.

Metasedimentary melange in the Mt. Sulu-Tyube area bears fine- and medium-grained eclogites, which are predominant within the Kokchetav subduction-collision zone (Kazakhstan), along with scarce porphyroblastic eclogites juxtaposed with rocks of the Zerenda Group. The assemblage of garnet cores ( X _Alm ≤ 0.59, X_Prp > 0.08) with epidote-clinozoisite ( X _Czo = 0.36-0.90), amphibole, ilmenite, titanite, and rutile and the prograde zoning of garnet suggest the nearly isothermal burial of rocks at 11.5-20.5 kbar and 535-570 °С. The growth of high-Mg garnet rims ( X _Prp ≤ 0.31) in paragenesis with omphacite ( X _Jd ≤ 0.35) marks the second stage with nearly isobaric heating up to 645 °С at 21.5 kbar and to 620-690 °С for some samples. Fine- and medium-grained eclogites with uniform structures and with weak zoning of garnet containing omphacite ( X _Jd = 0.20-0.40), rutile, and quartz inclusions formed during heating and limited pressure increase This article presents new data on ore mineral microinclusions and the ore element content of Kamchatka adakites associated with melting of oceanic lithosphere of varying ages in the transition zone from the Pacific Ocean to the Asian continent. Based on these data, hypotheses are made regarding the generation patterns of metalliferous adakites and their role in the formation of copper-gold-silver mineralization in the region. (580-660 °С and 16-19 kbar). Variations in equilibrium temperatures (620-730 °С) indicate their different positions within the subducted lithosphere. The eclogites are similar in signatures to MORB and correspond to low-Ti tholeiitic rocks, but the fine-grained rocks are depleted in Nb, Ta, and Eu and enriched in Th and are characterized by a radiogenic isotopic composition of Sr (⁸⁷Sr/⁸⁶Sr_i = 0.71181-0.72935) and moderately depleted Nd isotopes (ε_Nd(530) = 0.5-4.2), whereas porphyroblastic rocks rehydrated during exhumation show juvenile Nd-Sr signatures (⁸⁷Sr/⁸⁶Sr_i = 0.70212-0.70426, ε_Nd(530) = 6.6-7.2). The contrasting features of eclogites result from the subduction of the rift-related margin of the Kokchetav microcontinent or a more ancient continental structure including variably contaminated N-MORB- and E-MORB-type basites and from the involvement of oceanic or eroded Cambrian island arc rocks in the same process. The differences in the fluid regimes of subduction and exhumation were due to the proximity of a hydrated subduction channel for porphyroblastic eclogites and to the weak fluid permeability of continental lithosphere for fine- and medium-grained eclogites.

We present a thermodynamic model of the interaction between surface water and the flotation tailings of PGE-Cu-Ni sulfide ores from the studied ore district in the Krasnoyarsk Territory. The urgency of the study is determined by the need to assess the long-term stability of mineral assemblages. The aim of the study is to elucidate the regularities of transformation of mineral assemblages during long-term storage. The mineral and chemical compositions of samples from two pits and the chemical composition of aqueous extracts served as initial data. Calculations were carried out in the solid-water-gas system with varying Eh values to simulate different degrees of the system openness to atmospheric oxygen (standard P - T conditions, pCO_{2 gas} = 10^-3.5 atm). Based on the modeling results, it has been established that pyrrhotite remains stable under extremely reducing conditions ( pO_{2 gas} = 10^-79 atm), in which the dissociation of water into atomic oxygen and hydrogen is possible. In general, the obtained models reflect the transition from sulfide to oxide-silicate assemblages, accompanied by a decrease in the number of mineral phases as oxidation progresses. The modeled assemblages are consistent with the parageneses observed in the polished sections. It is shown that the material largely retains its primary mineralogical features even after decades of storage, which is explained by the high content of rock-forming minerals within a dense clay matrix that prevents penetration of oxygen and moisture in amounts sufficient for intense oxidation. The results obtained can be used in the development of technological schemes for the recovery of potentially valuable metals from flotation tailings of PGE-Cu-Ni sulfide ores.

This paper analyzes published data and brachiopod collections available to the authors to determine the systematic composition of brachiopods of the subphylum Rhynchonelliformea from the Cambrian formations of the Siberian Platform. To date, 50 species and 1 taxon identified to the genus level ( Finkelnburgia sp.) have been described. These belong to 15 genera, 10 families (family assignment for two genera remains unclear), and 5 classes. Cambrian brachiopods of the subphylum Rhynchonelliformea from the Siberian Platform can be divided into six associations, each characterized by a specific taxonomic composition, paleogeographic distribution, and stratigraphic range. The most representative brachiopods belong to the class Obolellata. Specimens of this class have been found in North America and Greenland, allowing for relatively confident correlation of Lower Cambrian deposits between North America and the Siberian Platform. The class Strophomenata is also widely distributed. However, of the ten Siberian species of the genus Billingsella Hall & Clarke, eight are endemic. Thus, the occurrences of these brachiopods can be effectively used for genus-level correlation of transitional strata between the Middle and Upper Cambrian. Representatives of other classes (Chileata, Kutorginata, and Rhynchonellata) have lower potential for interregional correlation, although some of them have been found in other regions of the world and can serve as additional tools for correlating distant sections.

In this paper, we propose a new chaotic one-way function ChaosKDF that combines the logistic map and cryptographically secure pseudo-random noise from the ChaCha20 generator. The irreversibility of the function is due to the exponential sensitivity to initial conditions and the addition of controlled noise, which leads to rapid degradation of information about the input. Based on information theory, we show that the conditional entropy grows no slower than a linear function of the input size n in bits with an increase in the number of iterations T. This provides a provable lower bound on the complexity of inversion: Ω(ε·2n·T). This makes the function computationally irreversible even for quantum adversaries. It is proven that for an input of at least 256 and an iteration number of 1000, the function is resistant to Grover’s attacks and quantum methods for analyzing dynamical systems, such as QPE and VQA, due to chaos and cryptographic noise. An analysis of side-channel vulnerabilities is performed, and protective measures are proposed, including a fixed number of iterations and energy consumption masking. A comparison with PRF (HMAC-based), HMAC-based KDF, streaming PRF and upgraded KDF demonstrates a balance between security, speed and energy efficiency. This makes it effective for resource-constrained environments such as IoT and PUF systems. The function generates a 56-bit output compatible with modern cryptographic standards. The work opens the way to physically motivated cryptographic primitives, where security is based on dynamic irreversibility rather than algebraic complexity.

The article presents a review of international publications on the problematics of Value-Based Management (VBM), based on a representative sample of 40 articles drawn from the total body of research published between 2000 and 2025. The main research directions are systematized into seven thematic blocks, with a summary and analysis of the key findings and results within each block. The review highlights the predominance of empirical studies and the absence of consensus on a number of issues. The paper also outlines the challenges faced by Russian companies in adapting the VBM concept to current conditions.

Due to the rapidly increasing turbulence of the external environment, Russia has once again come to the need to recreate its own self-sufficient national higher education system that will meet the needs of the Russian economy, the Russian mentality and focus on five-year training of specialists. The relevance of the research is determined by the need to understand and adapt the education system to the new labor market conditions and a rapidly changing society. The article presents the results of research conducted by the staff of the Department of National and Regional Economics and the Basic Department of Innovation and Industrial Policy Management at Plekhanov Russian University of Economics, concerning the role of the Russian educational system in the life of society, where it occupies a vast area of intertwining direct and indirect interests, processes, and actions of various parties: from an individual to the whole the population of the country; from individual enterprises, organizations, to the entire production; from the employee to the sphere of labor, the entire socio-economic complex of the country. In the light of recent reforms aimed at changing the structure of the bachelor’s, master’s and postgraduate levels of education, key changes are being considered, starting with the abandonment of the Bologna system and ending with new requirements for graduate training. The authors highlight both the historical component of the changes and current trends that will affect the future of higher education in order to create an effective educational environment that meets the requirements of the labor market.

The evolving of economic development strategies in the resource-dependent regions of the Siberian Federal District (SFD) necessitates economy diversification to mitigate risks associated with the depletion of natural resources. One promising avenue for such diversification is the development of high-tech and science-intensive industries. These sectors are characterized by high value-added production, reliance on environmentally sustainable technologies, and demand for highly skilled labor - factors that can significantly contribute to the socio-economic development of resource-dependent regions. However, the current level of development of high-tech and science-intensive industries in the SFD remains low. To foster their growth, a comprehensive system of state and regional support measures is required, including the implementation of government programs and regional development strategies, tax incentives, provision of preferential loans, and active promotion of clusters, technoparks, and technopolises.

This article provides an integrated description of the economic category “digital platform”, reflecting various levels of economic relations. At the essential level, digital platforms represent an emerging new economic order - the digital economy. In terms of their manifestations, digital platforms act as both a business model and innovative market mechanisms. The paper proposes that the emergence of a platform economy and the resulting increases in economic activity, efficiency, and the creation of new markets contribute to the country’s overall economic growth and the development of the socioeconomic system. The article focuses on digital platform markets and the specific features of their functioning. It is noted that the development of the platform economy requires effective antitrust regulation.