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The Tuvinian trough is one of the large grabens of the rift system formed in the Devonian-Carboniferous in the eastern part of the Altai-Sayan fold area. Based on the results of comprehensive studies, the age was refined, and the geochemical features of igneous rocks formed during two stages of tectonic and magmatic activity within the Tuvinian trough were studied. In the Early Devonian (397 Ma, Emsian), at the stage of the initiation of the Tuvinian trough in the stretching setting, the volcanic and subvolcanic rocks of the Kendei Formation formed, which make a bimodal series. The Early Devonian igneous rocks of mafic composition have geochemical features of both intraplate (low values of Mg#, high contents of K₂O (up to 2.9 wt. %) and TiO₂ (up to 2.2 wt. %), and enrichment in LREE relative to HREE) and suprasubductional (enrichment in Pb and Sr and depletion in Ta and Nb) formations and are characterized by high values of εNd(T) (+5.9 to +8.0). They are assumed to have formed from a mixed source including the depleted mantle and components modified by subduction. The Early Devonian felsic volcanic rocks, which are the extreme member of the bimodal sequence, also combine the geochemical features of rocks of intraplate (high Fe and low Sr, P, and Ti contents, Zr and Hf enrichment) and island arc (Ta and Nb depletion) origin. These rocks with εNd(T) values from +4.0 to +7.0 resulted from the melting of a heterogeneous source corresponding in composition to the lower continental crust. In the Middle Devonian-early Carboniferous (390-350 Ma), the Tuvinian rift trough evolved to a mature stage, at which the mafic rocks of the Torgalyk Complex were intruded. The Middle Devonian-early Carboniferous mafic rocks are similar in isotope and geochemical characteristics, including the Nd isotope composition (εNd(T) = +6.7), to the Early Devonian formations. In contrast to the Early Devonian rocks, the magmas for the Middle Devonian-early Carboniferous mafic rocks were generated from a relatively homogeneous mantle source without significant metasomatic transformations, the features of which are better manifested in the Kendei rocks.

Kuvaevite ((Ir,Rh)₅(Ni,Fe,Cu)₁₀S₁₆) forms small grains (up to 20 µm across) in globular inclusions hosted by grains of Os-Ir-(Ru) alloys (up to 0.5 mm) in ore occurrences along the Ko River in the Sisim placer zone, Eastern Sayans. Rh-bearing pentlandite or oberthürite (or both), the minerals of the laurite-erlichmanite series and Pt-(Pd)-Fe alloys are the main associated minerals. Kuvaevite is gray to brownish gray in color in reflected light. Its bireflectance is weak to absent. It is slightly pleochroic in gray to light brown shades, and slightly anisotropic, from gray to light yellow shades. Its calculated density is 6.37 g/cm³. According to results of microprobe analyses ( n = 3) carried out using wavelength-dispersive spectrometry, WDS, the composition of kuvaevite is: Cu 5.94 (4.39-6.89), Ni 13.95 (13.80-14.24), Fe 10.95 (10.18-11.97), Co 0.07 (0.06-0.10), Ir 32.38 (32.19-32.73), Rh 7.27 (7.22-7.31), Pt 1.91 (1.67-2.06), Os 0.05 (0-0.09), Ru 0.05 (0.04-0.05), S 27.06 (26.77-27.41), total 99.63 wt.%. The empirical formulae calculated using the mean results of analyses are: (Ir_3.22Rh_1.35Pt_0.19Ru_0.01Os_0.01)_Σ4.78 (Ni_4.54Fe_3.75Cu_1.79Co_0.02)_Σ10.10S_16.13 (WDS) and (Ir_3.23Rh_1.43Pt_0.25)_Σ4.91 (Ni_4.49Fe_3.57Cu_1.86Co_0.06)_Σ9.98S_16.11 (SEM/EDS; n = 56). These are based on a total of 31 atoms according to structural data obtained for torryweiserite, the rhodium-dominant analogue. Kuvaevite forms solid-solution series with torryweiserite, tamuraite and ferrotorryweiserite, all these being isostructural. The symmetry of kuvaevite was determined using the synchrotron Laue microdiffraction; the results are in good agreement with the trigonal crystal system and give the following unit-cell parameters: a = 7.079(5) Å, c = 34.344(12) Å, V = 1490(2) ų; Z = 3. The ratio c/a is 4.852. The probable space-group, R3m (#166), is based on structural results for torryweiserite. The strongest eight reflections in the X-ray diffraction pattern derived from the microdiffraction study [d in Å(hkl) (I)], are the following: 3.0530(20 1)(43), 3.0103(2 1 6)(100), 2.9962(1010) (53), 2.7991(205)(50), 2.4946(208)(31), 1.9208(3 1 10)(41), 1.7697(4 2 0)(73), 1.7582(20 16)(66). The results of the electron backscatter diffraction study (EBSD) of two kuvaevite crystals are well-indexed based on the R3m space group. Kuvaevite and related sulfides significantly vary in composition in the Ko River placer, in the entire Sisim zone, and in some other ore occurrences worldwide. Associations of platinum-group minerals observed in ore occurrences at Ko River and in the Sisim zone seem to be genetically related to bedrock zones of chromite-bearing ultramafic rocks (serpentinites) of the Lysanskiy complex. Kuvaevite and other minerals present in the polymineralic inclusions, hosted by Os-Ir-(Ru) alloys, formed from droplets of residual melt. This melt accumulated the “incompatible” elements, which could not be incorporated into the structure of the host alloy, including lithophile elements, chalcogens (S, Te), semimetals (As, Sb, Bi), base metals (Fe, Ni, Cu), as well as relatively low-temperature PGE species (Pt, Pd) and Rh. There are local data on metastable crystallization and undercooling of the silicate melt, as well as effective differentiation and fractionation of S and ore components during the crystallization of these inclusions. Kuvaevite is named after O.M. Kuvaev (1934-1975), a prominent geologist, geophysicist and writer.

The post-Cenomanian sedimentary sequence of the East Messo-Yakha oil and gas field in the southern Gydan Peninsula comprises twelve lithological units (beds) correlated to Upper Cretaceous, Paleogene, and Quaternary regional stratigraphic stages and formations. The facies of the sedimentary units are constrained from lithology and microfossils. The stratigraphic division is based on bio-stratigraphy (fauna and spore-pollen assemblages), paleomagnetism, and geochronology (quartz and feldspar grains dated by optically stimulated luminescence). The deposition record is interrupted by six large stratigraphic unconformities. The obtained data provide new insights into the Late Cretaceous, Paleogene, and Quaternary paleogeography of the area.

In August 2019, four descending (gravity) springs in the Inya River valley were sampled during the field works conducted within the study of low-radon waters of the Novosibirsk urban agglomeration in the area lying away from known granite massifs. Laboratory analyses have revealed enhanced radon activity concentrations (from 5 to 149 Bq/dm³). It has been established that these waters are fresh, of HCO₃ Mg-Ca chemical composition, and have a TDS value of 413 to 548 mg/dm³ and a silicon content of 4.1-8.6 mg/dm³. They are characterized by neutral to slightly alkaline pH (7.1-8.4) and oxidizing geochemical conditions with Eh from +205.3 to +231.8 mV and O_{2 dissolv.} = 6.24-12.26 mg/dm³. The revealed predominance of SO₄^2- over Cl^- concentrations in the waters of the study area was probably due to the presence of sulfides in the water-bearing sediments, in particular, pyrite in the surface sediments. More than tenfold proportional excess of Ca concentrations over Si in the Inskie spring waters indicates the predominantly carbonate composition of the water-bearing sediments. The gross α-activity of waters is 3-4 mBq/dm³, and gross β-activity is 11-15 mBq/dm³. Natural radionuclides are found in the spring waters within the following limits (mg/dm³): ²³⁸U, from 2.83 · 10^-3 to 4.13 · 10^-3; ²³²Th, from 2.39 · 10^-6 to 1.16 · 10^-5, and ²²⁶Ra, from 3.83 · 10^-10 to 4.93 · 10^-10. The value of the ²³²Th/²³⁸U ratio for the waters ranges from 5.79 · 10^-4 to 3.61 · 10^-3, as a result of the oxidative geochemical migration-arresting capability of thorium. The uranium isotope ratio (γ) ²³⁴U/²³⁸U varies from 2.6 to 3.2 for the waters, with the uranium isotope activity determined as 117-124 mBq/dm³ for ²³⁴U and 38-48 mBq/dm³ for ²³⁸U. This indicates shallow circulation of the studied waters as compared with those of the Svyatoi spring in Verkh-Tula Village, for which γ = 1.3; the ²³⁴U activity, 147 mBq/dm³; and the ²³⁸U activity, 115 mBq/dm³. By isotopic composition, the origin of the spring waters is assigned to the infiltration type, and they are characterized by relatively narrow distribution of δ¹⁸O (from -17.5 to -16.7‰) and δD (from -128.4 to -126.2‰) values. The δ¹³C_DIC values are from -10.3 and -10.9‰ in springs 3 and 2 and become lighter (-11.2 and -12.1‰) in springs 1 and 4, respectively. This is due to significant participation of surface waters in the recharge mechanism of springs 1 and 4, which is also consistent with the δ¹⁸O and δD data and ¹⁴C dating. The estimated age of water-dissolved carbon is 1478 ± 81 years for the waters of spring 3 (the oldest), while it is found to be only 651 ± 53 years for spring 4 and is estimated as modern for spring 1. The reported decline in the age of water-dissolved carbon down to recent age is indicative of increased contribution of surface water to the spring recharge area. The C and O isotope compositions of calcite of the host aquifer rocks are characterized by close values for most of the samples: δ¹³С varies within narrow limits (from -3.1 to -2.7‰), and δ¹⁸О varies from 17.2 to 18.4‰. The isotopic composition becoming lighter for carbon (up to -11.0‰) and oxygen (up to 13.9‰) was noted for weathered schist samples. Results of the carbon isotope analysis of rock samples, their organic component, and water indicate an active isotopic exchange in the water-rock-organic matter system.

The current stress state of the Earth’s crust on the territory of Uzbekistan is studied using algorithms from the cataclastic analysis of displacements (CAD) with the application of a combined catalog of earthquake source mechanisms. The axis of maximum compression is nearly horizontal and orthogonal to the strike of tectonic structures for the larger part of the area under study, and the angle of penetration of the axis of minimum compression varies greatly for different parts of the territory. The areal distribution of the Lode-Nadai coefficient indicates the predominance of a stress state close to pure shift for the area under study. Without differentiation of the seismically active bed by depth, almost the entire territory of Uzbekistan is characterized by a geodynamic stress state corresponding to horizontal compression. There are significant differences in the stress state parameters for different deep beds of the Earth’s crust. With account for the representative recording periods of seismic events of different energy levels, the earthquake recurrence parameters for the entire territory as a whole and large seismically active zones are determined. It has been established that the epicenters of strong earthquakes recorded since the historical time are grouped in compact areas with linear dimensions of 50-80 km. The tectonophysical interpretation of the selected areas is given within the framework of the CAD, in which it is noted that strong earthquakes occur mainly in areas of lower effective confining pressure and maximum tangent stresses. This is due to the fact that the values of friction forces at faults in such areas are low, which creates the most favorable conditions for large-scale destruction. According to the results of the reconstruction of the natural stresses of the CAD, such areas on the territory of Uzbekistan are identified within faults and flexural-fault zones in South Fergana and North Fergana, as well as in the Gazli region. The current seismological situation in the selected areas of long-term forecast is estimated using a set of prognostic parameters of the seismic regime, and a map of the areas of expected seismic activity is compiled. The analysis of previous forecast maps developed within the framework of the presented approach shows high value in their information.

The article is dedicated to studying the phenomenon of decay (loss of relevance) of strategic documents at the regional and municipal levels in Russia. By analyzing major news sources, we show that Russian strategic planning documents are static, “sluggish," and unable to respond to rapid changes in the social, economic, political, and cultural environment (as in the case of the coronaviruspandemic). This leads to their rapid semantic degradation, the loss of their connection with current socio-economic challenges. It has been revealed that the duration of decay time differs among regions and municipalities, as well as among individual cities and regions, depending on local conditions. According to our estimates, a regional strategy decays and fully dies out within two to three years, while the same period is one to one and a half years for a municipal one, which is, in fact, equal to the time these strategies are drafted.

The article presents an analysis of the state and trends in the development of interregional relations of the Republic of Belarus with the regions of the Russian Federation and China. It elaborates proposals on how to form an institutional framework for deepening interregional interactions within the Union State of Belarus and Russia, which includes establishing legal support institutions, expanding the powers of the Union State of Belarus and Russia’s governing bodies, local self-government, coordination, and developing integration environment. The article highlights the main provisions of the draft Strategy for the Development of Interregional Cooperation Between Belarus and the People's Republic of China that contains recommendations for increasing the positions of non-potash commodity exports, taking into account such factors as the demand, price competitiveness of Belarusian products, expanding the export positions of high-tech products and goods of regional specialization, partnering with SMEs, cluster structures, etc. The format of regional associations has been defined as a practically untapped reserve for the growth of interregional relations between Belarus, Russia, and China. The main drivers that build up the capacity for interregional cooperation in the context of regional integration are considered to be as follows: creating an information and analytical database on the status of and current changes in the foreign economic strategies of the regions of China and the EAEU countries; using the potential of the digital logistics corridors project in the EAEU; establishing trade and marketing alliances; working out a joint action plan to include megalopolises and agglomerations, innovation zones, industrial parks, and border areas in interregional interactions.

For decades, transforming the economy of Kuzbass (Kemerovo Oblast) has been presented in the region’s strategic planning documents as the most important method to ensure accelerated economic growth. The authors of this article prove that, unfortunately, there have been virtually no qualitative changes in the Kuzbass economy over the past twenty years and give reasons why this has occurred. Kuzbass is currently facing the difficult task of choosing a long-term development model. On the one hand, despite the existing internal challenges and risks, the government is targeting businesses and society at accelerated growth, relying primarily on opportunities to increase coal production and advance SMEs. On the other hand, a critical mass of subjective and objective circumstances is gradually accumulating in Kuzbass, which in the medium term may radically change the situation, and the transformation of its economy will be the only possible model of economic growth. The main problem is the prospect of coal being displaced from the global economy under the pressure of decarbonization trend. Russia lacks a generally recognized systematic approach to the structural reorganization of coal-producing regions under the decarbonization policy. Having studied some relevant practices abroad, we offer an original concept of transforming the Kuzbass economy on the principles ofjust transition, used by the European Union. The prerequisite for its successful implementation must be a dialogue between the authorities, businesses, and society in elaborating and coordinating the corridors of the region’s future development.

This article calculates the true savings of single-industry towns in Siberia and the Far East between 2011 and 2018. We propose a new classification of single-industry towns based on their results, considering sectoral specialization and true savings levels. Our viewpoint is that to make effective management decisions with regard to each single-industry town, it is necessary to organize field monitoring and investigation. The article suggests a possible structure of the field team report. The author’s proposals on differentiated lines of state policy for each group of single-industry towns, which take into account the level of true savings in a single-industry town, sectoral specifics, distance to a major city, and strategic importance for the Russian Federation, have become the result of this research cycle.

The article considers certain guidelines for establishing a Siberian scientific school of regional and municipal government, including research on the issues of regional reproduction, regional economic independence, regional preplanning, a program-target approach to managing the regional economy, comprehensive regional planning, the study of regional competitiveness, patterns of interaction mechanism between economic entities in the territory, and the objective conditions and principles of social and economic management in a region. By analyzing and summarizing the institutional aspects involved in the activities of state and municipal governments, schemes and procedures of regional planning and forecasting, the paper has identified the features of modern management structure and proposed directions to form an integral system of regional and municipal development management, as well as core elements of the state and municipal management mechanism under the new terms of Russia’s socio-economic development. We review the basic provisions contained in the concept of regional and municipal government under present-day conditions, including consideration of economic interests and contradictions in the development of regional economy, interactions between state and market structures, working out an institutional system to manage regional development, evaluation of the effectiveness of regional economic management, establishing a socio-economic environment to ensure the competitiveness of the urban and regional economies through increased investment attractiveness and effective use of budgetary funds, which will create prerequisites for the transition to a management model enables the substantial economic independence of municipalities and enhances their role in the economic strategy of regional development.