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Marly limestone, marble, and gabbro samples from the Kochumdek contact aureole are studied in order to estimate to which degree the spurrite-merwinite ( T = 750-900 °C) metamorphism at the site was isochemical. The 3 m wide zoned Kochumdek aureole is located at the contact between the Early Triassic trap intrusion of the Kuzmovka complex (νβT₁kz) and the overlying Llandovery marine marly limestones (S₁ln) of the lower Kochumdek subformation in the right side of the Kochumdek River (tributary of the Podkamennaya Tunguska, East Siberia). The Kochumdek rocks are remarkable by the lack of prominent skarn or vein mineralization in marbles and autometasomatism in gabbro. The samples have been analyzed for major, chalcophile, rare-earth, and high-field strength elements. The Kochumdek marbles and marly limestones share similarity in major-element patterns that record mixing of fine siliciclastic material with biogenic and chemogenic CaCO₃ components. The major-element chemistry of marly limestones has been controlled by the compositions of fine clastic material transported from the provenance (Trans-Angara part of the Yenisei Ridge) and by the deposition environment of the early Silurian marine basin. The contents of Cu, Ni, Co, V, Mo, Se, Cr, and U in marly limestones and marbles correspond to marine sediments deposited in a low-productive oxigenated environment. The Ni/Co, V/Cr, Cu/Zn, V/(V + Ni), and U/Th ratios in spurrite marbles at the intrusive contact remain within typical limestone ranges but differ from those in gabbro, which have higher V and Cu enrichment and moderate contents of Zn, Ni, and Co. Marly limestones and spurrite marbles show identical REE+Y patterns and average ΣREE contents. The major- and trace-element similarity between marbles and the protolith limestones, along with the absence of gabbro trace element fingerprints in the metamorphic rocks, indicate that the thermal metamorphism was nearly isochemical. The reactions occurred without any large-scale transport of major and trace elements across the sill/sediment boundary. The conditions were unfavorable for metasomatic alteration due to low fluid saturation of the Kochumdek intrusion and its structural setting, as well as to the lithological, mechanical, and thermal properties of the sediments.

Two cores of the Dulikha peat bog deposits, 4.0 and 5.2 m thick, were studied in detail. The reduction type of diagenesis has been established. Decomposition of the organic matter of the bog deposits begins already in the upper intervals of the section at the earliest stages of diagenesis. Microbiological studies of the peat bog revealed numerous organotrophic, ammonifying, nitrifying, and phosphate-mobilizing microorganisms as well as Fe-Ox and Mn-Ox microorganisms and showed the almost complete absence of sulfate-reducing bacteria (except for the lower intervals of the peat section). The processes of the nitrogen, phosphorus, and carbon cycles are more active than the sulfur cycle processes. The chemical composition of the bog water changes during diagenesis. The contents of HCO₃^-, NH₄⁺, PO₄^3-, NO₃^-, and TOC (Total organic carbon) increase in the peat bog section, which is the result of the destruction of organic matter, leading to the transition of the most mobile and labile components into the bog water. The results of physicochemical modeling show that the high content of organic matter significantly changes the chemical composition of the bog water. The enrichment of the latter in Cu, Zn, Sr, Ba, As, Si, Al, and Pb indicates a diagenetic transformation of the bog deposits. A change of oxidizing conditions by reducing ones in the peat bog leads to the reduction of oxidized Fe (III) and Mn (IV) forms to mobile Fe (II) and Mn (II) forms and their subsequent migration from the solid phase of deposits into the bog water. With depth, the reduced S (II) forms become predominant in the peat, which indicates more reducing environmental conditions. The concentration of SO₄^2- decreases in the pore water of the peat-underlying mineral deposits, which marks the beginning of sulfate reduction. This process, however, is very slow in the bog deposits because of the acid environmental conditions and the lower degree of transformation of organic matter.

More than a hundred lakes, groundwater, rivers, and precipitation of their catchments have been studied in Transbaikalia. The chemical composition of natural waters and the mineral composition of rocks and lacustrine bottom sediments have been analyzed. The isotope composition of waters, the isotope ratios in dissolved and deposited carbonates and in bacterial mats, and the content of heavy oxygen in the aluminosilicate fraction of bottom sediments and rocks in catchments have been determined. It is shown that all secondary minerals inherit the oxygen isotope composition of water, but their oxygen is isotopically much heavier than the water oxygen, because the water-rock interaction leads to the fractionation of oxygen and the transition of its heavy isotope into secondary carbonates and aluminosilicates. Bacterial mats using oxygen of carbon dioxide ions for their vital activity are also enriched in its heavy isotope. We have established that the water of soda lakes, being less saline than other lake waters, is more enriched in heavy oxygen isotope. Mineral analysis of lacustrine bottom sediments and material from sedimentation traps revealed chemogenic carbonates and secondary aluminosilicates. The performed thermodynamic calculations confirm their possible formation in lakes. It is shown that the lake water is in equilibrium not only with carbonates, clays, and hydromica but also with zeolites, and the most alkaline and mineralized water is in equilibrium with albite. The bottom sediments of soda lakes have a greater portion of clays and carbonates than those of fresh, chloride, and sulfate waters. The enrichment of salt lake waters with heavy isotopes is due not only to evaporation but also to the water-rock interaction. The contribution of aluminosilicate hydrolysis to oxygen fractionation is confirmed by the direct dependence of the “oxygen shift” value on pH, whose value is determined by the degree of the above interaction. We have established that the diversity of the chemical and isotope compositions of lake waters is due to their multifactorial formation related to the different degrees of lake water evaporation, the different mineralization of organic matter, and the different duration of the interaction of lake waters and groundwater with rocks.

The pattern of current crustal stress in central and southeastern Asia has been reconstructed from earthquake focal mechanisms by inversion Rebetsky’s method of cataclastic analysis. The inversion provides constraints on principal stress directions, as well as on relative magnitudes of maximum shear and effective isotropic pressure. The crust of the High Asian mountainous province is subject to horizontal extension or shear in plateaus (East and South Pamir and Tibet) and to horizontal compression or shear in mountain ranges. The relatively high horizontal compression in the ranges is apparently due more to denudation and exhumation than to the pressure from the Indian indentor. Denudation and removal of clastic material from the Himalayan slopes has been a key agent that may compensate for the N-S crust shortening in central Tibet and the W-E stretching in eastern Tibet. The current stress field of High Asia has been mainly controlled by vertical buoyancy forces that arise by thickening of lighter crust and detachment of heavier lithosphere.

We consider the application of MODIS satellite data to the analysis of the condition of oil-producing Arctic territories. The state of the vegetation cover of the hydrocarbon fields in the Purovsky region of Yamalo-Nenets Autonomous Okrug: East-Tarkosalinskoye, Vyngayakhinskoye and Tarasovskoye for the period 2013-2020 are studied. Based on Terra/MODIS satellite data and ArcGis geoinformation system, we calculated the average values of the vegetation index EVI (Enhanced Vegetation Index) for the areas under study. The anthropogenic load on the oil and gas complex is mapped, and the dynamics of the vegetation of the territories of oil and gas fields in the Yamalo-Nenets Autonomous Okrug is analyzed.

The problem of revealing relationships between atmospheric parameters measured with GNSS receivers and characteristics of convective processes based on monitoring data in Kazan for 2010-2020 is solved in the work. Coherence and synchrony of variations in the precipitation intensity and potentially available convective energy with variations in the zenith tropospheric delay are most often detected on time scales smaller than 4 hours, with the wavelet correlation level higher than 0.8 in most cases.

Method for studying the effect of the mass flow from the particle surface on the drag coefficient in a wide range of Reynolds numbers is suggested. For this, two experimental setups have been developed and used for the study of the effect of air injection from the surface of a solid perforated sphere on the drag coefficient at various values of the velocity of injection flow in the range of Reynolds numbers of the airflow around a particle from 133 to 9900. It is shown that the drag coefficient of the particle decreases with an increase in the velocity of the gas injected from the surface of a solid spherical particle. The empirical equation for calculating the drag coefficient of a solid sphere in the self-similar regime depending on the ratio of the gas injection velocity and the airflow velocity has been derived from the regression analysis.

Determining the spatial distribution of rare fungal species is critical to understanding the environmental factors that affect them. Maximum entropy (MaxEnt) spatial distribution modeling solves this problem by allowing inferences about species distribution and ecological resistance from occurrence data. Using this method, we mapped the current and potential geographic distribution of the rare species G. melanocephalum. To establish the regularities in the geographical distribution of the studied species in Siberia, we created its distribution models using Wordclim bioclimatic variables and the MaxEnt software. We modelled the species’ habitat suitability under current conditions (~1950-2000 AD) and in a future climate (2100 AD) based on 11 records of the species’ spatial distribution. Most localities of G. melanocephalum in Siberia are 200-500 meters above sea level. The optimal climatic conditions for G. melanocephalum in Siberia are typical of the habitats represented in the Kazakh forest-steppe, South Siberian forest-steppe, and hemiboreal forests of Western Siberia, in the zone of contact between the plains and foothills.

The Russian Far East has large areas of natural and semi-natural ecosystems. With the intensification of economic activity, it is necessary here a new look at the environmental policy with a focus on increasing the value of nature and its resources. The work consisted of converting a geo-botanical map into a habitat map. Habitats are presented in categories of “significance” and “value”. For all habitats are available floristic, ecological and biotope characteristics. The study area is a part of the Amur-Zeya plain. It is limited by geographical coordinates: 128°07 -128°23 north latitude and 51°25 -51°34 east longitude. It is part of the territory of advanced social and economic development “Svobodny”. The vegetation has been largely modified by humans. There are practically no native plant communities left here (pine, oak-pine, black birch-pine and black birch-oak-pine forests with larch). At present, secondary forest communities (oak, black birch, white birch) and their re-generative series grow here. The flora of the studied area includes 430 species of vascular plants. The list of fungi is represented by 267 species of macromycetes. The plant communities include 20 rare species of vascular plants listed in the Red Books of the Russian Federation (2008) and the Amur Region (2020). Plant communities are the main indicator of habitat, and their boundaries mark habitat boundaries. Habitats were divided into 5 groups: valuable, significant, moderately significant, insignificant and disturbed. In addition, the compliance of biotopes with the European habitat classification EUNIS was taken into account. Valuable habitats occupy 3 % of the total area on the habitat map. They include habitats of particular importance for the protection and the conservation of biological and landscape diversity. The significant habitats occupy 17 % of the total area. They include the Upper Amur forests (pine, oak and oak-black birch forests), mari, swamps and coastal aq-uatic vegetation, which have signs of standard natural communities. Moderately significant habitats account for 22 % of the territory. They belong also to natural communities, but have signs of disturbance. The insignificant habitats occupy 21 % of the total area. Species diversity decreases significantly here. Disturbed habitats occupy the largest areas (37 %).

It is reported about 10 new adventive species for the Novosibirsk region: ergasiophytes Berberis thunbergii, Brassica oleracea, Crataegus pinnatifida var. major, Eutrochium maculatum, Malus domestica, Prunus maackii, Sorghum drummondii, Tagetes erecta, and ergasioxenophyte Setaria italica. New localities of xenophytes Lolium multiflorum, Medicago sativa subsp. varia, Silene noctiflora and ergasiophytes Amelanchier humilis, Malus prunifolia, Mentha suaveolens, Physocarpus opulifolius, Tanacetum parthenium, which are rarely found in the Novosibirsk region, have been noted.