bluuebunny/crossref_metadata_2025 huggingface dataset:
NEOSTRUCTURAL ZONING OF THE RUSSIAN PART OF THE KAZBEK SEGMENT OF THE GREATER CAUCASUS MEGAVAULT
Authors: Nesmeyanov S. A. , Nikitin M. Yu. , Voeikova O. A. , Komarevskaya M. N.
Published: April 2024

The Kazbek segment differs from the adjacent Central and Eastern segments of the Greater Caucasus megavault by the relative narrowing of the main zones and their latitudinal orientation. The main units of the segment comprise the zones of central elevations and northern and southern flanks. The application of orotectonic method allowed us to subdivide these zones into a number of regional and local late-stage structures separated by active faults. There are three suture zones. The pattern block structures are separated mainly by downthrows. The original data obtained, which are not presented in standard materials on geological survey, are useful for construction design and in solving geoecological tasks.
EVALUATION OF NATURAL RISK CHANGES WITHIN EROSIONAL THERMOKARST PLAINS UNDER THE IMPACT OF CLIMATIC TRENDS
Authors: Viktorov A. S. , Kapralova V. N. , Arkhipova M. V. , Orlov T. V.
Published: April 2024

The relevance of assessing risk to engineering structures from geohazards is determined by changing natural conditions in the permafrost zone. Risk assessment by statistical methods directly is accompanied by certain difficulties. Accumulation of statistics requires a significant amount of time, and this time is often comparable to the time of engineering structure operation. The most difficult stage of risk assessment is the assessment of the probability of damage to engineering structures caused by a hazardous geological process. The aim of the study was to substantiate the method for solving this problem on the territory of thermokarst plains with fluvial erosion for linear engineering structures using the methods of mathematical landscape morphology. Mathematical landscape morphology allows us to proceed to the quantitative risk assessment. The first step of applying methods of mathematical landscape morphology is to divide the area into homogenous by the process development sections. The method is based on the model that was proposed by the authors for the development of the morphological structure of thermokarst plains with fluvial erosion under conditions of an asynchronous start, which is realized according to empirical verification in most of cases. The model of risk assessment was applied to 4 key areas located under different physico-geographical conditions, but having morphological homogeneity. Using satellite images of different periods, the delineation of thermokarst lakes and khasyreys was carried out. The average density of the number of lesions in different areas varies from 0.00026 year–1 to 0.00104 year–1, and there is no clear trend of change with time. According to quantitative experimental data, there has been a site-differentiated change in the risk of damage to linear structures within the thermokarst plains with fluvial erosion over the past few decades (46–56 years). The probability of damage to linear engineering structures has changed significantly in plot 35 (Yano-Indigirskaya lowland), which confirms the chi-square test. The probability of defeat increased by 6–9 times according to the estimates obtained. This situation is observed when the lengths of linear structures are 3–4 km. However, in most of the key areas, there is no significant change in the probability of damage, despite ongoing climate change.
DRIFTING TIMBER FORMATION ON MUDFLOW RIVERS ON SAKHALIN ISLAND
Authors: Rybalchenko S. V.
Published: April 2024

The paper considers the regional features of the phenomena of timber drifting on mudflow rivers on Sakhalin Island. The regularities of mudflow formation in Sakhalin rivers and their mudflow regime are established and the factors causing timber drifting in the debris flow watercourses of Sakhalin Island are studied. Due to the history of Sakhalin terrain and macrorelief formation, the main mountain structures are composed of marine sediments. This promotes mudflows on rivers, the active development of exogenous processes on river slopes, and the flow of solid phase and woody vegetation into the channel and talvegs. As a result, the density of streams increases, their eroding and abrasive ability rises, which affects significantly channel deformations and involves timber drifting. High-density flows have an elevated transporting capacity, since they increase the pulling force of the flow affecting the midsection of the drifting timber root system, and also raise the timber buoyancy due to an increase in the pushing Archimedean force. Also, regional features include a large amount of liquid precipitation, the annual amounts of which in the valleys and on the coast are 800–1200 mm, and in mountainous areas can reach 1500–2000 mm. The main species of drifting timber drifting include broad-leaved trees (willow and alder), which, unlike coniferous wood, are more prone to form logjams and are most hazardous for culverts.
RESIDUES FROM MUNICIPAL SOLID WASTE INCINERATION: COMPOSITION, GROUNDWATER POLLUTANT LEACHING, TREATMENT TO REDUCE ENVIRONMENTAL IMPACT
Authors: Yuganova T. I. , Putilina V. S.
Published: April 2024

Incineration is a common method for treating municipal solid waste, which reduces its mass by 70% and volume by up to 90%. However, most of the non-combustible components are subsequently concentrated in a relatively small amount of incineration residues – bottom ash and fly ash – which must be further processed and / or landfilled. The article describes the formation and composition of incineration residues, issues of recycling and environmental regulation, leaching of pollutants and the problems of its testing, methods of treating incineration residues to reduce environmental impact.
GEOENVIRONMENTAL PROFILE OF A CITY FOR EFFECTIVE URBAN PLANNING
Authors: Zaikanov V. G. , Minakova T. B. , Buldakova E. V.
Published: April 2024

The article discusses modern approaches to planning urban areas in the context of implementing the Federal Project “Formation of a comfortable urban environment”. It is proposed to create a “geoenvironmental profile of the city” for the system integration of heterogeneous information about the city and geoenvironmental processes, which often limit the development of urban space. The formation of such a profile will allow integrating geoenvironmental data into strategic documents of territorial development and planning urban areas. This will contribute to effective planning to achieve sustainable and safe urban development.
PREDICTIVE NUMERICAL GEOFILTRATION MODEL OF GROUNDWATER INFLOW INTO THE GOREVSKY GOK QUARRY
Authors: Leont’eva E. V. , Sapachev R. Yu. , Grishin A. A.
Published: April 2024

Gorevskoe zinc-lead ore deposit is located within a unique terrain: it follows the left bank of the Angara River and lies underneath its current river bed, starting 38 km far from the Angara River mouth. This plays a significant role in the ore field hydrogeology and has a great impact on its further development. The complexity of ore field hydrogeology is defined by a number of natural factors, i.e., the occurrence of both aquifers as well as low-permeable and water-proof layers; tectonic failures (if any) and their functioning in terms of hydrogeology dynamics; variability in terms of water-bearing rocks hydraulic properties; water bodies on the surface and their connection with groundwater flows. All the above mentioned features allow us to classify Gorevskoe deposit hydrogeology as rather complex and complicated. The main task of the work performed was to evaluate and forecast the water inflow to Gorevskii open-pit mine and to determine the groundwater level at the end of mining operations. Because of the deposit rather complex hydrogeology, it was decided to perform the task on the basis of numerical geohydraulic modelling using finite difference method (FDM) in the environment of Visual MODFLOW software tools. The paper describes the following steps of works performed within the project: input data acquisition, processing and analysis; creation of concept-based hydrogeology model; development of hindcasting numerical model; model calibration in the context of environmental conditions and actual mining operations hosted within the open-pit; sensitivity analysis and advanced simulation to develop the forecasting numerical model. When performed, the forecast value in terms of groundwater inflow to the pit has been calculated. Thus, pit groundwater level at the end of mining operations has been developed. Following a number of scenarios applied, model sensitivity analysis has been made and this provided the basis to identify the factors that have the most essential impact on water inflow to the pit.
GEOFILTRATION MODELING OF WATER FLOWS TO PRODUCED PRIMARY DIAMOND DEPOSITS AND INJECTION IN ASSOCIATED AREAS
Authors: Yannikov A. M. , Struchkova A. S.
Published: April 2024

Safe development of primary diamond deposits in Western Yakutia requires constant monitoring of the hydrogeological regime of the exposed aquifer complexes within the quarry and mine fields of the deposits, as well as in the adjacent areas of drainage water injection. Over the entire period of development of the Alakit-Markhinsky, Daldynsky, Mirninsky and Nakynsky kimberlitic fields, about 400 million m3 of highly mineralized drainage water from quarries and mines were involved in the pumping-injection process. Complex cryohydrogeological conditions of the territory, i.e., lithological-facial specifics, continuous distribution of permafrost, structural confinement of kimberlite fields, fault-block structure of individual pipes, influence the dynamics of occurring changes and make the cryohydrogeological conditions of each individual pipe unique and having no complete analogues. In order to predict successfully and implement subsequently technical solutions aimed at controlling inflows of all types formed within mine and quarry fields, the Yakutniproalmaz Institute elaborated a program for the development, constant maintenance and updating of hydrogeological “digital twins” of all key mining deposits. The developed models take into account the influence of both natural factors and the applied schemes for opening and draining deposits, which impose their own limitations. The filtration problem was solved out using the licensed program FEFLOW, which performs modeling of hydrogeological conditions by the finite element method in a multilayer strata for areas of arbitrary configuration with boundary conditions of type I, II, III changing according to the known law in the presence of filtration heterogeneities in plan and section, as well as vertical filtration. The creation and constant updating of permanent digital models made it possible not only to acquire a modern tool for forecasting water inflows, but also helped to improve the planning process in terms of drilling drainage and injection wells, purchasing pumping equipment, etc. Deviation of predicted values from those actually observed within the short-term forecast for the period of use 2021–2023 ranged from 5 to 10%.
FUNCTIONAL DIVERSIFICATION OF THE CAROTENOID-CIS-TRANS-ISOMERASES CrtISO, CrtISO-L1, AND CrtISO-L2 IN TOMATO SPECIES (SOLANUM, SECTION LYCOPERSICON)
Authors: Efremov G. I. , Shchennikova A. V. , Kochieva E. Z.
Published: April 2024

The expression of the genes of carotenoid-cis-trans isomerases CrtISO, CrtISO-L1 and CrtISO-L2 was studied in comparison with the content of carotenoids in tomato species with different ripe fruit colors: green (Solanum habrochaites), yellow (S. cheesmaniae) and red (S. pimpinellifolium and S. lycopersicum). More ancient origin of CrtISO-L2 was shown in relation to CrtISO and CrtISO-L1. A similar content of total carotenoids (leaves) and β-carotene (ripe fruits) was found between the samples. Unlike fruits of S. habrochaites and S. cheesmaniae, red fruits accumulated lycopene and 20-30 times more total carotenoids. The highest level of transcripts both in leaves and in ripe fruits was detected for CrtISO. The CrtISO-L1 and CrtISO-L2 were transcribed high in leaves and low in fruits, except for the high expression of CrtISO-L2 in S. lycopersicum fruits. No relationship was observed between the content of carotenoids and the level of gene expression in the fruit. In the leaves, a positive correlation between the amount of carotenoids and the levels of CrtISO-L1 and CrtISO-L2 transcripts was found.
CONTENT OF DOCOSAHEXAENOIC ACID IN PECTORAL MUSCLES OF BIRDS CORRELATES WITH WING BEAT FREQUENCY
Authors: Gladyshev M. I.
Published: April 2024

Docosahexaenoic acid (22:6n–3, DHA) is a structural component of cell membranes and due to a peculiar form of its molecule exerts a high lateral pressure in the membranes enhancing activity of membrane-associated enzymes. A high content of DHA probably provides a high frequency of contraction and a continuous working of skeletal muscles. To estimate the probable physiological and biochemical role of DHA in muscle tissue, a relation of its contents in pectoral muscles of birds with wing beat frequency was evaluated. A high statistically significant correlation between the content of DHA in pectoral muscles of birds and species-specific wing beat frequency was found.
BIOLOGICAL ACTIVITY AND PROBABLE MECHANISMS OF ACTION OF DERIVATIVES OF TRYPTANTHRIN AND MOSTOTRIN ALKALOIDS
Authors: Popov A. M. , Degenkova L. G. , Moskovkina T. V. , Grammatikova N. E. , Kuzmich A. S. , Chernikov O. V. , Schekotichin A. E. , Stonik Academician Of the RAS V. A.
Published: April 2024

The alkaloid tryptanthrin and its water-soluble derivative mostotrin exhibit high antimicrobial and antitumor activity. To develop more active and less toxic preparations, syntheses and testing of the biological activities of a number of new and/or little-studied analogs were performed. Some of them have been shown to have higher cytotoxicity against tumor and antimicrobial cells than tryptanthrin and mostotrin. Thus, 8-fluorotryptanthrin effectively inhibits the proliferation of various tumor cell lines, namely: K-562/4, HCT-116 and HCT-116p53ko at lower concentrations than tryptanthrin, and 2,8-difluorostotrin exhibits a stronger antimicrobial effect against pathogenic bacteria S. aureus ATCC 29213 than mostotrin. It has been established that the antiproliferative properties of 8-fluorotryptanthrin and 8-fluormostotrin are associated with their ability in nanomolar concentrations to inhibit the cell cycle of tumor cells at the stage of transition from the G1 phase to the S phase. The data obtained indicate the prospects for further in-depth studies of their antitumor properties.
SYNTHESIS OF DEUTERIUM-LABELED PYRROLYLCARNOSINE
Authors: Shevchenko V. P. , Nagaev I. Yu. , Fedorova T. N. , Myasoedov N. F.
Published: April 2024

The effect of temperature on the effectiveness of the introduction of deuterium into pyrrolylcarnosine (PC) has been studied. Deuterium gas and heavy water were used as a source of deuterium. Isotope exchange was carried out using solid-phase and liquid-phase methods. It was found that it is better to use isotope exchange with deuterated water to obtain preparative amounts of labeled pyrrolylcarnosine. When using the solid-phase method, the main label is in pyrrole. The inclusion of deuterium at a higher temperature occurs more evenly. In addition, the use of deuterated water made it possible to reduce the amount of unlabeled isotopomer to almost 0%, obtain a product with a yield of 70% and a content of more than 7 deuterium atoms. It is established that the content of deuterium in the substance can be increased by pretreating the reaction mixture with deuterium gas. This approach opens up additional opportunities for synthesis of labeled compounds.
SPATIAL ECOLOGY OF THE SIBERIAN FOREST REINDEER (RANGIFER TARANDUS VALENTINAE Flerov, 1932) OF THE KUZNETSK ALATAU
Authors: Vasilchenko A. A. , Naidenko S. V. , Chistopolova M. D. , Rozhnov V. V.
Published: April 2024

For the first time, information is provided on the size of the home range of the Siberian forest reindeer (Rangifer tarandus valentinae) of the Altai-Sayan population of the Kuznetsk Alatau, the minimum distance that the deer passes per day, their changes and changes of habitats during the annual cycle. Possible reasons for the cyclical use of the habitat by forest reindeer are discussed.
DISTRIBUTION OF SIBOGLINIDS (ANNELIDA, SIBOGLINIDAE) IN THE LAPTEV SEA AND ADJACENT AREAS OF THE ARCTIC BASIN
Authors: Karaseva N. P. , Rimskaya-Korsakova N. N. , Kokarev V. N. , Simakov M. I. , Smirnov R. V. , Gantsevich M. M. , Malakhov V. V.
Published: April 2024

The purpose of the article is to assess the biodiversity of gutless marine worms of the family Siboglinidae (Annelida), whose metabolism is provided by symbiotic bacteria that oxidize hydrogen sulfide and methane. Within the geographical boundaries of the Laptev Sea, 7 species of siboglinids were found, another 1 species was found in the adjacent sector of the Arctic basin. The largest number of finds and the greatest biological diversity of siboglinids were found in the eastern part of the Laptev Sea in the field of numerous methane. One find was noted in the estuary area of the Lena River at a depth of 25 m. The possible connection of siboglinids with methane seepage areas is discussed.
THE XMAS-2 PROTEIN OF DROSOPHILA MELANOGASTER UNDERGOES CLEAVAGE INTO TWO FRAGMENTS
Authors: Kurshakova M. M. , Georgieva S. G. , Kopytova D. V.
Published: April 2024

The TREX-2 complex integrates several stages of gene expression, such as transcriptional activation and mRNA export. In D. melanogaster TREX-2 consists of four main proteins: Xmas-2, ENY2, PCID2, and Sem1p. Xmas-2 protein is the core subunit of the complex with which other TREX-2 subunits interact. Xmas-2 homologues have been found in all higher eukaryotes. Previously, it was shown that the human Xmas-2 homologue, GANP protein can undergo cleavage into two parts, probably during apoptotic cell death. We showed that the Xmas-2 protein of D. melanogaster also can split into two fragments. The resulting fragments of the protein correspond to the two large domains of Xmas-2. Protein splitting is observed both in vivo and in vitro. However, Xmas-2 cleavage in D. melanogaster is observed under normal conditions and is probably a part of the mechanism of transcription and mRNA export regulation in D. melanogaster.
EPTESICUS NILSSONII VARANGUS SUBSP. NOV. (VESPERTILIONIDAE, CHIROPTERA) FROM THE LOWER PLEISTOCENE OF THE TAURIDA CAVE IN CRIMEA
Authors: Lopatin A. V.
Published: April 2024

A new northern serotine bat Eptesicus nilssonii varangus subsp. nov. is described on the base of an incomplete skull and a mandibular fragment from the Lower Pleistocene deposits of the Taurida cave in the central Crimea. This is the earliest record of the species. The presence of E. nilssonii (Keyserling et Blasius, 1839) in the Early Pleistocene bat assemblage of the Taurida cave indicates that this species lived in the south of Eastern Europe before its spreading into Central and Southeastern Europe.
THE ROLE OF 20-HYDROXYECDYSONE IN THE CONTROL OF CARBOHYDRATE LEVELS IN DROSOPHILA MELANOGASTER UNDER SHORT-TERM HEAT STRESS
Authors: Bobrovskikh M. A. , Gruntenko N. E.
Published: April 2024

It is known that 20-hydroxyecdysone is one of the most important hormonal regulators of development, reproduction and adaptation to unfavourable conditions in insects. Here, we show for the first time that exogenous 20-hydroxyecdysone increases the content of two main insect carbohydrates, trehalose and glucose, in Drosophila melanogaster females both in normal conditions and under short-term heat stress. It has been found that the levels of both trehalose and glucose increase after thirty minutes of heat exposure, and return to their original levels after an hour and a half. A scheme of hormonal regulation of carbohydrate content under heat stress, involving 20-hydroxyecdysone, juvenile hormone and dopamine, is suggested.
MINUSES AND UNEXPECTED ADVANTAGES OF THE OLD WISTAR RATS’ BODY REACTION AT MODELING POST-TRAUMATIC STRESS DISORDER
Authors: Kondashevskaya M. V. , Artem’eva K. A. , Kozlova M. A. , Areshidze D. A. , Kaktursky L. V.
Published: April 2024

Old Wistar rats exhibit the same general signs of a PTSD-like condition as young animals, when modeling post-traumatic stress disorder (PTSD). At the same time, a number of behavioral features, psycho-emotional manifestations and myocardial state were revealed in old rats. For the first time, it was found a sharp rise in the level of circulating testosterone, which contributes to a more rapid decision on the direction of movement in the labyrinth space under stress in old rats, in contrast to young ones. The index of the ratio of testosterone to corticosterone levels can serve as a guideline for dividing the rat population into low- and high-anxiety individuals when modeling PTSD. The data on dysfunctional accumulation of mitochondria in the myocardium of intact and stressed old rats are priority. The information obtained may be useful in the development of drugs for the devastating consequences of PTSD, as well as senile changes in the myocardium.
MIDDLE HOLOCENE BROWN BEAR (URSUS ARCTOS) FROM BOLSHOY LYAKHOVSKY ISLAND (NEW SIBERIAN ISLANDS)
Authors: Cheprasov M. Yu. , Boeskorov G. G. , Novgorodov G. P. , Tikhonov A. N. , Grigorieva L. V. , Boulygina E. S. , Slobodova N. V. , Sharko F. S. , Protopopov A. V. , Nedoluzhko A. V.
Published: April 2024

Here, we present a detailed description of a unique find – a subfossilized brown bear (Ursus arctos L., 1758) that has been preserved in permafrost. The well-preserved carcass is dated to approximately 3.5 kilo years old (Kya). The results of classical morphological, computed tomography, and ancient DNA analyses of this Holocene brown bear mummy are discussed in this study.
ALLELOTOXICITY OF GREENHOUSE SUBSTRATES AFTER VEGETABLE CULTIVATION
Authors: Shoba S. A. , Gracheva T. A. , Fedotov G. N. , Ter-Petrosyants G. E. , Jancharov T. M. , Gorepekin I. V. , Ushkova D. A.
Published: April 2024

It is known that stresses during the cultivation of agricultural plants reduce yields, and the occurrence of stressful effects leads to the release of allelotoxins by plants into the soil. It has been suggested that this factor can have a noticeable effect on the vegetation of vegetables in greenhouses, and a decrease in the concentration of allelotoxins in greenhouse substrates can improve the vegetation of plants. To verify these assumptions, the allelotoxicity of greenhouse substrates and the content of microorganisms in them under well and poorly vegetating plants of cucumbers, tomatoes and peppers were determined. It was found that there are significantly more allelotoxins and fewer prokaryotes in the substrates under poorly vegetating plants, which confirmed the assumption about the significance of the allelotoxins influence on the cultivation of vegetables in greenhouses. The introduction of humate solutions with a high sorption capacity in relation to allelotoxins into the root zone of plants makes it possible to significantly improve the vegetation of cucumbers and may be a promising direction for increasing vegetable yields in greenhouses.
184–188 NUCLEOTIDES DELETION OF HUMAN TELOMERASE RNA DOES NOT AFFECT ON THE TELOMERASE FUNCTIONING
Authors: Shliapina V. L. , Dontsova O. A. , Rubtsova M. P.
Published: April 2024

Telomerase is a ribonucleoprotein complex, the main components of which are telomerase RNA and reverse transcriptase. Previously, it was shown in our laboratory that human telomerase RNA contains an open reading frame, starting at adenine in position 176. The open reading frame encodes the hTERP protein, and the deletion of nucleotides 184–188 of human telomerase RNA disrupts the open reading frame and leads to the absence of hTERP. Human telomerase RNA has a conserved structure, changes in which affect telomerase activity. In this work, we have shown that the deletion of nucleotides 184–188 of telomerase RNA does not affect the functioning of telomerase.
A NEW SPECIES OF SANDGROUSE (AVES: PTEROCLIDAE) FROM THE EARLY PLEISTOCENE OF CRIMEA
Authors: Zelenkov N. V.
Published: April 2024

Sandgrouse (Pteroclidae; Pterocliformes) are specialized ground birds of open arid landscapes with a very poorly studied evolutionary history. In the late Pliocene – early Pleistocene, Pteroclidae are known only from few localities in Southern Europe. The article describes a relatively large fossil sandgrouse from the early Pleistocene of the Taurida cave in the Crimea – this is the first finding of Pteroclidae in the ancient faunas of the Black Sea region and Eastern Europe. The unusual structure of the tibiotarsus makes it possible to describe the fossil form from Taurida Cave as a new species, Pterocles bosporanus sp. nov.
NEW MATERIALS ON THE MORPHOLOGY OF THE TEETH OF THE THREE-TOED HORSE (HIPPARION HOUFENENSE) FROM THE PLIOCENE OF WESTERN TRANSBAIKALIA (RUSSIA)
Authors: Kalmykov N. P.
Published: April 2024

This article is devoted to the morphological features of the teeth of the three-toed horse (Hipparion houfenense) from the Early Pliocene of Western Transbaikalia (Russia). It contains a number of diagnostic features that are unique to this taxon and distinguish it from other hipparion species, which allows us to speak about their true diversity at the final stage of their existence in the northeast of Inner Asia.
APPROBATION OF A NEW MODEL OF SECONDARY DAMAGE AFTER TRAUMATIC BRAIN INJURY BASED ON REPROGRAMMED RAT EMBRYO FIBROBLASTS
Authors: Rykunova E. B. , Mikeladze M. A. , Utepova I. A. , Chupakhin O. N. , Guzhova I. V. , Lazarev V. F.
Published: April 2024

The paper presents a new model of secondary injuries after traumatic brain injury. The model is based on the cultivation of rat embryonic fibroblasts reprogrammed to a neuronal phenotype in the presence of cerebrospinal fluid from injured rats. The presented model was used to test the therapeutic effect of inducers of the synthesis of chaperones from the classes of pyrrolyl- and indolylazines, which have neuroprotective properties.
METACERCARIAE IN COPROLITES OF SEALS OF THE GENUS PACHYPHOCA (CYSTOPHORINAE, PHOCIDAE) FROM THE LATE MIOCENE OF THE NORTH CAUCASUS
Authors: Tarasenko K. K. , Sivkova T. N.
Published: April 2024

Coprolites of the seal Pachyphoca volkodavi from the Upper Miocene deposits (Kherson) of the Fortepyanka locality (Republic of Adygea) were studied. Two out of five seal coprolites contained a structure resembling fish muscle tissue and included objects with morphology of trematode metacercariae. Obviously, the larvae of the parasite got into the digestive tract of seals from the fish they eat. Microscopic analysis of coprolites did not reveal helminth eggs, which indicates a possible absence of infection.
MESOPROTEROZOIC BIMODAL MAGMATISM OF THE ULUTAU TERRANE OF CENTRAL KAZAKHSTAN
Authors: Tretyakov A. A. , Degtyarev K. E. , Kanygina N. A. , Fedorov B. V.
Published: April 2024

In the southern part of the Ulutau terrane (Central Kazakhstan), a complex of volcanogenic rocks of basalt-rhyolite composition of the Zhiide series has been studied. Based on the U–Pb (SIMS) geochronological study of accessory zircons, an estimate of the age of rhyolites was obtained for the first time – 1338 ± 5 million years, which corresponds to the first half of the Ectasia period of the Mesoproterozoic. The features of the composition of the basic and acidic effusions indicate their formation in the context of continental rifting caused by the activity of the mantle plume.
DURABILITY IN WATER OF MATRICES FOR RARE-EARTH – ACTINIDE FRACTION OF HIGH-LEVEL RADIOACTIVE WASTE
Authors: Melnikova I. M. , Kalenova M. Yu. , Shchepin A. S. , Yudintsev S. V.
Published: April 2024

The durability in waters of matrices for rare-earth – actinide fraction HLW has been studied at 25 (1 atm.), 200 or 240°C (pressure of saturated vapor). The samples composed of Nd2ZrTiO7 (cubic pyrochlore-type structure) or Nd4(Ti,Zr)9O24 (orthorhombic symmetry, no natural analogue), phases were obtained by induction melting in a “cold” crucible. Leaching rate of Nd (imitator of REE-MA fraction) on the 28th day of experiment was lower than 5 × 10–8 g/(cm2 day). These results confirmed a very high durability of the ceramic waste forms in hot underground waters.
PHYSICO-CHEMICAL ASPECTS OF SOIL WATER STABILITY
Authors: Shoba S. A. , Shein E. V. , Ushkova D. A. , Gracheva T. A. , Salimgareeva O. A. , Fedotov G. N.
Published: April 2024

The influence of contact with water of soil aggregates of chernozem, sod-podzolic and gray forest soils on their water stability has been studied. It is established that an increase in the contact time of soil aggregates with water leads to a gradual decrease in their water stability. The conducted verification of the effect of salt solutions on the water stability of soil aggregates showed that the loss of water stability of aggregates in contact with water is not directly proportional to the disjoining pressure. It was found that when soil aggregates come into contact with water, fractal clusters of humus particles (F-clusters) are isolated from them. It is suggested that F-clusters, which are the basis of soil gels, determine the physical basis of soil waterproofness.
ARGINBAATAR (MULTITUBERCULATA, MAMMALIA) FROM THE NEW EARLY CRETACEOUS LOCALITY OF SHAVAR-OVOO IN MONGOLIA
Authors: Lopatin A. V.
Published: April 2024

The isolated upper premolar P4 of a multituberculate mammal is described from the new Early Cretaceous locality of Shavar-Ovoo in Mongolia (Övörkhangai aimag, Guchin-Us sum). It demonstrates the morpho-logy and measurements typical for Arginbaatar dmitrievae Trofimov, 1980 (Arginbaataridae). This is the first record of Arginbaatar (and the Early Cretaceous multituberculates of Mongolia in general) outside of the Höövör valley.
X-RAY COMPUTED MICROTOMOGRAPHY OF SULFIDE MINERALS: MICROINCLUSION STUDIES AND IMPLICATIONS FOR ORE GENESIS Sm–Nd DATING
Authors: Serov P. A. , Kadyrov R. I. , Kalashnikov A. O.
Published: April 2024

A microtomographic study of the internal structure of sulfide minerals from ore varieties of rocks of two industrial deposits of the Arctic zone of the Russian Federation – disseminated ore of the Pilgujarvi Cu–Ni deposit of Pechenga and ore gabbronorites of the platinum-bearing Fedorovo-Pansky complex (Kola Peninsula) was carried out. It is shown that all studied sulfide samples have a homogeneous structure without obvious defects or silicate inclusions larger than 1 µm. The absence of silicate microinclusions larger than one micron in sulfides suggests an isomorphic form of REE occurrence in sulfides and, to some extent, eliminates the debatable problem of the influence of microinclusions on the results of Sm–Nd isotope-geochronological studies of sulfides. The presence of smaller (10–500 nm) silicate microinclusions is highly likely to be unable to control the total REE budget in a sulfide mineral. The conclusion about the absence of a significant effect of microinclusions on the obtained ages is confirmed by the results of Sm–Nd dating using sulfides from the same mineral samples: the Sm–Nd ages of the ores of the Pilgujarvi Cu–Ni deposit were 1965 ± 87 Ma; ore gabbronorites of the Fedorovo-Pansky complex – 2482 ± 61 Ma, which is in good agreement with the dates obtained earlier using other isotopic systems (U–Pb, Re–Os).
GEOCHEMISTRY AND AGE OF MAFIC DYKES OF THE Be-DEPOSIT SNEZNOE: LATE PALEOZOIC MANTLE PLUME MAGMATISM EVIDENCE IN EASTERN SAYAN
Authors: Khubanov V. B. , Dolgoborodova K. D. , Tsygankov A. A. , Khubanova A. M. , Damdinova L. B. , Damdinov B. B. , Burmakina G. N. , Zarubina O. V.
Published: April 2024

Within the East Sayan rift zone of the Late Paleozoic Barguzin salic large igneous province (SLIP), along with alkaline-peralkaline granitoids with ore mineralization, mafic subvolcanic bodies (gabbroids, mafic dykes) are common. One of the typomorphic mafic – peralkaline granitoid association is the Snezhnoye beryllium deposit. Using the U–Pb LA–ICP–MS method, mafic dykes of the Snezhnoye beryllium deposit were dated. The age of zircons from the diabase (dolerite) dyke was 301 ± 6 Ma, and from the microgabbro one, 297 ± 2 Ma. The obtained dates are close to the age of fluorite-beryl mineralization (306 Ma) and peralkaline granites with Ta-Nb mineralization attributed to the Ognite complex (311–295 Ma). The geochemical features of mafic dykes suggest the generation of mafic magmas from an asthenospheric mantle source, which, taking into account the intracontinental setting, testifies in favor of the plume-mantle nature of mafic – alkaline-peralkaline granitoid magmatism of the East Sayan rift (rare-metal) zone.
ON THE MOMENT MAGNITUDE–LOCAL MAGNITUDE CALIBRATION FOR EARTHQUAKES IN THE NORTHWESTERN CAUCASUS
Authors: Zvereva A. S. , Sobisevich A. L. , Likhodeev D. V.
Published: April 2024

The spectral and dynamic parameters of the sources of regional seismic events have been studied for the territory of the Northwestern Caucasus using stations from the network of the Geophysical Survey, Russian Academy of Sciences and Crimean network. This is the first study for the region using such a large dataset. Moment magnitudes-Local magnitude calibration have been established for earthquakes of small and medium magnitude in the study area and linear dependence Mw = ML + 0.16 is recommended for use. An interdependence between the values of energy classes and local magnitudes was also obtained, which can help to further improve the procedures for processing seismological monitoring data at Caucasian stations and the formation of regional catalogs.
GEOLOGICAL POSITION, AGE AND SOURCES OF TALLAIN GABBRO-DIORITE-PLAGIOGRANITE PLUTON (SREDNEVITIMSKAYA MOUNTAINOUS COUNTRY)
Authors: Rytsk E. Yu. , Velikoslavinsky S. D. , Kyznetsov A. B. , Tolmacheva E. V. , Rodionov N. V. , Berejnaya N. G. , Lvov P. A. , Bogomolov E. S. , Andreev A. A. , Fedoseenko A. M.
Published: April 2024

The results of a geochronological study (U–Pb SHRIMP-II) of zircon from granodiorites and plagiogranites of the main phase of the Tallain pluton of the Baikal-Vitim belt are presented. The obtained estimates of the age of the magmatic cores of zircon from granodiorite and plagiogranite coincide with each other within errors and are interpreted as the age of crystallization of rocks of the main phase of the Tallain pluton 661 ± ± 6 million years. The weighted average age of the metamorphic zircon shells of these rocks is 637 ± 5 million years. High positive values of ɛNd (660) +7.2 and +7.3 in the rocks of the main phase indicate a juvenile source of the parent melts. Based on new and previously published geochronological data, a conclusion is made about the formation of similar late Neoproterozoic juvenile gabbro-granite associations of the Baikal-Vitim belt at the turn of 660 million years (Tallain complex) and 603–615 million years (Padorinsky complex).
EARLY CAMBRIAN DEPOSITS OF THE CONTINENTAL MARGIN (SOUTH OF TUVA, TEREGTIG FORMATION): RESULTS OF U–Pb DATING OF DETRITAL ZIRCONS AND Sr-CHEMOSTRATIGRAPHY
Authors: Ivanov A. V. , Letnikova E. F. , Shkolnik S. I. , Maslov A. V. , Vetrova N. I.
Published: April 2024

The sedimentation interval (530–520 Ma) of the Teregtig Formation deposits in southern Tuva is estimated based on U–Pb dating of detrital zircons from terrigenous deposits and Sr-chemostratigraphy of carbonate rocks. The main source area for clastic material, containing a large amount of detrital zircon grains, were rocks with an age of 580 Ma. The presence of a wide diversity of Precambrian detrital zircons indicates that sedimentation of the Teregtig Formation took place within a block of continental crust with a long evolutionary history. The presence of numerous chromites in their matrix indicates that the rocks of the Agardag ophiolite complex were also part of the eroded land during the accumulation of conglomerates of the Teregtig Formation.
THE FIRST REPORTED PLEISTOCENE BEAVER, Castor fiber (CASTORIDAE, RODENTIA), FROM THE GOBI ALTAI REGION OF MONGOLIA
Authors: Кlementiev A. M. , Khatsenovich A. M. , Bazargur D. , Tserendagva Y. , Marchenko D. V. , Rybin E. P. , Gunchinsuren B. , Olsen J. W. , Krivoshapkin A. I.
Published: April 2024

Here, we report a fragmentary Castor fiber (Linnaeus, 1758) proximal ulna from Tsagaan Agui Cave (Gobi Altai Mountains, southern Mongolia). This constitutes the first fossil evidence of this species from Mongolia. C. fiber is currently regarded as extinct in the Gobi Desert but fossilized remains recovered from cave deposits provide evidence that optimal habitat conditions for C. fiber existed in the Gobi Desert during some periods of the Pleistocene. Pleistocene C. fiber remains are relatively rare in neighboring regions, including Siberia and the Russian Far East. Here, we review the geographical distribution of fossil C. fiber in Central Asia, southern and eastern Siberia, and the Russian Far East.
THE IMPACT OF OIL PRODUCTION ON THE EROSION NETWORK DEVELOPMENT IN VOLGA-URAL STEPPE REGION
Authors: Myachina K. V. , Dubrovskaya S. A. , Ryakhov R. V. , Chibilev A. A.
Published: April 2024

The purpose of the work is to consider the features of the erosion network development of the in the steppe zone with mixed agricultural and oil-producing land use. The research was carried out on six key study plots with an area of 100 km2 each which allocated within the Volga-Ural agricultural and oil region. Satellite images and fieldwork were used to digitize, map and classify erosive landforms. The main directions of erosion activity at key plots are identified for the period from 1985 to 2020. The analysis of the length and density of the spatial distribution of the erosion elements is carried out. It is shown that the activation of production activities at an oilfield is capable of initiating new and strengthening current erosion processes. During the time of maximum technogenic load, the total length of the erosion elements can increase by more than 50%. There is a steady increase in the total length of the erosion network during the increase in the time of operation of the oil field. Agricultural lands located in the zone of the oilfield are influence increased risk of soil erosion. In such cases, the tasks of protecting land from technogenic transformations and their return to agricultural circulation are actualized.
AGE OF ALKALINE ROCKS FORMATION IN THE AREA ARYSKAN RARE-METAL DEPOSIT, EASTERN SAYAN
Authors: Nikiforov A. V. , Ivanova A. A. , Yarmolyuk V. V. , Salnikova E. B. , Kotov A. B. , Kozlovskya A. M. , Khertek A. K. , Plotkina Y. V. , Kudryashova E. A. , Galankina O. L. , Polyakov N. A.
Published: April 2024

The age relationships between the alkaline rocks from the region of the rare-metal (Y, REE, Nb, Ta) Aryskan deposit have been determined. Metamict zircon with high content of U, Th was used as a geochronometer. A dedicated treatment protocol was used for sample preparation for geochronological U–Pb (ID TIMS) studies. Dating of zircon from alkaline granites of the Aryskan and nearby Astyg massifs showed that their formation occurred almost simultaneously, 448 ± 1 and 446 ± 1 million years ago, respectively. The supposed genetic relationship of alkaline granites with the accomodating alkaline-feldspar syenites formed 472 ± 2 million years ago (zircon, U–Pb, ID TIMS), has not been confirmed.
U–Pb AGE OF DETRITAL ZIRCON IN THE CEMENT OF EARLY PRECAMBRIAN POLYMICTIC CONGLOMERATES OF CENTRAL KARELIAN DOMEN, KARELIAN PROVINCE, FENNOSCANDIAN SHIELD
Authors: Kucherovskiy G. A. , Chekulaev V. P. , Egorova J. S. , Kuznetsov A. B. , Arestova N. A. , Zaitseva T. S. , Adamskaya E. V. , Plotkina Yu. V.
Published: April 2024

U–Th–Pb LA-ICP-MS was used for dating detrital zircons extracted from the cement of the Neoarchean and Palaeoproterozoic polymictic conglomerates of the Karelian province, Fennoscandian shield. For the first time obtained a chemical composition of terrigenic and volcanogenic rocks of the gimolskaya formation. Obtained data showed that the detrital zircons from the cement of conglomerates of different ages yield similar results of about 2750 Ma. In the Neoarchean conglomerates of the Sukkosero area dominate clasts of the gneissic tonalite and plagioporphyry. They are identical in chemical composition with the Neoarchean (2.78–2.73 Ga) TTG, granodiorite, and metadacite of the Central-Karelian domain. The feature of these rocks is increased content of Ba (900–1200 ppm), Sr (600–700 ppm), and ratios Sr/Y = 34–90, (La/Yb)n = = 17–30. The chemical composition of the cement (the values of CIA 55 and the negative values of the function DF(x)) is similar to the composition of clasts, which means cement is composed of finer clasts of the same rocks. The Paleoproterozoic conglomerates of the Vottomuks area contain zircon from felsic rocks of the Neoarchean basement/ The chemical composition of the cement of the Paleoproterozoic conglomerates and the predominance of basaltic andesites of sumii is evidence of the post-sumii (2.45 Ga) age of these rocks. The absence of the Paleoproterozoic zircon in cement can be the result of the absence of it in the Paleoproterozoic source rocks. The age of Neoarchean conglomerates from the gimolskaya formation is less than 2.75 Ga.
MORPHOLOGY AND SEDIMENTARY COVER STRUCTURE OF THE GAKKEL RIDGE’S LONG SEGMENTS
Authors: Piskarev A. L. , Kaminsky V. D. , Poselov V. A. , Kireev A. A. , Savin V. A. , Smirnov O. E. , Bezumov D. V. , Ovanesian G. I. , Elkina D. V.
Published: April 2024

The rift valley of the Gakkel Ridge was divided into three segments according to the sub-bottom profilling and seismoacoustic studies, carried out by R/V “Akademik Fedorov” at the Gakkel Ridge in 2019–2020, and on seismic data of 2011–2015. West of 75° E, the rift valley crosses the Gakkel Ridge approximately in the middle, as it was expected based on the assumption that the rift valley runs along the spreading axis that formed this ridge. East of 75° E the rift valley shifts to the southwestern edge of the ridge and, thus, it can be concluded that the spreading axis jumped to its present position relatively recently (in the Pliocene). Finally, to the south of the Gakkel caldera (about 120° E, 81° N), the rift valley is manifested itself in the sections as a young graben in many kilometers of sediments.
METHANE IN CARBONATE MELT INCLUSIONS FROM THE ROCK-FORMING MINERALS OF CALC-SILICATE ROCKS FROM THE KOKCHETAV MASSIF
Authors: Mikhno A. O. , Vinogradova Yu. G. , Rashchenko S. V. , Korsakov A. V.
Published: April 2024

Secondary inclusions of carbonate melt were studied in garnets and clinopyroxenes from ultrahigh pressure calc-silicate rocks. Secondary inclusions are located in healed cracks associated with large (100 µm – 3 mm) carbonate inclusions in garnet. In some cases, healed cracks intersect inclusions of potassium-bearing clinopyroxene in garnet. Since the amount of K2O in healed cracks in clinopyroxene-inclusions reaches 0.64 wt. %, it was concluded that their formation and healing occurred at the ultrahigh pressure metamorphic stage. Raman spectra interpretation of secondary carbonate melt inclusions in garnet and clinopyroxene confirmed the presence of the following phases: methane, graphite, calcite, dolomite, muscovite, and phlogopite. The obtained results imply for the ultrahigh-pressure metamorphic stage in the evolution of calc-silicate rocks from the Kokchetav massif, corresponding to the methane accumulation in the carbonate melt.
THE FIRST DATA ON THE AGE OF METAMORPHIC ROCKS OF THE SYNCHYGA BLOCK OF THE JIAMUSI CONTINENTAL MASSIF (CENTRAL ASIAN OROGENIC BELT)
Authors: Ovchinnikov R. O. , Sorokin A. A. , Xu W. L. , Khubanov V. B.
Published: April 2024

The paper presents the results of U–Th–Pb geochronological studies of zircons from metamorphic rocks of the Amur group of the Synchyga Block of the Jiamusi continental massif. It is shown that the garnet-biotite-sericite schists of the Amur group have a primary sedimentary origin. The lower depositional age of the protolith can be determined by the age of the youngest zircons from group with Neoproterozoic ages ~832 Ma. The upper age boundary of protolith, apparently, corresponds to the age of metamorphic zircons ~533 Ma. Thus, the schists of the Amur group of the Synchyga Block are of Neoproterozoic in age rather than Early Precambrian, as was accepted earlier.
MAGMA COMPOSITION AND FORMATION CONDITIONS OF ALKALI-SALIC ROCKS OF THE EARLY MESOZOIC ADAATSAG BIMODAL ASSOCIATION OF THE KHARKHORIN RIFT ZONE OF CENTRAL ASIA (DATA FROM THE STUDY OF MELT INCLUSIONS IN MINERALS)
Authors: Andreeva I. A. , Yarmolyuk V. V. , Borisovsky S. E.
Published: April 2024

Based on the method of investigation of melt inclusions using electron and ion microprobe, the magma composition and formation conditions of comendites of the Early Mesozoic Adaatsag volcanic association (Mongolia) were studied. The mechanisms leading to the accumulation of rare and rare earth elements in them were determined. Melt and fluid inclusions are found in quartz from the comendites, collected from different parts of the volcanic sequence. The melt inclusions consist of glass, a gas bubble and daughter minerals represented by fluorite, polylithionite and potassium feldspar. The use of the Raman spectroscopy method made it possible to study the composition of the gas phase in melt inclusions. It is determined that the predominant components of the gas phase are water and hydrogen. Fluid inclusions are represented by aqueous solutions that correspond to KF in composition. The concentration of KF in the solution reach up to 4.0–4.1 wt. %. Thermometric experiments with melt inclusions and analysis of the composition of glasses of homogenized melt inclusions in quartz of the comendites showed that the crystallization of magmas of these rocks occurred from water-saturated rare-metal melts with high contents of Li, Zr, F, Rb, Nb, Y and Th at temperatures of 880–930°C and at a pressure of 1000 bar at a depth of ~3.5 km and was accompanied by degassing processes. Comparison of the obtained data on the study of melt inclusions in the phenocrysts of the alkali-salic rocks of the same age volcanic associations Adaatsag, Dzarta-Кhuduk and Sant, developed within the Kharkhorin rift zone, revealed general patterns of their magma evolution. This allowed us to propose a similar mechanism of their formation, involving the accumulation of many rare and rare-earth elements, as well as volatile components (F, H2O) in the process of crystallization differentiation. Subsequently, a salt melt rich in Li, F and water could be separated from such comendite magmas. The detection of fluoride aqueous inclusions in quartz allows us to suppose the further evolution of the salt melt leading to the appearance of a concentrated aqueous fluid and the possible participation of the latter in metasomatic processes.
THE FIRST DATA ON MIDDLE JURASSIC DINOFLAGELLATE CYSTS AND FORAMINIFERS OF THE RUSSIAN FAR EAST
Authors: Goryacheva A. A. , Glinskikh L. A. , Dzyuba O. S. , Urman O. S. , Shurygin B. N.
Published: April 2024

Information about the first records of dinocysts and foraminifers in the Middle Jurassic deposits of the Russian Far East and their taxonomic affiliation is given. The use of foraminiferal and ostracod assemblages as a tool for biostratigraphic subdivision and correlation of the Middle Jurassic sections of this region is very difficult due to the poor preservation and limited occurrence of these microfossils. Findings of dinocysts Endoscrinium galeritum, Tubotuberella cf. apatela, Wanaea fimbriata, Meiourogonyaulax cf. caytonensis raise the question of correcting the stratigraphic range of the lithological formations recognized in the Middle Jurassic.