Abstract. Iron ore deposits play a significant role in Mongolia’s mineral-based economy and require detailed geological and geophysical investigation for effective exploration and resource evaluation. This study focuses on the Bargilt iron ore deposit located in Khentii Province, Mongolia, within the MV-016657 license area operated by the state-owned enterprise Mongolrostsvetmet. The main objective of the study is to characterize the mineralogical composition, rock properties, and subsurface distribution of ore-bearing zones for better understanding of the deposit’s structure and potential. A combination of field geological mapping, petrographic analysis, and petrophysical interpretation was used to determine the mineral composition and textural relationships. Representative samples of ore-bearing (59 samples) and host rocks (440 samples) have been collected, measured and analyzed. Magnetite was identified as the dominant ore mineral accompanied by minor accessory minerals, while the host rocks are mainly composed of silicate gangue minerals. Petrophysical data were interpreted to identify subsurface anomalies associated with iron-enriched zones and to identify structural factors influencing mineralization. The study results indicate that the iron ore mineralization is structure-controlled and exhibits a variable spatial distribution influenced by lithological boundaries and fault systems. Integration of geological and petrophysical datasets provides a more reliable model of ore body geometry and its continuity. The study results demonstrate the effectiveness of combined methods for improving exploration accuracy and can serve as a basis for further detailed assessment of the Bargilt iron ore deposit for future development planning.

This article presents a program of key laboratory studies required for experimental verification of a predictive model for enhanced oil recovery at the Nasiriyah field (Iraq, Cretaceous Mishrif formation). Previously performed numerical modeling demonstrated that injection of fractionated natural gas enriched with C3–C4 components (liquefied petroleum gases) can achieve miscible oil displacement under reservoir conditions of P = 25 MPa, T = 95°C. However, a comprehensive experimental verification is required to transition from predictive calculations to a technologically sound solution. The proposed program includes three interrelated blocks: 1) pressure–volume–temperature (PVT) studies of reservoir oil – verification of thermodynamic properties, calibration of the Peng–Robinson equation of state, and determination of swelling factors upon contact with gas agents; 2) determination of minimum miscibility pressure by the slim-tube method for raw associated gas, enriched mixture (60% C1 + 40% C3–C4), and liquefied petroleum gases; 3) core flooding experiments on core samples from the Mishrif formation – comparison of continuous gas injection and water-alternating gas flooding. The expected results enable calibration of the reservoir simulation model, justification of the optimal gas agent and injection mode, as well as preparation of a feasibility study for the industrial implementation at the Nasiriyah field and similar carbonate reservoirs in Southern Iraq.

The article considers potential oil and gas accumulation zones in the northern regions of Western Yakutia. The subthrust zone of the periphery of the Verkhoyansk folded structures is of particular interest for oil and gas exploration, especially on the Kitchansky protrusion and adjacent sections of the Verkhoyanskaya Arc, including the northern margin of the Aldan branch up to the Tompon depression, as well as within the northwestern Verkhoyansk cover. Within the study area, it is proposed to consider potential oil and gas accumulation zones located along migration pathways and at their ends as forecasting objects, highlighting the most likely directions of hydrocarbon movements. From the perspective of the potential for non-anticlinal trap formation in the lower part of the Permian deposits, the region adjacent to the northern slope of the Yakut Arch is of interest. Permian and Triassic deposits resting directly on the crystalline basement represent a promising complex. The mudstones of the Nedjelinskaya formation are likely to serve as a cap rock. For regional geological work, it is proposed to consider promising oil and gas objects within the Kitchanskaya and Yakutskaya oil and gas accumulation zones. This work is aimed at the study of the geological structure of the junction zone of the southeastern part of the Predverkhoyansky trough, the northern slope of the Aldan anteclise and the southern side of the Vilyui syneclise, the nature of structural and lithological relationships, the areal distribution of stratigraphic complexes within the sedimentary cover, the identification of oil and gas promising reservoirs and zones of potential oil and gas accumulation, the refinement of oil and gas prospects and estimation of predicted hydrocarbon resources. It is assumed that quantitative oil and gas accumulation will belong to traps of a predominantly non-anticlinal (stratigraphic) type.

The ice conditions of lakes serve as an indicator of regional climate change. This study focuses on Lake Kulinda, located at the northern end of Lake Baikal, Russia. The study analyzes the patterns of ice melting in this lake in April 2019, 2021, 2023, and 2025, and identifies the factors influencing the evolution of ice lakes in this region using Landsat-8 and Landsat-9 remote sensing data and GIS analysis tools. The results show that between 2019 and 2025, the ice cover of Lake Kulinda decreased from 9.17 km² to 8.86 km², resulting in a total reduction of 0.31 km² with an average annual decrease of 0.05 km². The rate of ice melting initially increased and then decreased. The largest annual reduction was observed in the period 2021–2023 (0.08 km²), while in the period 2023–2025 the rate slowed down (0.04 km²), which indicates a slowdown in the dynamics of the lake’s ice cover. The retreat of the ice cover occurred along the coastal zones, especially in the southeastern and northwestern parts, while the central part remained covered with ice. The boundary between ice and open water gradually shifted towards the center of the lake every year. Changes in the area of the ice cover are associated with the warming climate of the region. The phases of rapid melting in 2021–2023 coincided with the statistical spring warming, and the subsequent slowdown is related to the nonlinear interaction between natural climate fluctuations and the dynamics of the ice cover. This indicates the adaptive capabilities and self-regulation of the lake’s ice cover. The research results can be used in monitoring the phenological state of the ice cover formation in the lakes of the Northern Baikal region, which will contribute to a better understanding of climate change in the region.

The paper reports the results of an experimental investigation into the electromagnetic properties of a ceramic material obtained from white-burning clay from the Kornilovskoye deposit with the addition of non-ferrous metals (lead and copper) at varying concentrations. The relevance of the study is driven by the need to develop effective radar-absorbing materials for protection against electromagnetic radiation across a wide frequency range. The purpose of the study is to investigate the relationship between the reflection and absorption coefficients of electromagnetic waves and the metallic phase content within the ceramic matrix, as well as to identify the optimal composition of the material for radar-absorbing coatings formation. The study employs the following research methods: S-parameter analysis in the 0–18 GHz frequency range and time domain reflectometry (TDR), which allows for the estimation of the reflected signal level. It has been found that the addition of lead and copper significantly affects the electrophysical properties of the material, altering its dielectric permittivity and electrical conductivity. It has been shown that at the metal concentration of 20% an insufficient degree of electromagnetic radiation absorption is observed, whereas at 40%, the reflectivity increases due to the rise in conductivity and surface effects. The most effective radar absorption properties are achieved at the metallic phase content of approximately 30%, which corresponds to the formation of an optimal material structure that ensures a balance between dielectric and conductive losses. The obtained results indicate the promise of using the developed ceramic material as a basis for radar-absorbing coatings, shielding structures, and protective elements against electromagnetic exposure.

The Olkhon region is a key structure (geodynamic polygon) straddling the boundary between the Siberian craton and the Central Asian folded belt. In this regard, finding out the history of their interaction in time and space is an interesting and relevant task, the solution of which provides a good opportunity to discuss the prospects for a different interpretation of the array of new geological and geophysical data for the Western Baikal region. The purpose of physical and geological modeling is to clarify the geological structure of the collisional suture of the Siberian craton – Olkhon terrane system to create next-generation geological maps. For this purpose, ground magnetic surveys and petrophysical studies have been conducted at the Anga river section where collisional suture metamorphic features are prominent. These studies included the collection of oriented samples from blastomylonites of various types and the intruding dolerites, aged 500–470 and 290 million years, respectively. According to geologists, dolerites form a dike of northeastern strike, no more than 5 m thick and up to 2 km long. New information on geochronology, petro- and paleomagnetism of the considered dolerites contradicts this hypothesis. The performed physical-geological modeling showed that the dolerites form an intrusive body of a more complex shape than the dike (most likely a sill about 200 m thick), and made it possible to find a compromise solution for the interpretation of previously obtained material. On this basis, it is possible to conclude that fairly active tectono-magmatic events occurred here in the Early Permian, which most likely were associated with the formation of the Angara-Vitim batholith in Transbaikalia. According to the obtained samples (N = 19), after introducing a tectonic correction for the bedding elements of the main fault plane of the Primorsky fault, a virtual geomagnetic pole has been calculated for the Early Permian (295–275 Ma) with coordinates: F = 45° N, L = 133° E, dp/dm = 18.2/19.0°. Thus, to clarify the Aerospace geological map and the history of geodynamic development of the Olkhon region, it is proposed to include a wide range of geophysical methods in the research.

The enormous-scale processes of platform stages of magmatism and paleovolcanic activity on the Siberian Platform are characterized by the effusio of gigantic volumes of basaltic magma, the formation of kimberlite fields, iron, rare earth, and sulfide ores, as well as changes in the localization of hydrocarbon deposits. These processes, initiated by the passage of the craton over the “hotspot” of the giant super-plume encompassed many aspects of the evolution of hydrogeological, including magmatic-hydrothermal, paleosystems in the sedimentary cover of the ancient craton. This paper examines the nature and concept of «fluid–dynamic structure» as part of the magmatic-hydrothermal model of volcanogenic-sedimentary cover evolution using the Angara-Lena artesian basin as an example. The purpose of the study is to substantiate a magmatic-hydrothermal formation model of fluid-dynamic structures and transformation of rare-metal industrial brines in the volcanogenic-sedimentary cover of the Siberian Platform. This study uses archival and up-to-date seismic and electrical exploration data, deep-drilling geotechnical datasets, and hydrogeochemical brine sampling. The authors interpret the subvertical and associated subhorizontal zones of reflection loss observed in seismic sections at a number of sites as fluid-dynamic structures formed during the magmatic and postmagmatic pneumatolytic-hydrothermal stages. The impact of magmatic melts rising into the upper crust through deep crustal faults and areas of increased permeability of the tectonosphere led to the pulsed formation of vapor-dominated fluid pressure systems. According to the authors, the circulation of vapor-hydrothermal fluids through secondary filtration systems led to profound transformations in the hydrogeochemistry of the primary sedimentogenic brines of the sedimentary basin. At the same time, the reservoir rocks were transformed, with the development of high-capacity natural reservoirs driven by hydraulic fracturing, thermolift, and vapor-gas and fumarolic activity.The stages of platform magmatism and post-magmatic processes played a crucial ore-forming and ore-localizing role in the metallogeny and mineral genesis of industrial metal-bearing brines, determined the secondary concentration of the richest «liquid» ore of rare, dispersed elements, and mineral salts, including bromine, alkali metals – lithium, rubidium, cesium, potassium, and compounds with alkaline earth calcium and strontium.