Timofey Leshukov

Studying dust pollution intensity from the mining industry is essential for the sustainable development of industrial regions worldwide, as it balances economic growth, social well-being, and environmental safety. This study presents the results of a dust pollution study of snow near a coal open pit (during the stripping and pre-mining stage) in the Kemerovo Region-Kuzbass, Russia. We sequentially assessed the mass of PM₁₀ and PM_0.1 and the fractional composition of PM₁₀ using light microscopy, determined the polycyclic aromatic hydrocarbon (PAH) content using high-performance liquid chromatography (HPLC), and conducted X-ray diffraction (XRD). We found that the mineral composition of the PM₁₀ fraction contained diffraction peaks from quartz, talc and clay minerals, while calcite, bassanite and zeolite were discovered in PM_0.1. The total dustiness was 605 ± 24 μg/cm² and 204 ± 18 μg/cm² for PM_0.1 and 401 ± 14 μg/cm² for PM₁₀. Particles in the 0.1–2.5 µm range predominated within PM₁₀, with a mean size of ~1 µm. For all directions, there were no significant trends of an decrease in dust mass with growing distance from the open-pit coal mine. The increase in PAHs in snow coincided with the prevailing eastern wind direction during the snow accumulation season. The present study is important for understanding the processes of dust formation, transport, and deposition during coal mining preparation and operation, dust mineral composition, the amount of PAHs in the snow cover, and to take into account the role of the meteorological conditions, particularly wind direction, and topography.

Актуальность работы. Использование титанита в качестве минерала геохронометра в последнее время приобретает все большую популярность. При этом в гранитоидах встречается как магматический, так и метаморфический титанит. Последний является продуктом низкоградного преобразования биотита. Индикатором генезиса титанита могут служить содержания железа, фтора и глинозема, а также их разнообразные отношения. Наиболее информативными в составе фтор-глиноземистого титанита могут выступать отношения Fe/Al и (Fe+Al)/F, указывающие на магматическое или метаморфическое происхождение титанита. Целью исследования является изучение химического состава титанита для определения его генезиса в гранитах турочакского комплекса и возможности его последующего использования для геохронологических исследований. Объектом исследования являлся титанит из гранитов третьей фазы внедрения турочакского граносиенит-гранит-лейкогранитового комплекса (γD1t), расположенного в Горно-Алтайском фрагменте Алтае-Минусинского ранне-среднедевонского магматического пояса Алтае-Саянской складчатой области (АССО). Методы исследования включали: петрографическое описание пород, изучение состава титанита с последующим выполнением кристаллохимических пересчетов состава титанита зарядным методом и составление формул, а также анализ отношений Fe/Al и (Fe+Al)/F в составе титанита. Химический состав определялся в полированных шлифах на сканирующем электронном микроскопе (СЭМ) Tescan Vega3 с приставкой рентгенофлуоресцентного энергодисперсионного анализа Oxford. Результаты исследований. Установлено, что титанит из гранитов турочакского комплекса является фтор-глиноземистым и имеет следующую формулу (Ca0.97-1.00Fe0.01-0.02)Ʃ0.99-1.01(Ti0.79-0.81Al0.18-0.22)Ʃ0.98-1.01(Si0.98-1.00Al0-0.02)Ʃ1.00O4(O0.81-0.86F0.14-0.19)Ʃ1.00. Отношения в его составе Fе/Al (менее 1:8) и (Fe+Al)/F (близко к 1:1) свидетельствуют о метаморфическом генезисе титанита и, как следствие, невозможности его применения для целей геохронологии гранитов турочакского комплекса Relevance. The use of titanite as a geochronometer mineral has recently become increasingly popular. In this case, both magmatic and metamorphic titanite are found in granitoids. The latter is a product of low-grade biotite transformation. The content of iron, fluorine and alumina, as well as their various ratios, can serve as an indicator of titanite genesis. The most informative in the composition of fluorine-aluminous titanite can be the Fe/Al and (Fe+Al)/F ratios indicating the magmatic or metamorphic origin of titanite. The aim of the paper is to study the chemical composition of titanite to determine its genesis in the granites of the Turochak complex and the possibility of its subsequent use for geochronological studies. The object of the study was titanite from granites of the third phase of the intrusion of the Turochak granosyenite-granite-leucogranite complex (γD1t) located in the Gorno-Altai fragment of the Altai-Minusinsk early-middle Devonian igneous belt of the Altai-Sayan folded region (ASFR). The research methods included: petrographic description of rocks, study of titanite composition with subsequent crystallochemical recalculations of titanite composition by the charging method and compilation of formulas, as well as analysis of Fe/Al and (Fe+Al)/F ratios in titanite. The chemical composition was determined in polished sections on a Tescan Vega3 scanning electron microscope (SEM) with an Oxford X-ray fluorescence energy-dispersive analysis attachment. Results. It was established that titanite from the granites of the Turochak complex is fluorine-alumina and has the following formula (Ca0.97-1.00Fe0.01-0.02)Ʃ0.99-1.01(Ti0.79-0.81Al0.18-0.22)Ʃ0.98-1.01(Si0.98-1.00Al0-0.02)Ʃ1.00O4(O0.81-0.86F0.14-0.19)Ʃ1.00. The ratios in its composition Fe/Al (less than 1:8) and (Fe+Al)/F (close to 1:1) indicate the metamorphic genesis of titanite and, as a consequence, the impossibility of its use for the purposes of geochronology of the granites of the Turochak complex

The study of the halogen (F and Cl) and sulfur contents in apatite from granodiorites and leucogranites of the Tigertysh complex (Є-O1t) was carried out, which may indicate the potential ore content of granitoids. Apatites of granodiorites are confined mainly to amphibole grains, less often located in quartz and feldspars, and correspond in composition to fluorapatite (F = 2.45–2.76 wt. %, Cl = 0.02–0.03 wt. %). In leucogranites, apatite is confined to feldspars and biotite, and corresponds in composition to hydroxyl- and fluorapatite (F = 1.50–1.80 wt. %, Cl = 0.33–0.52 wt. %). In apatite from granodiorites, the sulfur content is maximum in grains confined to amphibole and is 0.05–0.11 wt. %, while in apatite from quartz and feldspars it is no more than 0.04 wt. %. The sulfur content in apatite from leucogranites does not depend on its confinement to different minerals and is 0.04–0.07 wt. %. Based on the F, Cl and S contents in apatites of granitoids of the Tigertysh complex, it can be assumed that gold-sulfide-quartz mineralization may be associated with granodiorites, and Cu-porphyry mineralization with leucogranites.

The study of the influence of geological structure (e.g., faults) on radon emanations is usually applicable provided that there are conditionally background (control) territories with which radon indicators will be compared. In the presented study, we selected an area where pre-Cenozoic faults that could potentially be associated with the radon hazard of the Kuznetsk coal basin were not identified. The cover deposits in the study area are represented by loamy and clayey strata overlying the Paleozoic sedimentary cycles. The radon field was estimated based on the radon flux density (RFD) and radon activity concentration (RAC) in the soil gas. The RAC was measured in two ways—by the sorption method on activated carbon and by the method of active sampling of soil gas from a borehole. At the same time, the role of meteorological conditions and the physical properties of the soil in the radon field was assessed. Our study shows that local variations in the physical properties of the soil are insignificant and do not have a significant effect on the RAC in the soil gas of the Kuznetsk coal basin, with the exception of soil moisture. High values of RAC in the territory considered as conditionally background, in the absence of pre-Cenozoic faults, suggest other causes (the presence of the latest Neogene–Quaternary faults, high concentrations of ²²⁶Ra, or other insufficiently studied causes). Due to the absence of faults, it is possible to assume a diffusion type of radon transfer in the geological environment, which indicates a shallow source of radon in such high concentrations. Our results indicate that studies of the ²²⁶Ra content and additional studies of the radon hazard of similar areas should also be carried out.

The study specifies the changes in radon activity concentration (RAC) in soil gas with depth and emphasizes the significance of the meteorological factor for deeper boreholes. Radon activity concentration was measured in 0.6 m, 1 m and 1.5 m boreholes, and the depth gradient was also calculated. Spatial patterns were estimated using an autocorrelation index. RAC ranged from 9454 ± 439 Bq/m³ for 0.6 m, 16,031 ± 602 Bq/m³ for 1 m and 22,049 ± 937 Bq/m³ for 1.5 m. RAC increased with depth at most of the study sites and behaved quite uniformly in spatial terms. At the same time, no significant differences in the activity of uranium (²³⁸U) series isotopes at different soil depths were detected. Significant spatial variability in radioactivity and the physical properties of soils is noted. The highest gradient was between 0.6 and 1 m. It was found that with increasing depth the connection between the RAC and the meteorological conditions (temperature and humidity) of the surface layer of the atmosphere is lost. It follows that for shallow boreholes it is necessary to consider the influence of meteorological conditions. RAC in 1 m boreholes correlates with 1.5 m and 0.6 m boreholes, but no correlation was found for the 1.5 m and 0.6 m boreholes themselves. Thus, 1 m boreholes are optimal for radon monitoring. A high level of RAC indicates a high potential for indoor radon exposure in this territory, with corresponding epidemiological consequences in the long term.

Geographic patterns determine geogenic radon factors that, changing over the territory, form spatial structures of different scales associated with regional and local variations. The study of these structures is important for assessing the possibility of using limited data to predict geogenic radon potential. Our research focuses on the study of the physical properties of soils (moisture, soil density, porosity and void ratio) in the Kuznetsk coal basin. Their variations are studied using statistical methods, a variogram cloud and spatial autocorrelation of data. Soil moisture and porosity have the greatest variability in space and with depth. We conclude that the assessment of geogenic radon predictors requires consideration of the variation coefficient and autocorrelation indices at different scales. Based on the variability of humidity and the fairly homogeneous nature of the studied soils (loams), to assess the radon hazard, it is necessary to study the influence of climatic conditions, since the permeability of the environment for radon will be determined by soil moisture. With the predominance of substantially clayey soils, it is necessary to study the content of ²²⁶Ra in the upper horizons, since it is assumed that radon is predominantly diffusely transferred, in which its role is dominant.

Overburden rock massifs resulting from open-pit coal mining are very common objects in the world’s mining regions. These locations pose a significant challenge as the global mining industry expands. These dumps are capable of self-burning for quite a long time. The displacement and sliding of these massifs can cause catastrophic consequences. In addition, these objects emit a significant amount of greenhouse gases into the atmosphere. Therefore, it is necessary to manage such objects and implement appropriate measures to limit their impact on the environment. In this work, we studied soil radon volume activity (VAR) and radon flux density (RFD) on the surface of the overburden rock massif of coal-bearing mining rocks and also made visual fixation of disturbances in the body of the massif, which appeared in the process of its movement. We found anomalies of VAR and RFD on the surface of the overburden extending from north to south. These anomalies were extended along the strike of the faults found in the body of the massif. Additionally, the radon anomalies coincided with the anomalies of methane gas emission previously measured for this object. Thus, we determined that the exit of gases from the body of the massif is carried out through fault (weakened) zones in the body of the massif. According to the results of the study, we propose to carry out radon monitoring in order to detect the spontaneous ignition process of the massif or the increase of its mobility. This will also allow us to take appropriate measures to stabilize the massif or to extinguish the dump before or simultaneously with the biological stage of reclamation.

The aim of this study is the primary assessment of radon hazard of the Zhurinsky fault of the Kuznetsk coal basin, in the territory of the Salair–Altai–Irtysh fold. Soil radon content, radon flux densities, their spatial characteristics and correlations with each other and with other factors were evaluated. We found that soil radon concentration varies within the range of 3599 to 14,413 Bq/m³ (mean value 8766 ± 569.8 Bq/m³), and radon flux density ranges from 23 to 147 mBq·m⁻²·s⁻¹ with a mean value of 67.19 ± 1.31 mBq·m⁻²·s⁻¹. A correlation with air temperature, pressure and humidity was found, which decreases with the depth of the measurements. All studied parameters in space are clustered (p ≤ 0.1). At the same time, the whole studied area in the vicinity of the tectonic disturbance should be classified as radon-hazardous, and residential structures located within its boundaries as potentially hazardous. Our study contributes to understanding the radon hazard of crustal faults.

The main purpose of this study is to assess the radon hazard in areas near the boundary of a coal mine. Our assessment included an analysis of the soil’s radon volume activity (VAR) and radon flux density (RFD), as well as their spatial characteristics and correlations with other factors. The soil VAR varies in the range from 3477.7 to 17,520 Bq/m³ (mean value 9786.9 ± 474.9 Bq/m³), and RFD from 10 to 160 mBq·m⁻²·s⁻¹ with a mean value of 59.76 ± 2.45 mBq·m⁻²·s⁻¹. The RFD parameter is spatially clustered (p ≤ 0.01). No significant differences between RFD and soil VAR were found, both inside and outside the minefield areas (p ≥ 0.05). However, we suggest considering the entire studied space of the minefield boundaries and surroundings to be radon-hazardous. This contributes to the understanding of the radon hazard of coal mines for ground structures both in the mine area and in its surroundings.