The paper presents data on geochemical features of the water-rock system of the Skalinskoye radon water manifestation. The waters of the Skalinskoye manifestation by chemical composition belong to the SO4-HCO3 Na-Mg-Ca type with a total mineralization value of 279–787 mg/dm3. The geochemical parameters of the medium correspond to the oxidizing environment with Eh +84,6…+187,0 mV, pH 6.9–8.8 and O2dissolved concentrations of 3.75–9.93 mg/dm3. Radon activity is up to 572 Bq/dm3. The water-bearing rocks are represented by biotite granites of normal and moderately alkaline series, which are permeated by quartz and sericite-quartz veins. With an increase in the total mineralization of radon waters, the prevailing forms of migration are calcium, magnesium, nickel and strontium bicarbonates, nickel carbonate and magnesium sulfate. Uranium migrates mainly in the form of dissolved hydroxide U(OH)4(aq). According to saturation indices, all waters are saturated in relation to calcite, uraninite and amorphous uranium oxide.

Relevance. The need to dentify the characteristics of the distribution of radioactive elements in the groundwater of Northern Kazakhstan. Aim. Generalization of available data on the geochemistry of groundwater and uranium and radon distribution in them using the example of the northern regions of the Republic of Kazakhstan. Methods. Generalization of long-term hydrogeochemical research and compilation of an electronic data bank on the territory of Northern Kazakhstan. A laboratory study of the chemical composition of groundwater was carried out at the Research Laboratory of Hydrogeochemistry of the School of Natural Resources Engineering of Tomsk Polytechnic University. Measurements of 222Rn contents in waters were carried out using the Alfarad Plus complex in the Laboratory of Hydrogeology of Sedimentary Basins of Siberia, Institute of Geology and Geography, Siberian Branch, Russian Academy of Sciences. Results. The groundwater of aquifers of different ages, distributed in the territory of Northern Kazakhstan (North Kazakhstan uranium province), was studied. Two geochemical sets of groundwater were identified. The first is characterized by the dominance of HCO3– and Mg2+ in the water composition, and the second by Cl– and Na+. A change in composition and an increase in the value of total mineralization from 0,1 to 49 g/dm3, in the direction from north to south, indicate the development of continental salinization. In natural waters of the first group, uranium content varies from 0.065 to 16000 μg/dm3 and radon activity from 4 to 3885 Bq/dm3. For sodium chloride waters of the second set, concentrations can reach 32500 μg/dm3, and radon activity is 6–59 Bq/dm3, since the emanating reservoir (granitoids) is located to the north – at a distance of 80–100 km. Naturally, granitoid massifs of the studied region are sources of uranium. Their drainage by the river network leads to its removal and concentration on geochemical barriers in the groundwater of the Neogene-Quaternary aquifer. This distribution of radioactive elements is associated with the high migration ability of uranium in solution in the form of uranyl ion in oxidizing geochemical conditions.

--We present the first results of comprehensive isotope-geochemical studies of mineral radon waters of the Tulinskoe field (Novosibirsk), aimed at identifying their stages of interaction with the host rocks. By geochemical coefficients Ca/Na, Ca/Mg, Ca/Si, Mg/Si, Na/Si, Si/Na, rNa/rCl, and SO4/Cl, the studied waters are assigned to fracture-vein waters of granitoids. The indices of carbonate mineral saturation of the radon waters show their oversaturation with aragonite, calcite, and dolomite. The waters are also saturated with diaspore, ferrohydrite, gibbsite, and kaolinite, which leads to the deposition of these minerals as secondary phases. In the thermodynamic diagrams, the points of the activities of the radon water components are localized mainly in the stability fields of clay minerals (kaolinite and Na-, Ca-, and Mg-montmorillonites), layered silicates (talc), and zeolites (laumontite). A few points fall in the stability field of silicates (Mg-chlorite). The studied waters of the Tulinskoe field are neutral fresh, with Si = 6.41-9.02 mg/dm3. According to the results of thermodynamic calculations, the radon waters of the Tulinskoe field are in equilibrium with carbonate minerals and hydromicas. Following the classification by S.L. Shvartsev, they are assigned to the Si-Na geochemical type.

The paper presents the first results of studying the radioactivity of water-bearing rocks in a wide stratigraphic range within the Ob-Zaisan folded region. It was found that contents of uranium and thorium in igneous rocks (from the Devonian to the Triassic), on average amount to 9.6 and 17.7 g/t, and 2.5 and 4.6 g/t, respectively in sedimentary rocks (from the Lower Cambrian to the Middle Jurassic). It was determined that igneous complexes of the Kolyvan granitoid massif are most enriched in uranium (up to 65.1 g/t) and thorium (up to 108.8 g/t).

Hydrogeological and hydrogeochemical conditions, the concentrations of major and some minor ions and 222Rn were determined in the Kamenskoye hydro-radon occurrence in the Southern part of West Siberia. Two different aquifer systems were revealed in the hydrogeological section: the Quaternary sediments with pore waters and the Upper Paleozoic granites including the waters of regional fracturing zone and fracture-vein waters. They are located in a common mixing area and are affected by flooding and anthropogenic pollution. Mineral radon fracture-vein waters in granites, not affected by anthropogenic impact, have been revealed in two boreholes. These waters are cool, fresh (TDS 613.4 to 689.9 mg/L) and Si4+ content within a range from 10.3 to 13.6 mg/L. The pH of these waters is neutral to weakly alkaline (6.9-7.8), the gases dissolved in the waters are oxygen and nitrogen. The determined activity of 222Rn varies within the range from 1101 to 1570 Bq/L; 238U concentration varies between 5.6.10- 3-6.5.10- 3 mg/L, while 226Ra ranges from 2.7.10- 9 to 1.8.10-8 mg/L. The relative fractions of cations (Mg2+, Ca2+, Na+, Sr2+, Ba2+) decrease with an increase in TDS value due to the formation of poorly soluble carbonate and sulphate compounds. The forms of Fe(II) are represented by Fe2+, FeHCO3+, FeCO30, and Fe(III) migrates in the forms of hydroxo complexes Fe(OH)2 + and neutral species Fe(OH)30. Manganese migrates mainly as a cation, while other forms (MnHCO3+, MnCO30) are less abundant, and MnSO40, MnCl+, MnOH+ are minor. The chemical forms of nickel and copper migration are free cations, as well as hydrocarbonate and carbonate complexes. Copper, as well as beryllium, also migrate as hydroxo complexes. The forms in which chemical elements migrate and their migration coefficients provide evidence that the equilibrium minerals become more complicated when passing from surface waters (greenalite, siderite, and ferrihydrite and greenalite) to the fracture-vein waters in the Upper Paleozoic granites saturated with dolomite, calcite, talc, magnesite and rhodochrosite.

The first integrated isotope and chemical data on radon-rich waters of the Tulinka aquifers (Novosibirsk, West Siberia) are presented. The Tulinka radon waters are fresh, with neutral to moderately alkaline pH (7.3-7.7), SO4-HCO3 Na-Mg-Ca major-ion chemistry. The amount of total dissolved solids is 720-910 mg/L, Si content 6.41-9.02 mg/L. Eh is within +169.1 - +250.0 mV, corresponding to oxidized conditions. The concentration of dissolved oxygen is 2.86-7.37 mg/L. Radon activity (222Rn) varies from 173 to 276 Bq/L. The concentrations of U, Th, and Ra isotopes are 0.015-0.017 mg/L238U, 9.59 center dot 10-7 to 1.58 center dot 10- 5 232Th, and up to 4.93 center dot 10- 10 226Ra; the 232Th/238U ratio is in the range 5.81 center dot 10- 5 to 9.42 center dot 10-4. Total alpha activity is not higher than 891 mBq/L, and beta activity is 80 mBq/L. The compositions of stable isotopes are-15.4 to - 15.1%0 delta 18O,-114.2 to -112.8%0 delta D, and-13.9 to - 9.9%0 delta 13C. The isotope signatures and recharge patterns of the Tulinka waters are insensitive to seasonal effects, which suggests the slow water exchange. Substantial seasonal variations of the content of dissolved inorganic carbon (DIC) are detected. The range of delta 13CDIC in the analyzed samples (from-14.3 to-9.0%0) corresponds to a mixed CO2 origin: diffusion of soil CO2 approaching the atmospheric delta 13CCO2 values, and biogenic CO2 released by decaying plant residues. The measured isotope characteristics provide evidence that the waters recharge by infiltration from meteoric sources. The approximate radiocarbon age of DIC in the Tulinka waters, determined for the first time, is 2663 +/- 144 years. However, this age may be underestimated due to groundwater mixing with the present-day surface waters.

Исследовано распределение загрязняющих веществ 1 класса опасности и микрокомпонентов в природных водах Новосибирской городской агломерации, где немаловажную роль в загрязнении вод играет не только большое количество транспортных средств, но и промышленных предприятий. Показано, что природные воды в основном гидрокарбонатного кальциевого и кальциево-магниевого состава с величиной общей минерализации от 127 до 910 мг/дм3 и концентрацией кремния 0.14-11.61 мг/дм3. Геохимическая обстановка изменяется от восстановительной (Eh -164.3 мВ) до окислительной (Eh 442.1 мВ), pH 6.9-8.8 с содержанием O2(раств.) 0.48-20.28 мг/дм3. В черте города Новосибирска выявлены превышения фоновых значений по 33 химическим элементам, содержания загрязняющих веществ 1 класса опасности составляют, мг/дм3: для Be (6.4·10-6)-(1.4·10-4), As 0.0003-0.26, Hg (8.33·10-7)-(2.3·10-4), Tl (6.2·10-7)-(8.2·10-5), U (1.3·10-5)-0.21. Активность радона, установленная в природных водах города Новосибирска, изменяется от 1 до 1570 Бк/дм3. Определено, что активному антропогенному воздействию подвержены в основном речные воды Ини, 2-й Ельцовки, Плющихи, Ельцовки, Камышенки и Оби. В подземных водах выявлены большие несоответствия действующим нормативным документам и превышения предельно допустимых концентраций в скважине пос. Кирова (Mn - в 14 раз, Fe - в 10 раз, As - в 5 раз) и в СНТ "Тополь" (Mn - в 59 раз, Fe - в 94 раза, As - в 27 раз). The distribution of the 1st hazard class substances and trace elements in the natural waters of the Novosibirsk urban agglomeration is investigated. A substantial role in water pollution is played in the study area not only by a large number of vehicles but also industrial enterprises. The composition of natural waters is determined as mainly hydrocarbonate calcium and hydrocarbonate calcium-magnesium, with total dissolved solids varying from 127 to 910 mg/dm3, and silicon concentration 0.14-11.61 mg/dm3. The geochemical setting changes from reducing (Eh -164.3 mV) to oxidizing (Eh 442.1 mV), pH 6.9-8.8 with O2(sol.) content 0.48-20.28 mg/dm3. Within the city of Novosibirsk, excesses of background values for 33 elements were revealed; the concentrations of the first hazard class substances are, mg/dm3: Be (6.4·10-6)-(1.4·10-4), As 0.0003-0.26, Hg (8.33·10-7)-(2.3·10-4), Tl (6.2·10-7)-(8.2·10-5), U (1.3·10-5)-0.21. The activity of radon, established in the natural waters of the city of Novosibirsk, varies from 1 to 1570 Bq/dm3. The waters under active anthropogenic load are mainly the river waters of the Inya, the Eltsovka the 2nd, the Plyushchikha, the Eltsovka, the Kamyshenka, and the Ob. In groundwater samples, excesses over the actual normative documents and maximum permissible levels were revealed in the well in Kirov settlement (Mn - by a factor of 14, Fe - 10, As - 5), and in the Topol Gardeners Non-Commercial Partnership (Mn - by a factor of 59, Fe - 94, and As - 27).

Институт нефтегазовой геологии и геофизики им.А.

The geochemical features of 22 deposits and manifestations of radon waters in the south of Siberia (some of them for the first time) are considered. The studied waters are very diverse in terms of gas and chemical composition, total mineralization, geochemical parameters of the environment, and temperature. Three groups of radon waters have been established according to the Eh value: oxidizing conditions, transitional and reducing. Due to the wide variety of waters in terms of chemical composition, some of the studied objects belong to several groups at once, for example, the Choigan natural complex, the Skalinsky, Novobibeevskoye, and Sedova Zaimka manifestations. The concentrations of natural radionuclides are (mg/dm): U (3.68∙10 - 1.40), Th (4.04∙10 - 2.16∙10). The activity of dissolved radon (Rn) varies from 4 to 2257 Bq/dm. The Th/U ratio varies from 2.63∙10 to 26, and its maximal values were detected in ultrafresh, thermal, alkaline waters with reductive geochemical medium in which thorium possesses increased migration capacity. Quite contrary, uranium migrates in the oxidative geochemical setting.

The paper proposes the concept of a regional assessment of the outlooks for implementation of CCUS (carbon capture, utilization and storage) projects at the territory of the Russian Federation. Three groups of criteria are considered: general hydrogeological, tectonic and environmental. For the first time, the categories of lands with high, medium, low prospects and unpromising ones are singled out. A map of the outlooks for the implementation of CCUS projects at the territory of the Russian Federation was compiled according to the criteria of the regional level on a scale of 1: 2500,000 in the form of an ArcGis project, including its interactive analogue with access via the Internet. The performed analysis of the hydrogeological features of the territory of the Russian Federation made it possible to identify 56 structures with high, 6 with medium and 29 with low prospects at the regional stage. The most promising areas are confined to three hydrogeological regions: the East European, East Siberian platforms and the West Siberian Plate.

This study is relevant for obtaining the first geochemical data (including information on radionuclides) on the drainage waters of developed and flooded quarries in the eastern areas of the Novosibirsk Region. The objective of the study was to identify the features of the chemical composition of drainage waters (a wide range of chemical elements from Li to U). The study was carried out by titrimetry, ion chromatography and mass spectrometry with inductively coupled plasma in a laboratory setting at the Hydrogeochemical Problem Research Laboratory (PNIL GGH) of the Engineering School of Natural Resources of Tomsk Polytechnic University (IShPR TPU). Measurements of 222 Rn in waters were carried out at the Alfarad Plus facility of the Laboratory of Siberian Sedimentary Basins Hydrogeology of the A. A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences (INGG SB RAS). The data were divided into homogeneous geochemical populations using the coefficients Ca / Na, Ca/ Mg, Ca / Si, Mg/ Si, Na / Si. The chemical composition of the studied objects was found to be highly diverse. The dominant waters have the chemical formula SO 4 -HCO 3 / Na-Mg-Ca with a TDS (total dissolved solids) of 400 to 700 mg/dm 3 . Three geochemical groups of waters were identified. The first is represented by drainage waters of the developed rubble stone quarries, the second includes facilities of the Gorlovka coal basin, and the third refers to abandoned flooded quarries. The first group is characterized by oxidizing conditions with Eh varying over a wide range from +84.6 to +261.0 mV, pH from 6.9 to 8.6, and O 2disso i ved from 3.43 to 14.39 mg/dm 3 . The radionuclide concentrations are (mg/dm 3 ): 238 U 9.30 • 10 -3 - 1,40; 232 Th 1,00 • 10 -6 - 2,16 • 10 -3 ; 222 Rn activity varies from 1 to 572.5 Bq/dm 3 . The 232 Th / 238 U ratio ranges from 4.20 • 10 -5 to 2.69 • 10 -3 with an average of 8.40 • 10 -4 . The second group has a smaller Eh variation range of +133.2 to +199.6 mV, pH from 7.5 to 8.5, and O 2dissolved from 6.81 to 10.43 mg/dm 3 . The radionuclide concentrations vary in the following ranges (mg/dm 3 ): 238 U 2.26 • 10 -3 - 2.90 • 10 -2 ; 232 Th 7.5 • 10 -6 - 5.57 • 10 -4 . The 232 Th / 238 U ratio ranges from 8.37 • 10 -4 to 4.80 • 10 -2 at an average of 9.54 • 10 -3 . The third group is also characterized by an oxidizingizing geochemical environment with Eh +131.3 - +250.0 mV, pH from 6.9 to 8.8 and O 2dissolved from 4.00 to 16.59 mg/dm 3 . The radionuclide concentrations are (mg/dm 3 ): 238 U 3.00 • 10 -4 - 2.74 • 10 -2 ; 232 Th 1.65 • 10 -6 - 1.15 • 10 -5 ; 222 Rn activity varies from 2 to 31 Bq/dm 3 . The 232 Th/ 238 U ratio ranges from 2.36 • 10 -4 to 1.02 • 10 -3 at an average of 6.25 • 10 -4 . Overall, the 232 Th / 238 U ratio of the studied waters indicates their uranium nature of radioactivity. The data obtained indicate a slight impact of the drainage water discharge from the abandoned quarries on the environment.

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/dm(3)). 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/dm(3) and a silicon content of 4.1-8.6 mg/dm(3). 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-2dissolv. = 6.24-12.26 mg/dm(3). The revealed predominance of SO42- 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 alpha-activity of waters is 3-4 mBq/dm(3), and gross beta-activity is 11-15 mBq/dm(3). Natural radionuclides are found in the spring waters within the following limits (mg/dm3): U-238, from 2.83 center dot 10(-3) to 4.13 center dot 1(0-)3; Th-232, from 2.39 center dot 10(-6) to 1.16 center dot 10(-5), and Ra-226, from 3.83 center dot 10(-10) to 4.93 center dot 10(-10). The value of the Th-232/U-238 ratio for the waters ranges from 5.79 center dot 10(-4) to 3.61 center dot 10(-3), as a result of the oxidative geochemical migration-arresting capability of thorium. The uranium isotope ratio (gamma) U-234/U-238 varies from 2.6 to 3.2 for the waters, with the uranium isotope activity determined as 117-124 mBq/dm(3) for U-234 and 38-48 mBq/dm(3) for U-238. This indicates shallow circulation of the studied waters as compared with those of the Svyatoi spring in Verkh-Tula Village, for which gamma = 1.3; the U-234 activity, 147 mBq/dm(3); and the U-238 activity, 115 mBq/dm(3). By isotopic composition, the origin of the spring waters is assigned to the infiltration type, and they are characterized by relatively narrow distribution of delta O-18 (from -17.5 to -16.7 parts per thousand) and delta D (from -128.4 to -126.2 parts per thousand) values. The delta(CDIC)-C-13 values are from -10.3 and -10.9 parts per thousand in springs 3 and 2 and become lighter (-11.2 and -12.1 parts per thousand) 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 delta O-18 and delta D data and C-14 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: delta(13). varies within narrow limits (from -3.1 to -2.7 parts per thousand), and delta O-18 varies from 17.2 to 18.4 parts per thousand. The isotopic composition becoming lighter for carbon (up to -11.0 parts per thousand) and oxygen (up to 13.9 parts per thousand) 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.

Актуальность исследования заключается в получении актуальных изотопно-геохимических данных о природных водах и вмещающих горных породах проявления радоновых вод Седова Заимка. Цель: изучить особенности химического состава природных вод и водовмещающих пород и получить первые сведения по активности 222Rn и изотопному составу δD, δ18O, δ13С, 234U, 238U, 226Ra и 228Ra. Методы. Лабораторное изучение химического состава методами титриметрии, ионной хроматографии, масс-спектрометрии с индуктивно связанной плазмой проводилось в ПНИЛ гидрогеохимии ИШПР ТПУ. Определение комплекса величин δD, δ18O, δ13СDIC вод и растворенного неорганического углерода (Dissolved Inorganic Carbon (DIC)) проводилось в центре коллективного пользования ИГМ СО РАН с помощью прибора Isotope Ratio Mass Spectrometer FinniganTM MAT 253, снабженного приставками пробоподготовки H/Device (для определений δD) и GasBench II (для определений δ18O и δ13СDIC). Измерение содержаний 222Rn в водах проводилось на комплексе «Альфарад плюс» в лаборатории гидрогеологии осадочных бассейнов Сибири ИНГГ СО РАН. Данные по общей β-активности вод, а также активностях 234U, 238U, 226Ra и 228Ra получены после предварительной радиохимической пробоподготовки на альфа-спектрометре ALPHA-ENSEMBLE-8 (Ametek, ORTEC, США); гамма-спектрометрической системе, скомпонованной на базе колодезного коаксиального HPGe ППД с низкофоновым криостатом EGPC 192-P21/SHF 00-30A-CLF-FA фирмы EURISYS MEASURES (Франция) и альфа-бета радиометре для измерения малых активностей УМФ-2000 с кремниевым детектором (НПО «Доза», Россия). Разделение данных на однородные геохимические совокупности выполнено с помощью коэффициентов Са/Na, Са/Mg, Ca/Si, Mg/Si, Na/Si. Для выявления степени концентрирования химических элементов в природных водах были рассчитаны коэффициенты концентрации  и водной миграции (по А.И. Перельману) . Результаты. Открыто проявление радоновых вод Седова Заимка, и впервые выполнены комплексные изотопно-геохимические исследования. Радоновые воды (активность 222Rn до 428 Бк/дм3) в основном характеризуются HCO3 Mg-Na-Ca составом с величиной общей минерализации от 158 до 581 мг/дм3 и содержанием кремния от 4,34 до 30,84 мг/дм3. Геохимические параметры среды варьируют от восстановительной до окислительной обстановки с величинами Eh от –40,2 до +28,4 мВ; pH от 7,5 до 7,6 и O2раств. от 2,99 до 5,24 мг/дм3. Значения геохимических коэффициентов составляют: Ca/Na 77,17; Ca/Mg 6,63; Ca/Si 11,42; Mg/Si 1,48; Na/Si 0,92; Si/Na 15,34; rNa/rCl 2,12; SO4/Cl 4,02, что закономерно указывает на процессы формирования химического состава радоновых вод во вмещающих породах преимущественно алюмосиликатного состава. Среди микрокомпонентов наиболее высокими средними содержаниями выделяются (мг/дм3): Si=17,77; Fe=1,18; Mn=0,16; Zn=0,020 и W=0,0036. Значимых коэффициентов концентрации микрокомпонентов не выявлено. Сильной миграционной способностью в растворе обладает Sr, средней – Si, Mn, Ba, Cs и U. Суммарная β-активность вод составляет 32 мБк/дм3. Содержания природных радионуклидов варьируют (мг/дм3): 238U от 3,91∙10–4 до 6,39∙10–4; 232Th от 6,02∙10–6 до 2,37∙10–5 и 226Ra от 6,66∙10–11 до 1,09∙10–10. 232Th/238U отношение в водах изменяется от 1,02∙10–2 до 3,71∙10–2, что является следствием окислительной геохимической обстановки, в которой торий не мигрирует. Уранизотопное отношение (γ) 234U/238U составляет 5,75 при активности изотопов урана (мБк/дм3): 234U (115±7), 238U (20±2), что указывает на неглубокую циркуляцию изученных вод. Активность изотопов радия в водах равна у 226Ra 70±7, а у 228Ra 51,8±3,9 мБк/дм3. Отношение 226Ra/228Ra в HCO3 Mg-Na-Ca радоновых водах составляет 1,35. Изотопный состав радоновых вод (от –126,3 до –121,1 ‰ для δD и от –16,8 до –16,3 ‰ для δ18O) указывает на их метеорно-инфильтрационное происхождение. Изотопный состав углерода δ13CDIC указывает на биогенное происхождение углекислоты и ее участие в процессе карбонат-силикатного выветривания пород.

The purpose of the work is to carry out integrated isotope-geochemical studies of the mineral waters of the Belokurikha deposit. The methods of titrimetry, ion chromatography, inductively coupled plasma mass spectrometry (ICPMS) have been used in the laboratory investigation of the chemical composition of waters. The isotope composition of oxygen, hydrogen and carbon in dissolved carbon dioxide has been studied with the help of the Isotope Ratio Mass Spectrometer FinniganTM MAT 253 equipped with the attachments for sample preparation H/Device (to analyze the δD ratio) and GasBench II (to analyze δ18O and δ13СDIC ratios). There are two aquifers at the deposit. The first nonartesian aquifer comprises loose sediments of the Quaternary age. The second artesian aquifer includes the granites of the upper Paleozoic age with the different fracture degree: from monolith to loosened. Three groups of waters are distinguished on the basis of geochemical coefficients: fracture-vein waters bedded in weathered granites; groundwaters of the zone of rare earth mineralization and background composition; surface waters of the Belokurikha river. The isotope data on oxygen and hydrogen provide evidence that the production aquifers of the Belokurikha field are fed through the infiltration of meteoric waters, with the feeding shift to winter precipitation. The paper provides the first data of the integrated isotope-hydrogeochemical studies of nitric-siliceous low-radon thermal waters of the Belokurikha deposit. The composition of these waters is HCO3-SO4 Na and SO4-HCO3 Na with the total dissolved salts value ranging from 198 to 257 mg/dm3. The waters are characterized by alkaline pH of 8.6–9.6, silicon content ranging from 19.8 to 24.6 mg/dm3, and they are referred to the fracture-vein waters of the Upper Paleozoic granites. 222Rn activity is up to 359 Bq/dm3. The ratios of δD (from -126.9 to -102.7 ‰) and δ18O (from -17.5 to -14.2 ‰) in the studied waters indicate their atmospheric origin. The values of δ13СDIC vary from -9.7 to -25.6 ‰ and point to the biogenic origin of carbon.