This work is devoted to the investigation of rare-metal granites associated with anorthosite–rapakivi granite rock complexes. This article evaluates the physicochemical conditions that governed the formation of a rare-metal granite dike. It also explores assumptions regarding the geological characteristics of the magmatic chamber, describes evidence for liquid immiscibility, and addresses the post-entrapment evolution of hydrosilicate liquids. In addition, new mineralogical data are presented. The methods employed include optical and electron microscopy, Raman spectroscopy, secondary ion mass spectrometry, laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS), melt inclusion homogenisation experiments, and fluid inclusion study. The investigated granitic dike formed under low pressure (60–110 MPa) and temperatures of about 580–600 °C, from a specific volatile-saturated magma rich in H2O (up to 16.76 wt% in quenched hydrosilicate liquid products) and in F (up to 4.16 wt%) and Li (up to 3804 ppm), as indicated by homogenised melt inclusions. At the time of emplacement, a silicate melt, a probable Ca-fluoride melt, an Mg-Fe Al-Si-rich hydrosilicate liquid (either mutually soluble with or mixed with the inferred Ca-fluoride melt), and an essentially aqueous fluid coexisted. Depolymerisation of the silicate melt and the presence of complex ions probably promoted the dissolution and transport of high field strength elements (HFSE) and large ion lithophile elements (LILE) elements by the Mg-Fe Al-Si-rich hydrosilicate liquid. During the final stage of evolution of the granitic magmatic system, Mg behaved incompatibly because of its negligible partitioning into mica; rather than accumulating in the silicate melt, it entered the hydrosilicate liquid as a major component. The residual silicate melt consequently attained even lower Zr/Hf, Nb/Ta, and Y/Ho ratios than the studied rock.

Natural water is one of the most vulnerable to anthropogenic impact among environmental components. It undergoes the negative impact of the development of mineral deposits not only during the exploitation period, but also for a long time after its completion. In general, the chemical composition of natural waters can be considered as a result of the interaction in the water- rock-organic matter system. A large number of factors influences on the accumulation of pollutants in natural waters: temperature, water-rock ratio, water exchange in the system, which in other words can be called the time of water-rock interaction, etc. Besides of many factors, there are two main processes of formation of the chemical composition of natural waters: dissolution-precipitation of minerals and complexation-ionization. This paper focuses on the behavior of chemical elements that are potentially toxic to humans and animals: Fe, Ni. Cu, Zn, Pb, As. The contents of Ca, Mg, Na, K, Fe, S were determined by ICP-AES; the contents of Ni, Cu, Zn, Cd, Pb, As and other trace elements were analyzed by ICP-MS. The components of carbonate equilibrium were determined by potentiometric titration. The content of Cl- was measured by ion chromatography. Mineral composition of dump rocks was determined by scanning electron microscopy. The elemental composition of rocks was determined by X-ray fluorescent analysis. Equilibrium-kinetic modeling was used to study dissolution-precipitation of minerals. Equilibrium thermodynamic modeling was applied to analyze the complexation-ionization processes. The main sources of studied toxic elements are sulfide minerals (pyrite, chalcopyrite, sphalerite, galena). Equilibrium-kinetic modeling showed that the main mechanism of toxic element intake is the oxidative dissolution of sulfide minerals. In the classical case, this process leads to the formation of acid drainage. In our case, acid drainage is not formed due to the low content of sulfide minerals in the rocks, as well as the neutralizing effect of carbonate dissolution. However, despite neutral pH levels, heavy metals enter the solution and in some cases accumulate in significant concentrations. The growth of toxic element concentrations was inhibited by formation of secondary mineral phases. In our case, formation of secondary goethite and smithsonite was shown by computer equilibrium-kinetic modeling. Arsenic enters natural waters due to the dissolution of loellingite. It does not form its own secondary mineral phases and accumulates linearly over time. The process that restrains the precipitation of secondary minerals is the complexation of metals with organic matter. Iron has the strongest affinity to organic matter among considered elements, so the presence of organic ligands in the system determines its behavior. In the case of low organic matter content in natural waters, Fe coming due to the dissolution of minerals is not retained in solution, but precipitated as goethite. In case of high organic matter content, formation of stable organomineral complexes occurs and Fe accumulates in the solution. Calculations showed that under high organic matter content and low Fe content in solution, Zn and Cu also form complexes with organic ligands. Probably, higher levels of Zn and Cu accumulation in waters occur due to runoff from dumps to the wetland, where natural waters have an exceptionally high content of organic matter.

New data on dikes of rare metal topaz–“zinnwaldite” granites of the Salmi anorthosite–rapakivigranite complex are presented. The U–Pb (ID-TIMS) isotopic age of Ta–Nb mineralization: the columbite-(Fe)–tantalite-(Fe) series and tapiolite is 1541 ± 2.5 Ma. Conclusions are given on the age limitations of associated rocks, intersected by analogous dikes, and the discreteness of the rare-metal magmatism manifestation in the studied area.

AIM:To evaluate the automated medical decision support system "Sechenov.AI_nephro" in the treatment of patients with renal parenchymal tumors. MATERIALS AND METHODS:The beta version of the web-platform "Sechenov.AI_nephro" consists of a neural network based on MONAI (Medical open network for AI) and a web interface, with algorithms classified based on segmentation data in manual mode using the 3D modeling program "Amira". A total of 441 patients with renal parenchymal tumors were included in the multicenter prospective study. Testing was carried out over 12 months in 3 urological centers: 358 (81.2%) patients from I.M. Sechenov First Moscow State Medical University, Moscow; 73 (16.6%) patients from Bashkir State Medical University; and 10 (2.3%) patients from Saratov State Medical University named after V.I. Razumovsky. In all cases, contrast-enhanced computed tomography (CT) was performed preoperatively. DICOM (Digital Imaging and Communications in Medicine) data of each patient's CT was uploaded to the web-platform "Sechenov.AI_nephro" for automatic construction of a 3D model of the tumor. The work of the web-platform "Sechenov.AI_nephro" was evaluated based on a questionnaire completed by surgeons who performed the surgical intervention. The questionnaire consisted of 14 questions, with a scoring system from 1 to 10 points. It was divided into 3 main sections, including first for assessment of the quality of work of the web-platform "Sechenov.AI_nephro"; second for evaluation of the use of the 3D model in communication with the patient, for surgical planning and intraoperative navigation; and third for analysis of the choice of useful data display mode, errors in constructing the 3D model. RESULTS:The questionnaire was completed in 253 (57.37% of 441) cases. The quality of 3D models was rated 7.8-9.4 points, and the use of the 3D model in communication with the patient, for surgical planning and intraoperative navigation was rated 7.8-9.4 points. The 3D models were constructed correctly in 70% of cases. The area of interest was the useful mode of 3D models display in surgical planning. Incorrectly constructed anatomical elements were veins in 25.5% and the tumor in 26.4% of cases, respectively. CONCLUSION:The automated medical decision support system in the treatment of patients with renal parenchymal tumors "Sechenov.AI_nephro" demonstrated satisfactory quality of 3D reconstruction of pathological process. 3D models allow for personalized determination of the surgical tactic for treating patients with renal tumors.

The Beck mine, located in the Republic of Karelia, Russia, is an abandoned mining site with significant potential for environmental contamination due to the presence of potential pollutants in its waste rocks. In this study, we investigated the chemical composition of mine waters and waste rocks and developed a theoretical model to understand waterrock interactions and the release of potential pollutants. Water samples collected from various locations on the Beck mine property were analyzed for chemical composition and showed low concentrations of total dissolved solids with pH values ranging from 6.42 to 7.74. The chemical composition of natural waters was determined by ICP-MS, ICP-AES, ion chromatography, potentiometric titration, and spectrophotometry. Equilibrium kinetic modeling was used to simulate water-rock interactions. The model predicted the concentrations of major and trace elements, demonstrating that dissolution-precipitation and complexation are the primary mechanisms shaping the chemical composition of mine waters. The dynamics of dissolution-precipitation of Fe-containing minerals highlighted the importance of the duration of water-rock interaction, with stagnant mine waters exhibiting higher concentrations of heavy metals. In addition, the presence of dissolved organic matter played a critical role in the accumulation of iron and arsenic in the studied mine waters. Overall, this study highlights the utility of equilibrium kinetic modeling in understanding the behavior of heavy metals during water-rock interactions and provides valuable insights into the potential environmental impacts of abandoned mine sites such as the Beck mine.

The speciation of chemical elements in the waters and its dependence on the dissolved organic matter were studied by a complex of methods, involving thermodynamic calculations and experimental fractionation. The waters were studied at the abandoned and flooded Herberz Mine in the Pitkäranta district, Karelia, Russia. The regional natural waters are typically highly humified. In combination with the unique metallogeny of the rocks, this makes the mine suitable for solving the formulated problems. The eastern shaft of the Herberz Mine was sampled to a depth of 20 m to trance the changes induced by changes in the redox conditions. One of the geochemical characteristics of the waters is their relatively high concentrations of trace elements and a low salinity (TDS, total dissolved solids). All water samples from the Herberz Mine contain elevated concentrations of Zn, Fe, Mn, Cu, Ni, As, and W. Experimental fractionation and thermodynamic simulations of the speciation of chemical elements led us to identify metals whose accumulation most strongly depends on organic matter (OM). Both methods have demonstrated that U, Th, Cu, Ni, and Y show a high chemical affinity to OM. Metals (Cd and Fe) weakly bonded to the functional groups of natural OM, with the predominance of electrostatic bonding and a higher proportion of carboxyl bonds, are most susceptible to transformations with changes in geochemical conditions.

In the mining industry, one of the principal issues is the management of the waste generated during ore concentration, which represents a potential source of environmental pollution. The most acute issue originates from the mining heritage in the form of dumps formed of mining tailings that were created before the introduction of waste storage standards and may be located in urban areas. This research investigated this problem using the example of the tailings dump “Krasnaya Glinka”, located in a residential area of Pitkäranta (Karelia, Russia) in close proximity to the shoreline of Lake Ladoga. A complex approach, including the investigation of the natural water of the study area and tailings material and an experiment simulating the interaction of this material with atmospheric precipitation, allowed us to obtain the first data on the current status of the tailings dump and its surroundings and to identify environmental pollutants. This research used XRF, XRD, and EPMA analytical methods for assaying the tailings materials obtained from the dump and ion chromatography, potentiometric titration, ICP-MS, and AES for the water samples. The results show the influence of the tailings dump’s materials on the formation of the environmental impact—in the water from the area of the tailings dump, increased concentrations of chalcophilic elements are observed, for example, Zn up to 5028 µg/L. Based on this study of the tailings dump’s materials and the conducted experiment, an attempt is made to connect the chemical compositions shown in the natural water data with the specific mineral phases and processes occurring during supergene transformations in the tailings storage. As a result of the conducted research, it was found that despite more than 100 years of exposure of the tailings materials under natural factors, mostly atmospheric precipitation, equilibrium with the environment has not come. The processes of extracting toxic elements and carcinogenic mineral phases into the environment are continuing. In the process of studying the tailings materials, it was found that they are probably of economic interest as a technogenic source of W and Sn due to the contents of these components exceeding industrially significant values in the exploited fields.

Actual analytical methods make it possible to precisely determine a of chemical elements contained in water, including for the purpose of assessing the ecological state of the environment in connection with mining activities. The object of this research is the natural waters of the gold deposit “Novye Peski” located in the Pryazhinsky region (Republic of Karelia, Russia). Analytical data indicate that the geochemical background of the region is exceeded for most of the chemical elements. Research results indicate that the geochemical background of the region is exceeded for most of the considered chemical elements and ions, which can be divided into three groups: 1) the highest concentrations were determined in quarry water (Zn, As, Mo, U, Ni, Cu, Sr, Li, B, as well as Ca 2-); 2) the content is at the same level in all and other cations, HCO3samples (Al, Si, V, Ti, Ba); 3) the highest content in stream and tailing pond (Fe, Mn). We assume that the main factor influencing the behavior of elements of the first group is mining, and for the third is the presence of dissolved organic matter high content with the formation of metal-organic species in water.

The problem of the world-class PGE-Cu-Ni Norilsk deposits’ origin has attracted geologists for several decades. The main goal of this study is to determine the specific features of ore-bearing intrusions in comparison with thousands of similar barren intrusions widespread within the Siberian igneous province, and to establish their genesis. As a result of statistical processing of previously published isotope-geochemical data and obtained by the authors, systematic differences were found in the distribution of the isotopic ratio of Nd in ore-bearing and barren intrusions, as well as in volcanic rocks at the Norilsk region. Thus, ore-bearing rocks in ten deposits (Talnakh, Kharayelakh, Norilsk 1, South-Maslovsky, North-Maslovsky, Norilsk 2, Chernogorsky, Zub-Mrksheydersky, Pyasino-Vologochansky, Imangdinsky), different in Ni and PGE reserves, show a very narrow range of Nd isotopic ratio, ԐNd(T) = 1.0 ± 1.0 (2σ, N = 139), whereas barren and volcanic rocks are characterized by a rather wide ԐNd(T) range, from −10 to +7 units (N = 256). Furthermore, ore-bearing intrusions are characterized by reduced and compact variations of the La/Lu ratio due to lower concentrations of light lanthanides. For the first time the authors studied two new intrusions penetrated by MD-48 and MD-60 boreholes drilled by Norislkgeologia LLT at the eastern part of the Mikchangda area. Their economic values are still unclear and should be estimated using geochemical methods. Both intrusions lie in the Devonian rocks, have similar thickness and mineral composition, but differ in textural and structural features, which indicate a rapid crystallization of the MD-48 intrusion. According to the contents of the major oxides, the rocks in MD-48 and MD-60 are identical, but they differ in U/Nb, La/Sm, and Gd/Yb ratios. It is important that the rocks in the MD-60 borehole are characterized by ԐNd(T) = 1.0 ± 0.6 (2σ) and fall into the range of ore-bearing intrusions, whereas the rocks in MD-48 have ԐNd(T) 2.4 ± 0.9, and, thus, are outside of ore-bearing intrusions. Therefore, ԐNd(T) values can be used as a local criterion for the estimation of economic potential of mafic intrusions, which is demonstrated for the Mikachangda area.

The Siberian Traps are believed to play an essential role in the Permian–Triassic extinction event, although the link between these events is unclear. Plume ascent, its interaction with the lithosphere, and crustal rocks are considered as sources of volatile components that trigger mass extinction. Reliable estimations of the volumes of gases released during the basalt magma degassing that formed typical traps are few. In this work, the volatile contents in the parental melt of the Southern Maslovsky intrusion, which is a part of the PGE–Cu–Ni Maslovsky deposit in the Norilsk district in the Northwest Siberian Platform, were determined. The studied intrusion belongs to the ore-bearing Norilsk intrusive complex, which is coeval to the Morongovsky–Mokulaevsky Formations of the Siberian flood basalt province. The objects of this study were 8 silicate-melt inclusions in olivines from picritic gabbro-dolerites and 68 inclusions in clinopyroxenes, and 2 inclusions in olivines from olivine-bearing gabbro-dolerites. The composition of the parental melt in terms of major and trace element abundances was close to the main stage of the platform magmatism. The average volatile contents in melt inclusions were as follows: 4500 ppm H 2 O and Cl 1333 ppm, followed by trace amounts of F 387 ppm, S 743 ppm, CO 2 1279 ppm, and B 4.18 ppm, typical of within-plate magmas. In addition, the contacts of igneous rocks with sedimentary deposits (carbonate-terrigenous rocks and coals) demonstrate the occurrence of narrow zones of alteration and the absence of a significant volume of gases that could influence the process of species extinction. There is no strict evidence of the influence of the Siberian traps on the Permian–Triassic mass extinction.

The origin of the anorthosite-rapakivi granite-bearing rock complexes was a topic of research for geologists for more than a century. Magmatic systems that produce these complexes were widely developed in the Precambrian and have no direct analogues in modern times. The main goal of this study was to characterize the conditions under which primitive granitoids formed and to shed light on the history of ore matter transport during these stages. The object of the research was granite porphyry dikes—a subeffusive analogue of rapakivi granite from the Salmi batholith in the Fennoscandian Shield. Characteristic solid-phase inclusions of a mineral paragenesis of mafic rocks, as well as inclusions of sulfide melts, were found in zircon from this type of rock. These sulfide inclusions were homogenized by heating, and subsequently, the trace element composition was determined by the LA-ICP-MS method. The geochemistry of zircons was studied by the SIMS method, and the temperature of their formation was determined using a Ti-geothermometer. The temperature of the studied zircon grain formation varied from 925 to 765 °C. The values of ƒO2 for the early stages of the rock formation were in the region below the boundary of the FMQ buffer. The presence of two sulfide melts at the time at which the sulfide inclusions were captured by the zircon, pyrrhotite-chalcopyrite, and sphalerite-chalcopyrite compositions was established. The capture of sulfide inclusions from the pyrrhotite-chalcopyrite composition occurred above 841 °C, while in sphalerite-chalcopyrite, they occurred at a lower temperature of 765 °C. The connection between the formation of granite porphyry with mafic melts that form rocks of the gabbro and anorthosite types was established.

AIM:To evaluate the possibilities of textural analysis of 3D models in differentiating the degree of nuclear dysplasia of the clear cell renal cell carcinoma (ccRCC).MATERIALS AND METHODS:The specimens after surgical treatment of 190 patients with ccRCC were analyzed. In all cases, nephron-sparing surgery (NSS) was performed through laparoscopic access. The clinical characteristics were evaluated, including age, gender, tumor localization (side, surface and segments), absolute tumor volume, Charlson comorbidity index, body mass index, nephrometry scores (RENAL, PADOVA, C-index). Patients were divided into 2 groups. In group 1, there were 119 patients with the ccRCC of Grade 1 or 2, while group 2 consisted of 71 patients with ccRCC of Grade 3 and 4. All patients underwent 3D virtual planning of procedure using the 3D modeling program "Amira". At the first stage, two experienced radiologists performed manual segmentation of 3D models of kidney parenchyma tumors. At the second stage, the tumor shape was analyzed with a mathematical calculation of three indicators and more than 300 textural features of statistics of types 1-2 were extracted. Further, an intellectual analysis was carried out. For the evaluation of tumor grade according to Furman system, the classification problem was solved using the machine learning algorithm Stochastic Gradient Descent and cross-validation k=5.RESULTS:The accuracy of classification for the two groups of Grade 1 or 2 and Grade 3 or 4 on the F1 metric was 72.2. To build the model, the following parameters were selected: the absolute tumor volume, the Charlson comorbidity index, "Energy", the first quartile and the second decile of the pixel intensity distribution.CONCLUSION:The texture analysis of 3D models for the prediction of Fuhrman grade in ccRCC demonstrated satisfactory quality for two groups of Grade 1 or 2 and Grade 3 or 4 nuclear dysplasia.

The relevance of the research is related to the need for a regional assessment of the impact of the building stone deposits development on the natural waters of the Northern Ladoga region. The study area is part of the Ladoga Lake catchment basin, the preservation of the superior water quality is a crucial issue. Currently, the lake resources are used in household and industrial water supply, as well as in fish farms and agriculture.The main aim of the research is to investigate the chemical composition and identify the main features of the behavior of chemical ele-ments in the natural waters of building stone quarries. Objects: natural waters and rocks of building stone quarries in the Pitkaranta area of the Republic of Karelia.Methods. Water chemistry was analyzed by means for a set of methods: potentiometric titration, ion chromatography, atomic emission spectroscopy and mass spectrometry. The mineral composition of the rocks was determined using an electron microscopy and powder X-ray diffraction. The mobility of chemical elements was assessed by coefficients of water migration (Kx) according to A.I. Perelman. The speciation of chemical elements in natural waters were calculated using the HCh software package. Results. The considered waters are fresh neutral or slightly alkaline with HCO3 Ca, SO4-HCO3 Na-Ca or HCO3 Na-Ca types. An analysis of a wide range of chemical elements made it possible to determine that S, Ca, Mg, As, Mo, U, Re have the highest mobility in the studied waters. The sources of easily mobile and mobile metals are sulfide minerals and feldspars. According to the thermodynamic calculations dominating species for Zn, Cd, Ni, Co, Sr, Rb, Ba, and Cs are ionic species, for Cu are carbonate species, and for Pb are carbonate and hydroxyl species. The main species of U are carbonate complexes. The water of Ladoga Lake differs in lower salinity and pH value from quarry waters, lower metal contents, which are more typical of being in ionic species. The coefficients of water migration are similar in the studied samples. However, the Kx elements curve of Ladoga Lake is different from the quarry ones. This is explained by the overlap of a number of factors and processes that form the water chemistry of such a large lake. Quarry waters are characterized by enrichment with some trace elements, especially U, Li, Mo, Re, as interaction time and the rock-water ratio increase.

Ссылка для цитирования: Сидкина Е.С., Торопов А.С., Конышев А.А. Геохимические особенности природных вод карьеров строительного камня Питкярантского района (Карелия)// Известия Томского политехнического университета. Инжиниринг георесурсов. – 2023. – Т. 334. – № 4. – С.7-21. Актуальность исследования связана с важностью региональной оценки воздействия разработки месторождений строительного камня на природные воды северного Приладожья. Сохранение высокого качества воды Ладожского озера, в площадь водосбора которого входит район исследований, является критически важной задачей ввиду активного использования ресурсов озера в хозяйственно-бытовом и производственном водоснабжении, а также рыболовстве, сельском хозяйстве. Цель: изучить химический состав и выявить основные особенности поведения химических элементов в природных водах карьеров строительного камня. Объекты: природные воды и горные породы карьеров строительного камня Питкярантского района Республики Карелия. Методы. Химический состав природных вод определяли с помощью набора методов: потенциометрическое титрование, ионная хроматография, атомно-эмиссионная спектрометрия и масс-спектрометрия. Минеральный состав пород определен с помощью электронной микроскопии и порошковой рентгеновской дифракции. Оценка подвижности химических элементов проводилась по коэффициентам водной миграции (Kx) по А.И. Перельману. Формы нахождения химических элементов в природных водах рассчитаны в программном комплексе HCh. Результаты. Все изученные воды являются пресными нейтральными или слабощелочными HCO3 Ca, SO4-HCO3 Na-Ca или HCO3 Na-Ca. Анализ широкого спектра химических элементов позволил определить, что наибольшей подвижностью в рассматриваемых водах обладают S, Ca, Mg, As, Mo, U, Re. К легко подвижным и подвижным относятся металлы, источниками которых являются сульфидные минералы и полевые шпаты. Согласно термодинамическим расчетам доминирующей формой нахождения Zn, Cd, Ni, Co, Sr, Rb, Ba и Cs является ионная, Cu – карбонатная, а Pb – карбонатная и гидроксильная. Основные формы нахождения U представлены карбонатными комплексами. Вода Ладожского озера отличается от карьерных вод меньшей минерализацией и величиной pH, более низкими содержаниями металлов, для которых в еще большей степени характерно нахождение в ионной форме. Коэффициенты водной миграции в целом схожи во всех изученных пробах, однако профиль Кх для Ладожского озера несколько отличается от карьерных. Это объясняется наложением факторов и процессов, формирующих химический состав вод такого крупного озера. Для карьерных вод характерен рост концентраций некоторых микроэлементов, в особенности U, Li, Mo, Re, с увеличением времени взаимодействия и соотношения порода–вода.

Ссылка для цитирования: Химический состав вод малых водотоков Кугдинского массива и его обрамления (Восточная Сибирь) / E.А. Солдатова, А.С. Торопов, Е.С. Сидкина, А.А. Конышев, И.С. Иванова // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2022. – Т. 333. – № 3. – С. 111-125. Актуальность. Активное освоение арктических территорий, а также вопросы, связанные с глобальными изменениями климата, последние несколько десятилетий привлекают внимание ученых из области наук о Земле к исследованию природных особенностей арктических и субарктических территории России. В северной части Восточной Сибири расположены выходы интрузивных массивов, представляющие собой интерес ввиду перспективности разработки полезных ископаемых. При этом континентальные водные системы этой территории остаются малоизученными. Это связано в большей степени с труднодоступностью данных мест и практически полным отсутствуем инфраструктуры. Исследование состава вод интрузивных массивов является интересной задачей не только с точки зрения объяснения процессов формирования химического состава вод арктических территорий, но также может использоваться для совершенствования методики гидрогеохимических поисков месторождений полезных ископаемых. Цель и объект. Объектом исследования в данной работе являются природные воды Кугдинского ультраосновного-щелочного интрузивного массива, который расположен в западной части Анабарского плато. Целью исследования было изучить химический состав вод поверхностных водотоков, дренирующих непосредственно породы интрузивного массива и зону его обрамления, а также провести их сравнительный анализ с крупными реками региона и выявить закономерности формирования химического состава. Методы. В ходе полевых работ, проведенных в июле–августе 2020 г., были отобраны три пробы воды в пределах Кугдинского массива и его обрамления: поверхностные водотоки, дренирующие Кугдинский массив и ручей, приуроченный к доломитам обрамления. Компоненты карбонатной системы определяли методом потенциометрического титрования, а анионный состав – методом ионной хроматографии. Концентрация растворенного органического углерода определена методом высокотемпературного каталитического окисления. Элементный анализ воды был выполнен методами ICP-AES и ICP-MS. Пробы на элементный анализ были отфильтрованы через мембранный фильтр из полиэфирсульфона с размером пор 0,45 мкм в химически чистые пробирки объемом 15 мл с консервацией 0,45 мл HNO3 осч. Результаты и выводы. Катионный состав вод щелочного массива и зоны карбонатного обрамления хорошо отражает состав дренируемых ими пород, в то время как их анионный состав контролируется более сложным комплексом как геохимических (включающих не только состав пород, но и их взаимодействие с органическим веществом), так и гидрологических (особенности питания водотоков) факторов. Сравнение химического состава вод малых водотоков Кугдинского массива и его обрамления с водами средних и больших рек региона показало, что особенности катионного состава выражаются в доминирующей роли магния, а также в повышении доли калия по сравнению с натрием. Анионный состав малых водотоков однороден, резко преобладает гидрокарбонат-ион, в отличие от крупных рек, где повышается доля сульфат и хлорид-иона. Содержания микрокомпонентов в поверхностных водах, дренирующих Куглинский массив и зону карбонатного обрамления, показывают, что потенциально состав вод в пределах данной территории может быть использован как поисковый признак. В водах Кугдинского массива и его обрамления накапливаются такие рудные элементы, как Ni, Zn, Rb. Согласно рассчитанным значениям коэффициента водной миграции преимущественно выносятся из пород Ni, Cu, Zn, Rb, Ag, Pb. По содержанию микрокомпонентов в водотоках, дренирующих щелочные породы, геохимическую специализацию Кугдинского массива можно классифицировать как медно-никелевую.

Relevance. The extensive development of the Arctic territories and global climate change issues have attracted Geosciences researchers' attention to exploring the environmental characteristics of the Russian Arctic and subarctic territories over the past few decades. The outcrops of intrusive massifs in the northern part of Eastern Siberia are of interest due to the prospects for mineral deposits. At the same time, the terrestrial water systems of this region remain poorly studied. Inaccessible location and a virtual absence of infrastructure is the main account. Research of the water chemistry of intrusive massifs is challenging for explaining their formation mechanisms in the Arctic territories and improving hydrogeochemical exploration methods. The aim and object. The research object is the small watercourses draining the Kugda ultramafic alkaline intrusive massif and its carbonate margin located in the western part of the Anabar Plateau. The study aims to investigate the water chemistry and carry out a comparative analysis with the large rivers of the region as well as reveal the consistencies of the chemical composition formation. Methods. During the fieldwork in July-August 2020, three samples from small watercourses draining ultramafic alkaline massif and its carbonate margin were taken. The carbonate system components were determined by potentiometric titration. The anionic composition was determined by ion chromatography. Dissolved organic carbon was measured by the high-temperature catalytic oxidation method. Elemental analysis of water was carried out by ICP-AES and ICP-MS methods. Samples for elemental analysis were filtered through a polyethersulfone membrane of 0,45 mu m mesh into analytical pure 15 mL tubes with 0,45 mL of high purity HNO3 for conservation. Results and conclusions. The cationic content of the studied waters of the ultramafic alkaline massif and its margin reflects the rock composition adequately. At the same time, their anionic composition is controlled by a complex set of factors, both geochemical (rock composition and interaction with organic matter) and hydrological (recharging features). The small watercourse chemical composition draining the Kugda massif and its margin compared to the medium and large rivers of the region revealed the domination of magnesium in the cationic composition and increase in the proportion of potassium in contrast with sodium. The anionic composition of the small watercourses is relatively homogeneous; bicarbonate is sharply dominant, in contrast to large rivers, where the proportion of sulfate and chloride ions increases. The concentrations of trace elements in the surface waters draining the massif and its margin show that the composition of the studied waters can be used as an indicator of ore mineralization. The studied waters are enriched with such ore elements as Ni, Zn, Rb. According to the water migration coefficient values, Ni, Cu, Zn, Rb, Ag, Pb are readily removed from the rocks. Abundancies of trace elements in small watercourses draining alkaline rocks make the geochemical signature which could be classified as copper-nickel mineralization of the Kugda massif.

Abandoned mines are sources of potentially toxic chemical elements, although the development of these objects was completed. The Lupikko I mine area (Karelia Republic, Russia) is an excellent example of such technogenic objects. It is one of the largest mines in the Pitkäranta area, which was abandoned more than one hundred years ago. The dump rocks here are characterized by significant mineral diversity. Disseminated ore mineralization of the study area contains heavy metals, which enter the natural waters due to the oxidative dissolution of sulfides. Dump rocks and water from the Lupikko I mine area were collected to research the behavior of toxic elements. The samples were analyzed using ICP-MS, ICP-AES, potentiometric titration, ionic chromatography, X-ray microanalysis, X-ray fluorescence, and SEM to obtain information about the geochemical environment. According to new data, the content of Fe, Zn, Cu, Pb, Cd, and Ni in the natural waters of the mine significantly exceeds the geochemical background. For a more detailed study of the behavior of heavy metals, equilibrium-kinetic modeling, which considers the dissolution rate of ore minerals and the accumulation of toxic elements over time, was applied. A comparison of modeling data and field observations agreed. It was also found that for accurate modeling of Fe behavior, it is necessary to consider the organic matter content. Despite some model limitations, such retrospective assessments allow us to approve the applicability of this method for forecasting estimates.

The relevance. The study of the chemical element distribution in the water-rock system in areas of active development of mineral deposits is relevant because of the potential impact of these processes on environmental conditions. It changes the geochemical conditions of the natural environment. It is particularly important for the area under study, which is a part of the catchment of the largest natural fresh water reservoir in Europe - Lake Ladoga. The research aimed to study the aqueous removal of chemical elements from granitoid rocks opened-up by the quarry and the behavior of these elements in natural waters and bottom sediments of the region. The study objects are the natural waters and bottom sediments of the rubble stone quarry area (Pitkaranta ore district, Karelia). The authors traced the changes in the chemical composition of natural waters and associated bottom sediments as the water moves from its discharge from the quarry to inflow into the river network. Methods. The analysis of the chemical composition of natural waters and bottom sediments was carried out by standard methods: potentiometry, titrimetry, ICP-AES, ICP-MS. The study of the mineral composition of the quarry rocks was carried out using LA-ICP-MS. The chemical composition of the rocks was studied by XRF, ICP-MS, and ICP-AES. Thermodynamic modeling of metal speciation in natural waters and secondary mineral precipitation was conducted by the HydroGeo software package. The model was verified based on the analysis of the chemical composition of bottom sediments. Results. In the studied water bodies, an excess of the maximum permissible concentration of Fe, Mn, Cu, Zn, Mo, V at some points was found. The value of total dissolved solids and the content of the main components and Sr, U, V, Mo, Zn, Cd decrease with the increase of distance from the rubble stone quarry. The concentration of Fe increases due to the growth in the content of organic matter in the water. In bottom sediments, the maximum concentrations of many elements (Fe, Mn, Co, Cu, Zn, Cs, Ce, La, Y) is detected at the point of water discharge from the quarry. The maximum U content is observed slightly downstream from the mentioned point. It is consistent with the data on the composition of bottom sediments and modeling data, which indicate the possibility of uraninite precipitation from an aqueous solution in the point of water discharge from the quarry and the stream source originating in the discharge point. The role of organic matter is essential for Fe accumulation in water due to the formation of a stable hydroxo-fulvate complex of Fe and rare earth elements due to the formation of complexes with humic acids. Analysis of the metal distribution and speciation and secondary mineral precipitation allowed us to conclude that the exploitation of the rubble stone quarry affects the redistribution of chemical elements in the study area significantly.