Otechestvennoe Tin Deposit (Magadan Region, North-East Russia): Genesis and Bismuth Mineralization

Gold mining generates major environmental impacts like landscape degradation, accumulation of waste rock dumps, and water contamination by suspended solids. Russia ranks third in the world in gold production, but the impact of gold mining has not been previously estimated for its vast northeastern part. This study provides a detailed overview of land-cover changes associated with gold mining in the Magadan region (northeast Russia) in the 21st century, where alluvial gold production has increased by a third in the last 20 years. A long-term series of Landsat and Sentinel-2 images obtained in July and August are used to compile two datasets of mining-impacted areas with totally removed vegetation for 2000–2002 and 2022. We calculated the NDVI difference and then discriminated mining-related vegetation losses from other bare areas, using additional data like the classification of landforms based on the digital surface model and the data on mining allotments. The total area of gold-mining sites was estimated as 41,206 ha in 2000–2002 and 72,602 ha in 2022, with an increase of 26,031 ha over the past 4–6 years. Moreover, this is a lower-boundary estimate, without taking into account man-made reservoirs and historical mines recovered by vegetation. The spatial distribution of mining sites has not changed significantly over the past two decades and has a maximum in the western part of the region. We found that the floodplains of the Berelekh and Debin Rivers (large tributaries of the Kolyma River) are most heavily impacted by gold mining with a removed vegetation canopy occupying 16.0% and 11.2% of their area. Along with the land degradation assessment, we found that 19,900 ha of historical gold-mining sites in the Berelekh River basin are recovered by vegetation, which is comparable in size to the areas impacted by mining over the past 20 years.

: A seismicity catalog and associated list of phases for many events has been compiled for northeast Russia using published and unpublished data from the regional networks operating in eastern Russia (primarily Magadan, Yakutsk and Amur), and international data files. The catalog contains about 39,000 events and 150,000 arrival times. The resultant catalog is contaminated by industrial explosions, particularly in the Amur and central Magadan districts. A preliminary crustal velocity model was developed by obtaining best fit travel curves in conjunction with locating approximately 1300 events in eastern Russia. The velocities obtained are generally in agreement with inferred tectonic regimes. These travel time curves were then used to relocate 134 larger regional events; 26 are classified as GT10. From these relocated events consistent patterns of residuals, essentially representing Source Specific Station Corrections (SSSCs), show upper mantle velocities are elevated under the Siberian platform and slower below the Sea of Okhotsk. Seismic station parameters for the region were also compiled. To further improve calibration capabilities in northeast Russia, a small network of digital seismic stations was deployed in the Magadan region, recording both earthquakes and ground truth mine blasts. Preliminary analysis of Lg amplitude ratios indicate that the ratio Lg(4-8Hz)Lg(0.75-1.5Hz) using peak amplitudes is not sufficient to discriminate mining explosions from earthquakes at local and near regional distances (<500km) in northeast Russia.

The huge Anmangynda aufeis is located in the valley of the river of the same name in the Magadan region in North-East of Russia. This is the only in the world aufeis site with a 30-years period of ground-based observations (1962–1991). The materials of these observations were supplemented with data obtained from the analysis of Landsat and Sentinel satellite images for the period 2000–2021, as well as the results of field investigations carried out in 2020–2021. The long-term variability of the maximum area, volume and average thickness of ice, the dynamics of formation and destruction of the aufeis ice in the cold and warm periods of the year were analyzed. It was found that the maximum values of the area and volume of ice on the dates before the start of ablation decreased by 25 and 33%, respectively. In 2000–2021, the average values of the aufeis characteristics are estimated as 4.7 km2 and 7.1 million m3, while in 1962–1991 – 5.5 km2 and 8.5 million m3. The analysis of the intra-annual dynamics revealed that the Anmangynda aufeis being earlier the perennial formation has transformed to the seasonal one. Further researches of the Anmangynda aufeis will make possible to assess the influence of various factors, including climatic ones, on the processes of an aufeis formation and to forecast their changes in the future for the cryolitic zone of the North-East of our country.

The Late Cretaceous Pterophyllum (Bennettitales) in the North-East of Russia

BACKGROUND: A substantial body of research has focused on adaptation of the new residents of the European and Asian Far North. However, these publications fail to address the changes occurring in successive generations of native Caucasians who migrated to the regions with harsh climatic conditions.&#x0D; AIM: To study functional adaptations exhibited by individuals born in the Magadan Region to various generations of Caucasians permanently living in the area.&#x0D; METHODS: A total of 1632 male volunteers, all students aged 181.1 years, and of Caucasian ethnicity, participated in this study. These individuals were either migrants or residents of Russia's North-East, born within the first to third generations. We investigated anthropometric characteristics, cardiohemodynamic parameters, and gas exchange to understand the adaptive readjustments that take place within the body's functional systems.&#x0D; RESULTS: Migrants and first-generation residents in the Magadan region experience constant stress and inadequate functioning of their cardiohemodynamic and energy exchange systems under extreme conditions. However, the third-generation subjects exhibited optimal performance of the cardiovascular system. Remarkably, the third-generation residents demonstrate an increased systolic volume at lower arterial pressure and lower total peripheral resistance. Furthermore, they had elevated proportion of the high frequency component and total power of the heart rhythm spectrum. This represents a new level of changed influence on the heart rhythm, as seen in the altered balance of its statistical and spectral wave characteristics. Moreover, the adaptability of the cardiovascular system to the harsh conditions of the North is reflected not only in the physiological indicators of the body but also in the integral structure of their correlations. This includes the magnitude and sign of the correlation coefficients and their significance.&#x0D; CONCLUSIONS: Our main findings suggest that adaptive changes in cardiohemodynamic and gas exchange exhibited by the migrants and several generations of residents of the Far North-East of Russia are directed to minimization of the total energy expenditure in functional systems. Additionally, the parasympathetic contribution increases fostering a novel interaction between the components of autonomic nervous regulation reflected by both qualitative and quantitative alterations in the structure and patterns of correlation clusters. These findings contribute to our understanding of the physiological mechanisms behind the morphofunctional readjustments of Caucasian men in the process of adaptation to the harsh climatic conditions of the Russian North-East.

Since 2004, the Russian Federation has been taking more and more active steps to reduce tobacco consumption, but the epidemiological situation still indicates a low effectiveness of tobacco control measures in several regions of the country. Magadan Region is one of the worst in Russia on the epidemiology of tobacco; its example can show gaps in the state’s tobacco control policy and help work out measures to improve the situation.Aim. Analysis of the tobacco epidemiology in Magadan Region.Methods. A wide survey of the population of the region aged over 15 was performed. A total of 341 people were involved in the survey. The collected data included general information about the respondent, information on tobacco use, tobacco cessation, secondhand smoke, the economy, the media, knowledge, attitudes and perceptions related to tobacco use. The type of the sample was quota based on gender, age and geographical distribution of the population.Results. The study showed that 42% of the population of the region over 15 years old used tobacco regularly. About 90% of the respondents became addicted between 13 and 22 years. The modal consumption values are 10 or 20 cigarettes per day. The average spending on tobacco is about 42 thousand Rubles per year per smoker. Up to a 1/3 of smokers have tried but failed to give up their addiction over the previous year. At the same time, an extremely poor knowledge of the methods of anti-smoking therapy was observed. About 80% of the tobacco users would like to quit smoking in the future.Conclusion. The relatively small costs of tobacco expenses in regions with a high level of income hinder the most effective method of tobacco control – raising taxes on tobacco products.

Copper mineralization in the Magadan region (North-East of Russia) has been established in quartz-chloritoid and chlorite shales of the middle and upper Riphean of the Prikolymsky terrane. Compared to the upper crust, copper shales of the Oroek deposit are noticeably enriched in a narrow range of trace elements: Cu, Ag, Au, Rh, and Se, with enrichment factors ranging from 10-fold (Se, Rh) to 100-fold (Ag, Au) and even 1000-fold (Cu) suggesting, apparently, their synchronous involvement in ore formation. In addition, the studied samples are slightly enriched in Cd, Li, Co, Zn, V, U, Sc, Y, and REE. Copper shales show relatively flat rare earth element (REE) patterns similar to the chondrite-normalized pattern having no distinct positive or negative Eu anomalies and dominated by light lanthanides. The Ce/Ce* and Eu/Eu* values indicate that ore formation proceeded under oxidizing conditions. The obtained geochemical data show that the Riphean host rocks could serve as a source of trace elements and REE ore-forming fluids. In the ores, covellin and chalcocite are the main copper minerals; less common are roxbyite, idaite, nukundamite, spioncopite, chalcopyrite, silver-bearing (Ag about 1 wt. %) bornite and yarrovite, as well as native gold. Fluid inclusions in quartz suggest that copper mineralization was formed at temperatures of 212–190 °C and a pressure of 1 kbar, from hydrothermal solutions of medium salinity (from 13.8 to 12.4 wt. % eq. NaCl) and high density (0.95–0.98 g/cm3) saturated with chlorides of Ca, Mg, and K. The copper shales of the Prikolymsky terrane differ from sedimentary copper and copper shales of the African Belt by low Co and Ni contents and from the Kupfershifer by low concentrations of Pb and Zn. The obtained results can be used for prognosticating new deposits.

Significance. According to WHO, unbalanced diet is one of the leading causes of chronic diseases. Adolescence should be considered a person’s life most important period in terms of developing eating habits that define the body macro- and micronutrient intake. The purpose of the study was to assess diet type and balance and specify region-related macro- and micronutrient diet profiles among young Caucasian and Aborigine males in the North-East of Russia. Material and method. ASPON-nutrition software program was used to analyze the availability of proteins, fats, carbohydrates, fiber, vitamins, as well as macro- and microelements in diets of young males residing in the Magadan Region and Chukotka Autonomous District (mean age equals to 17-21 years, n = 278). Results. The study has identified a clear imbalance in the diet characterized by a low intake of the protein-lipid component, a shortage of polyunsaturated fatty acids, and a complete lack of fiber intake against the background of the increased share of mono- and disaccharides as well a deficiency of macro-, microelements and vitamins in the diet. The deviations have proved to be typical of people residing in the city of Magadan, primarily of the young indigenous population who experience a 100 percent nutritional deficit for a number of components.

Aim: To study physiological conditions of the human body at different stages of adaptation to the climatic conditions of the High North. Methods: A longitudinal study included 17-21-year-old young men (n = 1 310) in the Magadan region (North-East of Russia) that were followed up for 10 years. Parameters of the cardio-respiratory system, the structure of the microvasculature, as well as the data of the biochemical profile and basic metabolism of the subjects were measured and analyzed. Results: Our main findings suggest that longer duration of residence in the High North is associated with decreased functional stress in cardiovascular and respiratory systems. The proportion of individuals with abnormal basal metabolic parameters and hyperglycemia was inversely associated with duration of stay in the High North. At the same time, the percentage of alterations in microcirculation indices increases from the 0 to the third generation of residents of the High North. Conclusion: The results of the study are in general in line with the results of earlier studies on conditions of the main physiological systems at different stages of adaptation. They provide additional support to the hypothesis of the formation of a new population of inhabitants in the Russian High North that were newcomers but gradually adapted to the conditions of the North.

In the second half of the 20th century the process of global climate change has begun on the Earth, the atmosphere and the ocean have warmed up, snow and ice reserves decreased, the sea level rose, concentrations of greenhouse gases increased. An ongoing warming response has been recorded also in most of Northeast Asia. Climate and its change affect the life of the biota. The aim of this study is to reveal ongoing changes in the thermal regime in and around Magadansky Strict Nature Reserve, which is located in North-East Russia, in the Magadan Region. The nature reserve has four separate areas with maritime, sharply continental and transitional climates. Weather stations Magadan, Talon, Seimchan provide data that characterize the climate in the nature reserve. The annual duration of periods with mean daily temperatures above 5°C (growing season) were calculated for years 1953-2013 using long-term air temperature data series from the above weather stations. 30-year moving averages (tentative normals) were calculated from these series. Tentative winter season (with mean daily air temperatures steadily below 0°C) normals were determined similarly. The calculations and plotting were performed using Microsoft Excel spreadsheet software. Long-term series of mean annual air temperatures demonstrated statistically significant upward trends. Annual air temperatures averaged over 1984-2013 were 1.1-1.2 °C higher compared to the preceding 30-year period. This resulted in a shift of the onset and end of the growing season and winter season. Their tentative normal durations trended in the opposite directions. The average duration of the growing season increased by 4-6 days, whereas the average duration of the winter season decreased by 4-8 days. Tentative normal durations of the growing season and winter season correlate well with mean annual air temperature. Formulas were obtained for calculating normal durations of these seasons under different scenarios of mean annual air temperature rise in the 21st century.

Classification of subalpine meadows of the Chersky and Kolymsky mountain ranges (Magadan region, Chukotka) has been performed according to the Braun-Blanquet approach. The plant communities belong to 2 associations and 4 variants. The new alliance — Aconito delphinifolii–Caricion podocarpae and two new associations — Tilingio ajanensis–Festucetum altaicae and Spiraeo beauverdianae–Calamagrostietum purpureae are described. Distribution of the alliance Aconito delphinifolii–Caricion podocarpae in the Russian North-East is discussed. Chorological analysis of coenoflora of the alliance has been done.

An attempt was made to use GIS technologies for the development of methods of prognostic evaluation of the metal potential of a local territory based on mathematical statistics. The Degdekan-Arga-Yuryakh mineral district (Magadan region) was chosen as the research subject, where a spatial database of the geology and mineral resources was established. The application of methods of the spatial-statistical analysis of diverse cartographical-geological information provided the quantitative assessment of the spatial location of geological objects and gold mineralization in the region. Consequently, we were able to perform the spatial analysis of the location conditions of the gold deposits and recognize their relation to the geological characteristics. Based on the revealed geological features favorable for the location of mineralization, we distinguished two areas promising for commercial mineralization prospecting. Our work demonstrated the sufficient efficiency of the applied methods in large-scale metallogenic investigations at the ore cluster level.

Summary Modeling has been carried out on the basis of the structural mapped of the folded structures of the Teutedzhak gold ore field in the back-arc zone of the Okhotsk-Chukotka volcanogenic belt. According to the structural position, three generations of intrusions have been divided: pre-ore sills, possibly ore-controlling granodiorites and diorites and post-ore granitoid dikes. Based on the analysis of fracturing and orientation of quartz veinlets, it was concluded that there is a series of ore-bearing stockworks of northwestern strike in the ore field.

BACKGROUND: Adaptation to climatic conditions influences the main characteristics of subjective physical development and morphofunctional state. These characteristics tend to differ in different geographical regions of northeast Russia.&#x0D; AIMS: A comparative analysis of basic somatometric indicators was conducted to identify differences between representatives of Magadan Region and Chukotka Autonomous District.&#x0D; MATERIAL AND METHODS: One hundred and ninety-eight young men aged 1721 years old (Koryaks and Evens) from Magadan Region (the City of Magadan) and 87 young men (Chukchi) aged 1721 years old from Chukotka Autonomous District (the City of Anadyr) participated in this study. Chest circumference was measured, and body mass index and body area were calculated by using the length and weight of the body. The strength of the physique was estimated by applying the Pinier index, and the total body fat content in the two groups was determined.&#x0D; RESULTS: Somatometric indicators exhibited by modern young male aborigines inhabiting different regions of the Far East demonstrated no significant differences between groups. However, relative to that to that of their peers in previous years, the subjective overall body size of the analyzed samples from the two regions had increased (body length: by 7.7 cm in the Chukotka Autonomous Okrug and 6.5 cm in the Magadan Region; body weight: by 3.7 kg in the Chukotka Autonomous Okrug and by 4.4 kg in the Magadan Region).&#x0D; CONCLUSION: Aborigines from Magadan Region and Chukotka Autonomous District developed morphotypes with accelerated variables. The changes observed were not dependent on the region of residence or ethnicity.

The aim of the study is to evaluate the mineral profile of black currant fruit (Ribes nigrum l.) growing in the North-East of Russia, on the territory of the Magadan region. Material and methods. Berry samples were collected within the forest zone of Magadan from wild plants. Atomic emission spectrometry and inductively coupled plasma mass spectrometry were used to determine the content of 25 minerals and trace elements in the objects under study. Results and discussion. The content of minerals - calcium (64.2 mg%), magnesium (21.6 mg%), sodium (0.3 mg%), phosphorus (51.8 mg%) and trace elements - iodine (1.0 μg%), zinc (0.29 mg%) in black currant fruits (Ribes nigrum l.), growing in the forest zone of Magadan, corresponded to the database of chemical composition of Germany, Spain, Norway, Russia, USA, France, Sweden, Estonia. The content of potassium (180.3 mg%), copper (0.05 mg%), iron (0.4 mg%), manganese (0.1 mg%) was below the reference ranges. A portion (100 g) of black currant berries satisfies the daily requirement of an adult for selenium by 11%, potassium by 7%, phosphorus by 6.5%, calcium, magnesium, copper, manganese - by 5%, iron by 3-4%, zinc by 2%. Conclusion. The obtained data on the content of minerals and trace elements in the berries of wild black currant growing in the North-East of Russia, can be an addition to and clarification of the information available in the literature and database on the chemical composition of foods.