Magadan Region Research Articles

Heat-insulating foam-silicate materials

Purpose: The aim of this work is to study the density, thermal conductivity and strength of insulating materials and fine-grained concrete based on cement binder with the use of foamed silicates. Vermiculite from Tatarsky deposit (Krasnoyarsk region), perlite from Khasynsky (Magadan region) and Mukhor-Talinsky (Republic of Buryatia) deposits, and tripoli from Potaninsky deposit (Chelyabinsk region) are used to obtain porous fillers.Research findings: It was found that the strength of materials based on cement binder and foamed silicates is determined by the strength of hydrated cement, aggregate, and contact zone of hydrated cement and filler. The coefficient of thermal conductivity of insulating materials based on foamed granules of natural dispersed raw materials (vermiculite, perlite, tripoli) with cement (23.5 vol. %) ranges from 0.112 to 0.181 W/(m·deg), which is 1.5–1.6 times higher than thermal conductivity of the granular layer.Compressive strength of the obtained materials ranges between 2.0 and 4.0 MPa. Compressive strength of lightweight concrete with the silica sand content of 32 vol.% and plasticizer, increases up to 8.5 MPa in compositions with vermiculite and up to 9.4 MPa in compositions with perlite from Mukhor-Talinskoe deposit.Depending on the quartz sand content, the density of concrete with foamed vermiculite and foamed perlite varies from 1100 to 1400 kg/m3 and from 1300 to 1600 kg/m3, respectively. Thermal conductivity of concretes with minimum density is 0.193 W/(m·deg) in the composition with vermiculite and 0.286 W/(m·deg) in the composition with perlite. At the maximum density of fine-grained concrete, the thermal conductivity increases to 0.277 and 0.411 W/(m·deg), respectively.

Genetic history of the Koryaks and Evens of the Magadan region based on Y chromosome polymorphism data.

In order to clarify the history of gene pool formation of the indigenous populations of the Northern Priokhotye (the northern coast of the Sea of Okhotsk), Y-chromosome polymorphisms were studied in the Koryaks and Evens living in the Magadan region. The results of the study showed that the male gene pool of the Koryaks is represented by haplogroups C-B90-B91, N-B202, and Q-B143, which are also widespread in other peoples of Northeastern Siberia, mainly of Paleo-Asiatic origin. High frequency of haplogroup C-B80, typical of other Tungus-Manchurian peoples, is characteristic of the Evens of the Magadan region. The shared components of the gene pools of the Koryaks and Evens are haplogroups R-M17 and I-P37.2 inherited as a result of admixture with Eastern Europeans (mainly Russians). The high frequency of such Y chromosome haplogroups in the Koryaks (16.7 %) and Evens (37.8 %) is indicative of close interethnic contacts during the last centuries, and most probably especially during the Soviet period. The genetic contribution of the European males' Y chromosome significantly prevails over that of maternally inherited mitochondrial DNA. The study of the Y chromosome haplogroup diversity has shown that only relatively young phylogenetic branches have been preserved in the Koryak gene pool. The age of the oldest component of the Koryak gene pool (haplogroup C-B90-B91) is estimated to be about 3.8 thousand years, the age of the younger haplogroups Q-B143 and N-B202 is about 2.8 and 2.4 thousand years, respectively. Haplogroups C-B90-B91 and N-B202 are Siberian in origin, and haplogroup Q-B143 was apparently inherited by the ancestors of the Koryaks and other Paleo-Asiatic peoples from the Paleo-Eskimos as a result of their migrations to Northeast Asia from the Americas. The analysis of microsatellite loci for haplogroup Q-B143 in the Eskimos of Greenland, Canada and Alaska as well as in the indigenous peoples of Northeastern Siberia showed a decrease in genetic diversity from east to west, pointing to the direction of distribution of the Paleo-Eskimo genetic component in the circumpolar region of America and Asia. At the same time, the Evens appeared in the Northern Priokhotye much later (in the XVII century) as a result of the expansion of the Tungusic tribes, which is confirmed by the results of the analysis of haplogroup C-B80 polymorphisms.

1166A>C polymorphism of the <i>AGTR1</i> gene as a marker metabolic disorders in the North residents

BACKGROUND: dyslipidemia is currently considered to be one of cardiovascular risk factors. Angiotensin II receptor type I (AGTR1) genetic polymorphisms are known as candidate genes for hypertension, diabetes, as well as for diabetes and obesity complications. Until now, there are not much data on how 1166A>C (rs5186) polymorphism of the AGTR1 gene correlates with Northerners’ carbohydrate and lipid metabolism disorders. In addition, the data are contradictory. Following on from this, we see it is relevant to study the subject.AIM: this research assessed variants of 1166A>C (rs5186) polymorphism of the AGTR1 gene as a predictor of dyslipidemia, carbohydrate metabolism disorders, overweight, and hypertension.MATERIALS AND METHODS: the North residents from Magadan Region, Caucasian by ethnicity, aged from 24 to 56 (average age 43.7± 1.4 yrs) participated in the survey. By real-time polymerase chain reaction we determined the single nucleotide polymorphism of the AGTR1 (rs5186) gene. We also analyzed physical development and cardiovascular variables as well as the concentrations of glucose, insulin, glycosylated hemoglobin, C-reactive protein, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. The insulin resistance index and the atherogenicity coefficient were calculated using standard methods.RESULTS: the examined subjects were one hundred and one volunteers. According to the results of genetic analysis, 55 people were assigned to the group of homozygotes for the wild type (AA) and 46 people were assigned to the group of the AGTR1*C allele variant carriers (heterozygotes and homozygotes AC+CC). Our findings contributed to the evidence on more unfavorable lipid pictures showed by the AGTR1*C allele variant carriers: significantly high values of total cholesterol (5,77±0,11, р=0.045), low-density lipoproteins (3,87±0,09, р=0.009), triglycerides (1,43±0,06, р=0.035), and atherogenicity coefficient (3,61±0,10, р=0.001), along with significantly low values of high-density lipoproteins (1,30±0,03, р=0,008). The above indicators were observed as opposed to significantly high fasting glycemia (5,74±0,14, р=0.006) and glycosylated hemoglobin (5,74±0,09, р=0.001) exhibited by the AA homozygotes subjects whose indices could be defined as the state of prediabetes. No intergroup differences were found in anthropometric or cardiovascular variables.CONCLUSION: thus, we could see impairments in the lipid pictures of the AGTR1*С polymorphic variant carriers along with the optimization of carbohydrate metabolism and no effect on the blood pressure or anthropometric characteristics.

Flora of the Magadan Region from the “Flora…” by A.P. Khokrjakov to modern databases

The A.P. Khokhryakov’s contribution in development of knowledge of the “white spot” on a floristic map of Russia – the Magadan region, foundation of a scientifi c herbarium, which currently holds more than 110 thousand specimens of vascular plants, numerous research fields of the laboratory of botany organized by him at the Institute of Biological Problems of the North (Magadan) are presented and discussed. The Herbarium (MAG) appeared in the global network of digital herbaria in 2020, now developing on its own platform/portal https://herbarium.ibpn.ru/.

A.P. Khokhrjakov and the botanical geography of the Okhotsk-Kolyma Region

The Magadan period in life and scientific career of the remarkable botanist A.P. Khokhrjakov is described. He devoted a significant part of his creative life to this mountainous harsh, but amazing edge of our country. Botanical geography became one of the focuses among a wide range of his scientifi c interests during that period of intensive study of flora and vegetation of the vast mountainous territories of the Magadan region and neighboring territories. A deep multidimensional analysis of flora with the allocation of its geographical and genetic elements together with a thorough attention to the endemic and relict species, became an outcome of these studies. That basis allowed him to approach an understanding of the formation and development of the flora of various regions, making his original contribution to the development of botanical, geographical and floral zoning of Northeast Asia. Numerous publications by A.P. Khokhrjakov remain in demand and serve as necessary sources of information on this complex and distinctive mountain flora.

Genetic and ecological differentiation of Caragana jubata (Pall.) Poir.

Caragana jubata (Pall.) Poir. is a cold-tolerant mountain shrub and important medicinal species of Fabaceae family with a disjunctive pan-Asian range. Sequences of the atpH-atpI and trnL-trnF intergenic spacers of chloroplast DNA and of the internal transcribed spacer region, ITS-1, of the nuclear ribosomal DNA were used to investigate the intraspecific evolution and phylogeography of this species. Eleven cpDNA haplotypes were identified. The population subdivision is very high (GST = 0.743, NST = 0.943), suggesting a distinct phylogeographic structure (NST > GST, P < 0.001). Phylogenetic analyses of the eleven haplotypes were clustered into four clades, consistent with their respective distributions in four separate regions: Tibet, Tien Shan, Buryatia and Magadan Region. This pronounced phylogeographic gap is also confirmed by nrITS data, however, there is some mixture of genotypes in the Magadan and Buryat populations. Genetic evidence suggests that the center of origin of C. jubata was Tibet and adjacent mountain systems, from where the species spread westwards along continuous mountain chains towards the Tien Shan and northeastwards to the coast of the Sea of Okhotsk and further northwards to Arctic. Divergence of Tien Shan populations of C. jubata may have been caused by climate change in the Pleistocene associated with increased aridity and expansion of deserts, while subsequent climate-induced cycles of range contraction/expansion increased geographic isolation and fragmentation of more northern populations. Marginal northern populations now occupy sites with the most favourable environmental conditions. Special attention is paid to the Okhotsk populations of this species preserved in Magadan Region.

Genomic constitution and origin of the endemic intergeneric hybrid × Elyleymus magadanensis (Poaceae) from the Magadan Region (Russia)

The North Okhotsk endemic × Elyleymus magadanensis Khokhr. is presumably an intergeneric hybrid of Elymus boreoochotensis and Leymus mollis. A comprehensive study of a unique population of the species from a classic habitat in the vicinity of Magadan was carried out. Analysis of ISSR-fragments DNA showed the genetic heterogeneity of the sample of natural individuals. The chromosome number was established to be 2n = 4x = 28, this is consistent with the assumption that the hybrid genotypes of the species have an allotetraploid constitution, including the St and H subgenomes from the genus Elymus and the Ns and Xm subgenomes from Leymus mollis. Sequences of genes GBSS1 and β-amylase were analyzed in the putative parental genotypes of E. confusus, E. sibiricus and two accessions of × Elyleymus magadanensis. Cluster analysis of sequences made it possible to confirm the origin of × Elyleymus magadanensis as a result of hybridization of E. confusus and L. mollis. It was concluded that the hybrid taxon is a sterile amphihaploid with the most probable genomic formula Ns1Ns2StH.

Влияние активированного угля на эффективность сорбционного выщелачивания золотосодержащих руд (на примере обогатительной фабрики ГОКа «Кубака»)

Activated granular coal is widely used in processing plants, both in Russia and abroad. There are two problems at Kubaka mining and processing plant (MPP) during hydrometallurgical processing of gold-containing raw materials: loss of coal during sorption due to partial abrasion, decrease in sorption properties and, as a result, deterioration of coal quality as a result of clogging of pores with dissolved compounds in the pulp. This in turn leads to a decrease in the efficiency of sorption leaching of gold-bearing ores and an increase in the cost of gold. The aim of the study is to improve the quality of activated carbon of the GOLGCARB 207C 6X12 brand based on the use of reduction processes in order to increase the sorption capacity. Research objectives are as follows: development of a research methodology; determination of parameters of changes in the kinetic properties of activated carbon; step-by-step assessment of changes in the properties of activated carbon in the technological process; identification of the effect of coal treatment with alternative reagents (NaOH, hydrochloric acid, sulfuric acid, lime) on improving the quality of activated carbon. The object of the study is activated carbons of the GOLGCARB 207C 6X12 brand used at the Kubaka MPP (Magadan region). Research methodology and methods are as follows: a comprehensive methodology for the study of activated carbon, laboratory studies and pilot tests. The effect of activated carbon on the efficiency of sorption leaching of gold-bearing ores in laboratory conditions with the approbation of a new technological solution in semi-industrial tests has been studied. The effect of acid treatment and reactivation of coal on its sorption properties has been experimentally proven. Optimal conditions for cleaning the pores of coal from impurities of organic, carbonate and sulfur-containing compounds and an increase in sorption activity were achieved by acid treatment (replacement of hydrochloric acid with sulfuric acid) and pH control.

Развитие строительства и промышленности строительных материалов в Магаданской области в 1953–1964 гг.

The article is devoted to a comprehensive analysis of the development of the construction industry and construction materials industry in the Magadan Region in 1953–1964. The key areas and results of construction activities, the dynamics of capital investments in construction in various sectors of the economy, the establishment and development of enterprises for the production of wall materials, precast concrete and other construction industry in the region are examined. Particular attention is paid to the analysis of the problems of logistical support for construction, the cost of building materials, and the shortage of certain types of products. The pace and volume of housing and social and cultural construction are considered. Based on a wide range of archival sources, it is concluded that the development of construction and local production of building materials was of great importance for the formation of the Magadan Region as a northern region of the country during the period under review.

The effect of ω-3 polyunsaturated fatty acids on carbohydrate metabolism in northern men

Omega-3 polyunsaturated fatty acids (PUFA) are known for being one of the most important classes of bioactive lipids; of them, the long-chain ones, namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, have many positive effects on the human body. The aim of this study was to assess the carbohydrate metabolism in northern men living in the Magadan Region before and after the administration of a dietary supplement with PUFA. Material and methods. The study included 45 men (mean age 40.0±0.8 years), of whom 2 groups comparable in age and analyzed parameters were formed by random sampling. The participants of the main group (n=30) consumed PUFA (2 capsules containing 1200 mg, including 660 mg EPA and 440 mg DHA), and the control group (n=15) had no impact on the diet. Fasting venous blood was collected using a vacuum system to determine glycated hemoglobin (HbA1c) using the turbidimetric immunoinhibition, glucose by the hexokinase method, insulin by the immune chemiluminescence using paramagnetic particles at the beginning (late October, 2023) and the end (mid-December, 2023) of the study, and HOMA-IR index was calculated. The daily diet was assessed using the ASPON-nutrition program (St. Petersburg) based on the results of the food diary keeping for 3 days (weekdays). Results. In men of the main group, positive changes in the carbohydrate profile were noted, associated with the intake of ω-3 PUFAs, manifested in HbA1c decrease (from 5.5±0.1 to 5.2±0.1%, p<0.05) while maintaining blood concentration of glucose and insulin and HOMA-IR at the same level. Unlike the main group, the control group experienced disadaptation in their carbohydrate metabolism as they exhibited the signs of hyperinsulinemia (increased basal fasting insulin level from 8.8±1.2 to 11.4±1.1 mIU/l, p<0.05) and insulin resistance (the increase in the HOMA-IR from 2.0±0.2 to 2.6±0.3, p<0.05), which was apparently due to the autumn-winter period of the study. Conclusion. Resulting from the data obtained, this study showed the presence of a leveling function and even an optimizing role of additional ω-3 PUFAs intake with respect to seasonal changes in the biochemical parameters of the northern residents during the crucial period of the year with its temperature curve transition through 0 °C.

ОТРАЖЕНИЕ В ЭКОЛОГИЧЕСКИХ ПРОГРАММАХ СУБЪЕКТОВ ДАЛЬНЕВОСТОЧНОГО ФЕДЕРАЛЬНОГО ОКРУГА СПЕЦИФИКИ РЕГИОНАЛЬНОГО РАЗВИТИЯ

The main ideas of the regional environmental policy are presented in the programmes «Environment Protection». These programs accumulate the tasks, which solution ensures the achievement of environmental targets in the outlines of the socio-economic development of a particular territory. The hypothesis of the current research states that the raw material specialization of the economic development of the Far Eastern Federal district has an impact on the solution of the targets identified in the environmental programs and reduces their effectiveness. The purpose of this paper, which is part of the authors’ large-scale research aimed at improving the structure of environmental programmes, is to reveal the specifics of the formation and content of environmental protection programmes in regions specializing in the extractive sectors of the economy. The study is based on the information of the state programmes «Environmental Protection» of five Far Eastern subjects adopted for the period 2020–2025: Magadan region, Sakhalin region, Sakha Republic, Chukotka Autonomous District, Kamchatka Krai. These subjects are characterized by high potential of economic development and also predominance of resource industries in the territorial sectoral structure of the economy. The article analyses 205 indicators of ecological programmes of resource regions. It was found that only 17% of all indicators are aimed at improving the environmental situation, 13% ensure this process, 23% are not directly related to the environmental issues. It was concluded that the content of the programmes does not fully correspond to the priority areas of environmental policy, such as rational environmental management and reducing the negative impact on the environment, waste management, etc. The identified drawbacks of environmental programmes of resource-oriented regions should be taken into account in the formation of further environmental policy, while the new programmes should reflect the resource specialization of the regional economy in the form of special indicators.

Late Pleistocene and Holocene Sedimentation in the glacial Lake Sosednee, Magadan region

Lake Sosednee is located in the Yagodninsky district of the Magadan region. It was formed in the Late Pleistocene around 22,500 cal. years ago. The rock magnetic, geochemical, palynological, and mineralogical characteristics of the sediments of four cores, as well as moraine, and various grain size fractions of the hillslope sediments were studied. It has been established that the geochemical and rock magnetic properties of sediments from lake Sosednee reflect different sedimentation conditions, changing from the cold climate of the Late Pleistocene to the warm climate of the Holocene. In the lower part of the core, authigenic (hemogenic) formation of iron sulfides, including magnetic ones, was revealed. According to the rock magnetic and geochemical data, the Younger Dryas was identified, the end of which corresponds to the Pleistocene–Holocene boundary.

Soils of the island bars of the Ola lagoon (Okhotsk sea)

The aim of the study. The purpose of the work is investigating soil formation on the island bars of the Ola Lagoon, as soil formation there has a special character due to the severe climate, dynamism and small age of the landscapes, and the influence of marine colonial birds. Location and time of the study. Field studies were conducted in June-July 2022 in the coastal zone of the Ola Lagoon of Magadan Region; laboratory and desk studies were conducted in 2022 and 2023. Methods. Methods included route observations with soil profile descriptions, mesomorphological studies; soil physical and chemical analyses: pH, electrical conductivity (TDS), loss on ignition (LOI); satellite photos interpretation and soil mapping. Results. The bar soils were qualified as dry-peat lithozems, differing in the thickness of the dry peat horizon TJ and the abundance of skeletal material (pebble). The dry-peat horizon is gradually merging into parent rock - dense marine pebbles, which are sometimes found in the dry-peat horizon due to storm "surges" from the sea. The TJ horizon consists of mesophilic plant residues and morphons of dark fine-disperse matter and a large number of semi-decomposed and living roots penetrating into the pebble layer. In the WRB system, soils correspond to Histic Leptosols (if shallow), or to Mawic Fibric Histosols. Conclusion. Formation of the dry-peat lithozems with the TJ-(TJ/С)-C profile is determined by the dry marine climate and low plant diversity of the meadows dominated by reed grass and wild rye. The main factors, shaping soil properties, are the island bars dynamics, specific of pebbles a parent rock material, salt impulverization and marine birds colonies presence. The research expands the knowledge on poorly studied soils of the region, and may contribute to substantiating their position in the classification of soils of Russia; in addition, the data obtained are useful within the framework of sustainable development, as it serves as nesting ground for colonial seabirds.

Helminth fauna of saffron cod &lt;i&gt;Eleginus gracilis&lt;/i&gt; in the coastal waters of the Magadan Region (northern coast of the Okhotsk Sea)

Results of parasitological investigation of saffron cod Eleginus gracilis Tilesius, 1810 are presented. The fish samples were collected in 6 distanced marine areas at the coast of Magadan Region, generally corresponded with local stocks or herds of this species. In total, 29 helminth species are identified, including 8 cestodes, 11 trematodes, 5 nematodes, and 5 acanthocephalans. The highest species diversity of helminths is detected for the saffron cod from the Odyan Bay (24 species) and the lowest – for the saffron cod from the Amakhton Bay (16 species). Occurrence and intensity of infestation is the highest for trematodes Hemiurus levinseni, Podocotyle reflexa, and Brachyphallus crenatus, nematodes Ascarophis pacifica, and acanthocephalans Echinorhynchus gadi and Corynosoma strumosum. The number of detected worm species is close to the total number of these parasites recorded for saffron cod in the Far-Eastern Seas and adjacent Pacific – 33 species (excluding monogeneans). Cestodes Diplocotyle olrikii, trematodes Bucephaloides iskaensis, and acanthocephalans Bolbosoma caenoforme are registered for the first time for saffron cod in the Okhotsk Sea. There is found for the first time in the studied area that saffron cod is a definitive host for trematodes Steganoderma formosum and a paratenic host for acanthocephalans Andracantha mergi. Eight species dangerous from medical and (or) veterinary point are detected: Nybelinia surmenicola, Diphyllobothrium sp., Pyramicocephalus phocarum, Anisakis simplex, Pseudoterranova decipiens, Bolbosoma caenoforme, Corynosoma semerme, and C. strumosum. The data on helminth infestation are not useful for differentiation of the saffron cod sub-populations in the northern Okhotsk Sea because of almost permanent partial mixing of these groups.

Development of Agriculture, Hunting, Fishing and Reindeer Herding in Magadan Region in 1954–1957

The article, based on archival materials, examines the development of agriculture and commercial sectors in the Magadan Region during the crucial transitional period of 1954–1957, when the region coexisted with Dalstroy after the establishment of the Magadan Oblast. It analyzes measures taken by authorities to stimulate, modernize technologically and support financially the agricultural sector and commercial sectors in the region, as well as dynamics of key production, economic and social indicators in such vital areas of rural economy as reindeer herding, fur farming, crop production, animal husbandry, fur trapping, marine and river fishing and sea mammal hunting. Despite undertaken efforts and achievements, the development of the industry was hampered by insufficient financing, lack of equipment and infrastructure, and shortage of qualified personnel. The leading sector remained reindeer herding, which provided up to a third of all cash income of collective farms. However, this sphere also saw declining productivity and performance indicators. The volumes of fur trapping and sea mammal hunting decreased substantially. Problems in many areas of agriculture and commercial sectors were associated with the elimination of Dalstroy's organizational units. The transitional period was characterized by stagnation in the development of agricultural and commercial sectors in the region.

The past and present of breeding in dairy cattle breeding in the Far North-East

Based on historical facts and past achievements, the work is designed to update the importance and prove the possibility of successful breeding work at the regional level in order to increase the production of high-quality, socially significant food products to ensure food security. At the beginning of the formation of agricultural science in the Magadan region, scientists were faced with the task of selecting the optimal breeds for the region. More than 4000 cows were examined during 1964–1967. It was found that in extreme natural and climatic conditions of the Magadan region the Kholmogory breed proved to be the best one. In 1967, in order to further improve the Kholmogory breed, the first attempt was made to study the genealogical structure of the herd, to identify and evaluate highly productive lines. In 1974, in order to increase the milk fat content of crossbred cows of the Kholmogory breed, introductory crossing with the bulls of the Ayrshire breed, tested for the quality of the offspring, was used. In order to improve dairy herds, the selection of cows for hereditary traits is combined with checking them for the first lactation. Since 1976, state farms began to study the breeding and productive qualities of the Ayrshire cattle, which were distinguished by high milk production and high fat content in milk. Since 1982, the Ayrshire breed has been approved as a planned breed for breeding in the farms of the Okhotsk zone. In the same year, absorptive crossbreeding of the animals of the Kholmogory breed with the sires of the Ayrshire breed began. In order to increase the efficiency of breeding for abundant milk production, work began on the farms to increase the hereditary variability of this trait through breeding along lines and families. At the same time, the work on improving the Kholmogory cattle by introductory crossbreeding with the purebred bulls of the Holstein-Friesian breed continued. By the 1990s, the main vector of development was the creation of highly productive herds of dairy cattle, but the difficult financial situation at farms in the 1990s led to a sharp decrease in the number of cattle and the productivity of the remaining animals.

A key to the Russian species of the genus Coenosia Meigen (Diptera, Muscidae), with the description of one new species and new synonymies.

Identification keys to males and females are provided for the 77 species of the genus Coenosia Meigen, 1826 known from Russia, including one new species from the Magadan region (Coenosia luxia sp. nov.), and also Macrorchis meditata (Falln, 1825). Coenosia nevadensis Lyneborg, 1970 and Coenosia penicillata Hennig, 1961 are newly recorded in Russia. Coenosia paludis Tiensuu, 1939 and Coenosia ukokensis Sorokina, 2009 are newly recorded for the Far East. Two new synonymies are proposed: Hoplogaster morrisoni Malloch, 1924 syn. nov. of Anthomyza cingulipes Zetterstedt, 1849; Coenosia brevicauda Pont in Pont, Werner & Kachvoryan, 2005 syn. nov. of Coenosia nevadensis Lyneborg, 1970. Images of some species and of the male terminalia are given.

SEISMICITY of the NORTH-EAST of RUSSIA in 2018–2019

The results of seismic monitoring of the Magadan region, Chukotka Autonomous Area and the shelf of adjacent Okhotsk, Chukchi, Bering and East Siberian seas are considered. There were 14 seismic stations working in the region. The catalog includes information about 644 earthquakes with energy classes KR=4.8–13.2. As usual, most of them (77 %) are localized in the Kolyma region (area № 2).The additional catalog contains information about 12 earthquakes in the Chukchi. The total seismic energy released within the region’s borders was ΣЕ=2.671013 J. The classification of Russian North-East earthquakes was performed using energy classes KR of T.G. Rautian’s scale. According to the earthquake energy representativeness map, the regional network of stations records without omissions the earthquakes with Kmin=7on the territory of Magadan region, with Kmin=8 in the Okhotsk sea and with Kmin=10 in the Chukchi. The strongest earthquake of 2018–2019 with KR=13.2 (MPSP=5.1, MS=4.0) occurred on July 5, 2019 in in the Kolyma area. 14 earthquakes with intensity I=2–5 of the Russian Seismic Intensity Scale (SIS-2017) were felt in North East settlements. Epicenters of Magadan region earthquakes were plotted on the tectonic zoning scheme. Most earthquakes are confined to the largest deep faults in the northwestern and sublatitudinal directions. All hypocenters are located within the earth's crust. The seismicity level of the North-East of Russia in 2018–2019 according to the “SOUS’09” scale was assessed as "background average one" for the observation period from 1968 to 2019. Spatially, all earthquakes in the North-East of Russia are traditionally concentrated in large seismogenic belts: Chersky, North-Okhotsk and Trans-Beringian.

МОРФОЛОГИЧЕСКИЕ ХАРАКТЕРИСТИКИ, ХИМИЧЕСКИЙ СОСТАВ РОССЫПНОГО ЗОЛОТА БАССЕЙНА РЕКИ КЕНГЕВЕЕМ И ПЕРВЫЕ СВЕДЕНИЯ О СОПУТСТВУЮЩЕЙ ПЛАТИНОВОМЕТАЛЛЬНОЙ МИНЕРАЛИЗАЦИИ (МАГАДАНСКАЯ ОБЛАСТЬ)

The paper presents the results of the study of typomorphic characteristics of placer gold of the tributaries of the Kengeveem River, Magadan region. Placer gold was studied by optical and scanning electron microscopy at the Institute of Volcanology and Seismology of the Far East Branch of the Russian Academy of Sciences. As a result, the first information on the morphology, internal structure and chemical composition of placer gold from the southeastern part of the Taigonos Peninsula was obtained. Three types of the gold were determined. The first type is dominant. The grains are chacterized by sub-ore morphology, with weak and medium degrees of roundness. Only Au-Ag is present in the composition of native gold, other macrocomponents were not found. The gold grade is 750–950 ‰. Some gold grains bear signs of hypergene transformation, expressed in the development of high-grade gold rims and intergrain veins. The second type of gold is represented by well-rounded lamellar extractions with a grade of 980–990 ‰. The third type is loose aggregates of secondary high-grade mustard gold. The obtained data allowed us to determine the different drift distances of native gold and to consider the low-sulfide epithermal Au-Ag mineralization and presumably far-distant gabbroids as the primary sources of gold.

The Mineralogical and Geochemical Features of the Early Cretaceous Gold Ore Mineralization of the Eastern Flank of the Yana–Kolyma Orogenic Belt (Magadan Region, Russia)

The Mineralogical and Geochemical Features of the Early Cretaceous Gold Ore Mineralization of the Eastern Flank of the Yana–Kolyma Orogenic Belt (Magadan Region, Russia)