In the Severny pluton in Chukotka, an association of rare-metal, tin-bearing topaz-zinnwaldite greisens (zwitters) and tourmaline metasomatites has been identified through geological mapping and mineralogical-petrographic studies. These formations are genetically linked to magmatism producing Li-F granite intrusions. The distribution and composition of zwitters and muscovite-quartz-tourmaline metasomatites forming halos around quartz-tourmaline veins were investigated. A wide spectrum of tourmaline mineral species was established, occurring in pegmatoid pockets of leucogranites (tourmaline I), pre-ore quartz-tourmaline metasomatite veins with fluorite (tourmaline II), early ore quartz-tourmaline metasomatite veins (tourmaline III), and ore tourmaline and quartz veins (tourmaline IV). An evolution of tourmaline from Sc-bearing fluor-schorl in pre-ore metasomatites to oxy-schorl and tin-bearing ferro-bosiite in tin-ore metasomatites was revealed, with a gradual increase in lithium content and variable iron oxidation state. In zwitters, muscovite-quartz-tourmaline metasomatites, and tourmalinite veins, a combination of tin and rare-metal mineralization is noted. The research results can be used to assess the metallogenic potential and develop criteria for forecasting rare-metal (Nb, Ce, Y, W, Bi) mineralization in the Severny pluton.

This study examines the accessory wodginite and the discovery of titanium-bearing wodginite and Fe and Ti-bearing wodginite in lithium-fluorine granites from the Abu Dabbab and Nuweibi massifs in Eastern Egypt. The wodginite group’s mineral association includes tantalum-bearing cassiterite and tin-bearing tantalum–niobate minerals: tantalite-(Mn), columbite-(Mn), and microlite. Three forms of wodginite crystallization were identified: (1) rims around columbite-(Mn) and tantalite-(Mn) varying from 1.5 to 21.9 μm in thickness, (2) micro-inclusions in cassiterite ranging from 5.4 to 27.0 μm in size, and (3) autonomous crystals measuring 3–124 μm in length. Wodginite in the Nuweibi massif is mainly found in porphyritic granite of late-stage porphyry intrusion. It has a similar composition to the worldwide wodginite of rare-metal granites, but exhibits a lower content of TiO2 (average 0.54%) and is a mineral indicator of rich tantalum ore deposits. In contrast, wodginite in the Abu Dabbab massif is replaced by titanium-bearing wodginite (Ti/(Sn + BTa + Ti + Fe3+) = 0.23) and is associated with Fe and Ti-bearing wodginite. Wodginite and Ti-bearing wodginite are maximally enriched in manganese (Mn/(Mn + Fe2+ +Ca) = 0.95), expressed in all intrusive phases of the massif, and are mineral indicators of tantalum-bearing granites with associated cassiterite-quartz mineralization.

Li-F granites from the Kester deposit (Yana Plateau in Yakutia, Russia) are proved to be connected with a rare-metal complex of accessory minerals: montebrasite, columbite-(Mn), columbite-(Fe), tantalite-(Mn), Ta-bearing cassiterite, U-bearing microlite, W-bearing ixiolite, niobian ferberite, U–Hf-rich zircon, and Ta-bearing rutile. Accessory wodginite was discovered at depths of up to 150 m in association with tantalite-(Mn), columbite-(Mn), and cassiterite. According to the content of WO3 (1.23%–3.33%) and the values of Mn/(Mn + Fet) and Ta/(Ta + Nb), Yakut wodginite is an intermediate mineral between wodginite and a hypothetical mineral of the wodginite group—”wolframowodginite”. The discovery of tungsten-bearing wodginite at the Kester deposit confirms the widespread presence of tungstic and tungsten-bearing accessory minerals in Li-F granites in the Russian Far East. It also serves as an indicator of rare-metal tin-tantalum-bearing granites and pegmatites.

In the composition of tantalum-niobates, the tin-bearing wodginite group minerals (WGM) were found: wod-ginite, titanowodginite, ferrowodginite, ferrotitanowodginite, lithiowodginite, tantalowodginite, “wolframowodginite”. We reviewed the worldwide research on WGM and created a database of 698 analyses from 55 sources including the author's data. WGM are associated with Li-F pegmatites and Li-F granites. Wodginite is the most prevalent mineral, occurring in 86.6 % of pegmatites and 78.3 % of granites. The occurrence of WGM in granites and pegmatites differs. For instance, titanowodginite and “wolframowodginite” occur three times more frequently in granites than in pegmatites, whereas lithiowodginite and tantalowodginite do not appear in granites at all. The difference between WGM in granites and pegmatites is in finer grain size, higher content of Sn, Nb, Ti, W, and Sc; lower content of Fe3+, Ta, Zr, Hf; higher ratio of Mn/(Mn + Fe); and lower ratio of Zr/Hf. The evolutionary series of WGM in pegmatites are as follows: ferrowodginite → ferrotitanowodginite → titanowodginite → “wolframowodginite” → wodginite → tantalowodginite; in granites: ferrowodginite → ferrotitanowodginite → “wolframowodginite” → wodginite → titanowodginite. WGM can serve as indicators of tantalum-bearing pegmatites and granites. In Russia the promising sources of tantalum are deposits of the Far Eastern belt of Li-F granites containing wodginite.

The complex of sulfostannates from the Pravourmiyskoye greisen deposit in the Far East of Russia is discussed. The complex includes stannoidite, mawsonite, stannite, sakuraiite. The discovery and typomorphic features of ferrokësterite and kësterite are noted. Zwitter-tourmalinite metasomatic complexes accompanying the lithium-fluoric granites are distinguished by high ore fertility and lithochalcophilic specialization. They combine cassiterite, wolframite, sulfides (arsenopyrite, lollingite, chalcopyrite, bornite, sphalerite, pyrrhotine, bismuthinite, etc.) and sulfostannates with an admixture of In, Ag, Cd. It is proposed to use sulfostannates as minerals indicating large-scale formation of rare-metal-tin ore.

This paper is a scientific overview of studies of accessory cassiterite from rare metal granites, pegmatites, and accompanying greisens in 1990–2021. The earlier and newest data on the morphology, physical and chemical features of accessory cassiterite, and its economic facility are summarized. The consolidated database includes 1759 cassiterite compositions from more than 100 publications. We have confirmed previous and identified new indicator features of cassiterite from rare metal granites, pegmatites, and greisens: concentrations of isomorphous components (Ta, Nb, Fe, Ti, Mn, W, Sc, In, Zr, Hf, U), informative ratios (Nb/Ta, Zr/Hf, Fe/Mn), and main substitution schemes (“tapiolite” and “hydrothermal”). The average trace element content in cassiterite from granites, pegmatites, and greisens is 6.68, 4.87, and 1.18 wt

The evolution and ore content of granitoid magmatism in the Far East belt of lithium-fluoric granites lying in the Russian sector of the Pacific ore belt have been studied. Correlation of intrusive series in the Novosibirsk-Chukotka, Yana-Kolyma and Sikhote-Alin granitoid provinces of the studied region allowed to establish the unity of composition, evolution, and ore content of the Late Mesozoic granitoid magmatism. On this basis, a model of the type potentially ore-bearing intrusive series of the Far East belt of lithium-fluoric granites has been developed: complexes of diorite-granodiorite and granite formations → complexes of monzonite-syenite and granite-granosyenite formations → complexes of leucogranite and alaskite formations → complexes of rare-metal lithium-fluoric granite formation. The main petrological trend in granitoid evolution is increasing silicic acidity, alkalinity, and rare-metal-tin specialization along with decreasing size and number of intrusions. At the end of the intrusive series, small complexes of rare-metal lithium-fluoric granites form. The main metallogenic trend in granitoid evolution is an increasing ore-generating potential of intrusive complexes with their growing differentiation. Ore-bearing rare-metal-granite magmatism of the Russian Far East developed in the Late Cretaceous and determined the formation of large tungsten-tin deposits with associated rare metals: Ta, Nb, Li, Cs, Rb, In in areas with completed intrusive series. Incompleteness of granitoid series of the Pacific ore belt should be considered as a potential sign of blind rare-metal-tin mineralization. The Far East belt of lithium-fluoric granites extends to the Chinese and Alaskan sectors of the Pacific belt, which allows the model of the type ore-bearing intrusive series to be used in the territories adjacent to Russia.

Three mineral species of the columbite group were installed at the Kester deposit (Eastern Yakutia): columbite-(Fe), columbite-(Mn) and tantalite-(Mn), which are part of rare-metal granites and ongonites, albitites and greisens. Columbite-(Mn) prevails: Ta/(Ta + Nb) = 0.30, Mn/(Mn + Fe) = 0.64. The generalized formula for the columbite-tantalite of deposit is (Mn0.61Fe0.34)0.95(Nb1.37Ta0.58Ti0.04W0.03Sn0.01)2.03O6. Columbite tantalite combine the polymineral individuals with concentric growth zonality (from core to rim): columbite-(Fe) → columbite-(Mn) → tantalite-(Mn) + uranmicrolite → columbite-(Mn). A typomorphic impurity in the columbite of Kester deposit – WO3: an average of 2.67 % (apfu 0.04); maximum 7.12 % (apfu 0.11). Isomorphic substitution of cations in position B is assumed according to the scheme: 2(Nb,Ta)5+ ↔ W6+ + Ti4+. Typomorphic impurity in tantalite – SnO2: on average 1.01 % (apfu 0.03); maximum 3.74 % (apfu 0.21). Paragenesis of columbite-group minerals includes: albite, topaz, lepidolite, Nb-Ta-containing cassiterite, wolframoixiolite, wolframite, U-Hf-containing zircon, struverite. The evolution of columbite-tantalite of the Kester deposit is accompanied by an increase in the relations of Ta/Nb, Mn/Fe, Sn/W, expressed in the change of columbite by tantalite both in the process of formation of ore-bearing rocks and in the series of these rocks: rare-metal granites → albitites → greisens. Fluctuation limits of ratios Ta/(Ta + Nb) 0.07–0.74, Mn/(Mn + Fe) 0.16–0.96. The diversity and evolution of the columbite-group minerals of Kester deposit indicate their belonging to the rare-metal ore- magmatic system, which includes ore-bearing rare-metal granites, albitites and greisens. The presence of the small intrusions of rare-metal granites and ongonites in the area of the deposit allows predicting the discovery of new objects of bed-rock and placer columbite-tantalite mineralization.

Исследована эволюция и рудоносность гранитоидного магматизма Дальневосточного пояса литий-фтористых гранитов, расположенного в российском секторе Тихоокеанского рудного пояса. Корреляция интрузивных серий в Новосибирско-Чукотской, Яно-Колымской и Сихотэ-Алинской гранитоидных провинциях исследованного региона позволила установить единство состава, эволюции и рудоносности позднемезозойского гранитоидного магматизма. На этой основе разработана модель типовой потенциально рудоносной интрузивной серии Дальневосточного пояса литий-фтористых гранитов: комплексы диорит-гранодиоритовой и гранитовой формаций → комплексы монцонит-сиенитовой и гранит-граносиенитовой формаций → комплексы лейкогранитовой и аляскитовой формаций → комплексы формации редкометалльных литий-фтористых гранитов. Главный петрологический тренд эволюции гранитоидов – нарастание кремнекислотности, щелочности и редкометалльно-оловянной специализации при уменьшении размеров и количества интрузий. В финале интрузивных серий происходит становление малообъемных комплексов редкометалльных литий-фтористых гранитов. Главный металлогенический тренд эволюции гранитоидов – увеличение рудогенерирующего потенциала интрузивных комплексов с ростом их дифференцированности. Рудоносный редкометалльно-гранитовый магматизм Дальнего Востока России развивался в позднем мелу и определял формирование в районах с завершенными интрузивными сериями крупных вольфрамово-оловянных месторождений с попутными редкими металлами: Ta, Nb, Li, Cs, Rb, In. Незавершенность гранитоидных серий Тихоокеанского рудного пояса следует рассматривать как потенциальный признак слепого редкометалльно-оловянного оруденения. Дальневосточный пояс литий-фтористых гранитов продолжается в китайском и аляскинском секторах Тихоокеанского пояса, что позволяет использовать модель типовой рудоносной интрузивной серии на сопредельных с Россией территориях

The typomorphic features and origin of the ferrokësterite and kësterite sulfostannates from Li–F granite-related greisen ore deposits of the Russian Far East are discussed. The composition of kësterite from the greisens at its type locality, the Këster deposit (Yakutia), is described. The parameters of the mineral correspond to the earlier descriptions. Special attention is given to the localization and composition of ferrokësterite found in the greisens (zwitters) of the Pravourmiyskoye deposit (the Amur River region). This ferrokësterite is characterized by a high Fe/(Fe + Zn) ratio in the range of 0.73–0.92 and deficiency in In, Ag, Cd, Bi, As, and Se impurities. Kësterite and ferrokësterite are associated with cassiterite, sphalerite, pyrrhotite, and arsenopyrite at the upper levels of greisen ore bodies, where they displace other sulfostannate minerals. A comparison between the kësterites and ferrokësterites from the Russian Far East and sulfostannates from the greisens associated with lithium–fluorine granites elsewhere around the world is made. It is proposed to consider kësterite and ferrokësterite as indicator minerals of large-scale rare-metal–tin minerageny. Ferrokësterite is a polymorphic modification of stannite. The boundary between kësterite and ferrokësterite is defined by a value of Fe/(Fe + Zn) of around 0.73. Ferrokësterite should be analyzed as a probable natural prototype of an optoelectronic material for solar cell manufacturing.

Abstract—The problem of the origin of “white granite” in the Kester harpolith of the Arga–Ynnakh–Khaya Pluton is discussed. The morphology, occurrence, and nature of the intrusive contacts of the Kester harpolith prove its magmatic origin. The petrographic and petrochemical properties of “white granite” allow its identification as a postorogenic rare-metal high-phosphorus granite of the Li-F geochemical type. The magmatic genesis of the “white granite” texture is supported by statistical methods. The composition, typomorphic properties, ontogenetic features internal structure and relationship of accessory minerals indicate that the major accessories of the granite, that is, cassiterite, columbite, tantalite, “wolframoixiolite,” zircon, and ferberite, were formed at the late stage of the low-temperature rare-metal granitic melt. The Kester harpolith within the Arga–Ynnakh–Khaya granite pluton and the eponymous tin–rare-metal deposit genetically related to it are a part of the Far East Superprovince of rare-metal granites.

Исследованы тектоно-магматические факторы локализации литий-фтористых гранитов Востока России. В основу исследования положены представления дальневосточных геологов о глубинных структурах внутриплитной активизации. Использована модель очаговой структуры с мантийными источниками тепла и рудогенерирующими магматическими комплексами. Проведен специальный металлогенический анализ Востока России в приложении к редкометалльно-оловоносной формации субщелочных лейкогранитов, в том числе литий-фтористых гранитов. Главным фактором тектоно-магматического развития Востока России, локализации рудогенерирующих гранитов и формирования редкометалльно-оловорудных районов являются очаговые структуры. На глубоких ярусах очаговых структур располагаются области разуплотнения мантии и земной коры, источники тепла, магм, флюидов и гранитоидные криптобатолиты. Вблизи современной поверхности сосредоточены относительно крупные массивы лейкогранитов, малые интрузии оловоносных монцонитоидов и литий-фтористых гранитов. Очаговые структуры соответствуют рангу рудного района. Приведены примеры очаговых структур на юге региона: Баджальская, Мяо-Чанская, Иппато-Мерекская, Хогду-Льянчлинская, Арминская и др.; на севере: Певекская, Куйвивеем-Пыркакайская, Куэквунь-Экиатапская, Иультинская, Телекайская, Центрально-Полоусная, Омсукчанская и др. Выделены три типа рудных районов по степени эрозионного среза очаговых структур и литий-фтористых гранитов. Намечены закономерности эволюции очаговых структур и место в геологической истории рудоносных гранитов. Предложена классификация очаговых структур и ее сопоставление с классификациями региональных интрузивных и металлогенических подразделений. Установлено, что, несмотря на многообразие тектонических и геолого-петрологических обстановок Востока России, интрузии литий-фтористых гранитов подчиняются единым тектоническим и магматическим факторам. Выделены и классифицированы тектоно-магматические факторы локализации литий-фтористых гранитов Востока России: геофизический, орогенный, геоблоковый, магматический, метасоматический и дизъюнктивный.

The purpose of the paper was to identify the causes of rock bumps that occurred at the Alardinskaya mine (Russia) in 2011. The research was carried out using the finite element method. The developed three-dimensional model of the rock mass included a coal seam, rocks bedding above and below, goaf, and a system of local preparatory workings. The situation that arose immediately before the first rock burst was modeled during the research - when the longwall crossed a diagonal entry. The performed investigations enabled the authors to make a conclusion about a high danger of using technological schemes for the development of seams by longwalls leaving pillars that have a width less than the length of the support pressure zone, especially due to diagonal entries. As a safe technology for the longwall development of seams prone to rock bursts, it is recommended to apply a technological scheme with the abandonment of wide barrier pillars and four preparatory workings in each section, which has proven itself in the processing of rock bump hazardous seams in the state of Utah (USA).

Three continuum models extending the conventional Navier–Stokes–Fourier approach for modeling the shock wave structure in carbon dioxide are developed using the generalized Chapman–Enskog method. Multi-temperature models are based on splitting multiple vibrational relaxation mechanisms into fast and slow processes and introducing vibrational temperatures of various CO2 modes. The one-temperature model takes into account relaxation processes through bulk viscosity and internal thermal conductivity. All developed models are free of limitations introduced by the assumptions of a calorically perfect gas and constant Prandtl number; thermodynamic properties and all transport coefficients are calculated rigorously in each cell of the grid. Simulations are carried out for Mach numbers 3–7; the results are compared with solutions obtained in the frame of other approaches: multi-temperature Euler equations, model kinetic equations, and models with constant Prandtl numbers. The influence of bulk viscosity and Prandtl number on the fluid-dynamic variables, viscous stress, heat flux, and total enthalpy is studied. Bulk viscosity plays an important role in sufficiently rarefied gases under weak deviations from equilibrium; in multi-temperature models, non-equilibrium effects are associated with slow relaxation processes rather than with bulk viscosity. Using a constant Prandtl number yields over-predicted values of the heat flux. Contributions of various energy modes to the total heat flux are evaluated, with emphasis on the compensation of translational–rotational and vibrational energy fluxes.

The purpose of the paper is to substantiate the width of the barrier and yield pillars for the application of a new seam development scheme in the conditions of the Alardinskaya mine (Russia). The Alardinskaya mine develops gas-bearing coal seams that are prone to spontaneous combustion and are hazardous due to rock bumps, which leads to frequent accidents. The analysis of the world experience of mining seams being hazardous to rock bumps showed that safe mining with longwalls can be provided by a system of inter-panel pillars: very wide barrier pillar and two yield pillars. Numerical modeling using the finite element method was carried out to assess the possibility of reducing the barrier pillar width in order to decrease the volume of coal losses in the subsoil. The model of rock massif was created in Ansys mechanical software. Numerical modeling of the longwall panel development with longwalls was carried out at various widths of broad and yield pillars. The analysis outcomes of the vertical stresses diagrams in the seams are presented for different parts of the longwall panel. The rational parameters of the pillar system, ensuring the minimization of the reference pressure influence from the previously worked-out column and the reference pressure of the operating longwall, are determined as a result of numerical analysis. The conclusion is made about the expediency of the technological scheme application proposed by the authors in the conditions of the Alardinskaya mine to reduce the endogenous fire hazard and the danger of rock bumps.

A complex of accessory W-bearing tantalo-niobates (columbite-(Fe), columbite-(Mn), tantalite-(Mn), microlite group minerals, and Ta-bearing rutile) involving “wolframoixiolite” has been found for the first time in Li–F granite and ongonite of the Arga–Ynnakh–Khaya Pluton in East Yakutia. The rocks that contain wolframoixiolite, as well as the composition and typical features of the mineral, are described: its high Fe concentration, the leading mineral-forming role of niobium, widely variable W and Ta contents, and paragenesis with W-bearing columbite-(Mn), Ta–Nb ferberite, lepidolite, and topaz. Wolframoixiolite from the Arga–Ynnakh–Khaya Pluton is formed by polymorphic transition of columbite-(Fe) at the late stage of Li–F granite crystallization. A review of accessory mineralization in rare-metal Li–F granites of Eurasia, taking the new finding into account, indicates that wolframoixiolite is a typical accessory phase in Li–F granites and may indicate rare-metal granite magmatism accompanied with tin–rare-metal mineralization.

The phenomenon of an abnormally high concentration of tantalum (5.3–17.9% of Ta 2 O 5 ) in accessory cassiterite from lithium–fluoric granites of the Arga-Ynnakh-Khaysky massif in East Yakutia is described. The significant isomorphic capacity of the cassiterite structure in relation to the tapiolite impurity, which reaches 15.1–39.8%, is established. It is concluded that the origin of tantalum-bearing cassiterite is determined by the specific crystallization conditions of lithium–fluoric granites, and their wide distribution in the Far East of Russia requires further study of the typochemistry of accessory cassiterite from rare-metal granites and genetically related metasomatites.

We investigated the deep structure of the lithosphere and the geodynamic conditions of granitoid magmatism in the Eastern Russia within the borders of the Far Eastern Federal District. The relevance of the work is determined by the need to establish the geotectonic and geodynamic conditions of the granitoids petrogenesis and ore genesis in the Russian sector of the Pacific Ore Belt. The purpose of the article is to study the deep structure of the lithosphere and determine the geodynamic conditions of granitoid magmatism in the East of Russia. The author's data on the magmatism of ore regions, regional granitoids correlations, archive and published State Geological Map data, survey mapping, deep seismic sounding of the earth's crust, gravimetric survey, geothermal exploration, and other geophysical data obtained along geotraverses. The magma-controlling concentric geostructures of the region are distinguished and their deep structure is studied. The connection of plume magmatism with deep structures is traced. The chain of concentric geostructures of Eastern Russia controls the trans-regional zone of leucocratization of the earth's crust with a width of more than 1000 km, which includes the Far Eastern zone of Li-F granites. Magma-controlling concentric geostructures are concentrated in three granitoid provinces: Novosibirsk-Chukotka, Yano-Kolyma, and Sikhote-Alin. The driving force of geodynamic processes and granitoid magmatism was mantle heat fluxes in the reduced zones of the lithospheric slab. The distribution of slab windows along the Pacific mobile belt's strike determines the location of concentric geostructures and the magnitude of granitoid magmatism in the regional provinces. Mantle diapirs are the cores of granitoid ore-magmatic systems. The location of the most important ore regions of the Eastern Russia in concentric geostructures surrounded by annuli of negative gravity anomalies is the most important regional metallogenic pattern reflecting the correlation between ore content and deep structure of the earth's crust.

Исследованы закономерности глубинного строения литосферы и геодинамические условия гранитоидного магматизма Востока России в границах Дальневосточного федерального округа. Актуальность работы определяется необходимостью установления геотектонических и геодинамических условий петрогенезиса гранитоидов и рудогенеза в российском секторе Тихоокеанского рудного пояса. Цель статьи – изучение элементов глубинного строения литосферы и определение геодинамических условий гранитоидного магматизма Востока России. Использованы авторские данные о магматизме рудных районов, корреляции гранитоидов региона, фондовые и опубликованные материалы Госгеолкарты, обзорного картирования, глубинного сейсмического зондирования земной коры, гравиметрических, геотермических съемок и другие материалы геофизических исследований вдоль геотраверсов. Выделены магмоконтролирующие кольцевые геоструктуры региона и изучено их глубинное строение. Прослежена связь плюмового магматизма с глубинными структурами. Цепочка кольцевых геоструктур Востока России контролирует трансрегиональную зону лейкократизации земной коры шириной более 1000 км, которая включает Дальневосточный пояс литий-фтористых гранитов. Магмоконтролирующие кольцевые геоструктуры сконцентрированы в трех гранитоидных провинциях: Новосибирско-Чукотской, Яно-Колымской и Сихотэ-Алинской. Движущей силой геодинамических процессов и гранитоидного магматизма являлись мантийные тепловые потоки в окнах разрыва литосферного слэба. Распределение астеносферных окон по простиранию Тихоокеанского подвижного пояса определяет размещение кольцевых геоструктур и масштабы гранитоидного магматизма в провинциях региона. Мантийные диапиры служат ядрами гранитоидных рудно-магматических систем. Размещение наиболее важных рудных районов Востока России в кольцевых геоструктурах с ареалами отрицательных аномалий силы тяжести – важнейшая региональная металлогеническая закономерность, отражающая связь рудоносности с глубинным строением земной коры.