The paper presents new original data on the Devonian rift-related volcanism from the Rudny Altai, a marginal terrane of the Siberian continent (Altai-Sayan Fold Belt, western Central Asian Orogenic Belt). The extensional regime in relation to tectono-magmatic reactivation of the continental margin was accompanied by an intense flare up of bimodal-type shallow-marine volcanism and injection of subvolcanic intrusions. On the first stage basic magmatism evolved from (i) injection of "More LREE- and HFSE-enriched" dolerite (epsilon(Nd)(t) = +5.1) to (ii) eruption of their effusive analogues (epsilon(Nd)(t) = +1.4), and following "Less LREE- and HFSE-enriched" basalt (epsilon(Nd)(t) = +6.1). This stage reflects initial opening of the rift. On the second stage, volcanism evolved from (iii) "LREE- and HFSE-depleted" (epsilon(Nd)(t) = +5.4) to (iv) "LREE-enriched and HFSE-depleted" (epsilon(Nd)(t) = +4.1 to +4.7) types. This stage correspond to the prolonged opening of the pull-apart basin, as there is no geological evidence for island-arc uplift during this period. Variations in indicator HFSE ratios (Th/Yb, Nb/Yb and Zr/Y), enrichment of Nb relative to La and Th in combination with moderate Nd isotopic values resemble those for basalts from the behind-arc region with close spatial-temporal relation to rifting. The trace element variation indicates a change in the partial melting degree of the mantle source, from lower to higher, consistent with progressive rifting. The petrogenesis of magmas has been interpreted as shallow melting of a lithospheric mantle, metosomatised by a previous subduction event, and inherited geochemical signatures of relict mantle. The voluminous felsic magmatism was formed by crustal melting during lithospheric extension when basic magmas reached high crustal levels. The dacites yield zircon U-Pb ages of ca. 375 Ma, reflecting the peak of volcanic activity. The tectonic record bear evidence of strike-slip deformation, which could been induced by translation of arc and back-arc lithospheric plates. Summary: The Devonian evolution of the Altai Convergent Margin (NW Rudny Altai) of the Siberian continent was accompanied by the generation of basalt-dacite volcanism (similar to 380-375 Ma). Based on the sequence of volcanic phases and their geochemical variations in the time range, two stages corresponding to the initial and longterm opening of the pull-apart basin are distinguished. The petrogenesis of the magmas is interpreted as shallow melting of lithospheric mantle metasomatised by a previous subduction event and inheriting geochemical signatures of the relict mantle. The initial and subsequent magmatic phases can be reproduced by varying the degree of partial melting of the magma source from lower to higher, consistent with the evolution of the pullapart basin. Rift-related magmatism is caused by arc and back-arc plate translation, with a minor role for subduction factor.

There are several large intrusions composed of 60–90

Приведены результаты комплексных исследований терригенных пород хабаровского аккреционного комплекса Сихотэ-Алиня. Установлено, что в обломках юрских и пермско-триасовых песчаников доминирует слабоокатанный и слабосортированный материал преимущественно из местных источников сноса. Обломочная часть пород представлена в основном кварцем, в меньшем количестве полевыми шпатами и обломками пород. Песчаники характеризуются повышенными содержаниями кремнезема, умеренной глиноземистостью, невысокими концентрациями фемических элементов и кальция, умеренными содержаниями щелочей при значительных вариациях K/Na отношения. Как для юрских, так и для пермско-триасовых пород типичны пониженные в сравнении с PAAS содержания LILE, РЗЭ, в меньшей степени HFSE и отрицательные значения параметра ɛNd(T). Модельный Nd возраст юрских песчаников варьирует от 1.36 до 1.71 млрд лет, пермско-триасовых — от 1.14 до 1.35 млрд лет. Большая часть популяции детритовых цирконов имеет позднепалеозойско-раннемезозойский возраст, примерно 25 % — более древний (до палеопротерозоя). Изученные песчаники являются преимущественно породами первого цикла выветривания (петрогенными), образованными при размыве магматических пород кислого состава. Синтез полученных данных позволяет считать, что главным источником кластического материала для мезозойских осадочных пород служили геологические комплексы северной части Бурея-Ханкайского супертеррейна (Буреинский и Малохинганский блоки), а также, возможно, восточной части Монголо-Охотского пояса. Хабаровский террейн не претерпел значительных перемещений по сдвигам системы Тань Лу и является «автохтонным» блоком в современной структуре Сихотэ-Алиня. The results of comprehensive studies of terrigenous rocks of the Khabarovsk Sikhote-Alin accretionary complex are presented. It is established that the fragments of Jurassic and Permian–Triassic sandstones are dominated by poorly rounded and poorly separated material mainly from local provenance areas. The detrital part of the rocks is mainly represented by quartz, in a smaller amount by feldspar and rock fragments. Sandstones are characterized by high silica content, moderate alumina content, low concentrations of femic elements and calcium, moderate alkali content with significant varia-tions in the K/Na ratio. Both Jurassic and Permian–Triassic rocks are typically characterized by reduced contents of LILLE, REE, to a lesser extent HFSE and negative values of the ɛNd(T) parameter – compared to PAAS. The model Nd age of Jurassic sandstones varies from 1.36 to 1.71 Ga, Permian–Triassic — from 1.14 to 1.35 Ga. Most of the detrital zircon population is of late Paleozoic–early Mesozoic age, approximately 25% are older (pre-Paleoproterozoic). The studied sandstones are mainly rocks of the first cycle of weathering (petrogenic), formed during the erosion of igneous rocks of felsic composition. The synthesis of the obtained data suggests that the main source of the cluster material for the Mesozoic sedimentary rocks was the geological formations of the northern part of the Bureya-Khanka superterrane (Bureya and Malokhingan blocks), as well as, possibly, the east-ern part of the Mongol-Okhotsk belt. The Khabarovsk terrane has not drifted significantly along the Tan Lu stike-slip system and is an “autochthonous” block in the present-day struc-ture of Sikhote-Alin.

The results of comprehensive studies of terrigenous rocks of the Khabarovsk Sikhote-Alin accretionary complex are presented. It is established that the fragments of Jurassic and Permian-Triassic sandstones are dominated by poorly rounded and poorly separated material mainly from local provenance areas. The detrital part of the rocks is mainly represented by quartz, in a smaller amount by feldspar and rock fragments. Sandstones are characterized by high silica content, moderate alumina content, low concentrations of femic elements and calcium, moderate alkali content with significant variations in the K/Na ratio. Both Jurassic and Permian-Triassic rocks are typically characterized by reduced contents of LILE, REE, to a lesser extent HFSE and negative values of the epsilon(Nd)(T) parameter - compared to PAAS. The model Nd age of Jurassic sandstones varies from 1.36 to 1.71 Ga, Permian-Triassic - from 1.14 to 1.35 Ga. Most of the detrital zircon population is of late Paleozoic-early Mesozoic age, approximately 25% are older (pre-Paleoproterozoic). The studied sandstones are mainly rocks of the first cycle of weathering (petrogenic), formed during the erosion of igneous rocks of felsic composition. The synthesis of the obtained data suggests that the main source of the cluster material for the Mesozoic sedimentary rocks was the geological formations of the northern part of the Bureya-Khanka superterrane (Bureya and Malokhingan blocks), as well as, possibly, the eastern part of the Mongol-Okhotsk belt. The Khabarovsk terrane has not drifted significantly along the Tan Lu stike-slip system and is an "autochthonous" block in the present-day structure of Sikhote-Alin.

The present paper considers petrographic and geochemical features of rocks of the Tigrinoe and Zabytoe stocks, provides their mineral composition, the results of the detailed study of micas and mineral-forming inclusions in quartz. It is shown that the development of ore-magmatic systems (OMSs) of the Zabytoe and Tigrinoe deposits is associated with the same rare-metal Li–F melts. It is confirmed that granitoids of the Tigrinoe stock can be considered as more differentiated analogs of granitoids of the Zabytoe stock. New data concerning the differences in the history of the magmatic stage of development of the OMSs of these deposits are presented. The evolution of melts of both deposits took place at high fluid pressure. Differences in the scale of ore mineralization of the two RMSs under consideration could be due to different fluid regime of magmatic sources evolution and more significant participation of transmagmatic fluid flows in the development of the Tigrinoe OMS.

--The paper presents data from a comprehensive study of granitoids identified in the Mayorka intrusion that is located in the western part of the Altai Mountains. It is shown that the massif is composed of rocks of four intrusive phases, the age of these rocks ranges from 391 to 372 Ma, and the intrusion of the main volume of granitoids dates back to a relatively short interval of 386-384 Ma. The massif contains rocks of two geochemical types. The first type is differentiated calc-alkaline granite-leucogranites with near-clark contents of high-field-strength elements and rare earth elements: epsilon(Nd)(T) = + 4.3 & mldr;+ 4.5 and sigma O-18 V-SMOW = +10.7 & mldr;+11.2 parts per thousand. The second is alkaline and moderately alkaline A-type alyaskites, strongly enriched in high-field-strength elements and rare earth elements, having epsilon(Nd)(T) + 5.3 and sigma O-18 V-SMOW = +11.6 parts per thousand. Granitoids of the first group are of crustal source, while the rocks of the second group contain a significant portion of mantle material. The near-simultaneous introduction of these melts to the level of formation of the intrusion causes their interaction and the formation of hybrid magmas. Low crystallization temperatures of granitoids (<700 degrees C) and the presence of syngenetic melt and fluid inclusions in most rock varieties indicate a high fluid saturation of the melts. The abundance of leucogranites, whose geochemical characteristics cannot be explained from the standpoint of shallow differentiation of primary magmas, indicates the leading role of fluid-magmatic interaction processes in the formation of high-silica magmas.

The results of geological, geochemical, and isotopic–geochronological studies of Late Devonian granitoids of Rudny Altai, which formed at the Hercynian stage of tectonogenesis of the Altai–Sayan sector of the Central Asian Fold Belt, are presented. The isotopic U–Pb age of zircons ranges from 367 to 363 Ma. The geochemical characteristics indicate that leucogranites belong to high-K calc-alkaline series (SiO2 > 73 wt

This paper presents data on the geological position, geochemical features, main mineral composition (micas, feldspars), and melt and fluid inclusions in quartz from Aba high-silica leucocratic granitoids in the western part of the Talitsa batholith, Russian Altai. According to these new geochemical data, the granitoids are classified as S-type, meaning they are formed via the partial melting of metasedimentary source rocks. Geological data and oxygen isotope composition analysis indicate that major-phase granitoid magma evolution took place at the level of intrusion formation, whereas the parent melt of late-phase leucogranite evolved in a deeper chamber. The geochemical features (HFSE and REE, and REE spectra) of the granitoids indicate significantly higher differentiation in the late leucocratic phase. The presence of coexisting syngenetic melt and fluid inclusions shows that leucogranite magma was already saturated with volatiles in the early crystallization stages. Based on the new data presented in this work, the Aba rock formation is associated with the volatile saturation of magmatic melts, the exsolution of a fluid phase, and magma degassing.

Eastern Transbaikalia is a unique rare-metal province of Russia. Most of the studied deposits are associated with granitoid intrusions. Despite the high degree of knowledge of regional magmatism, a number of issues, related to both the belonging of specific massifs to magmatic complexes and the correlation of certain complexes within various structural-formation zones, remain. This paper compares the material composition and age of several petrotypical and parapetrotypical massifs, which are classified as Late Mesozoic complexes distributed within the Aginsk, Shilka, and Argun structural-formational zones of Eastern Transbaikalia. Based on the results of U–Pb dating, two stages of granitoid magmatism have been established: (1) the end of the Middle and the beginning of the Late Jurassic (163–156 Ma) and (2) the beginning of the Early Cretaceous (142 Ma). It is shown that the closely aged rocks of the Borshchovochnyi, Amudzhikan–Sretensk, and Shakhtama complexes have similar material characteristics, while the rocks of the Kukulbei complex (from three massifs) vary in composition. Elevated δ18O values (from +10.8 to +11.9‰) in the rocks of the Jurassic complexes indicate their formation mainly due to the melting of crustal material, and lower δ18O values (from +9.8 up to +10.3‰) in the Early Cretaceous granitoids suggest the contribution of a mantle source to their genesis.

The state of art of the mineral-resource base of strategic solid mineral deposits in Russia in general, and in Siberia in particular, is reviewed. Special attention is paid to the perspectives of the development of a resource base of Li, rare-earth metals (REMs), and ordinary and impact diamonds in Siberia. The characteristics of some deposits and scenarios of their exploration are estimated taking into account the quality of ores, geographical position, the state of infrastructure, and level of technologies of ore processing and the final product. The perspectives of the development of the Nb and REM resource base are assessed within the Tomtor pluton and the territory of the Udzha Uplift in general. The summarized results on multiannual regional field and laboratory studies of the distribution and variations in the composition of Cr-pyrope, which is most informative among index minerals for the recognition of the diamond potential of kimberlites and which was sampled from intermediate reservoirs of various ages of the Siberian Platform, are presented. Based on these results, the areas with possible new fields of potentially diamondiferous Middle Paleozoic kimberlites are revealed. The mineralogy of impact diamonds of the Popigai astrobleme and its explosion zone is described, and their technological characteristics are estimated. The visions of a new large region of the mining industry based on the strategic mineral resource base are substantiated for the territory of the Lena–Khatanga interfluve.

The analysis of the state of the mineral resource base of strategic types of solid minerals in Russia in general and in Siberia in particular has been carried out. Particular attention is paid to the prospects for the development of the resource base of lithium, rare earth metals, ordinary and impact diamonds in Siberia. The characteristics of a number of deposits and options for their development were assessed, taking into account the quality of ores, geographical location, the state of the infrastructure and the level of development of technologies for ore dressing and obtaining end products. The prospects for the development of the raw material base of niobium and rare earth metals within the Tomtor massif and the territory of the Udzha uplift as a whole are assessed. Summary results of long-term regional field and laboratory studies of the distribution and compositional variations of Cr-pyrope garnet, the most informative of the set of indicator minerals for determining the potential diamond content of kimberlites, selected from uneven-aged intermediate reservoirs of the Siberian Platform, are presented. Based on these results, areas within the platform were identified with signs of the presence of new fields of potentially diamond-bearing kimberlites of the Middle Paleozoic age. A mineralogical description and assessment of the technological characteristics of impact diamonds from the Popigai astrobleme and from the ejection zone in its frame is given. The prospects of creating a new large area of the extractive industry on the raw material base of strategic materials in the territory of the Lena-Khatanga interfluve are substantiated

The article presents the results of the study of mineralogical and petrographic characteristics, composition and age of gabbroids and monzonitoids of the Burelomny Creek massif located in the Central Sikhote-Alin and spatially associated with the Tigriny rare-metal-granite intrusion, and Sn-W deposit. It is shown that the gabbroids and monzonitoids of the massif correspond to the high-potassium units of the normal and moderately alkaline series, and have low concentrations of titanium, high concentrations of phosphorus, moderate concentrations of HFSE and REE elements. The geochemical characteristics of the rocks indicate that their source combines lithospheric and sublithospheric mantle substrates and that they formed in the setting of a transform continental margin. The age of the gabbroids, determined by the Ar-Ar dating of a biotite monofraction, is 101+1.5 Ma and is synchronous with the "peak" of basite and granitoid magmatism in the Sikhote-Alin. A significant difference in age (more than 20 Ma) and discrepancy in geochemical specialization indicate that the Tigriny massif rare-metal granites, and associated mineralization have no genetic relationship with gabbroids and monzonitoids of the Burelomny Creek massif.

Н. Н. КрукБелорусский государственный технологический университет ФЕНОМЕНОЛОГИЯ МНОГОЦЕНТРОВЫХ МЕЖМОЛЕКУЛЯРНЫХ ВЗАИМОДЕЙСТВИЙ В ЯДРЕ МАКРОГЕТЕРОЦИКЛИЧЕСКИХ СОЕДИНЕНИЙВ работе представлено феноменологическое рассмотрение факторов, обуславливающих многоцентровый характер межмолекулярных взаимодействий в ядре макрогетероциклических соединений, различающихся строением макроцикла и архитектурой его периферического замещения, в конденсированной фазе.Отмечено, что асимметрия молекулярной структуры вносит основной вклад в различие реакционной способности центров одного типа.Обосновано описание состояния молекулярной системы с помощью функции, которая учитывает неэквивалентность реакционных центров и взаимодействие между ними

This article describes the geological setting, geochemical features of rocks and the composition of the main minerals (micas, feldspars) of the granitoids of the Tigriny intrusion (Central Sikhote-Alin), associated with Sn-W mineralization. It is shown that the granitoids have high contents of fluorine and typomorphic trace elements and geochemically correspond to Li–F rare-metal granitoids. The evolution of rare-metal-granite magmas of the Tigriny massif was controlled by two main processes: fluid–magmatic interaction, which led to the formation of ultrapotassic pegmatoid granites, stockscheiders, and crystallization differentiation along the albite “trend,” which led to the formation of lower-silica aluminous sodic melts of the final phase. The latter were likely emplaced in an open or partially open-system conditions and experienced intense degassing during crystallization, which resulted in the formation of late plagioclase granites with lower contents of fluorine and typomorphic trace elements as compared to the earlier rocks. Separation of high-F fluids enriched in trace alkalis and ore components led to the formation of the large Tigrenok greisen body, which hosts the main volume of the richest ores of the Tigriny deposit.

This work contains an analysis of the total content of petroleum products (hydrocarbons) in samples and columns of bottom sediments (BS) of the Noril’skaya–Pyasino group of water objects contaminated as a result of a diesel fuel spill from the CHPP-3 reservoir at AO NTEC near Norilsk. Two methods—fluorimetry and gas chromatography—have been used for analysis. Gas chromatography is also used to obtain the distribution of n-alkanes in extracts from BS and study the contribution of hydrocarbons (HCs) of diesel fuel and of slightly mature organic matter from modern sediments in the total content of HCs. The HC composition of diesel fuel and of chloroform extracts from BS is determined. It is shown that the pollution of BS in Lake Pyasino with HCs is insignificant when compared with their background content, and the maximal pollution is revealed for BS in the Ambarnaya River.

More than 30 mafic dykes crop out in the Sergeevka belt in the coastal South Primorye, Far East Russia, of which geologic settings have been unclear for years. This study conducted major‐ and trace elements characterization, Sr–Nd isotope analyses, and Ar–Ar amphibole and U–Pb zircon datings for these rocks in order to identify their origin. The results demonstrated that all dykes are characterized by high Ba/Yb and low Nb/Y, Zr/Y, and Th/Yb ratios, which suggest their origin from arc melts derived from thin wedge mantle and shallow‐dipping slab. These dykes are clearly separated into two distinct age/geochemistry suites; that is, the Paleogene and Early Cretaceous one with dolerites/basalts and adakitic rocks, and the Permian–Triassic one with high‐Mg and high‐Al gabbro‐dolerite varieties. Their geochemistry suggests that the older suite was sourced from a primitive depleted MORB mantle (DMM)‐type mantle, whereas the younger suite from an enriched mantle II (EM2)‐type mantle domain. The transition in source type from DMM to EM2 occurred during the Jurassic‐earliest Cretaceous time, probably by a strong influence of a mantle plume onto the long‐continuing subduction‐related magmatism. The plume influence reached the maximum when the unique meimechite‐picrite complex formed in the region.

This is a synthesis of published and new data on the Kalba batholith in Eastern Kazakhstan, the large granitic body in the western part of the Central Asian Orogenic Belt. The batholith consists of granodiorite-granite and leucogranite rocks discriminated on the basis of major-and trace-element chemistry and isotope systematics. The granodiorite-granite rocks, which form the bulk of the batholith, are compositionally variable and can be classified as mixed S-I-type granites. The leucogranites occurring as a few large intrusions in the northwestern part of the batholith have more stable compositions, with high contents of REE, HFSE, F, Li, and B, typical of A-granites. Judging by the isotope systematics of the Kalba granites, compared with that of their potential parent rocks from the Kalba-Narym zone and its surroundings, the two groups originated by different mechanisms in two magmatic events. The granodiorite-granites were produced by large-scale melting of crustal material, including the metabasaltic basement and overlying metavolcanic and metasedimentary rocks. The origin of leucogranites was associated with low-degree partial melting of the deepest Kalba-Narym sediments under the effect of fluoride fluids. The batholith formation spanned about 21 myr: granodiorites and granites formed in the 297-286 Ma interval and leucogranites between 288 and 276 Ma. The ages of the two events bracket the intraplate postorogenic stage of the CAOB history that was coeval to the formation of the Tarim large igneous province. (c) 2021 Elsevier B.V. All rights reserved.

Late Paleozoic - earlyMesozoic geological evolution of the Kolyvan-Tomsk Fold Zone (KTFZ) located in the northwestern part of the Central Asian Orogenic Belt is significant to understanding the tectonic transition from postcollision to intraplate settings. We present new whole-rock geochemical and Sr-Nd isotopic data, and in situ zircon U-Pb ages for granitic rocks from the KTFZ basement to constrain their petrogenesis and to characterize changing of the tectonic setting and geodynamic evolution. Zircon U-Pb ages reveal extended multi-stage emplacement of the KTFZ granitoids for about 20 Ma from similar to 260 to similar to 240 Ma, that can be divided into two stages: the Permian-Triassic (similar to 260 to 250 Ma) and the Triassic (similar to 250 to 240 Ma). The Permian -Triassic granitic rocks with SiO2 between 63% and 74% have high LREE, HFSE (except Nb and Ta), Sr, Mg#, Cr, Ni concentrations, Sr/Y and (La/Yb)(N) ratios and remarkably low Y and Yb contents and Sr-87/Sr-86((T)) values (0.704682 and 0.703368). They are magnesian and show metaluminous to weakly peraluminous natures, indicating their formation through high degree fractionation of mantle-derived magmas. The Triassic granitoids exhibit extremely high SiO2 (73-77%), HFSE, HREE, Rb contents, Rb/Sr ratios and elevated negative Eu and Sr anomalies, low Mg#. They are ferroan and have a peraluminous nature with the absence of aluminium-rich minerals, all of which indicate the presence of the crustal substance in the magma source. Isotopic Nd compositions show that the both the Permian -Triassic and Triassic granitoids have uniform magma's, whichwere derived frompartialmelting of juvenile Neoproterozoic sources. These two stages of granitoid magmatism are interpreted as reflecting the transition from post-collisional magmatism, related to the final closure of the Paleo-Asian Ocean due to collision between the Baltica and Siberian paleocontinents during the Late Permian - Early Triassic and hence, to the intraplatemagmatism. The formation of the KTFZ granitic rocks was induced by an upwelling asthenosphere in an extensional geodynamic setting. During the post-collisional process, the large-scale lithospheric delamination plays a key role in the genesis of the Permian-Triassic granitoids and provide the magma generation for them. In the Triassic, we propose additional source of heat from mantle plume beneath the KTFZ, which promote extending of the granitoid magmatism in intraplate setting. (C) 2021 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.