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The article reveals the trend of mass loss of native speakers of the Russian language in post-Soviet Central Asia. Authors analyze the policies and objective trends in those states in detail, leading to the identified problem. The authors outline the growing trends in the replacement of the Russian language in domestic processes of communication with national languages, the diminishing role of the Russian language as an interstate intermediary language in Central Asia, as well as Russia’s reaction to these processes. Central Asia now show an increasing number of students learning other foreign languages such as Chinese, English and Turkish. As a result authors are forecasting the increase of external players influence. In addition, are analyzing political and social effects that are expected to arise as a result of the diminishing role of the Russian language in the region, including future occurrence of Russian-speakers’ enclaves and an outflow of the Russian-speaking population from these countries.

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Северо-западный регион ЮАР до недавнего времени не являлся промышленно марганценосным. Однако результаты изучения последних лет дают основание думать, что здесь могут быть залежи марганцевых руд. Марганцевое оруденение в этом регионе встречается в виде марганцевых конкреций, порошкообразного марганцевого вада и марганцевых корок в коре выветривания. Марганцевые конкреции приурочены к аллювиальной части «Westwits alluvium» рудного разреза и марганцевый вад накоплялся в карстовых структурах, образовавшихся в результате приповерхностного выветривания, выщелачивания и растворения подстилающих марганценосных неоархейских доломитов. Предполагается два потенциальных источника марганца: первый расположен непосредственно под рудным телом, а второй – на существенном удалении от него. Если первый источник рудного вещества поставлял марганец из подстилающих доломитов в процессе их выветривания, то второй вариант подразумевает существенный перенос металла из неизвестных коренных источников, расположенных на значительном удалении от области рудонакопления. Таким образом, для решения этого вопроса, необходимо провести экспериментальные исследования, изучающие природу, минералогию и источник сноса терригенных отложений «вмещающих материалов» верхнего рудного разреза. Цель работы – уточнить природу марганценосных терригенных залежей «Westwits alluvium» и, что самое важное, определить их коренной источник поступления и собственно минеральный состав. Методики исследования включали: петрографическое описание пород, геохимические анализы методами XRF и SEM, подсчеты объемного состава детритовых минералов и анализ дискриминационных диаграмм. Результаты. В результате проведенных исследований было установлено, что терригенные зёрна в основном представлены кварцем. Содержание полевых шпатов, минералов цемента и глинистых минералов не более 20 %. Использована классификация составов терригенного материала, основанная на подсчете в объемных процентах зерен кварца, полевого шпата, обломочных зерен других пород (вулканических, магматических и метаморфических пород), слюды и др. По этим данным были определены вероятные источники сноса, которыми являются породы Рэнд-Антиклинального хребта, расположенного к югу от изучаемого региона, а также архейские граниты, гнейсы и мафические-ультрамафические породы Каапваальского кратона. Осадконакопление происходило в низменной равнине с тропическим умеренно влажным и субгумидным климатом. Здесь, при повышенном рН воды происходило интенсивное выщелачивание пород и замещение детритовых зерен разного минерального состава диоксидом марганца. Ключевые слова: марганцовистый аллювий, третичный, терригенные отложения, Каапваальский кратон, Южная Африка The North-West region of the Republic of South Africa was previously not considered to constitute of manganese mineralization of industrial value. However, recently published articles indicated the presence of secondary manganese mineralization in the weathering crust, underlain by the manganiferous Neoarchean dolomites. Manganese mineralization in this region occurs in the form of manganese nodules, powdered manganese wad, and manganese crusts. Manganese nodules are confined to the alluvial part of the ore section known as the «Westwits alluvium» and manganese wad is accumulated in karstic structures formed as a result of near-surface weathering, leaching, and dissolution of underlying manganese-bearing Neoarchean dolomites. Two potential sources of manganese are assumed: the first relates to the dolomites which are located directly under the ore body, and the second relates to the source areas of terrigenous deposits. If the first hypothesis suggests that manganese ore substances were supplied from the underlying dolomites during their weathering, the second option then implies a significant transfer of metal from unknown root sources located at a considerable distance from the area of ore accumulation. Thus, it is necessary to conduct petrographic study to reconstruct their source regions and understand the close relations with Mn mineralization. Aim is to clarify the nature of the manganese-bearing terrigenous deposits «Westwits alluvium» and, most importantly, to determine their root source of supply and the actual mineral composition. Methodology of study includes mainly: petrographic study of rocks, geochemical analyses with the use of XRF and SEM methods, modal compositional analysis of the detrital minerals, and analysis of discrimination diagrams. Results. As a result of the conducted research, it was found that terrigenous grains consist mainly of detrital quartz grains. The content of feldspars, cement minerals and clay minerals seldom exceeds 20 %. The classification of terrigenous material based on the calculation of the volumetric percentage of the detrital framework grains: quartz, feldspar, clastic grains of other rocks types (volcanic, igneous and metamorphic rocks), mica, indicated probable source areas of the terrigenous sediments. These include metasedimentary rocks of the Rand Anticline Ridge which is located south of the studied region, and Archean granites, gneisses, and mafic-ultramafic rocks of the Kaapvaal Craton. In the basin of deposition, sedimentation occurred in a lowland plain within tropical region, characterized by moderately humid and sub-humid climatic conditions. These conditions, combined with oxidation and increased pH of the basin waters, contributed to the replacement of detrital grains with manganese dioxide

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The Northwest manganese ore mineralisation is located at a relative distance from traditionally known manganese mining areas in a new manganese-bearing region (Highveld) in the Northwest Province, Republic of South Africa. The ore occurrence was studied on farms: Buchansvale 61 IQ, Weltevreden 517 JQ, Rhenosterhoek 343 JP and Kafferskraal 306 JP. The data obtained from studying the geology of the area pointed out to interests regarding the development criterias for search of similar ore mineralisations in the northwest region of South Africa. The ore occurs predominantly in the form of powdered manganese wad, manganese nodules and crusts, confined to the karstic structures of the upper section of the dolomites. X-ray powder diffraction (XRD), Scanning electron microscopy with energy dispersive link (SEM-EDS) and X-ray fluorescence were utilized to unveil the mineral and chemical composition of the ore samples. The present study therefore presents the results on both chemical and mineral composition of manganese ores, and their depth and longitudinal distribution. Karstic areas causing an increased local thickness of the ore body were identified. The geochemical and microspcopic study of the ores indicates their supergene nature. The main ore minerals includes cryptomelane, lithiophorite, purolusite, hollandite and romanechite associated with impurity components of Ba, Ce, Co, La, Cr, Zn and V.

The geological structure, structural relations with the underlying complexes, mineral composition, age and origin of sedimentary-volcanogenic and intrusive formations of the Chamberlain valley area (northern part of the Wedel Jarlsberg Land, Svalbard Archipelago) are considered. As a result of the studies, two stages of the Late Precambrian endogenous activity in this area have been identified. For the first time the Vendian ages (593-559 Ma) of intrusive (dolerites) and effusive (basalts, andesites, tuffs) rocks were determined by U-Pb-method (SHRIMP-II) for Svalbard Archipelago. At the same time, the Grenville ages for large bodies of gabbro-diorites, metadolerites bodies (1152-967 Ma), and metagranites (936 Ma) were determined for the first time for this area, which correlates well with the ages of magmatic formations obtained earlier in the southern part of Wedel Jarlsberg Land. A detailed petrographic and petrochemical characterization of all the described objects were compiled and the paleotectonic conditions of their formation were reconstructed. Based on these data, the Chemberlendalen series, which is dated to the Late Vendian, and the Rechurchbreen series, which the authors attribute to the Middle Riphean and correlate with the lower part of the Nordbucht series are distinguished. The data obtained indicate a two-stage Precambrian magmatism in this area of the Svalbard archipelago and, most importantly, provide evidence for the first time ever of endogenous activity on Svalbard in the Vendian time. This fact makes it possible to reconsider in the future the history of the formation of folded basement of the Svalbard archipelago and the nature of the geodynamic conditions in which it was formed.