Petrological-geochemical features of ore-bearing effusive and intrusive rocks of the Nikolaevskoe gold-porphyry deposit (the Southern Urals)

Object. The article considers the results of geochemical studies of ore-bearing effusive and intrusive rocks of the Nikolaevka gold deposit, located in the zone of the Main Uralian fault in the Southern Urals. The deposit belongs to the gold-porphyry type which unconventional for the Urals and poorly studied here. Methods. The rock composition was determined by chemical analysis (IG UFRC RAS), mass-spectrometry with inductively coupled plasma on the ELAH 9000 quadrupole mass-spectrometer (IGG UB RAS) and X-ray fluorescence analysis on the VRA 30 spectrometer (IG UFRC RAS). Results. It is established that gold-porphyry mineralization associated with an island-arc volcanic-intrusive complex that unites plagiophyric and pyroxene-plagiophyric basalts, their tuffs, gabbro intrusions and ore-bearing series of dikes plagiophyric dolerite-porphyrites and gabbro-diorite-porphyrites. The rocks of the complex, including ore-bearing dikes, have normal alkalinity, tholeitic and transition from tholeitic to calc-alkaline composition. Among the volcanogenic formations, faunistically dated in the zone of the Main Ural fault in the Southern Urals, by a number of geochemical parameters (for example, the ratios of Zr/Nb and Nb/Th) the effusive and intrusive rocks of the deposit are the closest to the volcanics of the pyrite-bearing Baymak-Buribay Formation (D1e2), lying at the base of the section of the Magnitogorsk island arc, and, in all probability, are their age analog. At the same time, the gold-bearing complex differs from the Baymak-Buribay Formation by a general increased iron and titanium content, with a reduced magnesia of all rock types, as well as the absence of boninites and acid volcanics, the predominance of porphyry rock types, which can be due to the geodynamic conditions of its formation. Conclusion. Geodynamic analysis of geochemical data using diagrams (La/Sm)N-TiO2 and V-Ti/1000 suggests that the Nikolaevka deposit was formed in the articulation zone of the island arc and the back-arc basin. Gold-porphyry mineralization associated with the Late Emsian volcanic processes was isolated in the Southern Urals for the first time

Волновые процессы в дрейфующем льду Cеверного Ледовитого океана в экспедиции MOSAiC. Зимний период

One of the main directions of theoretical and applied research in the Arctic is the study of physical and mechanical processes in the atmosphere — ice — ocean system. For this purpose, theoretical and experimental problems are solved. The paper employs the method of monitoring the state of drifting ice by means of autonomous seismic stations in the MOSAiC international expedition in 2019–2020. The method of remote registration of ice information with a discreteness of 100 Hz made it possible to obtain data on the processes of compression and crushing of ice of various temporal and spatial scales. The paper presents early findings on the development of physico-mechanical processes in the ice cover under the influence of wind, oceanic gravitational waves, compression and crushing phenomena during large-scale deformations in drifting ice. The amplitude-frequency spectra of surface gravitational waves obtained in this work provide sufficient reason for attributing the phenomena described to swell waves and infra-gravity waves that occur in the stormy areas of the oceans. New data have been obtained on low-frequency horizontally polarized waves caused by the compression of ice and movements along breaks in the cohesive ice cover. The article considers the possibilities of using instrumental monitoring of the occurrence and development of tidal compression and crushing in the drifting ice of the Arctic Ocean. The results obtained can be used to develop methods for predicting the state of ice in real time both in engineering tasks and for improving weather and climate forecasting models.Одной из основных научных и прикладных проблем в Арктике являются исследования физико-механических процессов в системе атмосфера — лед — океан. С этой целью решаются теоретические и экспериментальные задачи. В настоящей работе использовался метод мониторинга состояния дрейфующего льда с помощью автономных сейсмических станций в международной экспедиции MOSAiC в 2019–2020 гг. Метод дистанционной регистрации ледовой информации с дискретностью100 Гц позволил получить данные о процессах сжатия и торошения льдов различного временного и пространственного масштаба. В работе представлены первые результаты о развитии физико-механических процессов в ледяном покрове при воздействии ветра, океанических гравитационных волн, явлениях сжатия и торошения при крупномасштабных деформациях в дрейфующем льду. Полученные в работе амплитудно-частотные спектры поверхностных гравитационных волн являются основанием относить описанные явления к волнам зыби и инфрагравитационным волнам, возникающим в штормовых районах океанов. Получены новые данные о низкочастотных горизонтально-поляризованных волнах, обусловленных сжатием льдов и подвижками по разрывам в сплоченном ледяном покрове. Рассмотрены возможности использования инструментального мониторинга возникновения и развития приливного сжатия и торошения в дрейфующих льдах Северного Ледовитого океана. Полученные результаты могут быть использованы для разработки методов прогнозирования состояния льдов в режиме реального времени как в инженерных задачах, так и для совершенствования моделей прогноза погоды и климата

Current status of nuclear cardiology in the Russian Federation

The article is devoted to the analysis of the current status of nuclear cardiology in the Russian Federation. The data on the number of facilities performing radionuclide investigations for the diagnosis and monitoring of the treatment of cardiovascular diseases, their staffing and equipment are given. The statistics of the conducted nuclear cardiology tests for 2018-2020 are given, as well as their methods, features and diagnostic significance are described