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Information × Registration Number 0218U002240, 0112U006803 , R & D reports Title Chronostratigraphy and geodynamic conditions for the formation of sedimentary-volcanogenic rocks of greenstone belts of the eastern part of the Ukrainian shield popup.stage_title Head Artemenko Gennady Vladimirovich, Registration Date 06-02-2018 Organization nstitute of Geochemistry, Mineralogy and Ore Formation popup.description2 Object of research - metavolcanites and metasedimentary rocks of greenstone structures, TTG, intrusive rocks. The purpose of the work - is to characterize of the geodynamic conditions for the formation of sedimentary and volcanogenic complexes of rocks of greenstone structures of the Middle-Dnieper and Azov megablock on the basis of chronostratigraphic, petrological and isotope-geochemical data, to develop a spatial and temporal model for the formation of greenstone belts of the eastern part of the Ukrainian Shield. Methods of investigation - ion-ion microprobe (SHRIMP), LA-ICP-MS and classical uranium-lead methods for dating zircon and monazite. The content of small and rare elements in rocks was determined by the ICP-MS method. Silicate analyzes were carried out using wet chemistry methods in the laboratory of the IGMP of the National Academy of Sciences of Ukraine. It was established, that mesoarhean granite and greenstone associations of the Middle-Dnieper and Azov megablocks formed as a result of the rise of the mantle plume ~ 3,17 - 3,0 Ga on the consolidated basement, which included the Mesoarchean Dnieper-Sumy (3,2 Ga) and the Eoarchaean-Paleoarchaean (3,3-3,8 Ga) Azov-Oskol blocks. The Dniester-Bug block of the Eoarchaean age (3,8 Ga) was beyond the influence of this plume. The main part of the plume is traced, probably, with greenstone structures containing peridotite comatiites in the Middle-Dnieper megablock and the West Azov block, while the greenstone structures of the Eastern Azov - Pavlovka and Zeleniy Gay, in which there are no komatiites, were formed, probably, on the peripheral part of the plume. The zonal heterogeneity in the composition of the Archean volcanic complexes of greenstone structures and granitoids of the Middle-Dnieper and Azov megablock and its relation with the age of the basement was determined. In the West Azov block with the Paleoarchaean basement, volcanism in the greenstone structures was bimodal, and in the greenstone structures of the Middle-Dnieper megablock with a mesoarchean foundation, the polymodal one. The lower age limit of formation of the Belozerska series is established - 3,0 Ga. Early TTG magmatism (3,1-3,0 Ga) manifested itself synchronously on both blocks. Later TTGs (2.92-2.83 Ga) were formed only on the West Azov block, while on the Middle-Dnieper - these phases correspond to the potassium-sodium crust granites. This is probably due to the depletion of the mantle under the older core of the West Azov block and the deeper levels of magma generation. Product Description popup.authors Артеменко Геннадій Володимирович Вільковський Валерій Олександрович Гоголєв Константин Ігорович Гурненко Алла Іванівна Демедюк Валентина Валентинівна Самборська Ірина Анатоліївна Стеценко Марина Євграфівна Швайка Ірина Анатоліївна popup.nrat_date 2020-04-02 Close