Инд. авторы:	Ivanov A.V., Letnikova E.F., Schkolnik S.I., Prochenkin A.I., Brodnikova E.A.
Заглавие:	Age of rocks of the Shurmak Formation according to U-Pb dating of zircon by LA-ICP-MS method (south-eastern Tuva)
Библ. ссылка:	Ivanov A.V., Letnikova E.F., Schkolnik S.I., Prochenkin A.I., Brodnikova E.A. Age of rocks of the Shurmak Formation according to U-Pb dating of zircon by LA-ICP-MS method (south-eastern Tuva) // Вестник Санкт-Петербургского университета. Науки о Земле. - 2020. - Vol.65. - Iss. 4. - ISSN 2541-9668. - EISSN 2587-585X.
Идентиф-ры:	DOI: 10.21638/spbu07.2020.406; WoS: 000595437000009;
Реферат:	eng: At the south-eastern part of Tuva, early Proterozoic volcanogenic-sedimentary deposits have been studied including conglomerates from Shurmak formation. As the result of U-Pb zircon dating from tuff with andesitic composition, conglomerate matrix and volcanicomictic sandstones from this formation, it has been established that it was accumulated at around 500 Ma. The dating results for zircons from tuff are a geochronological date and indicate the time of manifestation of andesitic volcanism synchronous with accumulation of Shurmak Formation deposits. Given the close age of zircons of the main populations in both tuff and clastic rocks, one can assume that the formation of the latter is related directly to the manifestations of volcanism on this territory at this time. The presence in the tuff of xenogenic zircons and in volcanicomictic sandstones and matrix of Shurmak Formation of detrital zircons with Neoproterozoic and Paleoproterozoic age, as well as Sm-Nd isotopic data indicate that these volcanic and sedimentary processes in the early Cambrian time took place within the range if Precambrian block of earth's crust. The main supplier of clastic material during the formation of the Early Cambrian Shurmak Formation were volcanic events synchronous with sedimentation. Other sources of clastic material entering the sedimentation basin were Neoproterozoic granitoids and, less commonly, Paleoproterozoic and Neoarchean rocks. Combination with the underlying rocks of the Mugur Formation of the Erza metamorphic complex occurred as a result of tectonic processes in the post-Cambrian time, since the sedimentation of the Shurmak Formation deposits and the processes of granulite metamorphism in the rocks of the metamorphic complex occurred almost simultaneously
Ключевые слова:	SANGILEN; EVOLUTION; COMPLEXES; Cambrian; U-Pb dating; zircons; age; conglomerates; sedimentary-volcanogenic deposits; BLOCK;
Издано:	2020