Age of rocks of the Shurmak Formation according to U-Pb dating of zircon by LA-ICP-MS method (south-eastern Tuva)
DOI:
https://doi.org/10.21638/spbu07.2020.406Abstract
In southeastern Tuva, early Proterozoic volcanogenic-sedimentary deposits were studied, including conglomerates from the Shurmak Formation. As a result of U-Pb zircon dating from tuff with andesitic composition, conglomerate matrix and volcanicomictic sandstones from this formation, it was established that it was accumulated at around 500 Ma. The dating results for zircons from tuff are a geochronological date indicating 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 the time. Zircons with Neoproterozoic and Paleoproterozoic ages are present in matrix of conglomerates and volcanicomictic sandstones of Shurmak Formation in the form of rock fragments and in tuffas in the form of xenogenic minerals. This, together with a result from Sm-Nd isotopic dating indicated that these vocanic and sedimentary processes in the early Cambrian time took place within the range of the Precembrian block of earfth’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.
Keywords:
sedimentary-volcanogenic deposits, conglomerates, age, zircons, U-Pb dating, Cambrian, Tuva
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Александров, Г. П. (1985). Геологическая карта СССР м-ба 1:200 000. Серия Западно-Саянская. Лист М-46-XVIII, XXIV. Объяснительная записка. Москва: Союзгеолфонд, 136.
Барабаш, Н. В., Владимиров, В. Г., Травин, А. В., Юдин, Д. С. (2007). 40Ar/39Ar датирование деформаций трансформно-сдвигового этапа эволюции ранних каледонид западного Сангилена (юго-восточная Тува). Доклады Академии наук, 414 (2), 226–232.
Ветров, Е. В., Уваров, А. Н., Вишневская, И. А., Червяковская, М. В., Ветрова, Н. И., Жимулев, Ф. И., Андреева, Е. С. (2020). Строение, возраст, геохимический и изотопно-геохимический (Sm/Nd) состав серлигской свиты Таннуольского террейна Тувы. Геология и минерально-сырьевые ресурсы Сибири, 41 (1), 81–94.
Иванов, А. В. (2018). Кембрийские отложения шурмакской свиты: состав и возраст пород питающих провинций. В: IX Сибирская конференция молодых ученых по наукам о Земле: материалы конференции. Новосибирск: ИПЦНГУ, 212–213.
Козаков, И. К., Натман, А., Сальникова, Е. Б., Ковач, В. П., Котов, А. Б., Подковыров, В. Н., Плоткина, Ю. В. (2005). Метатерригенные толщи Тувино-Монгольского массива: Возраст, источники, тектоническая позиция. Стратиграфия. Геологическая корреляция, 13 (1), 1–20.
Козаков, И. К., Азимов, П. Я. (2017). Геодинамическая обстановка формирования гранулитов Сангиленского блока Тувино-Монгольского террейна (Центрально-Азиатский складчатый пояс). Петрология, 25 (6), 635–645. https://doi.org/10.7868/S0869590317060048
Летникова, Е. Ф., Вишневская, И. А., Летников, Ф. А., Ветрова, Н. И., Школьник, С. И., Костицын, Ю. А., Караковский, Е. А., Резницкий, Л. З., Каныгина, Н. А. (2016). Осадочные комплексы чехла Дзабханского микроконтинента: различные бассейны седиментации и источники сноса. Доклады Академии наук, 470 (5), 570–574. https://doi.org/10.7868/S0869565216290223
Griffin, W. L., Powell, W. J., Pearson, N. J. and O’Reilly, S. Y. (2008). GLITTER: data reduction software for laser ablation ICP-MS. In: P. J. Sylvester, ed., Laser ablation ICP-MS in the Earth sciences: current practices and outstanding issues. Mineral. Assoc. Canada. Short Course, 40, 308–311.
Jackson, S. E., Pearson, N. J., Griffin, W. L. and Belousova, E. A. (2004). The application of laser ablation-inductively coupled plasma-mass spectrometry to in situ U-Pb zircon geochronology. Chemical Geology, 211, 47–69. https://doi.org/10.1016/j.chemgeo.2004.06.017
Ludwig, K. R. (2003). Isoplot 3.0. A geochronological toolkit for Microsoft Excel. Berkley Geochron. CenterSpec. Publ., 4.
Pfander, J. A., Jochum, K. P., Kozakov, I., Kroner, A. and Todt, W. (2002). Coupled evolution of back-arc and island arc — like mafic crust in the late Neoproterozoic Agardagh Tes-Chem ophiolite, Central Asia: evidence from trace element and Sr-Nd-Pb isotope data. Contrib. Mineral Petrol, 143, 154–174. https://doi.org/10.1007/s00410-001-0340-7
Rojas-Agramonte, Y., Kröner, A., Demoux, A., Xia, X., Wang, W., Donskaya, T., Liu, D. and Sun, M. (2011). Detrital and xenocrystic zircon ages from Neoproterozoic to Palaeozoic arc terranes of Mongolia: Significance for the origin of crustal fragments in the Central Asian Orogenic Belt. Gondwana Research, 19, 751–763. https://doi.org/10.1016/j.gr.2010.10.004
Van Achterbergh, E., Ryan, C. G., Jackson, S. E. and Griffin, W. L. (2001). La-ICP-MS in the Earth sciences — appendix 3, data reductions of tware for La-ICP-Ms. In: P. J. Sylvester, ed., Short course. St. John’s Mineral. Assoc., Canada, 29, 239–243.
Winchester, J. A. and Floyd, P. A. (1977) Geochemical Discrimination of Different Magma Series and Their Differentiation Product Using Immobile Elements. Chemical Geology, 20, 325–343. https://doi. org/10.1016/0009-2541(77)90057-2
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