Basalts of the riphean sequence of the Bashkir meganticlinorium (southern Ural): new 147Sm-143Nd and Rb-Sr ID-TIMS isotopic constrains
- Authors: Puchkov V.N.1, Ronkin Y.L.1, Sergeeva N.D.2
-
Affiliations:
- Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences
- Institute of Geology, Ufa Federal Research Center of the Russian Academy of Sciences
- Issue: Vol 518, No 1 (2024)
- Pages: 85-96
- Section: PETROLOGY
- Submitted: 31.01.2025
- Published: 29.11.2024
- URL: https://edgccjournal.org/2686-7397/article/view/649927
- DOI: https://doi.org/10.31857/S2686739724090098
- ID: 649927
Cite item
Abstract
The first results of 147Sm-143Nd and Rb-Sr ID-TIMS isotope-geochronological comparative study of twelve samples of volcanic rocks of the Bashkir meganticlinorium are presented, for which U-Pb SHRIMP-II dating was previously carried out using zircons extracted from these samples, which revealed the dominance of Paleozoic ages among three event-stratigraphic levels in the Riphean of the Southern Urals. New 147Sm-143Nd and Rb-Sr ID-TIMS isotope data showed that the evolution of volcanics occurred as a result of crust-mantle interaction. In the Taratash anticlinorium, Nd model ages (TDM) of 2302–2540 Ma) of volcanics are regarded as the ages of the protolith, characterized by εNd(t) values: from –17.4 to –20.5. In the Yamantau anticlinorium, the TDM value (2033 Ma) of Paleozoic volcanics indicates a younger (Paleoproterozoic) substrate. Minimum Nd model ages (TDM = 1160–1233 Ma) were determined for Paleozoic volcanics spatially associated with metabasalts of the Igonino magmatic event (707–732 Ma) in the Tirlyanskaya syncline. The lowest values of εNd(t) (–3.2, –0.9, –0.7), indicating a decrease in the proportion of the crustal component relative to the mantle material, were obtained in Paleozoic metabasalts in the Tirlyanskaya syncline on the eastern wing of the Bashkir meganticlinorium, which may be due to activation of plume processes in the East of the folded mountain structure. Thus, Rb–Sr and 147Sm-143Nd ID-TIMS isotope systematics of the studied volcanics make it possible to expand the understanding of mantle-crustal phenomena within three event-stratigraphic levels of the Riphean of the Southern Urals.
About the authors
V. N. Puchkov
Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences
Email: y-ronkin@mail.ru
Corresponding member of the RAS
Russian Federation, EkaterinburgYu. L. Ronkin
Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences
Author for correspondence.
Email: y-ronkin@mail.ru
Russian Federation, Ekaterinburg
N. D. Sergeeva
Institute of Geology, Ufa Federal Research Center of the Russian Academy of Sciences
Email: y-ronkin@mail.ru
Russian Federation, Ufa
References
- Пучков В. Н., Козлов В. И., Краснобаев А. А. Палеозойские U-Pb SHRIMP-датировки магматических пород Башкирского мегантиклинория // Геологический вестник. 2011. № 9. Юбилейный выпуск. Институт геологии УНЦ РАН. Уфа: ДизайнПолиграфСервис. С. 36–43.
- Краснобаев А. А., Пучков В. Н., Сергеева Н. Д., Бушарина С. В. Полихронные цирконы вулканитов Навышского комплекса айской свиты нижнего рифея (Южный Урал) // Георесурсы. 2020. Т. 22. № 4. С. 101–112 https://doi.org/10.18599/grs.2020.4.101-112
- Краснобаев А. А., Пучков В. Н., Сергеева Н. Д., Бушарина С. В. Природа цирконовой кластики в песчаниках рифея и венда Южного Урала // Георесурсы. 2019. Т. 21. № 1. С. 15–25. https://doi.org/10.18599/grs.2019.1.15-25
- Ludwig K. R. User's manual for Isoplot 3.6: a geochronological toolkit for Microsoft. Excel. 2008. № 4. 77 p.
- Puchkov V. N., Krasnobaev A. A., Sergeeva N. D. The New Data on Stratigraphy of the Riphean Stratotype in the Southern Urals, Russia // Journal of Geoscience and Environment Protection. 2014. № 2. P. 108–116
- Стратиграфический кодекс России. СПб.: Издательство ВСЕГЕИ, 2019. 96 с. (МСК России, ВСЕГЕИ)
- Ronkin Y. L., Karaseva T. V., Maslov A. V. The First 147Sm–143Nd Data on Rocks from the 6925.2- to 8250-m Interval of the SG-7 Superdeep Borehole (West Siberian Oil-and-Gas Province) // Dokl. Earth Sc. 2021. 496. 130–134. https://doi.org/10.1134/S1028334X2102015X
- Петрографический кодекс России. Магматические, метаморфические, метасоматические, импактные образования. Изд. 2. СПб.: Изд-во ВСЕГЕИ, 2008. 200 с.
- DePaolo D. J. Neodymium Isotope Geochemistry. An Introduction. Minerals and Rocks Series. 1988. № 20. xi + 187 pp.
- Ронкин Ю. Л., Хойман К. Определение погрешностей Sm-Nd модельных датировок // Труды Института геологии и геохимии им. акад. А.Н. Заварицкого. 2009. Выпуск 156 (Ежегодник 2008). Екатеринбург. С. 334–336.
- Papanastassiou D. A., Wasserburg G. J. Initial strontium isotopic abundances and the resolution of small time differences in the formation of planetary objects // Earth Planet. Sci. Let. 1969. 5: 361–376.
- Краснобаев А. А., Бибикова Е. В., Ронкин Ю. Л., Козлов В. И. Геохронология вулканитов айской свиты и изотопный возраст нижней границы рифея // Известия АН СССР, серия геологическая. 1992. № 6. С. 25–40.
- Магматические горные породы (кислые и средние породы). Отв. ред. В.В. Ярмолюк, В.И. Коваленко. М.: Наука, 373 с.
- Краснобаев А. А., Бибикова Е. В., Степанов А. И., Кирнозова Т. И., Ронкин Ю. Л., Макаров В. А., Лепихина О. П., Кравцов А. В. Возраст эффузивов машакской свиты и проблема изотопно-геохронологической границы нижний-средний рифей / В книге: Изотопное датирование процессов вулканизма и осадкообразования. М.: “Наука”, 1985. С. 162–175.
- Arndt N. T., Goldstein S. L. Use and abuse of crust-formation ages // Geology. 1987. 15. P. 893–895.
- Puchkov V. N., Ernst R. E., Ivanov K. S. The importance and difficulties of identifying mantle plumes in orogenic belts: An example based on the fragmented large igneous province (LIP) record in the Ural fold belt // Precambrian Research. 2021. 361. 106–186. https://doi.org/10.1016/j.precamres.2021.106186
- Ronkin Yu. L., Sindern S., Maslov A. V., Matukov D. I., Kramm U., Lepikhina O. P. Oldest (3.5 Ga) zircons of the Urals: U-Pb (SHRIMP-II) and T DM constraints // Doklady Earth Sciences. 2007. 415(6). 860‒865 https://doi.org/10.1134/S1028334X07060074
- Ронкин Ю. Л., Синдерн С., Лепихина О. П. Изотопная геология древнейших образований Южного Урала // Литосфера. 2012. № 5. С. 50–76.
- Dickin A. P. Model Ages (Sm-Nd). Encyclopedia of Scientific Dating Methods. 2014. 1–7. https://doi.org/10.1007/978-94-007-6326-5_2-2
- McNutt R. H., Dickin A. P. A comparison of Nd model ages and U-Pb zircon ages of Grenville granitoids: constraints on the evolution of the Laurentian margin from 1.5 to 1.0 Ga // Terra Nova. 2012. 24. 7–15.
Supplementary files
