References

gtcrust

Геодинамика и тектонофизика

Geodynamics & Tectonophysics

2078-502X

Institute of the Earth's crust of the Russian Academy of Sciences, Siberian Branch

10.5800/GT-2022-13-5-0671

gtcrust-1582

Research Article

ПАЛЕОГЕОДИНАМИКА

PALEOGEODYNAMICS

ПИТАЮЩИЕ ПРОВИНЦИИ ДЛЯ НИЖНЕПАЛЕОЗОЙСКИХ ПЕСЧАНИКОВ НОРА-СУХОТИНСКОГО ТЕРРЕЙНА: РЕЗУЛЬТАТЫ U-Th-Pb И Lu-Hf ИЗОТОПНЫХ ИССЛЕДОВАНИЙ ДЕТРИТОВЫХ ЦИРКОНОВ

SOURCES OF LOWER PALEOZOIC SANDSTONES FROM THE NORA-SUKHOTINO TERRANE: RESULTS OF U-Th-Pb AND Lu-Hf ISOTOPE STUDIES OF THE DETRITAL ZIRCONS

Смирнов

Ю. В.

Smirnov

Y. V.

675000, Благовещенск, пер. Релочный, 1

1 Relochniy ln, Blagoveshchensk 675000

Институт геологии и природопользования ДВО РАНРоссияInstitute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of SciencesRussian Federation

2022

10122022

135671671

2022

Смирнов Ю.В.

Smirnov Y.V.

Данная работа распространяется под лицензией Creative Commons Attribution 4.0.

This work is licensed under a Creative Commons Attribution 4.0 License.

https://www.gt-crust.ru/jour/article/view/1582

В публикации приведены результаты комплексных геологических, геохимических исследований песчаников бассейна р. Белой приамурского фрагмента Нора-Сухотинского террейна северо-восточного фланга Южно-Монгольско-Хинганского орогенного пояса, а также изотопных (U-Th-Pb и Lu-Hf) исследований детритовых цирконов из них. Установлено, что песчаники бассейна р. Белой характеризуются значительными вариациями состава обломочного материала и основных породообразующих компонентов, соответствуя аркозам и литаренитам. Их накопление происходило за счет размыва «зрелых» в геохимическом отношении магматических пород преимущественно кислого и среднего состава. В исследованных песчаниках преобладают цирконы ордовикского, кембрийского и неопротерозойского возраста. Возраст наиболее молодой популяции цирконов из песчаника бассейна р. Белой 451±8 млн лет, в связи с чем нижняя возрастная граница накопления приходится на поздний ордовик. Источниками ордовикских цирконов с положительными величинами εHf(t) и раннепалеозойскими – неопротерозойскими значениями Hf-модельного возраста, по-видимому, являлись островодужные комплексы соответствующего возраста. Источниками кембрийских и неопротерозойских цирконов с положительными величинами εHf(t) и нео- и мезопротерозойскими значениями Hf-модельного возраста, вероятно, являлись раннепалеозойские и неопротерозойские магматические образования Буреинского или Мамынского террейна. Имеющиеся геологические материалы позволяют рассматривать песчаники бассейна р. Белой в качестве фрагмента раннепалеозойского аккреционного комплекса, сформированного в раннем палеозое вдоль юго-восточной окраины Мамынского массива. Однако более определенным выводам мешает слабая изученность раннепалеозойского и неопротерозойского магматизма рассматриваемого региона.

This paper presents the results of comprehensive geological and geochemical studies of sandstones from the Belaya basin of the Amur fragment of the Nora-Sukhotino terrane of the northeastern flank of South Mongolia-Khingan orogenic belt, as well as the results of isotopic (U-Th-Pb and Lu-Hf) studies of detrital zircons therefrom. The sandstones from the Belaya basin are characterized by significant variations in the composition of clastic material and major rock-forming elements, and by correspondence to arkoses and litharenites. They were accumulated due to erosion of geochemically mature felsic and intermediate igneous rocks. The sandstones are dominated by Ordovician, Cambrian, and Neoproterozoic zircons. The youngest zircons in sandstones from the Belaya basin are dated back to 451±8 Ma, with the lower age boundary set at the Late Ordovician. The Ordovician zircons, which have positive εHf(t) values and Early Paleozoic – Neoproterozoic Hf-model ages, could have been derived from island arc complexes. The Cambrian and Neoproterozoic zircon grains with positive εHf(t) values and Neo – Mesoproterozoic Hf-model ages could have been derived from Early Paleozoic and Neoproterozoic igneous rocks of the Bureya or Mamyn terranes. The available geological materials provide evidence that the sandstones from the Belaya basin are a fragment of the Early Paleozoic accretionary complex, which formed in the Early Paleozoic along the southeastern margin of the Mamyn (Xing’an) massif. However, a small amount of data on the Early Paleozoic and Neoproterozoic magmatism of the region hinders drawing more definite conclusions.

Нора-Сухотинский террейнранний палеозойпесчаникигеохимиядетритовые цирконы

Nora-Sukhotino terraneEarly Paleozoicsandstonesgeochemistrydetrital zircons

Исследования выполнены за счет гранта Российского научного фонда № 21-77-10001, https://rscf.ru/project/21-77-10001/.

The studies were done under the support of RSF grant 21-77-10001, https://rscf.ru/en/project/21-77-10001/.

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The authors declare that there are no conflicts of interest present.