Late Ordovician Volcanism of the Northern Part of Altai–Sayan Area and Its Geodynamic Nature
- Authors: Vorontsov A.A.1,2, Perfilova O.Y.3, Kruk N.N.4,5, Tarasyuk A.S.1
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Affiliations:
- Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences
- Irkutsk State University
- Siberian Federal University
- Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences
- Novosibirsk State University
- Issue: Vol 485, No 2 (2019)
- Pages: 347-354
- Section: Geology
- URL: https://journals.rcsi.science/1028-334X/article/view/194765
- DOI: https://doi.org/10.1134/S1028334X19040093
- ID: 194765
Cite item
Abstract
The results of geological–geochemical studies of some Late Ordovician associations in the frame of the Minusinsk Trough with available geological and U–Pb, Rb–Sr, and K–Ar age dates are presented. The Late Ordovician volcanic rocks form a continuous igneous series, the basalts of which are different from Devonian basalts of the Minusinsk Trough in the lower TiO2 content (≥ 1.7 wt %) and more fractionated REE pattern. These features should be considered the index characteristics of Late Ordovician rocks. Their compositions reflect processes of fractionation crystallization and mixing of trachibasaltic magmas with crustal melts. When taking into account the regional geological data, it is shown that magmatic activity at the Late Ordovician endogenic evolution stage in the northern part of the Altai–Sayan fold area was caused by the interaction of a mantle plume and the lithospheric mantle, which was metasomatically reworked and enriched in water during former subduction processes.
About the authors
A. A. Vorontsov
Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences; Irkutsk State University
Author for correspondence.
Email: voront@igc.irk.ru
Russian Federation, Irkutsk, 664033; Irkutsk, 664033
O. Yu. Perfilova
Siberian Federal University
Email: voront@igc.irk.ru
Russian Federation, Krasnoyarsk, 660041
N. N. Kruk
Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences; Novosibirsk State University
Email: voront@igc.irk.ru
Russian Federation, Novosibirsk,
630090; Novosibirsk, 630090
A. S. Tarasyuk
Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences
Email: voront@igc.irk.ru
Russian Federation, Irkutsk, 664033