Age and Geodynamic Conditions of Formation for the Neoproterozoic Gold-Bearing Granitoids in the Eastern Sayan
| Autor: | A. G. Mironov, Sergey Zhmodik, B. B. Damdinov, L. B. Damdinova, A. V. Travin, V. B. Khubanov |
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| Rok vydání: | 2020 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Archean Geochemistry Geology Genetic relationship Massif 010502 geochemistry & geophysics Ophiolite 01 natural sciences Tectonics Magmatism Island arc Structural geology 0105 earth and related environmental sciences |
| Zdroj: | Geotectonics. 54:356-365 |
| ISSN: | 1556-1976 0016-8521 |
| Popis: | The paper discusses the results of petrogeochemical and geochronological studies of the Tainsky granitoid stock containing the Tainsky gold deposit in the East Sayan. The Tainsky granitoid stock intrudes through ultrabasites of the Ospa-Kitoi ultrabasitic massif. Granitoids are the part of the ophiolite cover which overlap Archean basement rocks of the Tuva-Mongolian microcontinent of the Archean foundation. Consistent isotopic age values in the range of 850–860 Ma obtained by three independent methods (U–Pb, Re–Os, 40Ar/39Ar) are evidence of the Neoproterozoic age of granitoid magmatism and its genetic relationship with gold–(±copper)–porphyry mineralization. The geological setting, geochemical characteristics, and age of the Tainsky granitoid stock allow us to attribute these rocks to the Neoproterozoic Dunzhugur island arc sequences. Isotopic age values obtained by Rb–Sr and 40Ar/39Ar methods characterized by lower closure temperatures of isotopic systems make it possible to distinguish several tectonothermal events at 650, 435, 339–333, and 280–223 Ma, reflecting difference stages of tectonic evolution of the Eastern Sayan segment of the Central Asian folding belt. |
| Databáze: | OpenAIRE |
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