Abstract
We present the first comprehensive data for the early Ediacaran stage of evolution of the western active continental margin of the Siberian Craton (Yenisei Ridge). U-Pb (SHRIMP-II SIMS) data for zircons from dikes of picrodolerites, quartz diorites, and leucocratic granites show that they were emplaced at 625 ± 5, 623 ± 8, and 626 ± 5 Ma, respectively, which indicates a narrow time window of Ediacaran magmatic events. The mafic tholeiitic rocks have OIB and E-MORB mantle components in their magmatic sources. Mineralogical and geochemical observations showed that the mantle-sourced mafic melts assimilated some crustal material, forming Th-enriched dikes of intermediate composition and K-and Rb-enriched felsic rocks. The possible geodynamic conditions for the formation of these early Ediacaran dikes are shown and a geodynamic model is presented for the development of the Yenisei Ridge orogen from the late Cryogenian to the late Ediacaran.
Original language | English |
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Article number | 565 |
Pages (from-to) | 1-23 |
Number of pages | 23 |
Journal | Minerals |
Volume | 10 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1 Jun 2020 |
Keywords
- Continental margin
- Dikes
- Ediacaran
- Magmatism
- Siberian Craton
- U-Pb and Ar-Ar geochronology
- Yenisei Ridge