Early crust of the Podolia Domain of the Ukrainian Shield: Isotopic age of terrigenous zircons from quartzites of the Bug Group
| Autor: | Stefan Claesson, E. V. Bibikova, A. A. Fedotova, L M Stepanyuk |
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| Rok vydání: | 2015 |
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| Zdroj: | Stratigraphy and Geological Correlation. 23:555-567 |
| ISSN: | 1555-6263 0869-5938 |
| Popis: | Detrital zircons of the ancient metasedimentary rocks bear important information about the early crust of the Earth. In this work, the early crust in the west of the Ukrainian Shield was studied using U-Pb dating of terrigenous zircons from metasedimentary rocks (quartzites) of the lower parts of the Bug Group (Kosharo-Aleksandrovka Formation) of the Podolia Domain and through Sm-Nd isotopic investigation of these rocks. The Nd model age of rocks is 3.4–3.1 Ga. Detrital zircons were studied in two samples of quartzites. The cathodoluminescent images of most zircons support their clastic origin. More than 150 zircon grains were studied on an ion microprobe. The isotope age of zircons is 3775–2000 Ma. These results were compared with previous results of study of terrigenous zircons from garnet schists of the Zaval’e quarry located closely to the studied area. It is concluded that both Paleoarchean and Meso- to Neoarchean rocks were destroyed during formation of terrigenous rocks of the Bug Group. The different amount of ancient zircons in quartzites and garnet schists indicates the different remoteness of the most ancient rocks from sedimentary basins. |
| Databáze: | OpenAIRE |
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