Age limits of basal deposits of the Upper Cambrian section of the Polar Urals according to the results of U-PB (LA-ICP-MS) zircon dating

Based on the results of mass U–Pb (LA-ICP-MS) dating of detrital zircon from the basal deposits of the Upper Precambrian of the Polar Urals, represented by the Nyarovei series, their lower age limit was established. The upper age boundary of the basal series was obtained from the U–Pb (LA-ICP-MS) dating of zircon from the overlying volcanogenic formations of the Nemyurugan suite. Thus, it has been established that the deposits of the Nyarovey series were formed in a narrow time interval at the end of the Late Riphean about 750–650 million years ago in the Arshinian time. Identification of the series as a Middle Riphean straton is erroneous. The dominant role in the formation of the deposits of the Nyarovey series belonged to the products of erosion of nearby massifs of crystalline rocks, fragments of which are probably polymetamorphic complexes protruding in the Harbei-Marunkeu anticlinorium in the Polar Urals.