Comparative characteristic of zircons of upper-proterozoic deposits, the Nyarovei series and the Nemuryugan suite (Polar Urals)

For the first time, a comparative analysis of zircons from metasedimentary, including carbon-containing Upper Proterozoic deposits of the Nyarovei series and the Nemuryugan suite of the Polar Urals was carried out. The study of the typical features of zircons showed differences in the internal structure and chemical composition of the mineral. For meta-sedimentary non-carbonaceous rocks, a flat surface and a homogeneous structure of zircon grains are characteristic. In zircons from carbon-containing deposits, the internal structure is inhomogeneous, there are secondary changes. In the Carboniferous deposits of the Nyarovei series and the Nemuryugan suite, uranium is found in zircon. Zircon originally could be enriched with uranium, or the formation of uranium in initially deformed zircons could be associated with hypergenic processes. In carbon-containing deposits of the Miniseyshor suite in zircons, in addition to uranium, yttrium, thorium and scandium are present.