First results of U-Pb dating of detrital zircons from basal horizons of Uralides (Polar Urals)

Uralides are represented with the complexes of two compositional types. The first one nearly completely consists of sedimentary units located mainly in the western Urals, in the Western Uralian Megazone. In contrast to this, in the eastern Urals (in the East Ura lian Megazone) Uralides are composed mainly of vol anogenic and volcanogenicsedimentary rocks. The distinctive elements of the West Uralian Megazone in the Polar Urals are two explicitly different subtypes of Paleozoic sedimentary sequences.