Correlation levels in upper famennian - tournaisian deposits of the north of Urals and Сhernyshev swell

The Upper Devonian - Lower Carboniferous stratigraphic interval of the North of Urals and Urals Foredeep is promising for search of hydrocarbons and other mineral deposits. So urgent is the establishment of a detailed stratigraphic framework and the identification of levels with the high correlation potential. Conodont biostratigraphic boundaries (expansa, praesulcata, sulcata, duplicata, sandbergi, quadruplicata, and isosticha zones) and global events (Dasberg, Hangenberg, and Lower Alum Shale) in the Upper Famennian - Tournaisian of the North Urals and Chernyshev Swell (Kozhim River section, Syvyu River section, Izyael River section and Malaya Usa River section) are characterized. As a result the levels having the highest correlation potential (base of the sulcata Zone, base of the quadruplicata Zone, transgressive phases of the Hangenberg Event and Lower Alum Shale Event) are identified. Detailed studies of the distribution of conodonts in the Devonian-Carboniferous boundary interval revealed that taxa Polygnathus purus Voges and Pseudopolygnathus primus Branson et Mehl begin its spread on the level of the first appearance of Siphonodella sulcata (Huddle). Consequently, they are on a par with Siphonodella sulcata (Huddle) can determine the position of the boundary between the systems in the sections of the North Urals and Chernyshev Swell.