Аннотация:Devonian deposits are well-known in the Earth stratigraphy as one of the main levels of organic matter (OM)
enrichment in rocks. Terrigenous complex of D1-D3fr1-2 is widely distributed within the East European platform
and is observed as one of the main source rock formations for hydrocarbon (HC) generation within the northern
and eastern part of the platform, including the giant Romashka field. However, many researchers believe that
about 90% of hydrocarbons have been generated by Domanik deposits dated by Middle Frasnian, Upper
Devonian (Semiluk or Domanik horizon)
Typical Domanik formation which name became denominative for all rocks enriched in sapropelic and humicsapropelic
OM and strongly bitumen-contaminated in the oil window zone are characterizing the sediments of
depression facies. They are being usually formed in marine basins in the conditions of long uncompensated
subsidence with low sedimentation rates (2-5 m/mln. years). Main rock-forming components for Domanik
formation are carbonates, silica, terrestrial component and OM in various quantities. Domanik formation of the
East-European platform is characterized by prevailing of carbonates if compared to Jurassic analogues of
Western Siberia – Bazhenov formation representing clayey-siliceous mineral composition. Typical Domanik is
widely spread within the eastern part of the East European platform. Its lithological analogues are observed in
Upper Frasnian - Lower Carboniferous sequence including Tournaisian and even lower part of Visean. These
sediments are emphasized in the volume of “domanikoid formation” (Mkrtchan, 1977; Formation…, 1990). Their
origination is dated to the axis zones of Kama-Kinel troughs, the rocks are also enriched in OM of the same type
although TOC concentrations decrease towards the trough shoulders.