Comparison of the Domanic Outcrops in the Volga-Ural and Timan-Pechora Basins

Resumo

Domanic (and domanicoid) deposits are of great interest to researchers and oil producing companies, since they possess authigenic oil and gas contents. This work presents the results of studying the domanic outcrops in the Volga-Ural and Timan-Pechora basins. The stratigraphic interval included sediments from the Middle Frasnian stage of the Upper Devonian to the Tournaisian stage of the Lower Carboniferous. The main types of rocks are characterized by microscopic examinations of thin sections and geochemical parameters of organic matter are determined. It is shown that the domanic deposits of the Timan-Pechora basin are similar in structure and lithological composition to the domanic deposits of the Volga-Ural Basin. The upper part of the domanicoid section is distinguished by the domination of carbonate-siliceous types of rocks over kerogen mixed varieties. According to the geochemical parameters, the organic matter in the rocks from the domanic deposits of the Volga-Ural and Timan-Pechora basins belongs to type II; however, the organic matter of the high-carbon sequence is more mature in the outcrops of the Volga-Ural region than in the Timan-Pechora outcrops.