Vendian of the Middle Urals: A review of some investigations in the beginning of the 21st century

Abstract

Research subject. The research objects included a book section on the Vendian stratigraphy of the Yazvinsko-Kosva sub-zone of the Kvarkush-Kamenogorsk meganticlinorium, written for the Explanatory note to sheet O-40 – Perm of the State Geological Map 1000/3 of the Russian Federation, as well as the results obtained in the course of various thematic (stratigraphic, paleontological, litho- and isotope-geochemical, etc.) studies of the Vendian sedimentary sequences of the indicated territory.Materials and methods. The materials were facts, ideas and arguments in favor of certain conclusions and ideas of various authors. were analyzed. The methods included the comparison and analysis of facts, conclusions and ideas of predecessors.Results. It is suggested that the ideas about the architecture of the Vendian deposits of the western slope of the Middle Urals, dating back to the pioneering works of B.D. Ablizin and his colleagues, had almost reached perfection. At the same tim, the attribution of different formations to the regional stages of the Vendian of the East European Platform is still interpreted differently. Studies into the Vendian macrofauna on the western slope of the Middle Urals have also made significant progress in the first two decades of the 21st century, which, however, cannot be said about the studies of microfauna. The dating of detrital zircons from tillite-like conglomerates and sandstones of the Serebryanka and Sylvitsa groups should undoubtedly be continued. For the Vendian of the western slope of the Middle Urals, the dating of zircons from volcanic tuffs/ashes, as well as the search for correlations of already dated various igneous bodies with sedimentary sequences, is still relevant. This search is complicated by mountain taiga conditions. The prospects for studying the chemical composition of heavy fraction minerals, and reconstructing the composition and evolution of clastic sources for sedimentary sequences of the Serebryanka and Sylvitsa groups, seem almost boundless.Conclusions. The conducted analysis of works published in the first years of the 21st century on various aspects of the geo logy of the Vendian sedimentary sequences of the Middle Urals made it possible to identify their strengths and weaknesses and to outline directions for further research.

Assessment of Oil and Gas Potential in Vychegda Trough in Connection with the Identification of Potential Petroleum Systems

“…As noted in the literature [49], according to the paleotectonic reconstructions of the continents of Pre-Cambrian time, the Early Vendian stage of the East European Platform is associated with the global Lapland continental glaciation, explained by the location of the platform in the southern polar latitudes. The evidence for this is tillites and tillite-like (glacial) rocks in the Early Vendian sediments found in the peripheral areas of the East European Platform [50]. These areas were probably covered by a significant ice cover in the Late Riphean and Early Vendian age.…”