New Early Frasnian stratas on the Middle Timan (Tsil’ma River basin)

Research subject. Rocks and paleontological fossils (spores of higher plants) of early Frasnian sedimentation within the Tsil’ma area (Middle Timan). Material and methods. The lithological and biostratigraphical methods were used to identify and describe lithological stratons, determine the composition of spore complexes of higher plants characteristic of each straton in the early Frasnian outcrops of the Tsil’ma area, as well as to correlate the latter with the zonal patterns of the Devonian of the East European Platform. Results. In the Middle Timan, within the Tsil’ma area, new stratons were described in various structural and facies zones, i.e., the Brusnichnaya, Rudyanskaya, and Paladinskaya formations, characterizing the early Frasnian period of sedimentation. The identified stratons have distinct lithological and palynological characteristics. A description of limitotypes and composite stratotypes was carried out. Conclusions. At present, the Brusnichnaya, Rudyanskaya, and Paladinskaya formations are the most complete sequence of early Frasnian sedimentation in the European North-East of Russia. Here, regional responses to the global events of Frasnes (soluta conodont zone) and Genundewa (rugosa conodont zone) are recorded. The formations are characterized by spore complexes; palynozones are correlated with conodont zones. This allowed correlation between the continental and marine early Frasnian deposits in the European North-East of Russia, along with establishment of their exact position in the Devonian stratigraphic scheme.

Middle Timan, Upper Devonian, Brusnichnaya, Rudyanskaya, Paladinskaya formations