U-Pb Dating of the Kolchugino Group Basement (Kuznetsk Coal Basin, Siberia): Was the Change in Early–Middle Permian Floras Simultaneous at Different Latitudes in Angaraland?
Vladimir V. Silantiev,
Yaroslav M. Gutak,
Marion Tichomirowa,
Alexandra Käßner,
Ruslan V. Kutygin,
Lyubov G. Porokhovnichenko,
Eugeny V. Karasev,
Anastasia S. Felker,
Aleksandr S. Bakaev,
Maria A. Naumcheva,
Milyausha N. Urazaeva,
Veronika V. Zharinova
Affiliations
Vladimir V. Silantiev
Department of Palaeontology and Stratigraphy, Institute of Geology and Petroleum Technology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia
Yaroslav M. Gutak
Institute of Mining and Geosystems, Siberian State Industrial University, 654007 Novokuznetsk, Russia
Marion Tichomirowa
Institute of Mineralogy, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
Alexandra Käßner
Institute of Mineralogy, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
Ruslan V. Kutygin
Laboratory of Stratigraphy and Palaeontology, Diamond and Precious Metal Geology Institute, Siberian Branch Russian Academy of Sciences, 677891 Yakutsk, Russia
Lyubov G. Porokhovnichenko
Siberian Paleontological Scientific Centre, Geology and Geography Faculty, Tomsk State University, 634050 Tomsk, Russia
Eugeny V. Karasev
Borrisiak Palaeontological Institute, Russian Academy of Sciences, 117647 Moscow, Russia
Anastasia S. Felker
Borrisiak Palaeontological Institute, Russian Academy of Sciences, 117647 Moscow, Russia
Aleksandr S. Bakaev
Borrisiak Palaeontological Institute, Russian Academy of Sciences, 117647 Moscow, Russia
Maria A. Naumcheva
Borrisiak Palaeontological Institute, Russian Academy of Sciences, 117647 Moscow, Russia
Milyausha N. Urazaeva
Department of Palaeontology and Stratigraphy, Institute of Geology and Petroleum Technology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia
Veronika V. Zharinova
Department of Palaeontology and Stratigraphy, Institute of Geology and Petroleum Technology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia
The Kuznetsk Basin (Kuzbass) is one of the largest coal basins in Siberia and a reference area for the ancient Angaraland continent. The proximity of the Kuzbass and Siberian Platform caused their biotic similarities in the Late Palaeozoic. However, due to biota endemism, the Kuzbass Upper Palaeozoic does not correlate directly with the International Chronostratigraphic Chart (ICC). This paper discusses radioisotopic (CA-ID-TIMS) dating of zircons from a volcanic tuff located in the Starokuznetsk Formation (Fm). This level matches the interval of the Balakhonka/Kolchugino (B/K) floral change in Kuzbass, i.e., the gradual replacement of cordaitoid-dominated wet forests (Balakhonka flora) with more arid fern–pteridosperm–cordaitoid assemblages (Kolchugino flora). New age (276.9 ± 0.4 Ma) directly correlates the Starokuznetsk Fm with the Upper Kungurian of the ICC. We compared the Kuzbass data with data of the Western Verkhoyanie, where Middle Permian ammonoids (Sverdrupites assemblage) occur in strata recording the B/K floral change. The available (ICC) and new datings indicate the lag between the B/K floral change in low (Kuzbass) and high (Verkhoyanie) latitudes of Angaraland. The B/K floral change in the Kuzbass began in the early Late Kungurian and was completed by the end of this age. In contrast, the B/K floral change in Verkhoyanie began at the end of the Late Kungurian and was completed in the Late Wordian. The delay in the floral changes at different latitudes of Angaraland suggests that existing interregional correlations need further improvement.
