On the Relative Age of the Late Cretaceous Zorin and Chingandzha Floras in the Northeast of Russia

Abstract

The Zorin and Chingandzha floras significantly differ in their systematic composition, but they are buried at the same stratigraphic level. On this basis, they are considered to be of the same age and are assigned to the Turonian–Coniacian period. The revealed features of the lithological composition of the plant-bearing deposits, their sequence, and the composition of the overlaying volcanic rocks indicate that both floras represent the first stage of the development of the outer zone of the Okhotsk–Chukotka Volcanic Belt. However, they are separated by one or two local geological events, and hence by a significant period of time. It can be confirmed that the Zorin flora was formed and existed earlier than the Chingandzha flora.