Belaya River Section of Maikop deposits is the closest to the Maikop town, typical for Western and Central Ciscaucasus, well outcropped and studied and should be considered as a type section for the Maikop Group. Here it is possible to observe a continuous transition from the underlying light marls of Belaya Glina Formation to the dark clays of Pshekha Formation at the base of the Maikop succession. Pshekha Fm is characterized by nannoplankton NP21 and NP22 zones, dinocysts Phthanoperidinium amoenum (D13) and Wetzeliella symmetrica zones, mollusk association with Pterolucina batalpashinica at the bottom and rich fish fauna. The succession shows a normal polarity chron C13n for the base of the Pshekha and revers polarity C12r above.
Marl of Polbian Bed with brackish Lower Solenovian mollusks, ostracod association with Disopontocipris oligocaenica, nannoplankton of NP23 Zone and dinocysts of Wetzeliella gohtii Zone lies above with erosion contact. Overlying Lower Morozkina Balka Subformation contains from non-calcareous clays and concludes the remains of fish and dinocysts of Wetzeliella gohtii Zone. The Upper Morozkina Balka Subformation contains calcareous sublayers with nannoplankton NP23 Zone in lower part and NP24 one above, dinocysts Chiropteridium partispinatum Zone, Rhombodinium draco Subzone. Polarity pattern we interpret to correspond to C10n, C9r and C9n.
Batalpashinsk Formation corresponds to the time of maximum hydrogen sulfide contamination of the Late Oligocene basin and is dated by nannoplankton NP25 Zone, and dinocysts Chiropteridium patrispinatum Zone with Rhombodinium draco Subzone in lower part and Deflandrea spinulosa (non typica) Subzone in the middle and upper parts. Septarian+Zelenchuk Fm is composed of clays with septarian concretions, and interbedded sands with the same dinocysts and foraminifera with Spiroplectammina aff. terekensis. Calcareous interlayers in the top of the formation conclude nannoplankton of NP25-NN1 Zone. Karadzhalga Formation is composed mainly “fish lithofacies” and includes dinocysts zone Labyrinthodinium truncatum (Lower Miocene) in basal part.
Lectostratotype of maikopian group – Belaya River section upstream of Maikop town (Western Ciscaucasia) in the Oligocene part
