| original |
Early Oligocene |
Middle Oligocene |
USSR(Ukrainian SSR) |
Aristova,K.E. Pollen and microplankton in ancient Eocene and Oligocene deposits of the Bakhehisaraisk Region of Crimeria. (In: Palynology and Stratigraphy of the Paleozoic, Mesozoic and Paleogene of the European Part of the USSR and Central Asia) |
1971 |
| details |
Late Eocene |
|
USSR(Ukrainian SSR) |
Andreeva-Grigorovich,A.S. et al. Stratigraphic separation of the Kiev deposits in the Region of the Kiev Dnieper area according to microphytoplankton |
1975 |
| details |
Late Eocene |
Middle Oligocene |
USSR(Ukrainian SSR) |
Mikhelis,A.A. et al. The age and correlation of Naglinok of the Dniepr Territory near Kiev from palynological data |
1975 |
| details |
Late Eocene |
Early Oligocene |
USSR(Ukrainian SSR) |
Zosimovich,V.Y. et al. The boundary between Upper Eocene and Oligocene in the Kiev Dnieper area as based on palynological data. |
1979 |
| details |
Early Bartonian |
|
USSR(Kazakh SSR) |
Benyamovskii,V.N. et al. Paleogene Stage Scale of the Turgai Depression. |
1989 |
| details |
Early Oligocene |
Middle Oligocene |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |