| details |
Early Oligocene |
|
USSR(Kazakh SSR) |
Bronevoy,V.A. et al. Correlation of Oligocene deposits of different facies in Western Kazakhstan. (In: Geology and Useful Fossils from the Turgai Basin) |
1971 |
| details |
Eocene |
Early Oligocene |
USSR |
Aristova,K.E. Pollen and microplankton from the Eocene-Oligocene boundary deposits in the Southern Part of the USSR |
1973 |
| details |
Late Eocene |
Oligocene |
USSR(Kazakh SSR) |
Zhezhel,O.N. The boundary between Eocene and Oligocene deposits at North Ustyurt (according to palynological data). (In: Palynology, Method and Stratigraphy) |
1973 |