| details |
Middle Eocene |
|
Colorado |
Bradley,W.H. Origin and microfossils of the oil shales of the Green River Formation of Colorado and Utah. |
1931 |
| details |
Middle Eocene |
|
Utah |
Bradley,W.H. Origin and microfossils of the oil shales of the Green River Formation of Colorado and Utah. |
1931 |
| original |
Eocene |
|
W.Germany(Hesse) |
Potonie,R. The microbotany of the Eocene Brown Coal of the Geiseltal. |
1934 |
| details |
Late Oligocene |
Miocene |
Germany(Brandenburg) |
Thiergart,F. Pollen flora of Brown Coal from the Niederlausitz, especially from the Marga Mine near Senftenberg |
1938 |
| details |
Ypresian |
|
Belgium |
Pastiels,A. Contribution to the study of microfossils of the Belgian Eocene. |
1948 |