| original |
Early Ypresian |
|
Virginia |
Frederiksen,N.O. Paleogene sporomorph biostratigraphy, Northeastern Virginia. |
1979 |
| details |
Early Ypresian |
Middle Ypresian |
Virginia |
Gibson,T.G. et al. Biostratigraphy of the Tertiary strata of the core. |
1980 |
| details |
Ypresian |
|
Virginia |
Frederiksen,N.O. Lower Tertiary pollen biostratigraphy Maryland and Virginia. (In: Cretaceous and Tertiary Stratigraphy, Paleontology and Structure, Southwestern Maryland and Northeastern Virginia. N.O.Frederiksen and K.Krafft, editors) |
1984 |
| details |
Middle Miocene |
|
Massachusetts |
Frederiksen,N.O. Stratigraphic, paleoclimatic and paleobiogeographic significance of Tertiary sporomorphs from Massachusetts |
1984 |
| details |
Late Sabinian |
Claiborne |
USA(Gulf Coast) |
Frederiksen,N.O. Sporomorph biostratigraphy, floral changes, and paleoclimatology, Eocene and Earliest Oligocene of the eastern Gulf Coast. |
1988 |
| details |
Ypresian |
|
Virginia |
Frederiksen,N.O. Rates of floral turnover and diversity change in the fossil record. |
1991 |