| details |
Late Pliocene |
Early Pleistocene |
Alaska |
Nelson,R,E. et al. Pollen analysis of a Late Pliocene and Early Pleistocene section from the Gubik Formation of Arctic Alaska. |
1985 |
| details |
Late Cenomanian |
|
Alaska |
Foster,H.L. et al. Fossil pollen from nonmarine sedimentary rocks of the eastern Yukon-Tanana Region, East-Central Alaska. (In: Geologic studies in Alaska by the U.S. Geological Survey,1989) |
1990 |
| details |
Early Pliocene |
Middle Pliocene |
Alaska |
Ager,T.A. et al. Pliocene terrace gravels of the ancestral Yukon River near Circle Alaska; Palynology, paleobotany, paleoenvironmental reconstruction and region correlation. (In: Tertiary Quaternary Boundaries. T.A. Ager et al, editors) |
1994 |
| details |
Middle Miocene |
Pleistocene |
Alaska |
White,J.M. et al. An 18 million year record of vegetation and climate change in northwestern Canada and Alaska: Tectonic and global climatic correlates. |
1997 |