| details |
Pennsylvanian |
Early Permian |
Pennsylvania |
Cross,A.T. et al. Representative microfossil floras of some Appalachian Coals |
1952 |
| details |
Desmoinesian |
|
Indiana |
Guennel,G.K. Fossil spores of the Alleghenian Coals in Indiana |
1952 |
| details |
Westphalian B |
Westphalian C |
W.Germany(N.Rhine) |
Kremp,G.O.W. On the importance of spores for determining the age of Paleozoic strata. |
1951 |
| details |
Nd |
|
Nd |
Cross,A.T. Plant microfossils and the application of their study to Coal stratigraphy. |
1950 |
| details |
Atokan |
Desmoinesian |
Illinois |
Kosanke,R.M. Plant microfossils in correlation of Coal Beds. |
1947 |
| details |
Desmoinesian |
|
Illinois |
Kosanke,R.M. Plant microfossils in correlation of Coal Beds. |
1947 |
| details |
Desmoinesian |
Virgilian |
Illinois |
Kosanke,R.M. Plant microfossils in correlation of Coal Beds. |
1947 |
| original |
Early Allegheny |
|
Iowa |
Schopf,J.M. et al. An annotated synopsis of Paleozoic fossil spores and the definition of generic groups. |
1944 |