| details |
Duckmantian |
|
Kentucky |
Greb,S.F. et al. An Insitu occurrence of coal balls in the Amburgy Coal Bed, Pikeville Formation (Duckmantian), Central Appalachian Basin, USA. |
1999 |
| details |
Westphalian A |
|
Virginia |
Eble,C.F. Lower and Lower Middle Pennsylvanian coal palynofloras, southwestern Virginia. |
1996 |
| details |
Late Westphalian A |
|
Kentucky |
Eble,C.F. et al. Palynologic, petrographic and geochemical characteristics of the Manchester Coal Bed in eastern Kentucky. |
1995 |
| original |
Middle Pennsylvanian |
|
Iowa |
Ravn,R.L. Palynostratigraphy of the Lower and Middle Pennsylvanian Coals of Iowa |
1986 |