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Geolocation
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Author - title
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Year
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| details | Middle Pennsylvanian | Iowa | Ravn,R.L. Palynostratigraphy of the Lower and Middle Pennsylvanian Coals of Iowa | 1986 | |
| details | Middle Pennsylvanian | Late Pennsylvanian | Illinois | Ravn,R.L. Palynostratigraphy of the Lower and Middle Pennsylvanian Coals of Iowa | 1986 |