Departmental Papers (EES)

Document Type

Book Chapter

Date of this Version

January 1970


Abundant data from spore studies of the Colchester (no. 2) Coal Member and from investigations of plant compressions in the Francis Creek Shale provide an opportunity to compare the flora of the coal with that of the overlying shale in the northeastern part of the Illinois Basin. As both floras were investigated by different methods and since different systems of form genera were used, it is first necessary to review the plant taxa found in the 2 facies and to arrange them according to major plant groups. Paleoenvironmental interpretations of Pennsylvanian floras are rare and widely scattered in the literature; therefore some of the research on fossil spores and plant assemblages from other strata is discussed in this report. Finally, the report presents an interpretation of paleoecological conditions that existed during deposition of peat and mud, which eventually formed the No. 2 Coal and Francis Creek Shale.


This material has been published in Smith, W.H., Nance, R.B., Hopkins, Johnson, R.G., and Shabica, C.W. Depositional environments in parts of the Carbondale formation, western and northern Illinois: Francis Creek Shale and associated strata and Mazon Creek biota, Illinois State Geological Survey Field Guidebook Series, No. 8, p. 61-74, 1970

NOTE: At the time of publication, author Hermann W. Pfefferkorn was affiliated with the Illinois State Geological Survey. Currently (September 2005) he is a faculty member in the Department of Earth and Environmental Science at the University of Pennsylvania.



Date Posted: 15 September 2005