52 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 480 



Grliger recently worked on Pleistocene palynology in Illinois (Griiger, 1970, 

 1972), with the assistance of the Illinois Geological Survey. He investigated 

 three cores from lake sediments that had been deposited during the Illinoian glaci- 

 ation. Five zones can be recognized, and they show the change to warm intergla- 

 cial climate, the influence of the Wisconsinan glaciation, and fluctuations in 

 post-glacial times. In a more detailed study, Griiger (19 72) interpreted, from pol- 

 len analysis of sediment at 11 different localities, the vegetational changes that 

 took place in Illinois during Wisconsinan time. 



SUMMARY 



Paleobotanical studies in the Illinois Basin began with the establishment 

 of state geological surveys, and their early directors, such as David Dale Owen 

 and A. H. Worthen, encouraged such work. The development of universities and 

 museums in the area further expanded and diversified the fossil plant studies from 

 the Devonian, Mississippian, Pennsylvanian, Cretaceous, and Pleistocene sedi- 

 mentary deposits. 



Among the pioneers of paleobotany in the Illinois Basin, Leo Lesquereux, 

 David White, and A. C. Noe'made particularly influential contributions. 



The economic importance of coal deposits of Pennsylvanian age stimulated 

 the first studies of compressions-impressions, coal petrography, coal balls, and 

 palynology. Stratigraphic studies also have stimulated paleobotany by providing 

 a framework for much paleobotanical research, and the resultant data have aided 

 stratigraphy. Paleobotanical studies of the Pennsylvanian in particular have had 

 a major impact on all branches of paleobotany. 



Palynology has been effectively used in correlation of the Pennsylvanian 

 coals and for interpretation of the Pleistocene climate. 



The growth of paleobotany has accelerated in recent years. Two-thirdsof 

 the publications on paleobotany have been written since 1950, and, while most of 

 the paleobotanists who developed the new branches of fossil plant studies are still 

 active, many new workers have entered paleobotany. Its expansion to increasing 

 numbers of universities and other institutions is indicative of further growth. 



Acknowledgmen ts 



The following contributors generously furnished us with information and 

 permitted us to quote from their letters: Henry N. Andrews, Chester A. Arnold, 

 Harriette V. Krick Bartoo, Robert W. Baxter, James E. Canright, Joan M. Culver, 

 William C. Darrah, John W. Hall, Raymond E. Janssen, Robert M. Kosanke, J. E. 

 Lamar, Gilbert A. Leisman, Lawrence C. Matten, Fredda D. Reed, James M. 

 Schopf, and Wilson N. Stewart. 



Heinz Damberger, Illinois Geological Survey, helped us work with the sec- 

 tion on coal petrography. Schopf and Kosanke also read parts of the manuscript 

 and made valuable suggestions. Mrs. Penelope Laughnan, Botany Department, 

 University of Illinois, helped compile the bibliography. 



We are most grateful for their assistance. 



