DEVELOPMENT OF PALEOBOTANY IN THE ILLINOIS BASIN 45 



dealt with the use of spores in the differentiation of coals in the Alleghenian Ser- 

 ies and the second was concerned with coals in the Pottsvillian Series (Guennel, 

 1952, 1958). Guennel (1954) also discussed the megaspore species Triletes tri- 

 angularis, which is found in abundance in one of the Block Coal Members of Indi- 

 ana. The paleobotany, including spores, and chemical composition of the Indiana 

 paper coal and its depositional environment have been studied by Neavel and 

 Guennel (1960). The Indiana coal also provided material for a study of the origin 

 and function of the thickened portion of the exine of Torispora and the relation of 

 this genus to the sporangium Bioolaria (Guennel and Neavel, 19 61) . The deposi- 

 tional environment of the Colchester Coal (Ilia) of Indiana was interpreted by Neavel 

 (in Zangerl and Richardson, 1963) from his petrographic analyses and from Guen- 

 nel' s spore analyses of various intervals through the coal. After Guennel went to 

 Marathon Oil Company, H. W. Lee took over palynological studies at the Indiana 

 Survey for a short time. He published a paper on a coal maceration method in 

 1964. 



University Studies 



Gray and Taylor (19 67a) described and illustrated some morphological var- 

 iations in Ahrensisporites symetrious from a coal in the Mansfield Formation in 

 Putnam County, Indiana. The same authors (1967b) compared the spore assem- 

 blages from the Schultztown Coal of western Kentucky with that of the Colchester 

 (No. 2) Coal of Illinois. Lewis R. Gray, who received his doctorate at the Uni- 

 versity of Illinois and is now at the Amundsen-Mayfair Branch of Chicago City 

 College, was Kosanke's last graduate student at Illinois. Taylor's interest in paly- 

 nology developed early, and he and Eggert at Chicago Circle embarked on the light 

 and electron microscopy study of the spores and pollen from coal-ball fructifica- 

 tions (Taylor, 1968, 1970; Taylor and Eggert, 1969a; and Taylor and Millay, 1969). 



The scanning electron microscope is a new, significant tool for microfos- 

 sil studies, and it has permitted the resolution and effective illustration of mor- 

 phological differences in spores of quite similar coal-ball plants from different 

 stratigraphic positions (Phillips and Rosso, 1970). Spores and pollen from iden- 

 tifiable fructifications and attached foliage or axes can be identified with isolated 

 spores from coal and other sedimentary rocks to provide a basis for establishing 

 natural affinities of isolated spores, their variation within a single sporangium, 

 and various stages of maturation, as was done by Hall and Stidd (1971). 



Contribution of Coal Petrography to Paleobotany 



Coal petrography is the description and classification of the components 

 of coal, and its study in the Illinois Basin began in the 1920s. The emphasis of 

 early research in coal petrography was directed toward discovering the paleobo- 

 tanical composition of coal to find clues to how coal was formed. To achieve this 

 goal, both chemical (maceration) and physical methods (thin sections, polished 

 sections) were developed for studying the organic components of coal. However, 

 the paleobotanical information contributed by petrographic studies is rather limited 

 in comparison with the detailed information to be obtained from palynology and the 

 study of coal balls. Only in rare cases can techniques of petrographic study be 

 used to classify plant specimens. 



