HOW MANY COAL SEAMS ARE PRESENT IN ILLINOIS?
There are at least 40 different coal seams in Illinois, but most are relatively thin. Seven coal seams have been mined extensively, and all together 20 or more have been mined.
Figure 10—Some root, stem, and leaf fossils found in Illinois coal-bearing rocks.
Neuropteris ⅖× Nosopteris stem ⅔× Neuropteris ½× Lepidodendron ⅖× Pecopteris ⅔× Stigmaria ⅖× Annularia ⅔× Spiropteris ⅔× Sphenophyllum 1×