AN INTERGLACIAL VALLEY IN ILLINOIS 



153 



convenience the time between the two glacial stages mentioned 

 may be called an interglacial epoch, remembering that in other 

 places it may be broken up into several stages of advance with 

 shorter inters^lacial stasfes. 



Fig. I. — Cartogram showing distribution of Early Wisconsin and Illinoian Drift 

 and the Shelbyville moraine and others, also the position of the Embarras River with 

 reference to these areas. Initial letters for towns and cities mentioned in text. Adapted 

 from Leverett, 111. Glac. Lobe. Monog. 38, U. S. G. S. 



Since the general slope of the state is from the north to the 

 south, most of the streams flow in that direction, and of those 

 taking their sources on the new drift several necessarily break 



