EROSIONAL HISTORY OF DRIFTLESS AREA 107 



on the east side of the Mississippi river in Wisconsin and 

 Illinois, where the area has never been glaciated and where 

 there is no other known cause for exceptionally crooked 

 streams, Trenipeleau, Black, Kickapoo, Grant, Platte, Little 

 Platte, Pecatonica, Galena, and Apple rivers all have dis- 

 tinctly crooked courses where the area has never been 

 glaciated and where there is no other known cause for ex- 

 ceptionally crooked streams (Fig. 33). Kummel' studied 



Fig. 33. A map showing a portion 

 of the course of Galena river near 

 Benton. \\'!SCDnsin. The curves may 

 constitute intrenched meanders. 

 (After Martin). 



the Galena, Platte, Grant, and Pecatonica rivers, described 

 their meandering courses and their mature valleys, and 

 concluded that they could not have been developed in a 

 single cycle, either by superposition or by inequalities in 

 resistance of rock. He concluded that they are true in- 

 trenched meanders significant of more than one cycle of 

 erosion. His argument is convincing but hardly conclusive. 

 There are so many ways in which curves might be developed 

 and so diflicult is it to distinguish curves made in differ- 



1. Kummel. H. B.. "Some meandering rivers of Wisconsin." Science, New Series, 

 Vol. I (189.5). pp. 714-716. 



