EROSIONAL HISTORY OF DRIFTLESS AREA 19 



Associated Sets of Straight and Crooked Streams 



Although it seems impossible to distinguish intrenched 



meanders from other stream curves by a study of the curves 



themselves, comparison of a stream and its own tributaries 



will, in some cases at least, determine whether or not a 



Fig. 5. A plat of the course of White river taken from the Forsyth. Missouri top- 

 agraphic map. The stream flows in ;i young valley, and its course has been inter- 

 jireted to be a series of intrenched meanders. Reference to Fi.gxire 4 brings cut the 

 danger in such interpretations. So far as the curves themselves are concerned, 

 they might not be intrenched meanders, as that term is commonly applied, and the 

 surface might have suffered only one cycle of erosion. 



crooked stream is in its second cycle. When a stream is 

 old it meanders and has only a few tributaries which also 

 meander. After rejuvenation, many other tributaries are 

 developed, which do not meander. The early stages of a 

 second cycle then would exhibit two sets of streams, one of 

 v/hich includes only a few large, conspicuously crooked 

 streams, and the other set a large number of small, relative- 

 ly straight streams. If all the streams of a region were 

 formed in the same cycle under the same conditions, they 

 should all show the same general character and degree of 

 crookedness. If one set is curved and the other set straight, 

 both cannot have been developed in the same cycle. (Fig. 6) 

 It seems, therefore, that this association of one set of 

 streams which meander and a second set the members of 

 which are conspicuously more nearly straight affords 

 strong evidence that the surface on which the two sets are 

 thus associated is not in its first cycle of erosion. 



