231 



Glaciai. History of Bean Blossom Creek. 



As has been previously stated Bean Blossom Creek was laked by the 

 ice-sheet which crossed its lower course. At the time of its laking there 

 were deposited in its vallej* the deltas together witli the loose materials 

 that now cover the benches on either side.* 



Post-Glacial History of Bean Blossom Creek. 



Since glacial time Bean Blossom has been a diminutive, meandering 

 creelv in a bi'oad, fiat-tloored valley, and throughout all postglacial time it 

 has persisted in keeping to the south or west side of its valley. Evidently 

 it does not fit its present valley. This fact suggests that the creek has not 

 been able, on account of its diminutive size and the lack of time, to do 

 much constructive work since tlie ice retreated. It is now at grade for 

 ten miles above its moutli and must be actually aggrading its channel. 



We quote Prof. ^Marstcrs for a more detailed description of this 

 topic.** 



•'Since tlie close of tlie laking stage Bean Blossom River has developed 

 a meandering course on its broad floor. Only in the narrowest sections 

 of the valley lias it succeeded in spreading its meander belt across the 

 entire tioor. For the most part it keeps to the west or south side of the 

 valley, and yet still assumes a meandering habit for considerable 

 stretches. In other words, the stream does not fit the present dimensions 

 of the broad valley, which, accordingly, must have Ijeen brought al)out ))y 

 otlier conditions tlian that resulting from lateral cutting, by a mature 

 stream. Cross sections of the valley at its broadest places reveal a slight 

 curvature of surface in the center and occasional abandoned meandering 

 channels. This slight variation from a plain surface suggests flood plain 

 construction. Whether this constructive work antedates the glacial 

 episode of Bean Blossom is not certain, but it would seem from the d;ita 

 at hand, that the present postglacial Bean Blossom has not l>ad tinu' or 

 the ability to do much constructive Avork since pleistocene time." 



Two more things of interest in connection with Beau Blossom Creek 

 remain to be explained. They are: (1) The reason for the channel of the 

 creek keeping to its south l)ank. and (2) the reason why the slopes on the 

 south side of the valley are steeper than those on the north. 



*'See Marsters. loe. eit. for further Jiseussion of this subject. 

 '•"'■■•Loe. eit. p. 236. 



