THE DRIFTLESS REGION OF WISCONSIN 8 I 



does receive their impact (and has certainly for a long time) is 

 indistinguishable from the rest of the weathered surface. But 

 the results of torrential abrasion are so different from those 

 described that it need not be seriously considered as a possible 

 agent. 



If this be a case of glacial abrasion, and it is difficult to 

 resist such a conclusion, it must necessarily decide the question 

 as to the existence of small local glaciers, since its situation is 

 such that if glaciated at all it was certainly the work of such 

 local glaciers. 



It was my hope during the season just passed to make a 

 series of observations at critical points with a view to a more 

 definite determination of certain doubtful features, but owing to 

 a pressure of other work they were for the most part left incom- 

 plete. On two points, however, evidence of considerable value 

 was obtained. The first relates to the frontal characteristics of 

 the bowlder beds, especially the frontal slope. This appears to 

 have been normally steep as compared with the portion imme- 

 diately back of it along the axis of a valley. 



This characteristic is shown in two or three of the beds 

 which fail to reach the present river level, but as they fall within 

 the limits of the highest terrace it is open to question whether 

 the effect was not due to erosion when the river was at that 

 stage. But I have ascertained that the same characteristic is 

 found in beds which terminate a hundred feet or more above 

 this level. Still another bed extends to the present river level 

 and has been truncated by river erosion, but gives no indication 

 of erosion at the higher level, although by situation it was 

 especially exposed to erosive action — far more so than the 

 other beds which were well protected from currents. 



The second relates to the disposition of the beds along the 

 sides of the valleys showing that on reaching their rocky sides 

 the beds rise to higher level than along the axes of the valleys, 

 This is not hillside wash since the material is foreign to the hills 

 on the sides of which it occurs. 



Assuming these beds to be glacial an interesting question is 



