DEGEADATIOK . 107 







Having found that degradation is accelerated by increased declivity at 

 a high rate, let us apply this law to the degradation of the Uinta uplift and 

 see what topographic features would have been produced if the uplift had 

 been abrupt or greatly faster than degradation. As the area was uplifted 

 in large part as an integer, its steep flanks would then have been regions of 

 great declivity, while its axial region would have comparatively gentle slopes, 

 and as the first streams heading along the axis ran toward the flanks, these 

 streams would not only have had channels suddenly increasing in declivity 

 at the flanks, but the amount of water carried by the streams would have 

 steadily increased from axis to flanks, and hence corrasion on the flanks 

 would have proceeded at a rate determined by these multiplied causes. As 

 the main channels were thus corraded all the lateral channels would in like 

 manner have been rapidly corraded ; this would have induced rapid sapping 

 and rapid erosion, and the degradation along the flanks would have far 

 exceeded degradation along the axis, and this would have resulted in the 

 production of an ever narrowing axial ridge. An examination of the map 

 reveals the fact that these are not the topographic characteristics of the 

 Uinta Mountains. The axial region is higher in the western portion of that 

 part of the range under consideration, but the difference in elevation 

 between the flanks and axis is inconsiderable when compared with the whole 

 amount of degradation; while in the eastern portion of the part of the range 

 under consideration the axial region is much lower than the flanking region 

 on either side. Here the excess of degradation in the axial region is 

 accounted for by remembering that the degradation of consequent drainage 

 has been assisted by the degradation resulting from extra limital or through 

 drainage. But in the former case, i. e., the western portion of the region 

 under consideration, the drainage is all consequent on the upheaval, and to 

 account for the plateau like character of the region, we have to suppose 

 either that the elevation being constant has been but little faster than 

 degradation , or else that elevation has been intermittent. 



O ' 



Let us further consider these two hypotheses, one of which must be 

 true. If elevation was constant but slow, the axial region was first attacked 

 by degradation, and as it was slowly uplifted, degradation kept this axial 



