CHAPTER XIII 



EARTH FEATURES SHAPED BY RUNNING WATER 



The newly incised upland and its sharp salients. The suc- 

 cessive stages of incising, sculpturing, and finally of reducing an 

 uplifted land area, are each of them possessed of distinctive 

 characters which are all to be read either from the map or in the 

 lines of the landscape. Upon the newly uplifted plain the incis- 

 ing by the young rivers is to be found chiefly in the neighbor- 

 hood of the margins. In this stage the valleys are described as 

 V-shaped canons, for the valley wall meets the upland surface 

 in sharp salients (plate 12 A), and the lines of the landscape are 

 throughout made up from straight elements. Though the land- 

 scapes of this stage present the grandest scenery that is known 

 and may be cut out in massive proportions, often with rushing 

 river or placid lake to enhance the effect of crag and gorge, they 

 lack the softness and grace of 

 outline which belong only to the 

 maturer erosion stages. The 

 grand canon of the Colorado 

 presents the features character- 

 istic of this stage in the grandest 

 and most sublime of all exam- 

 ples, and the castled Rhine is a 

 gorge of rugged beauty, carved 

 out from the newly elevated 

 plateau of western Prussia, 

 through which the water swirls in eddying rapids (Fig. 175). 



The stage of adolescence. As the upland becomes more 

 largely invaded as a consequence of the headward advance of 

 the canons and their sending out of tributary side canons, the 

 sharp angles in which the canon walls intersect the plain become 

 gradually replaced by well-rounded shoulders. Thus the lines in 

 the landscape of this stage are a combination of the straight 



169 



FIG. 175. Gorge of the River Rhine 

 near St. Goars, incised within an up- 

 lifted plain which forms the bill tops. 



