124 W. H. HOBBS REPEATING PATTERNS IN STRUCTURE OF LAND 



Page 



Sudden changes of throw on faults 171 



Evidence furnished by earthqualves 172 



Conclusion and request 175 



Eelief Patterns in Landscapes 

 character profiles 



To the physiographer who has critically surveyed the relief forms of 

 many districts with their manifold diversities in character of bedrock, in 

 structure, and in physiographic history, there is much which may be 

 read at the first glance. Perhaps first of all are noted those features of 

 the landscape which disclose the stage in the geographic cycle through 

 which the district is passing. There may be, further, distinguishing 

 lines which reveal in one case the work of waves, in another of mountain 

 glaciers or of a continental ice-sheet; again, it is a partial submergence 

 of the land which is disclosed, or a moulding of the surface under arid 

 conditions rather than the more familiar, if not more prevalent, denu- 

 dational processes of a humid climate. In the more striking instances — 

 with purer types — fault topography may be distinguished from fold 

 topography (see figures 1 and 2), though these are often merged in one 

 another. In Germany, at least, it is customary to differentiate table 

 mountains ("Tafelgebirge") and fold mountains ("Faltengebirge") with 

 their notably different relief characters. 



The broader relief characteristics which have been referred to, may 

 generally be read from the characteristic elemental lines that are usually 

 many times repeated in the landscape. Thus there may occur a nearly 

 horizontal line which is more or less abruptly continued downward in a 

 line of marked steepness and which indicates a youthful erosional stage 

 (a, of figure 3). Again it may be a gently flowing reversed curve — the 

 Hogarthian line of beauty — which is peculiar to mature landscapes (6, of 

 figure 3), or it may be that the upper portion of the Hogarthian line is 

 abruptly extended in a horizontal section, as would be the case when a 

 maturely eroded district has been depressed and partially submerged 

 (c, of figure 3). In those cases in which a shore has been successively 

 uplifted it is a long and gently sloping line which is abruptly joined to a 

 steep and often vertical one (d, of figure 3). The steplike profile of 

 table mountains differs from this in having a horizontal section combined 

 with a broken steeper portion (e, of figure 3), whereas fold mountains 

 are generally characterized by curving elements in an unsymmetiical 

 combination (/, of figure 3). Wherever volcanic cones appear, a beauti- 

 fully regular curve concave upward and resembling the sine curve will be 

 discovered (g, of figure 3). If mountain glaciers have occupied an up- 



