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



plan of the earth's surface have been designated lineaments — significant 

 lines in the earth's face.^^ 



In part it is the composite expression of these lines and in part it is the 

 impertinent intrusion on the geologists' attention of the culture over- 

 printed on topographic maps which is responsible for a general failure to 

 take note of these significant character lines in the relief. Further, it is 

 to be emphasized that since the time of de Beaumont the attention of 

 geologists has been so largely withdrawn from the plan of the earth and 

 focused upon its buried and invisible structure that what may be called 

 orientational physiography is yet in its infancy. 



It can not be too strongly emphasized that the question of the exist- 

 ence of lineaments in the relief of any particular district is quite distinct 

 from that of the process or processes by which the topography along the 

 line in question may have been shaped. To illustrate, it has sometimes 

 been urged that a certain markedly rectilinear trench on the surface can 

 not have its origin in a fracture line of the crust for the reason that it 

 has been shaped by stream erosion, by a mountain glacier, or by some 

 other well recognized geological agent. ^^ It is, however, the control of 

 direction, not the details of sculpture, which is here of significance. To 

 quote an early worker in this field :^^ 



"Thus the great system of fractures which intersects the surface furnishes 

 the primary lines for the aspect of the surface of Norway. The mysterious 

 network of these lines is stamped in indelible characters ; it may indeed remain 

 a long time unnoticed, but if one has once seen it, it will never again escape 

 his observation. Like a moss-grown inscription upon a slab of marble, it is 

 there and to be deciphered. Here all embodied representations of plateaux, 

 inclined planes, and erosion of every sort, have not succeeded in hiding the in- 

 scription and withdrawing it from observation ; brush these once aside and the 

 eye can again clearly discern the runic characters, and it thus depends only 

 upon this that they all be correctly understood in the future." 



RELATION TO JOINTS AND FAULTS 



That lineaments are above rock fractures in the earth, their approxima- 

 tion to straight courses and their parallel arrangement testify. It does 

 not seem necessary to assume that they are in all cases above lines of 

 faulting, since drainage networks repeat in regular patterns where no 



20 W. H. Hobbs : The Uneaments of the Atlantic Border region. Bulletin of the Geo- 

 logical Society of America, vol. 15, 1904, pp. 483-506, pis. 45-47. Also Comptes Rendus 

 Congres Geogr. Inter,, 1906, pp. 193-203. 



21 Such a line of argument was made prominent in the discussion of two papers deal- 

 ing with the influence of structure planes in modifying the relief, which were read at the 

 International Congress of Geologists at Stockholm in August, 1910. 



23 KJerulf : Loc. cit., p. 834. 



