504 W. H. HOBBS LINEAMENTS OF ATLANTIC BORDER REGION 



to a single system or network, an explanation is called for which is far 

 removed from local conditions of isostatic crustal adjustments. Linea- 

 ments which can be followed 1,000 miles or more as a definite and rather 

 striking border of plateaux (fT), which are individualized physiograph- 

 ically and geologically, must have an important relation to the orography 

 of the earth as a whole. This idea has been brought out by Suess in con- 

 nection with his study of an almost antipodal region in east Africa,where 

 the dislocations observed were too extended to be explained by local 

 conditions* The stronger lines of displacement being there, as in many 

 other regions, meridional or nearly so, Suess has suggested that they 

 are connnected with a fracturing of the planet, considered as a whole. 

 I quote : 



" These great lines of fracture showing such a peculiar arrangement in space, so 

 far as our present knowledge of them extends, do not allow of a comparison with 

 the fault network arranged peripherally and radially to a trough-like depression ; 

 as, for example, the depressed areas of southern Germany and northern France. 

 . . . The considerable part of the earth's meridian included within the area 

 shows that we have here to do with dislocations which are at least of the order of 

 the furrows upon the moon, if this be a very distant comparison." (Page 135.) 



" The occurrence of such great meridional clefts might easily lead to the view 

 that there is present throughout a tendency toward meridional Assuring, like the 

 fracturing of the planet in the direction of its meridian ; and indeed, so much the 

 more, since the lines of the Laccadive and Maldive islands and the greater number 

 of meridional fractures in the faulted country of the Basin range of North America 

 appear to confirm such an hypothesis." (Page 139.) 



Even more worthy of consideration in this particular are papers b} r 

 Baron von Richthofen, dealing with the geomorphology of eastern Asia,f 

 in which it is clearly shown that the grand features of the entire Pacific 

 coast of Asia are arranged in a system or network made up of a series 

 of tilted plateau-like blocks, the arc-like boundaries of which give form 

 to the great plateau area, as well as to the Asiatic coast line and to the fes- 

 toons of islands which fringe it. According to v. Richthofen, the merid- 

 ional and diagonal series of lineaments are in each case tectonic lines 

 of displacement; the equatorial series which joined to the meridional 

 ones produce the arcs, are in part explained by fold structures. The 

 individual tectonic lines of the series are in some cases 700 miles or more 

 in length, while continuous zigzagging series nearly cross the continent. 



* Eduard Suess : Die Briiche des ostlichen Afrika, Beitriige zur geologischen Kenntniss des 

 ostlichen Afrika, by v. Hdhnel, Rosinal, Toula, und Suess. Part iv, pp. 135, 139. Special reprint 

 from the Denkschriften d. math, naturw. klasse d. k. Akad. d. Wiss., Wien. 



fGeomorphologische Studien aus Ostasien, i-v. Sitzungsber. d. konigl. preuss. Akad. d. Wis- 

 sensch. z. Berlin, 1900-'04. Partial translations have appeared in consecutive numbers of the 

 American Geologist, beginning August, 1904, under the title, Tectonic Geography of Eastern Asia. 



