183 



portant mouritain making of later date. They retain substantially un- 

 changed the forms which Tertiary diastrophism gave them. Hence, 

 whatever characteristics or peculiarities of form or plan mountain- 

 making forces are wont to impress upon their products, these ought 

 surely to be discernible in a mountain system which is at once the newest 

 and most extensive upon the earth. Indeed, the Tertiary mountain belt 

 stands out so prominently as the product of a recent, distinct, and ap- 

 parently completed epoch of mountain making that within certain limits 

 it can be studied by itself, without much reference to older mountain- 

 making epochs. 



It is admitted by all that the mountains of the great Tertiary belt,- 

 like the older ranges of fold-mountains, were produced chiefly by com- 

 pressive forces acting in a horizontal direction, and that the total amount 

 of compression involved is equivalent to many miles of horizontal move- 

 ment of the earth^s crust. What was the nature of those movements? 

 In what direction did the crust move in producing the Tertiary moun- 

 tains of Asia — from the ocean toward the land or from the land toward 

 the ocean ? This is the crucial point. 



There is a considerable body of facts which bear strongly upon this 

 question; a few of the more important are briefly set forth below in a 

 discussion of the origin of the Tertiary mountains, and the conclusions 

 thus reached seem to throw some new light on the origin of the earth's 

 plan. 



SuEss' Interpretation of the Plan of Asia 



In his great work, "The Face of the Earth,'' the eminent Austrian geol- 

 ogist, Eduard Suess, has devoted much space to the consideration of the 

 continent of Asia. As a result of his extensive studies, Suess reached 

 the conclusion that, in consequence of the cooling and shrinkage of the 

 earth as a whole, all parts of the crust have settled or sunken down toward 

 the center, the ocean basins most and the high continental areas least. A 

 few quotations will show the general character of his conclusions. After 

 noting the contrast between the outlines of the ocean basins and the 

 structure of the continents, Suess remarks that ^Hhese ocean basins are 

 areas of subsidence''^ (II, 536), "As soon as we recognize the ocean 

 basins as sunken areas, the continents assume the character of horsts" 

 (II, 537). "The crust of the earth gives way and falls in; the sea fol- 

 lows it. But while the subsidences of the crust are local events, the sub- 



'^ Unless otherwise stated, all quotations from Suess are from "The Face of the Earth." 

 authorized English translation by Sollas. Reference Is made to volume and page. All 

 of the Italics In the quotations belong to Suess. Pour parts of "The Face of the Earth," 

 In three volumes, have been published at the time of this writing. 



