188 F. B. TAYLOR ORIGIN OV THE EARTH's PLAN 



The trend-lines of the mountain ranges as shown on this map are, of 

 course, somewhat distorted, especially in eastern Asia and in Europe, 

 but they are much less distorted than when represented on Mercator's 

 projection, and the proportions of the parts of- Eurasia are more nearly 

 true. The dotted areas east of Japan and south of the Aleutian arc are 

 frontal ocean deeps. 



SuEss' Method of Interpretation 



Suess interprets the structure of Asia chiefly hy a study of the hori- 

 zontal plan of its mountain ranges. These ranges mark the main struc- 

 tural or tectonic lines of the continent, and in the peculiar arctuate forms 

 which characterize them, in the relation of the arc-shaped ranges to one 

 another, in their magnitude, arrangement, and distribution with refer- 

 ence to the continent as a whole, and also in their relative ages and the 

 order of their formation, Suess finds a stronger and more certain light 

 shed upon the structure of Asia and upon the origin of that structure 

 than in all other evidence combined. Suess has reached his grand con- 

 clusions as to the direction of crustal creep and horizontal thrust, not by 

 the usual method of studying outcrops and cross-sections, but by a study 

 of the trend-lines of the mountain ranges which were produced by these 

 movements. 



This method is imique, but it grew naturally and easily out of the 

 study of the facts observed, and is not a fanciful invention of the imag- 

 ination. As Suess has said, the arc-shaped ranges of Asia have deeply 

 impressed all the students of that continent. They are the most re- 

 markable and significant thing which the researches in that continent 

 have revealed. While similar investigations have been carried on in all 

 the other continents, this method of interpretation was not developed in 

 any of them, for the evident reason that no other continent has mountain 

 systems which reflect in their plans such simple and unequivocal expres- 

 sions for the dynamic forces involved in mountain and continent making. 

 But, having been developed in Asia, this method may possibly be applied 

 with success to the interpretation of the other continents. 



So strongly significant of crustal movement in one general direction 

 are the lines of the mountain plan of Asia that no geologist who at the 

 outset was free from strong hypothetical preconceptions has failed to 

 agree with Suess in his general interpretation. Not that the other geol- 

 ogists join with Suess in the details of his particular hypothesis of the 

 causes of Asiatic structure, but the general consensus of opinion among 

 European students of Asia agrees with him in his broad conclusion that 



