3IO HISTORY OF GEOLOGY AND PALEONTOLOGY. 



elusion. On the eastern boundary of the aforesaid region a 

 number of disturbances were apparent, which were frequently 

 associated with volcanic phenomena, and had caused the 

 tremendous north-south fault of the Red Sea and the 

 Jordan valley, also influencing the direction of strike of 

 the Ural mountains and the western Ghats. East of this 

 transversal line of disturbance, the leading Asiatic mountains 

 had not in Europe the convex side of the strike-curves towards 

 the north, but the convexities were towards the south. 



A comparison of the Himalayas with the Alps showed a 

 remarkable agreement between the two distant mountain- 

 systems; Mesozoic, Palaeozoic, and Crystalline rocks com- 

 posed the high mountain-lands of both systems, yet there 

 was the fundamental difference that the Tertiary rocks 

 in the southern foreground of the Himalayas corre- 

 sponded with those in the northern Molasse Zone of the 

 Alps. Medlicott had already concluded from the general 

 structure of the Himalayas that the chain had taken origin 

 as the result of lateral compression from the north, and Suess 

 tried to demonstrate a similar direction of movement, to the 

 south or south-east, in other systems of Central Asia. 



Suess agreed with Dana's opinion that the sedimentary rocks 

 of the Euro-Asiatic systems had accumulated in pelagic geo- 

 synclinals; and he brought the frequent gaps and uncon- 

 formities in the succession of strata carefully into relation with 

 former oscillations in the extent of the ocean. Suess described 

 in greater detail the transgression of the Cenomanian Ocean 

 which spread over a considerable part of Europe, North and 

 South America, and northern Africa, and drew from it the 

 conclusion that stratigraphical evidences of transgressions 

 and withdrawals of the waters of the ocean were even more 

 valuable as a means of determining the approximate eras of 

 certain events in the Earth's history than the discovery of the 

 relative ages of mountain-systems. 



In the concluding chapter of this work on the origin of the 

 Alps, Professor Suess summarised his results as follows : 

 the strikes of mountain-chains do not always run parallel with 

 the greater circles of the earth, but may be diverted by various 

 obstacles; the major fold-systems of mountains take origin 

 frequently, if not exclusively, in geo-synclinals and demand 

 enormous periods for their development. Volcanoes play a 

 subordinate part in the formation of mountains. Most 



