AGES OF MOUNTAIN SYSTEMS. 



from the first consolidation of its external crust to the present 

 epoch. Since it has been found in Europe (the only part of the 

 world which has hitherto undergone sufficiently accurate geological 

 survey), that the various ridges which have the same or parallel 

 directions belong to the same epoch of elevation, analogy would 

 justify a similar inference respecting all parts of the globe, and 

 we should naturally conclude that parallel lines of direction and 

 contemporaneity of formation are interchangeable principles. It 

 is at least interesting to examine from this point of view the 

 principal chains which are known in different parts of the earth. 



To show how far the results of these observations in Europe 

 may be generalised by such analogies, M. Elie de Beaumont 

 designed for M. Beudant the plan which, by their permission, 

 we have reproduced in fig. 132, showing the generalisation of the 

 classification of mountain systems according to their dates, as 

 above explained. 



It will be seen upon this chart that the direction of the system 

 of the Pyrenees extends from the Alleghanies in North America 

 to the Indian Peninsula by the Carpathians, Mount Caucasus, the 

 mountains of Persia, and the Ghauts in India. To the south of 

 this line there are several parallel ridges, such as those which run 

 from Cape Ortegal in the Asturias to Cape Creux in Catalonia. 

 Also the little range of Grenada, the mountains which surround 

 the southern side of the desert of Sahara, intersecting the direction 

 of the Atlas, and, in fine, the Apennines, the Julian Alps, and the 

 mountains of Croatia and Ptoumelia, extending to those of the 

 Morea. 



The system of the Ballons, so closely related in direction to that 

 of the Pyrenees, is also represented in the Alleghanies. 



The direction of the system of the "Western Alps is observed 

 from Morocco to New Zealand, passing along the eastern coast of 

 Spain, the south of France, and a great part of the Scandinavian 

 peninsula. Parallel ridges are found in the Cordilleras of Brazil, 

 in the regency of Tunis, in Sicily, at the point of Italy, and in 

 Asia Minor. All the littoral range of the old continent, from the 

 northern cape of Lapland to Cape Blanco in Africa, partakes of 

 this direction. 



The direction of the principal Alps is in accordance with 

 numerous other ridges. Chains parallel to this direction are 

 found in the Atlas, in Spain, and across the old continent to the 

 China Sea, including Mount Olympus, the Balkans, the Taurus, 

 the central chain of the Caucasus between the Black Sea and the 

 Caspian ; in the long series of mountains which extend through 

 Persia and Cabul, including the Parapamisan mountains in 

 Afghanistan and eastern Persia, the range of the Hindoo Koosh, 



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