ADDRESS. 9 



lying portion) also preceded the deposition of the Old Red Strata. In 

 both of these mountain regions the rocks have since undergone consider- 

 able movements, which in the main seem to have been movements of 

 elevation, accompanied undoubtedly by that constant atmospheric degra- 

 dation to which all high land is especially subject. 



The next great European chain in point of age is that of the Ural, 

 which according to Murchison is of pre-Permian age, a fact proved by 

 the Permian conglomerates which were formed from the waste of the 

 older strata. On these they lie quite unconforraably and nearly undis- 

 turbed on the western flank of the mountains. 



In North America the great chain of the Alleghany Mountains under- 

 went several disturbances, the last (a great one) having taken place after 

 the deposition of the Carboniferous rocks, and before that of the New 

 Red Sandstone. The vast mountainous region included under the name 

 of the Rocky Mountains, after several successive disturbances of upheaval, 

 did not attain its present development till after the Miocene or Middle 

 Tertiary epoch. 



In South America, notwithstanding many oscillations of level recorded 

 by Darwin, the main great disturbance of the strata that form the chain 

 of the Andes took place apparently in post- cretaceous times. 



The Alps, the rudiments of which began in more ancient times, 

 received their gi-eatest disturbance and upheaval in post-Eocene days, 

 and were again raised at least 5,000 feet (I believe much more) at the 

 close of the Miocene epoch. The Apennines, the Pyrenees, the Carpa- 

 thians, and the great mountain region on the east of the Adriatic and 

 southward into Greece, are of the same general age, and this is also the 

 case in regard to the Atlas in North Africa, and the Caucasus on the 

 borders of Europe and Asia. In the north of India the history of the 

 Great Himalayan range closely coincides with that of the Aljjs, for 

 while the most powerful known disturbance and elevation of the range 

 took place after the close of the Eocene epoch, a subsequent elevation 

 occurred in post-Miocene times closely resembling and at least equal to 

 that sustained by the Alps at the same period. 



It would probably not be difficult by help of extra research to add 

 other cases to this notice of recurrences of the upheaval and origin of 

 special mountain chains, some of which I have spoken of from personal 

 knowledge ; but enough has been given to show the bearing of this question 

 on the argument I have in view, namely, that of repetition of the same 

 kind of events throughout all known geological time. 



Salt and Salt Lal-es. 



I now come to the discussion of the circumstances that produced 

 numerous recurrences of the development of beds of various salts (chiefly 

 common rock-salt) in many fonnations, which it will be seen are to a 

 great extent connected with continental or inland conditions. In com- 



