On the age of Mountains, 



527 



de Beaumont has treated, and the problem which he has in 

 a satisfactory manner solved. 



Amongst the very different masses of which the earth's 

 surface is composed, there is found a class, which forms 

 what is called flots bjerge ; i. e, mountain masses of sedi- 

 mentary stratified rocks. 



The real flots bjerge, consists entirely or partly of sand, 

 mud, and finely divided masses, which have been carried 

 away by the water like the mud in our rivers, or the sand 

 at the sea coast. This more or less fine sand, formed af- 

 ter it had been cemented by lime as a clayish mortar, that 

 kind of mountain which is called sandstone. 



Certain sorts of limestone belong also to flots bjerge; as 

 those remains of shells which are found in them, in an an- 

 other and still clearer manner proves that they were formed 

 in waters. Flots bjergene consist always of considerable lay- 

 ers, which rest on each other. To these formations belong 

 principally the following, which are here ranked according 

 to their ages : — 



1. Coal formation. 



2. Jura limestone. 



3. Green sand and chalk. 



4. Tertiary formation. 



5. The early tertiary uplifted land. 



6. Quaternary formation, consisting of the newer upwashed 



land.* 



Although all these varieties of mountain masses were depo- 

 sited by water, and are found collected and grouped above 

 each other, yet the passage from one to another is not 



* The coal formation contains the great beds of coal which lie in sand- 

 stone, distinguished by the many impressions of ferns found in it. 



The Jura limestone is a whitish limestone, sometimes compact, close, 

 and even, as the stone serves for Lithography, and sometimes consists 

 of small round grains (rognsteen i. e. pea-stone, or oolite). The name 

 is derived from the Jura chain, which mostly consist of this mass. 



The green sand and chalk formation consists of sandstone layers, 



