differ ait European Chains of Mountains. 295 



. Sucb aue precisely the questions which have engaged the at- 

 tention of M. EHe de Beaumont ; and there is reason to think 

 that he has, in some degree, solved them. The follo)ving are his 

 results. I shall afterwards pass to the proofs. 

 ; The system of the Erzgebirge in Saxony, the Cote d'Or in 

 Bourgogne, and Mount Pilas in Eorez, is the first that has been 

 raised of.aU tlite mountainous districts which, M. de Beaumont 

 has yet considered. The system of the Pyrenees and . Appe- 

 nines, although more extensive and of greater elevation, is of a 

 much less ancient date. The system of the western Alps, of 

 which the colossal mass of Mont Blanc forms a part, was raised 

 long after the Pyrenees. , Lastly, a fourth raising, posterior to 

 these just mentioned, has given rise to the central Alps, (St Go- 

 thard), the Ventoux and Leberon Mountains, near Avignon, and 

 in all probability, to the Himalayan Mountains in Asia, and the 

 Atlas range in Africa. 



I have presented these results first, in the hope that their sin- 

 gularity may engage . the reader to follow with more attention 

 the somewhat minute details which will enable us to determine 

 their accuracy. 



Among the numerous and diversified deposites of which the 

 crust of the globe is composed, there are some which have been 

 named sedimentary formations. 



The sedimentary formations properly so called, are composed, 

 in whole or in part, of detritus carried along by the waters, similar 

 to the mud of our rivers, or the sands of the sea^shore. These 

 sands, more or less comminuted, agglutinated by calcareous or 

 sihceous fluids, form the arenaceous rocks called sandstones. 



Certain limestone formations are also ranked among those 

 which are called sedimentary, even although, which is rarely the 

 case, they leave no sedimentary residuum after being dissolved 

 in nitric acid, the remains of shells which they contain shewing 

 in another and perhaps still better manner, that their formation 

 has also taken place in the bosom of the waters. 



The sedimentary formations are always composed of very dis- 

 tinct successive beds. The more recent may be divided into 

 four great sections, which, in the order of their antiquity, are 

 the following :— Oolite or Jura limestone — The green-sand and 



t 



