dtjfcrent European Chains (tf Mountains. 299 



It is now evident that the sedimentary formations whose beds 

 present themselves on the slopes of mountains, in inclined or 

 vertical directions, existed before these mountains were reared. 

 The equally sedimentary formations which prolong themselves 

 Juyrizontally until they meet these slopes, are, on the contrary, 

 of a date posterior to that of the formation of the mountain : for 

 it cannot be conceived that, in issuing from the ground, it should 

 not have raised at once all the beds that existed in the district. 



Let us place proper names in the general and very simple 

 theory which we have just unfolded, and M. de Beaumont's 

 discovery will be proved. 



Of the four species of sedimentary formations which we have 

 above distinguished, three, and they are the highest, the near- 

 est to the surface of the globe or the newest, are prolonged in 

 horizontal beds from the mountains of Saxony, the Cote d'Or, 

 and Forez ; one, the Jura or oolite limestone, alone is seen raised. 

 Therefore the Erzgebirge, the Cote d'Or, and Mount Pilas in 

 Forez have issued from the globe after the formation of the 

 oolite limestone, and before the formation of the other three se- 

 dimentary deposites. On the slopes of the Pyrenees and Ap- 

 penines, there are two raised formations, viz. the oolite lime- 

 stone and the green-sand and chalk formation. The tertiary 

 formation and the alluvial formation which cover it have pre- 

 served their original horizontality. The mountains of the Py- 

 renees and Appenines are therefore more modern than the Jura 

 limestone and the green-sand which they have raised up, and 

 older than the tertiary formation and the alluvial formation. 



The western Alps (among others Mont Blanc), have raised, 

 like the Pyrenees, the oolite limestone and the green-sand ; but 

 they have, rnorcover, raised the tertiary rocks ; the alluvial 

 depositc alone remaining horizontal in the neighbourhood of 

 these mountains. The rising of Mont Blanc must, therefore, 

 have been between the period of the formation of the tertiary 

 rocks and that of the alluvial deposite. Lastly, on the sides of 



tains the vertical position, these lines will be themselves vertical. The lines 

 placc'l orif^iiially in directions intermediate l)etween those of these two sys. 

 terns, will form with the horizon an^rlcs com[)rised lictween fl' and 90'. Now, 

 this is tiic pruxisc imaf^c of the disposition which the large axes of the pcb- 

 bles affect in the raised strata. 



