39. 



SYSTEMS OF ELEVATION. 87. 



encircling their base in an unconformable position, it is 

 evident that the mountains must have been elevated 

 before the formation of the latter deposits. 



It is by cautious inductions of this kind, that a distin- 

 guished savant, M. Elie de Beaumont, has shown, — 1. 

 that the mountain-chains of Erzgebirg, in Saxony, and of 

 the Cote d'Or, in Burgundy, are newer than the Jura lime- 

 stone, but older than the greensand and chalk. 2. That 

 the Pyrenees and Apennines are of about the same age 

 with the chalk formation. 3. That the western part of the 

 Alps is of later origin than the older tertiary formations, 

 and was raised up after the last of the newer pliocene were 

 deposited. 



The Caernarvon chain was elevated anterior to the 

 deposition of the mountain limestone, for the latter wraps 

 round it like a mantle.* 



Professor Phillips infers, that when the Grampian hills 

 sent forth streams loaded with detritus to straits where 

 now the valleys of the Clyde and Forth meet, the greater 

 part of Europe was beneath the sea. For the Pyrenees 

 and Carpathian mountains are younger than the Grampians 

 and the Mendip hills. 



That the sudden protrusion of such immense masses as 

 the Alps or Pyrenees from the bottom of the ocean, must 

 have dislodged vast volumes of water, and created a series 

 of waves high and powerful enough to cause transitory but 

 destructive inundations over such portions of the adjacent 

 dry land as were only a few hundred feet above the level 

 of the sea, cannot be doubted ; but if the elevations were 

 gradual, such effects would take place only in a very slight 

 degree. 



39. Systems of Elevation. — From the facts and ob- 

 servations that have been adduced, it is sufficiently obvious 



* Professor Sedgwick. 



