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UNCLE IN ENGLAND. 281 



this fact, that the rocks from which those frag- 

 ments were derived must have been exposed to 

 the action of violently agitated water, which tore 

 off these masses, and rounded them by friction, 

 before the newer rock, in which the fragments 

 are now imbedded, was formed. Another con- 

 clusion he draws from it, is this : these rocks 

 were undoubtedly at some former period, beds of 

 loose gravel ; but loose gravel could never have 

 been left by the water piled up in a highly in- 

 clined slope : we may therefore be sure, when 

 new sandstone and other rocks of the same kind 

 are found in nearly vertical strata, that this can- 

 not have been their original situation, but that 

 they must have been forced into their present 

 position by some convulsion after their consoli- 

 dation. These consolidated gravel beds are 

 called conglomerates, breccias, or pudding- 

 stones, according to the materials of which they 

 are composed. 



He told us that the remains of marine animals, 

 such as we saw the other day, are found in two- 

 thirds of the rocks that compose the surface of 

 the globe ; and even on the highest summit of the 

 Pyrenean mountains in Europe, and of the Andes 

 in America. From this important fact, it is 

 ascertained, without the possibility of doubt, that 

 those continents have not only been covered by 

 the ocean, but that they are formed of materials 



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