THE CRUST OF THE EARTH. 



and transporting vessels of the largest tonnage to a distance of 

 four miles inland. 



102. When such effects arise from a change of the surface not 

 exceeding a few feet in elevation, it may be imagined what pro- 

 digious deluges must have been produced when the Alps and 

 Pyrenees were raised to heir present altitude from the ordinary 

 level of the earth's surface, or when the chain of the Andes was 

 elevated by a dislocation, which mustjiave extended over nearly 

 3000 miles of the earth's surface. 



It cannot then be doubted that the consequence of such con- 

 vulsions would be universal ; and some idea may be formed of the 

 extraordinary ravages which the frightful deluges consequent 

 upon them would occasion upon the surface of the earth, especially 

 at the moment when all levels of land and sea were changed in 

 consequence of the dislocation which caused them, and when a 

 considerable mass of sediment still in a movable state was trans- 

 ported by the torrents of the ocean. It will not be considered 

 extraordinary, that all the terrestrial animals should be at once 

 destroyed by the immediate action of the waters, while the marine 

 animals would suffer equal destruction by the violent transport 

 of the terrestrial matter swept among them. 



103. M. Elie de Beaumont has shown that these movements of 

 terrestrial dislocation have never been partial, but that each of 

 them has been produced along lines, having one uniform direction, 

 as may be seen in the case of the Pyrenees, of certain ranges of 

 the Alps, and upon a still greater scale in the case of the Andes 

 and the Himalayas. "We shall show more fully hereafter that the 

 parallel lines of mountains have been raised at the same epoch, 

 and that the succession of convulsions by which the ranges of 

 mountains having different directions were produced, can be de- 

 termined, and their geological dates assigned with more or less 

 precision. 



104. The circumstances which have been explained, attending 

 the past history of the earth, have also produced cracks and 

 fissures in its crust, through which the central liquid matter has 

 been forced, and in which it has been solidified, forming veins of 

 mineral matter different altogether from the strata which they 

 intersect. These veins often contain earthy matter, such as 

 carbonate of lime, sulphate of baryta, and quartz, in which case 

 they offer but little interest. They are, however, more frequently 

 filled, either wholly or partially, with metalliferous substances, in 

 which case they acquire great importance. These metalliferous 

 veins are generally found either in the igneous or in the most 

 ancient of the stratified rocks. 



105. It is rare that a single vein is met with. Most commonly 

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