26 THE STORY OF THE EARTH. 



CHAPTER IV. 



VOl RO< k>. 



\ lear distinction can be drawn beta 



plutoni< v crystalline forms of 



Both truded in some in- 



• cd parts of the earth. In 

 • the rigid condition of tin . 

 it is imj that those rocks came to the sur- 



al an 111 (dated interior by . a 



Many writers have assumed the 



• molten i >r lakes in the interior 



of the crust, as a source for lava streams, which 



surface for a hundred 



(>ti -line that the longitudinal 



which volcanic cones have been 

 buill wn to different la the 



t< h distinguished by having the min< 



f the- different kinds of volcanic r< 



i all< '\\ b the- atmosphere to p< 

 I removes from the heated i 



had kept it solid. The i 



liquefies and a the fissure like fluid in 



imp, until it comes in contact with water de- 



•m the- earth's mii fa< c, and S< 



:n, whi( the expl< >sh e i outbursts. I 



high int" ll 

 up | . in the- • dust. The du 



,. m the Strait nda, 



I suspended for n 



thai 



cc between 

 plot ks is in the i in urn- 



