GEOLOGICAL INVESTIGATION. ,J 



The intermixture is attended by mechanical and 

 chemical changes in the stratified rocks. 



They have been consolidated after fusion, and their 

 structure is necessarily chemical. 



Volcanic rocks present all the same characters. 



An unstratified or a volcanic rock may be of later 

 origin than the stratum above it. 



FRAGMENTS. 



These consist of portions of rocks, of minerals, of 

 earths, and of vegetable and animal substances. 



They occupy the surface of the solid earth, either 

 above the water or beneath it. 



They have been produced by the destruction of 

 rocks, and by vegetables and animals. 



They have been deposited by gravity and by the 

 motion of water. 



ACTIONS. 



Actions are the results of animal and vegetable life 

 and destruction, of water and the force of gravity, or 

 of fire. 



By organic production and destruction, its objects 

 become portions of the Fragments, or form Strata, 

 or parts of these. 



By WATER and GRAVITY, the solid rocks are broken 

 into fragments, and deposited on the land or beneath 

 the water 



By WATER, animal remains are mineralized, and 

 vegetable ones bituminized; both classes of change 

 being of graduating characters. 



FIRE acts in Volcanoes, which are visible or in- 

 visible. 



It elevates the superincumbent materials of the 

 earth, whether solid or otherwise. 



