76 



FIRST YEAR SCIENCE 



rocks to see whether they are affected by it. Describe in a general 

 way the characteristics of each specimen. 



The composition of differ- 

 ent land areas varies greatly. 

 Many different kinds of rocks 

 are often found crowded to- 

 gether, or it may happen that 

 the same kind of rock covers 

 a large area. There is no uni- 

 formity. The soil on top of 

 the rock is also variable. In 

 some places it contains the 

 minerals which are in the rock below and in other places 

 its composition is not at all dependent upon the bed rock. 



GRANITE. 



Igneous rock formed deep below 

 the surface of the earth. 



FOSSIL-BEARING LIMESTONE. 

 A sedimentary rock formed from sea shells. 



The great variety of rocks of which the crust of the 

 earth is composed has been divided into three great 



