26 



THE SOIL 



Sedentary Soils. These are soils which rest upon the rock from 

 which they were formed. Their composition is similar to that of 

 the rock underneath, with vegetable matter added by the growth 

 of plants upon them. 



Transported Soils are those that have been deposited from 

 water and ice after being transported, perhaps, hundreds of miles 

 from the parent rock. 



Alluvial Soils. Soils deposited from water are called alluvial. 

 They form fertile loams and are usually rich in organic matter. 



Bowlders deposited by a glacier. 



These alluvial soils occur in valleys, river beds, and also in beds of 

 former lakes now far inland. 



Drift Soils. Soils deposited from ice are called drift soils. 

 They may be distinguished from others by the presence of round 

 rocks or bowlders. They are formed by the action of glaciers which 

 are vast bodies of ice moving like a river carrying vast quantities 

 of earth and stone. 



The Glacial Age. Many hundreds of years ago there came a 

 long cold winter which destroyed nearly all forms of plant and 

 animal life. Snow and sleet fell day after day until an immense 

 glacier or body of ice several hundreds of feet in thickness was 

 formed. One of these glaciers, a thousand feet thick and a thou- 



