CHAPTER II 

 SOIL FORMATION AND TRANSPORTATION 



Side by side are to be seen rock and soil. On the rock 

 no vegetation is growing except a few lichens and other 

 minute plants. On the soil there is a luxuriant growth of 

 multitudinous plants. Soil is derived from rock. Evi- 

 dently there must have been a profound change to cause 

 such a difference in their relations to plant growth. In 

 some regions of the earth there is much rock and little 

 soil, while often on the prairie one sees no large rocks, and 

 may plow all day and perhaps not strike even a small 

 boulder. It may be surmised that in connection with the 

 process of soil formation there has been a large transporta- 

 tion of material from one place to another. All this was 

 brought about by natural agencies, most of which are still 

 operating to form more soil and to increase the productive- 

 ness of soil already under cultivation. 



The process of soil formation is, however, extremely 

 slow, and it must be remembered that thousands and tens 

 of thousands of years have elapsed while the operation has 

 been in progress. 



9. Agencies concerned in soil formation and transporta- 

 tion. — The agencies that have brought about these trans- 

 formations may be listed as follows : 



Heat and cold Ice 



Frost Wind 



Water Gases 



Plants and animals 

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