HOW IS SOIL MADE? 



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are being leveled, our river valleys cut deeper, and soil 

 is being deposited far from where it was originally made 

 from rock all by this force of erosion. Erosion is a 

 leveler which is carrying mountains into the oceans, and 

 producing many other changes in land forms over the 

 surface of the earth. 

 Erosion in its broad- 

 est meaning includes 

 weathering. 



Erosion by Water. 

 The mountains of 

 Switzerland and many 

 of our western peaks 

 are huge rock masses 

 which are being worn 

 slowly away by water. 

 The force of the water 

 loosens the big bowl- 

 ders, rolls rocks down- 

 stream, rubbing one 

 against another, and 

 causing them to be 

 ground into powder. 

 In many a mountain 



Stream today ,We may A view in the Carlsbad Caverns. Notice the 



866 this powdered ma- stalactites and stalagmites formed from min- 

 . erals once held in solution in water. 



tenal going down with 



the turbid water to be deposited at the river's mouth in 



the form of a delta. 



Erosion by Wind. In many parts of the world, the 

 wind has an important part in soil making. In some 

 parts of western United States, the wind drives millions 

 of particles of sand against the sandstone cliffs with such 

 force that they are worn down and hollowed out by this 

 natural "sand blast." 



Carlsbad Chamber of Commerce 



