THE ORIGIN OF THE SOIL 7 



banks are the result of the water sorting out the finer parti- 

 cles, carrying them away, and depositing the coarser sand 

 and gravel in depressions. 



The wind has had a good deal to do with transporting soil. 

 We have seen the wind drifting snow in the winter time. 

 Just so it drifts soil in many parts of the world. The ma- 

 terial carried is usually sand and forms sand dunes. Along 

 the southern border of Lake Michigan in Indiana are many 



I. LAND DAMAGED BY WASHING 

 By courtesy of the Indiana Experiment Station 



large sand dunes which have buried considerable areas of 

 forest. Such land in its present condition is worthless for 

 farming purposes. All wind-carried soils, however, are not 

 worthless. In some parts of this country there are large areas 

 composed of very fine particles, quite deep and fertile. These 

 wind-formed soils are called loess soils. They are found 

 mostly west of the Mississippi River. 



We should notice here that the soil is likely to be washed 

 away. Some soils wash more than others. Soils composed of 

 very fine particles wash most readily, because the rain water 



