50 SOILS 



This is probably more varied than most drift 

 soils, but it shows the extent to which the ice, and 

 streams of water produced by the melting of ice, 

 have assorted and mixed the soils and soil ma- 

 terials of the Northeast. 



The value of drift soils for cropping is very 

 variable, depending upon the material of whicn 

 they are composed, and the way in which they are 

 laid down. As a rule, however, they are fertile be- 

 cause they are composed of materials that have 

 been brought together from several sources, and 

 there is therefore greater likelihood that the essen- 

 tial plant foods will be present in abundance. They 

 are apt to contain more sand or gravel and less 

 clay than sedentary soils; hence they are 

 usually of good texture and easily worked. But a 

 drift clay or muck is not more valuable or manage- 

 able than a sedentary clay or muck. Those con- 

 taining a fair percentage of clay are more valuable 

 than those that consist chiefly of gravel. 



Wind-built Soils. Still another type of trans- 

 ported soils those built mostly by wind is some- 

 times very valuable for cropping. The wind- 

 formed soils of Washington and Oregon are com- 

 posed of fine basaltic ash. The loess and adobe 

 soils discussed further on have been made partly 

 by wind. More frequently, however, wind-formed 

 soils are of little or no value, being composed 

 mostly of fine sand ; and moreover, they may cover 

 and ruin other soils that are valuable. On the 

 southeast shores of Lake Michigan sand dunes 

 100 to 200 feet high have buried large areas of 

 forest. The sand hills of Wyoming cover about 

 20,000 square miles of territory on both sides of the 

 Niobrara River. These are a part of the "Bad 

 Lands," a dreary waste of naked, rounded hills, 



