SOILS. 15 



Transported Soils are those which have been re- 

 moved from their original rock beds by the action of 

 glaciers, floods of water, or by streams which have car- 

 ried soil particles in suspension and deposited them as 

 sediment. In this way decomposed rocks from widely 

 distant localities have become mixed together in an 

 inseparable mass. One form of transported soils is 

 known as the drift which originated during the Glacial 

 Epoch, a period when the present surface of the coun- 

 try was covered to a great depth with fields of ice. 

 This kind of soil is usually distinguished by rounded 

 rocks of various sizes called boulders, and by fragments 

 of rocks whose edges have been rounded by friction, 

 all of which are incorporated with the soil proper. As 

 might be correctly inferred, the varieties of soil found 

 in the area affected by glacial action include every pos- 

 sible shade of difference. The moving glacier from 

 whose melting mass rocks and clumps of soil were con- 

 stantly being deposited, and subsequently ground by 

 the passing mountain of ice, formed one of the later 

 geological epochs and one which is of great interest 

 and importance to the northern part of the United 

 States and Canada and as far west as western Iowa. 



Alluvial Soils consist of worn and rounded mate- 

 rials which have been transported by the agency of 

 moving water and deposited as sediment. The pos- 

 sible conditions under which soils can be formed in this 

 way are without number. Alluvial deposits have been 

 formed in all periods of the world's history. Water 

 trickling down a granite slope carries forward the kao- 

 linite arising from decomposition of feldspar, and the 

 first hollow gradually fills up with a bed of clay. In 



