7O PRINCIPLES OF AGRICULTURAL CHEMISTRY 



The northern part of the United States was once covered by a 

 great glacier sheet, stretching down from Canada. Glacial soils 

 are accordingly found in New York, Ohio, and other Northern 

 States. Some of these deposits have been reworked by rivers 

 until their glacial characteristics are no longer easily recognized. 

 Glacial soils are especially important in New York and states 

 north of it, and in the states north of the Ohio and Missouri 

 rivers. They frequently contain considerable amounts of car- 

 bonate of lime. 



Fig. 20. Hypothetical map of glacial sheets of North 

 America. Salisbury. 



The waters from the melting of the glacial sheet also carried 

 ground-up material. Though this was sorted by the water, it is 

 different from ordinary alluvial soils. These soils are found in 

 the area adjacent to the glacial regions. 



Loess, finely ground material derived from glacial drift and 

 transported by winds or flowing water, consists of grains of 

 quartz, feldspar, mica, hornblende, with some limestone and clay. 



