20 



SOIL COMPOSITION, CLASSES AND TYPES 



courses, and, when the ice melted a new soil called ^'glacial drift^^ 

 was laid down. Most of this ^' drift ^^ material was not carried 



Fig. 10. — Whence came this large bowlder? •' The glaciers brought it many miles from the 

 north. The machine in the'background is a stone puller. (Wisconsin.) 



Fig. 11. — Karnes — round and oval hills formed through glacial action. Wisconsin Geol. 



Survey. (Fenneman.) 



any great distance by the glaciers, though the streams which ran 

 from the melting ice carried much sediment miles beyond the 

 area covered by the ice sheets, and deposited it, as alluvium, 

 in their valleys. 



