108 



MAN AND THE GLACIAL PERIOD. 



Iowa. In the above counties of Minnesota a stratum of 

 peat from eighteen inches to six or eight feet in thickness, 

 with much wood, is pretty uniformly encountered in dig- 



Fig. 36.— Section of till near Germantown, Ohio, overlying thick bed of peat. 

 The man in the picture stands upon a shelf of peat from which the till has 

 been eroded by the stream. The dark spot at the right hand of the picture, 

 just above the water, is an exposure of the peat. The thickness of the till is 

 ninety-five feet. The partial stratification spoken of in the text can be seen 

 about the middle of the picture. The furrows up and down had been made 

 by recent rains. (United States Geological Survey.) (Wright.) 



