128 IOWA ACADEMY OF SCIENCES. 



lation around its margin of deposits of sand and loess by 

 the overwash of materials liberated from the melting ice, 

 and by the action of winds sweeping over the surface of 

 the ice sheet and laying down their load to the leeward of 

 its margin. 



As a consequence of such deposition the Kansan hills 

 immediately around the border, which had been leveled 

 down to some extent by the ice moving over them, were 

 built up to a height twenty to thirty feet above the more 

 elevated points in the southern portion of the lobe. Dur- 

 ing this time, also, much of the hne-grained loess mate- 

 rials gathered up by the winds would be carried out for 

 some distance beyond the margin of the ice, and thus the 

 southern portion of the lobe would receive a mantle of 

 loess above the lowan drift which had been previously 

 deposited over the area. When the ice melted there was 

 left the belt of sand or loess-covered hills, one-half mile to 

 a mile in width, which forms so conspicuous a feature 

 across the north central portion of the lobe. 



Some time before the entire withdrawal of the lowan 

 glacier from the county, the flow of ice ceased over the 

 northern portion of the lobe, the margin retreated to 

 about the same distance southward as that of the main 

 body of lowan ice. Along this border a new series of 

 ridges was formed, but the width of this belt is less than 

 that of the one which crosses the central portion of the 

 lobe. The individual ridges are also lower and less con- 

 spicuous. Pleasant Hill church, situated about the middle 

 of the south sid.e of section* 2 of Howard township, is 

 located on one of the ridges of this moraine. 



After the retreat of the ice from the Toledo lobe, and 

 probably before the entire withdrawal of the lowan sheet 

 from this part of the state, a mantle of loess was depos- 

 ited in places over the northern portion of the area under 

 consideration. 



With this deposit and the retreat of the ice the stage of 

 the lowan ice invasion was closed. From that time, so 

 long ago when measured in years yet so recent from a geo- 

 logical point of view, the forces of weathering and erosion 



