278 THE ILLINOIS GLACIAL LOBE. 



On the outer border of the moraine in eastern Ogle Comity there is a 

 depression due to a preglacial valley which was not completely filled. Into 

 this depression considerable sand and fine gravel was earned by the waters 

 issuing from this moraine. There were two lines of escape, the southern 

 portion of the depression being drained westward through Kite River, while 

 the northern portion was drained northward through Killbuck Creek. The 

 sandy and gravelly deposits are thickest along the portion drained by Kill- 

 buck Creek, where they have a depth of 20 feet or more. In the portion 

 drained by Kite River the average depth is but 5 or 10 feet, and portions 

 of the depressed area have scarcely any surface gravel. The deposits in 

 this depressed tract would be classed as a gravelly sand rather than gravel, 

 the proportion of coarse material being very small. The streams issuing 

 from the moraine in Dekalb County (South Kishwaukee River and Owen's 

 Creek) have only a small amount of gravel and sand outside the moraine, 

 and appear not to have been lines of vigorous discharge. Sandy material 

 borders Owen's Creek for about a mile each side the stream from the vicinitv 

 of South Grove northward to the mouth. The material is fully as fine as 

 that on Killbuck Creek. On the Kishwaukee the belt of sand and gravel 

 is less definitely outlined, there being places where no sand or gravel is 

 found on either side of the valley, while at other places it extends back 

 southward from the valley to the moraine, a distance of a mile or more. It 

 is probable that a portion of this sand and gravel is an outwash connected 

 with the formation of the moraine, though it connects rather vaguely with 

 the moraine. 



In northwestern Kane County a plain of sandy gravel extends from 

 the moraine westward to the valley of Coon Creek and leads thence down 

 the valley to the north Kishwaukee. It there connects with belts of gravel 

 which lead in from the east and north, all of which appear to be an out- 

 wash from the western border of the composite belt of moraines in 

 McHenry County. A broad belt of gravel leads down the north Kishwau- 

 kee to its junction with the south branch near Cherry Valley. Below this 

 point the valley is so narrow that gravel terraces are inconspicuous, though 

 they continue to the Rock River Valley. 



The conditions of drainage attending the formations of the minor 

 moraines is next considered. The character of the outwash from the weak 

 moraine in northern McLean County has received but little attention. 



