COMPOSITE MORAINIC BELT OP NORTHERN ILLINOIS. 299 



among the gravelly ridges. In a few cases the knolls and ridges appear on 

 elevated parts of the district. 



In Campton Township (T. 40, R. 7 E.) the moraine is very elevated, 

 some points reaching nearly 1,000 feet above tide, and presents a very sharp 

 knob-and-basin topography. It has probably the sharpest knobs and the 

 deepest basins found in the State of Illinois. The highest points rise about 

 150 feet above the border districts on the south and west and more than 200 

 feet above Fox River. Oscillations in level of 75 feet in a distance of 30 to 

 40 rods are not uncommon, and several beautiful lakelets of an acre or 

 more each are sunk deeply in the midst of morainic knolls which surround 

 them. This very strongly morainic topography appears at the point where 

 the inner belt of the Bloomington morainic system connects with the com- 

 posite belt under discussion. It also terminates the prominent portion of 

 the composite belt so far as developed west of Fox River. 



Upon passing southward from Campton Township a much lower 

 country is entered than that to the north, the descent being similar to that 

 found in passing southward from the inner border of the Bloomington 

 morainic system 1n western Kane, Dekalb, and Lasalle counties. But 

 instead of passing into a plane-surfaced tract, such as occurs on the inner 

 border of the Bloomington system, an undulating tract is entered, which 

 extends south to the border of Kendall County in a belt several miles wide. 

 This tract contains a few very prominent knolls. One, known as Johnsons 

 Mound, situated near the east fork of Blackberry Creek in sec. 15, T. 39, 

 R. 7 E., rises about 150 feet above the level of the creek and covers fully 

 50 acres. A second prominent knoll, known as Bald Mound, because desti- 

 tute of trees, is situated in sec. 23 of the same township. It rises about 80 

 feet above the border districts and covers perhaps 1 00 acres. It is elongated 

 in a north-south direction, its length being about three times its width. Its 

 southern end rises abruptly, but at the north it descends gradually to the 

 gently undulating tract which borders it. A third knoll, known as Wash- 

 burn's Mound, is situated between the other two in sec. 14, and stands about 

 50 feet above the bordering country. This mound is also elongated north 

 to south, and has a length of one-half mile and a width of 40 to 60 rods. 

 This mound has a more regular border than the other two, for they present 

 spur-like projections which extend out 20 to 40 rods beyond a regular 

 border. Aside from the three prominent mounds just mentioned the knolls 



