320 THE ILLINOIS GLACIAL LOBE. 



ridged belt borders the river quite closely and part of the city stands on it. 

 From that city it takes a course slightly north of east to Exline, cutting 

 across the great bend in the river opposite the mouth of the Iroquois River. 

 Some uncertainty is felt as to its continuation from this point. It may 

 continue eastward into Indiana parallel to the river and pass beneath the 

 Valparaiso moraine, though it seems quite as probable that it finds its con- 

 tinuation in the belt leading southeast from Mount Langum, above described 

 (see Marseilles moraine). The break opposite Mount Langum is merely 

 the width of the Kankakee Valley, scarcely 2 miles. 



No similar ridging occurs on the south side of the river in western 

 Kankakee or in Will County. There is instead a gradual rise from the low 

 bank of the river southward through a sand-covered district to the till plain 

 which lies inside the Marseilles moraine. The greater accumulation of drift 

 on the north side of the river, taken in connection with the occasional 

 development of moraine-hke features, apparently supports the interpretation 

 thus made — that the continuation of the Minooka till ridge may be found 

 along this line. 



BELIEF. 



The southern end of the well-defined Minooka Ridge (at the head of 

 the Illinois River) stands 100 to 110 feet above the Illinois River. The 

 general relief of this ridge above the plain which borders it on the west is 

 50 to 70 feet. The profile of the Chicago, Rock Island and Pacific Rail- 

 road, which crosses the ridge at Minooka, shows a relief od the west side 

 of about 65 feet. The relief is slightly less on the east and is also less 

 abrupt than on the west. 



The bluff-like ridge along the Kankakee, where best developed, stands 

 but 30 to 40 feet above the plains on the north, and its usual relief on that 

 side is only 10 to 20 feet. On the side next the Kankakee there is a gen- 

 eral relief of 30 feet or more, with occasional points where it exceeds 50 

 feet. Evidently a portion of this relief is due to stream erosion, but the 

 excavation is so shallow that the stream is responsible for scarcely 20 feet 

 of the relief. 



THICKNESS OP DRIFT. 



Beneath the crest of the Minooka Ridge, from the head of the Illinois 

 northward, the drift is shown by wells to be 130 to 150 feet and in one 



