328 the; Illinois glacial lobe. 



counties prevents a full and satisfactory correlation. But nothing to oppose 

 the correlation has yet been discovered. At present it seems necessary to 

 leave unsettled both its relation to the Iroquois moraine and to Minooka 

 Ridge. 



SECTION III. LAKE KANKAKEE. 



Nearlv thirty years ago Mr. F. H. Bradley applied the name Lake Kan- 

 kakee to a body of water which he thought formerly occupied a large part 

 of the Kankakee drainage basin. 1 The existence of a lake in this region was 

 suggested by the occurrence of deposits of sand outside the limits of the 

 present Kankakee marsh. Mr. Bradley recognized the influence of wind in 

 distributing sand over areas not covered by the lake, but considered the 

 evidence satisfactory that along the line of the Louisville, New Albany and 

 Chicago Railroad lake water had reached an elevation about 685 feet above 

 tide. He had not full opportunity to explore the region; hence his outline 

 of the extent of the lake is rather indefinite. 



Chamberlin touched briefly upon this sand area in his paper in the 



Third Annual Report, as follows: 2 



These dunes are a portion of a somewhat extensive tract, or perhaps rather a 

 series of tracts, in northwestern Indiana, the precise distribution and origin of which 

 are yet undetermined. They lie mainly in the Kankakee Basin, which was formerly 

 occupied by an extensive lake or lacustral river — "Old Lake Kaukakee" of Bradley — 

 and have been thought to be its shore accumulations; but their very wide extent and 

 great mass relative to the lake area, as well as certain features of their known distri- 

 bution, throw doubt upon the adequacy of this explanation. It would seem, from a 

 consideration of the glacial distribution of the second epoch, that this region must 

 have been the avenue of discharge of vast quantities of water, shed from the adjacent 

 slopes of the great glaciers occupying the basins of Lakes Michigan, Huron, and 

 western Erie. The great accumulations of sand probably had their ulterior origin in 

 this exceptional drainage, and were subsequently modified by lacustrine, fluvial, and 

 eeolian action. Their history is one of much interest, and its satisfactory determina- 

 tion can scarcely fail to reward industrious investigation when pursued in the light of 

 the glacial phenomena now under consideration, and may, in turn, cast reflex light 

 upon them. But however that may be, for the present, these dunes interpose an 

 element of uncertainty in the tracing of the moi-aine at what would, in any event, be 

 a critical portion of its course, for it is impossible to determine the character of the 

 drift which they conceal. 



The extent of the sand in the Kankakee Basin and in districts to the 

 south has been further investigated by Chamberlin since the above was 



I Geology of Illinois, Vol. IV, 1870, pp. 226-229. 



-Third Anoual Report, U. S. Geol. Survey, 1881-82, 1883, pp. 330-331. 



