MAIN MORAINIC SYSTEM OF THE SCIOTO LOBE. 401 



lobate tract east of the shoulder; (2) the portion of the moraine on the 

 shoulder; (3) the eastern limb of the main lobe; (4) the western limb of 

 the main lobe. 



INTEKLOBATE TRACT EAST OF THE SHOULDER. 



As the portion of this interlobate tract that lies north of the bend of 

 the Cuyahoga was being occupied by the ice sheet at the time when a 

 later series of moraines was forming, the discussion of its structure is 

 deferred, only the pc)rtion of the luoraine that lies between the bend of the 

 Cuyahoga, near Akron, and the glacial boundary at Canton being taken 

 up here. 



In the interlobate tract between the bend of the Cuyahoga and Canton 

 sections showing clayey till are rare,, the drift being of a very stony 

 character, not only in the knolls and ridges but in the lower tracts among 

 them. The stony drift is in places poorly assorted, and apparently represents 

 a slightly modified till from which the clayey ingredient is largely removed. 



In the Cuyahoga and Little Cuyahoga valleys there are extensive 

 exposures of an exceedingly fine silt or sand forming the main body of the 

 bluffs. It shows distinct lines of bedding, which are usually horizontal 

 but which arch slightly in places or exhibit signs of disturbance. A few 

 pebbles and very rarely a large stone niay be found embedded in the sand. 

 The silt is slightly calcareous, and contains in places nodules of carbonate 

 of lime and crystals of sulphate of lime. It is decidedly ferruginous, there 

 being in its u]3]jer or oxidized poi'tion numerous balls of iron oxide and 

 thin horizontal bands of iron following lines of bedding. The upper 10 to 

 15 feet, and occasionally as great a depth as 40 or 50 feet, is of a yellow 

 color, the tints of which are somewhat variable, depending upon the staining 

 by iron. At greater depth it is of a nearly uniform blue color, like the 

 ordinary blue till. Exposures of it 100 feet or more in height occur in the 

 northwest part of Akron, along the Valley Railway, and at numerous 

 points between Akron and Cleveland. Borings show a similar silt below 

 gravel at Summit Lake and Clinton, and at a deep well near Portage. The 

 gravel is connected on the north genetically as well as geographically with 

 moraines that cross the Cuyahoga below "the bend," and lead southward 

 across the present continental divide to the Tuscarawas Valley. The silt is 

 api^arently confined mainly to valleys and deeply filled lowland tracts, and 

 was probably deposited in a glacial lake. On uplands and where the drift 



MON XLI 26 



