LATER MORAINES OF LAKE MICHIGAN", SAGINAW, AND HURON-ERIE LOBES, 255 



longer use than the part east toward Flint. The western part may be called the Ovid section 

 and the eastern part the Vernon section. The Vernon section is one-half to two-thirds of a mile 

 wide, and the Ovid section extending west from the Owosso esker trough is fully a mile wide at 

 all points. 



The explanation of this difference is perhaps to be found in the Owosso esker trough. Dur- 

 ing the building of the Owosso moraine a considerable part, though probably not all, of the river 

 turned out of the Owosso channel at Owosso and passed southwest through the esker trough 

 back to the Ovid section of the original channel, thus causing this part of the channel to be used 

 longer and made wider than the Vernon section. 



At its first flow the outlet river entered Genesee County through two or three distributary 

 channels passing near Eichfield and Davison, and formed a long, narrow lake, extending from 

 Kichfield southwestward to the vicinity of Dumeld. This may be called Kersley glacial lake, 

 after the principal creek that flows across its bottom. The outlet of this lake appears to have 

 been at first just north of Dufheld, but by erosion to have retreated eastward 2 or 3 miles. This 

 is the head of the Vernon section of the outlet channel and it was used only so long as the Kersley 

 glacial lake existed. 



With further retreat of the ice the river abandoned the Owosso channel and continued 

 northwest from Flint to Flushing, where it entered early Lake Saginaw. At this time it 

 entered Genesee County northeast of Richfield and flowed thence west past Genesee and Flint 

 to Flushing and appears to have flowed for a considerably longer time in this course than in any 

 of the earlier parts farther west. 



The distributaries near Richfield and Davison are very immature river channels and were 

 evidently occupied for only a short time. Northeast of Davison the southern distributary is 

 partly obstructed by three or four drift knolls which were standing as islands in the river when it 

 ceased to flow. They were apparently carved by the stream out of a morainic ridge. A large 

 distributary flowed west through northern Richfield Township and was joined in the western 

 part by another from the north. The northern distributary which flowed westward along the 

 present course of Flint River soon became dominant and determined the later course of the outlet 

 river and the present Flint River. The part of the channel extending from Lapeer County to 

 Flushing is considerably wider and more deeply trenched than the parts west of Flint. It also 

 developed more extensive valley gravels which now form terraces above Flint River. 



GRAND RIVER CHANNEL. 



GENERAL FEATURES. 



The Grand River channel is the largest and most deeply trenched glacial river channel in 

 Michigan and is one of the finest in the glaciated area of North America. The deeply trenched 

 part extends from a mile or more above the village of Maple Rapids to 5 or 6 miles southwest 

 of the city of Grand Rapids, a distance of about 75 miles. By later erosion the head retreated 

 about 16 miles farther east to the swampy divide north of Bannister. The part more particu- 

 larly described here extends from this divide to Saranac. The floor of the channel is 1 to l\ 

 miles wide and shows abundant evidence of having been scoured by a great river. Above Lyons, 

 where the modern Grand River enters, the channel is now occupied only by Maple River, a rela- 

 tively small, sluggish stream which is lost on the swampy floor throughout its whole course from 

 2 miles northwest of Bannister. The channel floor to Lyons is mostly a very stony, bowldery 

 old river bed, strongly indicating prolonged scour. Some few bars of gravel or sand that rise 10 

 to 12 feet above the swampy floor are distinctly due to the action of a great westward-flowing 

 river. 



In the lower part of its course between Lowell and Grand Rapids the channel is more deeply 

 depressed in the drift than toward its head. At some points its bottom lies more than 200 feet 

 below the country level a mile back, although the bluffs which form the immediate banks are in 

 few places over 120 feet high. Maple Rapids is on a terrace 25 to 30 feet above the channel floor, 

 but the general country level in that vicinity is 50 to 60 feet above the floor. Where the moraines 



