278 PLEISTOCENE OF INDIANA AND MICHIGAN. 



BUTTERNUT CHANNEL. 



The Butternut channel came in from the northeast as a tributary to the Imlay channel. 

 It ran southwest along the front of the Owosso moraine and had its headwaters apparently in 

 the vicinity of Kingston and East Dayton. In its length of about 25 miles the present channel 

 descends 140 feet — from about 880 to 740 feet. Its course was directly down the plain of 

 the tilted land, so that something like 30 feet must be subtracted to find its original descent of 

 100 to 110 feet. At its head it drained two or three small lakes, one lying southwest of Kingston 

 and others, probably smaller, in Koylton Township and northeast of Mayville. 



In the lower course of the Butternut channel, from a point about west of Otisville, promi- 

 nent gravel terraces, like those of the Imlay channel, suggest a certain amount of aggradation or 

 filli n g after the first or most active deepening. This and the strongly marked aggradation of 

 the Imlay channel between Columbiaville and Flint are probably associated with a readvance 

 of the ice front in Genesee County. 



EAST DAYTON SPILLWAY. 



Although the Juniata moraine is poorly developed except in two or three places, the ice 

 front while building it appears to have formed the northern bank of a large river, known as 

 the East Dayton spillway, which flowed toward the southwest in southern Tuscola County. 

 Its course where it is constricted 2 or 3 miles west of East Dayton is well defined. Its present 

 altitude at this point is about 740 feet. At an earlier stage it probably flowed at a level 30 or 40 

 feet higher and passed through central Fremont Township to the sandy area near Juniata. 



Through Wells and Novesta townships the bowldery belt probably marks the fine of its 

 flow at the lower level. The part of the belt which comes from the southeast in Novesta Town- 

 ship is in all probability due to the scour of the stream without the aid of the ice front in contrib- 

 uting bowlders. The bowlder belt heads near Novesta, and the two arms of the long swamp 

 of the south branch of Cass River end there. The altitude is now 775 to 780 feet and was orig r 

 inally 80 or 85 feet lower. 



The flow of the East Dayton spillway was certainly very short lived as compared with the 

 Imlay outlet river. The river was probably temporary and existed only during a brief halt 

 in a relatively rapid retreat of the ice front in the transition from Lake Maumee to Lake Arkona. 

 The spillway appears to head on the till plain of Sanilac County and is not known to be related 

 to any beach. 



NORTH BRANCH TRANSVERSE CHANNEL. 



From the extreme northeast corner of Burnside Township, Lapeer County, a well-developed 

 channel, known as the North Branch transverse channel, runs southwest and west to the Imlay 

 channel, a mile above North Branch. It is a swampy depression of varying width down to a 

 point about 5 miles east of North Branch, beyond which it is floored with gravel. The gravel- 

 floored part is one-third to one-half mile wide and the bordering land rises 20 to 40 feet, but not 

 steeply. 



LAMOTTE CHANNEL. 



The channel associated with the Lamotte esker is closely related to the North Branch trans- 

 verse channel. From the northeast corner of Lapeer County the Lamotte swamp runs directly 

 north along the south branch of Cass River, expanding within 3 miles to a width of 2 miles. 

 For 6 miles farther north it contains the broken chain of the Lamotte esker. Two miles still 

 farther north it divides into two branches of irregular width, both of which bear northwest to 

 a point near Novesta, where they meet the east end of the bowldery belt that marks the East 

 Dayton spillway. 



The Lamotte channel was made originally by a southward-flowing subglacial stream or one 

 flowing in an ice-walled canyon in the thin mass of dead ice which appears to have covered the till 

 plain of Sanilac County at that time. The ice front then rested about on the Deanville and May- 

 ville moraines, and the part of the channel which lay outside of the ice front (now constituting 



