LATER MORAINES OF LAKE MICHIGAN, SAGINAW, AND HURON-ERIE LOBES. 251 



large volume and in some parts suggesting longer duration. Of the former class are the Holly, 

 which is the largest, the Lookingglass, the Bennington, and the Butternut channels. Of the 

 latter class are the Imlay channel, with several branches in its western part, and the Grand 

 River channel, which is of truly great capacity and relatively mature development. 



Besides these in which the connections and relations are clear, there are one or two frag- 

 ments of channels which are isolated and the connections of which are problematic. Of this 

 class is the Lansing channel, which is as large or larger than the Holly channel. 



While the ice front was retreating across this district and building the slender moraines of 

 the deployed group the amount of sandy and gravelly outwash shed from the front of the ice 

 or brought out by streams issuing from it was relatively small; indeed, in comparison with that 

 which issued from the front of some of the bulkier moraines, it seems extremely small. This, 

 perhaps, is due to a lack of concentration; if all the slender moraines were compacted into one 

 mass and all the outwash concentrated on one line the discrepance might not seem so great. 



DRAINAGE SOUTH OF IMLAY CHANNEL. 



DISTRIBUTION. 



During the formation of the Lansing moraine all the drainage along its front west of Lansing 

 appears to have been directly away from the ice, mainly along the courses of several creeks 

 which flowed southwest. The valleys of the creeks show in some places gravelly terraces or 

 remnants of valley gravels that seem to belong to the time when the ice was present. The 

 creeks occur at intervals of 3 to 4 miles, and most of them, such as Sebewa Creek, Mud Creek, 

 and three or four branches of Coldwater Creek seem to have issued directly from the ice. 

 Streams appear to have issued along the same lines during the building of the Grand Ledge 

 moraine. As a result, they begin at the Grand Ledge moraine and run southwestward directly 

 through the Lansing moraine. 



LANSING CHANNEL. 



Along most of its front the Lansing moraine shows no evidence of concentrated drainage 

 or of readvance of the ice, but at Lansing it furnishes a striking example of readvance, closing 

 a large channel of ice-border drainage which had been made just before, when the ice front 

 stood a little farther to the north. From the vicinity of East Lansing, a flat valley one-half 

 to three-fourths mile broad, distinctly depressed below the surrounding till plain and floored 

 with sand and gravel, extends westward to the south part of Lansing and on for about 1-J miles 

 up Grand River to the Logan Street Bridge. This part of the old drainage channel was not 

 overridden at the time of the Lansing moraine. In this old channel Cedar River wanders in 

 many meanders, generally with a sluggish current, and Grand River has wide room to spare. 

 But at the Logan Street Bridge Grand River is suddenly shut in between walls of bowlder clay 

 30 to 40 feet high and the channel is so narrow that it has no well-defined flood plain. A dam 

 a quarter of a mile below now backs the water up into the narrow part. The banks are steep 

 and the topography of the drift on both sides of the river for about 3 miles to the southwest is 

 distinctly morainic and is in fact a part of the Lansing moraine. The old drainage channel was 

 evidently overridden and completely filled up for some distance west of Lansing. 



A large channel of glacial drainage runs northwest from the bend of Grand River at Dia- 

 mondale, as shown on the Lansing topographic sheet, and expands into a swamp close in front 

 of the Lansing moraine. The Diamondale channel turns a right angle in this swamp and passes 

 westward down Thornapple River. It may be that the buried Lansing channel formerly 

 extended westward and joined the Thornapple channel at this place in the southwest corner of 

 T. 4 N., R. 3 W. (Delta Township). The features suggest this relation, but no certain proof 

 was found. 



East of East Lansing the old channel seems to branch, one part coming down Cedar River 

 from Okemos and the other from Pine Lake across the northwestern part of T. 4 N., R. 1 W. 

 (Meridian Township). This is well within the region of the overlapping moraines, where the 

 relations are complicated. The drainage along the front of this belt mil be described later (p. 253). 



