IX INTKODlN'I'IoN. 



j>ointing north luid draiiiiiiLj south, which c.irrifti :i\v:iy the wat<.'r 

 from the nieltin<; ice, and at the same time depoKited vast })eds of 

 sand and gravel. The line of the discharge of tlie sand and gravel 

 between the Saginaw and Lake Jlioliigau l()l)eswas extended north- 

 ward as the ice melt^Hl hack, and passeid fr«»in near Kalamazoo up 

 to the City uf Grand ]la)»id8, r.nd ihciice north-east and north up 

 hey end (Tray ling."' 



In the process of ineltiiig away, the ic(! front sctMiiM t<i have 

 made stops or halts. ''I'^he succesaive halts of the ice front are 

 marked by massive ridges comjtosed of till, or stony day, boulders, 

 gravel, and sand, which are called moraines. These sweep around 

 Saginaw Bay, and connect on the west with ridges tiuit pass 

 southward or southwestward toward the head of Lake Michigan, 

 and on the east with ridges that lead southwestward from the 

 Thumb (between Saginaw Bay and Lake Huron) across the south- 

 eastern part of Michigan and northwestern corner of Ohio into 

 Indiana. The position of these morainic ridges has been only 

 partly worked out, and their mapping is now in progress. Dr. Lane 

 and his assistants of the State Survey have covered part of the 

 State, while Messrs. Leverett and Ta3'^lor of the United States Sur- 

 vey have recently cooperated with Dr. Lane to complete the map- 

 ping. The following upon the glacial drift and surface features 

 of this vicinity has been contributed by Mr. Leverett who has ex- 

 amined the region around Grand Rapids: 



■•The features are somewhat intricate but they fall in naturally 

 with the view that there was a jtmction of two lobes in this vicin- 

 ity. When the ice extended nearly to the southern border of 

 Michigan, the junction between the Saginaw and Lake Michigan 

 lobes was in a great belt of gravel that is traversed by the Grand 

 Rapids and Indiana Railroad south from Kalamazoo, and the point 

 <>f the reentrant angle was in the great ridges south-east of Gun 

 Lake. 



"From this position the ice melted back until the point of the 

 reentrant anerle between the ice lolx^s was at the Dias Hills, a few 



