LATEE MORAINES OF LAKE MICHIGAN, SAGINAW, AND HURON-ERIE LOBES. 223 



In the great morainic mass which protrudes westward across Oceana County points within 

 a few miles of the shore of Lake Michigan stand as high as 1,000 feet and large areas stand above 

 800 feet, or more than 200 feet above Lake Michigan. 



The inner part of the morainic system is highest at the north a few miles south of Gaylord, 

 where it touches the 1,400-foot contour. It declines steadily southwestward and keeps above 

 the 1,300-foot contour to about the line of Antrim and Kalkaska counties, above the 1,200 to 

 about the latitude of Kalkaska, and above the 1,100 to the line of Kalkaska and Grand Traverse 

 counties. A few points in southern Grand Traverse County and on the moraine as far southwest 

 as the bend of the Manistee in eastern Manistee County reach 1,000 feet. South of Manistee 

 River most of the ridges on the inner border of this great system fall below 800 feet and p'art of 

 the surface below 700 feet. 



RELIEF. 



On the outer border of the system in the vicinity of Cadillac the ridges have a relief of 50 

 to 100 feet or more above an outwash plain which covers much of southeastern Wexford County. 

 The inner border relief of this portion of the system is 300 to 400 feet in Wexford County 

 and about 300 feet in eastern Lake and northeastern Newaygo counties. The great morainic 

 mass which runs westward from Newaygo County across Oceana County has a relief of 150 

 to 300 feet or more above the plains on its north and south borders. The slender moraines 

 running southward from Muskegon River have a relief generally less than 100 feet, dropping 

 to scarcely 50 feet as they near the head of the Lake Michigan basin : the inner or western moraines 

 have generally considerable relief, but the outer ones rise very little above the eastern outwash 

 plains. 



CHARACTER. 



The Lake Border morainic system has an exceptionally great variety of topographic 

 expression, for it comprises the great ridges formed by convergence of ice movement and con- 

 centration of material at the north end of the peninsula, as well as the weak ridges formed 

 where the ice was more free to spread out at the south end of the Lake Michigan basin. The rugged 

 northern portion not only shows great relief, but parts of it north of Muskegon River have 

 been cut by glacial drainage into an intricate network of prominent ridges and broad gravelly 

 flats. The outer part, however, in eastern Newaygo and Lake counties and southeastern 

 Wexford County is almost unbroken by drainage gaps. 



The ridges north of Muskegon River present a billowy surface with knolls 50 or even 100 

 feet in height, inclosing sags and basins. The ridges, which tend to parallel the trend of the 

 morainic belt, become successively lower toward the inner or western part of the system. 



The great morainic spur in Oceana and western Newaygo counties has a very billowy surface 

 and great irregularity in height independent of the numerous gaps made by glacial drainage in 

 the eastern part. The ice border seems to have shrunk across this morahhc spur from east to 

 west, and during the recession its escaping waters eroded the eastern part. 



In the district between White and Muskegon rivers evidence is preserved of the recession of 

 the ice border to the south of west. A billowy moraine leading southeastward from Hesperia 

 to Newaygo has an outwash apron on the northeast and a till plain on the southwest. In Mus- 

 kegon County this till plain includes a pitted gravel plain which is in places bowldery and seems 

 to mark a receding ice border. 



South from Muskegon River till ridges interrupted here and there by gaps in which sand 

 plains occur, bearing low swells and shallow basins on their gentle slopes, extend all the way 

 to the head of Lake Michigan. The basins and low plains were covered by the waters of Lake 

 Chicago after the ice had disappeared. 



