246 



PLEISTOCENE OF INDIANA AND MICHIGAN. 



The altitudes given below for the general crest level of the moraines are based on scattered 

 measurements, mostly by aneroid barometer, and are not those of the highest knobs. The 

 values stated are therefore not precise but rather general in quality. 



Altitudes on moraines of deployed belt. 



a Overridden east of Lansing. 6 Water-laid. 



Water-laid moraines in general have somewhat less relief than land-laid forms. Some of 

 them may also have been more or less reduced in altitude by wave erosion. The uncertainty 

 of their identity east of Flint River gives no chance for certain determination of their altitudes 

 at the meridian of the west line of Lapeer County nor of the amount of rise. The confusion of 

 the overridden moraines east of Lansing also leaves in doubt the altitude and amount of rise 

 of the individuals in that area. 



The altitude of the moraines along the axial line through the successive positions of the apex 

 are of course dependent mainly on the character of the ground over which the ice lobe advanced. 

 From 875 or 880 feet altitude at the apexes on the Lansing and Grand Ledge moraines the 

 altitude drops about 200 feet to the Chesaning moraine, but the greater part of the drop is in 

 the later water-laid moraines which pass below the former lake level. The lower relief of the 

 moraines deposited at the edge of the ice where it stood in lake water contributes something 

 to this difference. A north-and-south hue through Owosso crosses all the moraines except the 

 Lansing. The distance is shorter than on the axis and the difference of altitude is a little greater, 

 for the general level of the overriding moraine 5 miles east of Lansing is a little above 900 feet. 



The axis of the Flint Valley protrusion was about on a line running northwest and southeast 

 through the city of Fhnt, and the altitude of two or three of the moraines preceding the Flint 

 is slightly lower near this axis than to the southwest or the northeast. The St. Johns moraine, 

 for example, has a general crest altitude of 875 to 880 feet in the northern part of T. 5 N., R. 5 E. 

 (Argentine Township), and of only about 780 feet in the northwestern part of T. 7 N., R. 8 E. 

 (Davison Township). A lake stood in front of the ice at this stage with its outlet 3 miles north 

 of Linden at an altitude of about 850 feet. Then from the relatively low axis of the Flint 

 sublobe all the moraines rise toward the high morainic area of southern Tuscola County. 

 North of Otter Lake an altitude, of over 900 feet is reached on the Otisville moraine. 



The relief of the moraines of this group is generally low, averaging about 20 feet above the 

 plain in front of them and generally somewhat less above that behind them. Their relief, 

 however, in much of their course is considerably less than this, and in some intervals, as from 

 Riley eastward in Chnton County and in southern Gratiot County, it is entirely absent. The 

 water-laid fragments are mostly without noticeable relief. 



Where the moraines are developed as distinct individuals without overlapping no point 

 was found with a height of more than 60 feet above the plain and few points above 45 or 50 feet. 



In the region of overriding the relief becomes greater, in not a few places reaching 80 or 

 90 feet, and in some reaching more than 100 feet. This applies especially to the belt east of 



