144 PLEISTOCENE OF INDIANA AND MICHIGAN. 



corner of Cass County, Mich., and continues west-northwestward for about 12 miles to the 

 valley of Christian Creek, about 5 miles southeast of Cassopolis, west of which it disappears, 

 giving place to an outwash apron from the Kalamazoo morainic system of the Lake Michigan 

 lobe. 



Southwest from Lagrange what appears to be the Huron-Erie equivalent of the Lagrange 

 moraine is distinctly developed in the district between Lagrange and Elkhart River. It leads 

 southwestward from Lagrange to Ligonier, passing just east of Topeka, and bears away south- 

 eastward to Albion, where it merges with the great moraine of the Huron-Erie lobe. (See 

 p. 158.) 



The Lagrange moraine is about 3 miles wide, though somewhat broader at its northwestern 

 end. The correlated moraine in the Huron-Erie lobe is 2 to 3 miles wide. 



TOPOGRAPHY. 



In its greater part the moraine rises above 900 feet and at a few points it exceeds 1,000 

 feet; much of it reaches between 900 and 950 feet. One elevation of about 1,000 feet is a 

 knob in the northeast corner of Elkhart County, Ind., on the line of sees. 13 and 24, T. 38 N., 

 R. 7 E. ; another is the knoll bearing the Calvin geodetic station, in southern Cass County, Mich., 

 whose altitude is 1,011 feet; a third is a ridge east of Lagrange in sees. 14, 15, 22, 23, 26, 27, 

 T. 37 N., R. 10 E. In Indiana the relief above the outer border district is very slight, averaging 

 scarcely 20 feet; above the inner border it is much greater, because of the Pigeon Valley depres- 

 sion. It is least near Lagrange, where it is fully 75 feet, increasing westward to more than 100 

 feet. In Michigan the relief above the outer border is only 25 to 50 feet except in a small 

 district around the Calvin geodetic station, where it exceeds 100 feet. The relief on the inner 

 border is somewhat less than it is on the outer. 



The Indiana portion of the Lagrange moraine contains numerous small steep-sided knolls, 

 among which are marshes and gently undulating till tracts. Several square miles in the north- 

 west part of Lagrange County and the northeast part of Elkhart County have sharp knob and 

 basin topography, in which knobs 40 to 60 feet high inclose tamarack swamps and small lakes 

 without outlet. East of Lagrange a prominent ridge in sees. 10, 11, 14, 15, 22, 23, 26, and 27, 

 T. 37 N., R. 10 E., stands 50 to 75 feet or more above a plain east of it and 25 to 50 feet above 

 the bordering moraine on the west. 



The portion in Michigan sets in near the State line with sharp knolls between Baldwins 

 Lake and Long Lake. A fosse or depression, 20 to 30 feet below the gravel plain south of it 

 and one-eighth to one-fourth mile wide, is present along much of the outer border from Long 

 Lake to Christian Creek. The main ridge lies 1 to 2 miles or more back from the southern 

 edge of the moraine, and diverges from it somewhat, trending slightly north of east across Calvin 

 Township from sec. 30 to sec. 24, whereas the south border of the moraine trends south of east 

 from sec. 31, Calvin Township, to Long Lake in sec. 9, Union Township. The district between 

 the fosse and the main ridge is gently undulating and is thickly strewn with bowlders. The 

 main ridge bears a chain of sharp gravelly knolls, which rise 50 feet or more above the general 

 level; it is on one of these that the Calvin geodetic station was placed. North of the main 

 ridge a chain of lakes leads from sees. 13 and 24 westward to Christian Creek. They are bor- 

 dered closely by sharp knolls and ridges and have no broad outlets nor connecting strips of 

 lowland. North of the chain of lakes in sees. 10, 11, 13, 14, 15, and 16, Calvin Township, is a 

 gently undulating tract thickly strewn with bowlders which gives place farther north and west 

 to a gravelly plain. The portion in Cass County, Mich., seems to have been formed in a reen- 

 trant between the Lake Michigan and Saginaw lobes. The strong ridge on which the Calvin 

 geodetic station stood has the trend natural to the Lake Michigan lobe. 



STRUCTURE OF THE DRIFT. 



Most of the sharp knolls are composed of gravel even where the surface of the gently undu- 

 lating moraine around them is clayey till. The knob and basin tracts are composed of gravel, 

 cobblestones, and bowlders, with only a small amount of till or assorted material. Bowlders 



