148 PLEISTOCENE OF INDIANA AND MICHIGAN. 



The outer border plain or outwash apron, where not trenched by later glacial drainage, 

 stands nearly as high as the moraine. Its greatest height, 1,000 to 1,010 feet, is in northeastern 

 Lagrange County, Ind., and it shows a steady decline to the westward along the edge of the 

 moraine, being 935 at Sturgis, 890 opposite Klinger Lake, and 820 feet near White Pigeon. 

 Its height, in the portion west of St. Joseph River near Fabius, on the outwash from the Saginaw 

 part of the interlobate tract, is about 900 feet ; on the outwash apron east of the moraine of the 

 Lake Michigan lobe in sec. 34, Flowerfield Township, St. Joseph County, it is also about 900 

 feet. 



The general relief of the moraine above the outwash aprons in the district west of St. 

 Joseph River is only 30 to 50 feet, though as above indicated the highest knolls are about 200 

 feet higher. In the district southeast of the St. Joseph the relief is not generally more than 

 30 feet, but the knolls near the Sherman geodetic station reach about 100 feet above the neigh- 

 boring part of the outwash apron. 



On part of the inner border of the mam portion of the moraine the gravel plain is somewhat 

 lower than it is on the outer border which sweeps around the island-like tracts of moraine above 

 noted. Its altitude near Centerville is 820 to 830 feet, but it rises southeastward to about 

 875 feet near Burr Oak. The adjacent parts of the moraine are 75 to 100 feet higher than the 

 plain. The island-like tracts rise 25 to 100 feet above the plain, the most prominent being 

 "Colon Mountain" just south of Fairfax station, which rises fully 100 feet above the border- 

 ing plain, or about 950 feet above sea level. The narrow strips of gravel plain between the 

 morainic ridges southeast from Sturgis are somewhat lower than the outwash apron outside 

 and become lower and lower from south to north. The inner slopes of these ridges consequently 

 show more relief than the outer ones. 



CHARACTER. 



The topography of the main part of the moraine is largely of the knob and basin type, 

 most of the knolls have steep slopes. The portion near Sturgis and westward to Centerville 

 is so rough that many steep grades are necessary on the Grand Rapids & Indiana Railway 

 and on the numerous wagon roads that cross it. The railroad profile shows altitudes ranging 

 from 877 to 957 feet within the limits of the moraine; barometric readings along a north-south 

 road from Centerville across the moraine, taken by Cooper, show a range from 823 to 942 feet 

 between the lowest basins and the highest ridges or knolls crossed by it; the main road east 

 from Sturgis across the moraine shows a range from 895 up to 954 feet, the altitude of the 

 edge of the outer border plain being 937 feet. 



Numerous basins in the midst of the moraine from the meridian of Sherman westward 

 to the gravel plain of St. Joseph River are much lower than the outwash apron south of the 

 moraine. Klingers Lake and the chain of lakes east of it have a water surface 50 to 60 feet 

 lower and beds in jilaces fully 100 feet lower than the part of the outwash apron immediately 

 south of them. The surface in this part of the moraine thus ranges from about 100 feet above 

 (at the Sherman geodetic station) to 100 feet below the outwash apron. 



Southeast from Sturgis the moraine shows less roughness of topography than it does 

 northwest of that place, much of the surface between ridges being graded up with gravel and 

 sand to a plain. The outer ridge is practically continuous for about 14 miles from Sturgis 

 to a point within 2 miles of Orland and yet in places is less than one-fourth mile wide and 

 scarcely anywhere is a mile wide. The ridges back of it are interrupted by many gaps and 

 more than half its surface is occupied by sandy plains. 



Most of the knolls north of the main ridge near Centerville and east of Wasepi are small, 

 but a few are 50 feet high, and, as above noted, Colon Mountain stands 100 feet above the 

 bordering plains. 



The district north of Mendon is similar to the knolly tracts, except that it fades gradually 

 into a till plain toward the northeast. 



In western Branch County the inner part of the Sturgis moraine is characterized by strips 

 of sharply undulating or ridged drift alternating with nearly plane strips, all trending northeast 



