132 PLEISTOCENE OF INDIANA AND MICHIGAN. 



North of the outlet of Twin Lakes, in sec. 18, T. 33 N., R. 1 E., a gravel knoll rises abruptly 

 about 100 feet above the level of the outlet. A gently undulating tract between Twin Lakes 

 outlet and Yellow River grades into an outwash apron. Some of the knolls bordering Lake 

 Maxinkuckee rise 75 feet above the lake and 30 to 50 feet above low tracts on the east. The 

 moraine is most prominent on the north and east sides of the lake. A few miles east of 

 Lake Maxinkuckee, just north of the village of Walnut, a small tract contains several knolls 30 

 to 40 feet high with interspersed basins and sloughs. The common topography, however, in 

 southern Marshall and northern Fulton counties is less sharply morainic, most of the swells 

 and ridges being but 10 to 25 feet high, and basins are uncommon. 



The weak outlying morainic belt in the southeastern part of Starke County has a few 

 knolls 25 to 30 feet high, interspersed with tracts of gentle undulation and broken for about 

 1£ miles midway of its length with a gap filled with sand ridges. Although weak when com- 

 pared with the Maxinkuckee moraine this moraine is in striking contrast to the bordering plains 

 on which there are no knolls. 



MAIN RIDGE SOUTH OF TIPPECANOE RIVEE. 



The undulating belt south of the Tippecanoe has few if any points exceeding 800 feet, 

 most of it being between 760 and 800 feet, and is relatively inconspicuous from either side. 

 Though its surface is decidedly more undulatory than that of the bordering plains, knolls exceed- 

 ing 25 feet in height are rare, the majority being but 10 to 15 feet. In the feeble outlying belt 

 south of the Tippecanoe the highest knolls reach about 20 feet and many are scarcely 10 feet 

 high. They are on the whole less conspicuous than the outlying sand ridges. 



In northern Cass and southern Fulton counties a bowldery belt lies in a plain as smooth 

 as that on either side, swells 10 feet in height being rare. Its altitude, however, is high, being 

 about 800 feet. For some miles it follows the divide between Eel River on the south and 

 Tippecanoe River on the north. From its northeastern end northward to Rochester the undu- 

 lation is greater, swells 10 to 20 feet high being common, and a sharp ridge in sees. 16 and 21, 

 T. 30 N., R. 3 E., reaches about 40 feet. 



INTEEMOEAINIC DISTRICT. 



In the district between the main ridge and the Bremen moraine swampy basins or depres- 

 sions are numerous, probably one-fourth of the surface being occupied by them. Most of the 

 dry land has a wavy or gently undulating surface. Most knolls are but 10 or 12 feet high 

 and few of them reach 20 feet. The features are such as might result from a rapidly receding 

 ice border. The most prominent ridge noted is one just west of Atwood, in western Kosciusko 

 County. It rises about 40 feet above surrounding country, is a mile in length, and nearly one- 

 half mile in width. A cut in its northeast end, made by the Pittsburgh, Fort Wayne & Chicago 

 Railway (Pennsylvania Railroad), is 25 feet in depth, and the roadbed of the railroad is raised 

 slightly to pass through it. 



STRUCTURE OF THE DRIFT. 



COMPOSITION. 



In the district north of the Tippecanoe, not only in the main moraine but in the gently 

 undulating tract east of it, the drift is largely of gravel and sand or of sandy till. The part 

 between South Bend and Potato Creek shows abrupt changes from gravel to till, knolls largely 

 composed of gravel standing next to knolls largely composed of till, and some single knolls 

 showing abrupt changes from gravel to till. The portion of the moraine between Potato and 

 Pine creeks is composed more largely of clayey till than any other equal-sized area north of 

 the Tippecanoe. From Pine Creek southward past Twin Lakes and Lake Maxinkuckee gravel 

 and sand are commonly found in knolls in, association with loose-textured till. East of Lake 

 Maxinkuckee some clayey till is found, but as a rule the drift is loose textured and more or less 

 gravelly. 



