208 GEOLOGY OF EASTERN WISCONSIN. 



to the formation an exceedingly irregular and complicated aspect. 

 It is apparently the equivalent of the Kames of Scotland, and Prof. 

 Geikie's graphic description is specifically applicable to our Kettle 

 Eange: 



"The sands and gravels have, as I have just said, a tendency to shape themselves 

 into mounds and wmding ridges, which give a linmmocky and rapidly undulating out- 

 line to the ground. Indeed, so characteristic is this appearance, that by it alone we are 

 often able to mark out the boundaries of the deposit with as much precision as we could 

 were all the vegetation and soU stripped away and the various subsoils laid bare. Oo- 

 cafiionally, ridges may be tracked continuously for several miles, running like great 

 artiBoial ramparts across the country. These vary in breadth and height, some of the 

 more conspicuous ones being upwards of four or five hundred feet broad at the base, and 

 sloping upwards at an angle of 25° or even 35° to a height of 60 feet and more, above 

 the general sm-face of the ground. It is most common, however, to find mounds and 

 ridges confusedly intermingled, crossing and recrossing each other at all angles, so as 

 to enclose deep hollows and pits between. Seen from some dominant point, such an 

 assemblage of kames, as they are called, looks hke a tumbled sea— the ground now 

 swelling iato long undulations, now rising suddenly into beautiful peaks and cones, and 

 anon curving up in sharp ridges that often wheel suddenly round so as to enclose a lake- 

 let of bright, clear water." 



The width of the Range is from one to ten miles, and its peaks oc- 

 casionally rise 300 feet above its base. 



Gravel, sand, bowlders and clay constitute the material of the Range, 

 and are variously intermingled in its composition. On the whole, 

 gravel is the most prominent element exposed to observation. It is 

 usually coarse but very irregular, and frequently full of rounded 

 bowlders. It is to be noticed that the cobble stones are spherieally 

 rounded and not flat, as is common in the beach gravel along Lake 

 Michigan. They are chieiiy composed of the magnesian limestone of 

 the region. T!ie sand is usually associated with the gravel, and it is 

 only occasionally that a deposit of pure sand, free from gravel or 

 bowlders, is foxmd. The clay is usually of a light color, moderately 

 tough, calcareous in composition, and contains imbedded in it erratics 

 of all sizes from those more than ten feet in maximum diameter down 

 to pebbles. Bowlders of Archaean rock are subordinate in numbers 

 to those of the Paleozoic formations, except where clustered in partic- 

 ular localities, as occasionally happens. But from the fact that no 

 Archsean formation is known to exist near the Range, the special dis- 

 tribution of this class of bowlders is of little importance. Quite the 

 contrary, however, with the limestone erratics, which are especially 

 demonstrative of its origin and formation. 



Near Burlington there is an exposure of a thin-bedded, rather 

 argillaceous dolomite, different from any seen elsewhere, and contain- 

 ing the Trilobite, Illwnus invperator, in considerable numbers, with 



