216 GEOLOGY OF EASTERN WISCONSIN. 



JSTear the western extremity, there is a conspicuous north and south 

 drift range, over which the minor ridge under consideration passes; 

 and in doing so, it curves to the northward in a very peculiar manner. 

 Throughout sections 5 and 6, the ridge lies upon an elevated table- 

 land or plateau formed of drift material. To the east of this it grad- 

 ually curves to the northeastward and descends to a considerably 

 lower level, the eastern extremity being very much lower than the 

 western. The two peculiarities worthy of special notice are the fact 

 that it is a drift ridge, superposed upon an evidently earlier drift for- 

 mation, to whose surface coniiguration it conforms in a measure, and 

 the fact that its elevation is markedly diiferent in different portions. 

 These facts are sufficient to show of themselves that it could not be 

 formed by the action of water, since no supposable warping of the 

 earth could bring it into such a position as to constitute the margin of 

 a lake or other body of water supposed to be capable of forming such 

 a ridge, and for the same reason its origin cannot be attributed to 

 floating ice. In addition to these facts, its structure and the material 

 of which it is composed, forbid such a supposition. It is composed 

 of confusedly intermingled coarse and fine unstratified material. A 

 large number of bowlders of various classes of rocks — Paleozoic and 

 Archaean — - are imbedded in sand, gravel, and clay, in most promiscu 

 ous confusion, and in some cases in such a position as would forbid 

 the supposition that they were deposited upon the surface of a grad- 

 ually accumulating mass. In one 

 instance a mass of finely laminated 

 clay, apparently a clay bowlder, 

 was found surrounded by the com- 

 mingled unstratified material. The 

 accompanying figure illustrates the 

 Section of mobainb ix Town of hebhan. gg^eral nature of the Structure of 



the ridge. It is apparently due to a local advance of the thinned 

 edge of the glacier upon the surface of drift already deposited, roll- 

 ing up the ridge in front of it. It will be evident that such an ad- 

 vance would be retarded by the north and south ridge in section 6, if 

 the thickness of ice were inconsiderable, and at the same time its 

 melting hastened, which accounts for the peculiar fiexure of the mo- 

 raine in crossing it. 



A similar chain of hills and ridges occurs in sections 16, 21 and 27 

 in the town of Beloit. The base of the chain at its eastern extremity 

 has an elevation of about 200 feet above Lake Michigan. As it ex- 

 tends northwestward, the surface upon which it rests rises until the 

 moraine rests upon the crest of a rock ridge, at least 250 feet in 



