QUATERNARY FORMATIONS— THE DRIFT. 205 



group of islands, whose counterpart we now have in tlie chain that 

 stretches onward to the north. 



ol^ear North Bay the surface of the rock is beautifully striated 

 in a direction varying from S. 1° "W. to S. 13° E. These striae are 

 near the summit of a slightly elevated but nearly level area, and 

 present no indications of local modification. An inspection of 

 the more accurate maps shows many features in the outline of 

 the inlets and coast that harmonize with these south and south- 

 easterly groovings. The conclusion is forced upon the mind that 

 the inlets are glacial troughs, fiords, perhaps, we should call them, 

 though they were not formed by the descent of a glacier from 

 the interior of the peninsula toward the coast on either side, but by 

 the passage of the ice mass across the peninsula, forming the inden- 

 tations on the Green Bay side, in its ascent of the ridge, and those 

 on the Lake Michigan side in its descent. The charts of the U. S. 

 Lake Surveys show that, with this explanation, the term fiord is en- 

 tirely applicable. These troughs are continued far out under the 

 surface of the water. On the Lake Michigan side they reach from 

 twelve to fourteen miles at .least from the heads of their respective 

 bays. At from eight to ten miles out they show a tendency to curve 

 to the southward, i. e., to take a direction more nearly parallel to the 

 axis of the great depression in which the lake lies. Prof. IST. H. 

 Winchell has called attention to some of these features, and has asso- 

 ciated them in a very interesting way with the general glacial phe- 

 nomena of the region.^ I was not aware, however, at the time the 

 fiord-like characters first forced themselves upon my attention that he 

 had used the same term to characterize them. 



GLACIAL DRIFT. 



I. Moraines. 



1. Kettle Range. The term "Potash Kettle Eange" has been 

 popularly used to designate an extensive series of drift hills and 

 ridges in eastern Wisconsin, whose full extent and relationship were 

 unknown previous to the investigations of the present survey, and 

 concerning the true nature and origin of which, diverse opinions 

 have been held. As the term " Potash " has no special significance 

 in this connection, it will be discarded. The northern terminus of 

 the range lies in the town of Casco, Kewaunee county. Prom this 



' The Glacial Features of Green Bay of Lake Michigan, with some observations on a 

 probable former outlet of Lake Superior. Am. Jour, of Science and Arts, Vol. II, July, 

 1871, 



