228 Wisconsi7i Academy of Sciences, Arts, and Letters. 



Origin. — Waiving, for the present, some further generalizations, 

 it is thought that the foregoing phenomena present a specific com- 

 bination which points unequivocally to a morainic origin. To the 

 writer, familiar with the multitudinous details, that cannot here 

 find a place, and having studied recent moraines with special refer- 

 ence' to this formation, they have a force little less then demon- 

 strative. The range is confidently regarded as a moraine formed 

 at the margin of a group of glaciers — which may be regarded as 

 a single lobate one — and marking a definite stage of their history, 

 A more vivid and graphic view of the outline and movements of 

 these glaciers, than can be given in words, may be obtained from 

 the accompanying map, from which it will appear that through 

 each of the great lake troughs there poured an ice stream, at- 

 tended by minor currents through the lesser channels. 



Its Medial Position. — It has already been remarked that, in the 

 interior, this moraine does not mark the extreme limit of glacial 

 advance. N^umerous striations, and other evidences of glaciation, 

 occur on the south side of it. A line has been drawn on the map 

 intended to indicate the approximate limit of northern drift, based 

 on several authorities.^ How nearly this shows the limit of actual 

 glacial progress, in distinction from other means of transportation, is 

 not, I think, as yet definitely ascertained, but the general fact of 

 progress, to a considerable distance beyond the Kettle moraine, is 

 sufficiently established. The moraine was, therefore, formed after 

 the retreat of the glacier had commenced, and marks a certain stage of 

 its subsequent history. 



Glacial Movements hefore the Formation of the Moraine. — It be- 

 comes an interesting question to ascertain whether the glacial 

 movements were the same before the formation of the moraine, as 

 afterwards. Fortunately, in southern Wisconsin, we have v ery 

 definite and specific evidence bearing on this question. In the 

 towns of Portland and Waterloo, which lie within the area of 

 the Green Bay glacier, and from twenty-five to thirty miles distant 

 from the moraine, there are several domes of quartzite that rise 

 through the horizontal sandstones and limestones, which occupy 

 the surrounding region. These domes are glacially abraded and 

 grooved in a direction S. 30° W., and trains of quartzite boulders 



» Tesley, Newberry, Cox, and assietantB, Worthen, Swallow, and Mndge. 



