RICE COUNTY. (;(-,<, 



Kame. Minerals from the drift.] 



18. The Straight river continued to flow about where the kame lies, 

 after the withdrawal of the ice. 



19. When the upper Cannon valley was freed from the glacier, and it 

 received also the waters of the Minnesota, the volume of the river was so 

 great that it not only covered the kame itself but spread eastward over the 

 St. Peter sandstone. 



20. As the stony till lately deposited by the glacier was less easily 

 excavated than the St. Peter sandrock, gradually the greater volume of the 

 river ran over the strike of that sandrock; and this may have taken place 

 while only the Straight river occupied the valley, and perhaps when the 

 ice still existed in the interval between the old valley and the new one. 



21. Thus the river on the shrinkage again of the Cannon to its present 

 size, or on the withdrawal of the ice, was permanently diverted from its 

 course through or over the till deposits, marked by the present position of 

 the kame in sees. 33, 32, 29 and 21, and remained in the narrower, but 

 deeper, newly excavated gorge through which it flows from Carr's crossing 

 to where it returns to its old valley in the north part of sec. 27. 



22. A similar encroachment of the river on the St. Peter sandrock is 

 witnessed in sec. 19, in the north part of Paribault, where also the river has 

 abandoned its old valley, abundantly strewn with gravel, extending through 

 sees. 23, 13, and the west half of sec. 7, and has followed a recently excavated 

 narrow gorge through the St. Peter sandrock, a distance of about two miles, 

 uniting again with the gravel-strewn wide valley just below the Cannon 

 valley roller mill, S. E. cor. of sec. 8. 



23. After the formation of this kame there was no re-advance of the 

 ice over the same area. 



Minerals from the drift. Several pieces of native copper were found near the Cannon Valley 

 roller mill. S. E. } of sec. 8, Cannon City, some in excavating for the foundation of the mill, and 

 others along the road between sees. 8 and 0. They are from the red till which generally is there 

 found lying in the eroded depressions of the St. Peter sandstone. 



Several pieces of silicifled wood have been found at Northfleld. These evidently are refer- 

 able to the gravel and till of the gray drift derived from the northwestward. 



Among the specimens obtained from the drift, now in the collections of Carleton college, 

 Prof. Sperry has preserved a boulder of very coarse porphyry. The crystals are apparently of 

 albite, in a compact greenish diabase. They are about 1 \ inches in length, the corners and edges 

 somewhat rounded off, making the rock resemble a conglomerate. 



In the same collection of drift-stones are several pieces, about six inches long, of the felsite 

 of the Great Palisades, at lake Superior, with the disseminated crystals of quartz and translucent 

 feldspar. 



Small specimens of asbestus have been brought twice to Carleton college, once said to have 



