658 TIIE GEOLOGY OF MINNESOTA. 



["Red till. 



The drift. Till. In the eastern part of the county, particularly in the 

 northeastern, the unmodified drift is red or copper-colored, and in the rest 

 of the county it is gray or bluish. In the eastern part of the county the un- 

 modified drift, or till, is not abundantly exposed, but is covered by a loam 

 of later date, and its character seems to blend rather more readily with the 

 loam than does that of the gray till. There is also an abundant dissemina- 

 tion of gravel derived from the gray till throughout the valleys in the north- 

 eastern part of the county. This gravel occupies the immediate surface in 

 some instances, only covered by a soil, but in others it is covered by a copi- 

 ous loam which often is rather sandy. This loam is sometimes ten or more 

 feet in thickness, and frequently is seen to be somewhat pebbly and appa- 

 rently to become mingled gradually with the upper portion of the under- 

 lying till, without the distinct intervention of the gray gravel. The most 

 westerly point at which this red till has been recognized is at the roadside 

 along the west side of section 9 in Cannon City, where it has been found to 

 contain pieces of native copper. It here presents its usual facies, viz., red- 

 dish color, rather sandy composition, numerous red and green pebbles and 

 stones of igneous origin and some red quartz-porphyry, referable to the 

 copper-bearing series of the northeastern part of the state, with rarely a 

 boulder or stone of gray granite, and more rarely still a piece of the foreign 

 drift-limestone. At this place the red till lies directly on the St. Peter 

 sandstone, but it is not everywhere present. It occupies, rather, the depres- 

 sions in the eroded upper surface of the St. Peter, and is covered by a gray 

 gravel which in numerous instances is itself deposited directly on the sand- 

 stone. Along the northwest quarter of sec. 9, Cannon City, the red till 

 rises higher and constitutes an upper timbered flat, rising about 1075 feet 

 above the sea. Here it lies on the Trenton limestone, and the bench which 

 it apparently produces, in passing westward to the river, is sixty feet in 

 hight. About half a mile still further west, lying on the St. Peter sand- 

 stone, is the great kame, or horse-back, as it is popularly known, running 

 through the bottoms of the Cannon river, and consisting wholly of gray 

 gravel. This red till seems to be the oldest part of the drift, and it is quite 

 probable that remnants of it will be found still farther west in sheltered 

 depressions in the St. Peter sandstone. Indeed, in the northeast part of 

 sec. 5, the road that ascends the hill northward from Carr's crossing, passes 



