252 THE GEOLOGY OF MINNESOTA. 



[Shakopee limestone. 



were once capped by the Trenton limestone, as in the adjoining high-lands, 

 and their demolition under natural causes has not proceeded far enough to 

 bring them down to the level of the lower prairies, but seems to have quite 

 destroyed the overlying limestone. 



The Shakopee limestone. The best exposure of the Shakopee limestone, 

 within the county occurs at Troy, in Saratoga township. It there presents 

 a thickness of twenty-five feet, along the creek on each side of the dam, and 

 has been quarried for use in the construction of the Troy flouring mill. It 

 has the color and most of the usual lithological characters of the St. Law- 

 rence'as seen in Winona county. The Jordan sandstone is visible at the 

 same place immediately below it, and the St. Peter at higher levels in the 

 neighboring bluffs. Further down the creek, in Fillmore county, the St 

 Lawrence limestone forms a continuous exposure with a thickness much 

 greater. The Shakopee limestone appears at St. Charles, along the creek, 

 and also in the streets of the city, with a dip toward the S. S. W., coinciding 

 with that already mentioned in the St. Peter near the same place.* It is 

 visible at the Quincy mills, where it overlies the Jordan sandstone. f In the 

 central and eastern parts of the county this limestone is seldom seen, and 

 when observed it is under unfavorable circumstances. It can only be said 

 of it that it exists as far east as Stockton, and probably as far as Homer and 

 Dresbach on the Mississippi. 



The presence of the Shakopee limestone in the highest lands in the north part of Homer is 

 indicated by the occasional occurrence of "sink-holes" which it causes in the loam-covered surface 

 in connection with the Jordan sandstone. 



Above Brown's quarry at Dresbach, which is in the St. Lawrence, near the top of the bluff, 

 is a debris in the upper slopes that seems to contain both the Jordan and the Shakopee, but nothing 

 can be seen in place of either of them. It is visible in the road between sections 4 and 5, Utica. 



It is seen to overlie the Jordan sandstone on the road between sections 13, Utica, and 18, 

 Warren, south of the railroad. 



It is occasionally seen in section 30, Fremont, and between sections 32 and 33, Utica. 



In general, however, as the county is occupied very largely by the area of the broad Cam- 

 brian anticlinal, the Shakopee has suffered by erosive agents, and this only may be the cause of 

 its non-appearance in the Mississippi bluffs. In the same manner the St. Lawrence is reduced in 

 thickness on this anticlinal when it is at the surface. 



The Jordan sandstone. This sandstone, which overlies the St. Lawrence 

 limestone quarried at Stockton and Winona, is finely exposed near the 

 Stockton quarries along the railroad, a mile and a half east of Lewiston, 

 S. W.J sec. 18, Warren. It is also visible by the highway along the east and 



*A similar'dip is mentioned ]in the report on Houston county, in the St. Croix sandstone, at Sheldon. 

 tSee the report on Olmsted county. 



