bTEELE COUNTY. 3<)9 



Glacial drift.] 



19. Like No. 16 .............................. . 7 243 907 



20. Blue shale, arenaceous ....................... 3 250 900 



21. Blue shale ..................................... 8 253 897 



2-2. A cherty layer .................................. 1 261 889 



23. Hhte limestone ............................... 28 262 888 



24. White sandstone .............................. 80 290 860 



25. Similar to the last but very hard, thought to con- 



tain iron pyrites ........................... %.. 8 370 7SO 



26. White sandstone ............................. 9 378 772 



Total ..................................... 387 Bottom, 763 



These notes are discussed as follows by Mr. Upliam, in respect to the geological age of the 

 several parts of the section. 



The first thirty-nine feet are drift. 



The next fifty-nine feet, to a total depth of ninety-eight feet, appear to be Cretaceous de- 

 posits. Formations of this age, including thick beds of sandstone, occur in Blue Earth county 

 and farther west in this state, in northwestern Iowa, and in Dakota; but no massive sandstone, as 

 found in this well from the depth of sixty-three to ninety-eight feet, is known in any of the older 

 formations of this part of the continent till the horizon of the St. Peter sandstone is reached, 

 which surely underlies these and the next lower strata of this section. 



From 98 to 118 feet is undoubtedly the limestone before described, which outcrops beside 

 the Straight river within a few miles northward. In this well its hight above the sea is approxi- 

 mately 1030 to 1050 feet, its top being thus fifty feet, very nearly, lower than the quarries three 

 miles farther north, in Clinton Falls. This stratum thus dips to the south about sixteen feet per 

 mile. If the same dip continues through the eight miles northward from the Clinton Falls quar. 

 ries to the point near the center of Walcott township, in Rice county, where the Straight river 

 cuts through the Trenton limestone into the St. Peter sandstone, it would carry the horizon of 

 the limestone found at the depth 98 feet, or 1050 feet above the sea, in the Owatonna well, and at 

 about 1100 feet in Clinton Falls, to a hight 175 to 200 feet above the top of the St. Peter sand- 

 stone, which is 1040 feet, very nearly, above the sea, in Walcott and at Faribault. This consid- 

 eration. and the character of the beds penetrated in the next 144 feet at Owatonna, consisting 

 mostly of shale and clay, lead to the conclusion that these strata from 118 to 262 feet in the 

 Owatonna well, correspond to those which were penetrated, having a thickness of about 100 feet. 

 above the Lower Trenton limestone in the wejl at the State reform school, near St. Paul, as de- 

 scribed in the report of Ramsey county. 



The blue limestone, twenty-eight feet thick, next in the descending order, between 262 and 

 290 feet in depth, is quite certainly the Lower Trenton limestone; being the same formation that 

 occurs at Faribault, and at St. Paul, Fort Snelling and Minneapolis. 



The remaining ninety-seven feet to the bottom of this section are the St. Peter sandstone. 



drift. The drift in Steele county consists chiefly of till, or clay, 

 sand, pebbles and boulders, mingled in an unstratified deposit, of which 

 clay is the prevailing ingredient. It reaches from the surface to a depth 

 that varies in this county from fifty feet to probably a hundred feet or 

 more. The contour of this region is smoothly undulating and often nearly 

 flat, excepting two belts of knolly and hilly till, from one to several miles 

 in width, which extend from north to south, divided by a tract of gently 

 undulating till, from six to fifteen miles wide. These are moraines heaped 

 at the east border of the ice-sheet of the last glacial epoch, as terminal 

 moraines are formed at the end of alpine glaciers. A considerable retreat 



