Artesian Well Boring in Southeastern Minnesota — Hall. 141 



VI r. The Mendota W Ehh"^'— Warren Upham. 



Formations 1, 2 and 3. Not present. 



4. Twenty-two feet in thickness. 



[This must be drift i.e. fallen pieces of the Trenton, as the well was bored at the edge 

 of the bluff, along which in many places large slabs of limestone are broken down. 

 Standing on the north side of the river, the Mississippi, the white St. Peter sandstone 

 can be seen to the eastward of the station at a higher level than the roofs of the buildings 

 — C. W. Hall] 



5. Consists of brown sand rock GO feet; blue shale 30 feet, and sand 

 rock 35 feet; total, 125 feet. 



6. 7 and 8. These thin formations are not here separated; total, 145 feet. 



9. A white sandstone 95 feet thick. 



10. A series of layers made up as follows: Gray shale, 50 feet; g-reeu 

 shale, 110 feet; limestone, 10 feet; blue shale, 30 feet. Total, 200 re<'t. 



11. This sandstone "at the top of the Saint Croi.x:** is 50 feet thick. 



12. As gray shale, 40 feet; green shale, 35 feet. Total, 75 feet. 



13. This does not appear. 



14. As a "very hard, red sandrock enclosing bed.s of shale.'' The 

 Potsdam was penetrated 145 feet. 



Total depth 857 feet. 



VIII. The 1Iastin(;s Wf.ll^-"'' -Warren Upham. 



Height, 700 feet above the sea. 



Formations 1, 2, 3, 4 and 5. Not represented. 



6. A thickness of 80 feet was passed. This doloniit*' is soen In the 

 >lreets of Hastings at a height considerably above the top of tliis well. 



7. Sandstone 15 feet in thickness. 



>^. A dolomite or dolomitic limestone 12 feet thick. [Wiuchell (h'sii^- 

 tiates this as a "dolomitic grit."] 



9. "Sand rock" 95 feet. 



10. "Shales; doiibtless also calcifirous sandstone." Colors, gray and 

 jicen; 213 feet. 



11. A sandstone containing pyrites. From the last 20 feet of this 

 formation came the lirst tiow of water; thickness 60 feet. 



12. This formation, while consisting chiefly of blue shalf (70 feet), 

 ( ontains also some green sand (20 feet), and dolomitic grit (5 feet). Total 

 thickness, 115 feet. 



13. A series of sandstones of varying coarseness, with sonic shale 

 towards the l)ottom, having a total thickness of 230 feet. 



14. From 820 feet down to the bottom of the well the rocks were 

 chiefly sandstones, but with some red shales; thickness of these beds 340 

 Icct. These are grouped by Upham as Potsdam. 



Depth of well, 1,160 feet. F'low of Avater 100 gallons j)er minute, whicli 

 reuches only a few feet above ground. The quality of this water is not 

 satisfactory for railroad uses. Note this Bulletin, p. 137. 



*N. H. Winchell has also copied Mr. Swan's notes. (Jeol. and Nat. Hist. Sur. Miiki., 

 I !th An. Rep., p. 55. 



'*"•■ ''' '' X. If. Winch'Ml, Geol. and Nat. Hist. Sur. Minn., i:5th An. Flep. p. ."O. 



