372 Artesian Wells in North and South Dakota, 



leaving only the Fort Benton shales or a part of that formation 



over the Dakota sandstone. 



At Devil's lake, where an artesian well was bored last year, 



about six feet above the depot, or 1,470 feet above the sea, the 



section was as follows : 



Section of zuell at Devil's Lake. 



Glacial drift, till as on the surface 25 feet. 



Dark shale, nearly alike through its whole thickness, 

 including the Fort Pierre and Fort Benton forma- 

 tions, with no noticeable calcareous beds at the 

 intermediate Niobrara horizon 1,403 feet. 



Gravel, of granitic pebbles up to a half inch in diam- 

 eter, firmly cemented with nodular pyrite 3 feet. 



Dakota sandstone, or rather a bed of lose sand, very 

 fine, white or light gray, the base of which was 

 not reached 80 feet. 



Total 1,51 1 feet. 



From the sandstone, at the depth of 1,470 feet, artesian 

 water came up with a rush, but sand soon filled the pipe so that 

 the supply became small. It is from this level that the present 

 flow comes, through narrow slits cut in the pipe. The boring was 

 continued forty feet deeper, but no such strong fiow was obtained 

 below. In July, 1889, when the well was completed, it supplied 

 1,800 barrels of water in 24 hours, or about 40 gallons per min- 

 ute, the diameter of the pipe being 8 inches, reduced to 33^ inches 

 in the lower portion. The stream flowing away was then turbid 

 with the exceedingly fine particles of sand brought up from the 

 bottom. 



The Jamestown well, bored in the winter of 1886-7, about 

 eight feet below the depot, or 1,400 above the sea, went through 

 a similar section of about 1,400 feet of shales, with no distinctly 

 different portion to indicate the place of the Niobrara formation. 

 The same nearly uniform section has also been found to a depth 

 of 1,350 feet at Deloraine in Manitoba, close northwest of the 

 Turtle mountain, as I am informed by Mr. J. B. Tyrrell, of the 

 Geological Survey of Canada. At that depth, which was bored 

 last year, there still lacked about 300 feet of reaching the sea 

 level, from which the Devil's lake artesian water rises. 



For the greater part of my notes of the artesian wells ot 

 South Dakota, also of Ellendale and Oakes, in North Dakota, I 

 am indebted to Resources of Dakota, published by the territorial 

 Commissioner of Immigration in 1887, and to recent correspond- 



