Artesian Wells in North and South Dakota. 379 



through (i) drift, 298 feet; {2) limestone, apparently the Lower 

 Magnesian formation of the Cambrian series in southern Minne- 

 sota, 137 feet; (3) white sandstone, referred to the Jordan fonna- 

 tion of the same series, 65 feet, yielding a copious flow of brack- 

 ish water; (4) reddish, blue, and gray shales, with some arena- 

 ceous or cherty and dolomitic beds, representing the Saint Law- 

 rence formation of that series, 398 feet yielding a feeble flow of 

 very salt water from its upper part; (5) sandstone, perhaps a 

 trace of the Dresbach sandstone of southeastern Minnesota 5 feet, 

 yielding a small flow of brine, which was analyzed by Prof. Henry 

 Montgomery, of the University of North Dakota, and pronounced 

 more saline than sea water; and (6) granite, as determined by 

 Prof. N. S. Shaler from specimens of the borings, 12 feet. The 

 water used from this well is taken from the top of the Jordan 

 sandstone, at the depth of 438 feet. The diameter of the pipe is 

 six inches, and the flow, according to three measurements in 1886 

 and 1887, during the first year after the completion of the well, 

 was 800 gallons per minute. The reference of this section to the 

 Cambrian series seems to be well determined by correlation with 

 other wells penetrating Cambrian strata in this valley at Hum- 

 boldt, Minnesota, and Rosenfeld, Manitoba, respectively about 

 thirty-five and fifty-five miles farther north. At Rosenfeld, how- 

 ever, according to my interpretation of the section, the Cambrian 

 series is overlain by 352 feet of Lower Silurian strata, which there 

 are the bed-rocks first encountered below the drift. Not far west 

 of Rosenfeld and south of Grafton, the Dakota sandstone, form- 

 ing the base of the great Cretaceous series which is penetrated by 

 the wells at Deloraine, Devil's Lake and Jamestown probably 

 abuts, with horizontal or only slightly inclined stratification, upon 

 the similarly almost horizontally bedded Silurian and Cambrian 

 rocks. 



June 10, 1890. 



