SOUECES OF SALT IN ARTESIAN WELLS, 535 



there rises more than SOO feet in a distance of 106 miles from west to east. 

 It appears thus to be the V)ed rock, on which the drift is deposited, beneath 

 extensive tracts in tlie middle part and on the western border of the Red 

 River Valley, dischargnng- there its alkaline and saline artesian water into 

 the permeable beds of gravel and sand in the drift sheet, whence it rises in 

 the brackish wells of that district. 



Relationship to artesian ivells at Totver City and Grafton, N. Dak, Hum- 

 hoJdt, Minn., and Morden {not artesian) and Rosenfeld, Manitoba. — An artesian 

 well at Tower City, 50 miles east of Jamestown, is 4 feet lower than the 

 depot, being- 1,1(38 feet above the sea. Its depth is 670 feet, through ch-ift, 

 163 feet; Cretaceous shales, with occasional beds of sandstone, 502 feet; 

 and quicksand, into which the boring advanced only 5 feet. Salty and 

 alkaline water outflows 9i gallons per minute, and is capable of rising 33 

 feet above the surface. The scanty flow and low liead of this well suggest 

 that the water-bearing stratum may be inclosed within the Fort Benton 

 shales ; but its altitude, 500 feet above the sea-level, accords with that of the 

 sandstone reached by wells at Blanchard and Mayville, so that more prob- 

 ably it is the top of the Dakota formation. The plane of the head of water 

 supplied from this formation would show a marked descent northeastward, 

 as is thus indicated at Tower City, still more distinctly at Morden (page 

 81), and in less degree at Devils Lake, in comparison with Jamestown 

 and Ellendale, if there are abundant natural outlets of this artesian water 

 along the Red River Valley, as appears to be true, by springs rising through 

 the drift. These brackish springs occur on many of the streams tributary 

 to the Red River both in North Dakota and Minnesota, the most remark- 

 able being on Forest and Park rivers, which therefore were formerly called 

 the Big and Little Salt rivers.^ 



Beneath the central part and western side of the Red River Valley, 

 the Dakota sandstone, forming the base of the great Cretaceous series which 

 is penetrated ])y tlie wells at Deloraine, Devils Lake, and Jamestown, 

 probably abuts in many places, with horizontal or oidy slightly inclined 

 stratification, vipon the eroded western edges of the similarly almost hori- 

 zontally bedded Silm-ian rocks. Undoubtedly a i)art of the salt contained 



'Translations of their Ojiliway names, aecording to Rev. J. A. Gilfillan, Fifteenth Annual Report, 

 Geol. and Nat. Hist. Survey of Minnesota, for 1886, p. 463. 



