38 THE GEOLOGICAL STRUCTURE, ETC. 



as to prevent comparatively free circulation, the facilities for the 

 discharge of water are less than are demanded by the quantity 

 capable of being received ; hence the rocks have a tendency to be 

 full up to the brim, and the pressure recorded to be greater. A 

 further indication of the eastern movement of the water is found 

 in the fact that the hydraulic head rises from east to west. 



An analysis of the water in the Jamestown well has been 

 made, and shows that it contains in addition small quantities of 

 silica and alumina, carbonates of iron and lime, sulphates of 

 lime, magnesia, soda, and potash as well as 21 grains per gallon 

 of common salt. This mineral matter which gives the water 

 such a characteristic taste is probably derived from the beds 

 through which it percolates for hundreds of miles. 



" Much shale, gravel, and detritus, rich in sulphates, are 

 " present in the glacial drift over nearly the entire Red River 

 " Basin, and the percolating rain water found by the fresh artesian 

 " wells in the drift of the southern and northern ends of the 

 " Red River Valley, has acquired minute quantities of alkaline 

 " and saline matter. But where its proportion is large, as in 

 " the brackish water of the wells from Crookston, and Blanchard 

 " northward to the edge of Manitoba, it seems impossible that 

 " so remarkable a difference can be due to diversity in the 

 " material of the drift, or to longer time and better opportunity 

 " afforded to the water for such impregnations while percolating 

 " through porous beds or veins in the drift. The saline and 

 " alkaline artesian waters of the drift, gravel, and sand along 

 " this central portion of the Red River Valley therefore appear 

 " to be received mainly from the same Dakota Sandstone which 

 " supplies the deep wells of the .James River Valley. Several 

 " wells in the vicinity of Blanchard and Mayville, 375ft, to 404ft. 

 " in depth, pass through the drift and enter a very fine white 

 " sandstone, proably the Dakota formation, from which they 

 " obtain flows of brackish water. About a dozen miles east of 

 " Blanchard the drift was found to have a total thickness of 

 " 310ft., below which a boring went 107ft. into exceedingly fine 

 " white sandstone, finding, however, no artesian water, apparently 

 " because of the very close texture of the rock. The top of the 

 " sandstone in these wells is 650ft. to 575ft. above the sea. If it is 

 " the Dakota Sandstone, as seems probable, it has an ascent of 



