PLATE IATI1. 



KITTSON, ROSEAU AND MARSHALL COUNTIES, 1899. J. E. TODD. 



The area of these counties was embraced within the basin of lake Agassiz, and 

 is flat and often swampy. It is crossed, fortunately for travel, by the gravelly beaches 

 of that lake, but their actual location has not been determined in detail, except in 

 a part of the area. A belt of lacustrine clay accompanies the Red River of the North, 

 from fifteen to eighteen miles wide, and similar clay is found elsewhere, especially 

 along the Roseau river, in Roseau county. There is higher and dryer land in south- 

 eastern Marshall county, and especially on the west side of Thief river, in that county, 

 and also in the southeastern part of Roseau county. These tracts, connected with a 

 larger tract further east, were probably a part of Beltrami island, which rose above 

 the waters of lake Agassiz. 



The streams have excavated but shallow channels in the clayey drift, and in no 

 place have they uncovered the bedrock, so far as known, thus proving the compara- 

 tive recentness of their birth. They sometimes lose themselves in superficial marshes, 

 or muskegs, and spread over much of the country, reappearing again at the points 

 of drainage from those marshes. 



Mr. Todd thinks that the last point uncovered by the glacier was the north- 

 eastern part of Roseau, and the latest uncovered by the retreat of lake Agassiz was 

 the northwestern part of Kittson county. 



In the northwestern part of this area is much salt water. This permeates much 

 of the surface water in the vicinity of saline springs. Such water is found, by sinking 

 deep wells, not only in the gravelly beds in the drift, but also in the underlying rocks. 

 A well at Humbolt penetrated to the depth of 644 feet. At 180 feet it entered a coarse 

 magnesian limestone, the lithologic characters of which are like those of the Lower 

 Magnesian of the Mississippi valley. This is 295 feet thick. Beneath this was a 

 sandstone of rounded quartz grains, having a thickness of seventy-one feet. Then 

 came shale, red, green, unctuous, gritless, resembling the red shale that has been 

 penetrated at a number of places in the central part of the state, lying below the St. 

 Croix sandstone, having a thickness here of ninety-two feet. The drill then entered 

 mica schists of the Archean and the work ceased. Brine flowed constantly from this 

 well after it reached the depth of 165 feet, in the drift, and increased in amount in 

 the sandstone below the magnesian limestone. On analysis this brine was found to 

 be superior to that used in Michigan for the manufacture of salt, and if fuel could be 

 got cheap enough, or perhaps even by solar evaporation alone, it could be made a 

 source of revenue to Kittson county. N. H. w. 



