134 Artesian Well Boring in Southeastern Minnesota — Hall. 



and Minneopa in the Minnesota river valley; probably at Lnnes- 

 boro and Quincy; in Barn bluff at Red Wing; and in the bluffs 

 of eastern Winona county and of Hokah." 



It yields more water than either of the layers above it. 



10. The St. Lawrence. — Then comes the St. Lawrence for- 

 mation of dolomitic limestone and shales underlying an equally 

 large area with the Jordan sandstone above. "Thickness in Min- 

 nesota, 128 feet in E. Minneapolis well; 213 in Hastings; 160 feet 

 in Mankato; and 170 in the old quarry east of Hokah; in Wiscon- 

 sin, the Mendota limestone of Irving, with 30 feet of strata below, 

 60 to 75 feet; in Missouri, the Third magnesian limestone, 350 feet. 

 This is the St. Lawrence of the Minnesota geological reports at St. 

 Lawrence, Hebron and Jordan, but not in Houston, Olmsted, 

 Fillmore and Winona counties, where this name is applied to the 

 same formation that is called Shakopee in the Minnesota river 

 valley, lying above the limestone at St. Lawrence; excepting per- 

 haps at Wh&len and Lanesboro, where apparently the true St. 

 Lawrence is found." Upham. 



11. The Dresbach Sa^^^dstone (The upper Saint Croix). — 

 The fourth sandstone is the one that Mr. Upham locates '^at the top 

 of the Saint Croix." It is the formation which appears in the 

 banks of the Mississippi at Dresbach, Dakota, etc., and is called in 

 Minnesota the Dresbach sandstone. Its color is at Dresbach a 

 light, rather pleasant gray, and its thickness in Minnesota is 50 

 feet or more; in Wisconsin near Madison, 54| feet; in Missouri 

 the Third sandstone of Swallow, 60 feet. 



12. The Saint Croix Shales (The middle Saint Croix). — 

 Below the preceding number, called the Dresbach sandstone, the 

 second member of the great Saint Croix series consists of shales and 

 shaly sandstones. A calciferous character is taken on in places as 

 near St. Croix Falls, Wis. ; and in Missouri it becomes the Fourth 

 Magnesian limestone, 200 or 300 feet thick. In this state, so far 

 as determined by well borings, its thickness is 115 feet at Hast- 

 ings; 75 feet at Mendota; and 170 feet at East Minneapolis. 



13. Tht^j Saint Croix Sandstones (The lower Saint Croix). 

 — This formation consists chiefly of white sandrock which at Hast- 

 ings is 230 feet thick, and 395 feet at Brownsville. "This is the 

 sandstone of the Chippewa, Black and Wisconsin rivers, 50 to 

 100 feet thick." Upham. Water is always found in this layer, 

 and so far as tested, the supply is a large one, as shown by the 



