DETAILED RECORDS. 235 
MINNESOTA. 
723. Well at South Minneapolis, Hennepin County. 
[Authority, Chicago, Milwaukee and St. Paul Railway, owner. No samples.] 
Minneapolis is near the center of an artesian basin that underlies a considerable area in 
outheastern Minnesota. The rock strata forming the basin are of Ordovician and Cam- 
>rian age. The formations penetrated by this well, below the drift, are, according to the 
lomenclature of the Minnesota Survey: "Trenton" limestone, St. Peter sandstone, Shako- 
>ee limestone, New Richmond sandstone, Oneota limestone (Ordovician); Jordan sand- 
tone, St. Lawrence sandstone, shale and limestone, and Dresbach sandstone (Cambrian) 
Record of well at South Minneapolis. 
Feet. 
>oil and surface material 0- 56 
'Trenton " limestone 56- 84 
>t. Peter sandstone ". 84-250 
Jhakopee dolomite 250-260 
tfew Richmond sandstone 260-267 
)neota dolomite 267-390 
Jordan sandstone 390-478 
Dresbach sandstone 478-704 
Well has brick curb, to 20 feet; casing from 20 to 184 feet; no casing below. 
727. Well at Fergus Falls, Ottertail County. 
Well begun October 4, 1904; completed April 15, 1905. Authority, John Shogren, driller. Samples 
preserved.] 
| This well is sunk wholly through beds of clay and sand that were deposited during the Ice 
iYge by glaciers or by streams deriving their waters largely from glaciers. It shows how 
lleeply this glacial material has covered the old rock surface at some localities and how 
rregular is the distribution of water-bearing beds. 
Record of well at State Hospital for the Insane, Fergus Falls. 
Feet. 
black soil 0- 2 
Soft yellow clay 2-56 
lard blue clay and sand with numerous bowlders from 64 to 120 feet 56-120 
5oft gray sand; some water " 102-215 
Lft blue clay 215-224 
toft gray sand 224-241 
Lft blue clay 241-249 
Hard blue clay 249-260 
Lard gray clay and sand 260-314 
jray gravel; water-bearing; well pumps 45 gallons per minute, water standing 97 
'! feet from surface 314-315 
lard gray, dry sand 315-358 
laid gray "shale" and clay 358-400 
liay gravel; main water supply 400-420 
|Iard, blue clay 420-422 
Rig used, cable. Casing used, 12-inch, to 215 feet ; 10-inch, 180 to 366 feet ; 8-inch, 300 
o 325 feet ; 6-inch, 310 to 400 feet. Water stands at 97 feet from surface. Well pumps 100 
;allons per minute from a depth of 160 feet. Quality, hard, alkaline. 
