T)V) The Ice-cuyrcnfi^ of Minnciota- UpliuDi. 



Farmiiigton, oeiiig bounded on its northeast side along ihis ex- 

 tent of eiglit miles by the plain of modified drift, 30 to 50 feet 

 higher, on whicdi the village of Rosemount is built. 



Southwest of this channel, the road to Fairfield in its next three 

 miles crosses massive swells or hills of till, 75 to 100 feet higher, 

 and nearly as much above another plain of modified drift, which 

 lies in the south })art of Lakeville and jiortheastern Eureka, ex- 

 tending east to Farmington, and merging with the great expanse 

 of this formation before described as reaching from west to east 

 through the center of Dakota county. Farmington and Fairfield 

 are situated on this belt of modified drift. It narrows in its west 

 extremity from an average width of two miles to only about a 

 quarter of a mile at the southeast end of Lakeville lake, which like 

 Crystal lake, seems to mark the point in the terminal moraine 

 where the waters of glacial melting had a principal outlet. . 



The channel which seems to have been formed by the waters 

 discharged from the margin ofthe ice-sheet at the junction of ita 

 opposing currents, when the second or inner terminal moraine ofthe 

 last glacial epoch was being accumulated, is well known under the 

 name '' Rich Valley." This is fi-om one quarter to three quarters 

 of a mile wide, with a bottom consisting, like the '' low prairie," 

 of stratified gravel and sand. It is bounded on each side, for the 

 most part, by moderate slopes of the same materials or of till, 

 rising 25 to 50 feet higher. Beginning within the hilly belt of 

 the terminal moraine in tlie southwest quarter of section 20, Inver 

 Grove, this valley extends with a course a little to the east of 

 south four miles, to itich Valley postoffice in the northeast corner 

 of section 20, Rosemount. At the north side of this and and the 

 adjoining section 25, Rich Valley is turned east by a swell of till, 

 a mile and a half long from west to east and about a third of a 

 mile wide, which rises some 75 feet above this valley and 40 feet 

 above the adjacent Ro-'emount plain. Thence tlie course of the 

 valley is east-southeastward, passing through sections 30, 2U and 

 28, in the east part of Rosemount. 



A great glacial river appears to have flowed to the head of Rich 

 Valley in Inver Grove, passing through the terminal moraine in 

 the northeast ])art of Eagau, where the railroad now runs on a 

 belt of undulating modified drift, from a quarter of a mile to one 

 and a half miles wide, in some porlions enclosing numerous hol- 

 lows and lakelets 25 to 75 feet below the general level, to which 

 deptli, at least, this deposit of gravel and sand extends. 



