WATONWAN AND MARTIN COUNTIES. 479 



Third terminal moraine.] 



above the general level. In northeastern Kossuth county this tract expands 

 to a width of ten miles and reaches from Ramsey, at the east side of Union 

 slough, north and northwest to the state line, lying on both sides of the 

 head-stream of the Blue Earth river. Its northeast border is in the south 

 edge of Elniore and Pilot Grove in southwestern Faribault county, where 

 it consists of hillocks and short east-to-west ridges of till, 30 to 50 feet high. 

 Thence these accumulations of till occur scatteringly in southeastern Mar- 

 tin county to East Chain and less prominently to Fairmont. In these 

 townships the contour is seldom rough, but rises in swells 25 to 50 feet 

 above intervening depressions, with trends more frequently from north- 

 west to southeast than in other directions; while nearly all the remainder 

 of this county is more smoothly undulating, in longer slopes, with the 

 highest parts only 10 to 2D feet above the lowest near. 



The belt of hilly and. rolling glacial drift thus traced from Iowa into Minnesota was probably 

 accumulated as a terminal moraine at the end of the ice-lobe which extended southeastward from 

 the Leaf hills and the Head of the Coteau des Prairies, as more fully explained on page 406; 

 but at a late part of the epoch, after two distinct recessions of the ice had taken place in south- 

 western Minnesota. When this lobe of the ice-sheet attained its greatest area it terminated on 

 the south in the vicinity of Des Moines, and was bounded on its sides by the outermost belt of hilly 

 and knolly drift deposits. On its east side only two morainic belts are found, but on its west side 

 three are clearly distinguished in the west edge of this state and the east edge of Dakota.* At 

 the time of accumulation of the second belt of morainic drift, the end of this ice-lobe had receded 

 to Mineral ridge in the north part of Boone county, Iowa; and when the third belt was formed, 

 its extremity appears to have been in Hancock county, Iowa. The length of this ice-lobe was 

 thus diminished forty miles between the times of formation of its first or outer moraine and its 

 second or inner moraine, and was still further shortened seven ty-tive miles before its third moraine 

 was accumulated. Across the area from Fairmont northwest to Yellow Medicine county this 

 third moraine was not noticed as a continuous formation. In the line where it would be looked 

 for, we find the surface somewhat more prominently rolling than ordinary in Waverly, at the 

 north side of Martin county; but only the usual low undulations were noted northwestward in 

 Watonwan county. The nearest tract of typically morainic contour observed in this direction, 

 which seems to be probably a part of this belt, is thirty miles from Waverly in the north part of 

 Stately, the most southwestern township of Brown county .t 



For one or two miles southeast and south of Madelia, and for one mile southeast of Saint 

 James, the surface has frequent swells twenty to thirty feet above the depressions, being more 

 rolling than most other parts of Watonwan county, which is generally very gently undulating in 

 smooth prolonged slopes, with occasional lakes and here and there sloughs ten to twenty feet 

 below the highest portions of the adjoining country. 



Chains of lakes. It has been frequently noted that the lakes which 

 abound upon areas overspread by the glacial drift, have their prevailing 

 trend, or average direction of their longer axes, parallel with the course 



