* 

 464 THE GEOLOGY OF MINNESOTA. 



[Modified drift. Boulden. 



belt of similar contour, which seems to be a terminal moraine, reaching in 

 Iowa through the north part of Hancock county, southwestern Winnebago, 

 and northeastern Kossuth county, into Minnesota. 



The most noteworthy hill of this area in Elmore is in the north part of section 32, rising 50 

 to 60 feet and about a sixth of a mile long, trending from east to west. In the south part of sec- 

 tions 25 and 26, Pilot Grove, hillocks and short ridges form a somewhat continuous east-to-west 

 series, 40 to 50 feet high. These accumulations are chiefly till, differing from its level or moder- 

 ately undulating tracts in a greater abundance of boulders; but occasional knolls, sometimes the 

 highest of their vicinity, are composed of obliquely stratified gravel and sand. In sections 29 and 

 32, Pilot Grove, these morainic deposits are inconspicuous or wanting; next they rise to the hight 

 of 30 to 40 feet in section 31 and the south half of section 30, at the southwest corner of Faribault 

 county; and thence they occur scatteringly all the way northwest to East Cha n, and less promi- 

 nently to Fairmont. In this distance their material, and that of the whole region about them, is 

 till. Their contour is seldom rough, but rises in swells, 25 to 50 feet above intervening depres- 

 sions, with trends most frequentiy from northwest to southeast. 



Modified drift. Kames occur three miles south of Walnut lake, in sec- 

 tion 23, Brush Creek. They consist of short northwest to southeast ridges 

 and round or conical knolls, steep-sided, about twenty feet high, composed 

 of coarse gravel and sand, and form a series three-fourths of a mile long. 

 The region surrounding them is slightly or moderately undulating till. A 

 portion of the moraine, situated in sections 16 and 8, Walnut Lake town- 

 ship, two and a half to five miles northwest of the lake, is formed of kame- 

 like deposits, accumulated in swells, knolls and northwest to southeast 

 ridges, thirty to forty feet high, of very gentle slopes, composed mainly of 

 stratified sand and fine gravel, as shown by wells, which do not reach the 

 bottom of t]^is modified drift at the depth of fifty feet. 



Alluvium. The stratified clay and sand used for brick-making at Blue 

 Earth City, and other similar beds of small extent, appear to be alluvium 

 laid down along the avenues of drainage after the glacial lake that had 

 covered this area was withdrawn by the departure of the ice-sheet which 

 had been its northern barrier. 



Pebbles and boulders. On the Kiester hills pebbles and boulders occur 

 more plentifully than on the lowlands, but are not usually very abundant, 

 and blocks more than five feet in diameter are rare. About one-twentieth 

 part of the large boulders and probably one-fifth of all the pebbles are 

 limestone, often obscurely fossil iferous. The greater part of the rock- 

 fragments, especially the larger blocks, are granite, syenite, gneiss and 

 crystalline schists. One boulder, ten feet long, of garnetiferous horn- 

 blende schist, was noted here. A greenish slaty rock is also sparingly 



