PIPESTOKE AND ROCK COUNTIES. 545 



Kame-like deposits.] 



This finer till, or pebbly clay, seems to have the age of the till on which it 

 lies, rather than of that accumulated by the last glacial epoch, and seems 

 to require the presence and action of a lake of standing water at the mo- 

 ment of deposition.* The water in such case would not only produce such 

 plasticity in the till as to allow the heavier and coarser components to 

 seek the bottom of the mass, but perhaps to cause their dislodgment from 

 the ice, and their deposition somewhat earlier than the great mass, the 

 smaller stones and pebbles being retained and more thoroughly mingled 

 with the clay. 



Kame-like deposits. In the south part of Spring Water the surface is 

 principally till, but knolls or swells are found occasionally to consist of 

 gravel and sand ten to twenty feet deep. These deposits of modified drift 

 seem to be of kame-like origin, and to be of the date of the earlier glacial 

 epoch, due to the rapid action of rivers on the drift at the time of its dep- 

 osition. Such water was probably confined within gorges in the ice, and 

 had ample facility for washing the till as fast as brought forward by the 

 ice, carrying away the clayey constituents and leaving only the coarser. 



Other localities of similar deposits, consisting partly of till and partly 

 ot sand, are seen in the S. W. \ sec. 20, Denver. Here a few knolls and 

 short, rough ridges, with abundant boulders up to two feet in diameter, 

 rise from twenty-five to forty feet above the general level. Again, in the 

 west part of section 8, Eden, Pipestone county, are other kame-like accu- 

 mulations, largely consisting of till with many boulders, sometimes five 

 feet in diameter, but mostly smaller. These rise from twenty to thirty 

 feet above the surrounding country. Similar, but perhaps somewhat 

 higher hills and swells are seen in the east edge of this township (probably 

 section 13), and the adjoining part of Elmer. 



The level terrace of gravel and sand, underlain by till, on which Ed- 

 gerton is built, is about two-thirds of a mile in extent from west to east 

 with a hight thirty to forty feet above the Rock river. 



Boulders. The "three maidens" and the three others (smaller) that 

 make up the cluster of six lying just outside the Indian reservation at the 

 pipestone quarry, fig. 42, rest on the surface of the red quartzyte about 

 sixty rods southeast of the quarry and at the foot of the long ledge or es- 



Compare Geology of Ohio, vol. i, p. 606: vol. ii, p. 232; Proo. Am. Assoc. Adv. Soi., 1872, vol. xxi., p. 182. 

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