PIPESTONE AND ROCK COUNTIES. 543 



Pipestone. Drift.] 



vails in the formation to which it pertains, it should be added that this 

 redness suffers all the variations that it does in the quartzyte. It passes 

 nearly to white, through pink; it is intensified to a brown, and in small 

 patches it is deepened to lilac or lavender-brown, becoming reddish purple. 

 It is only with a loose application of the term that it can be styled "gray," 

 a color which is derived from a mixture of black and white, and which is 

 applicable to the schists and quartzytes of the northern part of the state 

 pertaining to a lower geological horizon. 



Mr. Upham notes that Mr. McDermott found numerous pieces of pipestone about seven feet 

 below the surface near the base of "the mound" near Luverne, in excavating to improve a spring 

 near his house. This was partly light-colored, and partly of a deep red color, and was thought to 

 be from a layer in place, near the base of "the mound." Mr. Upham also reports pipestone from 

 section 20, Rose Dell, where it appears upon a little ridge about a quarter of a mile long from 

 northwest'to southeast, having the usual colors and character. This is on the authority of D. E. 

 Runals, of Edgerton. Further statements respecting the uses of this pipestone, will be found 

 under archceology, at the close of this chapter. 



The drift. Till. These counties lie mainly outside of the great moraine 

 that crosses the southwestern portion of the state, and their drift features 

 present some peculiarities. They are still, in general, till-covered, that de- 

 posit exhibiting a thickness, and a general uniformity in its features equal 

 to, if not greater than, many of the counties that lie within the morainic 

 belt. That is to say, its composition does not change so frequently to 

 gravel and sand, and its upper surface is not so frequently broken by hil- 

 locks, or depressed by short valleys. Yet toward the south it exhibits 

 features that seem to indicate its greater age. Its gravel stones, particu- 

 larly those of limestone, are rotted. Its boulders become less conspicuous 

 and apparently less numerous, at least superficially, and it assumes a peb- 

 bly rather than a stony composition. Within it appear those limy concre- 

 tions that have frequently been mentioned in describing the loam of the 

 Mississippi and Missouri valleys. These concretions accompany this peb- 

 bly composition, until by the gradual withdrawal of the pebbles, there is 

 found a fine, clayey loam which cannot be distinguished from the loess- 

 loam of the Missouri valley. This transition does not involve the whole 

 thickness of the till, but pertains to its upper portions.* At a few feet 

 below the surface the till, even in the southern part of Rock county, is 

 stony. 



Compare the report ou Kilhuore county, pp. 311-317. 



