JO DAVIESS COUNTY. ;]1 



water to flow over it. and submerge the lead basin. In this way the 

 action of the drift forces would be greatly modified. 



My ov.n observations upon the drift phenomena in this county have 

 not been altogether satisfactory. In the first place I do not think it a 

 driftless region. In addition to the drift pebbles and copper nugget re- 

 ferred to. by 1'roiVssor WnirniEN. as having been found at the Califor- 

 nia lead diggings. 1 have observed numbers of large boulders lying over 

 the prairie land in the eastern and south-eastern portions of the county: 

 and I am credibly informed, that, on the high upland some three miles 

 north of Galena, many boulders of a sort of buhrstone, whose parent 

 outcrop is far north in Wisconsin, are strewn over the ground. Many 

 of the clay deposits covering the very lead veins themselves, do not 

 dift'er materially from the buff and yellow clays treated, and recognized 

 everywhere else in the north-west, as true drift clays. The river ten\r 

 and stratified loess deposits, above spoken of ; the lithological charac- 

 ter of the clays just referred to ; the fesv nigger heads" and lost rocks 

 found in several places in the county, show unmistakably, I think, that 

 the drift forces, especially towards the close of the drift epoch, had 

 much to do in cutting down, carrying away, and arranging the great 

 rocky formations which once existed, but which have now disappeared 

 over large portions of the county. Over more than half its area, perhaps, 

 the whole thickness of the Niagara limestone and the Cincinnati shales 

 have disappeared, except the mounds left standing as sentries, at long 

 intervals : and the very Galena bed rocks below where they used to 

 stand, have had their surfaces denuded, to a considerable extent, in the 

 operation. To one standing upon one of these mounds, and looking 

 over the valley -like expanses between them, with the eye of a geologist, 

 the conviction, that he is standing upon the old Silurian level of the 

 country, grows into a certainty. Eroding and denuding influences have 

 removed from three hundred to three hundred and fifty feet of Magne- 

 sian limestone and shales. It is impossible to suppose that simple 

 atmospheric or chemical causes, acting no matter how long, could pro- 

 duce such gigantic results. Many siibmergeucies and upheavals may 

 have taken place; the dynamical powers of heavy bodies of water and 

 water currents, and other drift forces, must have acted long and pow- 

 erfully in bringing them about. 



While these things all appear to be true, it cannot be denied that the 

 superficial deposits covering the bed rocks, are, in part, derived from 

 their disintegration, by rains, frosts, ^ind other atmospheric and chemical 

 agencies. I have examined many clay banks through the lead mine 

 region, which bore unmistakable evidences of this. Those peculiar red 

 clays, characteristic of the lead region, if dug into, show, first, the clays 

 and hard pan, without rocks of any description, but as the deposits are 



