SURFACE DEPOSITS. 99 



the whole having an elevation probably nowhere exceeding 

 fifty feet above the general surface, bnt being in an open 

 prairie region it attracts attention at considerable distance. 

 It is composed wholly of drift, and it is perhaps needless to 

 say, that it is not likely to yield any "mineral" to explorers, 

 as its name might suggest a hope for. 



The other ridge extends from the eastern part of Palo Alto 

 county through Kossuth into Hancock. The greater part 

 of this ridge has the general, but indistinct character of a 

 terrace, facing the south, and elevated only from fifteen to 

 twenty or thirty feet above the general level of the surface to 

 the southward, while the general level to the northward 

 stretches away from the top of it. It is nowhere very 

 distinctly marked even in so flat a region as this, but yet it is 

 sufficiently so to have caused its existence to become generally 

 recognized by the inhabitants. Its eastward extension into 

 Hancock county becomes broken up into a well-marked strip 

 of " knobby country." Here it consists of elevated knobs and 

 short ridges wholly composed of drift, and usually containing 

 more than an average proportion of gravel and boulders. 

 Interspersed among these knobs and ridges are many of the 

 peat marshes of that region. One knob in the extreme north- 

 eastern corner of Hancock county, is well worthy of especial 

 notice on account of its height. It is visible above all the 

 others, and at considerable distances in the country around. 

 It is estimated to be at least three hundred feet above the 

 water of Lime creek, near which it is located. It is a 

 conspicuous object in the region around, and is called "Pilot 

 Knob," by the inhabitants. Some other matters relating to the 

 drift, but more especially local in their character, will be 

 referred to in the chapters on County and Regional Geology . 



Close of the Glacial Epoch. What was the real condition 

 of the surface previous to the Glacial epoch we can never 

 fully know; but its features were certainly largely obliterated 

 by the action of the glaciers and the accumulation of the drift, 

 so that at its close the surface of our State was comparatively 

 a uniform level, unmarked by strong features and without a 



