IVBR 



C* A Olr 



STEPHEXSOX COUNTY:. 



surrounding waste of waters. The rocky surface tliu.s left, so far as we 

 can judge from the limited examinations we are now able to give that 

 surface, would be unsinoothed by water current and iinscratched by 

 glacier, but would be everywhere uneven, rough, and covered with un- 

 worn fragments of stone. 



Along the narrow bottoms of the Pecatonica may be noticed a strip 

 of alluvium proper. At some places it is very narrow, at others it ex- 

 tends to one or two miles in width. The same deposit may be observed 

 at a few localities along the Yellow creek bottom, and also along the 

 narrow bottoms of some of the smaller streams. The deposit, however, 

 is of limited extent ; it is rich, fat, and heavy as an agricultural and 

 timber soil. Along some of these streams the low, bald hills are found 

 to be composed of the loess marls and clays ; but this deposit is also of 

 quite limited extent in the county. All the rest of these superficial de- 

 posits belong to the sands, clays and gravels of the drift proper. These 

 clays and clayey sands, however, do not very strongly furnish the evi- 

 dences of deposition or transportation. They seem to partake, in part 

 at least, of the nature and character of the rock formations lying imme- 

 diately below them. In every instance examined this seemed to be true. 

 Where the Galena limestone is the underlying rock, the appearance was 

 somewhat as follows: First there was the prairie soil and clayey sub- 

 soil, at most only a few feet in thickness; this was succeeded by a red- 

 dish-brown clay, mixed with flints and pieces of cherty Galena limestone; 

 then came the clay and pieces of the limestone preserving their regular 

 stratification, the limestone becoming more abundant in the descent, 

 until the solid rocky strata was reached. In a few instances this over- 

 lying clay is creamy in color, and almost limey in texture; but the pre- 

 vailing color is reddish-brown or red, and in many cases it is more or 

 less mixed with sand. The clays overlying the Cincinnati shales also 

 bear a resemblance to this formation, from which they are doubtless in 

 part derived. They are of a creamy or more chocolate color, finer in 

 texture and freer from sand. These superficial clays and loams certainly 

 have the appearance of being the residuum left after frost and water 

 had pulverized, and, by percolation, removed the more soluble portions 

 of the uppermost parts of the formations below. 



But, aside from these deposits, the gravel beds and boulders of the 

 true drift period are not wanting in this county. That part lying west 

 of the Illinois Central Railroad and south of Yellow creek being mostly 

 low, level prairie, underlaid mostly by the Cincinnati shales, and also 

 that low, rich, level part between Waddain's Mound and the range of 

 mounds running from the neighborhood of Warren towards the south- 

 west, ami underlaid by the Galena limestone may almost be denomi- 

 nated a driftless region. Few boulders are seen over it, and few or no 



