1'KORIA COUNTY. 337 



eastern portion of tbe county the drift beds presented no decided indi- 

 cations of having been subjected to tbe modifying influences observed 

 further south, and they attain a greater thickness here than in any 

 other portion of the county. In the bluffs west of Mossville they are 

 fully two hundred feet thick, as shown by measurement where the road 

 leading out to the prairie ascends the bluff, and consist of brown and 

 dark-bluish colored clays, with gravel and boulders. The upper por- 

 tion of this deposit here is a brown clay, comparatively free from 

 gravel, and thirty to forty feet thick. Striking the prairie road about 

 three miles west of Mossville. and turning south to Peoria, no indica- 

 tions of the presence of any stratified rocks were seen in any of the 

 gulches intersecting the bluffs, although careful examinations were 

 made. Hence we may safely conclude that the western borders of the 

 old valley in this vicinity were at least three miles to the westward of 

 the present line of bluffs. 



On the south side of the Kickapoo, and in the central and northwest- 

 ern portions of the county, the stratified rocks of the Coal Measures 

 outcrop on all the streams, and the overlaying drift beds are compar- 

 atively thin, ranging all the way from four to sixty feet. At Chase's 

 quarries, three miles north-east of Princeville. the drift clays are only 

 from three to four feet thick, with aboivt a foot in thickness of sand 

 resting directly upon the limestone ; and at several other points in this 

 vicinity the bed rock was seen outcropping within a few feet of the sur- 

 face. It is probable this limestone formed a barrier reef during the ac- 

 cumulation of the drift, and the transported material was thus diverted 

 into the deeper channels on either side. South of the Kickapoo the up- 

 lands are covered with drift clays, that are generally from forty to fifty 

 feet in thickness and spread quite uniformly over the surface. Along 

 the river bluffs the marly, buff colored beds of the loess cap the high- 

 est points, but north of the Kickapoo we did not meet any beds that 

 could be properly referred to this age. unless the brown clay immedi- 

 ately below the soil may be so referred. 



The only fossils of this age that have come under my notice from this 

 county are the remains of a mammoth, consisting of two molar teeth, 

 with a portion of the jaw, which was found by Captain Smith in the 

 gravel bed Xo. 2 of the foregoing section, in the Peoria bluff. A por- 

 tion of one of these teeth, with a part of the jaw, now belongs to the 

 State cabinet, as a contribution from its discoverer. In a boring made 

 near Chillicothe a few years since, an ancient copper coin was reported 

 to have been found at a depth of li'L* feet, but it might have been drop- 

 ped in from the surface for the purpose of deception, or fallen down 

 accidentally from some layer near the surface. This coin has been fig- 

 ured and described in the Transactions of the American Philosophical 



