110 GEOLOGY OF ILLINOIS. 



outcrops examined did not promise well as a building stone. The lime- 

 stone which outcrops along the river is thicker bedded than in Cumber- 

 land, and between the railroad bridge and the mouth of Brush creek 

 quarries have been opened in it at several points, where a hard brownish- 

 gray limestone in beds from four to eighteen inches thick has been 

 obtained for building purposes. The western portion of the county is 

 quite destitute of rock of any kind except the drift bowlders found 

 upon the surface or in the valleys of the small streams. 



■ Lime. — The limestone on the Embarras is too argillaceous to be suc- 

 cessfully used for making quick lime, and as this is the only limestone 

 of any considerable thickness found in the county, some other region 

 must be depended on for a supply of this article. 



Clay and Sand. — Brick clays are easily obtained from the subsoil in 

 almost any portion of the upland, and a potters' clay of fair quality is 

 found in the drift deposits on the Kickapoo. Sand can be readily 

 obtained either from the beds of the streams, or may be found in many 

 places interstratitied with the drift clays. 



Iron ore. — Bands of carbonate of iron in small quantities were found 

 interstratified 'in the shales above and below the heavy bed of sand- 

 stone that forms the lower portion of the bluffs on either side of the 

 Embarras river. 



Soil and Timber. — The prairies in this county, which constitute by far 

 the greater portion of its surface, have a deep, black, loamy soil, highly 

 fertile, and ranking among the best prairie lands in the State. On the 

 timbered ridges adjacent to the streams the soil is thinner, but never- 

 theless productive, and especially adapted to the cultivation of wheat 

 and other small grains, clover and fruit. On these ridges oak and 

 bickory is the prevailing timber, but as the surface becomes more level 

 toward the prairie region, we also find elm, linden, hack berry, wild 

 cherry and honey locust, and on the bottom lands along the streams 

 cottouwood, sycamore, ash, red birch, willow, coffeenut, black walnut, 

 white and sugar maple, etc., etc. 



Douglas County is bounded on the north by Champaign, on the 

 east by Edgar, on the south by Coles, and on the west by Moultrie and 

 Piatt. It embraces eight full and seven fractional townships, which 

 give it an area of about four hundred and ten square miles. The Okaw 

 or Kaskaskia river drains the western portion, and the Embarras the 

 central and eastern portion of the county. These streams are skirted 

 with timber, but the greater portion of its surface is prairie. 



The whole area of the county is covered so deeply with drift clays 

 that there is no outcrop of the underlaying Coal Measure strata in the 

 county. From the exposures in the adjoining counties it is kuowm that 

 the underlaying beds belong to the upper Coal Measures, and probably 



