OF ARKANSAS. 233 



sandstone to protect them, have been worn away and filled up the ine- 

 qualities of the surface. 



Throughout all this southern part of the county, thin beds of semi-bitu- 

 minous coal are found. One of the principal openings lor coal, is in the 

 bed of the Illinois bayou, near Dwight mission; but, at the time of my 

 examination of this county, the river was too high to admit of its being 

 seen. Mr. Edwards informed me that it was 15 or 20 inches thick. The 

 geology of the adjacent country leads me to believe that it will be found 

 to occupy the same geological position as the coal described on Horse- 

 head creek, in Johnson county. 



The following section exhibits the succession of the rocks at lur. Ed- 

 ward's dwelling, Dwight mission, Illinois bayou: 



Thin-bedded sandstone, top of the hill xd feet. 



Reddish, ferruginous, argillaceous shale, with nodules of iron 



ore GO " 



Shaly argillaceous carbonate of iron 3 to 5 " 



Dark shale with fossil plants, lepidodendron and stigmaria* • 2 " 



Band of sandstone in two layers (local) 2 " 



Alluvial bottom 20 " 



Bed of Illinois bayou " 



99 feet. 



The shaly argillaceous carbonate of iron in this section, is of excellent 

 quality and sufficiently abundant fcr the supply of smelting furnaces. It 

 contains 32.2 per cent, of metallic iron, and is similar in its composition 

 to the best quality of the ore from the Cross Basket mines, in Scotland, 

 used at the Clyde iron works. Iron made from this class of ores is of the 

 finest quality, combining strength and ductility. 



This description of ore, will no doubt be found at many other localities 

 in the vicinity of Dwight mission, and must eventually attract the enter- 

 prise of the' iron manufacturer, from its vicinity to the. Arkansas river 

 and proximity to large forests of pine timber, and to the workable coals 

 of Johnson county; especially the Spadra mines described in Dr. Owen's 

 Report. The coal which is exposed in the bed of Illinois bayou, at low 

 water, may be reached by a shallow shaft at the base of the section at 

 Dwight mission, and may be worked by the removal of 8 or 10 inches of 

 the shale roof. 



Considerable quantities of argillaceous iron ore were observed in the 

 vicinity of Dover, but not in the same abundance as further south. 



