OF ARKANSAS. 923 
es 
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 for 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 bé 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 mur. Ed- 
ward’s dwelling, Dwight mission, Illinois bayou: 
Thin-bedded sandstone, top of the hills. +.+ +e sees eee eee ee aes 10 feet. 
Reddish, ferruginous, argillaceous shale, with nodules of iron 
ORO Wasa eae tl ed aii aera arGe a aera aie adva wiard uae tueas 60 « 
Shaly argillaceous carbonate of iron: + +++ eee eee cere e eee 3to 5 « 
Dark shale with fossil plants, lepidcdendron and stigmaria-: - 2 8 
Band of sandstone in two layers (local). + +++ sees e eee cece ees Q 6 
Alluvial bottom: +s ses e cece ee cere eee eee tence anes eae 20 «Ct 
Bed of Illinois bayou: aay aupaneran sapien saikevtayseauie Og aa AiG hee cartes eo alesse aeT a EL Le Oo « 
$9 feet. 
The shaly argillaceous carbonate of iron in this section, is of excellent 
quality and sufficiently abundant fer 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 argillacecus iron ore were observed in the 
vicinity of Dover, but not in the same abundance as further south. 
