OF ARKANSAS. V7 
Immediately overlying this black shale is a black, bituminous limestone, 
much of the same character as that already mentioned as occurring in the 
Oil-trough ridge, and occupying very nearly the same geological horizon. 
The section in Wiley’s cove is approximately as follows: 
1. Archimedes limestones. 
2. Encrinital, and Chonetes limestones, alternating with thin shaly 
partings. 
3. Black, brittle, bituminous limestone, or marble rock. 
4, Black, bituminous, hard, sheety shale. 
The exact relative thickness of these beds, remains yet to be determined; 
the two first members are approximately 50 to 60 feet; the third member, 
some 15 feet; and the fourth member, from 40 to 60 feet in thickness. 
The superposition in Wiley’s cove, renders it highly probable that the 
black limestone of the Oil-trough ridge, is also underlaid by a black shale, 
which is concealed, however, beneath the alluvium of White river, the 
black soil of which is partly derived from it, and, in part, from the wash- 
ings of the subcarboniferous limestones of the Oil. trough ridge. This is 
rendered still more probable, from the fact of dark shales and shaly lime- 
stones occurring under the same black limestones of the subcarboniferous 
group in Shield’s bluff, as may be seen in the section given of that hill, in 
a previous part of this Report, under the head of “‘ Independence county.” 
In the centre of Wiley’s cove, the grey beds of Archimedes limestone lie 
from 100 to 125 feet above the ‘general level of the farms, and the top of the 
black shale and base of the black marble at 60 to 70 feet above the same 
level. 
There is abundance of black chert, strewed in the water-courses of the 
cove, which approaches very nearly to the character and appearance of 
the black flints, found in the chalk formation of Europe; these appear to 
originate as segregations or concretions in the limestones, overlying the 
black shales, which, being more difficult of decomposition than their 
matrix, remain as gravel, while the imbedding rock, itself, has become a 
part of the rich, black soil of the cove. This is derived, in part, from 
the sibeatpontfarens limestone, and, in part, from the black shale. 
The deep mud holes in the road which leads up through the cove, have 
been washed out of and worked into the tenacious clay, derived from the 
disintegration of the black slate, and accumulated at the foot of the 
surrounding hills. 
Half a mile beyond Wiley’s cove, the black slate forms the bed of the 
Owl or Middle fork of Little Red river, with hard, heavy, dark, ferruginous 
