JOHNSON COUNTY. 121 
These shales are at some places hard and at others are soft and 
plastic. Where they have not been exposed long or favorably they 
are liable to be hard. In places they are disintegrated to a depth 
varying from 1 foot to 10 feet. Where these shales are soft and 
plastic they may be used without grinding for the manufacture of 
fire bricks, stove linings, paving bricks, and sewer pipes. If the 
shale is not soft and plastic it can be used only after being ground. 
The clays and clay shales usually accompanying the coal beds are 
liable to prove valuable as fire clays. 
The clay underlying the coal at the Stiewell mine No. 2 at Coal 
Hill is hard and shaly when freshly mined but readily breaks up under 
the influence of the weather. When burned this clay becomes white. 
Its thickness is uncertain, but it is said to range from 12 to 18 inches. 
At the Allister slope at Coal Hill the flooring is said to be a hard 
black shale, but no definite information could be obtained regarding 
its thickness. The waste material brought to the top contains a 
great quantity of black shale with plant impressions. 
At Payne's mine a clay from 4 to 6 inches thick underlies the coal. 
The upper half inch to 4 inches is a soft, dark shale and the lower 
1 to 2 inches is a soft yellow clay. 
The floor of the Felker mine is a soft shale, sagger clay. It is 
irregular in thickness, but averages from 4 to 5 feet. In some places 
in the mine this clay overlies the coal to a thickness of from 2 to 4 
inches. 
One mile northwest of Knoxville, on the Little Rock and Fort 
Smith Railway, the railway grade cuts a promising-looking exposure 
of shales. 
At Hartman station the railway has exposed the shales in a cut. 
In sec. 32, T. 10 N., R. 23 W., in the bank of the stream that runs 
south along the east side of the road near Clarksville College, the 
following section is exposed : 
Section in sec. 32, T. 10 N., R. 23 E. 
Ft. in. 
1. Dark -brown shale 2 
2. Disintegrated shale 1 4 
3. Coal 1 
4. Blue and snuff-colored shales (about) 15 
5. Black shales at the base. 
