152 THE CLAYS OF ARKANSAS. 
The analyses of this kaolin show that except for the stains 
referred to above it is sufficiently pure for the manufacture of fine 
porcelain ware. It seems to be well adapted also for paper finishing. 
It also has high refractory properties, and in case it can not be found 
free from the impurities that would injure it as a china clay, it is still 
available for the manufacture of a high grade of fireproof articles. 
Prospecting for kaolin that lies in horizontally stratified beds, as 
do these of Pike County, is a very simple matter and will not be ex- 
pensive unless one happens upon thick deposits of the Pleistocene 
waterworn material that covers the surface of the ground. The 
accompanying diagram (fig. 15) is intended to show the method of 
occurrence of the kaolin with reference to the waterworn gravels of 
that region. 
A vertical section cut through these beds would show that they 
have some such relations as those indicated in the diagram. The 
kaolin lies in a horizontal bed, lea, and the sands, ss, clays, cl, etc., 
associated with it, are also horizontally bedded. These beds have 
been worn away from above and the great body of kaolin originally 
deposited has been removed. What remains is fragmentary and, 
Fig. 15.— Section of kaolin beds in Pike County. 
in the vicinity of the Vaughn Creek pits, at least, lies in the hilltops, but 
over the worn surface gravel beds, gr, have been spread out, covering 
the greater part of the surrounding country. This gravel varies 
greatly in thickness. At some places it is almost entirely wanting 
or is represented by only a few pebbles, while at others it has a 
thickness of 30 feet or more. It is at many places impossible to 
foresee the thickness of this gravel covering, for, as will be realized 
from the diagram, the thickness at a would give a miner no clue 
whatever to the thickness of the same deposit at b, and vice versa. 
The horizontality of the kaolin beds makes prospecting for them 
simple and cheap. It is only necessary to ascertain the elevation 
on the hillside at which the bed is to be exposed, judging from the 
elevation at which it occurs at known localities, and then to dig a 
trench up and down the face of the hill so as to crosscut the bed. 
This trench should pass entirely through the waterworn gravels and 
uncover the underlying beds. If the kaolin bed were perfectly 
horizontal such a trench would not be necessary, for a pit could be 
opened directly on the bed, but its position varies somewhat, and 
this variation makes the trench necessary. 
