100 THE CLAYS OF ARKANSAS. 
siliceous clay from 4 to 6 feet deep and about 140 yards long. When 
dry, this clay is white, but becomes bluish when wet. At both ends 
of the bank the clay loses its whitish color and becomes various shades 
of red. 
RESIDUAL CLAYS. 
It has already been pointed out in the chapter on the general geol- 
ogy of the State that the rocks of the coal regions of Arkansas which 
underlie the surface in Franklin County consist chiefly of alternate 
beds of sandstone, shale, fire clay, and coal. When argillaceous shales 
are exposed for a long time to weathering, they disintegrate so com- 
pletely that they form plastic clays available for the manufacture of 
pottery, sewer pipes, paving bricks, etc. All the plastic clays found 
among the hills of Franklin and adjoining counties, especially those 
found in the upland valleys, have been formed in this way. These 
rocks were originally deposited as horizontal beds of sediments; but 
in Franklin County they have been pressed into gentle folds and worn 
away by erosion until they must be regarded as only the badly muti- 
lated remains of the original deposits. But in spite of this folding and 
erosion and in spite of the talus of loose fragments and earth that cover 
the outcrops the beds may be readily traced by means of the geologic 
structure. 
Only a few localities at which potter's clays have been found and 
worked will be mentioned here, but these clays can be found in abun- 
dance in Franklin County if a demand for them should arise. 
On the Ozark-Kingston road, running east and west along the south 
side of sec. 20, T. 10 N., R. 26 W., blue and red shales of Carboniferous 
age appear in a ditch entering from the creek near the schoolhouse to 
the lane that turns north along the middle of the same section. These 
shales appear to be about 6 feet thick. About 30 paces farther north 
along this lane, in a small artificial opening, they are seen to have dis- 
integrated into a light-blue clay, 3 feet of which is exposed at this 
place. 
A clay or disintegrating shale, which appears to be the continuation 
of the shales last mentioned, occurs in the N. ^ NE. \ NE. \ sec. 29, 
T. 10 N., K. 26 W., as well as in the NW. \ NE. J sec. 29 and the 
NW. '! NE. \ sec. 28. 
TRANSPORTED CLAYS. 
At Webb City, in the NE. £ NE. f sec 11, T. 9 N., R. 27 W., a 
bed of pottery clay is exposed in a ditch along the Ozark-Caulksville 
road. This clay is almost white, is mottled with small streaks of red, 
and where exposed has a thickness of 2 feet. Being of Pleistocene age 
and forming a horizontal bed, it probably has a considerable areal 
extent. The bed is covered with the usual waterworn cherty gravel 
