182 THE CLAYS OF ARKANSAS, 
Magnesia (MgO) - - - - Trace. 
Potash (K 2 0) 0. 91 
Soda (Na 2 6) 80 
Manganese (MnO) Trace. 
Phosphoric acid (P 2 5 ) 00 
Loss on ignition 3. 32 
99,43 
Water at 115° C 1-40 
CLAY INDUSTRY. 
The only clay product manufactured in the county is common build- 
ing brick, made from the loess by the Choctaw Brick and Tile Com- 
pany, of Forrest City. The clay is hauled from the pit to the machine 
by a team and scraper, mixed in a steam pug mill, and molded in a 
Chambers end-cut, stiff-mud machine. The bricks are dried by steam, 
which requires one to two days. They are burned in up-draft kilns, 
having a capacity of 200,000 bricks. Wood is used as fuel. The plant 
has a capacity of 20,000 bricks a day. 
SALINE COUNTY. 
GENERAL GEOLOGY. 
Saline County has within its borders rocks of two widely different 
geologic ages. The northwestern portion of the county is covered 
with Paleozoic shales, sandstones, and novaculites, much folded or 
standing on edge, and intersected by a vast number of quartz veins; 
while the southeastern part is of soft and usually uncompacted and 
horizontally bedded Tertiary sands, clays, and gravels, except in parts 
of T. 2 S., R. 14 W., where eruptive rocks come to the surface. The 
line separating the Paleozoic and Tertiary areas runs through the 
county in a northeast-southwest direction. The St. Louis, Iron Moun- 
tain and Southern Railway follows the dividing line approximately 
parallel with and from 1 to 4 miles northwest of it. The region of 
Paleozoic shales and sandstones to the northwest was the dry land 
forming the shores during Tertiary times, when the sands and clays 
that lie to the southeast were being deposited in the waters which at 
that time covered all southern and eastern Arkansas. 
CLAY DEPOSITS. 
DISTRIBUTION OF THE CLAYS. 
In the northern and western parts of the county pottery clays are 
not likely to occur in abundance. They may possibly be found in 
occasional local pockets, where the clay shales have decayed, or in 
" slashes," where the water has leached out local accumulations; but 
the great pottery clay beds lie south and east of the old shore line re- 
