PULASKI COUNTY. 175 
On the Arch street turnpike a little west of the place where the new 
road joins the turnpike a bed of blue and red mottled joint clay is 
exposed in a gully washed out by the rain. 
For practical purposes these joint clays are not in much demand. 
Their tendency to " joint" or break up into small blocks whenever 
exposed to the weather makes their use difficult for any purpose 
except with great care, and even then no reliance could be placed 
upon them if worked alone. 
If judiciously mixed with other clays they might be used for some 
classes of ware. A mixture of the stiff red clay and the brownish- 
yellow surface clay has been successfully used for making flower pots. 
A few lengths of drain tile, turned upon the potter's wheel, dried and 
burned very satisfactorily. 
CHOCOLATE CLAYS. 
The chocolate clays are found only in remnants or patches in vari- 
ous parts of the district. 
At the union depot in Little Rock the chocolate clay forms the sur- 
face of the flat bottom of the cove in which the depot is situated. It 
has here a thickness of 2 to 3 feet. 
In the small valley formed by the stream crossing the Sweet Home 
turnpike and skirting the southern side of the gravel ridge in the SE. J 
sec. 11, T. 1 N., R 12 W., the chocolate clay is found on both sides of 
the stream and has a thickness of from 1 to 2 feet. On the hill at 
the tollgate between this stream and Fourche Bayou, about one-half 
mile from the place just mentioned, the same bed of chocolate clay 
appears. 
The following section shows the relation of the clays at this hill: 
Section at hill at tollgate. 
Feet. 
Chocolate clay 3 
Red clay * 6 
Blue clay. 
In Big Rock Bayou, in sec. 21, T. 2 N., R. 12 W., chocolate clay 2 
feet thick overlying a blue clay occupies the greater part of the bottom 
lands around the bayou. 
A partial analysis of the clay northwest of the union depot at 
Little Rock shows the following constituents: 
Analysis of chocolate-colored clay northwest of anion depot, Little Rock. 
[J. P. Smith, analyst.] 
Silica (Si0 2 ) 70. 05 
Alumina (A1 2 3 ) 14. 56 
Ferric oxide (Fe 2 3 ) 6.20 
Lime (CaO) 74 
Magnesia (MgO) 1.12 
